From 116aa62bf54a39697e25f21d6cf6799f7faa1349 Mon Sep 17 00:00:00 2001 From: Georg Brandl Date: Wed, 15 Aug 2007 14:28:22 +0000 Subject: Move the 3k reST doc tree in place. --- Doc/ACKS.txt | 196 ++ Doc/Makefile | 62 + Doc/README.txt | 121 + Doc/TODO.txt | 6 + Doc/about.rst | 33 + Doc/bugs.rst | 59 + Doc/c-api/abstract.rst | 997 ++++++++ Doc/c-api/concrete.rst | 3676 +++++++++++++++++++++++++++ Doc/c-api/exceptions.rst | 515 ++++ Doc/c-api/index.rst | 33 + Doc/c-api/init.rst | 936 +++++++ Doc/c-api/intro.rst | 630 +++++ Doc/c-api/memory.rst | 207 ++ Doc/c-api/newtypes.rst | 1740 +++++++++++++ Doc/c-api/refcounting.rst | 74 + Doc/c-api/utilities.rst | 1030 ++++++++ Doc/c-api/veryhigh.rst | 278 ++ Doc/conf.py | 56 + Doc/contents.rst | 21 + Doc/copyright.rst | 19 + Doc/data/refcounts.dat | 1747 +++++++++++++ Doc/distutils/apiref.rst | 1976 ++++++++++++++ Doc/distutils/builtdist.rst | 405 +++ Doc/distutils/commandref.rst | 104 + Doc/distutils/configfile.rst | 130 + 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--git a/Doc/ACKS.txt b/Doc/ACKS.txt new file mode 100644 index 0000000..f695403 --- /dev/null +++ b/Doc/ACKS.txt @@ -0,0 +1,196 @@ +Contributors to the Python Documentation +---------------------------------------- + +This file lists people who have contributed in some way to the Python +documentation. It is probably not complete -- if you feel that you or +anyone else should be on this list, please let us know (send email to +docs@python.org), and we'll be glad to correct the problem. + +* Aahz +* Michael Abbott +* Steve Alexander +* Jim Ahlstrom +* Fred Allen +* A. Amoroso +* Pehr Anderson +* Oliver Andrich +* Jesús Cea Avión +* Daniel Barclay +* Chris Barker +* Don Bashford +* Anthony Baxter +* Bennett Benson +* Jonathan Black +* Robin Boerdijk +* Michal Bozon +* Aaron Brancotti +* Georg Brandl +* Keith Briggs +* Lee Busby +* Lorenzo M. Catucci +* Carl Cerecke +* Mauro Cicognini +* Gilles Civario +* Mike Clarkson +* Steve Clift +* Dave Cole +* Matthew Cowles +* Jeremy Craven +* Andrew Dalke +* Ben Darnell +* L. Peter Deutsch +* Robert Donohue +* Fred L. Drake, Jr. +* Jeff Epler +* Michael Ernst +* Blame Andy Eskilsson +* Carey Evans +* Martijn Faassen +* Carl Feynman +* Hernán Martínez Foffani +* Stefan Franke +* Jim Fulton +* Peter Funk +* Lele Gaifax +* Matthew Gallagher +* Ben Gertzfield +* Nadim Ghaznavi +* Jonathan Giddy +* Shelley Gooch +* Nathaniel Gray +* Grant Griffin +* Thomas Guettler +* Anders Hammarquist +* Mark Hammond +* Harald Hanche-Olsen +* Manus Hand +* Gerhard Häring +* Travis B. Hartwell +* Tim Hatch +* Janko Hauser +* Bernhard Herzog +* Magnus L. Hetland +* Konrad Hinsen +* Stefan Hoffmeister +* Albert Hofkamp +* Gregor Hoffleit +* Steve Holden +* Thomas Holenstein +* Gerrit Holl +* Rob Hooft +* Brian Hooper +* Randall Hopper +* Michael Hudson +* Eric Huss +* Jeremy Hylton +* Roger Irwin +* Jack Jansen +* Philip H. Jensen +* Pedro Diaz Jimenez +* Kent Johnson +* Lucas de Jonge +* Andreas Jung +* Robert Kern +* Jim Kerr +* Jan Kim +* Greg Kochanski +* Guido Kollerie +* Peter A. Koren +* Daniel Kozan +* Andrew M. Kuchling +* Dave Kuhlman +* Erno Kuusela +* Detlef Lannert +* Piers Lauder +* Glyph Lefkowitz +* Marc-André Lemburg +* Ulf A. Lindgren +* Everett Lipman +* Mirko Liss +* Martin von Löwis +* Fredrik Lundh +* Jeff MacDonald +* John Machin +* Andrew MacIntyre +* Vladimir Marangozov +* Vincent Marchetti +* Laura Matson +* Daniel May +* Doug Mennella +* Paolo Milani +* Skip Montanaro +* Paul Moore +* Ross Moore +* Sjoerd Mullender +* Dale Nagata +* Ng Pheng Siong +* Koray Oner +* Tomas Oppelstrup +* Denis S. Otkidach +* Zooko O'Whielacronx +* William Park +* Joonas Paalasmaa +* Harri Pasanen +* Bo Peng +* Tim Peters +* Christopher Petrilli +* Justin D. Pettit +* Chris Phoenix +* François Pinard +* Paul Prescod +* Eric S. Raymond +* Edward K. Ream +* Sean Reifschneider +* Bernhard Reiter +* Armin Rigo +* Wes Rishel +* Jim Roskind +* Guido van Rossum +* Donald Wallace Rouse II +* Nick Russo +* Chris Ryland +* Constantina S. +* Hugh Sasse +* Bob Savage +* Scott Schram +* Neil Schemenauer +* Barry Scott +* Joakim Sernbrant +* Justin Sheehy +* Michael Simcich +* Ionel Simionescu +* Gregory P. Smith +* Roy Smith +* Clay Spence +* Nicholas Spies +* Tage Stabell-Kulo +* Frank Stajano +* Anthony Starks +* Greg Stein +* Peter Stoehr +* Mark Summerfield +* Reuben Sumner +* Kalle Svensson +* Jim Tittsler +* Ville Vainio +* Martijn Vries +* Charles G. Waldman +* Greg Ward +* Barry Warsaw +* Corran Webster +* Glyn Webster +* Bob Weiner +* Eddy Welbourne +* Mats Wichmann +* Gerry Wiener +* Timothy Wild +* Collin Winter +* Blake Winton +* Dan Wolfe +* Steven Work +* Thomas Wouters +* Ka-Ping Yee +* Rory Yorke +* Moshe Zadka +* Milan Zamazal +* Cheng Zhang diff --git a/Doc/Makefile b/Doc/Makefile new file mode 100644 index 0000000..955fb68 --- /dev/null +++ b/Doc/Makefile @@ -0,0 +1,62 @@ +# +# Makefile for Python documentation +# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +# + +# You can set these variables from the command line. +PYTHON ?= python +SVNROOT ?= http://svn.python.org/projects +SPHINXOPTS ?= + +ALLSPHINXOPTS = -b$(BUILDER) -dbuild/doctrees $(SPHINXOPTS) . build/$(BUILDER) + +.PHONY: help checkout update build html web htmlhelp clean + +help: + @echo "Please use \`make ' where is one of" + @echo " html to make standalone HTML files" + @echo " web to make file usable by Sphinx.web" + @echo " htmlhelp to make HTML files and a HTML help project" + +checkout: + @if [ ! -d tools/sphinx ]; then \ + echo "Checking out Sphinx..."; \ + svn checkout $(SVNROOT)/doctools/trunk/sphinx tools/sphinx; \ + fi + @if [ ! -d tools/docutils ]; then \ + echo "Checking out Docutils..."; \ + svn checkout $(SVNROOT)/external/docutils-0.4/docutils tools/docutils; \ + fi + @if [ ! -d tools/pygments ]; then \ + echo "Checking out Pygments..."; \ + svn checkout $(SVNROOT)/external/Pygments-0.8.1/pygments tools/pygments; \ + fi + +update: + svn update tools/sphinx + svn update tools/docutils + svn update tools/pygments + +build: checkout + mkdir -p build/$(BUILDER) build/doctrees + $(PYTHON) tools/sphinx-build.py $(ALLSPHINXOPTS) + @echo + +html: BUILDER = html +html: build + @echo "Build finished. The HTML pages are in build/html." + +web: BUILDER = web +web: build + @echo "Build finished; now you can run" + @echo " PYTHONPATH=tools $(PYTHON) -m sphinx.web build/web" + @echo "to start the server." + +htmlhelp: BUILDER = htmlhelp +htmlhelp: build + @echo "Build finished; now you can run HTML Help Workshop with the" \ + "build/hhp/pydoc.hhp project file." + +clean: + -rm -rf build/* + -rm -rf tools/sphinx diff --git a/Doc/README.txt b/Doc/README.txt new file mode 100644 index 0000000..c566a4a --- /dev/null +++ b/Doc/README.txt @@ -0,0 +1,121 @@ +Python Documentation README +~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +This directory contains the reStructuredText (reST) sources to the Python +documentation. You don't need to build them yourself, prebuilt versions are +available at http://docs.python.org/download/. + +Documentation on the authoring Python documentation, including information about +both style and markup, is available in the "Documenting Python" chapter of the +documentation. There's also a chapter intended to point out differences to +those familiar with the previous docs written in LaTeX. + + +Building the docs +================= + +You need to install Python 2.5 or higher; the toolset used to build the docs are +written in Python. The toolset used to build the documentation is called +*Sphinx*, it is not included in this tree, but maintained separately in the +Python Subversion repository. Also needed are Jinja, a templating engine +(included in Sphinx as a Subversion external), and optionally Pygments, a code +highlighter. + + +Using make +---------- + +Luckily, a Makefile has been prepared so that on Unix, provided you have +installed Python and Subversion, you can just run :: + + make html + +to check out the necessary toolset in the `tools/` subdirectory and build the +HTML output files. To view the generated HTML, point your favorite browser at +the top-level index `build/html/index.html` after running "make". + +Available make targets are: + + * "html", which builds standalone HTML files for offline viewing. + + * "web", which builds files usable with the Sphinx.web application (used to + serve the docs online at http://docs.python.org/). + + * "htmlhelp", which builds HTML files and a HTML Help project file usable to + convert them into a single Compiled HTML (.chm) file -- these are popular + under Microsoft Windows, but very handy on every platform. + + To create the CHM file, you need to run the Microsoft HTML Help Workshop + over the generated project (.hhp) file. + +A "make update" updates the Subversion checkouts in `tools/`. + + +Without make +------------ + +You'll need to checkout the Sphinx package to the `tools/` directory:: + + svn co http://svn.python.org/projects/doctools/trunk/sphinx tools/sphinx + +Then, you need to install Docutils 0.4 (the SVN snapshot won't work), either +by checking it out via :: + + svn co http://svn.python.org/projects/external/docutils-0.4/docutils tools/docutils + +or by installing it from http://docutils.sf.net/. + +You can optionally also install Pygments, either as a checkout via :: + + svn co http://svn.python.org/projects/external/Pygments-0.8.1/pygments tools/pygments + +or from PyPI at http://pypi.python.org/pypi/Pygments. + + +Then, make an output directory, e.g. under `build/`, and run :: + + python tools/sphinx-build.py -b . build/ + +where `` is one of html, web or htmlhelp (for explanations see the make +targets above). + + +Contributing +============ + +For bugs in the content, the online version at http://docs.python.org/ has a +"suggest change" facility that can be used to correct errors in the source text +and submit them as a patch to the maintainers. + +Bugs in the toolset should be reported in the Python bug tracker at +http://bugs.python.org/. + +You can also send a mail to the Python Documentation Team at docs@python.org, +and we will process your request as soon as possible. + +If you want to help the Documentation Team, you are always welcome. Just send +a mail to docs@python.org. + + +Copyright notice +================ + +The Python source is copyrighted, but you can freely use and copy it +as long as you don't change or remove the copyright notice: + +---------------------------------------------------------------------- +Copyright (c) 2000-2007 Python Software Foundation. +All rights reserved. + +Copyright (c) 2000 BeOpen.com. +All rights reserved. + +Copyright (c) 1995-2000 Corporation for National Research Initiatives. +All rights reserved. + +Copyright (c) 1991-1995 Stichting Mathematisch Centrum. +All rights reserved. + +See the file "license.rst" for information on usage and redistribution +of this file, and for a DISCLAIMER OF ALL WARRANTIES. +---------------------------------------------------------------------- diff --git a/Doc/TODO.txt b/Doc/TODO.txt new file mode 100644 index 0000000..c8d3501 --- /dev/null +++ b/Doc/TODO.txt @@ -0,0 +1,6 @@ +To do +===== + +* split very large files and add toctrees +* finish "Documenting Python" +* care about XXX comments diff --git a/Doc/about.rst b/Doc/about.rst new file mode 100644 index 0000000..d3ce2dd --- /dev/null +++ b/Doc/about.rst @@ -0,0 +1,33 @@ +===================== +About these documents +===================== + + +These documents are generated from `reStructuredText +`_ sources by *Sphinx*, a document processor +specifically written for the Python documentation. + +In the online version of these documents, you can submit comments and suggest +changes directly on the documentation pages. + +Development of the documentation and its toolchain takes place on the +docs@python.org mailing list. We're always looking for volunteers wanting +to help with the docs, so feel free to send a mail there! + +Many thanks go to: + +* Fred L. Drake, Jr., the creator of the original Python documentation toolset + and writer of much of the content; +* the `docutils `_ project for creating + reStructuredText and the docutils suite; +* Fredrik Lundh for his `Alternative Python Reference + `_ project from which Sphinx got many good + ideas. + +See :ref:`reporting-bugs` for information how to report bugs in Python itself. + +.. including the ACKS file here so that it can be maintained separately +.. include:: ACKS.txt + +It is only with the input and contributions of the Python community +that Python has such wonderful documentation -- Thank You! diff --git a/Doc/bugs.rst b/Doc/bugs.rst new file mode 100644 index 0000000..f8f75c2 --- /dev/null +++ b/Doc/bugs.rst @@ -0,0 +1,59 @@ +.. _reporting-bugs: + +************************ +Reporting Bugs in Python +************************ + +Python is a mature programming language which has established a reputation for +stability. In order to maintain this reputation, the developers would like to +know of any deficiencies you find in Python. + +If you find errors in the documentation, please use either the "Add a comment" +or the "Suggest a change" features of the relevant page in the most recent +online documentation at http://docs.python.org/. + +All other bug reports should be submitted via the Python Bug Tracker +(http://bugs.python.org/). The bug tracker offers a Web form which allows +pertinent information to be entered and submitted to the developers. + +The first step in filing a report is to determine whether the problem has +already been reported. The advantage in doing so, aside from saving the +developers time, is that you learn what has been done to fix it; it may be that +the problem has already been fixed for the next release, or additional +information is needed (in which case you are welcome to provide it if you can!). +To do this, search the bug database using the search box on the top of the page. + +If the problem you're reporting is not already in the bug tracker, go back to +the Python Bug Tracker. If you don't already have a tracker account, select the +"Register" link in the sidebar and undergo the registration procedure. +Otherwise, if you're not logged in, enter your credentials and select "Login". +It is not possible to submit a bug report anonymously. + +Being now logged in, you can submit a bug. Select the "Create New" link in the +sidebar to open the bug reporting form. + +The submission form has a number of fields. For the "Title" field, enter a +*very* short description of the problem; less than ten words is good. In the +"Type" field, select the type of your problem; also select the "Component" and +"Versions" to which the bug relates. + +In the "Change Note" field, describe the problem in detail, including what you +expected to happen and what did happen. Be sure to include whether any +extension modules were involved, and what hardware and software platform you +were using (including version information as appropriate). + +Each bug report will be assigned to a developer who will determine what needs to +be done to correct the problem. You will receive an update each time action is +taken on the bug. + + +.. seealso:: + + `How to Report Bugs Effectively `_ + Article which goes into some detail about how to create a useful bug report. + This describes what kind of information is useful and why it is useful. + + `Bug Writing Guidelines `_ + Information about writing a good bug report. Some of this is specific to the + Mozilla project, but describes general good practices. + diff --git a/Doc/c-api/abstract.rst b/Doc/c-api/abstract.rst new file mode 100644 index 0000000..1a1ff13 --- /dev/null +++ b/Doc/c-api/abstract.rst @@ -0,0 +1,997 @@ +.. highlightlang:: c + + +.. _abstract: + +********************** +Abstract Objects Layer +********************** + +The functions in this chapter interact with Python objects regardless of their +type, or with wide classes of object types (e.g. all numerical types, or all +sequence types). When used on object types for which they do not apply, they +will raise a Python exception. + +It is not possible to use these functions on objects that are not properly +initialized, such as a list object that has been created by :cfunc:`PyList_New`, +but whose items have not been set to some non-\ ``NULL`` value yet. + + +.. _object: + +Object Protocol +=============== + + +.. cfunction:: int PyObject_Print(PyObject *o, FILE *fp, int flags) + + Print an object *o*, on file *fp*. Returns ``-1`` on error. The flags argument + is used to enable certain printing options. The only option currently supported + is :const:`Py_PRINT_RAW`; if given, the :func:`str` of the object is written + instead of the :func:`repr`. + + +.. cfunction:: int PyObject_HasAttrString(PyObject *o, const char *attr_name) + + Returns ``1`` if *o* has the attribute *attr_name*, and ``0`` otherwise. This + is equivalent to the Python expression ``hasattr(o, attr_name)``. This function + always succeeds. + + +.. cfunction:: PyObject* PyObject_GetAttrString(PyObject *o, const char *attr_name) + + Retrieve an attribute named *attr_name* from object *o*. Returns the attribute + value on success, or *NULL* on failure. This is the equivalent of the Python + expression ``o.attr_name``. + + +.. cfunction:: int PyObject_HasAttr(PyObject *o, PyObject *attr_name) + + Returns ``1`` if *o* has the attribute *attr_name*, and ``0`` otherwise. This + is equivalent to the Python expression ``hasattr(o, attr_name)``. This function + always succeeds. + + +.. cfunction:: PyObject* PyObject_GetAttr(PyObject *o, PyObject *attr_name) + + Retrieve an attribute named *attr_name* from object *o*. Returns the attribute + value on success, or *NULL* on failure. This is the equivalent of the Python + expression ``o.attr_name``. + + +.. cfunction:: int PyObject_SetAttrString(PyObject *o, const char *attr_name, PyObject *v) + + Set the value of the attribute named *attr_name*, for object *o*, to the value + *v*. Returns ``-1`` on failure. This is the equivalent of the Python statement + ``o.attr_name = v``. + + +.. cfunction:: int PyObject_SetAttr(PyObject *o, PyObject *attr_name, PyObject *v) + + Set the value of the attribute named *attr_name*, for object *o*, to the value + *v*. Returns ``-1`` on failure. This is the equivalent of the Python statement + ``o.attr_name = v``. + + +.. cfunction:: int PyObject_DelAttrString(PyObject *o, const char *attr_name) + + Delete attribute named *attr_name*, for object *o*. Returns ``-1`` on failure. + This is the equivalent of the Python statement: ``del o.attr_name``. + + +.. cfunction:: int PyObject_DelAttr(PyObject *o, PyObject *attr_name) + + Delete attribute named *attr_name*, for object *o*. Returns ``-1`` on failure. + This is the equivalent of the Python statement ``del o.attr_name``. + + +.. cfunction:: PyObject* PyObject_RichCompare(PyObject *o1, PyObject *o2, int opid) + + Compare the values of *o1* and *o2* using the operation specified by *opid*, + which must be one of :const:`Py_LT`, :const:`Py_LE`, :const:`Py_EQ`, + :const:`Py_NE`, :const:`Py_GT`, or :const:`Py_GE`, corresponding to ``<``, + ``<=``, ``==``, ``!=``, ``>``, or ``>=`` respectively. This is the equivalent of + the Python expression ``o1 op o2``, where ``op`` is the operator corresponding + to *opid*. Returns the value of the comparison on success, or *NULL* on failure. + + +.. cfunction:: int PyObject_RichCompareBool(PyObject *o1, PyObject *o2, int opid) + + Compare the values of *o1* and *o2* using the operation specified by *opid*, + which must be one of :const:`Py_LT`, :const:`Py_LE`, :const:`Py_EQ`, + :const:`Py_NE`, :const:`Py_GT`, or :const:`Py_GE`, corresponding to ``<``, + ``<=``, ``==``, ``!=``, ``>``, or ``>=`` respectively. Returns ``-1`` on error, + ``0`` if the result is false, ``1`` otherwise. This is the equivalent of the + Python expression ``o1 op o2``, where ``op`` is the operator corresponding to + *opid*. + + +.. cfunction:: int PyObject_Cmp(PyObject *o1, PyObject *o2, int *result) + + .. index:: builtin: cmp + + Compare the values of *o1* and *o2* using a routine provided by *o1*, if one + exists, otherwise with a routine provided by *o2*. The result of the comparison + is returned in *result*. Returns ``-1`` on failure. This is the equivalent of + the Python statement ``result = cmp(o1, o2)``. + + +.. cfunction:: int PyObject_Compare(PyObject *o1, PyObject *o2) + + .. index:: builtin: cmp + + Compare the values of *o1* and *o2* using a routine provided by *o1*, if one + exists, otherwise with a routine provided by *o2*. Returns the result of the + comparison on success. On error, the value returned is undefined; use + :cfunc:`PyErr_Occurred` to detect an error. This is equivalent to the Python + expression ``cmp(o1, o2)``. + + +.. cfunction:: PyObject* PyObject_Repr(PyObject *o) + + .. index:: builtin: repr + + Compute a string representation of object *o*. Returns the string + representation on success, *NULL* on failure. This is the equivalent of the + Python expression ``repr(o)``. Called by the :func:`repr` built-in function and + by reverse quotes. + + +.. cfunction:: PyObject* PyObject_Str(PyObject *o) + + .. index:: builtin: str + + Compute a string representation of object *o*. Returns the string + representation on success, *NULL* on failure. This is the equivalent of the + Python expression ``str(o)``. Called by the :func:`str` built-in function and + by the :keyword:`print` statement. + + +.. cfunction:: PyObject* PyObject_Unicode(PyObject *o) + + .. index:: builtin: unicode + + Compute a Unicode string representation of object *o*. Returns the Unicode + string representation on success, *NULL* on failure. This is the equivalent of + the Python expression ``unicode(o)``. Called by the :func:`unicode` built-in + function. + + +.. cfunction:: int PyObject_IsInstance(PyObject *inst, PyObject *cls) + + Returns ``1`` if *inst* is an instance of the class *cls* or a subclass of + *cls*, or ``0`` if not. On error, returns ``-1`` and sets an exception. If + *cls* is a type object rather than a class object, :cfunc:`PyObject_IsInstance` + returns ``1`` if *inst* is of type *cls*. If *cls* is a tuple, the check will + be done against every entry in *cls*. The result will be ``1`` when at least one + of the checks returns ``1``, otherwise it will be ``0``. If *inst* is not a + class instance and *cls* is neither a type object, nor a class object, nor a + tuple, *inst* must have a :attr:`__class__` attribute --- the class relationship + of the value of that attribute with *cls* will be used to determine the result + of this function. + + .. versionadded:: 2.1 + + .. versionchanged:: 2.2 + Support for a tuple as the second argument added. + +Subclass determination is done in a fairly straightforward way, but includes a +wrinkle that implementors of extensions to the class system may want to be aware +of. If :class:`A` and :class:`B` are class objects, :class:`B` is a subclass of +:class:`A` if it inherits from :class:`A` either directly or indirectly. If +either is not a class object, a more general mechanism is used to determine the +class relationship of the two objects. When testing if *B* is a subclass of +*A*, if *A* is *B*, :cfunc:`PyObject_IsSubclass` returns true. If *A* and *B* +are different objects, *B*'s :attr:`__bases__` attribute is searched in a +depth-first fashion for *A* --- the presence of the :attr:`__bases__` attribute +is considered sufficient for this determination. + + +.. cfunction:: int PyObject_IsSubclass(PyObject *derived, PyObject *cls) + + Returns ``1`` if the class *derived* is identical to or derived from the class + *cls*, otherwise returns ``0``. In case of an error, returns ``-1``. If *cls* + is a tuple, the check will be done against every entry in *cls*. The result will + be ``1`` when at least one of the checks returns ``1``, otherwise it will be + ``0``. If either *derived* or *cls* is not an actual class object (or tuple), + this function uses the generic algorithm described above. + + .. versionadded:: 2.1 + + .. versionchanged:: 2.3 + Older versions of Python did not support a tuple as the second argument. + + +.. cfunction:: int PyCallable_Check(PyObject *o) + + Determine if the object *o* is callable. Return ``1`` if the object is callable + and ``0`` otherwise. This function always succeeds. + + +.. cfunction:: PyObject* PyObject_Call(PyObject *callable_object, PyObject *args, PyObject *kw) + + Call a callable Python object *callable_object*, with arguments given by the + tuple *args*, and named arguments given by the dictionary *kw*. If no named + arguments are needed, *kw* may be *NULL*. *args* must not be *NULL*, use an + empty tuple if no arguments are needed. Returns the result of the call on + success, or *NULL* on failure. This is the equivalent of the Python expression + ``callable_object(*args, **kw)``. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyObject_CallObject(PyObject *callable_object, PyObject *args) + + Call a callable Python object *callable_object*, with arguments given by the + tuple *args*. If no arguments are needed, then *args* may be *NULL*. Returns + the result of the call on success, or *NULL* on failure. This is the equivalent + of the Python expression ``callable_object(*args)``. + + +.. cfunction:: PyObject* PyObject_CallFunction(PyObject *callable, char *format, ...) + + Call a callable Python object *callable*, with a variable number of C arguments. + The C arguments are described using a :cfunc:`Py_BuildValue` style format + string. The format may be *NULL*, indicating that no arguments are provided. + Returns the result of the call on success, or *NULL* on failure. This is the + equivalent of the Python expression ``callable(*args)``. Note that if you only + pass :ctype:`PyObject \*` args, :cfunc:`PyObject_CallFunctionObjArgs` is a + faster alternative. + + +.. cfunction:: PyObject* PyObject_CallMethod(PyObject *o, char *method, char *format, ...) + + Call the method named *method* of object *o* with a variable number of C + arguments. The C arguments are described by a :cfunc:`Py_BuildValue` format + string that should produce a tuple. The format may be *NULL*, indicating that + no arguments are provided. Returns the result of the call on success, or *NULL* + on failure. This is the equivalent of the Python expression ``o.method(args)``. + Note that if you only pass :ctype:`PyObject \*` args, + :cfunc:`PyObject_CallMethodObjArgs` is a faster alternative. + + +.. cfunction:: PyObject* PyObject_CallFunctionObjArgs(PyObject *callable, ..., NULL) + + Call a callable Python object *callable*, with a variable number of + :ctype:`PyObject\*` arguments. The arguments are provided as a variable number + of parameters followed by *NULL*. Returns the result of the call on success, or + *NULL* on failure. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyObject_CallMethodObjArgs(PyObject *o, PyObject *name, ..., NULL) + + Calls a method of the object *o*, where the name of the method is given as a + Python string object in *name*. It is called with a variable number of + :ctype:`PyObject\*` arguments. The arguments are provided as a variable number + of parameters followed by *NULL*. Returns the result of the call on success, or + *NULL* on failure. + + .. versionadded:: 2.2 + + +.. cfunction:: long PyObject_Hash(PyObject *o) + + .. index:: builtin: hash + + Compute and return the hash value of an object *o*. On failure, return ``-1``. + This is the equivalent of the Python expression ``hash(o)``. + + +.. cfunction:: int PyObject_IsTrue(PyObject *o) + + Returns ``1`` if the object *o* is considered to be true, and ``0`` otherwise. + This is equivalent to the Python expression ``not not o``. On failure, return + ``-1``. + + +.. cfunction:: int PyObject_Not(PyObject *o) + + Returns ``0`` if the object *o* is considered to be true, and ``1`` otherwise. + This is equivalent to the Python expression ``not o``. On failure, return + ``-1``. + + +.. cfunction:: PyObject* PyObject_Type(PyObject *o) + + .. index:: builtin: type + + When *o* is non-*NULL*, returns a type object corresponding to the object type + of object *o*. On failure, raises :exc:`SystemError` and returns *NULL*. This + is equivalent to the Python expression ``type(o)``. This function increments the + reference count of the return value. There's really no reason to use this + function instead of the common expression ``o->ob_type``, which returns a + pointer of type :ctype:`PyTypeObject\*`, except when the incremented reference + count is needed. + + +.. cfunction:: int PyObject_TypeCheck(PyObject *o, PyTypeObject *type) + + Return true if the object *o* is of type *type* or a subtype of *type*. Both + parameters must be non-*NULL*. + + .. versionadded:: 2.2 + + +.. cfunction:: Py_ssize_t PyObject_Length(PyObject *o) + Py_ssize_t PyObject_Size(PyObject *o) + + .. index:: builtin: len + + Return the length of object *o*. If the object *o* provides either the sequence + and mapping protocols, the sequence length is returned. On error, ``-1`` is + returned. This is the equivalent to the Python expression ``len(o)``. + + +.. cfunction:: PyObject* PyObject_GetItem(PyObject *o, PyObject *key) + + Return element of *o* corresponding to the object *key* or *NULL* on failure. + This is the equivalent of the Python expression ``o[key]``. + + +.. cfunction:: int PyObject_SetItem(PyObject *o, PyObject *key, PyObject *v) + + Map the object *key* to the value *v*. Returns ``-1`` on failure. This is the + equivalent of the Python statement ``o[key] = v``. + + +.. cfunction:: int PyObject_DelItem(PyObject *o, PyObject *key) + + Delete the mapping for *key* from *o*. Returns ``-1`` on failure. This is the + equivalent of the Python statement ``del o[key]``. + + +.. cfunction:: int PyObject_AsFileDescriptor(PyObject *o) + + Derives a file-descriptor from a Python object. If the object is an integer or + long integer, its value is returned. If not, the object's :meth:`fileno` method + is called if it exists; the method must return an integer or long integer, which + is returned as the file descriptor value. Returns ``-1`` on failure. + + +.. cfunction:: PyObject* PyObject_Dir(PyObject *o) + + This is equivalent to the Python expression ``dir(o)``, returning a (possibly + empty) list of strings appropriate for the object argument, or *NULL* if there + was an error. If the argument is *NULL*, this is like the Python ``dir()``, + returning the names of the current locals; in this case, if no execution frame + is active then *NULL* is returned but :cfunc:`PyErr_Occurred` will return false. + + +.. cfunction:: PyObject* PyObject_GetIter(PyObject *o) + + This is equivalent to the Python expression ``iter(o)``. It returns a new + iterator for the object argument, or the object itself if the object is already + an iterator. Raises :exc:`TypeError` and returns *NULL* if the object cannot be + iterated. + + +.. _number: + +Number Protocol +=============== + + +.. cfunction:: int PyNumber_Check(PyObject *o) + + Returns ``1`` if the object *o* provides numeric protocols, and false otherwise. + This function always succeeds. + + +.. cfunction:: PyObject* PyNumber_Add(PyObject *o1, PyObject *o2) + + Returns the result of adding *o1* and *o2*, or *NULL* on failure. This is the + equivalent of the Python expression ``o1 + o2``. + + +.. cfunction:: PyObject* PyNumber_Subtract(PyObject *o1, PyObject *o2) + + Returns the result of subtracting *o2* from *o1*, or *NULL* on failure. This is + the equivalent of the Python expression ``o1 - o2``. + + +.. cfunction:: PyObject* PyNumber_Multiply(PyObject *o1, PyObject *o2) + + Returns the result of multiplying *o1* and *o2*, or *NULL* on failure. This is + the equivalent of the Python expression ``o1 * o2``. + + +.. cfunction:: PyObject* PyNumber_Divide(PyObject *o1, PyObject *o2) + + Returns the result of dividing *o1* by *o2*, or *NULL* on failure. This is the + equivalent of the Python expression ``o1 / o2``. + + +.. cfunction:: PyObject* PyNumber_FloorDivide(PyObject *o1, PyObject *o2) + + Return the floor of *o1* divided by *o2*, or *NULL* on failure. This is + equivalent to the "classic" division of integers. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyNumber_TrueDivide(PyObject *o1, PyObject *o2) + + Return a reasonable approximation for the mathematical value of *o1* divided by + *o2*, or *NULL* on failure. The return value is "approximate" because binary + floating point numbers are approximate; it is not possible to represent all real + numbers in base two. This function can return a floating point value when + passed two integers. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyNumber_Remainder(PyObject *o1, PyObject *o2) + + Returns the remainder of dividing *o1* by *o2*, or *NULL* on failure. This is + the equivalent of the Python expression ``o1 % o2``. + + +.. cfunction:: PyObject* PyNumber_Divmod(PyObject *o1, PyObject *o2) + + .. index:: builtin: divmod + + See the built-in function :func:`divmod`. Returns *NULL* on failure. This is + the equivalent of the Python expression ``divmod(o1, o2)``. + + +.. cfunction:: PyObject* PyNumber_Power(PyObject *o1, PyObject *o2, PyObject *o3) + + .. index:: builtin: pow + + See the built-in function :func:`pow`. Returns *NULL* on failure. This is the + equivalent of the Python expression ``pow(o1, o2, o3)``, where *o3* is optional. + If *o3* is to be ignored, pass :cdata:`Py_None` in its place (passing *NULL* for + *o3* would cause an illegal memory access). + + +.. cfunction:: PyObject* PyNumber_Negative(PyObject *o) + + Returns the negation of *o* on success, or *NULL* on failure. This is the + equivalent of the Python expression ``-o``. + + +.. cfunction:: PyObject* PyNumber_Positive(PyObject *o) + + Returns *o* on success, or *NULL* on failure. This is the equivalent of the + Python expression ``+o``. + + +.. cfunction:: PyObject* PyNumber_Absolute(PyObject *o) + + .. index:: builtin: abs + + Returns the absolute value of *o*, or *NULL* on failure. This is the equivalent + of the Python expression ``abs(o)``. + + +.. cfunction:: PyObject* PyNumber_Invert(PyObject *o) + + Returns the bitwise negation of *o* on success, or *NULL* on failure. This is + the equivalent of the Python expression ``~o``. + + +.. cfunction:: PyObject* PyNumber_Lshift(PyObject *o1, PyObject *o2) + + Returns the result of left shifting *o1* by *o2* on success, or *NULL* on + failure. This is the equivalent of the Python expression ``o1 << o2``. + + +.. cfunction:: PyObject* PyNumber_Rshift(PyObject *o1, PyObject *o2) + + Returns the result of right shifting *o1* by *o2* on success, or *NULL* on + failure. This is the equivalent of the Python expression ``o1 >> o2``. + + +.. cfunction:: PyObject* PyNumber_And(PyObject *o1, PyObject *o2) + + Returns the "bitwise and" of *o1* and *o2* on success and *NULL* on failure. + This is the equivalent of the Python expression ``o1 & o2``. + + +.. cfunction:: PyObject* PyNumber_Xor(PyObject *o1, PyObject *o2) + + Returns the "bitwise exclusive or" of *o1* by *o2* on success, or *NULL* on + failure. This is the equivalent of the Python expression ``o1 ^ o2``. + + +.. cfunction:: PyObject* PyNumber_Or(PyObject *o1, PyObject *o2) + + Returns the "bitwise or" of *o1* and *o2* on success, or *NULL* on failure. + This is the equivalent of the Python expression ``o1 | o2``. + + +.. cfunction:: PyObject* PyNumber_InPlaceAdd(PyObject *o1, PyObject *o2) + + Returns the result of adding *o1* and *o2*, or *NULL* on failure. The operation + is done *in-place* when *o1* supports it. This is the equivalent of the Python + statement ``o1 += o2``. + + +.. cfunction:: PyObject* PyNumber_InPlaceSubtract(PyObject *o1, PyObject *o2) + + Returns the result of subtracting *o2* from *o1*, or *NULL* on failure. The + operation is done *in-place* when *o1* supports it. This is the equivalent of + the Python statement ``o1 -= o2``. + + +.. cfunction:: PyObject* PyNumber_InPlaceMultiply(PyObject *o1, PyObject *o2) + + Returns the result of multiplying *o1* and *o2*, or *NULL* on failure. The + operation is done *in-place* when *o1* supports it. This is the equivalent of + the Python statement ``o1 *= o2``. + + +.. cfunction:: PyObject* PyNumber_InPlaceDivide(PyObject *o1, PyObject *o2) + + Returns the result of dividing *o1* by *o2*, or *NULL* on failure. The + operation is done *in-place* when *o1* supports it. This is the equivalent of + the Python statement ``o1 /= o2``. + + +.. cfunction:: PyObject* PyNumber_InPlaceFloorDivide(PyObject *o1, PyObject *o2) + + Returns the mathematical floor of dividing *o1* by *o2*, or *NULL* on failure. + The operation is done *in-place* when *o1* supports it. This is the equivalent + of the Python statement ``o1 //= o2``. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyNumber_InPlaceTrueDivide(PyObject *o1, PyObject *o2) + + Return a reasonable approximation for the mathematical value of *o1* divided by + *o2*, or *NULL* on failure. The return value is "approximate" because binary + floating point numbers are approximate; it is not possible to represent all real + numbers in base two. This function can return a floating point value when + passed two integers. The operation is done *in-place* when *o1* supports it. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyNumber_InPlaceRemainder(PyObject *o1, PyObject *o2) + + Returns the remainder of dividing *o1* by *o2*, or *NULL* on failure. The + operation is done *in-place* when *o1* supports it. This is the equivalent of + the Python statement ``o1 %= o2``. + + +.. cfunction:: PyObject* PyNumber_InPlacePower(PyObject *o1, PyObject *o2, PyObject *o3) + + .. index:: builtin: pow + + See the built-in function :func:`pow`. Returns *NULL* on failure. The operation + is done *in-place* when *o1* supports it. This is the equivalent of the Python + statement ``o1 **= o2`` when o3 is :cdata:`Py_None`, or an in-place variant of + ``pow(o1, o2, o3)`` otherwise. If *o3* is to be ignored, pass :cdata:`Py_None` + in its place (passing *NULL* for *o3* would cause an illegal memory access). + + +.. cfunction:: PyObject* PyNumber_InPlaceLshift(PyObject *o1, PyObject *o2) + + Returns the result of left shifting *o1* by *o2* on success, or *NULL* on + failure. The operation is done *in-place* when *o1* supports it. This is the + equivalent of the Python statement ``o1 <<= o2``. + + +.. cfunction:: PyObject* PyNumber_InPlaceRshift(PyObject *o1, PyObject *o2) + + Returns the result of right shifting *o1* by *o2* on success, or *NULL* on + failure. The operation is done *in-place* when *o1* supports it. This is the + equivalent of the Python statement ``o1 >>= o2``. + + +.. cfunction:: PyObject* PyNumber_InPlaceAnd(PyObject *o1, PyObject *o2) + + Returns the "bitwise and" of *o1* and *o2* on success and *NULL* on failure. The + operation is done *in-place* when *o1* supports it. This is the equivalent of + the Python statement ``o1 &= o2``. + + +.. cfunction:: PyObject* PyNumber_InPlaceXor(PyObject *o1, PyObject *o2) + + Returns the "bitwise exclusive or" of *o1* by *o2* on success, or *NULL* on + failure. The operation is done *in-place* when *o1* supports it. This is the + equivalent of the Python statement ``o1 ^= o2``. + + +.. cfunction:: PyObject* PyNumber_InPlaceOr(PyObject *o1, PyObject *o2) + + Returns the "bitwise or" of *o1* and *o2* on success, or *NULL* on failure. The + operation is done *in-place* when *o1* supports it. This is the equivalent of + the Python statement ``o1 |= o2``. + + +.. cfunction:: PyObject* PyNumber_Int(PyObject *o) + + .. index:: builtin: int + + Returns the *o* converted to an integer object on success, or *NULL* on failure. + If the argument is outside the integer range a long object will be returned + instead. This is the equivalent of the Python expression ``int(o)``. + + +.. cfunction:: PyObject* PyNumber_Long(PyObject *o) + + .. index:: builtin: long + + Returns the *o* converted to a long integer object on success, or *NULL* on + failure. This is the equivalent of the Python expression ``long(o)``. + + +.. cfunction:: PyObject* PyNumber_Float(PyObject *o) + + .. index:: builtin: float + + Returns the *o* converted to a float object on success, or *NULL* on failure. + This is the equivalent of the Python expression ``float(o)``. + + +.. cfunction:: PyObject* PyNumber_Index(PyObject *o) + + Returns the *o* converted to a Python int or long on success or *NULL* with a + TypeError exception raised on failure. + + .. versionadded:: 2.5 + + +.. cfunction:: Py_ssize_t PyNumber_AsSsize_t(PyObject *o, PyObject *exc) + + Returns *o* converted to a Py_ssize_t value if *o* can be interpreted as an + integer. If *o* can be converted to a Python int or long but the attempt to + convert to a Py_ssize_t value would raise an :exc:`OverflowError`, then the + *exc* argument is the type of exception that will be raised (usually + :exc:`IndexError` or :exc:`OverflowError`). If *exc* is *NULL*, then the + exception is cleared and the value is clipped to *PY_SSIZE_T_MIN* for a negative + integer or *PY_SSIZE_T_MAX* for a positive integer. + + .. versionadded:: 2.5 + + +.. cfunction:: int PyIndex_Check(PyObject *o) + + Returns True if *o* is an index integer (has the nb_index slot of the + tp_as_number structure filled in). + + .. versionadded:: 2.5 + + +.. _sequence: + +Sequence Protocol +================= + + +.. cfunction:: int PySequence_Check(PyObject *o) + + Return ``1`` if the object provides sequence protocol, and ``0`` otherwise. + This function always succeeds. + + +.. cfunction:: Py_ssize_t PySequence_Size(PyObject *o) + + .. index:: builtin: len + + Returns the number of objects in sequence *o* on success, and ``-1`` on failure. + For objects that do not provide sequence protocol, this is equivalent to the + Python expression ``len(o)``. + + +.. cfunction:: Py_ssize_t PySequence_Length(PyObject *o) + + Alternate name for :cfunc:`PySequence_Size`. + + +.. cfunction:: PyObject* PySequence_Concat(PyObject *o1, PyObject *o2) + + Return the concatenation of *o1* and *o2* on success, and *NULL* on failure. + This is the equivalent of the Python expression ``o1 + o2``. + + +.. cfunction:: PyObject* PySequence_Repeat(PyObject *o, Py_ssize_t count) + + Return the result of repeating sequence object *o* *count* times, or *NULL* on + failure. This is the equivalent of the Python expression ``o * count``. + + +.. cfunction:: PyObject* PySequence_InPlaceConcat(PyObject *o1, PyObject *o2) + + Return the concatenation of *o1* and *o2* on success, and *NULL* on failure. + The operation is done *in-place* when *o1* supports it. This is the equivalent + of the Python expression ``o1 += o2``. + + +.. cfunction:: PyObject* PySequence_InPlaceRepeat(PyObject *o, Py_ssize_t count) + + Return the result of repeating sequence object *o* *count* times, or *NULL* on + failure. The operation is done *in-place* when *o* supports it. This is the + equivalent of the Python expression ``o *= count``. + + +.. cfunction:: PyObject* PySequence_GetItem(PyObject *o, Py_ssize_t i) + + Return the *i*th element of *o*, or *NULL* on failure. This is the equivalent of + the Python expression ``o[i]``. + + +.. cfunction:: PyObject* PySequence_GetSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2) + + Return the slice of sequence object *o* between *i1* and *i2*, or *NULL* on + failure. This is the equivalent of the Python expression ``o[i1:i2]``. + + +.. cfunction:: int PySequence_SetItem(PyObject *o, Py_ssize_t i, PyObject *v) + + Assign object *v* to the *i*th element of *o*. Returns ``-1`` on failure. This + is the equivalent of the Python statement ``o[i] = v``. This function *does + not* steal a reference to *v*. + + +.. cfunction:: int PySequence_DelItem(PyObject *o, Py_ssize_t i) + + Delete the *i*th element of object *o*. Returns ``-1`` on failure. This is the + equivalent of the Python statement ``del o[i]``. + + +.. cfunction:: int PySequence_SetSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2, PyObject *v) + + Assign the sequence object *v* to the slice in sequence object *o* from *i1* to + *i2*. This is the equivalent of the Python statement ``o[i1:i2] = v``. + + +.. cfunction:: int PySequence_DelSlice(PyObject *o, Py_ssize_t i1, Py_ssize_t i2) + + Delete the slice in sequence object *o* from *i1* to *i2*. Returns ``-1`` on + failure. This is the equivalent of the Python statement ``del o[i1:i2]``. + + +.. cfunction:: Py_ssize_t PySequence_Count(PyObject *o, PyObject *value) + + Return the number of occurrences of *value* in *o*, that is, return the number + of keys for which ``o[key] == value``. On failure, return ``-1``. This is + equivalent to the Python expression ``o.count(value)``. + + +.. cfunction:: int PySequence_Contains(PyObject *o, PyObject *value) + + Determine if *o* contains *value*. If an item in *o* is equal to *value*, + return ``1``, otherwise return ``0``. On error, return ``-1``. This is + equivalent to the Python expression ``value in o``. + + +.. cfunction:: Py_ssize_t PySequence_Index(PyObject *o, PyObject *value) + + Return the first index *i* for which ``o[i] == value``. On error, return + ``-1``. This is equivalent to the Python expression ``o.index(value)``. + + +.. cfunction:: PyObject* PySequence_List(PyObject *o) + + Return a list object with the same contents as the arbitrary sequence *o*. The + returned list is guaranteed to be new. + + +.. cfunction:: PyObject* PySequence_Tuple(PyObject *o) + + .. index:: builtin: tuple + + Return a tuple object with the same contents as the arbitrary sequence *o* or + *NULL* on failure. If *o* is a tuple, a new reference will be returned, + otherwise a tuple will be constructed with the appropriate contents. This is + equivalent to the Python expression ``tuple(o)``. + + +.. cfunction:: PyObject* PySequence_Fast(PyObject *o, const char *m) + + Returns the sequence *o* as a tuple, unless it is already a tuple or list, in + which case *o* is returned. Use :cfunc:`PySequence_Fast_GET_ITEM` to access the + members of the result. Returns *NULL* on failure. If the object is not a + sequence, raises :exc:`TypeError` with *m* as the message text. + + +.. cfunction:: PyObject* PySequence_Fast_GET_ITEM(PyObject *o, Py_ssize_t i) + + Return the *i*th element of *o*, assuming that *o* was returned by + :cfunc:`PySequence_Fast`, *o* is not *NULL*, and that *i* is within bounds. + + +.. cfunction:: PyObject** PySequence_Fast_ITEMS(PyObject *o) + + Return the underlying array of PyObject pointers. Assumes that *o* was returned + by :cfunc:`PySequence_Fast` and *o* is not *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PySequence_ITEM(PyObject *o, Py_ssize_t i) + + Return the *i*th element of *o* or *NULL* on failure. Macro form of + :cfunc:`PySequence_GetItem` but without checking that + :cfunc:`PySequence_Check(o)` is true and without adjustment for negative + indices. + + .. versionadded:: 2.3 + + +.. cfunction:: Py_ssize_t PySequence_Fast_GET_SIZE(PyObject *o) + + Returns the length of *o*, assuming that *o* was returned by + :cfunc:`PySequence_Fast` and that *o* is not *NULL*. The size can also be + gotten by calling :cfunc:`PySequence_Size` on *o*, but + :cfunc:`PySequence_Fast_GET_SIZE` is faster because it can assume *o* is a list + or tuple. + + +.. _mapping: + +Mapping Protocol +================ + + +.. cfunction:: int PyMapping_Check(PyObject *o) + + Return ``1`` if the object provides mapping protocol, and ``0`` otherwise. This + function always succeeds. + + +.. cfunction:: Py_ssize_t PyMapping_Length(PyObject *o) + + .. index:: builtin: len + + Returns the number of keys in object *o* on success, and ``-1`` on failure. For + objects that do not provide mapping protocol, this is equivalent to the Python + expression ``len(o)``. + + +.. cfunction:: int PyMapping_DelItemString(PyObject *o, char *key) + + Remove the mapping for object *key* from the object *o*. Return ``-1`` on + failure. This is equivalent to the Python statement ``del o[key]``. + + +.. cfunction:: int PyMapping_DelItem(PyObject *o, PyObject *key) + + Remove the mapping for object *key* from the object *o*. Return ``-1`` on + failure. This is equivalent to the Python statement ``del o[key]``. + + +.. cfunction:: int PyMapping_HasKeyString(PyObject *o, char *key) + + On success, return ``1`` if the mapping object has the key *key* and ``0`` + otherwise. This is equivalent to the Python expression ``o.has_key(key)``. + This function always succeeds. + + +.. cfunction:: int PyMapping_HasKey(PyObject *o, PyObject *key) + + Return ``1`` if the mapping object has the key *key* and ``0`` otherwise. This + is equivalent to the Python expression ``o.has_key(key)``. This function always + succeeds. + + +.. cfunction:: PyObject* PyMapping_Keys(PyObject *o) + + On success, return a list of the keys in object *o*. On failure, return *NULL*. + This is equivalent to the Python expression ``o.keys()``. + + +.. cfunction:: PyObject* PyMapping_Values(PyObject *o) + + On success, return a list of the values in object *o*. On failure, return + *NULL*. This is equivalent to the Python expression ``o.values()``. + + +.. cfunction:: PyObject* PyMapping_Items(PyObject *o) + + On success, return a list of the items in object *o*, where each item is a tuple + containing a key-value pair. On failure, return *NULL*. This is equivalent to + the Python expression ``o.items()``. + + +.. cfunction:: PyObject* PyMapping_GetItemString(PyObject *o, char *key) + + Return element of *o* corresponding to the object *key* or *NULL* on failure. + This is the equivalent of the Python expression ``o[key]``. + + +.. cfunction:: int PyMapping_SetItemString(PyObject *o, char *key, PyObject *v) + + Map the object *key* to the value *v* in object *o*. Returns ``-1`` on failure. + This is the equivalent of the Python statement ``o[key] = v``. + + +.. _iterator: + +Iterator Protocol +================= + +.. versionadded:: 2.2 + +There are only a couple of functions specifically for working with iterators. + + +.. cfunction:: int PyIter_Check(PyObject *o) + + Return true if the object *o* supports the iterator protocol. + + +.. cfunction:: PyObject* PyIter_Next(PyObject *o) + + Return the next value from the iteration *o*. If the object is an iterator, + this retrieves the next value from the iteration, and returns *NULL* with no + exception set if there are no remaining items. If the object is not an + iterator, :exc:`TypeError` is raised, or if there is an error in retrieving the + item, returns *NULL* and passes along the exception. + +To write a loop which iterates over an iterator, the C code should look +something like this:: + + PyObject *iterator = PyObject_GetIter(obj); + PyObject *item; + + if (iterator == NULL) { + /* propagate error */ + } + + while (item = PyIter_Next(iterator)) { + /* do something with item */ + ... + /* release reference when done */ + Py_DECREF(item); + } + + Py_DECREF(iterator); + + if (PyErr_Occurred()) { + /* propagate error */ + } + else { + /* continue doing useful work */ + } + + +.. _abstract-buffer: + +Buffer Protocol +=============== + + +.. cfunction:: int PyObject_AsCharBuffer(PyObject *obj, const char **buffer, Py_ssize_t *buffer_len) + + Returns a pointer to a read-only memory location useable as character- based + input. The *obj* argument must support the single-segment character buffer + interface. On success, returns ``0``, sets *buffer* to the memory location and + *buffer_len* to the buffer length. Returns ``-1`` and sets a :exc:`TypeError` + on error. + + .. versionadded:: 1.6 + + +.. cfunction:: int PyObject_AsReadBuffer(PyObject *obj, const void **buffer, Py_ssize_t *buffer_len) + + Returns a pointer to a read-only memory location containing arbitrary data. The + *obj* argument must support the single-segment readable buffer interface. On + success, returns ``0``, sets *buffer* to the memory location and *buffer_len* to + the buffer length. Returns ``-1`` and sets a :exc:`TypeError` on error. + + .. versionadded:: 1.6 + + +.. cfunction:: int PyObject_CheckReadBuffer(PyObject *o) + + Returns ``1`` if *o* supports the single-segment readable buffer interface. + Otherwise returns ``0``. + + .. versionadded:: 2.2 + + +.. cfunction:: int PyObject_AsWriteBuffer(PyObject *obj, void **buffer, Py_ssize_t *buffer_len) + + Returns a pointer to a writeable memory location. The *obj* argument must + support the single-segment, character buffer interface. On success, returns + ``0``, sets *buffer* to the memory location and *buffer_len* to the buffer + length. Returns ``-1`` and sets a :exc:`TypeError` on error. + + .. versionadded:: 1.6 + diff --git a/Doc/c-api/concrete.rst b/Doc/c-api/concrete.rst new file mode 100644 index 0000000..052785c --- /dev/null +++ b/Doc/c-api/concrete.rst @@ -0,0 +1,3676 @@ +.. highlightlang:: c + + +.. _concrete: + +********************** +Concrete Objects Layer +********************** + +The functions in this chapter are specific to certain Python object types. +Passing them an object of the wrong type is not a good idea; if you receive an +object from a Python program and you are not sure that it has the right type, +you must perform a type check first; for example, to check that an object is a +dictionary, use :cfunc:`PyDict_Check`. The chapter is structured like the +"family tree" of Python object types. + +.. warning:: + + While the functions described in this chapter carefully check the type of the + objects which are passed in, many of them do not check for *NULL* being passed + instead of a valid object. Allowing *NULL* to be passed in can cause memory + access violations and immediate termination of the interpreter. + + +.. _fundamental: + +Fundamental Objects +=================== + +This section describes Python type objects and the singleton object ``None``. + + +.. _typeobjects: + +Type Objects +------------ + +.. index:: object: type + + +.. ctype:: PyTypeObject + + The C structure of the objects used to describe built-in types. + + +.. cvar:: PyObject* PyType_Type + + .. index:: single: TypeType (in module types) + + This is the type object for type objects; it is the same object as ``type`` and + ``types.TypeType`` in the Python layer. + + +.. cfunction:: int PyType_Check(PyObject *o) + + Return true if the object *o* is a type object, including instances of types + derived from the standard type object. Return false in all other cases. + + +.. cfunction:: int PyType_CheckExact(PyObject *o) + + Return true if the object *o* is a type object, but not a subtype of the + standard type object. Return false in all other cases. + + .. versionadded:: 2.2 + + +.. cfunction:: int PyType_HasFeature(PyObject *o, int feature) + + Return true if the type object *o* sets the feature *feature*. Type features + are denoted by single bit flags. + + +.. cfunction:: int PyType_IS_GC(PyObject *o) + + Return true if the type object includes support for the cycle detector; this + tests the type flag :const:`Py_TPFLAGS_HAVE_GC`. + + .. versionadded:: 2.0 + + +.. cfunction:: int PyType_IsSubtype(PyTypeObject *a, PyTypeObject *b) + + Return true if *a* is a subtype of *b*. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyType_GenericAlloc(PyTypeObject *type, Py_ssize_t nitems) + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyType_GenericNew(PyTypeObject *type, PyObject *args, PyObject *kwds) + + .. versionadded:: 2.2 + + +.. cfunction:: int PyType_Ready(PyTypeObject *type) + + Finalize a type object. This should be called on all type objects to finish + their initialization. This function is responsible for adding inherited slots + from a type's base class. Return ``0`` on success, or return ``-1`` and sets an + exception on error. + + .. versionadded:: 2.2 + + +.. _noneobject: + +The None Object +--------------- + +.. index:: object: None + +Note that the :ctype:`PyTypeObject` for ``None`` is not directly exposed in the +Python/C API. Since ``None`` is a singleton, testing for object identity (using +``==`` in C) is sufficient. There is no :cfunc:`PyNone_Check` function for the +same reason. + + +.. cvar:: PyObject* Py_None + + The Python ``None`` object, denoting lack of value. This object has no methods. + It needs to be treated just like any other object with respect to reference + counts. + + +.. cmacro:: Py_RETURN_NONE + + Properly handle returning :cdata:`Py_None` from within a C function. + + .. versionadded:: 2.4 + + +.. _numericobjects: + +Numeric Objects +=============== + +.. index:: object: numeric + + +.. _intobjects: + +Plain Integer Objects +--------------------- + +.. index:: object: integer + + +.. ctype:: PyIntObject + + This subtype of :ctype:`PyObject` represents a Python integer object. + + +.. cvar:: PyTypeObject PyInt_Type + + .. index:: single: IntType (in modules types) + + This instance of :ctype:`PyTypeObject` represents the Python plain integer type. + This is the same object as ``int`` and ``types.IntType``. + + +.. cfunction:: int PyInt_Check(PyObject *o) + + Return true if *o* is of type :cdata:`PyInt_Type` or a subtype of + :cdata:`PyInt_Type`. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyInt_CheckExact(PyObject *o) + + Return true if *o* is of type :cdata:`PyInt_Type`, but not a subtype of + :cdata:`PyInt_Type`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyInt_FromString(char *str, char **pend, int base) + + Return a new :ctype:`PyIntObject` or :ctype:`PyLongObject` based on the string + value in *str*, which is interpreted according to the radix in *base*. If + *pend* is non-*NULL*, ``*pend`` will point to the first character in *str* which + follows the representation of the number. If *base* is ``0``, the radix will be + determined based on the leading characters of *str*: if *str* starts with + ``'0x'`` or ``'0X'``, radix 16 will be used; if *str* starts with ``'0'``, radix + 8 will be used; otherwise radix 10 will be used. If *base* is not ``0``, it + must be between ``2`` and ``36``, inclusive. Leading spaces are ignored. If + there are no digits, :exc:`ValueError` will be raised. If the string represents + a number too large to be contained within the machine's :ctype:`long int` type + and overflow warnings are being suppressed, a :ctype:`PyLongObject` will be + returned. If overflow warnings are not being suppressed, *NULL* will be + returned in this case. + + +.. cfunction:: PyObject* PyInt_FromLong(long ival) + + Create a new integer object with a value of *ival*. + + The current implementation keeps an array of integer objects for all integers + between ``-5`` and ``256``, when you create an int in that range you actually + just get back a reference to the existing object. So it should be possible to + change the value of ``1``. I suspect the behaviour of Python in this case is + undefined. :-) + + +.. cfunction:: PyObject* PyInt_FromSsize_t(Py_ssize_t ival) + + Create a new integer object with a value of *ival*. If the value exceeds + ``LONG_MAX``, a long integer object is returned. + + .. versionadded:: 2.5 + + +.. cfunction:: long PyInt_AsLong(PyObject *io) + + Will first attempt to cast the object to a :ctype:`PyIntObject`, if it is not + already one, and then return its value. If there is an error, ``-1`` is + returned, and the caller should check ``PyErr_Occurred()`` to find out whether + there was an error, or whether the value just happened to be -1. + + +.. cfunction:: long PyInt_AS_LONG(PyObject *io) + + Return the value of the object *io*. No error checking is performed. + + +.. cfunction:: unsigned long PyInt_AsUnsignedLongMask(PyObject *io) + + Will first attempt to cast the object to a :ctype:`PyIntObject` or + :ctype:`PyLongObject`, if it is not already one, and then return its value as + unsigned long. This function does not check for overflow. + + .. versionadded:: 2.3 + + +.. cfunction:: unsigned PY_LONG_LONG PyInt_AsUnsignedLongLongMask(PyObject *io) + + Will first attempt to cast the object to a :ctype:`PyIntObject` or + :ctype:`PyLongObject`, if it is not already one, and then return its value as + unsigned long long, without checking for overflow. + + .. versionadded:: 2.3 + + +.. cfunction:: Py_ssize_t PyInt_AsSsize_t(PyObject *io) + + Will first attempt to cast the object to a :ctype:`PyIntObject` or + :ctype:`PyLongObject`, if it is not already one, and then return its value as + :ctype:`Py_ssize_t`. + + .. versionadded:: 2.5 + + +.. cfunction:: long PyInt_GetMax() + + .. index:: single: LONG_MAX + + Return the system's idea of the largest integer it can handle + (:const:`LONG_MAX`, as defined in the system header files). + + +.. _boolobjects: + +Boolean Objects +--------------- + +Booleans in Python are implemented as a subclass of integers. There are only +two booleans, :const:`Py_False` and :const:`Py_True`. As such, the normal +creation and deletion functions don't apply to booleans. The following macros +are available, however. + + +.. cfunction:: int PyBool_Check(PyObject *o) + + Return true if *o* is of type :cdata:`PyBool_Type`. + + .. versionadded:: 2.3 + + +.. cvar:: PyObject* Py_False + + The Python ``False`` object. This object has no methods. It needs to be + treated just like any other object with respect to reference counts. + + +.. cvar:: PyObject* Py_True + + The Python ``True`` object. This object has no methods. It needs to be treated + just like any other object with respect to reference counts. + + +.. cmacro:: Py_RETURN_FALSE + + Return :const:`Py_False` from a function, properly incrementing its reference + count. + + .. versionadded:: 2.4 + + +.. cmacro:: Py_RETURN_TRUE + + Return :const:`Py_True` from a function, properly incrementing its reference + count. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PyBool_FromLong(long v) + + Return a new reference to :const:`Py_True` or :const:`Py_False` depending on the + truth value of *v*. + + .. versionadded:: 2.3 + + +.. _longobjects: + +Long Integer Objects +-------------------- + +.. index:: object: long integer + + +.. ctype:: PyLongObject + + This subtype of :ctype:`PyObject` represents a Python long integer object. + + +.. cvar:: PyTypeObject PyLong_Type + + .. index:: single: LongType (in modules types) + + This instance of :ctype:`PyTypeObject` represents the Python long integer type. + This is the same object as ``long`` and ``types.LongType``. + + +.. cfunction:: int PyLong_Check(PyObject *p) + + Return true if its argument is a :ctype:`PyLongObject` or a subtype of + :ctype:`PyLongObject`. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyLong_CheckExact(PyObject *p) + + Return true if its argument is a :ctype:`PyLongObject`, but not a subtype of + :ctype:`PyLongObject`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyLong_FromLong(long v) + + Return a new :ctype:`PyLongObject` object from *v*, or *NULL* on failure. + + +.. cfunction:: PyObject* PyLong_FromUnsignedLong(unsigned long v) + + Return a new :ctype:`PyLongObject` object from a C :ctype:`unsigned long`, or + *NULL* on failure. + + +.. cfunction:: PyObject* PyLong_FromLongLong(PY_LONG_LONG v) + + Return a new :ctype:`PyLongObject` object from a C :ctype:`long long`, or *NULL* + on failure. + + +.. cfunction:: PyObject* PyLong_FromUnsignedLongLong(unsigned PY_LONG_LONG v) + + Return a new :ctype:`PyLongObject` object from a C :ctype:`unsigned long long`, + or *NULL* on failure. + + +.. cfunction:: PyObject* PyLong_FromDouble(double v) + + Return a new :ctype:`PyLongObject` object from the integer part of *v*, or + *NULL* on failure. + + +.. cfunction:: PyObject* PyLong_FromString(char *str, char **pend, int base) + + Return a new :ctype:`PyLongObject` based on the string value in *str*, which is + interpreted according to the radix in *base*. If *pend* is non-*NULL*, + ``*pend`` will point to the first character in *str* which follows the + representation of the number. If *base* is ``0``, the radix will be determined + based on the leading characters of *str*: if *str* starts with ``'0x'`` or + ``'0X'``, radix 16 will be used; if *str* starts with ``'0'``, radix 8 will be + used; otherwise radix 10 will be used. If *base* is not ``0``, it must be + between ``2`` and ``36``, inclusive. Leading spaces are ignored. If there are + no digits, :exc:`ValueError` will be raised. + + +.. cfunction:: PyObject* PyLong_FromUnicode(Py_UNICODE *u, Py_ssize_t length, int base) + + Convert a sequence of Unicode digits to a Python long integer value. The first + parameter, *u*, points to the first character of the Unicode string, *length* + gives the number of characters, and *base* is the radix for the conversion. The + radix must be in the range [2, 36]; if it is out of range, :exc:`ValueError` + will be raised. + + .. versionadded:: 1.6 + + +.. cfunction:: PyObject* PyLong_FromVoidPtr(void *p) + + Create a Python integer or long integer from the pointer *p*. The pointer value + can be retrieved from the resulting value using :cfunc:`PyLong_AsVoidPtr`. + + .. versionadded:: 1.5.2 + + .. versionchanged:: 2.5 + If the integer is larger than LONG_MAX, a positive long integer is returned. + + +.. cfunction:: long PyLong_AsLong(PyObject *pylong) + + .. index:: + single: LONG_MAX + single: OverflowError (built-in exception) + + Return a C :ctype:`long` representation of the contents of *pylong*. If + *pylong* is greater than :const:`LONG_MAX`, an :exc:`OverflowError` is raised. + + +.. cfunction:: unsigned long PyLong_AsUnsignedLong(PyObject *pylong) + + .. index:: + single: ULONG_MAX + single: OverflowError (built-in exception) + + Return a C :ctype:`unsigned long` representation of the contents of *pylong*. + If *pylong* is greater than :const:`ULONG_MAX`, an :exc:`OverflowError` is + raised. + + +.. cfunction:: PY_LONG_LONG PyLong_AsLongLong(PyObject *pylong) + + Return a C :ctype:`long long` from a Python long integer. If *pylong* cannot be + represented as a :ctype:`long long`, an :exc:`OverflowError` will be raised. + + .. versionadded:: 2.2 + + +.. cfunction:: unsigned PY_LONG_LONG PyLong_AsUnsignedLongLong(PyObject *pylong) + + Return a C :ctype:`unsigned long long` from a Python long integer. If *pylong* + cannot be represented as an :ctype:`unsigned long long`, an :exc:`OverflowError` + will be raised if the value is positive, or a :exc:`TypeError` will be raised if + the value is negative. + + .. versionadded:: 2.2 + + +.. cfunction:: unsigned long PyLong_AsUnsignedLongMask(PyObject *io) + + Return a C :ctype:`unsigned long` from a Python long integer, without checking + for overflow. + + .. versionadded:: 2.3 + + +.. cfunction:: unsigned PY_LONG_LONG PyLong_AsUnsignedLongLongMask(PyObject *io) + + Return a C :ctype:`unsigned long long` from a Python long integer, without + checking for overflow. + + .. versionadded:: 2.3 + + +.. cfunction:: double PyLong_AsDouble(PyObject *pylong) + + Return a C :ctype:`double` representation of the contents of *pylong*. If + *pylong* cannot be approximately represented as a :ctype:`double`, an + :exc:`OverflowError` exception is raised and ``-1.0`` will be returned. + + +.. cfunction:: void* PyLong_AsVoidPtr(PyObject *pylong) + + Convert a Python integer or long integer *pylong* to a C :ctype:`void` pointer. + If *pylong* cannot be converted, an :exc:`OverflowError` will be raised. This + is only assured to produce a usable :ctype:`void` pointer for values created + with :cfunc:`PyLong_FromVoidPtr`. + + .. versionadded:: 1.5.2 + + .. versionchanged:: 2.5 + For values outside 0..LONG_MAX, both signed and unsigned integers are acccepted. + + +.. _floatobjects: + +Floating Point Objects +---------------------- + +.. index:: object: floating point + + +.. ctype:: PyFloatObject + + This subtype of :ctype:`PyObject` represents a Python floating point object. + + +.. cvar:: PyTypeObject PyFloat_Type + + .. index:: single: FloatType (in modules types) + + This instance of :ctype:`PyTypeObject` represents the Python floating point + type. This is the same object as ``float`` and ``types.FloatType``. + + +.. cfunction:: int PyFloat_Check(PyObject *p) + + Return true if its argument is a :ctype:`PyFloatObject` or a subtype of + :ctype:`PyFloatObject`. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyFloat_CheckExact(PyObject *p) + + Return true if its argument is a :ctype:`PyFloatObject`, but not a subtype of + :ctype:`PyFloatObject`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyFloat_FromString(PyObject *str) + + Create a :ctype:`PyFloatObject` object based on the string value in *str*, or + *NULL* on failure. + + +.. cfunction:: PyObject* PyFloat_FromDouble(double v) + + Create a :ctype:`PyFloatObject` object from *v*, or *NULL* on failure. + + +.. cfunction:: double PyFloat_AsDouble(PyObject *pyfloat) + + Return a C :ctype:`double` representation of the contents of *pyfloat*. If + *pyfloat* is not a Python floating point object but has a :meth:`__float__` + method, this method will first be called to convert *pyfloat* into a float. + + +.. cfunction:: double PyFloat_AS_DOUBLE(PyObject *pyfloat) + + Return a C :ctype:`double` representation of the contents of *pyfloat*, but + without error checking. + + +.. _complexobjects: + +Complex Number Objects +---------------------- + +.. index:: object: complex number + +Python's complex number objects are implemented as two distinct types when +viewed from the C API: one is the Python object exposed to Python programs, and +the other is a C structure which represents the actual complex number value. +The API provides functions for working with both. + + +Complex Numbers as C Structures +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Note that the functions which accept these structures as parameters and return +them as results do so *by value* rather than dereferencing them through +pointers. This is consistent throughout the API. + + +.. ctype:: Py_complex + + The C structure which corresponds to the value portion of a Python complex + number object. Most of the functions for dealing with complex number objects + use structures of this type as input or output values, as appropriate. It is + defined as:: + + typedef struct { + double real; + double imag; + } Py_complex; + + +.. cfunction:: Py_complex _Py_c_sum(Py_complex left, Py_complex right) + + Return the sum of two complex numbers, using the C :ctype:`Py_complex` + representation. + + +.. cfunction:: Py_complex _Py_c_diff(Py_complex left, Py_complex right) + + Return the difference between two complex numbers, using the C + :ctype:`Py_complex` representation. + + +.. cfunction:: Py_complex _Py_c_neg(Py_complex complex) + + Return the negation of the complex number *complex*, using the C + :ctype:`Py_complex` representation. + + +.. cfunction:: Py_complex _Py_c_prod(Py_complex left, Py_complex right) + + Return the product of two complex numbers, using the C :ctype:`Py_complex` + representation. + + +.. cfunction:: Py_complex _Py_c_quot(Py_complex dividend, Py_complex divisor) + + Return the quotient of two complex numbers, using the C :ctype:`Py_complex` + representation. + + +.. cfunction:: Py_complex _Py_c_pow(Py_complex num, Py_complex exp) + + Return the exponentiation of *num* by *exp*, using the C :ctype:`Py_complex` + representation. + + +Complex Numbers as Python Objects +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + + +.. ctype:: PyComplexObject + + This subtype of :ctype:`PyObject` represents a Python complex number object. + + +.. cvar:: PyTypeObject PyComplex_Type + + This instance of :ctype:`PyTypeObject` represents the Python complex number + type. It is the same object as ``complex`` and ``types.ComplexType``. + + +.. cfunction:: int PyComplex_Check(PyObject *p) + + Return true if its argument is a :ctype:`PyComplexObject` or a subtype of + :ctype:`PyComplexObject`. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyComplex_CheckExact(PyObject *p) + + Return true if its argument is a :ctype:`PyComplexObject`, but not a subtype of + :ctype:`PyComplexObject`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyComplex_FromCComplex(Py_complex v) + + Create a new Python complex number object from a C :ctype:`Py_complex` value. + + +.. cfunction:: PyObject* PyComplex_FromDoubles(double real, double imag) + + Return a new :ctype:`PyComplexObject` object from *real* and *imag*. + + +.. cfunction:: double PyComplex_RealAsDouble(PyObject *op) + + Return the real part of *op* as a C :ctype:`double`. + + +.. cfunction:: double PyComplex_ImagAsDouble(PyObject *op) + + Return the imaginary part of *op* as a C :ctype:`double`. + + +.. cfunction:: Py_complex PyComplex_AsCComplex(PyObject *op) + + Return the :ctype:`Py_complex` value of the complex number *op*. + + .. versionchanged:: 2.6 + If *op* is not a Python complex number object but has a :meth:`__complex__` + method, this method will first be called to convert *op* to a Python complex + number object. + + +.. _sequenceobjects: + +Sequence Objects +================ + +.. index:: object: sequence + +Generic operations on sequence objects were discussed in the previous chapter; +this section deals with the specific kinds of sequence objects that are +intrinsic to the Python language. + + +.. _stringobjects: + +String Objects +-------------- + +These functions raise :exc:`TypeError` when expecting a string parameter and are +called with a non-string parameter. + +.. index:: object: string + + +.. ctype:: PyStringObject + + This subtype of :ctype:`PyObject` represents a Python string object. + + +.. cvar:: PyTypeObject PyString_Type + + .. index:: single: StringType (in module types) + + This instance of :ctype:`PyTypeObject` represents the Python string type; it is + the same object as ``str`` and ``types.StringType`` in the Python layer. . + + +.. cfunction:: int PyString_Check(PyObject *o) + + Return true if the object *o* is a string object or an instance of a subtype of + the string type. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyString_CheckExact(PyObject *o) + + Return true if the object *o* is a string object, but not an instance of a + subtype of the string type. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyString_FromString(const char *v) + + Return a new string object with a copy of the string *v* as value on success, + and *NULL* on failure. The parameter *v* must not be *NULL*; it will not be + checked. + + +.. cfunction:: PyObject* PyString_FromStringAndSize(const char *v, Py_ssize_t len) + + Return a new string object with a copy of the string *v* as value and length + *len* on success, and *NULL* on failure. If *v* is *NULL*, the contents of the + string are uninitialized. + + +.. cfunction:: PyObject* PyString_FromFormat(const char *format, ...) + + Take a C :cfunc:`printf`\ -style *format* string and a variable number of + arguments, calculate the size of the resulting Python string and return a string + with the values formatted into it. The variable arguments must be C types and + must correspond exactly to the format characters in the *format* string. The + following format characters are allowed: + + .. % This should be exactly the same as the table in PyErr_Format. + .. % One should just refer to the other. + .. % The descriptions for %zd and %zu are wrong, but the truth is complicated + .. % because not all compilers support the %z width modifier -- we fake it + .. % when necessary via interpolating PY_FORMAT_SIZE_T. + .. % %u, %lu, %zu should have "new in Python 2.5" blurbs. + + +-------------------+---------------+--------------------------------+ + | Format Characters | Type | Comment | + +===================+===============+================================+ + | :attr:`%%` | *n/a* | The literal % character. | + +-------------------+---------------+--------------------------------+ + | :attr:`%c` | int | A single character, | + | | | represented as an C int. | + +-------------------+---------------+--------------------------------+ + | :attr:`%d` | int | Exactly equivalent to | + | | | ``printf("%d")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%u` | unsigned int | Exactly equivalent to | + | | | ``printf("%u")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%ld` | long | Exactly equivalent to | + | | | ``printf("%ld")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%lu` | unsigned long | Exactly equivalent to | + | | | ``printf("%lu")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%zd` | Py_ssize_t | Exactly equivalent to | + | | | ``printf("%zd")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%zu` | size_t | Exactly equivalent to | + | | | ``printf("%zu")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%i` | int | Exactly equivalent to | + | | | ``printf("%i")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%x` | int | Exactly equivalent to | + | | | ``printf("%x")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%s` | char\* | A null-terminated C character | + | | | array. | + +-------------------+---------------+--------------------------------+ + | :attr:`%p` | void\* | The hex representation of a C | + | | | pointer. Mostly equivalent to | + | | | ``printf("%p")`` except that | + | | | it is guaranteed to start with | + | | | the literal ``0x`` regardless | + | | | of what the platform's | + | | | ``printf`` yields. | + +-------------------+---------------+--------------------------------+ + + An unrecognized format character causes all the rest of the format string to be + copied as-is to the result string, and any extra arguments discarded. + + +.. cfunction:: PyObject* PyString_FromFormatV(const char *format, va_list vargs) + + Identical to :func:`PyString_FromFormat` except that it takes exactly two + arguments. + + +.. cfunction:: Py_ssize_t PyString_Size(PyObject *string) + + Return the length of the string in string object *string*. + + +.. cfunction:: Py_ssize_t PyString_GET_SIZE(PyObject *string) + + Macro form of :cfunc:`PyString_Size` but without error checking. + + +.. cfunction:: char* PyString_AsString(PyObject *string) + + Return a NUL-terminated representation of the contents of *string*. The pointer + refers to the internal buffer of *string*, not a copy. The data must not be + modified in any way, unless the string was just created using + ``PyString_FromStringAndSize(NULL, size)``. It must not be deallocated. If + *string* is a Unicode object, this function computes the default encoding of + *string* and operates on that. If *string* is not a string object at all, + :cfunc:`PyString_AsString` returns *NULL* and raises :exc:`TypeError`. + + +.. cfunction:: char* PyString_AS_STRING(PyObject *string) + + Macro form of :cfunc:`PyString_AsString` but without error checking. Only + string objects are supported; no Unicode objects should be passed. + + +.. cfunction:: int PyString_AsStringAndSize(PyObject *obj, char **buffer, Py_ssize_t *length) + + Return a NUL-terminated representation of the contents of the object *obj* + through the output variables *buffer* and *length*. + + The function accepts both string and Unicode objects as input. For Unicode + objects it returns the default encoded version of the object. If *length* is + *NULL*, the resulting buffer may not contain NUL characters; if it does, the + function returns ``-1`` and a :exc:`TypeError` is raised. + + The buffer refers to an internal string buffer of *obj*, not a copy. The data + must not be modified in any way, unless the string was just created using + ``PyString_FromStringAndSize(NULL, size)``. It must not be deallocated. If + *string* is a Unicode object, this function computes the default encoding of + *string* and operates on that. If *string* is not a string object at all, + :cfunc:`PyString_AsStringAndSize` returns ``-1`` and raises :exc:`TypeError`. + + +.. cfunction:: void PyString_Concat(PyObject **string, PyObject *newpart) + + Create a new string object in *\*string* containing the contents of *newpart* + appended to *string*; the caller will own the new reference. The reference to + the old value of *string* will be stolen. If the new string cannot be created, + the old reference to *string* will still be discarded and the value of + *\*string* will be set to *NULL*; the appropriate exception will be set. + + +.. cfunction:: void PyString_ConcatAndDel(PyObject **string, PyObject *newpart) + + Create a new string object in *\*string* containing the contents of *newpart* + appended to *string*. This version decrements the reference count of *newpart*. + + +.. cfunction:: int _PyString_Resize(PyObject **string, Py_ssize_t newsize) + + A way to resize a string object even though it is "immutable". Only use this to + build up a brand new string object; don't use this if the string may already be + known in other parts of the code. It is an error to call this function if the + refcount on the input string object is not one. Pass the address of an existing + string object as an lvalue (it may be written into), and the new size desired. + On success, *\*string* holds the resized string object and ``0`` is returned; + the address in *\*string* may differ from its input value. If the reallocation + fails, the original string object at *\*string* is deallocated, *\*string* is + set to *NULL*, a memory exception is set, and ``-1`` is returned. + + +.. cfunction:: PyObject* PyString_Format(PyObject *format, PyObject *args) + + Return a new string object from *format* and *args*. Analogous to ``format % + args``. The *args* argument must be a tuple. + + +.. cfunction:: void PyString_InternInPlace(PyObject **string) + + Intern the argument *\*string* in place. The argument must be the address of a + pointer variable pointing to a Python string object. If there is an existing + interned string that is the same as *\*string*, it sets *\*string* to it + (decrementing the reference count of the old string object and incrementing the + reference count of the interned string object), otherwise it leaves *\*string* + alone and interns it (incrementing its reference count). (Clarification: even + though there is a lot of talk about reference counts, think of this function as + reference-count-neutral; you own the object after the call if and only if you + owned it before the call.) + + +.. cfunction:: PyObject* PyString_InternFromString(const char *v) + + A combination of :cfunc:`PyString_FromString` and + :cfunc:`PyString_InternInPlace`, returning either a new string object that has + been interned, or a new ("owned") reference to an earlier interned string object + with the same value. + + +.. cfunction:: PyObject* PyString_Decode(const char *s, Py_ssize_t size, const char *encoding, const char *errors) + + Create an object by decoding *size* bytes of the encoded buffer *s* using the + codec registered for *encoding*. *encoding* and *errors* have the same meaning + as the parameters of the same name in the :func:`unicode` built-in function. + The codec to be used is looked up using the Python codec registry. Return + *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyString_AsDecodedObject(PyObject *str, const char *encoding, const char *errors) + + Decode a string object by passing it to the codec registered for *encoding* and + return the result as Python object. *encoding* and *errors* have the same + meaning as the parameters of the same name in the string :meth:`encode` method. + The codec to be used is looked up using the Python codec registry. Return *NULL* + if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyString_Encode(const char *s, Py_ssize_t size, const char *encoding, const char *errors) + + Encode the :ctype:`char` buffer of the given size by passing it to the codec + registered for *encoding* and return a Python object. *encoding* and *errors* + have the same meaning as the parameters of the same name in the string + :meth:`encode` method. The codec to be used is looked up using the Python codec + registry. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyString_AsEncodedObject(PyObject *str, const char *encoding, const char *errors) + + Encode a string object using the codec registered for *encoding* and return the + result as Python object. *encoding* and *errors* have the same meaning as the + parameters of the same name in the string :meth:`encode` method. The codec to be + used is looked up using the Python codec registry. Return *NULL* if an exception + was raised by the codec. + + +.. _unicodeobjects: + +Unicode Objects +--------------- + +.. sectionauthor:: Marc-Andre Lemburg + + +These are the basic Unicode object types used for the Unicode implementation in +Python: + +.. % --- Unicode Type ------------------------------------------------------- + + +.. ctype:: Py_UNICODE + + This type represents the storage type which is used by Python internally as + basis for holding Unicode ordinals. Python's default builds use a 16-bit type + for :ctype:`Py_UNICODE` and store Unicode values internally as UCS2. It is also + possible to build a UCS4 version of Python (most recent Linux distributions come + with UCS4 builds of Python). These builds then use a 32-bit type for + :ctype:`Py_UNICODE` and store Unicode data internally as UCS4. On platforms + where :ctype:`wchar_t` is available and compatible with the chosen Python + Unicode build variant, :ctype:`Py_UNICODE` is a typedef alias for + :ctype:`wchar_t` to enhance native platform compatibility. On all other + platforms, :ctype:`Py_UNICODE` is a typedef alias for either :ctype:`unsigned + short` (UCS2) or :ctype:`unsigned long` (UCS4). + +Note that UCS2 and UCS4 Python builds are not binary compatible. Please keep +this in mind when writing extensions or interfaces. + + +.. ctype:: PyUnicodeObject + + This subtype of :ctype:`PyObject` represents a Python Unicode object. + + +.. cvar:: PyTypeObject PyUnicode_Type + + This instance of :ctype:`PyTypeObject` represents the Python Unicode type. It + is exposed to Python code as ``unicode`` and ``types.UnicodeType``. + +The following APIs are really C macros and can be used to do fast checks and to +access internal read-only data of Unicode objects: + + +.. cfunction:: int PyUnicode_Check(PyObject *o) + + Return true if the object *o* is a Unicode object or an instance of a Unicode + subtype. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyUnicode_CheckExact(PyObject *o) + + Return true if the object *o* is a Unicode object, but not an instance of a + subtype. + + .. versionadded:: 2.2 + + +.. cfunction:: Py_ssize_t PyUnicode_GET_SIZE(PyObject *o) + + Return the size of the object. *o* has to be a :ctype:`PyUnicodeObject` (not + checked). + + +.. cfunction:: Py_ssize_t PyUnicode_GET_DATA_SIZE(PyObject *o) + + Return the size of the object's internal buffer in bytes. *o* has to be a + :ctype:`PyUnicodeObject` (not checked). + + +.. cfunction:: Py_UNICODE* PyUnicode_AS_UNICODE(PyObject *o) + + Return a pointer to the internal :ctype:`Py_UNICODE` buffer of the object. *o* + has to be a :ctype:`PyUnicodeObject` (not checked). + + +.. cfunction:: const char* PyUnicode_AS_DATA(PyObject *o) + + Return a pointer to the internal buffer of the object. *o* has to be a + :ctype:`PyUnicodeObject` (not checked). + +Unicode provides many different character properties. The most often needed ones +are available through these macros which are mapped to C functions depending on +the Python configuration. + +.. % --- Unicode character properties --------------------------------------- + + +.. cfunction:: int Py_UNICODE_ISSPACE(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is a whitespace character. + + +.. cfunction:: int Py_UNICODE_ISLOWER(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is a lowercase character. + + +.. cfunction:: int Py_UNICODE_ISUPPER(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is an uppercase character. + + +.. cfunction:: int Py_UNICODE_ISTITLE(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is a titlecase character. + + +.. cfunction:: int Py_UNICODE_ISLINEBREAK(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is a linebreak character. + + +.. cfunction:: int Py_UNICODE_ISDECIMAL(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is a decimal character. + + +.. cfunction:: int Py_UNICODE_ISDIGIT(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is a digit character. + + +.. cfunction:: int Py_UNICODE_ISNUMERIC(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is a numeric character. + + +.. cfunction:: int Py_UNICODE_ISALPHA(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is an alphabetic character. + + +.. cfunction:: int Py_UNICODE_ISALNUM(Py_UNICODE ch) + + Return 1 or 0 depending on whether *ch* is an alphanumeric character. + +These APIs can be used for fast direct character conversions: + + +.. cfunction:: Py_UNICODE Py_UNICODE_TOLOWER(Py_UNICODE ch) + + Return the character *ch* converted to lower case. + + +.. cfunction:: Py_UNICODE Py_UNICODE_TOUPPER(Py_UNICODE ch) + + Return the character *ch* converted to upper case. + + +.. cfunction:: Py_UNICODE Py_UNICODE_TOTITLE(Py_UNICODE ch) + + Return the character *ch* converted to title case. + + +.. cfunction:: int Py_UNICODE_TODECIMAL(Py_UNICODE ch) + + Return the character *ch* converted to a decimal positive integer. Return + ``-1`` if this is not possible. This macro does not raise exceptions. + + +.. cfunction:: int Py_UNICODE_TODIGIT(Py_UNICODE ch) + + Return the character *ch* converted to a single digit integer. Return ``-1`` if + this is not possible. This macro does not raise exceptions. + + +.. cfunction:: double Py_UNICODE_TONUMERIC(Py_UNICODE ch) + + Return the character *ch* converted to a double. Return ``-1.0`` if this is not + possible. This macro does not raise exceptions. + +To create Unicode objects and access their basic sequence properties, use these +APIs: + +.. % --- Plain Py_UNICODE --------------------------------------------------- + + +.. cfunction:: PyObject* PyUnicode_FromUnicode(const Py_UNICODE *u, Py_ssize_t size) + + Create a Unicode Object from the Py_UNICODE buffer *u* of the given size. *u* + may be *NULL* which causes the contents to be undefined. It is the user's + responsibility to fill in the needed data. The buffer is copied into the new + object. If the buffer is not *NULL*, the return value might be a shared object. + Therefore, modification of the resulting Unicode object is only allowed when *u* + is *NULL*. + + +.. cfunction:: PyObject* PyUnicode_FromStringAndSize(const char *u, Py_ssize_t size) + + Create a Unicode Object from the char buffer *u*. The bytes will be interpreted + as being UTF-8 encoded. *u* may also be *NULL* which + causes the contents to be undefined. It is the user's responsibility to fill in + the needed data. The buffer is copied into the new object. If the buffer is not + *NULL*, the return value might be a shared object. Therefore, modification of + the resulting Unicode object is only allowed when *u* is *NULL*. + + .. versionadded:: 3.0 + + +.. cfunction:: PyObject *PyUnicode_FromString(const char *u) + + Create a Unicode object from an UTF-8 encoded null-terminated char buffer + *u*. + + .. versionadded:: 3.0 + + +.. cfunction:: PyObject* PyUnicode_FromFormat(const char *format, ...) + + Take a C :cfunc:`printf`\ -style *format* string and a variable number of + arguments, calculate the size of the resulting Python unicode string and return + a string with the values formatted into it. The variable arguments must be C + types and must correspond exactly to the format characters in the *format* + string. The following format characters are allowed: + + .. % The descriptions for %zd and %zu are wrong, but the truth is complicated + .. % because not all compilers support the %z width modifier -- we fake it + .. % when necessary via interpolating PY_FORMAT_SIZE_T. + + +-------------------+---------------------+--------------------------------+ + | Format Characters | Type | Comment | + +===================+=====================+================================+ + | :attr:`%%` | *n/a* | The literal % character. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%c` | int | A single character, | + | | | represented as an C int. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%d` | int | Exactly equivalent to | + | | | ``printf("%d")``. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%u` | unsigned int | Exactly equivalent to | + | | | ``printf("%u")``. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%ld` | long | Exactly equivalent to | + | | | ``printf("%ld")``. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%lu` | unsigned long | Exactly equivalent to | + | | | ``printf("%lu")``. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%zd` | Py_ssize_t | Exactly equivalent to | + | | | ``printf("%zd")``. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%zu` | size_t | Exactly equivalent to | + | | | ``printf("%zu")``. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%i` | int | Exactly equivalent to | + | | | ``printf("%i")``. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%x` | int | Exactly equivalent to | + | | | ``printf("%x")``. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%s` | char\* | A null-terminated C character | + | | | array. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%p` | void\* | The hex representation of a C | + | | | pointer. Mostly equivalent to | + | | | ``printf("%p")`` except that | + | | | it is guaranteed to start with | + | | | the literal ``0x`` regardless | + | | | of what the platform's | + | | | ``printf`` yields. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%U` | PyObject\* | A unicode object. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%V` | PyObject\*, char \* | A unicode object (which may be | + | | | *NULL*) and a null-terminated | + | | | C character array as a second | + | | | parameter (which will be used, | + | | | if the first parameter is | + | | | *NULL*). | + +-------------------+---------------------+--------------------------------+ + | :attr:`%S` | PyObject\* | The result of calling | + | | | :func:`PyObject_Unicode`. | + +-------------------+---------------------+--------------------------------+ + | :attr:`%R` | PyObject\* | The result of calling | + | | | :func:`PyObject_Repr`. | + +-------------------+---------------------+--------------------------------+ + + An unrecognized format character causes all the rest of the format string to be + copied as-is to the result string, and any extra arguments discarded. + + .. versionadded:: 3.0 + + +.. cfunction:: PyObject* PyUnicode_FromFormatV(const char *format, va_list vargs) + + Identical to :func:`PyUnicode_FromFormat` except that it takes exactly two + arguments. + + .. versionadded:: 3.0 + + +.. cfunction:: Py_UNICODE* PyUnicode_AsUnicode(PyObject *unicode) + + Return a read-only pointer to the Unicode object's internal :ctype:`Py_UNICODE` + buffer, *NULL* if *unicode* is not a Unicode object. + + +.. cfunction:: Py_ssize_t PyUnicode_GetSize(PyObject *unicode) + + Return the length of the Unicode object. + + +.. cfunction:: PyObject* PyUnicode_FromEncodedObject(PyObject *obj, const char *encoding, const char *errors) + + Coerce an encoded object *obj* to an Unicode object and return a reference with + incremented refcount. + + String and other char buffer compatible objects are decoded according to the + given encoding and using the error handling defined by errors. Both can be + *NULL* to have the interface use the default values (see the next section for + details). + + All other objects, including Unicode objects, cause a :exc:`TypeError` to be + set. + + The API returns *NULL* if there was an error. The caller is responsible for + decref'ing the returned objects. + + +.. cfunction:: PyObject* PyUnicode_FromObject(PyObject *obj) + + Shortcut for ``PyUnicode_FromEncodedObject(obj, NULL, "strict")`` which is used + throughout the interpreter whenever coercion to Unicode is needed. + +If the platform supports :ctype:`wchar_t` and provides a header file wchar.h, +Python can interface directly to this type using the following functions. +Support is optimized if Python's own :ctype:`Py_UNICODE` type is identical to +the system's :ctype:`wchar_t`. + +.. % --- wchar_t support for platforms which support it --------------------- + + +.. cfunction:: PyObject* PyUnicode_FromWideChar(const wchar_t *w, Py_ssize_t size) + + Create a Unicode object from the :ctype:`wchar_t` buffer *w* of the given size. + Return *NULL* on failure. + + +.. cfunction:: Py_ssize_t PyUnicode_AsWideChar(PyUnicodeObject *unicode, wchar_t *w, Py_ssize_t size) + + Copy the Unicode object contents into the :ctype:`wchar_t` buffer *w*. At most + *size* :ctype:`wchar_t` characters are copied (excluding a possibly trailing + 0-termination character). Return the number of :ctype:`wchar_t` characters + copied or -1 in case of an error. Note that the resulting :ctype:`wchar_t` + string may or may not be 0-terminated. It is the responsibility of the caller + to make sure that the :ctype:`wchar_t` string is 0-terminated in case this is + required by the application. + + +.. _builtincodecs: + +Built-in Codecs +^^^^^^^^^^^^^^^ + +Python provides a set of builtin codecs which are written in C for speed. All of +these codecs are directly usable via the following functions. + +Many of the following APIs take two arguments encoding and errors. These +parameters encoding and errors have the same semantics as the ones of the +builtin unicode() Unicode object constructor. + +Setting encoding to *NULL* causes the default encoding to be used which is +ASCII. The file system calls should use :cdata:`Py_FileSystemDefaultEncoding` +as the encoding for file names. This variable should be treated as read-only: On +some systems, it will be a pointer to a static string, on others, it will change +at run-time (such as when the application invokes setlocale). + +Error handling is set by errors which may also be set to *NULL* meaning to use +the default handling defined for the codec. Default error handling for all +builtin codecs is "strict" (:exc:`ValueError` is raised). + +The codecs all use a similar interface. Only deviation from the following +generic ones are documented for simplicity. + +These are the generic codec APIs: + +.. % --- Generic Codecs ----------------------------------------------------- + + +.. cfunction:: PyObject* PyUnicode_Decode(const char *s, Py_ssize_t size, const char *encoding, const char *errors) + + Create a Unicode object by decoding *size* bytes of the encoded string *s*. + *encoding* and *errors* have the same meaning as the parameters of the same name + in the :func:`unicode` builtin function. The codec to be used is looked up + using the Python codec registry. Return *NULL* if an exception was raised by + the codec. + + +.. cfunction:: PyObject* PyUnicode_Encode(const Py_UNICODE *s, Py_ssize_t size, const char *encoding, const char *errors) + + Encode the :ctype:`Py_UNICODE` buffer of the given size and return a Python + string object. *encoding* and *errors* have the same meaning as the parameters + of the same name in the Unicode :meth:`encode` method. The codec to be used is + looked up using the Python codec registry. Return *NULL* if an exception was + raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_AsEncodedString(PyObject *unicode, const char *encoding, const char *errors) + + Encode a Unicode object and return the result as Python string object. + *encoding* and *errors* have the same meaning as the parameters of the same name + in the Unicode :meth:`encode` method. The codec to be used is looked up using + the Python codec registry. Return *NULL* if an exception was raised by the + codec. + +These are the UTF-8 codec APIs: + +.. % --- UTF-8 Codecs ------------------------------------------------------- + + +.. cfunction:: PyObject* PyUnicode_DecodeUTF8(const char *s, Py_ssize_t size, const char *errors) + + Create a Unicode object by decoding *size* bytes of the UTF-8 encoded string + *s*. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_DecodeUTF8Stateful(const char *s, Py_ssize_t size, const char *errors, Py_ssize_t *consumed) + + If *consumed* is *NULL*, behave like :cfunc:`PyUnicode_DecodeUTF8`. If + *consumed* is not *NULL*, trailing incomplete UTF-8 byte sequences will not be + treated as an error. Those bytes will not be decoded and the number of bytes + that have been decoded will be stored in *consumed*. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PyUnicode_EncodeUTF8(const Py_UNICODE *s, Py_ssize_t size, const char *errors) + + Encode the :ctype:`Py_UNICODE` buffer of the given size using UTF-8 and return a + Python string object. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_AsUTF8String(PyObject *unicode) + + Encode a Unicode objects using UTF-8 and return the result as Python string + object. Error handling is "strict". Return *NULL* if an exception was raised + by the codec. + +These are the UTF-16 codec APIs: + +.. % --- UTF-16 Codecs ------------------------------------------------------ */ + + +.. cfunction:: PyObject* PyUnicode_DecodeUTF16(const char *s, Py_ssize_t size, const char *errors, int *byteorder) + + Decode *length* bytes from a UTF-16 encoded buffer string and return the + corresponding Unicode object. *errors* (if non-*NULL*) defines the error + handling. It defaults to "strict". + + If *byteorder* is non-*NULL*, the decoder starts decoding using the given byte + order:: + + *byteorder == -1: little endian + *byteorder == 0: native order + *byteorder == 1: big endian + + and then switches if the first two bytes of the input data are a byte order mark + (BOM) and the specified byte order is native order. This BOM is not copied into + the resulting Unicode string. After completion, *\*byteorder* is set to the + current byte order at the. + + If *byteorder* is *NULL*, the codec starts in native order mode. + + Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_DecodeUTF16Stateful(const char *s, Py_ssize_t size, const char *errors, int *byteorder, Py_ssize_t *consumed) + + If *consumed* is *NULL*, behave like :cfunc:`PyUnicode_DecodeUTF16`. If + *consumed* is not *NULL*, :cfunc:`PyUnicode_DecodeUTF16Stateful` will not treat + trailing incomplete UTF-16 byte sequences (such as an odd number of bytes or a + split surrogate pair) as an error. Those bytes will not be decoded and the + number of bytes that have been decoded will be stored in *consumed*. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PyUnicode_EncodeUTF16(const Py_UNICODE *s, Py_ssize_t size, const char *errors, int byteorder) + + Return a Python string object holding the UTF-16 encoded value of the Unicode + data in *s*. If *byteorder* is not ``0``, output is written according to the + following byte order:: + + byteorder == -1: little endian + byteorder == 0: native byte order (writes a BOM mark) + byteorder == 1: big endian + + If byteorder is ``0``, the output string will always start with the Unicode BOM + mark (U+FEFF). In the other two modes, no BOM mark is prepended. + + If *Py_UNICODE_WIDE* is defined, a single :ctype:`Py_UNICODE` value may get + represented as a surrogate pair. If it is not defined, each :ctype:`Py_UNICODE` + values is interpreted as an UCS-2 character. + + Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_AsUTF16String(PyObject *unicode) + + Return a Python string using the UTF-16 encoding in native byte order. The + string always starts with a BOM mark. Error handling is "strict". Return + *NULL* if an exception was raised by the codec. + +These are the "Unicode Escape" codec APIs: + +.. % --- Unicode-Escape Codecs ---------------------------------------------- + + +.. cfunction:: PyObject* PyUnicode_DecodeUnicodeEscape(const char *s, Py_ssize_t size, const char *errors) + + Create a Unicode object by decoding *size* bytes of the Unicode-Escape encoded + string *s*. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_EncodeUnicodeEscape(const Py_UNICODE *s, Py_ssize_t size) + + Encode the :ctype:`Py_UNICODE` buffer of the given size using Unicode-Escape and + return a Python string object. Return *NULL* if an exception was raised by the + codec. + + +.. cfunction:: PyObject* PyUnicode_AsUnicodeEscapeString(PyObject *unicode) + + Encode a Unicode objects using Unicode-Escape and return the result as Python + string object. Error handling is "strict". Return *NULL* if an exception was + raised by the codec. + +These are the "Raw Unicode Escape" codec APIs: + +.. % --- Raw-Unicode-Escape Codecs ------------------------------------------ + + +.. cfunction:: PyObject* PyUnicode_DecodeRawUnicodeEscape(const char *s, Py_ssize_t size, const char *errors) + + Create a Unicode object by decoding *size* bytes of the Raw-Unicode-Escape + encoded string *s*. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_EncodeRawUnicodeEscape(const Py_UNICODE *s, Py_ssize_t size, const char *errors) + + Encode the :ctype:`Py_UNICODE` buffer of the given size using Raw-Unicode-Escape + and return a Python string object. Return *NULL* if an exception was raised by + the codec. + + +.. cfunction:: PyObject* PyUnicode_AsRawUnicodeEscapeString(PyObject *unicode) + + Encode a Unicode objects using Raw-Unicode-Escape and return the result as + Python string object. Error handling is "strict". Return *NULL* if an exception + was raised by the codec. + +These are the Latin-1 codec APIs: Latin-1 corresponds to the first 256 Unicode +ordinals and only these are accepted by the codecs during encoding. + +.. % --- Latin-1 Codecs ----------------------------------------------------- + + +.. cfunction:: PyObject* PyUnicode_DecodeLatin1(const char *s, Py_ssize_t size, const char *errors) + + Create a Unicode object by decoding *size* bytes of the Latin-1 encoded string + *s*. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_EncodeLatin1(const Py_UNICODE *s, Py_ssize_t size, const char *errors) + + Encode the :ctype:`Py_UNICODE` buffer of the given size using Latin-1 and return + a Python string object. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_AsLatin1String(PyObject *unicode) + + Encode a Unicode objects using Latin-1 and return the result as Python string + object. Error handling is "strict". Return *NULL* if an exception was raised + by the codec. + +These are the ASCII codec APIs. Only 7-bit ASCII data is accepted. All other +codes generate errors. + +.. % --- ASCII Codecs ------------------------------------------------------- + + +.. cfunction:: PyObject* PyUnicode_DecodeASCII(const char *s, Py_ssize_t size, const char *errors) + + Create a Unicode object by decoding *size* bytes of the ASCII encoded string + *s*. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_EncodeASCII(const Py_UNICODE *s, Py_ssize_t size, const char *errors) + + Encode the :ctype:`Py_UNICODE` buffer of the given size using ASCII and return a + Python string object. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_AsASCIIString(PyObject *unicode) + + Encode a Unicode objects using ASCII and return the result as Python string + object. Error handling is "strict". Return *NULL* if an exception was raised + by the codec. + +These are the mapping codec APIs: + +.. % --- Character Map Codecs ----------------------------------------------- + +This codec is special in that it can be used to implement many different codecs +(and this is in fact what was done to obtain most of the standard codecs +included in the :mod:`encodings` package). The codec uses mapping to encode and +decode characters. + +Decoding mappings must map single string characters to single Unicode +characters, integers (which are then interpreted as Unicode ordinals) or None +(meaning "undefined mapping" and causing an error). + +Encoding mappings must map single Unicode characters to single string +characters, integers (which are then interpreted as Latin-1 ordinals) or None +(meaning "undefined mapping" and causing an error). + +The mapping objects provided must only support the __getitem__ mapping +interface. + +If a character lookup fails with a LookupError, the character is copied as-is +meaning that its ordinal value will be interpreted as Unicode or Latin-1 ordinal +resp. Because of this, mappings only need to contain those mappings which map +characters to different code points. + + +.. cfunction:: PyObject* PyUnicode_DecodeCharmap(const char *s, Py_ssize_t size, PyObject *mapping, const char *errors) + + Create a Unicode object by decoding *size* bytes of the encoded string *s* using + the given *mapping* object. Return *NULL* if an exception was raised by the + codec. If *mapping* is *NULL* latin-1 decoding will be done. Else it can be a + dictionary mapping byte or a unicode string, which is treated as a lookup table. + Byte values greater that the length of the string and U+FFFE "characters" are + treated as "undefined mapping". + + .. versionchanged:: 2.4 + Allowed unicode string as mapping argument. + + +.. cfunction:: PyObject* PyUnicode_EncodeCharmap(const Py_UNICODE *s, Py_ssize_t size, PyObject *mapping, const char *errors) + + Encode the :ctype:`Py_UNICODE` buffer of the given size using the given + *mapping* object and return a Python string object. Return *NULL* if an + exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_AsCharmapString(PyObject *unicode, PyObject *mapping) + + Encode a Unicode objects using the given *mapping* object and return the result + as Python string object. Error handling is "strict". Return *NULL* if an + exception was raised by the codec. + +The following codec API is special in that maps Unicode to Unicode. + + +.. cfunction:: PyObject* PyUnicode_TranslateCharmap(const Py_UNICODE *s, Py_ssize_t size, PyObject *table, const char *errors) + + Translate a :ctype:`Py_UNICODE` buffer of the given length by applying a + character mapping *table* to it and return the resulting Unicode object. Return + *NULL* when an exception was raised by the codec. + + The *mapping* table must map Unicode ordinal integers to Unicode ordinal + integers or None (causing deletion of the character). + + Mapping tables need only provide the :meth:`__getitem__` interface; dictionaries + and sequences work well. Unmapped character ordinals (ones which cause a + :exc:`LookupError`) are left untouched and are copied as-is. + +These are the MBCS codec APIs. They are currently only available on Windows and +use the Win32 MBCS converters to implement the conversions. Note that MBCS (or +DBCS) is a class of encodings, not just one. The target encoding is defined by +the user settings on the machine running the codec. + +.. % --- MBCS codecs for Windows -------------------------------------------- + + +.. cfunction:: PyObject* PyUnicode_DecodeMBCS(const char *s, Py_ssize_t size, const char *errors) + + Create a Unicode object by decoding *size* bytes of the MBCS encoded string *s*. + Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_DecodeMBCSStateful(const char *s, int size, const char *errors, int *consumed) + + If *consumed* is *NULL*, behave like :cfunc:`PyUnicode_DecodeMBCS`. If + *consumed* is not *NULL*, :cfunc:`PyUnicode_DecodeMBCSStateful` will not decode + trailing lead byte and the number of bytes that have been decoded will be stored + in *consumed*. + + .. versionadded:: 2.5 + + +.. cfunction:: PyObject* PyUnicode_EncodeMBCS(const Py_UNICODE *s, Py_ssize_t size, const char *errors) + + Encode the :ctype:`Py_UNICODE` buffer of the given size using MBCS and return a + Python string object. Return *NULL* if an exception was raised by the codec. + + +.. cfunction:: PyObject* PyUnicode_AsMBCSString(PyObject *unicode) + + Encode a Unicode objects using MBCS and return the result as Python string + object. Error handling is "strict". Return *NULL* if an exception was raised + by the codec. + +.. % --- Methods & Slots ---------------------------------------------------- + + +.. _unicodemethodsandslots: + +Methods and Slot Functions +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The following APIs are capable of handling Unicode objects and strings on input +(we refer to them as strings in the descriptions) and return Unicode objects or +integers as appropriate. + +They all return *NULL* or ``-1`` if an exception occurs. + + +.. cfunction:: PyObject* PyUnicode_Concat(PyObject *left, PyObject *right) + + Concat two strings giving a new Unicode string. + + +.. cfunction:: PyObject* PyUnicode_Split(PyObject *s, PyObject *sep, Py_ssize_t maxsplit) + + Split a string giving a list of Unicode strings. If sep is *NULL*, splitting + will be done at all whitespace substrings. Otherwise, splits occur at the given + separator. At most *maxsplit* splits will be done. If negative, no limit is + set. Separators are not included in the resulting list. + + +.. cfunction:: PyObject* PyUnicode_Splitlines(PyObject *s, int keepend) + + Split a Unicode string at line breaks, returning a list of Unicode strings. + CRLF is considered to be one line break. If *keepend* is 0, the Line break + characters are not included in the resulting strings. + + +.. cfunction:: PyObject* PyUnicode_Translate(PyObject *str, PyObject *table, const char *errors) + + Translate a string by applying a character mapping table to it and return the + resulting Unicode object. + + The mapping table must map Unicode ordinal integers to Unicode ordinal integers + or None (causing deletion of the character). + + Mapping tables need only provide the :meth:`__getitem__` interface; dictionaries + and sequences work well. Unmapped character ordinals (ones which cause a + :exc:`LookupError`) are left untouched and are copied as-is. + + *errors* has the usual meaning for codecs. It may be *NULL* which indicates to + use the default error handling. + + +.. cfunction:: PyObject* PyUnicode_Join(PyObject *separator, PyObject *seq) + + Join a sequence of strings using the given separator and return the resulting + Unicode string. + + +.. cfunction:: int PyUnicode_Tailmatch(PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end, int direction) + + Return 1 if *substr* matches *str*[*start*:*end*] at the given tail end + (*direction* == -1 means to do a prefix match, *direction* == 1 a suffix match), + 0 otherwise. Return ``-1`` if an error occurred. + + +.. cfunction:: Py_ssize_t PyUnicode_Find(PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end, int direction) + + Return the first position of *substr* in *str*[*start*:*end*] using the given + *direction* (*direction* == 1 means to do a forward search, *direction* == -1 a + backward search). The return value is the index of the first match; a value of + ``-1`` indicates that no match was found, and ``-2`` indicates that an error + occurred and an exception has been set. + + +.. cfunction:: Py_ssize_t PyUnicode_Count(PyObject *str, PyObject *substr, Py_ssize_t start, Py_ssize_t end) + + Return the number of non-overlapping occurrences of *substr* in + ``str[start:end]``. Return ``-1`` if an error occurred. + + +.. cfunction:: PyObject* PyUnicode_Replace(PyObject *str, PyObject *substr, PyObject *replstr, Py_ssize_t maxcount) + + Replace at most *maxcount* occurrences of *substr* in *str* with *replstr* and + return the resulting Unicode object. *maxcount* == -1 means replace all + occurrences. + + +.. cfunction:: int PyUnicode_Compare(PyObject *left, PyObject *right) + + Compare two strings and return -1, 0, 1 for less than, equal, and greater than, + respectively. + + +.. cfunction:: int PyUnicode_RichCompare(PyObject *left, PyObject *right, int op) + + Rich compare two unicode strings and return one of the following: + + * ``NULL`` in case an exception was raised + * :const:`Py_True` or :const:`Py_False` for successful comparisons + * :const:`Py_NotImplemented` in case the type combination is unknown + + Note that :const:`Py_EQ` and :const:`Py_NE` comparisons can cause a + :exc:`UnicodeWarning` in case the conversion of the arguments to Unicode fails + with a :exc:`UnicodeDecodeError`. + + Possible values for *op* are :const:`Py_GT`, :const:`Py_GE`, :const:`Py_EQ`, + :const:`Py_NE`, :const:`Py_LT`, and :const:`Py_LE`. + + +.. cfunction:: PyObject* PyUnicode_Format(PyObject *format, PyObject *args) + + Return a new string object from *format* and *args*; this is analogous to + ``format % args``. The *args* argument must be a tuple. + + +.. cfunction:: int PyUnicode_Contains(PyObject *container, PyObject *element) + + Check whether *element* is contained in *container* and return true or false + accordingly. + + *element* has to coerce to a one element Unicode string. ``-1`` is returned if + there was an error. + + +.. cfunction:: void PyUnicode_InternInPlace(PyObject **string) + + Intern the argument *\*string* in place. The argument must be the address of a + pointer variable pointing to a Python unicode string object. If there is an + existing interned string that is the same as *\*string*, it sets *\*string* to + it (decrementing the reference count of the old string object and incrementing + the reference count of the interned string object), otherwise it leaves + *\*string* alone and interns it (incrementing its reference count). + (Clarification: even though there is a lot of talk about reference counts, think + of this function as reference-count-neutral; you own the object after the call + if and only if you owned it before the call.) + + +.. cfunction:: PyObject* PyUnicode_InternFromString(const char *v) + + A combination of :cfunc:`PyUnicode_FromString` and + :cfunc:`PyUnicode_InternInPlace`, returning either a new unicode string object + that has been interned, or a new ("owned") reference to an earlier interned + string object with the same value. + + +.. _bufferobjects: + +Buffer Objects +-------------- + +.. sectionauthor:: Greg Stein + + +.. index:: + object: buffer + single: buffer interface + +Python objects implemented in C can export a group of functions called the +"buffer interface." These functions can be used by an object to expose its data +in a raw, byte-oriented format. Clients of the object can use the buffer +interface to access the object data directly, without needing to copy it first. + +Two examples of objects that support the buffer interface are strings and +arrays. The string object exposes the character contents in the buffer +interface's byte-oriented form. An array can also expose its contents, but it +should be noted that array elements may be multi-byte values. + +An example user of the buffer interface is the file object's :meth:`write` +method. Any object that can export a series of bytes through the buffer +interface can be written to a file. There are a number of format codes to +:cfunc:`PyArg_ParseTuple` that operate against an object's buffer interface, +returning data from the target object. + +.. index:: single: PyBufferProcs + +More information on the buffer interface is provided in the section +:ref:`buffer-structs`, under the description for :ctype:`PyBufferProcs`. + +A "buffer object" is defined in the :file:`bufferobject.h` header (included by +:file:`Python.h`). These objects look very similar to string objects at the +Python programming level: they support slicing, indexing, concatenation, and +some other standard string operations. However, their data can come from one of +two sources: from a block of memory, or from another object which exports the +buffer interface. + +Buffer objects are useful as a way to expose the data from another object's +buffer interface to the Python programmer. They can also be used as a zero-copy +slicing mechanism. Using their ability to reference a block of memory, it is +possible to expose any data to the Python programmer quite easily. The memory +could be a large, constant array in a C extension, it could be a raw block of +memory for manipulation before passing to an operating system library, or it +could be used to pass around structured data in its native, in-memory format. + + +.. ctype:: PyBufferObject + + This subtype of :ctype:`PyObject` represents a buffer object. + + +.. cvar:: PyTypeObject PyBuffer_Type + + .. index:: single: BufferType (in module types) + + The instance of :ctype:`PyTypeObject` which represents the Python buffer type; + it is the same object as ``buffer`` and ``types.BufferType`` in the Python + layer. . + + +.. cvar:: int Py_END_OF_BUFFER + + This constant may be passed as the *size* parameter to + :cfunc:`PyBuffer_FromObject` or :cfunc:`PyBuffer_FromReadWriteObject`. It + indicates that the new :ctype:`PyBufferObject` should refer to *base* object + from the specified *offset* to the end of its exported buffer. Using this + enables the caller to avoid querying the *base* object for its length. + + +.. cfunction:: int PyBuffer_Check(PyObject *p) + + Return true if the argument has type :cdata:`PyBuffer_Type`. + + +.. cfunction:: PyObject* PyBuffer_FromObject(PyObject *base, Py_ssize_t offset, Py_ssize_t size) + + Return a new read-only buffer object. This raises :exc:`TypeError` if *base* + doesn't support the read-only buffer protocol or doesn't provide exactly one + buffer segment, or it raises :exc:`ValueError` if *offset* is less than zero. + The buffer will hold a reference to the *base* object, and the buffer's contents + will refer to the *base* object's buffer interface, starting as position + *offset* and extending for *size* bytes. If *size* is :const:`Py_END_OF_BUFFER`, + then the new buffer's contents extend to the length of the *base* object's + exported buffer data. + + +.. cfunction:: PyObject* PyBuffer_FromReadWriteObject(PyObject *base, Py_ssize_t offset, Py_ssize_t size) + + Return a new writable buffer object. Parameters and exceptions are similar to + those for :cfunc:`PyBuffer_FromObject`. If the *base* object does not export + the writeable buffer protocol, then :exc:`TypeError` is raised. + + +.. cfunction:: PyObject* PyBuffer_FromMemory(void *ptr, Py_ssize_t size) + + Return a new read-only buffer object that reads from a specified location in + memory, with a specified size. The caller is responsible for ensuring that the + memory buffer, passed in as *ptr*, is not deallocated while the returned buffer + object exists. Raises :exc:`ValueError` if *size* is less than zero. Note that + :const:`Py_END_OF_BUFFER` may *not* be passed for the *size* parameter; + :exc:`ValueError` will be raised in that case. + + +.. cfunction:: PyObject* PyBuffer_FromReadWriteMemory(void *ptr, Py_ssize_t size) + + Similar to :cfunc:`PyBuffer_FromMemory`, but the returned buffer is writable. + + +.. cfunction:: PyObject* PyBuffer_New(Py_ssize_t size) + + Return a new writable buffer object that maintains its own memory buffer of + *size* bytes. :exc:`ValueError` is returned if *size* is not zero or positive. + Note that the memory buffer (as returned by :cfunc:`PyObject_AsWriteBuffer`) is + not specifically aligned. + + +.. _tupleobjects: + +Tuple Objects +------------- + +.. index:: object: tuple + + +.. ctype:: PyTupleObject + + This subtype of :ctype:`PyObject` represents a Python tuple object. + + +.. cvar:: PyTypeObject PyTuple_Type + + .. index:: single: TupleType (in module types) + + This instance of :ctype:`PyTypeObject` represents the Python tuple type; it is + the same object as ``tuple`` and ``types.TupleType`` in the Python layer.. + + +.. cfunction:: int PyTuple_Check(PyObject *p) + + Return true if *p* is a tuple object or an instance of a subtype of the tuple + type. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyTuple_CheckExact(PyObject *p) + + Return true if *p* is a tuple object, but not an instance of a subtype of the + tuple type. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyTuple_New(Py_ssize_t len) + + Return a new tuple object of size *len*, or *NULL* on failure. + + +.. cfunction:: PyObject* PyTuple_Pack(Py_ssize_t n, ...) + + Return a new tuple object of size *n*, or *NULL* on failure. The tuple values + are initialized to the subsequent *n* C arguments pointing to Python objects. + ``PyTuple_Pack(2, a, b)`` is equivalent to ``Py_BuildValue("(OO)", a, b)``. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyTuple_Size(PyObject *p) + + Take a pointer to a tuple object, and return the size of that tuple. + + +.. cfunction:: int PyTuple_GET_SIZE(PyObject *p) + + Return the size of the tuple *p*, which must be non-*NULL* and point to a tuple; + no error checking is performed. + + +.. cfunction:: PyObject* PyTuple_GetItem(PyObject *p, Py_ssize_t pos) + + Return the object at position *pos* in the tuple pointed to by *p*. If *pos* is + out of bounds, return *NULL* and sets an :exc:`IndexError` exception. + + +.. cfunction:: PyObject* PyTuple_GET_ITEM(PyObject *p, Py_ssize_t pos) + + Like :cfunc:`PyTuple_GetItem`, but does no checking of its arguments. + + +.. cfunction:: PyObject* PyTuple_GetSlice(PyObject *p, Py_ssize_t low, Py_ssize_t high) + + Take a slice of the tuple pointed to by *p* from *low* to *high* and return it + as a new tuple. + + +.. cfunction:: int PyTuple_SetItem(PyObject *p, Py_ssize_t pos, PyObject *o) + + Insert a reference to object *o* at position *pos* of the tuple pointed to by + *p*. Return ``0`` on success. + + .. note:: + + This function "steals" a reference to *o*. + + +.. cfunction:: void PyTuple_SET_ITEM(PyObject *p, Py_ssize_t pos, PyObject *o) + + Like :cfunc:`PyTuple_SetItem`, but does no error checking, and should *only* be + used to fill in brand new tuples. + + .. note:: + + This function "steals" a reference to *o*. + + +.. cfunction:: int _PyTuple_Resize(PyObject **p, Py_ssize_t newsize) + + Can be used to resize a tuple. *newsize* will be the new length of the tuple. + Because tuples are *supposed* to be immutable, this should only be used if there + is only one reference to the object. Do *not* use this if the tuple may already + be known to some other part of the code. The tuple will always grow or shrink + at the end. Think of this as destroying the old tuple and creating a new one, + only more efficiently. Returns ``0`` on success. Client code should never + assume that the resulting value of ``*p`` will be the same as before calling + this function. If the object referenced by ``*p`` is replaced, the original + ``*p`` is destroyed. On failure, returns ``-1`` and sets ``*p`` to *NULL*, and + raises :exc:`MemoryError` or :exc:`SystemError`. + + .. versionchanged:: 2.2 + Removed unused third parameter, *last_is_sticky*. + + +.. _listobjects: + +List Objects +------------ + +.. index:: object: list + + +.. ctype:: PyListObject + + This subtype of :ctype:`PyObject` represents a Python list object. + + +.. cvar:: PyTypeObject PyList_Type + + .. index:: single: ListType (in module types) + + This instance of :ctype:`PyTypeObject` represents the Python list type. This is + the same object as ``list`` and ``types.ListType`` in the Python layer. + + +.. cfunction:: int PyList_Check(PyObject *p) + + Return true if *p* is a list object or an instance of a subtype of the list + type. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyList_CheckExact(PyObject *p) + + Return true if *p* is a list object, but not an instance of a subtype of the + list type. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyList_New(Py_ssize_t len) + + Return a new list of length *len* on success, or *NULL* on failure. + + .. note:: + + If *length* is greater than zero, the returned list object's items are set to + ``NULL``. Thus you cannot use abstract API functions such as + :cfunc:`PySequence_SetItem` or expose the object to Python code before setting + all items to a real object with :cfunc:`PyList_SetItem`. + + +.. cfunction:: Py_ssize_t PyList_Size(PyObject *list) + + .. index:: builtin: len + + Return the length of the list object in *list*; this is equivalent to + ``len(list)`` on a list object. + + +.. cfunction:: Py_ssize_t PyList_GET_SIZE(PyObject *list) + + Macro form of :cfunc:`PyList_Size` without error checking. + + +.. cfunction:: PyObject* PyList_GetItem(PyObject *list, Py_ssize_t index) + + Return the object at position *pos* in the list pointed to by *p*. The position + must be positive, indexing from the end of the list is not supported. If *pos* + is out of bounds, return *NULL* and set an :exc:`IndexError` exception. + + +.. cfunction:: PyObject* PyList_GET_ITEM(PyObject *list, Py_ssize_t i) + + Macro form of :cfunc:`PyList_GetItem` without error checking. + + +.. cfunction:: int PyList_SetItem(PyObject *list, Py_ssize_t index, PyObject *item) + + Set the item at index *index* in list to *item*. Return ``0`` on success or + ``-1`` on failure. + + .. note:: + + This function "steals" a reference to *item* and discards a reference to an item + already in the list at the affected position. + + +.. cfunction:: void PyList_SET_ITEM(PyObject *list, Py_ssize_t i, PyObject *o) + + Macro form of :cfunc:`PyList_SetItem` without error checking. This is normally + only used to fill in new lists where there is no previous content. + + .. note:: + + This function "steals" a reference to *item*, and, unlike + :cfunc:`PyList_SetItem`, does *not* discard a reference to any item that it + being replaced; any reference in *list* at position *i* will be leaked. + + +.. cfunction:: int PyList_Insert(PyObject *list, Py_ssize_t index, PyObject *item) + + Insert the item *item* into list *list* in front of index *index*. Return ``0`` + if successful; return ``-1`` and set an exception if unsuccessful. Analogous to + ``list.insert(index, item)``. + + +.. cfunction:: int PyList_Append(PyObject *list, PyObject *item) + + Append the object *item* at the end of list *list*. Return ``0`` if successful; + return ``-1`` and set an exception if unsuccessful. Analogous to + ``list.append(item)``. + + +.. cfunction:: PyObject* PyList_GetSlice(PyObject *list, Py_ssize_t low, Py_ssize_t high) + + Return a list of the objects in *list* containing the objects *between* *low* + and *high*. Return *NULL* and set an exception if unsuccessful. Analogous to + ``list[low:high]``. + + +.. cfunction:: int PyList_SetSlice(PyObject *list, Py_ssize_t low, Py_ssize_t high, PyObject *itemlist) + + Set the slice of *list* between *low* and *high* to the contents of *itemlist*. + Analogous to ``list[low:high] = itemlist``. The *itemlist* may be *NULL*, + indicating the assignment of an empty list (slice deletion). Return ``0`` on + success, ``-1`` on failure. + + +.. cfunction:: int PyList_Sort(PyObject *list) + + Sort the items of *list* in place. Return ``0`` on success, ``-1`` on failure. + This is equivalent to ``list.sort()``. + + +.. cfunction:: int PyList_Reverse(PyObject *list) + + Reverse the items of *list* in place. Return ``0`` on success, ``-1`` on + failure. This is the equivalent of ``list.reverse()``. + + +.. cfunction:: PyObject* PyList_AsTuple(PyObject *list) + + .. index:: builtin: tuple + + Return a new tuple object containing the contents of *list*; equivalent to + ``tuple(list)``. + + +.. _mapobjects: + +Mapping Objects +=============== + +.. index:: object: mapping + + +.. _dictobjects: + +Dictionary Objects +------------------ + +.. index:: object: dictionary + + +.. ctype:: PyDictObject + + This subtype of :ctype:`PyObject` represents a Python dictionary object. + + +.. cvar:: PyTypeObject PyDict_Type + + .. index:: + single: DictType (in module types) + single: DictionaryType (in module types) + + This instance of :ctype:`PyTypeObject` represents the Python dictionary type. + This is exposed to Python programs as ``dict`` and ``types.DictType``. + + +.. cfunction:: int PyDict_Check(PyObject *p) + + Return true if *p* is a dict object or an instance of a subtype of the dict + type. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyDict_CheckExact(PyObject *p) + + Return true if *p* is a dict object, but not an instance of a subtype of the + dict type. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PyDict_New() + + Return a new empty dictionary, or *NULL* on failure. + + +.. cfunction:: PyObject* PyDictProxy_New(PyObject *dict) + + Return a proxy object for a mapping which enforces read-only behavior. This is + normally used to create a proxy to prevent modification of the dictionary for + non-dynamic class types. + + .. versionadded:: 2.2 + + +.. cfunction:: void PyDict_Clear(PyObject *p) + + Empty an existing dictionary of all key-value pairs. + + +.. cfunction:: int PyDict_Contains(PyObject *p, PyObject *key) + + Determine if dictionary *p* contains *key*. If an item in *p* is matches *key*, + return ``1``, otherwise return ``0``. On error, return ``-1``. This is + equivalent to the Python expression ``key in p``. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PyDict_Copy(PyObject *p) + + Return a new dictionary that contains the same key-value pairs as *p*. + + .. versionadded:: 1.6 + + +.. cfunction:: int PyDict_SetItem(PyObject *p, PyObject *key, PyObject *val) + + Insert *value* into the dictionary *p* with a key of *key*. *key* must be + hashable; if it isn't, :exc:`TypeError` will be raised. Return ``0`` on success + or ``-1`` on failure. + + +.. cfunction:: int PyDict_SetItemString(PyObject *p, const char *key, PyObject *val) + + .. index:: single: PyString_FromString() + + Insert *value* into the dictionary *p* using *key* as a key. *key* should be a + :ctype:`char\*`. The key object is created using ``PyString_FromString(key)``. + Return ``0`` on success or ``-1`` on failure. + + +.. cfunction:: int PyDict_DelItem(PyObject *p, PyObject *key) + + Remove the entry in dictionary *p* with key *key*. *key* must be hashable; if it + isn't, :exc:`TypeError` is raised. Return ``0`` on success or ``-1`` on + failure. + + +.. cfunction:: int PyDict_DelItemString(PyObject *p, char *key) + + Remove the entry in dictionary *p* which has a key specified by the string + *key*. Return ``0`` on success or ``-1`` on failure. + + +.. cfunction:: PyObject* PyDict_GetItem(PyObject *p, PyObject *key) + + Return the object from dictionary *p* which has a key *key*. Return *NULL* if + the key *key* is not present, but *without* setting an exception. + + +.. cfunction:: PyObject* PyDict_GetItemString(PyObject *p, const char *key) + + This is the same as :cfunc:`PyDict_GetItem`, but *key* is specified as a + :ctype:`char\*`, rather than a :ctype:`PyObject\*`. + + +.. cfunction:: PyObject* PyDict_Items(PyObject *p) + + Return a :ctype:`PyListObject` containing all the items from the dictionary, as + in the dictionary method :meth:`dict.items`. + + +.. cfunction:: PyObject* PyDict_Keys(PyObject *p) + + Return a :ctype:`PyListObject` containing all the keys from the dictionary, as + in the dictionary method :meth:`dict.keys`. + + +.. cfunction:: PyObject* PyDict_Values(PyObject *p) + + Return a :ctype:`PyListObject` containing all the values from the dictionary + *p*, as in the dictionary method :meth:`dict.values`. + + +.. cfunction:: Py_ssize_t PyDict_Size(PyObject *p) + + .. index:: builtin: len + + Return the number of items in the dictionary. This is equivalent to ``len(p)`` + on a dictionary. + + +.. cfunction:: int PyDict_Next(PyObject *p, Py_ssize_t *ppos, PyObject **pkey, PyObject **pvalue) + + Iterate over all key-value pairs in the dictionary *p*. The :ctype:`int` + referred to by *ppos* must be initialized to ``0`` prior to the first call to + this function to start the iteration; the function returns true for each pair in + the dictionary, and false once all pairs have been reported. The parameters + *pkey* and *pvalue* should either point to :ctype:`PyObject\*` variables that + will be filled in with each key and value, respectively, or may be *NULL*. Any + references returned through them are borrowed. *ppos* should not be altered + during iteration. Its value represents offsets within the internal dictionary + structure, and since the structure is sparse, the offsets are not consecutive. + + For example:: + + PyObject *key, *value; + Py_ssize_t pos = 0; + + while (PyDict_Next(self->dict, &pos, &key, &value)) { + /* do something interesting with the values... */ + ... + } + + The dictionary *p* should not be mutated during iteration. It is safe (since + Python 2.1) to modify the values of the keys as you iterate over the dictionary, + but only so long as the set of keys does not change. For example:: + + PyObject *key, *value; + Py_ssize_t pos = 0; + + while (PyDict_Next(self->dict, &pos, &key, &value)) { + int i = PyInt_AS_LONG(value) + 1; + PyObject *o = PyInt_FromLong(i); + if (o == NULL) + return -1; + if (PyDict_SetItem(self->dict, key, o) < 0) { + Py_DECREF(o); + return -1; + } + Py_DECREF(o); + } + + +.. cfunction:: int PyDict_Merge(PyObject *a, PyObject *b, int override) + + Iterate over mapping object *b* adding key-value pairs to dictionary *a*. *b* + may be a dictionary, or any object supporting :func:`PyMapping_Keys` and + :func:`PyObject_GetItem`. If *override* is true, existing pairs in *a* will be + replaced if a matching key is found in *b*, otherwise pairs will only be added + if there is not a matching key in *a*. Return ``0`` on success or ``-1`` if an + exception was raised. + + .. versionadded:: 2.2 + + +.. cfunction:: int PyDict_Update(PyObject *a, PyObject *b) + + This is the same as ``PyDict_Merge(a, b, 1)`` in C, or ``a.update(b)`` in + Python. Return ``0`` on success or ``-1`` if an exception was raised. + + .. versionadded:: 2.2 + + +.. cfunction:: int PyDict_MergeFromSeq2(PyObject *a, PyObject *seq2, int override) + + Update or merge into dictionary *a*, from the key-value pairs in *seq2*. *seq2* + must be an iterable object producing iterable objects of length 2, viewed as + key-value pairs. In case of duplicate keys, the last wins if *override* is + true, else the first wins. Return ``0`` on success or ``-1`` if an exception was + raised. Equivalent Python (except for the return value):: + + def PyDict_MergeFromSeq2(a, seq2, override): + for key, value in seq2: + if override or key not in a: + a[key] = value + + .. versionadded:: 2.2 + + +.. _otherobjects: + +Other Objects +============= + + +.. _classobjects: + +Class Objects +------------- + +.. index:: object: class + +Note that the class objects described here represent old-style classes, which +will go away in Python 3. When creating new types for extension modules, you +will want to work with type objects (section :ref:`typeobjects`). + + +.. ctype:: PyClassObject + + The C structure of the objects used to describe built-in classes. + + +.. cvar:: PyObject* PyClass_Type + + .. index:: single: ClassType (in module types) + + This is the type object for class objects; it is the same object as + ``types.ClassType`` in the Python layer. + + +.. cfunction:: int PyClass_Check(PyObject *o) + + Return true if the object *o* is a class object, including instances of types + derived from the standard class object. Return false in all other cases. + + +.. cfunction:: int PyClass_IsSubclass(PyObject *klass, PyObject *base) + + Return true if *klass* is a subclass of *base*. Return false in all other cases. + + +.. _fileobjects: + +File Objects +------------ + +.. index:: object: file + +Python's built-in file objects are implemented entirely on the :ctype:`FILE\*` +support from the C standard library. This is an implementation detail and may +change in future releases of Python. + + +.. ctype:: PyFileObject + + This subtype of :ctype:`PyObject` represents a Python file object. + + +.. cvar:: PyTypeObject PyFile_Type + + .. index:: single: FileType (in module types) + + This instance of :ctype:`PyTypeObject` represents the Python file type. This is + exposed to Python programs as ``file`` and ``types.FileType``. + + +.. cfunction:: int PyFile_Check(PyObject *p) + + Return true if its argument is a :ctype:`PyFileObject` or a subtype of + :ctype:`PyFileObject`. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyFile_CheckExact(PyObject *p) + + Return true if its argument is a :ctype:`PyFileObject`, but not a subtype of + :ctype:`PyFileObject`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyFile_FromString(char *filename, char *mode) + + .. index:: single: fopen() + + On success, return a new file object that is opened on the file given by + *filename*, with a file mode given by *mode*, where *mode* has the same + semantics as the standard C routine :cfunc:`fopen`. On failure, return *NULL*. + + +.. cfunction:: PyObject* PyFile_FromFile(FILE *fp, char *name, char *mode, int (*close)(FILE*)) + + Create a new :ctype:`PyFileObject` from the already-open standard C file + pointer, *fp*. The function *close* will be called when the file should be + closed. Return *NULL* on failure. + + +.. cfunction:: FILE* PyFile_AsFile(PyObject *p) + + Return the file object associated with *p* as a :ctype:`FILE\*`. + + +.. cfunction:: PyObject* PyFile_GetLine(PyObject *p, int n) + + .. index:: single: EOFError (built-in exception) + + Equivalent to ``p.readline([n])``, this function reads one line from the + object *p*. *p* may be a file object or any object with a :meth:`readline` + method. If *n* is ``0``, exactly one line is read, regardless of the length of + the line. If *n* is greater than ``0``, no more than *n* bytes will be read + from the file; a partial line can be returned. In both cases, an empty string + is returned if the end of the file is reached immediately. If *n* is less than + ``0``, however, one line is read regardless of length, but :exc:`EOFError` is + raised if the end of the file is reached immediately. + + +.. cfunction:: PyObject* PyFile_Name(PyObject *p) + + Return the name of the file specified by *p* as a string object. + + +.. cfunction:: void PyFile_SetBufSize(PyFileObject *p, int n) + + .. index:: single: setvbuf() + + Available on systems with :cfunc:`setvbuf` only. This should only be called + immediately after file object creation. + + +.. cfunction:: int PyFile_Encoding(PyFileObject *p, char *enc) + + Set the file's encoding for Unicode output to *enc*. Return 1 on success and 0 + on failure. + + .. versionadded:: 2.3 + + +.. cfunction:: int PyFile_SoftSpace(PyObject *p, int newflag) + + .. index:: single: softspace (file attribute) + + This function exists for internal use by the interpreter. Set the + :attr:`softspace` attribute of *p* to *newflag* and return the previous value. + *p* does not have to be a file object for this function to work properly; any + object is supported (thought its only interesting if the :attr:`softspace` + attribute can be set). This function clears any errors, and will return ``0`` + as the previous value if the attribute either does not exist or if there were + errors in retrieving it. There is no way to detect errors from this function, + but doing so should not be needed. + + +.. cfunction:: int PyFile_WriteObject(PyObject *obj, PyObject *p, int flags) + + .. index:: single: Py_PRINT_RAW + + Write object *obj* to file object *p*. The only supported flag for *flags* is + :const:`Py_PRINT_RAW`; if given, the :func:`str` of the object is written + instead of the :func:`repr`. Return ``0`` on success or ``-1`` on failure; the + appropriate exception will be set. + + +.. cfunction:: int PyFile_WriteString(const char *s, PyObject *p) + + Write string *s* to file object *p*. Return ``0`` on success or ``-1`` on + failure; the appropriate exception will be set. + + +.. _instanceobjects: + +Instance Objects +---------------- + +.. index:: object: instance + +There are very few functions specific to instance objects. + + +.. cvar:: PyTypeObject PyInstance_Type + + Type object for class instances. + + +.. cfunction:: int PyInstance_Check(PyObject *obj) + + Return true if *obj* is an instance. + + +.. cfunction:: PyObject* PyInstance_New(PyObject *class, PyObject *arg, PyObject *kw) + + Create a new instance of a specific class. The parameters *arg* and *kw* are + used as the positional and keyword parameters to the object's constructor. + + +.. cfunction:: PyObject* PyInstance_NewRaw(PyObject *class, PyObject *dict) + + Create a new instance of a specific class without calling its constructor. + *class* is the class of new object. The *dict* parameter will be used as the + object's :attr:`__dict__`; if *NULL*, a new dictionary will be created for the + instance. + + +.. _function-objects: + +Function Objects +---------------- + +.. index:: object: function + +There are a few functions specific to Python functions. + + +.. ctype:: PyFunctionObject + + The C structure used for functions. + + +.. cvar:: PyTypeObject PyFunction_Type + + .. index:: single: MethodType (in module types) + + This is an instance of :ctype:`PyTypeObject` and represents the Python function + type. It is exposed to Python programmers as ``types.FunctionType``. + + +.. cfunction:: int PyFunction_Check(PyObject *o) + + Return true if *o* is a function object (has type :cdata:`PyFunction_Type`). + The parameter must not be *NULL*. + + +.. cfunction:: PyObject* PyFunction_New(PyObject *code, PyObject *globals) + + Return a new function object associated with the code object *code*. *globals* + must be a dictionary with the global variables accessible to the function. + + The function's docstring, name and *__module__* are retrieved from the code + object, the argument defaults and closure are set to *NULL*. + + +.. cfunction:: PyObject* PyFunction_GetCode(PyObject *op) + + Return the code object associated with the function object *op*. + + +.. cfunction:: PyObject* PyFunction_GetGlobals(PyObject *op) + + Return the globals dictionary associated with the function object *op*. + + +.. cfunction:: PyObject* PyFunction_GetModule(PyObject *op) + + Return the *__module__* attribute of the function object *op*. This is normally + a string containing the module name, but can be set to any other object by + Python code. + + +.. cfunction:: PyObject* PyFunction_GetDefaults(PyObject *op) + + Return the argument default values of the function object *op*. This can be a + tuple of arguments or *NULL*. + + +.. cfunction:: int PyFunction_SetDefaults(PyObject *op, PyObject *defaults) + + Set the argument default values for the function object *op*. *defaults* must be + *Py_None* or a tuple. + + Raises :exc:`SystemError` and returns ``-1`` on failure. + + +.. cfunction:: PyObject* PyFunction_GetClosure(PyObject *op) + + Return the closure associated with the function object *op*. This can be *NULL* + or a tuple of cell objects. + + +.. cfunction:: int PyFunction_SetClosure(PyObject *op, PyObject *closure) + + Set the closure associated with the function object *op*. *closure* must be + *Py_None* or a tuple of cell objects. + + Raises :exc:`SystemError` and returns ``-1`` on failure. + + +.. _method-objects: + +Method Objects +-------------- + +.. index:: object: method + +There are some useful functions that are useful for working with method objects. + + +.. cvar:: PyTypeObject PyMethod_Type + + .. index:: single: MethodType (in module types) + + This instance of :ctype:`PyTypeObject` represents the Python method type. This + is exposed to Python programs as ``types.MethodType``. + + +.. cfunction:: int PyMethod_Check(PyObject *o) + + Return true if *o* is a method object (has type :cdata:`PyMethod_Type`). The + parameter must not be *NULL*. + + +.. cfunction:: PyObject* PyMethod_New(PyObject *func, PyObject *self, PyObject *class) + + Return a new method object, with *func* being any callable object; this is the + function that will be called when the method is called. If this method should + be bound to an instance, *self* should be the instance and *class* should be the + class of *self*, otherwise *self* should be *NULL* and *class* should be the + class which provides the unbound method.. + + +.. cfunction:: PyObject* PyMethod_Class(PyObject *meth) + + Return the class object from which the method *meth* was created; if this was + created from an instance, it will be the class of the instance. + + +.. cfunction:: PyObject* PyMethod_GET_CLASS(PyObject *meth) + + Macro version of :cfunc:`PyMethod_Class` which avoids error checking. + + +.. cfunction:: PyObject* PyMethod_Function(PyObject *meth) + + Return the function object associated with the method *meth*. + + +.. cfunction:: PyObject* PyMethod_GET_FUNCTION(PyObject *meth) + + Macro version of :cfunc:`PyMethod_Function` which avoids error checking. + + +.. cfunction:: PyObject* PyMethod_Self(PyObject *meth) + + Return the instance associated with the method *meth* if it is bound, otherwise + return *NULL*. + + +.. cfunction:: PyObject* PyMethod_GET_SELF(PyObject *meth) + + Macro version of :cfunc:`PyMethod_Self` which avoids error checking. + + +.. _moduleobjects: + +Module Objects +-------------- + +.. index:: object: module + +There are only a few functions special to module objects. + + +.. cvar:: PyTypeObject PyModule_Type + + .. index:: single: ModuleType (in module types) + + This instance of :ctype:`PyTypeObject` represents the Python module type. This + is exposed to Python programs as ``types.ModuleType``. + + +.. cfunction:: int PyModule_Check(PyObject *p) + + Return true if *p* is a module object, or a subtype of a module object. + + .. versionchanged:: 2.2 + Allowed subtypes to be accepted. + + +.. cfunction:: int PyModule_CheckExact(PyObject *p) + + Return true if *p* is a module object, but not a subtype of + :cdata:`PyModule_Type`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyModule_New(const char *name) + + .. index:: + single: __name__ (module attribute) + single: __doc__ (module attribute) + single: __file__ (module attribute) + + Return a new module object with the :attr:`__name__` attribute set to *name*. + Only the module's :attr:`__doc__` and :attr:`__name__` attributes are filled in; + the caller is responsible for providing a :attr:`__file__` attribute. + + +.. cfunction:: PyObject* PyModule_GetDict(PyObject *module) + + .. index:: single: __dict__ (module attribute) + + Return the dictionary object that implements *module*'s namespace; this object + is the same as the :attr:`__dict__` attribute of the module object. This + function never fails. It is recommended extensions use other + :cfunc:`PyModule_\*` and :cfunc:`PyObject_\*` functions rather than directly + manipulate a module's :attr:`__dict__`. + + +.. cfunction:: char* PyModule_GetName(PyObject *module) + + .. index:: + single: __name__ (module attribute) + single: SystemError (built-in exception) + + Return *module*'s :attr:`__name__` value. If the module does not provide one, + or if it is not a string, :exc:`SystemError` is raised and *NULL* is returned. + + +.. cfunction:: char* PyModule_GetFilename(PyObject *module) + + .. index:: + single: __file__ (module attribute) + single: SystemError (built-in exception) + + Return the name of the file from which *module* was loaded using *module*'s + :attr:`__file__` attribute. If this is not defined, or if it is not a string, + raise :exc:`SystemError` and return *NULL*. + + +.. cfunction:: int PyModule_AddObject(PyObject *module, const char *name, PyObject *value) + + Add an object to *module* as *name*. This is a convenience function which can + be used from the module's initialization function. This steals a reference to + *value*. Return ``-1`` on error, ``0`` on success. + + .. versionadded:: 2.0 + + +.. cfunction:: int PyModule_AddIntConstant(PyObject *module, const char *name, long value) + + Add an integer constant to *module* as *name*. This convenience function can be + used from the module's initialization function. Return ``-1`` on error, ``0`` on + success. + + .. versionadded:: 2.0 + + +.. cfunction:: int PyModule_AddStringConstant(PyObject *module, const char *name, const char *value) + + Add a string constant to *module* as *name*. This convenience function can be + used from the module's initialization function. The string *value* must be + null-terminated. Return ``-1`` on error, ``0`` on success. + + .. versionadded:: 2.0 + + +.. _iterator-objects: + +Iterator Objects +---------------- + +Python provides two general-purpose iterator objects. The first, a sequence +iterator, works with an arbitrary sequence supporting the :meth:`__getitem__` +method. The second works with a callable object and a sentinel value, calling +the callable for each item in the sequence, and ending the iteration when the +sentinel value is returned. + + +.. cvar:: PyTypeObject PySeqIter_Type + + Type object for iterator objects returned by :cfunc:`PySeqIter_New` and the + one-argument form of the :func:`iter` built-in function for built-in sequence + types. + + .. versionadded:: 2.2 + + +.. cfunction:: int PySeqIter_Check(op) + + Return true if the type of *op* is :cdata:`PySeqIter_Type`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PySeqIter_New(PyObject *seq) + + Return an iterator that works with a general sequence object, *seq*. The + iteration ends when the sequence raises :exc:`IndexError` for the subscripting + operation. + + .. versionadded:: 2.2 + + +.. cvar:: PyTypeObject PyCallIter_Type + + Type object for iterator objects returned by :cfunc:`PyCallIter_New` and the + two-argument form of the :func:`iter` built-in function. + + .. versionadded:: 2.2 + + +.. cfunction:: int PyCallIter_Check(op) + + Return true if the type of *op* is :cdata:`PyCallIter_Type`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyCallIter_New(PyObject *callable, PyObject *sentinel) + + Return a new iterator. The first parameter, *callable*, can be any Python + callable object that can be called with no parameters; each call to it should + return the next item in the iteration. When *callable* returns a value equal to + *sentinel*, the iteration will be terminated. + + .. versionadded:: 2.2 + + +.. _descriptor-objects: + +Descriptor Objects +------------------ + +"Descriptors" are objects that describe some attribute of an object. They are +found in the dictionary of type objects. + + +.. cvar:: PyTypeObject PyProperty_Type + + The type object for the built-in descriptor types. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyDescr_NewGetSet(PyTypeObject *type, struct PyGetSetDef *getset) + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyDescr_NewMember(PyTypeObject *type, struct PyMemberDef *meth) + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyDescr_NewMethod(PyTypeObject *type, struct PyMethodDef *meth) + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyDescr_NewWrapper(PyTypeObject *type, struct wrapperbase *wrapper, void *wrapped) + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyDescr_NewClassMethod(PyTypeObject *type, PyMethodDef *method) + + .. versionadded:: 2.3 + + +.. cfunction:: int PyDescr_IsData(PyObject *descr) + + Return true if the descriptor objects *descr* describes a data attribute, or + false if it describes a method. *descr* must be a descriptor object; there is + no error checking. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyWrapper_New(PyObject *, PyObject *) + + .. versionadded:: 2.2 + + +.. _slice-objects: + +Slice Objects +------------- + + +.. cvar:: PyTypeObject PySlice_Type + + .. index:: single: SliceType (in module types) + + The type object for slice objects. This is the same as ``slice`` and + ``types.SliceType``. + + +.. cfunction:: int PySlice_Check(PyObject *ob) + + Return true if *ob* is a slice object; *ob* must not be *NULL*. + + +.. cfunction:: PyObject* PySlice_New(PyObject *start, PyObject *stop, PyObject *step) + + Return a new slice object with the given values. The *start*, *stop*, and + *step* parameters are used as the values of the slice object attributes of the + same names. Any of the values may be *NULL*, in which case the ``None`` will be + used for the corresponding attribute. Return *NULL* if the new object could not + be allocated. + + +.. cfunction:: int PySlice_GetIndices(PySliceObject *slice, Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step) + + Retrieve the start, stop and step indices from the slice object *slice*, + assuming a sequence of length *length*. Treats indices greater than *length* as + errors. + + Returns 0 on success and -1 on error with no exception set (unless one of the + indices was not :const:`None` and failed to be converted to an integer, in which + case -1 is returned with an exception set). + + You probably do not want to use this function. If you want to use slice objects + in versions of Python prior to 2.3, you would probably do well to incorporate + the source of :cfunc:`PySlice_GetIndicesEx`, suitably renamed, in the source of + your extension. + + +.. cfunction:: int PySlice_GetIndicesEx(PySliceObject *slice, Py_ssize_t length, Py_ssize_t *start, Py_ssize_t *stop, Py_ssize_t *step, Py_ssize_t *slicelength) + + Usable replacement for :cfunc:`PySlice_GetIndices`. Retrieve the start, stop, + and step indices from the slice object *slice* assuming a sequence of length + *length*, and store the length of the slice in *slicelength*. Out of bounds + indices are clipped in a manner consistent with the handling of normal slices. + + Returns 0 on success and -1 on error with exception set. + + .. versionadded:: 2.3 + + +.. _weakrefobjects: + +Weak Reference Objects +---------------------- + +Python supports *weak references* as first-class objects. There are two +specific object types which directly implement weak references. The first is a +simple reference object, and the second acts as a proxy for the original object +as much as it can. + + +.. cfunction:: int PyWeakref_Check(ob) + + Return true if *ob* is either a reference or proxy object. + + .. versionadded:: 2.2 + + +.. cfunction:: int PyWeakref_CheckRef(ob) + + Return true if *ob* is a reference object. + + .. versionadded:: 2.2 + + +.. cfunction:: int PyWeakref_CheckProxy(ob) + + Return true if *ob* is a proxy object. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyWeakref_NewRef(PyObject *ob, PyObject *callback) + + Return a weak reference object for the object *ob*. This will always return + a new reference, but is not guaranteed to create a new object; an existing + reference object may be returned. The second parameter, *callback*, can be a + callable object that receives notification when *ob* is garbage collected; it + should accept a single parameter, which will be the weak reference object + itself. *callback* may also be ``None`` or *NULL*. If *ob* is not a + weakly-referencable object, or if *callback* is not callable, ``None``, or + *NULL*, this will return *NULL* and raise :exc:`TypeError`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyWeakref_NewProxy(PyObject *ob, PyObject *callback) + + Return a weak reference proxy object for the object *ob*. This will always + return a new reference, but is not guaranteed to create a new object; an + existing proxy object may be returned. The second parameter, *callback*, can + be a callable object that receives notification when *ob* is garbage + collected; it should accept a single parameter, which will be the weak + reference object itself. *callback* may also be ``None`` or *NULL*. If *ob* + is not a weakly-referencable object, or if *callback* is not callable, + ``None``, or *NULL*, this will return *NULL* and raise :exc:`TypeError`. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyWeakref_GetObject(PyObject *ref) + + Return the referenced object from a weak reference, *ref*. If the referent is + no longer live, returns ``None``. + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* PyWeakref_GET_OBJECT(PyObject *ref) + + Similar to :cfunc:`PyWeakref_GetObject`, but implemented as a macro that does no + error checking. + + .. versionadded:: 2.2 + + +.. _cobjects: + +CObjects +-------- + +.. index:: object: CObject + +Refer to *Extending and Embedding the Python Interpreter*, section 1.12, +"Providing a C API for an Extension Module," for more information on using these +objects. + + +.. ctype:: PyCObject + + This subtype of :ctype:`PyObject` represents an opaque value, useful for C + extension modules who need to pass an opaque value (as a :ctype:`void\*` + pointer) through Python code to other C code. It is often used to make a C + function pointer defined in one module available to other modules, so the + regular import mechanism can be used to access C APIs defined in dynamically + loaded modules. + + +.. cfunction:: int PyCObject_Check(PyObject *p) + + Return true if its argument is a :ctype:`PyCObject`. + + +.. cfunction:: PyObject* PyCObject_FromVoidPtr(void* cobj, void (*destr)(void *)) + + Create a :ctype:`PyCObject` from the ``void *`` *cobj*. The *destr* function + will be called when the object is reclaimed, unless it is *NULL*. + + +.. cfunction:: PyObject* PyCObject_FromVoidPtrAndDesc(void* cobj, void* desc, void (*destr)(void *, void *)) + + Create a :ctype:`PyCObject` from the :ctype:`void \*` *cobj*. The *destr* + function will be called when the object is reclaimed. The *desc* argument can + be used to pass extra callback data for the destructor function. + + +.. cfunction:: void* PyCObject_AsVoidPtr(PyObject* self) + + Return the object :ctype:`void \*` that the :ctype:`PyCObject` *self* was + created with. + + +.. cfunction:: void* PyCObject_GetDesc(PyObject* self) + + Return the description :ctype:`void \*` that the :ctype:`PyCObject` *self* was + created with. + + +.. cfunction:: int PyCObject_SetVoidPtr(PyObject* self, void* cobj) + + Set the void pointer inside *self* to *cobj*. The :ctype:`PyCObject` must not + have an associated destructor. Return true on success, false on failure. + + +.. _cell-objects: + +Cell Objects +------------ + +"Cell" objects are used to implement variables referenced by multiple scopes. +For each such variable, a cell object is created to store the value; the local +variables of each stack frame that references the value contains a reference to +the cells from outer scopes which also use that variable. When the value is +accessed, the value contained in the cell is used instead of the cell object +itself. This de-referencing of the cell object requires support from the +generated byte-code; these are not automatically de-referenced when accessed. +Cell objects are not likely to be useful elsewhere. + + +.. ctype:: PyCellObject + + The C structure used for cell objects. + + +.. cvar:: PyTypeObject PyCell_Type + + The type object corresponding to cell objects. + + +.. cfunction:: int PyCell_Check(ob) + + Return true if *ob* is a cell object; *ob* must not be *NULL*. + + +.. cfunction:: PyObject* PyCell_New(PyObject *ob) + + Create and return a new cell object containing the value *ob*. The parameter may + be *NULL*. + + +.. cfunction:: PyObject* PyCell_Get(PyObject *cell) + + Return the contents of the cell *cell*. + + +.. cfunction:: PyObject* PyCell_GET(PyObject *cell) + + Return the contents of the cell *cell*, but without checking that *cell* is + non-*NULL* and a cell object. + + +.. cfunction:: int PyCell_Set(PyObject *cell, PyObject *value) + + Set the contents of the cell object *cell* to *value*. This releases the + reference to any current content of the cell. *value* may be *NULL*. *cell* + must be non-*NULL*; if it is not a cell object, ``-1`` will be returned. On + success, ``0`` will be returned. + + +.. cfunction:: void PyCell_SET(PyObject *cell, PyObject *value) + + Sets the value of the cell object *cell* to *value*. No reference counts are + adjusted, and no checks are made for safety; *cell* must be non-*NULL* and must + be a cell object. + + +.. _gen-objects: + +Generator Objects +----------------- + +Generator objects are what Python uses to implement generator iterators. They +are normally created by iterating over a function that yields values, rather +than explicitly calling :cfunc:`PyGen_New`. + + +.. ctype:: PyGenObject + + The C structure used for generator objects. + + +.. cvar:: PyTypeObject PyGen_Type + + The type object corresponding to generator objects + + +.. cfunction:: int PyGen_Check(ob) + + Return true if *ob* is a generator object; *ob* must not be *NULL*. + + +.. cfunction:: int PyGen_CheckExact(ob) + + Return true if *ob*'s type is *PyGen_Type* is a generator object; *ob* must not + be *NULL*. + + +.. cfunction:: PyObject* PyGen_New(PyFrameObject *frame) + + Create and return a new generator object based on the *frame* object. A + reference to *frame* is stolen by this function. The parameter must not be + *NULL*. + + +.. _datetimeobjects: + +DateTime Objects +---------------- + +Various date and time objects are supplied by the :mod:`datetime` module. +Before using any of these functions, the header file :file:`datetime.h` must be +included in your source (note that this is not included by :file:`Python.h`), +and the macro :cfunc:`PyDateTime_IMPORT` must be invoked. The macro puts a +pointer to a C structure into a static variable, ``PyDateTimeAPI``, that is +used by the following macros. + +Type-check macros: + + +.. cfunction:: int PyDate_Check(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_DateType` or a subtype of + :cdata:`PyDateTime_DateType`. *ob* must not be *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDate_CheckExact(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_DateType`. *ob* must not be + *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_Check(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_DateTimeType` or a subtype of + :cdata:`PyDateTime_DateTimeType`. *ob* must not be *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_CheckExact(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_DateTimeType`. *ob* must not + be *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyTime_Check(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_TimeType` or a subtype of + :cdata:`PyDateTime_TimeType`. *ob* must not be *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyTime_CheckExact(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_TimeType`. *ob* must not be + *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDelta_Check(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_DeltaType` or a subtype of + :cdata:`PyDateTime_DeltaType`. *ob* must not be *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDelta_CheckExact(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_DeltaType`. *ob* must not be + *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyTZInfo_Check(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_TZInfoType` or a subtype of + :cdata:`PyDateTime_TZInfoType`. *ob* must not be *NULL*. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyTZInfo_CheckExact(PyObject *ob) + + Return true if *ob* is of type :cdata:`PyDateTime_TZInfoType`. *ob* must not be + *NULL*. + + .. versionadded:: 2.4 + +Macros to create objects: + + +.. cfunction:: PyObject* PyDate_FromDate(int year, int month, int day) + + Return a ``datetime.date`` object with the specified year, month and day. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PyDateTime_FromDateAndTime(int year, int month, int day, int hour, int minute, int second, int usecond) + + Return a ``datetime.datetime`` object with the specified year, month, day, hour, + minute, second and microsecond. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PyTime_FromTime(int hour, int minute, int second, int usecond) + + Return a ``datetime.time`` object with the specified hour, minute, second and + microsecond. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PyDelta_FromDSU(int days, int seconds, int useconds) + + Return a ``datetime.timedelta`` object representing the given number of days, + seconds and microseconds. Normalization is performed so that the resulting + number of microseconds and seconds lie in the ranges documented for + ``datetime.timedelta`` objects. + + .. versionadded:: 2.4 + +Macros to extract fields from date objects. The argument must be an instance of +:cdata:`PyDateTime_Date`, including subclasses (such as +:cdata:`PyDateTime_DateTime`). The argument must not be *NULL*, and the type is +not checked: + + +.. cfunction:: int PyDateTime_GET_YEAR(PyDateTime_Date *o) + + Return the year, as a positive int. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_GET_MONTH(PyDateTime_Date *o) + + Return the month, as an int from 1 through 12. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_GET_DAY(PyDateTime_Date *o) + + Return the day, as an int from 1 through 31. + + .. versionadded:: 2.4 + +Macros to extract fields from datetime objects. The argument must be an +instance of :cdata:`PyDateTime_DateTime`, including subclasses. The argument +must not be *NULL*, and the type is not checked: + + +.. cfunction:: int PyDateTime_DATE_GET_HOUR(PyDateTime_DateTime *o) + + Return the hour, as an int from 0 through 23. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_DATE_GET_MINUTE(PyDateTime_DateTime *o) + + Return the minute, as an int from 0 through 59. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_DATE_GET_SECOND(PyDateTime_DateTime *o) + + Return the second, as an int from 0 through 59. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_DATE_GET_MICROSECOND(PyDateTime_DateTime *o) + + Return the microsecond, as an int from 0 through 999999. + + .. versionadded:: 2.4 + +Macros to extract fields from time objects. The argument must be an instance of +:cdata:`PyDateTime_Time`, including subclasses. The argument must not be *NULL*, +and the type is not checked: + + +.. cfunction:: int PyDateTime_TIME_GET_HOUR(PyDateTime_Time *o) + + Return the hour, as an int from 0 through 23. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_TIME_GET_MINUTE(PyDateTime_Time *o) + + Return the minute, as an int from 0 through 59. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_TIME_GET_SECOND(PyDateTime_Time *o) + + Return the second, as an int from 0 through 59. + + .. versionadded:: 2.4 + + +.. cfunction:: int PyDateTime_TIME_GET_MICROSECOND(PyDateTime_Time *o) + + Return the microsecond, as an int from 0 through 999999. + + .. versionadded:: 2.4 + +Macros for the convenience of modules implementing the DB API: + + +.. cfunction:: PyObject* PyDateTime_FromTimestamp(PyObject *args) + + Create and return a new ``datetime.datetime`` object given an argument tuple + suitable for passing to ``datetime.datetime.fromtimestamp()``. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* PyDate_FromTimestamp(PyObject *args) + + Create and return a new ``datetime.date`` object given an argument tuple + suitable for passing to ``datetime.date.fromtimestamp()``. + + .. versionadded:: 2.4 + + +.. _setobjects: + +Set Objects +----------- + +.. sectionauthor:: Raymond D. Hettinger + + +.. index:: + object: set + object: frozenset + +.. versionadded:: 2.5 + +This section details the public API for :class:`set` and :class:`frozenset` +objects. Any functionality not listed below is best accessed using the either +the abstract object protocol (including :cfunc:`PyObject_CallMethod`, +:cfunc:`PyObject_RichCompareBool`, :cfunc:`PyObject_Hash`, +:cfunc:`PyObject_Repr`, :cfunc:`PyObject_IsTrue`, :cfunc:`PyObject_Print`, and +:cfunc:`PyObject_GetIter`) or the abstract number protocol (including +:cfunc:`PyNumber_And`, :cfunc:`PyNumber_Subtract`, :cfunc:`PyNumber_Or`, +:cfunc:`PyNumber_Xor`, :cfunc:`PyNumber_InPlaceAnd`, +:cfunc:`PyNumber_InPlaceSubtract`, :cfunc:`PyNumber_InPlaceOr`, and +:cfunc:`PyNumber_InPlaceXor`). + + +.. ctype:: PySetObject + + This subtype of :ctype:`PyObject` is used to hold the internal data for both + :class:`set` and :class:`frozenset` objects. It is like a :ctype:`PyDictObject` + in that it is a fixed size for small sets (much like tuple storage) and will + point to a separate, variable sized block of memory for medium and large sized + sets (much like list storage). None of the fields of this structure should be + considered public and are subject to change. All access should be done through + the documented API rather than by manipulating the values in the structure. + + +.. cvar:: PyTypeObject PySet_Type + + This is an instance of :ctype:`PyTypeObject` representing the Python + :class:`set` type. + + +.. cvar:: PyTypeObject PyFrozenSet_Type + + This is an instance of :ctype:`PyTypeObject` representing the Python + :class:`frozenset` type. + +The following type check macros work on pointers to any Python object. Likewise, +the constructor functions work with any iterable Python object. + + +.. cfunction:: int PyAnySet_Check(PyObject *p) + + Return true if *p* is a :class:`set` object, a :class:`frozenset` object, or an + instance of a subtype. + + +.. cfunction:: int PyAnySet_CheckExact(PyObject *p) + + Return true if *p* is a :class:`set` object or a :class:`frozenset` object but + not an instance of a subtype. + + +.. cfunction:: int PyFrozenSet_CheckExact(PyObject *p) + + Return true if *p* is a :class:`frozenset` object but not an instance of a + subtype. + + +.. cfunction:: PyObject* PySet_New(PyObject *iterable) + + Return a new :class:`set` containing objects returned by the *iterable*. The + *iterable* may be *NULL* to create a new empty set. Return the new set on + success or *NULL* on failure. Raise :exc:`TypeError` if *iterable* is not + actually iterable. The constructor is also useful for copying a set + (``c=set(s)``). + + +.. cfunction:: PyObject* PyFrozenSet_New(PyObject *iterable) + + Return a new :class:`frozenset` containing objects returned by the *iterable*. + The *iterable* may be *NULL* to create a new empty frozenset. Return the new + set on success or *NULL* on failure. Raise :exc:`TypeError` if *iterable* is + not actually iterable. + +The following functions and macros are available for instances of :class:`set` +or :class:`frozenset` or instances of their subtypes. + + +.. cfunction:: int PySet_Size(PyObject *anyset) + + .. index:: builtin: len + + Return the length of a :class:`set` or :class:`frozenset` object. Equivalent to + ``len(anyset)``. Raises a :exc:`PyExc_SystemError` if *anyset* is not a + :class:`set`, :class:`frozenset`, or an instance of a subtype. + + +.. cfunction:: int PySet_GET_SIZE(PyObject *anyset) + + Macro form of :cfunc:`PySet_Size` without error checking. + + +.. cfunction:: int PySet_Contains(PyObject *anyset, PyObject *key) + + Return 1 if found, 0 if not found, and -1 if an error is encountered. Unlike + the Python :meth:`__contains__` method, this function does not automatically + convert unhashable sets into temporary frozensets. Raise a :exc:`TypeError` if + the *key* is unhashable. Raise :exc:`PyExc_SystemError` if *anyset* is not a + :class:`set`, :class:`frozenset`, or an instance of a subtype. + +The following functions are available for instances of :class:`set` or its +subtypes but not for instances of :class:`frozenset` or its subtypes. + + +.. cfunction:: int PySet_Add(PyObject *set, PyObject *key) + + Add *key* to a :class:`set` instance. Does not apply to :class:`frozenset` + instances. Return 0 on success or -1 on failure. Raise a :exc:`TypeError` if + the *key* is unhashable. Raise a :exc:`MemoryError` if there is no room to grow. + Raise a :exc:`SystemError` if *set* is an not an instance of :class:`set` or its + subtype. + + +.. cfunction:: int PySet_Discard(PyObject *set, PyObject *key) + + Return 1 if found and removed, 0 if not found (no action taken), and -1 if an + error is encountered. Does not raise :exc:`KeyError` for missing keys. Raise a + :exc:`TypeError` if the *key* is unhashable. Unlike the Python :meth:`discard` + method, this function does not automatically convert unhashable sets into + temporary frozensets. Raise :exc:`PyExc_SystemError` if *set* is an not an + instance of :class:`set` or its subtype. + + +.. cfunction:: PyObject* PySet_Pop(PyObject *set) + + Return a new reference to an arbitrary object in the *set*, and removes the + object from the *set*. Return *NULL* on failure. Raise :exc:`KeyError` if the + set is empty. Raise a :exc:`SystemError` if *set* is an not an instance of + :class:`set` or its subtype. + + +.. cfunction:: int PySet_Clear(PyObject *set) + + Empty an existing set of all elements. + diff --git a/Doc/c-api/exceptions.rst b/Doc/c-api/exceptions.rst new file mode 100644 index 0000000..68ac090 --- /dev/null +++ b/Doc/c-api/exceptions.rst @@ -0,0 +1,515 @@ +.. highlightlang:: c + + +.. _exceptionhandling: + +****************** +Exception Handling +****************** + +The functions described in this chapter will let you handle and raise Python +exceptions. It is important to understand some of the basics of Python +exception handling. It works somewhat like the Unix :cdata:`errno` variable: +there is a global indicator (per thread) of the last error that occurred. Most +functions don't clear this on success, but will set it to indicate the cause of +the error on failure. Most functions also return an error indicator, usually +*NULL* if they are supposed to return a pointer, or ``-1`` if they return an +integer (exception: the :cfunc:`PyArg_\*` functions return ``1`` for success and +``0`` for failure). + +When a function must fail because some function it called failed, it generally +doesn't set the error indicator; the function it called already set it. It is +responsible for either handling the error and clearing the exception or +returning after cleaning up any resources it holds (such as object references or +memory allocations); it should *not* continue normally if it is not prepared to +handle the error. If returning due to an error, it is important to indicate to +the caller that an error has been set. If the error is not handled or carefully +propagated, additional calls into the Python/C API may not behave as intended +and may fail in mysterious ways. + +The error indicator consists of three Python objects corresponding to the result +of ``sys.exc_info()``. API functions exist to interact with the error indicator +in various ways. There is a separate error indicator for each thread. + +.. % XXX Order of these should be more thoughtful. +.. % Either alphabetical or some kind of structure. + + +.. cfunction:: void PyErr_Print() + + Print a standard traceback to ``sys.stderr`` and clear the error indicator. + Call this function only when the error indicator is set. (Otherwise it will + cause a fatal error!) + + +.. cfunction:: PyObject* PyErr_Occurred() + + Test whether the error indicator is set. If set, return the exception *type* + (the first argument to the last call to one of the :cfunc:`PyErr_Set\*` + functions or to :cfunc:`PyErr_Restore`). If not set, return *NULL*. You do not + own a reference to the return value, so you do not need to :cfunc:`Py_DECREF` + it. + + .. note:: + + Do not compare the return value to a specific exception; use + :cfunc:`PyErr_ExceptionMatches` instead, shown below. (The comparison could + easily fail since the exception may be an instance instead of a class, in the + case of a class exception, or it may the a subclass of the expected exception.) + + +.. cfunction:: int PyErr_ExceptionMatches(PyObject *exc) + + Equivalent to ``PyErr_GivenExceptionMatches(PyErr_Occurred(), exc)``. This + should only be called when an exception is actually set; a memory access + violation will occur if no exception has been raised. + + +.. cfunction:: int PyErr_GivenExceptionMatches(PyObject *given, PyObject *exc) + + Return true if the *given* exception matches the exception in *exc*. If *exc* + is a class object, this also returns true when *given* is an instance of a + subclass. If *exc* is a tuple, all exceptions in the tuple (and recursively in + subtuples) are searched for a match. If *given* is *NULL*, a memory access + violation will occur. + + +.. cfunction:: void PyErr_NormalizeException(PyObject**exc, PyObject**val, PyObject**tb) + + Under certain circumstances, the values returned by :cfunc:`PyErr_Fetch` below + can be "unnormalized", meaning that ``*exc`` is a class object but ``*val`` is + not an instance of the same class. This function can be used to instantiate + the class in that case. If the values are already normalized, nothing happens. + The delayed normalization is implemented to improve performance. + + +.. cfunction:: void PyErr_Clear() + + Clear the error indicator. If the error indicator is not set, there is no + effect. + + +.. cfunction:: void PyErr_Fetch(PyObject **ptype, PyObject **pvalue, PyObject **ptraceback) + + Retrieve the error indicator into three variables whose addresses are passed. + If the error indicator is not set, set all three variables to *NULL*. If it is + set, it will be cleared and you own a reference to each object retrieved. The + value and traceback object may be *NULL* even when the type object is not. + + .. note:: + + This function is normally only used by code that needs to handle exceptions or + by code that needs to save and restore the error indicator temporarily. + + +.. cfunction:: void PyErr_Restore(PyObject *type, PyObject *value, PyObject *traceback) + + Set the error indicator from the three objects. If the error indicator is + already set, it is cleared first. If the objects are *NULL*, the error + indicator is cleared. Do not pass a *NULL* type and non-*NULL* value or + traceback. The exception type should be a class. Do not pass an invalid + exception type or value. (Violating these rules will cause subtle problems + later.) This call takes away a reference to each object: you must own a + reference to each object before the call and after the call you no longer own + these references. (If you don't understand this, don't use this function. I + warned you.) + + .. note:: + + This function is normally only used by code that needs to save and restore the + error indicator temporarily; use :cfunc:`PyErr_Fetch` to save the current + exception state. + + +.. cfunction:: void PyErr_SetString(PyObject *type, const char *message) + + This is the most common way to set the error indicator. The first argument + specifies the exception type; it is normally one of the standard exceptions, + e.g. :cdata:`PyExc_RuntimeError`. You need not increment its reference count. + The second argument is an error message; it is converted to a string object. + + +.. cfunction:: void PyErr_SetObject(PyObject *type, PyObject *value) + + This function is similar to :cfunc:`PyErr_SetString` but lets you specify an + arbitrary Python object for the "value" of the exception. + + +.. cfunction:: PyObject* PyErr_Format(PyObject *exception, const char *format, ...) + + This function sets the error indicator and returns *NULL*. *exception* should be + a Python exception (class, not an instance). *format* should be a string, + containing format codes, similar to :cfunc:`printf`. The ``width.precision`` + before a format code is parsed, but the width part is ignored. + + .. % This should be exactly the same as the table in PyString_FromFormat. + .. % One should just refer to the other. + .. % The descriptions for %zd and %zu are wrong, but the truth is complicated + .. % because not all compilers support the %z width modifier -- we fake it + .. % when necessary via interpolating PY_FORMAT_SIZE_T. + .. % %u, %lu, %zu should have "new in Python 2.5" blurbs. + + +-------------------+---------------+--------------------------------+ + | Format Characters | Type | Comment | + +===================+===============+================================+ + | :attr:`%%` | *n/a* | The literal % character. | + +-------------------+---------------+--------------------------------+ + | :attr:`%c` | int | A single character, | + | | | represented as an C int. | + +-------------------+---------------+--------------------------------+ + | :attr:`%d` | int | Exactly equivalent to | + | | | ``printf("%d")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%u` | unsigned int | Exactly equivalent to | + | | | ``printf("%u")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%ld` | long | Exactly equivalent to | + | | | ``printf("%ld")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%lu` | unsigned long | Exactly equivalent to | + | | | ``printf("%lu")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%zd` | Py_ssize_t | Exactly equivalent to | + | | | ``printf("%zd")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%zu` | size_t | Exactly equivalent to | + | | | ``printf("%zu")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%i` | int | Exactly equivalent to | + | | | ``printf("%i")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%x` | int | Exactly equivalent to | + | | | ``printf("%x")``. | + +-------------------+---------------+--------------------------------+ + | :attr:`%s` | char\* | A null-terminated C character | + | | | array. | + +-------------------+---------------+--------------------------------+ + | :attr:`%p` | void\* | The hex representation of a C | + | | | pointer. Mostly equivalent to | + | | | ``printf("%p")`` except that | + | | | it is guaranteed to start with | + | | | the literal ``0x`` regardless | + | | | of what the platform's | + | | | ``printf`` yields. | + +-------------------+---------------+--------------------------------+ + + An unrecognized format character causes all the rest of the format string to be + copied as-is to the result string, and any extra arguments discarded. + + +.. cfunction:: void PyErr_SetNone(PyObject *type) + + This is a shorthand for ``PyErr_SetObject(type, Py_None)``. + + +.. cfunction:: int PyErr_BadArgument() + + This is a shorthand for ``PyErr_SetString(PyExc_TypeError, message)``, where + *message* indicates that a built-in operation was invoked with an illegal + argument. It is mostly for internal use. + + +.. cfunction:: PyObject* PyErr_NoMemory() + + This is a shorthand for ``PyErr_SetNone(PyExc_MemoryError)``; it returns *NULL* + so an object allocation function can write ``return PyErr_NoMemory();`` when it + runs out of memory. + + +.. cfunction:: PyObject* PyErr_SetFromErrno(PyObject *type) + + .. index:: single: strerror() + + This is a convenience function to raise an exception when a C library function + has returned an error and set the C variable :cdata:`errno`. It constructs a + tuple object whose first item is the integer :cdata:`errno` value and whose + second item is the corresponding error message (gotten from :cfunc:`strerror`), + and then calls ``PyErr_SetObject(type, object)``. On Unix, when the + :cdata:`errno` value is :const:`EINTR`, indicating an interrupted system call, + this calls :cfunc:`PyErr_CheckSignals`, and if that set the error indicator, + leaves it set to that. The function always returns *NULL*, so a wrapper + function around a system call can write ``return PyErr_SetFromErrno(type);`` + when the system call returns an error. + + +.. cfunction:: PyObject* PyErr_SetFromErrnoWithFilename(PyObject *type, const char *filename) + + Similar to :cfunc:`PyErr_SetFromErrno`, with the additional behavior that if + *filename* is not *NULL*, it is passed to the constructor of *type* as a third + parameter. In the case of exceptions such as :exc:`IOError` and :exc:`OSError`, + this is used to define the :attr:`filename` attribute of the exception instance. + + +.. cfunction:: PyObject* PyErr_SetFromWindowsErr(int ierr) + + This is a convenience function to raise :exc:`WindowsError`. If called with + *ierr* of :cdata:`0`, the error code returned by a call to :cfunc:`GetLastError` + is used instead. It calls the Win32 function :cfunc:`FormatMessage` to retrieve + the Windows description of error code given by *ierr* or :cfunc:`GetLastError`, + then it constructs a tuple object whose first item is the *ierr* value and whose + second item is the corresponding error message (gotten from + :cfunc:`FormatMessage`), and then calls ``PyErr_SetObject(PyExc_WindowsError, + object)``. This function always returns *NULL*. Availability: Windows. + + +.. cfunction:: PyObject* PyErr_SetExcFromWindowsErr(PyObject *type, int ierr) + + Similar to :cfunc:`PyErr_SetFromWindowsErr`, with an additional parameter + specifying the exception type to be raised. Availability: Windows. + + .. versionadded:: 2.3 + + +.. cfunction:: PyObject* PyErr_SetFromWindowsErrWithFilename(int ierr, const char *filename) + + Similar to :cfunc:`PyErr_SetFromWindowsErr`, with the additional behavior that + if *filename* is not *NULL*, it is passed to the constructor of + :exc:`WindowsError` as a third parameter. Availability: Windows. + + +.. cfunction:: PyObject* PyErr_SetExcFromWindowsErrWithFilename(PyObject *type, int ierr, char *filename) + + Similar to :cfunc:`PyErr_SetFromWindowsErrWithFilename`, with an additional + parameter specifying the exception type to be raised. Availability: Windows. + + .. versionadded:: 2.3 + + +.. cfunction:: void PyErr_BadInternalCall() + + This is a shorthand for ``PyErr_SetString(PyExc_TypeError, message)``, where + *message* indicates that an internal operation (e.g. a Python/C API function) + was invoked with an illegal argument. It is mostly for internal use. + + +.. cfunction:: int PyErr_WarnEx(PyObject *category, char *message, int stacklevel) + + Issue a warning message. The *category* argument is a warning category (see + below) or *NULL*; the *message* argument is a message string. *stacklevel* is a + positive number giving a number of stack frames; the warning will be issued from + the currently executing line of code in that stack frame. A *stacklevel* of 1 + is the function calling :cfunc:`PyErr_WarnEx`, 2 is the function above that, + and so forth. + + This function normally prints a warning message to *sys.stderr*; however, it is + also possible that the user has specified that warnings are to be turned into + errors, and in that case this will raise an exception. It is also possible that + the function raises an exception because of a problem with the warning machinery + (the implementation imports the :mod:`warnings` module to do the heavy lifting). + The return value is ``0`` if no exception is raised, or ``-1`` if an exception + is raised. (It is not possible to determine whether a warning message is + actually printed, nor what the reason is for the exception; this is + intentional.) If an exception is raised, the caller should do its normal + exception handling (for example, :cfunc:`Py_DECREF` owned references and return + an error value). + + Warning categories must be subclasses of :cdata:`Warning`; the default warning + category is :cdata:`RuntimeWarning`. The standard Python warning categories are + available as global variables whose names are ``PyExc_`` followed by the Python + exception name. These have the type :ctype:`PyObject\*`; they are all class + objects. Their names are :cdata:`PyExc_Warning`, :cdata:`PyExc_UserWarning`, + :cdata:`PyExc_UnicodeWarning`, :cdata:`PyExc_DeprecationWarning`, + :cdata:`PyExc_SyntaxWarning`, :cdata:`PyExc_RuntimeWarning`, and + :cdata:`PyExc_FutureWarning`. :cdata:`PyExc_Warning` is a subclass of + :cdata:`PyExc_Exception`; the other warning categories are subclasses of + :cdata:`PyExc_Warning`. + + For information about warning control, see the documentation for the + :mod:`warnings` module and the :option:`-W` option in the command line + documentation. There is no C API for warning control. + + +.. cfunction:: int PyErr_WarnExplicit(PyObject *category, const char *message, const char *filename, int lineno, const char *module, PyObject *registry) + + Issue a warning message with explicit control over all warning attributes. This + is a straightforward wrapper around the Python function + :func:`warnings.warn_explicit`, see there for more information. The *module* + and *registry* arguments may be set to *NULL* to get the default effect + described there. + + +.. cfunction:: int PyErr_CheckSignals() + + .. index:: + module: signal + single: SIGINT + single: KeyboardInterrupt (built-in exception) + + This function interacts with Python's signal handling. It checks whether a + signal has been sent to the processes and if so, invokes the corresponding + signal handler. If the :mod:`signal` module is supported, this can invoke a + signal handler written in Python. In all cases, the default effect for + :const:`SIGINT` is to raise the :exc:`KeyboardInterrupt` exception. If an + exception is raised the error indicator is set and the function returns ``-1``; + otherwise the function returns ``0``. The error indicator may or may not be + cleared if it was previously set. + + +.. cfunction:: void PyErr_SetInterrupt() + + .. index:: + single: SIGINT + single: KeyboardInterrupt (built-in exception) + + This function simulates the effect of a :const:`SIGINT` signal arriving --- the + next time :cfunc:`PyErr_CheckSignals` is called, :exc:`KeyboardInterrupt` will + be raised. It may be called without holding the interpreter lock. + + .. % XXX This was described as obsolete, but is used in + .. % thread.interrupt_main() (used from IDLE), so it's still needed. + + +.. cfunction:: PyObject* PyErr_NewException(char *name, PyObject *base, PyObject *dict) + + This utility function creates and returns a new exception object. The *name* + argument must be the name of the new exception, a C string of the form + ``module.class``. The *base* and *dict* arguments are normally *NULL*. This + creates a class object derived from :exc:`Exception` (accessible in C as + :cdata:`PyExc_Exception`). + + The :attr:`__module__` attribute of the new class is set to the first part (up + to the last dot) of the *name* argument, and the class name is set to the last + part (after the last dot). The *base* argument can be used to specify alternate + base classes; it can either be only one class or a tuple of classes. The *dict* + argument can be used to specify a dictionary of class variables and methods. + + +.. cfunction:: void PyErr_WriteUnraisable(PyObject *obj) + + This utility function prints a warning message to ``sys.stderr`` when an + exception has been set but it is impossible for the interpreter to actually + raise the exception. It is used, for example, when an exception occurs in an + :meth:`__del__` method. + + The function is called with a single argument *obj* that identifies the context + in which the unraisable exception occurred. The repr of *obj* will be printed in + the warning message. + + +.. _standardexceptions: + +Standard Exceptions +=================== + +All standard Python exceptions are available as global variables whose names are +``PyExc_`` followed by the Python exception name. These have the type +:ctype:`PyObject\*`; they are all class objects. For completeness, here are all +the variables: + ++------------------------------------+----------------------------+----------+ +| C Name | Python Name | Notes | ++====================================+============================+==========+ +| :cdata:`PyExc_BaseException` | :exc:`BaseException` | (1), (4) | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_Exception` | :exc:`Exception` | \(1) | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_ArithmeticError` | :exc:`ArithmeticError` | \(1) | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_LookupError` | :exc:`LookupError` | \(1) | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_AssertionError` | :exc:`AssertionError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_AttributeError` | :exc:`AttributeError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_EOFError` | :exc:`EOFError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_EnvironmentError` | :exc:`EnvironmentError` | \(1) | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_FloatingPointError` | :exc:`FloatingPointError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_IOError` | :exc:`IOError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_ImportError` | :exc:`ImportError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_IndexError` | :exc:`IndexError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_KeyError` | :exc:`KeyError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_KeyboardInterrupt` | :exc:`KeyboardInterrupt` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_MemoryError` | :exc:`MemoryError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_NameError` | :exc:`NameError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_NotImplementedError` | :exc:`NotImplementedError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_OSError` | :exc:`OSError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_OverflowError` | :exc:`OverflowError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_ReferenceError` | :exc:`ReferenceError` | \(2) | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_RuntimeError` | :exc:`RuntimeError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_SyntaxError` | :exc:`SyntaxError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_SystemError` | :exc:`SystemError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_SystemExit` | :exc:`SystemExit` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_TypeError` | :exc:`TypeError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_ValueError` | :exc:`ValueError` | | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_WindowsError` | :exc:`WindowsError` | \(3) | ++------------------------------------+----------------------------+----------+ +| :cdata:`PyExc_ZeroDivisionError` | :exc:`ZeroDivisionError` | | ++------------------------------------+----------------------------+----------+ + +.. index:: + single: PyExc_BaseException + single: PyExc_Exception + single: PyExc_ArithmeticError + single: PyExc_LookupError + single: PyExc_AssertionError + single: PyExc_AttributeError + single: PyExc_EOFError + single: PyExc_EnvironmentError + single: PyExc_FloatingPointError + single: PyExc_IOError + single: PyExc_ImportError + single: PyExc_IndexError + single: PyExc_KeyError + single: PyExc_KeyboardInterrupt + single: PyExc_MemoryError + single: PyExc_NameError + single: PyExc_NotImplementedError + single: PyExc_OSError + single: PyExc_OverflowError + single: PyExc_ReferenceError + single: PyExc_RuntimeError + single: PyExc_SyntaxError + single: PyExc_SystemError + single: PyExc_SystemExit + single: PyExc_TypeError + single: PyExc_ValueError + single: PyExc_WindowsError + single: PyExc_ZeroDivisionError + +Notes: + +(1) + This is a base class for other standard exceptions. + +(2) + This is the same as :exc:`weakref.ReferenceError`. + +(3) + Only defined on Windows; protect code that uses this by testing that the + preprocessor macro ``MS_WINDOWS`` is defined. + +(4) + .. versionadded:: 2.5 + + +Deprecation of String Exceptions +================================ + +.. index:: single: BaseException (built-in exception) + +All exceptions built into Python or provided in the standard library are derived +from :exc:`BaseException`. + +String exceptions are still supported in the interpreter to allow existing code +to run unmodified, but this will also change in a future release. + diff --git a/Doc/c-api/index.rst b/Doc/c-api/index.rst new file mode 100644 index 0000000..c643312 --- /dev/null +++ b/Doc/c-api/index.rst @@ -0,0 +1,33 @@ +.. _c-api-index: + +################################## + Python/C API Reference Manual +################################## + +:Release: |version| +:Date: |today| + +This manual documents the API used by C and C++ programmers who want to write +extension modules or embed Python. It is a companion to :ref:`extending-index`, +which describes the general principles of extension writing but does not +document the API functions in detail. + +.. warning:: + + The current version of this document is somewhat incomplete. However, most of + the important functions, types and structures are described. + + +.. toctree:: + :maxdepth: 2 + + intro.rst + veryhigh.rst + refcounting.rst + exceptions.rst + utilities.rst + abstract.rst + concrete.rst + init.rst + memory.rst + newtypes.rst diff --git a/Doc/c-api/init.rst b/Doc/c-api/init.rst new file mode 100644 index 0000000..2509e0b --- /dev/null +++ b/Doc/c-api/init.rst @@ -0,0 +1,936 @@ +.. highlightlang:: c + + +.. _initialization: + +***************************************** +Initialization, Finalization, and Threads +***************************************** + + +.. cfunction:: void Py_Initialize() + + .. index:: + single: Py_SetProgramName() + single: PyEval_InitThreads() + single: PyEval_ReleaseLock() + single: PyEval_AcquireLock() + single: modules (in module sys) + single: path (in module sys) + module: __builtin__ + module: __main__ + module: sys + triple: module; search; path + single: PySys_SetArgv() + single: Py_Finalize() + + Initialize the Python interpreter. In an application embedding Python, this + should be called before using any other Python/C API functions; with the + exception of :cfunc:`Py_SetProgramName`, :cfunc:`PyEval_InitThreads`, + :cfunc:`PyEval_ReleaseLock`, and :cfunc:`PyEval_AcquireLock`. This initializes + the table of loaded modules (``sys.modules``), and creates the fundamental + modules :mod:`__builtin__`, :mod:`__main__` and :mod:`sys`. It also initializes + the module search path (``sys.path``). It does not set ``sys.argv``; use + :cfunc:`PySys_SetArgv` for that. This is a no-op when called for a second time + (without calling :cfunc:`Py_Finalize` first). There is no return value; it is a + fatal error if the initialization fails. + + +.. cfunction:: void Py_InitializeEx(int initsigs) + + This function works like :cfunc:`Py_Initialize` if *initsigs* is 1. If + *initsigs* is 0, it skips initialization registration of signal handlers, which + might be useful when Python is embedded. + + .. versionadded:: 2.4 + + +.. cfunction:: int Py_IsInitialized() + + Return true (nonzero) when the Python interpreter has been initialized, false + (zero) if not. After :cfunc:`Py_Finalize` is called, this returns false until + :cfunc:`Py_Initialize` is called again. + + +.. cfunction:: void Py_Finalize() + + Undo all initializations made by :cfunc:`Py_Initialize` and subsequent use of + Python/C API functions, and destroy all sub-interpreters (see + :cfunc:`Py_NewInterpreter` below) that were created and not yet destroyed since + the last call to :cfunc:`Py_Initialize`. Ideally, this frees all memory + allocated by the Python interpreter. This is a no-op when called for a second + time (without calling :cfunc:`Py_Initialize` again first). There is no return + value; errors during finalization are ignored. + + This function is provided for a number of reasons. An embedding application + might want to restart Python without having to restart the application itself. + An application that has loaded the Python interpreter from a dynamically + loadable library (or DLL) might want to free all memory allocated by Python + before unloading the DLL. During a hunt for memory leaks in an application a + developer might want to free all memory allocated by Python before exiting from + the application. + + **Bugs and caveats:** The destruction of modules and objects in modules is done + in random order; this may cause destructors (:meth:`__del__` methods) to fail + when they depend on other objects (even functions) or modules. Dynamically + loaded extension modules loaded by Python are not unloaded. Small amounts of + memory allocated by the Python interpreter may not be freed (if you find a leak, + please report it). Memory tied up in circular references between objects is not + freed. Some memory allocated by extension modules may not be freed. Some + extensions may not work properly if their initialization routine is called more + than once; this can happen if an application calls :cfunc:`Py_Initialize` and + :cfunc:`Py_Finalize` more than once. + + +.. cfunction:: PyThreadState* Py_NewInterpreter() + + .. index:: + module: __builtin__ + module: __main__ + module: sys + single: stdout (in module sys) + single: stderr (in module sys) + single: stdin (in module sys) + + Create a new sub-interpreter. This is an (almost) totally separate environment + for the execution of Python code. In particular, the new interpreter has + separate, independent versions of all imported modules, including the + fundamental modules :mod:`__builtin__`, :mod:`__main__` and :mod:`sys`. The + table of loaded modules (``sys.modules``) and the module search path + (``sys.path``) are also separate. The new environment has no ``sys.argv`` + variable. It has new standard I/O stream file objects ``sys.stdin``, + ``sys.stdout`` and ``sys.stderr`` (however these refer to the same underlying + :ctype:`FILE` structures in the C library). + + The return value points to the first thread state created in the new + sub-interpreter. This thread state is made in the current thread state. + Note that no actual thread is created; see the discussion of thread states + below. If creation of the new interpreter is unsuccessful, *NULL* is + returned; no exception is set since the exception state is stored in the + current thread state and there may not be a current thread state. (Like all + other Python/C API functions, the global interpreter lock must be held before + calling this function and is still held when it returns; however, unlike most + other Python/C API functions, there needn't be a current thread state on + entry.) + + .. index:: + single: Py_Finalize() + single: Py_Initialize() + + Extension modules are shared between (sub-)interpreters as follows: the first + time a particular extension is imported, it is initialized normally, and a + (shallow) copy of its module's dictionary is squirreled away. When the same + extension is imported by another (sub-)interpreter, a new module is initialized + and filled with the contents of this copy; the extension's ``init`` function is + not called. Note that this is different from what happens when an extension is + imported after the interpreter has been completely re-initialized by calling + :cfunc:`Py_Finalize` and :cfunc:`Py_Initialize`; in that case, the extension's + ``initmodule`` function *is* called again. + + .. index:: single: close() (in module os) + + **Bugs and caveats:** Because sub-interpreters (and the main interpreter) are + part of the same process, the insulation between them isn't perfect --- for + example, using low-level file operations like :func:`os.close` they can + (accidentally or maliciously) affect each other's open files. Because of the + way extensions are shared between (sub-)interpreters, some extensions may not + work properly; this is especially likely when the extension makes use of + (static) global variables, or when the extension manipulates its module's + dictionary after its initialization. It is possible to insert objects created + in one sub-interpreter into a namespace of another sub-interpreter; this should + be done with great care to avoid sharing user-defined functions, methods, + instances or classes between sub-interpreters, since import operations executed + by such objects may affect the wrong (sub-)interpreter's dictionary of loaded + modules. (XXX This is a hard-to-fix bug that will be addressed in a future + release.) + + Also note that the use of this functionality is incompatible with extension + modules such as PyObjC and ctypes that use the :cfunc:`PyGILState_\*` APIs (and + this is inherent in the way the :cfunc:`PyGILState_\*` functions work). Simple + things may work, but confusing behavior will always be near. + + +.. cfunction:: void Py_EndInterpreter(PyThreadState *tstate) + + .. index:: single: Py_Finalize() + + Destroy the (sub-)interpreter represented by the given thread state. The given + thread state must be the current thread state. See the discussion of thread + states below. When the call returns, the current thread state is *NULL*. All + thread states associated with this interpreter are destroyed. (The global + interpreter lock must be held before calling this function and is still held + when it returns.) :cfunc:`Py_Finalize` will destroy all sub-interpreters that + haven't been explicitly destroyed at that point. + + +.. cfunction:: void Py_SetProgramName(char *name) + + .. index:: + single: Py_Initialize() + single: main() + single: Py_GetPath() + + This function should be called before :cfunc:`Py_Initialize` is called for + the first time, if it is called at all. It tells the interpreter the value + of the ``argv[0]`` argument to the :cfunc:`main` function of the program. + This is used by :cfunc:`Py_GetPath` and some other functions below to find + the Python run-time libraries relative to the interpreter executable. The + default value is ``'python'``. The argument should point to a + zero-terminated character string in static storage whose contents will not + change for the duration of the program's execution. No code in the Python + interpreter will change the contents of this storage. + + +.. cfunction:: char* Py_GetProgramName() + + .. index:: single: Py_SetProgramName() + + Return the program name set with :cfunc:`Py_SetProgramName`, or the default. + The returned string points into static storage; the caller should not modify its + value. + + +.. cfunction:: char* Py_GetPrefix() + + Return the *prefix* for installed platform-independent files. This is derived + through a number of complicated rules from the program name set with + :cfunc:`Py_SetProgramName` and some environment variables; for example, if the + program name is ``'/usr/local/bin/python'``, the prefix is ``'/usr/local'``. The + returned string points into static storage; the caller should not modify its + value. This corresponds to the :makevar:`prefix` variable in the top-level + :file:`Makefile` and the :option:`--prefix` argument to the :program:`configure` + script at build time. The value is available to Python code as ``sys.prefix``. + It is only useful on Unix. See also the next function. + + +.. cfunction:: char* Py_GetExecPrefix() + + Return the *exec-prefix* for installed platform-*dependent* files. This is + derived through a number of complicated rules from the program name set with + :cfunc:`Py_SetProgramName` and some environment variables; for example, if the + program name is ``'/usr/local/bin/python'``, the exec-prefix is + ``'/usr/local'``. The returned string points into static storage; the caller + should not modify its value. This corresponds to the :makevar:`exec_prefix` + variable in the top-level :file:`Makefile` and the :option:`--exec-prefix` + argument to the :program:`configure` script at build time. The value is + available to Python code as ``sys.exec_prefix``. It is only useful on Unix. + + Background: The exec-prefix differs from the prefix when platform dependent + files (such as executables and shared libraries) are installed in a different + directory tree. In a typical installation, platform dependent files may be + installed in the :file:`/usr/local/plat` subtree while platform independent may + be installed in :file:`/usr/local`. + + Generally speaking, a platform is a combination of hardware and software + families, e.g. Sparc machines running the Solaris 2.x operating system are + considered the same platform, but Intel machines running Solaris 2.x are another + platform, and Intel machines running Linux are yet another platform. Different + major revisions of the same operating system generally also form different + platforms. Non-Unix operating systems are a different story; the installation + strategies on those systems are so different that the prefix and exec-prefix are + meaningless, and set to the empty string. Note that compiled Python bytecode + files are platform independent (but not independent from the Python version by + which they were compiled!). + + System administrators will know how to configure the :program:`mount` or + :program:`automount` programs to share :file:`/usr/local` between platforms + while having :file:`/usr/local/plat` be a different filesystem for each + platform. + + +.. cfunction:: char* Py_GetProgramFullPath() + + .. index:: + single: Py_SetProgramName() + single: executable (in module sys) + + Return the full program name of the Python executable; this is computed as a + side-effect of deriving the default module search path from the program name + (set by :cfunc:`Py_SetProgramName` above). The returned string points into + static storage; the caller should not modify its value. The value is available + to Python code as ``sys.executable``. + + +.. cfunction:: char* Py_GetPath() + + .. index:: + triple: module; search; path + single: path (in module sys) + + Return the default module search path; this is computed from the program name + (set by :cfunc:`Py_SetProgramName` above) and some environment variables. The + returned string consists of a series of directory names separated by a platform + dependent delimiter character. The delimiter character is ``':'`` on Unix and + Mac OS X, ``';'`` on Windows. The returned string points into static storage; + the caller should not modify its value. The value is available to Python code + as the list ``sys.path``, which may be modified to change the future search path + for loaded modules. + + .. % XXX should give the exact rules + + +.. cfunction:: const char* Py_GetVersion() + + Return the version of this Python interpreter. This is a string that looks + something like :: + + "1.5 (#67, Dec 31 1997, 22:34:28) [GCC 2.7.2.2]" + + .. index:: single: version (in module sys) + + The first word (up to the first space character) is the current Python version; + the first three characters are the major and minor version separated by a + period. The returned string points into static storage; the caller should not + modify its value. The value is available to Python code as ``sys.version``. + + +.. cfunction:: const char* Py_GetBuildNumber() + + Return a string representing the Subversion revision that this Python executable + was built from. This number is a string because it may contain a trailing 'M' + if Python was built from a mixed revision source tree. + + .. versionadded:: 2.5 + + +.. cfunction:: const char* Py_GetPlatform() + + .. index:: single: platform (in module sys) + + Return the platform identifier for the current platform. On Unix, this is + formed from the "official" name of the operating system, converted to lower + case, followed by the major revision number; e.g., for Solaris 2.x, which is + also known as SunOS 5.x, the value is ``'sunos5'``. On Mac OS X, it is + ``'darwin'``. On Windows, it is ``'win'``. The returned string points into + static storage; the caller should not modify its value. The value is available + to Python code as ``sys.platform``. + + +.. cfunction:: const char* Py_GetCopyright() + + Return the official copyright string for the current Python version, for example + + ``'Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam'`` + + .. index:: single: copyright (in module sys) + + The returned string points into static storage; the caller should not modify its + value. The value is available to Python code as ``sys.copyright``. + + +.. cfunction:: const char* Py_GetCompiler() + + Return an indication of the compiler used to build the current Python version, + in square brackets, for example:: + + "[GCC 2.7.2.2]" + + .. index:: single: version (in module sys) + + The returned string points into static storage; the caller should not modify its + value. The value is available to Python code as part of the variable + ``sys.version``. + + +.. cfunction:: const char* Py_GetBuildInfo() + + Return information about the sequence number and build date and time of the + current Python interpreter instance, for example :: + + "#67, Aug 1 1997, 22:34:28" + + .. index:: single: version (in module sys) + + The returned string points into static storage; the caller should not modify its + value. The value is available to Python code as part of the variable + ``sys.version``. + + +.. cfunction:: void PySys_SetArgv(int argc, char **argv) + + .. index:: + single: main() + single: Py_FatalError() + single: argv (in module sys) + + Set ``sys.argv`` based on *argc* and *argv*. These parameters are similar to + those passed to the program's :cfunc:`main` function with the difference that + the first entry should refer to the script file to be executed rather than the + executable hosting the Python interpreter. If there isn't a script that will be + run, the first entry in *argv* can be an empty string. If this function fails + to initialize ``sys.argv``, a fatal condition is signalled using + :cfunc:`Py_FatalError`. + + .. % XXX impl. doesn't seem consistent in allowing 0/NULL for the params; + .. % check w/ Guido. + +.. % XXX Other PySys thingies (doesn't really belong in this chapter) + + +.. _threads: + +Thread State and the Global Interpreter Lock +============================================ + +.. index:: + single: global interpreter lock + single: interpreter lock + single: lock, interpreter + +The Python interpreter is not fully thread safe. In order to support +multi-threaded Python programs, there's a global lock that must be held by the +current thread before it can safely access Python objects. Without the lock, +even the simplest operations could cause problems in a multi-threaded program: +for example, when two threads simultaneously increment the reference count of +the same object, the reference count could end up being incremented only once +instead of twice. + +.. index:: single: setcheckinterval() (in module sys) + +Therefore, the rule exists that only the thread that has acquired the global +interpreter lock may operate on Python objects or call Python/C API functions. +In order to support multi-threaded Python programs, the interpreter regularly +releases and reacquires the lock --- by default, every 100 bytecode instructions +(this can be changed with :func:`sys.setcheckinterval`). The lock is also +released and reacquired around potentially blocking I/O operations like reading +or writing a file, so that other threads can run while the thread that requests +the I/O is waiting for the I/O operation to complete. + +.. index:: + single: PyThreadState + single: PyThreadState + +The Python interpreter needs to keep some bookkeeping information separate per +thread --- for this it uses a data structure called :ctype:`PyThreadState`. +There's one global variable, however: the pointer to the current +:ctype:`PyThreadState` structure. While most thread packages have a way to +store "per-thread global data," Python's internal platform independent thread +abstraction doesn't support this yet. Therefore, the current thread state must +be manipulated explicitly. + +This is easy enough in most cases. Most code manipulating the global +interpreter lock has the following simple structure:: + + Save the thread state in a local variable. + Release the interpreter lock. + ...Do some blocking I/O operation... + Reacquire the interpreter lock. + Restore the thread state from the local variable. + +This is so common that a pair of macros exists to simplify it:: + + Py_BEGIN_ALLOW_THREADS + ...Do some blocking I/O operation... + Py_END_ALLOW_THREADS + +.. index:: + single: Py_BEGIN_ALLOW_THREADS + single: Py_END_ALLOW_THREADS + +The :cmacro:`Py_BEGIN_ALLOW_THREADS` macro opens a new block and declares a +hidden local variable; the :cmacro:`Py_END_ALLOW_THREADS` macro closes the +block. Another advantage of using these two macros is that when Python is +compiled without thread support, they are defined empty, thus saving the thread +state and lock manipulations. + +When thread support is enabled, the block above expands to the following code:: + + PyThreadState *_save; + + _save = PyEval_SaveThread(); + ...Do some blocking I/O operation... + PyEval_RestoreThread(_save); + +Using even lower level primitives, we can get roughly the same effect as +follows:: + + PyThreadState *_save; + + _save = PyThreadState_Swap(NULL); + PyEval_ReleaseLock(); + ...Do some blocking I/O operation... + PyEval_AcquireLock(); + PyThreadState_Swap(_save); + +.. index:: + single: PyEval_RestoreThread() + single: errno + single: PyEval_SaveThread() + single: PyEval_ReleaseLock() + single: PyEval_AcquireLock() + +There are some subtle differences; in particular, :cfunc:`PyEval_RestoreThread` +saves and restores the value of the global variable :cdata:`errno`, since the +lock manipulation does not guarantee that :cdata:`errno` is left alone. Also, +when thread support is disabled, :cfunc:`PyEval_SaveThread` and +:cfunc:`PyEval_RestoreThread` don't manipulate the lock; in this case, +:cfunc:`PyEval_ReleaseLock` and :cfunc:`PyEval_AcquireLock` are not available. +This is done so that dynamically loaded extensions compiled with thread support +enabled can be loaded by an interpreter that was compiled with disabled thread +support. + +The global interpreter lock is used to protect the pointer to the current thread +state. When releasing the lock and saving the thread state, the current thread +state pointer must be retrieved before the lock is released (since another +thread could immediately acquire the lock and store its own thread state in the +global variable). Conversely, when acquiring the lock and restoring the thread +state, the lock must be acquired before storing the thread state pointer. + +Why am I going on with so much detail about this? Because when threads are +created from C, they don't have the global interpreter lock, nor is there a +thread state data structure for them. Such threads must bootstrap themselves +into existence, by first creating a thread state data structure, then acquiring +the lock, and finally storing their thread state pointer, before they can start +using the Python/C API. When they are done, they should reset the thread state +pointer, release the lock, and finally free their thread state data structure. + +Beginning with version 2.3, threads can now take advantage of the +:cfunc:`PyGILState_\*` functions to do all of the above automatically. The +typical idiom for calling into Python from a C thread is now:: + + PyGILState_STATE gstate; + gstate = PyGILState_Ensure(); + + /* Perform Python actions here. */ + result = CallSomeFunction(); + /* evaluate result */ + + /* Release the thread. No Python API allowed beyond this point. */ + PyGILState_Release(gstate); + +Note that the :cfunc:`PyGILState_\*` functions assume there is only one global +interpreter (created automatically by :cfunc:`Py_Initialize`). Python still +supports the creation of additional interpreters (using +:cfunc:`Py_NewInterpreter`), but mixing multiple interpreters and the +:cfunc:`PyGILState_\*` API is unsupported. + + +.. ctype:: PyInterpreterState + + This data structure represents the state shared by a number of cooperating + threads. Threads belonging to the same interpreter share their module + administration and a few other internal items. There are no public members in + this structure. + + Threads belonging to different interpreters initially share nothing, except + process state like available memory, open file descriptors and such. The global + interpreter lock is also shared by all threads, regardless of to which + interpreter they belong. + + +.. ctype:: PyThreadState + + This data structure represents the state of a single thread. The only public + data member is :ctype:`PyInterpreterState \*`:attr:`interp`, which points to + this thread's interpreter state. + + +.. cfunction:: void PyEval_InitThreads() + + .. index:: + single: PyEval_ReleaseLock() + single: PyEval_ReleaseThread() + single: PyEval_SaveThread() + single: PyEval_RestoreThread() + + Initialize and acquire the global interpreter lock. It should be called in the + main thread before creating a second thread or engaging in any other thread + operations such as :cfunc:`PyEval_ReleaseLock` or + ``PyEval_ReleaseThread(tstate)``. It is not needed before calling + :cfunc:`PyEval_SaveThread` or :cfunc:`PyEval_RestoreThread`. + + .. index:: single: Py_Initialize() + + This is a no-op when called for a second time. It is safe to call this function + before calling :cfunc:`Py_Initialize`. + + .. index:: module: thread + + When only the main thread exists, no lock operations are needed. This is a + common situation (most Python programs do not use threads), and the lock + operations slow the interpreter down a bit. Therefore, the lock is not created + initially. This situation is equivalent to having acquired the lock: when + there is only a single thread, all object accesses are safe. Therefore, when + this function initializes the lock, it also acquires it. Before the Python + :mod:`thread` module creates a new thread, knowing that either it has the lock + or the lock hasn't been created yet, it calls :cfunc:`PyEval_InitThreads`. When + this call returns, it is guaranteed that the lock has been created and that the + calling thread has acquired it. + + It is **not** safe to call this function when it is unknown which thread (if + any) currently has the global interpreter lock. + + This function is not available when thread support is disabled at compile time. + + +.. cfunction:: int PyEval_ThreadsInitialized() + + Returns a non-zero value if :cfunc:`PyEval_InitThreads` has been called. This + function can be called without holding the lock, and therefore can be used to + avoid calls to the locking API when running single-threaded. This function is + not available when thread support is disabled at compile time. + + .. versionadded:: 2.4 + + +.. cfunction:: void PyEval_AcquireLock() + + Acquire the global interpreter lock. The lock must have been created earlier. + If this thread already has the lock, a deadlock ensues. This function is not + available when thread support is disabled at compile time. + + +.. cfunction:: void PyEval_ReleaseLock() + + Release the global interpreter lock. The lock must have been created earlier. + This function is not available when thread support is disabled at compile time. + + +.. cfunction:: void PyEval_AcquireThread(PyThreadState *tstate) + + Acquire the global interpreter lock and set the current thread state to + *tstate*, which should not be *NULL*. The lock must have been created earlier. + If this thread already has the lock, deadlock ensues. This function is not + available when thread support is disabled at compile time. + + +.. cfunction:: void PyEval_ReleaseThread(PyThreadState *tstate) + + Reset the current thread state to *NULL* and release the global interpreter + lock. The lock must have been created earlier and must be held by the current + thread. The *tstate* argument, which must not be *NULL*, is only used to check + that it represents the current thread state --- if it isn't, a fatal error is + reported. This function is not available when thread support is disabled at + compile time. + + +.. cfunction:: PyThreadState* PyEval_SaveThread() + + Release the interpreter lock (if it has been created and thread support is + enabled) and reset the thread state to *NULL*, returning the previous thread + state (which is not *NULL*). If the lock has been created, the current thread + must have acquired it. (This function is available even when thread support is + disabled at compile time.) + + +.. cfunction:: void PyEval_RestoreThread(PyThreadState *tstate) + + Acquire the interpreter lock (if it has been created and thread support is + enabled) and set the thread state to *tstate*, which must not be *NULL*. If the + lock has been created, the current thread must not have acquired it, otherwise + deadlock ensues. (This function is available even when thread support is + disabled at compile time.) + +The following macros are normally used without a trailing semicolon; look for +example usage in the Python source distribution. + + +.. cmacro:: Py_BEGIN_ALLOW_THREADS + + This macro expands to ``{ PyThreadState *_save; _save = PyEval_SaveThread();``. + Note that it contains an opening brace; it must be matched with a following + :cmacro:`Py_END_ALLOW_THREADS` macro. See above for further discussion of this + macro. It is a no-op when thread support is disabled at compile time. + + +.. cmacro:: Py_END_ALLOW_THREADS + + This macro expands to ``PyEval_RestoreThread(_save); }``. Note that it contains + a closing brace; it must be matched with an earlier + :cmacro:`Py_BEGIN_ALLOW_THREADS` macro. See above for further discussion of + this macro. It is a no-op when thread support is disabled at compile time. + + +.. cmacro:: Py_BLOCK_THREADS + + This macro expands to ``PyEval_RestoreThread(_save);``: it is equivalent to + :cmacro:`Py_END_ALLOW_THREADS` without the closing brace. It is a no-op when + thread support is disabled at compile time. + + +.. cmacro:: Py_UNBLOCK_THREADS + + This macro expands to ``_save = PyEval_SaveThread();``: it is equivalent to + :cmacro:`Py_BEGIN_ALLOW_THREADS` without the opening brace and variable + declaration. It is a no-op when thread support is disabled at compile time. + +All of the following functions are only available when thread support is enabled +at compile time, and must be called only when the interpreter lock has been +created. + + +.. cfunction:: PyInterpreterState* PyInterpreterState_New() + + Create a new interpreter state object. The interpreter lock need not be held, + but may be held if it is necessary to serialize calls to this function. + + +.. cfunction:: void PyInterpreterState_Clear(PyInterpreterState *interp) + + Reset all information in an interpreter state object. The interpreter lock must + be held. + + +.. cfunction:: void PyInterpreterState_Delete(PyInterpreterState *interp) + + Destroy an interpreter state object. The interpreter lock need not be held. + The interpreter state must have been reset with a previous call to + :cfunc:`PyInterpreterState_Clear`. + + +.. cfunction:: PyThreadState* PyThreadState_New(PyInterpreterState *interp) + + Create a new thread state object belonging to the given interpreter object. The + interpreter lock need not be held, but may be held if it is necessary to + serialize calls to this function. + + +.. cfunction:: void PyThreadState_Clear(PyThreadState *tstate) + + Reset all information in a thread state object. The interpreter lock must be + held. + + +.. cfunction:: void PyThreadState_Delete(PyThreadState *tstate) + + Destroy a thread state object. The interpreter lock need not be held. The + thread state must have been reset with a previous call to + :cfunc:`PyThreadState_Clear`. + + +.. cfunction:: PyThreadState* PyThreadState_Get() + + Return the current thread state. The interpreter lock must be held. When the + current thread state is *NULL*, this issues a fatal error (so that the caller + needn't check for *NULL*). + + +.. cfunction:: PyThreadState* PyThreadState_Swap(PyThreadState *tstate) + + Swap the current thread state with the thread state given by the argument + *tstate*, which may be *NULL*. The interpreter lock must be held. + + +.. cfunction:: PyObject* PyThreadState_GetDict() + + Return a dictionary in which extensions can store thread-specific state + information. Each extension should use a unique key to use to store state in + the dictionary. It is okay to call this function when no current thread state + is available. If this function returns *NULL*, no exception has been raised and + the caller should assume no current thread state is available. + + .. versionchanged:: 2.3 + Previously this could only be called when a current thread is active, and *NULL* + meant that an exception was raised. + + +.. cfunction:: int PyThreadState_SetAsyncExc(long id, PyObject *exc) + + Asynchronously raise an exception in a thread. The *id* argument is the thread + id of the target thread; *exc* is the exception object to be raised. This + function does not steal any references to *exc*. To prevent naive misuse, you + must write your own C extension to call this. Must be called with the GIL held. + Returns the number of thread states modified; this is normally one, but will be + zero if the thread id isn't found. If *exc* is :const:`NULL`, the pending + exception (if any) for the thread is cleared. This raises no exceptions. + + .. versionadded:: 2.3 + + +.. cfunction:: PyGILState_STATE PyGILState_Ensure() + + Ensure that the current thread is ready to call the Python C API regardless of + the current state of Python, or of its thread lock. This may be called as many + times as desired by a thread as long as each call is matched with a call to + :cfunc:`PyGILState_Release`. In general, other thread-related APIs may be used + between :cfunc:`PyGILState_Ensure` and :cfunc:`PyGILState_Release` calls as long + as the thread state is restored to its previous state before the Release(). For + example, normal usage of the :cmacro:`Py_BEGIN_ALLOW_THREADS` and + :cmacro:`Py_END_ALLOW_THREADS` macros is acceptable. + + The return value is an opaque "handle" to the thread state when + :cfunc:`PyGILState_Acquire` was called, and must be passed to + :cfunc:`PyGILState_Release` to ensure Python is left in the same state. Even + though recursive calls are allowed, these handles *cannot* be shared - each + unique call to :cfunc:`PyGILState_Ensure` must save the handle for its call to + :cfunc:`PyGILState_Release`. + + When the function returns, the current thread will hold the GIL. Failure is a + fatal error. + + .. versionadded:: 2.3 + + +.. cfunction:: void PyGILState_Release(PyGILState_STATE) + + Release any resources previously acquired. After this call, Python's state will + be the same as it was prior to the corresponding :cfunc:`PyGILState_Ensure` call + (but generally this state will be unknown to the caller, hence the use of the + GILState API.) + + Every call to :cfunc:`PyGILState_Ensure` must be matched by a call to + :cfunc:`PyGILState_Release` on the same thread. + + .. versionadded:: 2.3 + + +.. _profiling: + +Profiling and Tracing +===================== + +.. sectionauthor:: Fred L. Drake, Jr. + + +The Python interpreter provides some low-level support for attaching profiling +and execution tracing facilities. These are used for profiling, debugging, and +coverage analysis tools. + +Starting with Python 2.2, the implementation of this facility was substantially +revised, and an interface from C was added. This C interface allows the +profiling or tracing code to avoid the overhead of calling through Python-level +callable objects, making a direct C function call instead. The essential +attributes of the facility have not changed; the interface allows trace +functions to be installed per-thread, and the basic events reported to the trace +function are the same as had been reported to the Python-level trace functions +in previous versions. + + +.. ctype:: int (*Py_tracefunc)(PyObject *obj, PyFrameObject *frame, int what, PyObject *arg) + + The type of the trace function registered using :cfunc:`PyEval_SetProfile` and + :cfunc:`PyEval_SetTrace`. The first parameter is the object passed to the + registration function as *obj*, *frame* is the frame object to which the event + pertains, *what* is one of the constants :const:`PyTrace_CALL`, + :const:`PyTrace_EXCEPTION`, :const:`PyTrace_LINE`, :const:`PyTrace_RETURN`, + :const:`PyTrace_C_CALL`, :const:`PyTrace_C_EXCEPTION`, or + :const:`PyTrace_C_RETURN`, and *arg* depends on the value of *what*: + + +------------------------------+--------------------------------------+ + | Value of *what* | Meaning of *arg* | + +==============================+======================================+ + | :const:`PyTrace_CALL` | Always *NULL*. | + +------------------------------+--------------------------------------+ + | :const:`PyTrace_EXCEPTION` | Exception information as returned by | + | | :func:`sys.exc_info`. | + +------------------------------+--------------------------------------+ + | :const:`PyTrace_LINE` | Always *NULL*. | + +------------------------------+--------------------------------------+ + | :const:`PyTrace_RETURN` | Value being returned to the caller. | + +------------------------------+--------------------------------------+ + | :const:`PyTrace_C_CALL` | Name of function being called. | + +------------------------------+--------------------------------------+ + | :const:`PyTrace_C_EXCEPTION` | Always *NULL*. | + +------------------------------+--------------------------------------+ + | :const:`PyTrace_C_RETURN` | Always *NULL*. | + +------------------------------+--------------------------------------+ + + +.. cvar:: int PyTrace_CALL + + The value of the *what* parameter to a :ctype:`Py_tracefunc` function when a new + call to a function or method is being reported, or a new entry into a generator. + Note that the creation of the iterator for a generator function is not reported + as there is no control transfer to the Python bytecode in the corresponding + frame. + + +.. cvar:: int PyTrace_EXCEPTION + + The value of the *what* parameter to a :ctype:`Py_tracefunc` function when an + exception has been raised. The callback function is called with this value for + *what* when after any bytecode is processed after which the exception becomes + set within the frame being executed. The effect of this is that as exception + propagation causes the Python stack to unwind, the callback is called upon + return to each frame as the exception propagates. Only trace functions receives + these events; they are not needed by the profiler. + + +.. cvar:: int PyTrace_LINE + + The value passed as the *what* parameter to a trace function (but not a + profiling function) when a line-number event is being reported. + + +.. cvar:: int PyTrace_RETURN + + The value for the *what* parameter to :ctype:`Py_tracefunc` functions when a + call is returning without propagating an exception. + + +.. cvar:: int PyTrace_C_CALL + + The value for the *what* parameter to :ctype:`Py_tracefunc` functions when a C + function is about to be called. + + +.. cvar:: int PyTrace_C_EXCEPTION + + The value for the *what* parameter to :ctype:`Py_tracefunc` functions when a C + function has thrown an exception. + + +.. cvar:: int PyTrace_C_RETURN + + The value for the *what* parameter to :ctype:`Py_tracefunc` functions when a C + function has returned. + + +.. cfunction:: void PyEval_SetProfile(Py_tracefunc func, PyObject *obj) + + Set the profiler function to *func*. The *obj* parameter is passed to the + function as its first parameter, and may be any Python object, or *NULL*. If + the profile function needs to maintain state, using a different value for *obj* + for each thread provides a convenient and thread-safe place to store it. The + profile function is called for all monitored events except the line-number + events. + + +.. cfunction:: void PyEval_SetTrace(Py_tracefunc func, PyObject *obj) + + Set the tracing function to *func*. This is similar to + :cfunc:`PyEval_SetProfile`, except the tracing function does receive line-number + events. + + +.. _advanced-debugging: + +Advanced Debugger Support +========================= + +.. sectionauthor:: Fred L. Drake, Jr. + + +These functions are only intended to be used by advanced debugging tools. + + +.. cfunction:: PyInterpreterState* PyInterpreterState_Head() + + Return the interpreter state object at the head of the list of all such objects. + + .. versionadded:: 2.2 + + +.. cfunction:: PyInterpreterState* PyInterpreterState_Next(PyInterpreterState *interp) + + Return the next interpreter state object after *interp* from the list of all + such objects. + + .. versionadded:: 2.2 + + +.. cfunction:: PyThreadState * PyInterpreterState_ThreadHead(PyInterpreterState *interp) + + Return the a pointer to the first :ctype:`PyThreadState` object in the list of + threads associated with the interpreter *interp*. + + .. versionadded:: 2.2 + + +.. cfunction:: PyThreadState* PyThreadState_Next(PyThreadState *tstate) + + Return the next thread state object after *tstate* from the list of all such + objects belonging to the same :ctype:`PyInterpreterState` object. + + .. versionadded:: 2.2 + diff --git a/Doc/c-api/intro.rst b/Doc/c-api/intro.rst new file mode 100644 index 0000000..60b0052 --- /dev/null +++ b/Doc/c-api/intro.rst @@ -0,0 +1,630 @@ +.. highlightlang:: c + + +.. _api-intro: + +************ +Introduction +************ + +The Application Programmer's Interface to Python gives C and C++ programmers +access to the Python interpreter at a variety of levels. The API is equally +usable from C++, but for brevity it is generally referred to as the Python/C +API. There are two fundamentally different reasons for using the Python/C API. +The first reason is to write *extension modules* for specific purposes; these +are C modules that extend the Python interpreter. This is probably the most +common use. The second reason is to use Python as a component in a larger +application; this technique is generally referred to as :dfn:`embedding` Python +in an application. + +Writing an extension module is a relatively well-understood process, where a +"cookbook" approach works well. There are several tools that automate the +process to some extent. While people have embedded Python in other +applications since its early existence, the process of embedding Python is less +straightforward than writing an extension. + +Many API functions are useful independent of whether you're embedding or +extending Python; moreover, most applications that embed Python will need to +provide a custom extension as well, so it's probably a good idea to become +familiar with writing an extension before attempting to embed Python in a real +application. + + +.. _api-includes: + +Include Files +============= + +All function, type and macro definitions needed to use the Python/C API are +included in your code by the following line:: + + #include "Python.h" + +This implies inclusion of the following standard headers: ````, +````, ````, ````, and ```` (if +available). + +.. warning:: + + Since Python may define some pre-processor definitions which affect the standard + headers on some systems, you *must* include :file:`Python.h` before any standard + headers are included. + +All user visible names defined by Python.h (except those defined by the included +standard headers) have one of the prefixes ``Py`` or ``_Py``. Names beginning +with ``_Py`` are for internal use by the Python implementation and should not be +used by extension writers. Structure member names do not have a reserved prefix. + +**Important:** user code should never define names that begin with ``Py`` or +``_Py``. This confuses the reader, and jeopardizes the portability of the user +code to future Python versions, which may define additional names beginning with +one of these prefixes. + +The header files are typically installed with Python. On Unix, these are +located in the directories :file:`{prefix}/include/pythonversion/` and +:file:`{exec_prefix}/include/pythonversion/`, where :envvar:`prefix` and +:envvar:`exec_prefix` are defined by the corresponding parameters to Python's +:program:`configure` script and *version* is ``sys.version[:3]``. On Windows, +the headers are installed in :file:`{prefix}/include`, where :envvar:`prefix` is +the installation directory specified to the installer. + +To include the headers, place both directories (if different) on your compiler's +search path for includes. Do *not* place the parent directories on the search +path and then use ``#include ``; this will break on +multi-platform builds since the platform independent headers under +:envvar:`prefix` include the platform specific headers from +:envvar:`exec_prefix`. + +C++ users should note that though the API is defined entirely using C, the +header files do properly declare the entry points to be ``extern "C"``, so there +is no need to do anything special to use the API from C++. + + +.. _api-objects: + +Objects, Types and Reference Counts +=================================== + +.. index:: object: type + +Most Python/C API functions have one or more arguments as well as a return value +of type :ctype:`PyObject\*`. This type is a pointer to an opaque data type +representing an arbitrary Python object. Since all Python object types are +treated the same way by the Python language in most situations (e.g., +assignments, scope rules, and argument passing), it is only fitting that they +should be represented by a single C type. Almost all Python objects live on the +heap: you never declare an automatic or static variable of type +:ctype:`PyObject`, only pointer variables of type :ctype:`PyObject\*` can be +declared. The sole exception are the type objects; since these must never be +deallocated, they are typically static :ctype:`PyTypeObject` objects. + +All Python objects (even Python integers) have a :dfn:`type` and a +:dfn:`reference count`. An object's type determines what kind of object it is +(e.g., an integer, a list, or a user-defined function; there are many more as +explained in :ref:`types`). For each of the well-known types there is a macro +to check whether an object is of that type; for instance, ``PyList_Check(a)`` is +true if (and only if) the object pointed to by *a* is a Python list. + + +.. _api-refcounts: + +Reference Counts +---------------- + +The reference count is important because today's computers have a finite (and +often severely limited) memory size; it counts how many different places there +are that have a reference to an object. Such a place could be another object, +or a global (or static) C variable, or a local variable in some C function. +When an object's reference count becomes zero, the object is deallocated. If +it contains references to other objects, their reference count is decremented. +Those other objects may be deallocated in turn, if this decrement makes their +reference count become zero, and so on. (There's an obvious problem with +objects that reference each other here; for now, the solution is "don't do +that.") + +.. index:: + single: Py_INCREF() + single: Py_DECREF() + +Reference counts are always manipulated explicitly. The normal way is to use +the macro :cfunc:`Py_INCREF` to increment an object's reference count by one, +and :cfunc:`Py_DECREF` to decrement it by one. The :cfunc:`Py_DECREF` macro +is considerably more complex than the incref one, since it must check whether +the reference count becomes zero and then cause the object's deallocator to be +called. The deallocator is a function pointer contained in the object's type +structure. The type-specific deallocator takes care of decrementing the +reference counts for other objects contained in the object if this is a compound +object type, such as a list, as well as performing any additional finalization +that's needed. There's no chance that the reference count can overflow; at +least as many bits are used to hold the reference count as there are distinct +memory locations in virtual memory (assuming ``sizeof(long) >= sizeof(char*)``). +Thus, the reference count increment is a simple operation. + +It is not necessary to increment an object's reference count for every local +variable that contains a pointer to an object. In theory, the object's +reference count goes up by one when the variable is made to point to it and it +goes down by one when the variable goes out of scope. However, these two +cancel each other out, so at the end the reference count hasn't changed. The +only real reason to use the reference count is to prevent the object from being +deallocated as long as our variable is pointing to it. If we know that there +is at least one other reference to the object that lives at least as long as +our variable, there is no need to increment the reference count temporarily. +An important situation where this arises is in objects that are passed as +arguments to C functions in an extension module that are called from Python; +the call mechanism guarantees to hold a reference to every argument for the +duration of the call. + +However, a common pitfall is to extract an object from a list and hold on to it +for a while without incrementing its reference count. Some other operation might +conceivably remove the object from the list, decrementing its reference count +and possible deallocating it. The real danger is that innocent-looking +operations may invoke arbitrary Python code which could do this; there is a code +path which allows control to flow back to the user from a :cfunc:`Py_DECREF`, so +almost any operation is potentially dangerous. + +A safe approach is to always use the generic operations (functions whose name +begins with ``PyObject_``, ``PyNumber_``, ``PySequence_`` or ``PyMapping_``). +These operations always increment the reference count of the object they return. +This leaves the caller with the responsibility to call :cfunc:`Py_DECREF` when +they are done with the result; this soon becomes second nature. + + +.. _api-refcountdetails: + +Reference Count Details +^^^^^^^^^^^^^^^^^^^^^^^ + +The reference count behavior of functions in the Python/C API is best explained +in terms of *ownership of references*. Ownership pertains to references, never +to objects (objects are not owned: they are always shared). "Owning a +reference" means being responsible for calling Py_DECREF on it when the +reference is no longer needed. Ownership can also be transferred, meaning that +the code that receives ownership of the reference then becomes responsible for +eventually decref'ing it by calling :cfunc:`Py_DECREF` or :cfunc:`Py_XDECREF` +when it's no longer needed---or passing on this responsibility (usually to its +caller). When a function passes ownership of a reference on to its caller, the +caller is said to receive a *new* reference. When no ownership is transferred, +the caller is said to *borrow* the reference. Nothing needs to be done for a +borrowed reference. + +Conversely, when a calling function passes it a reference to an object, there +are two possibilities: the function *steals* a reference to the object, or it +does not. *Stealing a reference* means that when you pass a reference to a +function, that function assumes that it now owns that reference, and you are not +responsible for it any longer. + +.. index:: + single: PyList_SetItem() + single: PyTuple_SetItem() + +Few functions steal references; the two notable exceptions are +:cfunc:`PyList_SetItem` and :cfunc:`PyTuple_SetItem`, which steal a reference +to the item (but not to the tuple or list into which the item is put!). These +functions were designed to steal a reference because of a common idiom for +populating a tuple or list with newly created objects; for example, the code to +create the tuple ``(1, 2, "three")`` could look like this (forgetting about +error handling for the moment; a better way to code this is shown below):: + + PyObject *t; + + t = PyTuple_New(3); + PyTuple_SetItem(t, 0, PyInt_FromLong(1L)); + PyTuple_SetItem(t, 1, PyInt_FromLong(2L)); + PyTuple_SetItem(t, 2, PyString_FromString("three")); + +Here, :cfunc:`PyInt_FromLong` returns a new reference which is immediately +stolen by :cfunc:`PyTuple_SetItem`. When you want to keep using an object +although the reference to it will be stolen, use :cfunc:`Py_INCREF` to grab +another reference before calling the reference-stealing function. + +Incidentally, :cfunc:`PyTuple_SetItem` is the *only* way to set tuple items; +:cfunc:`PySequence_SetItem` and :cfunc:`PyObject_SetItem` refuse to do this +since tuples are an immutable data type. You should only use +:cfunc:`PyTuple_SetItem` for tuples that you are creating yourself. + +Equivalent code for populating a list can be written using :cfunc:`PyList_New` +and :cfunc:`PyList_SetItem`. + +However, in practice, you will rarely use these ways of creating and populating +a tuple or list. There's a generic function, :cfunc:`Py_BuildValue`, that can +create most common objects from C values, directed by a :dfn:`format string`. +For example, the above two blocks of code could be replaced by the following +(which also takes care of the error checking):: + + PyObject *tuple, *list; + + tuple = Py_BuildValue("(iis)", 1, 2, "three"); + list = Py_BuildValue("[iis]", 1, 2, "three"); + +It is much more common to use :cfunc:`PyObject_SetItem` and friends with items +whose references you are only borrowing, like arguments that were passed in to +the function you are writing. In that case, their behaviour regarding reference +counts is much saner, since you don't have to increment a reference count so you +can give a reference away ("have it be stolen"). For example, this function +sets all items of a list (actually, any mutable sequence) to a given item:: + + int + set_all(PyObject *target, PyObject *item) + { + int i, n; + + n = PyObject_Length(target); + if (n < 0) + return -1; + for (i = 0; i < n; i++) { + PyObject *index = PyInt_FromLong(i); + if (!index) + return -1; + if (PyObject_SetItem(target, index, item) < 0) + return -1; + Py_DECREF(index); + } + return 0; + } + +.. index:: single: set_all() + +The situation is slightly different for function return values. While passing +a reference to most functions does not change your ownership responsibilities +for that reference, many functions that return a reference to an object give +you ownership of the reference. The reason is simple: in many cases, the +returned object is created on the fly, and the reference you get is the only +reference to the object. Therefore, the generic functions that return object +references, like :cfunc:`PyObject_GetItem` and :cfunc:`PySequence_GetItem`, +always return a new reference (the caller becomes the owner of the reference). + +It is important to realize that whether you own a reference returned by a +function depends on which function you call only --- *the plumage* (the type of +the object passed as an argument to the function) *doesn't enter into it!* +Thus, if you extract an item from a list using :cfunc:`PyList_GetItem`, you +don't own the reference --- but if you obtain the same item from the same list +using :cfunc:`PySequence_GetItem` (which happens to take exactly the same +arguments), you do own a reference to the returned object. + +.. index:: + single: PyList_GetItem() + single: PySequence_GetItem() + +Here is an example of how you could write a function that computes the sum of +the items in a list of integers; once using :cfunc:`PyList_GetItem`, and once +using :cfunc:`PySequence_GetItem`. :: + + long + sum_list(PyObject *list) + { + int i, n; + long total = 0; + PyObject *item; + + n = PyList_Size(list); + if (n < 0) + return -1; /* Not a list */ + for (i = 0; i < n; i++) { + item = PyList_GetItem(list, i); /* Can't fail */ + if (!PyInt_Check(item)) continue; /* Skip non-integers */ + total += PyInt_AsLong(item); + } + return total; + } + +.. index:: single: sum_list() + +:: + + long + sum_sequence(PyObject *sequence) + { + int i, n; + long total = 0; + PyObject *item; + n = PySequence_Length(sequence); + if (n < 0) + return -1; /* Has no length */ + for (i = 0; i < n; i++) { + item = PySequence_GetItem(sequence, i); + if (item == NULL) + return -1; /* Not a sequence, or other failure */ + if (PyInt_Check(item)) + total += PyInt_AsLong(item); + Py_DECREF(item); /* Discard reference ownership */ + } + return total; + } + +.. index:: single: sum_sequence() + + +.. _api-types: + +Types +----- + +There are few other data types that play a significant role in the Python/C +API; most are simple C types such as :ctype:`int`, :ctype:`long`, +:ctype:`double` and :ctype:`char\*`. A few structure types are used to +describe static tables used to list the functions exported by a module or the +data attributes of a new object type, and another is used to describe the value +of a complex number. These will be discussed together with the functions that +use them. + + +.. _api-exceptions: + +Exceptions +========== + +The Python programmer only needs to deal with exceptions if specific error +handling is required; unhandled exceptions are automatically propagated to the +caller, then to the caller's caller, and so on, until they reach the top-level +interpreter, where they are reported to the user accompanied by a stack +traceback. + +.. index:: single: PyErr_Occurred() + +For C programmers, however, error checking always has to be explicit. All +functions in the Python/C API can raise exceptions, unless an explicit claim is +made otherwise in a function's documentation. In general, when a function +encounters an error, it sets an exception, discards any object references that +it owns, and returns an error indicator --- usually *NULL* or ``-1``. A few +functions return a Boolean true/false result, with false indicating an error. +Very few functions return no explicit error indicator or have an ambiguous +return value, and require explicit testing for errors with +:cfunc:`PyErr_Occurred`. + +.. index:: + single: PyErr_SetString() + single: PyErr_Clear() + +Exception state is maintained in per-thread storage (this is equivalent to +using global storage in an unthreaded application). A thread can be in one of +two states: an exception has occurred, or not. The function +:cfunc:`PyErr_Occurred` can be used to check for this: it returns a borrowed +reference to the exception type object when an exception has occurred, and +*NULL* otherwise. There are a number of functions to set the exception state: +:cfunc:`PyErr_SetString` is the most common (though not the most general) +function to set the exception state, and :cfunc:`PyErr_Clear` clears the +exception state. + +The full exception state consists of three objects (all of which can be +*NULL*): the exception type, the corresponding exception value, and the +traceback. These have the same meanings as the Python result of +``sys.exc_info()``; however, they are not the same: the Python objects represent +the last exception being handled by a Python :keyword:`try` ... +:keyword:`except` statement, while the C level exception state only exists while +an exception is being passed on between C functions until it reaches the Python +bytecode interpreter's main loop, which takes care of transferring it to +``sys.exc_info()`` and friends. + +.. index:: single: exc_info() (in module sys) + +Note that starting with Python 1.5, the preferred, thread-safe way to access the +exception state from Python code is to call the function :func:`sys.exc_info`, +which returns the per-thread exception state for Python code. Also, the +semantics of both ways to access the exception state have changed so that a +function which catches an exception will save and restore its thread's exception +state so as to preserve the exception state of its caller. This prevents common +bugs in exception handling code caused by an innocent-looking function +overwriting the exception being handled; it also reduces the often unwanted +lifetime extension for objects that are referenced by the stack frames in the +traceback. + +As a general principle, a function that calls another function to perform some +task should check whether the called function raised an exception, and if so, +pass the exception state on to its caller. It should discard any object +references that it owns, and return an error indicator, but it should *not* set +another exception --- that would overwrite the exception that was just raised, +and lose important information about the exact cause of the error. + +.. index:: single: sum_sequence() + +A simple example of detecting exceptions and passing them on is shown in the +:cfunc:`sum_sequence` example above. It so happens that that example doesn't +need to clean up any owned references when it detects an error. The following +example function shows some error cleanup. First, to remind you why you like +Python, we show the equivalent Python code:: + + def incr_item(dict, key): + try: + item = dict[key] + except KeyError: + item = 0 + dict[key] = item + 1 + +.. index:: single: incr_item() + +Here is the corresponding C code, in all its glory:: + + int + incr_item(PyObject *dict, PyObject *key) + { + /* Objects all initialized to NULL for Py_XDECREF */ + PyObject *item = NULL, *const_one = NULL, *incremented_item = NULL; + int rv = -1; /* Return value initialized to -1 (failure) */ + + item = PyObject_GetItem(dict, key); + if (item == NULL) { + /* Handle KeyError only: */ + if (!PyErr_ExceptionMatches(PyExc_KeyError)) + goto error; + + /* Clear the error and use zero: */ + PyErr_Clear(); + item = PyInt_FromLong(0L); + if (item == NULL) + goto error; + } + const_one = PyInt_FromLong(1L); + if (const_one == NULL) + goto error; + + incremented_item = PyNumber_Add(item, const_one); + if (incremented_item == NULL) + goto error; + + if (PyObject_SetItem(dict, key, incremented_item) < 0) + goto error; + rv = 0; /* Success */ + /* Continue with cleanup code */ + + error: + /* Cleanup code, shared by success and failure path */ + + /* Use Py_XDECREF() to ignore NULL references */ + Py_XDECREF(item); + Py_XDECREF(const_one); + Py_XDECREF(incremented_item); + + return rv; /* -1 for error, 0 for success */ + } + +.. index:: single: incr_item() + +.. index:: + single: PyErr_ExceptionMatches() + single: PyErr_Clear() + single: Py_XDECREF() + +This example represents an endorsed use of the :keyword:`goto` statement in C! +It illustrates the use of :cfunc:`PyErr_ExceptionMatches` and +:cfunc:`PyErr_Clear` to handle specific exceptions, and the use of +:cfunc:`Py_XDECREF` to dispose of owned references that may be *NULL* (note the +``'X'`` in the name; :cfunc:`Py_DECREF` would crash when confronted with a +*NULL* reference). It is important that the variables used to hold owned +references are initialized to *NULL* for this to work; likewise, the proposed +return value is initialized to ``-1`` (failure) and only set to success after +the final call made is successful. + + +.. _api-embedding: + +Embedding Python +================ + +The one important task that only embedders (as opposed to extension writers) of +the Python interpreter have to worry about is the initialization, and possibly +the finalization, of the Python interpreter. Most functionality of the +interpreter can only be used after the interpreter has been initialized. + +.. index:: + single: Py_Initialize() + module: __builtin__ + module: __main__ + module: sys + module: exceptions + triple: module; search; path + single: path (in module sys) + +The basic initialization function is :cfunc:`Py_Initialize`. This initializes +the table of loaded modules, and creates the fundamental modules +:mod:`__builtin__`, :mod:`__main__`, :mod:`sys`, and :mod:`exceptions`. It also +initializes the module search path (``sys.path``). + +.. index:: single: PySys_SetArgv() + +:cfunc:`Py_Initialize` does not set the "script argument list" (``sys.argv``). +If this variable is needed by Python code that will be executed later, it must +be set explicitly with a call to ``PySys_SetArgv(argc, argv)`` subsequent to +the call to :cfunc:`Py_Initialize`. + +On most systems (in particular, on Unix and Windows, although the details are +slightly different), :cfunc:`Py_Initialize` calculates the module search path +based upon its best guess for the location of the standard Python interpreter +executable, assuming that the Python library is found in a fixed location +relative to the Python interpreter executable. In particular, it looks for a +directory named :file:`lib/python{X.Y}` relative to the parent directory +where the executable named :file:`python` is found on the shell command search +path (the environment variable :envvar:`PATH`). + +For instance, if the Python executable is found in +:file:`/usr/local/bin/python`, it will assume that the libraries are in +:file:`/usr/local/lib/python{X.Y}`. (In fact, this particular path is also +the "fallback" location, used when no executable file named :file:`python` is +found along :envvar:`PATH`.) The user can override this behavior by setting the +environment variable :envvar:`PYTHONHOME`, or insert additional directories in +front of the standard path by setting :envvar:`PYTHONPATH`. + +.. index:: + single: Py_SetProgramName() + single: Py_GetPath() + single: Py_GetPrefix() + single: Py_GetExecPrefix() + single: Py_GetProgramFullPath() + +The embedding application can steer the search by calling +``Py_SetProgramName(file)`` *before* calling :cfunc:`Py_Initialize`. Note that +:envvar:`PYTHONHOME` still overrides this and :envvar:`PYTHONPATH` is still +inserted in front of the standard path. An application that requires total +control has to provide its own implementation of :cfunc:`Py_GetPath`, +:cfunc:`Py_GetPrefix`, :cfunc:`Py_GetExecPrefix`, and +:cfunc:`Py_GetProgramFullPath` (all defined in :file:`Modules/getpath.c`). + +.. index:: single: Py_IsInitialized() + +Sometimes, it is desirable to "uninitialize" Python. For instance, the +application may want to start over (make another call to +:cfunc:`Py_Initialize`) or the application is simply done with its use of +Python and wants to free memory allocated by Python. This can be accomplished +by calling :cfunc:`Py_Finalize`. The function :cfunc:`Py_IsInitialized` returns +true if Python is currently in the initialized state. More information about +these functions is given in a later chapter. Notice that :cfunc:`Py_Finalize` +does *not* free all memory allocated by the Python interpreter, e.g. memory +allocated by extension modules currently cannot be released. + + +.. _api-debugging: + +Debugging Builds +================ + +Python can be built with several macros to enable extra checks of the +interpreter and extension modules. These checks tend to add a large amount of +overhead to the runtime so they are not enabled by default. + +A full list of the various types of debugging builds is in the file +:file:`Misc/SpecialBuilds.txt` in the Python source distribution. Builds are +available that support tracing of reference counts, debugging the memory +allocator, or low-level profiling of the main interpreter loop. Only the most +frequently-used builds will be described in the remainder of this section. + +Compiling the interpreter with the :cmacro:`Py_DEBUG` macro defined produces +what is generally meant by "a debug build" of Python. :cmacro:`Py_DEBUG` is +enabled in the Unix build by adding :option:`--with-pydebug` to the +:file:`configure` command. It is also implied by the presence of the +not-Python-specific :cmacro:`_DEBUG` macro. When :cmacro:`Py_DEBUG` is enabled +in the Unix build, compiler optimization is disabled. + +In addition to the reference count debugging described below, the following +extra checks are performed: + +* Extra checks are added to the object allocator. + +* Extra checks are added to the parser and compiler. + +* Downcasts from wide types to narrow types are checked for loss of information. + +* A number of assertions are added to the dictionary and set implementations. + In addition, the set object acquires a :meth:`test_c_api` method. + +* Sanity checks of the input arguments are added to frame creation. + +* The storage for long ints is initialized with a known invalid pattern to catch + reference to uninitialized digits. + +* Low-level tracing and extra exception checking are added to the runtime + virtual machine. + +* Extra checks are added to the memory arena implementation. + +* Extra debugging is added to the thread module. + +There may be additional checks not mentioned here. + +Defining :cmacro:`Py_TRACE_REFS` enables reference tracing. When defined, a +circular doubly linked list of active objects is maintained by adding two extra +fields to every :ctype:`PyObject`. Total allocations are tracked as well. Upon +exit, all existing references are printed. (In interactive mode this happens +after every statement run by the interpreter.) Implied by :cmacro:`Py_DEBUG`. + +Please refer to :file:`Misc/SpecialBuilds.txt` in the Python source distribution +for more detailed information. + diff --git a/Doc/c-api/memory.rst b/Doc/c-api/memory.rst new file mode 100644 index 0000000..1dcb115 --- /dev/null +++ b/Doc/c-api/memory.rst @@ -0,0 +1,207 @@ +.. highlightlang:: c + + +.. _memory: + +***************** +Memory Management +***************** + +.. sectionauthor:: Vladimir Marangozov + + + +.. _memoryoverview: + +Overview +======== + +Memory management in Python involves a private heap containing all Python +objects and data structures. The management of this private heap is ensured +internally by the *Python memory manager*. The Python memory manager has +different components which deal with various dynamic storage management aspects, +like sharing, segmentation, preallocation or caching. + +At the lowest level, a raw memory allocator ensures that there is enough room in +the private heap for storing all Python-related data by interacting with the +memory manager of the operating system. On top of the raw memory allocator, +several object-specific allocators operate on the same heap and implement +distinct memory management policies adapted to the peculiarities of every object +type. For example, integer objects are managed differently within the heap than +strings, tuples or dictionaries because integers imply different storage +requirements and speed/space tradeoffs. The Python memory manager thus delegates +some of the work to the object-specific allocators, but ensures that the latter +operate within the bounds of the private heap. + +It is important to understand that the management of the Python heap is +performed by the interpreter itself and that the user has no control over it, +even if she regularly manipulates object pointers to memory blocks inside that +heap. The allocation of heap space for Python objects and other internal +buffers is performed on demand by the Python memory manager through the Python/C +API functions listed in this document. + +.. index:: + single: malloc() + single: calloc() + single: realloc() + single: free() + +To avoid memory corruption, extension writers should never try to operate on +Python objects with the functions exported by the C library: :cfunc:`malloc`, +:cfunc:`calloc`, :cfunc:`realloc` and :cfunc:`free`. This will result in mixed +calls between the C allocator and the Python memory manager with fatal +consequences, because they implement different algorithms and operate on +different heaps. However, one may safely allocate and release memory blocks +with the C library allocator for individual purposes, as shown in the following +example:: + + PyObject *res; + char *buf = (char *) malloc(BUFSIZ); /* for I/O */ + + if (buf == NULL) + return PyErr_NoMemory(); + ...Do some I/O operation involving buf... + res = PyString_FromString(buf); + free(buf); /* malloc'ed */ + return res; + +In this example, the memory request for the I/O buffer is handled by the C +library allocator. The Python memory manager is involved only in the allocation +of the string object returned as a result. + +In most situations, however, it is recommended to allocate memory from the +Python heap specifically because the latter is under control of the Python +memory manager. For example, this is required when the interpreter is extended +with new object types written in C. Another reason for using the Python heap is +the desire to *inform* the Python memory manager about the memory needs of the +extension module. Even when the requested memory is used exclusively for +internal, highly-specific purposes, delegating all memory requests to the Python +memory manager causes the interpreter to have a more accurate image of its +memory footprint as a whole. Consequently, under certain circumstances, the +Python memory manager may or may not trigger appropriate actions, like garbage +collection, memory compaction or other preventive procedures. Note that by using +the C library allocator as shown in the previous example, the allocated memory +for the I/O buffer escapes completely the Python memory manager. + + +.. _memoryinterface: + +Memory Interface +================ + +The following function sets, modeled after the ANSI C standard, but specifying +behavior when requesting zero bytes, are available for allocating and releasing +memory from the Python heap: + + +.. cfunction:: void* PyMem_Malloc(size_t n) + + Allocates *n* bytes and returns a pointer of type :ctype:`void\*` to the + allocated memory, or *NULL* if the request fails. Requesting zero bytes returns + a distinct non-*NULL* pointer if possible, as if :cfunc:`PyMem_Malloc(1)` had + been called instead. The memory will not have been initialized in any way. + + +.. cfunction:: void* PyMem_Realloc(void *p, size_t n) + + Resizes the memory block pointed to by *p* to *n* bytes. The contents will be + unchanged to the minimum of the old and the new sizes. If *p* is *NULL*, the + call is equivalent to :cfunc:`PyMem_Malloc(n)`; else if *n* is equal to zero, + the memory block is resized but is not freed, and the returned pointer is + non-*NULL*. Unless *p* is *NULL*, it must have been returned by a previous call + to :cfunc:`PyMem_Malloc` or :cfunc:`PyMem_Realloc`. If the request fails, + :cfunc:`PyMem_Realloc` returns *NULL* and *p* remains a valid pointer to the + previous memory area. + + +.. cfunction:: void PyMem_Free(void *p) + + Frees the memory block pointed to by *p*, which must have been returned by a + previous call to :cfunc:`PyMem_Malloc` or :cfunc:`PyMem_Realloc`. Otherwise, or + if :cfunc:`PyMem_Free(p)` has been called before, undefined behavior occurs. If + *p* is *NULL*, no operation is performed. + +The following type-oriented macros are provided for convenience. Note that +*TYPE* refers to any C type. + + +.. cfunction:: TYPE* PyMem_New(TYPE, size_t n) + + Same as :cfunc:`PyMem_Malloc`, but allocates ``(n * sizeof(TYPE))`` bytes of + memory. Returns a pointer cast to :ctype:`TYPE\*`. The memory will not have + been initialized in any way. + + +.. cfunction:: TYPE* PyMem_Resize(void *p, TYPE, size_t n) + + Same as :cfunc:`PyMem_Realloc`, but the memory block is resized to ``(n * + sizeof(TYPE))`` bytes. Returns a pointer cast to :ctype:`TYPE\*`. On return, + *p* will be a pointer to the new memory area, or *NULL* in the event of failure. + + +.. cfunction:: void PyMem_Del(void *p) + + Same as :cfunc:`PyMem_Free`. + +In addition, the following macro sets are provided for calling the Python memory +allocator directly, without involving the C API functions listed above. However, +note that their use does not preserve binary compatibility across Python +versions and is therefore deprecated in extension modules. + +:cfunc:`PyMem_MALLOC`, :cfunc:`PyMem_REALLOC`, :cfunc:`PyMem_FREE`. + +:cfunc:`PyMem_NEW`, :cfunc:`PyMem_RESIZE`, :cfunc:`PyMem_DEL`. + + +.. _memoryexamples: + +Examples +======== + +Here is the example from section :ref:`memoryoverview`, rewritten so that the +I/O buffer is allocated from the Python heap by using the first function set:: + + PyObject *res; + char *buf = (char *) PyMem_Malloc(BUFSIZ); /* for I/O */ + + if (buf == NULL) + return PyErr_NoMemory(); + /* ...Do some I/O operation involving buf... */ + res = PyString_FromString(buf); + PyMem_Free(buf); /* allocated with PyMem_Malloc */ + return res; + +The same code using the type-oriented function set:: + + PyObject *res; + char *buf = PyMem_New(char, BUFSIZ); /* for I/O */ + + if (buf == NULL) + return PyErr_NoMemory(); + /* ...Do some I/O operation involving buf... */ + res = PyString_FromString(buf); + PyMem_Del(buf); /* allocated with PyMem_New */ + return res; + +Note that in the two examples above, the buffer is always manipulated via +functions belonging to the same set. Indeed, it is required to use the same +memory API family for a given memory block, so that the risk of mixing different +allocators is reduced to a minimum. The following code sequence contains two +errors, one of which is labeled as *fatal* because it mixes two different +allocators operating on different heaps. :: + + char *buf1 = PyMem_New(char, BUFSIZ); + char *buf2 = (char *) malloc(BUFSIZ); + char *buf3 = (char *) PyMem_Malloc(BUFSIZ); + ... + PyMem_Del(buf3); /* Wrong -- should be PyMem_Free() */ + free(buf2); /* Right -- allocated via malloc() */ + free(buf1); /* Fatal -- should be PyMem_Del() */ + +In addition to the functions aimed at handling raw memory blocks from the Python +heap, objects in Python are allocated and released with :cfunc:`PyObject_New`, +:cfunc:`PyObject_NewVar` and :cfunc:`PyObject_Del`. + +These will be explained in the next chapter on defining and implementing new +object types in C. + diff --git a/Doc/c-api/newtypes.rst b/Doc/c-api/newtypes.rst new file mode 100644 index 0000000..5933f99 --- /dev/null +++ b/Doc/c-api/newtypes.rst @@ -0,0 +1,1740 @@ +.. highlightlang:: c + + +.. _newtypes: + +***************************** +Object Implementation Support +***************************** + +This chapter describes the functions, types, and macros used when defining new +object types. + + +.. _allocating-objects: + +Allocating Objects on the Heap +============================== + + +.. cfunction:: PyObject* _PyObject_New(PyTypeObject *type) + + +.. cfunction:: PyVarObject* _PyObject_NewVar(PyTypeObject *type, Py_ssize_t size) + + +.. cfunction:: void _PyObject_Del(PyObject *op) + + +.. cfunction:: PyObject* PyObject_Init(PyObject *op, PyTypeObject *type) + + Initialize a newly-allocated object *op* with its type and initial reference. + Returns the initialized object. If *type* indicates that the object + participates in the cyclic garbage detector, it is added to the detector's set + of observed objects. Other fields of the object are not affected. + + +.. cfunction:: PyVarObject* PyObject_InitVar(PyVarObject *op, PyTypeObject *type, Py_ssize_t size) + + This does everything :cfunc:`PyObject_Init` does, and also initializes the + length information for a variable-size object. + + +.. cfunction:: TYPE* PyObject_New(TYPE, PyTypeObject *type) + + Allocate a new Python object using the C structure type *TYPE* and the Python + type object *type*. Fields not defined by the Python object header are not + initialized; the object's reference count will be one. The size of the memory + allocation is determined from the :attr:`tp_basicsize` field of the type object. + + +.. cfunction:: TYPE* PyObject_NewVar(TYPE, PyTypeObject *type, Py_ssize_t size) + + Allocate a new Python object using the C structure type *TYPE* and the Python + type object *type*. Fields not defined by the Python object header are not + initialized. The allocated memory allows for the *TYPE* structure plus *size* + fields of the size given by the :attr:`tp_itemsize` field of *type*. This is + useful for implementing objects like tuples, which are able to determine their + size at construction time. Embedding the array of fields into the same + allocation decreases the number of allocations, improving the memory management + efficiency. + + +.. cfunction:: void PyObject_Del(PyObject *op) + + Releases memory allocated to an object using :cfunc:`PyObject_New` or + :cfunc:`PyObject_NewVar`. This is normally called from the :attr:`tp_dealloc` + handler specified in the object's type. The fields of the object should not be + accessed after this call as the memory is no longer a valid Python object. + + +.. cfunction:: PyObject* Py_InitModule(char *name, PyMethodDef *methods) + + Create a new module object based on a name and table of functions, returning the + new module object. + + .. versionchanged:: 2.3 + Older versions of Python did not support *NULL* as the value for the *methods* + argument. + + +.. cfunction:: PyObject* Py_InitModule3(char *name, PyMethodDef *methods, char *doc) + + Create a new module object based on a name and table of functions, returning the + new module object. If *doc* is non-*NULL*, it will be used to define the + docstring for the module. + + .. versionchanged:: 2.3 + Older versions of Python did not support *NULL* as the value for the *methods* + argument. + + +.. cfunction:: PyObject* Py_InitModule4(char *name, PyMethodDef *methods, char *doc, PyObject *self, int apiver) + + Create a new module object based on a name and table of functions, returning the + new module object. If *doc* is non-*NULL*, it will be used to define the + docstring for the module. If *self* is non-*NULL*, it will passed to the + functions of the module as their (otherwise *NULL*) first parameter. (This was + added as an experimental feature, and there are no known uses in the current + version of Python.) For *apiver*, the only value which should be passed is + defined by the constant :const:`PYTHON_API_VERSION`. + + .. note:: + + Most uses of this function should probably be using the :cfunc:`Py_InitModule3` + instead; only use this if you are sure you need it. + + .. versionchanged:: 2.3 + Older versions of Python did not support *NULL* as the value for the *methods* + argument. + + +.. cvar:: PyObject _Py_NoneStruct + + Object which is visible in Python as ``None``. This should only be accessed + using the ``Py_None`` macro, which evaluates to a pointer to this object. + + +.. _common-structs: + +Common Object Structures +======================== + +There are a large number of structures which are used in the definition of +object types for Python. This section describes these structures and how they +are used. + +All Python objects ultimately share a small number of fields at the beginning of +the object's representation in memory. These are represented by the +:ctype:`PyObject` and :ctype:`PyVarObject` types, which are defined, in turn, by +the expansions of some macros also used, whether directly or indirectly, in the +definition of all other Python objects. + + +.. ctype:: PyObject + + All object types are extensions of this type. This is a type which contains the + information Python needs to treat a pointer to an object as an object. In a + normal "release" build, it contains only the objects reference count and a + pointer to the corresponding type object. It corresponds to the fields defined + by the expansion of the ``PyObject_HEAD`` macro. + + +.. ctype:: PyVarObject + + This is an extension of :ctype:`PyObject` that adds the :attr:`ob_size` field. + This is only used for objects that have some notion of *length*. This type does + not often appear in the Python/C API. It corresponds to the fields defined by + the expansion of the ``PyObject_VAR_HEAD`` macro. + +These macros are used in the definition of :ctype:`PyObject` and +:ctype:`PyVarObject`: + + +.. cmacro:: PyObject_HEAD + + This is a macro which expands to the declarations of the fields of the + :ctype:`PyObject` type; it is used when declaring new types which represent + objects without a varying length. The specific fields it expands to depend on + the definition of :cmacro:`Py_TRACE_REFS`. By default, that macro is not + defined, and :cmacro:`PyObject_HEAD` expands to:: + + Py_ssize_t ob_refcnt; + PyTypeObject *ob_type; + + When :cmacro:`Py_TRACE_REFS` is defined, it expands to:: + + PyObject *_ob_next, *_ob_prev; + Py_ssize_t ob_refcnt; + PyTypeObject *ob_type; + + +.. cmacro:: PyObject_VAR_HEAD + + This is a macro which expands to the declarations of the fields of the + :ctype:`PyVarObject` type; it is used when declaring new types which represent + objects with a length that varies from instance to instance. This macro always + expands to:: + + PyObject_HEAD + Py_ssize_t ob_size; + + Note that :cmacro:`PyObject_HEAD` is part of the expansion, and that its own + expansion varies depending on the definition of :cmacro:`Py_TRACE_REFS`. + +PyObject_HEAD_INIT + + +.. ctype:: PyCFunction + + Type of the functions used to implement most Python callables in C. Functions of + this type take two :ctype:`PyObject\*` parameters and return one such value. If + the return value is *NULL*, an exception shall have been set. If not *NULL*, + the return value is interpreted as the return value of the function as exposed + in Python. The function must return a new reference. + + +.. ctype:: PyMethodDef + + Structure used to describe a method of an extension type. This structure has + four fields: + + +------------------+-------------+-------------------------------+ + | Field | C Type | Meaning | + +==================+=============+===============================+ + | :attr:`ml_name` | char \* | name of the method | + +------------------+-------------+-------------------------------+ + | :attr:`ml_meth` | PyCFunction | pointer to the C | + | | | implementation | + +------------------+-------------+-------------------------------+ + | :attr:`ml_flags` | int | flag bits indicating how the | + | | | call should be constructed | + +------------------+-------------+-------------------------------+ + | :attr:`ml_doc` | char \* | points to the contents of the | + | | | docstring | + +------------------+-------------+-------------------------------+ + +The :attr:`ml_meth` is a C function pointer. The functions may be of different +types, but they always return :ctype:`PyObject\*`. If the function is not of +the :ctype:`PyCFunction`, the compiler will require a cast in the method table. +Even though :ctype:`PyCFunction` defines the first parameter as +:ctype:`PyObject\*`, it is common that the method implementation uses a the +specific C type of the *self* object. + +The :attr:`ml_flags` field is a bitfield which can include the following flags. +The individual flags indicate either a calling convention or a binding +convention. Of the calling convention flags, only :const:`METH_VARARGS` and +:const:`METH_KEYWORDS` can be combined (but note that :const:`METH_KEYWORDS` +alone is equivalent to ``METH_VARARGS | METH_KEYWORDS``). Any of the calling +convention flags can be combined with a binding flag. + + +.. data:: METH_VARARGS + + This is the typical calling convention, where the methods have the type + :ctype:`PyCFunction`. The function expects two :ctype:`PyObject\*` values. The + first one is the *self* object for methods; for module functions, it has the + value given to :cfunc:`Py_InitModule4` (or *NULL* if :cfunc:`Py_InitModule` was + used). The second parameter (often called *args*) is a tuple object + representing all arguments. This parameter is typically processed using + :cfunc:`PyArg_ParseTuple` or :cfunc:`PyArg_UnpackTuple`. + + +.. data:: METH_KEYWORDS + + Methods with these flags must be of type :ctype:`PyCFunctionWithKeywords`. The + function expects three parameters: *self*, *args*, and a dictionary of all the + keyword arguments. The flag is typically combined with :const:`METH_VARARGS`, + and the parameters are typically processed using + :cfunc:`PyArg_ParseTupleAndKeywords`. + + +.. data:: METH_NOARGS + + Methods without parameters don't need to check whether arguments are given if + they are listed with the :const:`METH_NOARGS` flag. They need to be of type + :ctype:`PyCFunction`. When used with object methods, the first parameter is + typically named ``self`` and will hold a reference to the object instance. In + all cases the second parameter will be *NULL*. + + +.. data:: METH_O + + Methods with a single object argument can be listed with the :const:`METH_O` + flag, instead of invoking :cfunc:`PyArg_ParseTuple` with a ``"O"`` argument. + They have the type :ctype:`PyCFunction`, with the *self* parameter, and a + :ctype:`PyObject\*` parameter representing the single argument. + + +.. data:: METH_OLDARGS + + This calling convention is deprecated. The method must be of type + :ctype:`PyCFunction`. The second argument is *NULL* if no arguments are given, + a single object if exactly one argument is given, and a tuple of objects if more + than one argument is given. There is no way for a function using this + convention to distinguish between a call with multiple arguments and a call with + a tuple as the only argument. + +These two constants are not used to indicate the calling convention but the +binding when use with methods of classes. These may not be used for functions +defined for modules. At most one of these flags may be set for any given +method. + + +.. data:: METH_CLASS + + .. index:: builtin: classmethod + + The method will be passed the type object as the first parameter rather than an + instance of the type. This is used to create *class methods*, similar to what + is created when using the :func:`classmethod` built-in function. + + .. versionadded:: 2.3 + + +.. data:: METH_STATIC + + .. index:: builtin: staticmethod + + The method will be passed *NULL* as the first parameter rather than an instance + of the type. This is used to create *static methods*, similar to what is + created when using the :func:`staticmethod` built-in function. + + .. versionadded:: 2.3 + +One other constant controls whether a method is loaded in place of another +definition with the same method name. + + +.. data:: METH_COEXIST + + The method will be loaded in place of existing definitions. Without + *METH_COEXIST*, the default is to skip repeated definitions. Since slot + wrappers are loaded before the method table, the existence of a *sq_contains* + slot, for example, would generate a wrapped method named :meth:`__contains__` + and preclude the loading of a corresponding PyCFunction with the same name. + With the flag defined, the PyCFunction will be loaded in place of the wrapper + object and will co-exist with the slot. This is helpful because calls to + PyCFunctions are optimized more than wrapper object calls. + + .. versionadded:: 2.4 + + +.. cfunction:: PyObject* Py_FindMethod(PyMethodDef table[], PyObject *ob, char *name) + + Return a bound method object for an extension type implemented in C. This can + be useful in the implementation of a :attr:`tp_getattro` or :attr:`tp_getattr` + handler that does not use the :cfunc:`PyObject_GenericGetAttr` function. + + +.. _type-structs: + +Type Objects +============ + +Perhaps one of the most important structures of the Python object system is the +structure that defines a new type: the :ctype:`PyTypeObject` structure. Type +objects can be handled using any of the :cfunc:`PyObject_\*` or +:cfunc:`PyType_\*` functions, but do not offer much that's interesting to most +Python applications. These objects are fundamental to how objects behave, so +they are very important to the interpreter itself and to any extension module +that implements new types. + +Type objects are fairly large compared to most of the standard types. The reason +for the size is that each type object stores a large number of values, mostly C +function pointers, each of which implements a small part of the type's +functionality. The fields of the type object are examined in detail in this +section. The fields will be described in the order in which they occur in the +structure. + +Typedefs: unaryfunc, binaryfunc, ternaryfunc, inquiry, coercion, intargfunc, +intintargfunc, intobjargproc, intintobjargproc, objobjargproc, destructor, +freefunc, printfunc, getattrfunc, getattrofunc, setattrfunc, setattrofunc, +cmpfunc, reprfunc, hashfunc + +The structure definition for :ctype:`PyTypeObject` can be found in +:file:`Include/object.h`. For convenience of reference, this repeats the +definition found there: + +.. literalinclude:: ../includes/typestruct.h + + +The type object structure extends the :ctype:`PyVarObject` structure. The +:attr:`ob_size` field is used for dynamic types (created by :func:`type_new`, +usually called from a class statement). Note that :cdata:`PyType_Type` (the +metatype) initializes :attr:`tp_itemsize`, which means that its instances (i.e. +type objects) *must* have the :attr:`ob_size` field. + + +.. cmember:: PyObject* PyObject._ob_next + PyObject* PyObject._ob_prev + + These fields are only present when the macro ``Py_TRACE_REFS`` is defined. + Their initialization to *NULL* is taken care of by the ``PyObject_HEAD_INIT`` + macro. For statically allocated objects, these fields always remain *NULL*. + For dynamically allocated objects, these two fields are used to link the object + into a doubly-linked list of *all* live objects on the heap. This could be used + for various debugging purposes; currently the only use is to print the objects + that are still alive at the end of a run when the environment variable + :envvar:`PYTHONDUMPREFS` is set. + + These fields are not inherited by subtypes. + + +.. cmember:: Py_ssize_t PyObject.ob_refcnt + + This is the type object's reference count, initialized to ``1`` by the + ``PyObject_HEAD_INIT`` macro. Note that for statically allocated type objects, + the type's instances (objects whose :attr:`ob_type` points back to the type) do + *not* count as references. But for dynamically allocated type objects, the + instances *do* count as references. + + This field is not inherited by subtypes. + + +.. cmember:: PyTypeObject* PyObject.ob_type + + This is the type's type, in other words its metatype. It is initialized by the + argument to the ``PyObject_HEAD_INIT`` macro, and its value should normally be + ``&PyType_Type``. However, for dynamically loadable extension modules that must + be usable on Windows (at least), the compiler complains that this is not a valid + initializer. Therefore, the convention is to pass *NULL* to the + ``PyObject_HEAD_INIT`` macro and to initialize this field explicitly at the + start of the module's initialization function, before doing anything else. This + is typically done like this:: + + Foo_Type.ob_type = &PyType_Type; + + This should be done before any instances of the type are created. + :cfunc:`PyType_Ready` checks if :attr:`ob_type` is *NULL*, and if so, + initializes it: in Python 2.2, it is set to ``&PyType_Type``; in Python 2.2.1 + and later it is initialized to the :attr:`ob_type` field of the base class. + :cfunc:`PyType_Ready` will not change this field if it is non-zero. + + In Python 2.2, this field is not inherited by subtypes. In 2.2.1, and in 2.3 + and beyond, it is inherited by subtypes. + + +.. cmember:: Py_ssize_t PyVarObject.ob_size + + For statically allocated type objects, this should be initialized to zero. For + dynamically allocated type objects, this field has a special internal meaning. + + This field is not inherited by subtypes. + + +.. cmember:: char* PyTypeObject.tp_name + + Pointer to a NUL-terminated string containing the name of the type. For types + that are accessible as module globals, the string should be the full module + name, followed by a dot, followed by the type name; for built-in types, it + should be just the type name. If the module is a submodule of a package, the + full package name is part of the full module name. For example, a type named + :class:`T` defined in module :mod:`M` in subpackage :mod:`Q` in package :mod:`P` + should have the :attr:`tp_name` initializer ``"P.Q.M.T"``. + + For dynamically allocated type objects, this should just be the type name, and + the module name explicitly stored in the type dict as the value for key + ``'__module__'``. + + For statically allocated type objects, the tp_name field should contain a dot. + Everything before the last dot is made accessible as the :attr:`__module__` + attribute, and everything after the last dot is made accessible as the + :attr:`__name__` attribute. + + If no dot is present, the entire :attr:`tp_name` field is made accessible as the + :attr:`__name__` attribute, and the :attr:`__module__` attribute is undefined + (unless explicitly set in the dictionary, as explained above). This means your + type will be impossible to pickle. + + This field is not inherited by subtypes. + + +.. cmember:: Py_ssize_t PyTypeObject.tp_basicsize + Py_ssize_t PyTypeObject.tp_itemsize + + These fields allow calculating the size in bytes of instances of the type. + + There are two kinds of types: types with fixed-length instances have a zero + :attr:`tp_itemsize` field, types with variable-length instances have a non-zero + :attr:`tp_itemsize` field. For a type with fixed-length instances, all + instances have the same size, given in :attr:`tp_basicsize`. + + For a type with variable-length instances, the instances must have an + :attr:`ob_size` field, and the instance size is :attr:`tp_basicsize` plus N + times :attr:`tp_itemsize`, where N is the "length" of the object. The value of + N is typically stored in the instance's :attr:`ob_size` field. There are + exceptions: for example, long ints use a negative :attr:`ob_size` to indicate a + negative number, and N is ``abs(ob_size)`` there. Also, the presence of an + :attr:`ob_size` field in the instance layout doesn't mean that the instance + structure is variable-length (for example, the structure for the list type has + fixed-length instances, yet those instances have a meaningful :attr:`ob_size` + field). + + The basic size includes the fields in the instance declared by the macro + :cmacro:`PyObject_HEAD` or :cmacro:`PyObject_VAR_HEAD` (whichever is used to + declare the instance struct) and this in turn includes the :attr:`_ob_prev` and + :attr:`_ob_next` fields if they are present. This means that the only correct + way to get an initializer for the :attr:`tp_basicsize` is to use the + :keyword:`sizeof` operator on the struct used to declare the instance layout. + The basic size does not include the GC header size (this is new in Python 2.2; + in 2.1 and 2.0, the GC header size was included in :attr:`tp_basicsize`). + + These fields are inherited separately by subtypes. If the base type has a + non-zero :attr:`tp_itemsize`, it is generally not safe to set + :attr:`tp_itemsize` to a different non-zero value in a subtype (though this + depends on the implementation of the base type). + + A note about alignment: if the variable items require a particular alignment, + this should be taken care of by the value of :attr:`tp_basicsize`. Example: + suppose a type implements an array of ``double``. :attr:`tp_itemsize` is + ``sizeof(double)``. It is the programmer's responsibility that + :attr:`tp_basicsize` is a multiple of ``sizeof(double)`` (assuming this is the + alignment requirement for ``double``). + + +.. cmember:: destructor PyTypeObject.tp_dealloc + + A pointer to the instance destructor function. This function must be defined + unless the type guarantees that its instances will never be deallocated (as is + the case for the singletons ``None`` and ``Ellipsis``). + + The destructor function is called by the :cfunc:`Py_DECREF` and + :cfunc:`Py_XDECREF` macros when the new reference count is zero. At this point, + the instance is still in existence, but there are no references to it. The + destructor function should free all references which the instance owns, free all + memory buffers owned by the instance (using the freeing function corresponding + to the allocation function used to allocate the buffer), and finally (as its + last action) call the type's :attr:`tp_free` function. If the type is not + subtypable (doesn't have the :const:`Py_TPFLAGS_BASETYPE` flag bit set), it is + permissible to call the object deallocator directly instead of via + :attr:`tp_free`. The object deallocator should be the one used to allocate the + instance; this is normally :cfunc:`PyObject_Del` if the instance was allocated + using :cfunc:`PyObject_New` or :cfunc:`PyObject_VarNew`, or + :cfunc:`PyObject_GC_Del` if the instance was allocated using + :cfunc:`PyObject_GC_New` or :cfunc:`PyObject_GC_VarNew`. + + This field is inherited by subtypes. + + +.. cmember:: printfunc PyTypeObject.tp_print + + An optional pointer to the instance print function. + + The print function is only called when the instance is printed to a *real* file; + when it is printed to a pseudo-file (like a :class:`StringIO` instance), the + instance's :attr:`tp_repr` or :attr:`tp_str` function is called to convert it to + a string. These are also called when the type's :attr:`tp_print` field is + *NULL*. A type should never implement :attr:`tp_print` in a way that produces + different output than :attr:`tp_repr` or :attr:`tp_str` would. + + The print function is called with the same signature as :cfunc:`PyObject_Print`: + ``int tp_print(PyObject *self, FILE *file, int flags)``. The *self* argument is + the instance to be printed. The *file* argument is the stdio file to which it + is to be printed. The *flags* argument is composed of flag bits. The only flag + bit currently defined is :const:`Py_PRINT_RAW`. When the :const:`Py_PRINT_RAW` + flag bit is set, the instance should be printed the same way as :attr:`tp_str` + would format it; when the :const:`Py_PRINT_RAW` flag bit is clear, the instance + should be printed the same was as :attr:`tp_repr` would format it. It should + return ``-1`` and set an exception condition when an error occurred during the + comparison. + + It is possible that the :attr:`tp_print` field will be deprecated. In any case, + it is recommended not to define :attr:`tp_print`, but instead to rely on + :attr:`tp_repr` and :attr:`tp_str` for printing. + + This field is inherited by subtypes. + + +.. cmember:: getattrfunc PyTypeObject.tp_getattr + + An optional pointer to the get-attribute-string function. + + This field is deprecated. When it is defined, it should point to a function + that acts the same as the :attr:`tp_getattro` function, but taking a C string + instead of a Python string object to give the attribute name. The signature is + the same as for :cfunc:`PyObject_GetAttrString`. + + This field is inherited by subtypes together with :attr:`tp_getattro`: a subtype + inherits both :attr:`tp_getattr` and :attr:`tp_getattro` from its base type when + the subtype's :attr:`tp_getattr` and :attr:`tp_getattro` are both *NULL*. + + +.. cmember:: setattrfunc PyTypeObject.tp_setattr + + An optional pointer to the set-attribute-string function. + + This field is deprecated. When it is defined, it should point to a function + that acts the same as the :attr:`tp_setattro` function, but taking a C string + instead of a Python string object to give the attribute name. The signature is + the same as for :cfunc:`PyObject_SetAttrString`. + + This field is inherited by subtypes together with :attr:`tp_setattro`: a subtype + inherits both :attr:`tp_setattr` and :attr:`tp_setattro` from its base type when + the subtype's :attr:`tp_setattr` and :attr:`tp_setattro` are both *NULL*. + + +.. cmember:: cmpfunc PyTypeObject.tp_compare + + An optional pointer to the three-way comparison function. + + The signature is the same as for :cfunc:`PyObject_Compare`. The function should + return ``1`` if *self* greater than *other*, ``0`` if *self* is equal to + *other*, and ``-1`` if *self* less than *other*. It should return ``-1`` and + set an exception condition when an error occurred during the comparison. + + This field is inherited by subtypes together with :attr:`tp_richcompare` and + :attr:`tp_hash`: a subtypes inherits all three of :attr:`tp_compare`, + :attr:`tp_richcompare`, and :attr:`tp_hash` when the subtype's + :attr:`tp_compare`, :attr:`tp_richcompare`, and :attr:`tp_hash` are all *NULL*. + + +.. cmember:: reprfunc PyTypeObject.tp_repr + + .. index:: builtin: repr + + An optional pointer to a function that implements the built-in function + :func:`repr`. + + The signature is the same as for :cfunc:`PyObject_Repr`; it must return a string + or a Unicode object. Ideally, this function should return a string that, when + passed to :func:`eval`, given a suitable environment, returns an object with the + same value. If this is not feasible, it should return a string starting with + ``'<'`` and ending with ``'>'`` from which both the type and the value of the + object can be deduced. + + When this field is not set, a string of the form ``<%s object at %p>`` is + returned, where ``%s`` is replaced by the type name, and ``%p`` by the object's + memory address. + + This field is inherited by subtypes. + +.. cmember:: PyNumberMethods *tp_as_number; + + XXX + +.. cmember:: PySequenceMethods *tp_as_sequence; + + XXX + +.. cmember:: PyMappingMethods *tp_as_mapping; + + XXX + + +.. cmember:: hashfunc PyTypeObject.tp_hash + + .. index:: builtin: hash + + An optional pointer to a function that implements the built-in function + :func:`hash`. + + The signature is the same as for :cfunc:`PyObject_Hash`; it must return a C + long. The value ``-1`` should not be returned as a normal return value; when an + error occurs during the computation of the hash value, the function should set + an exception and return ``-1``. + + When this field is not set, two possibilities exist: if the :attr:`tp_compare` + and :attr:`tp_richcompare` fields are both *NULL*, a default hash value based on + the object's address is returned; otherwise, a :exc:`TypeError` is raised. + + This field is inherited by subtypes together with :attr:`tp_richcompare` and + :attr:`tp_compare`: a subtypes inherits all three of :attr:`tp_compare`, + :attr:`tp_richcompare`, and :attr:`tp_hash`, when the subtype's + :attr:`tp_compare`, :attr:`tp_richcompare` and :attr:`tp_hash` are all *NULL*. + + +.. cmember:: ternaryfunc PyTypeObject.tp_call + + An optional pointer to a function that implements calling the object. This + should be *NULL* if the object is not callable. The signature is the same as + for :cfunc:`PyObject_Call`. + + This field is inherited by subtypes. + + +.. cmember:: reprfunc PyTypeObject.tp_str + + An optional pointer to a function that implements the built-in operation + :func:`str`. (Note that :class:`str` is a type now, and :func:`str` calls the + constructor for that type. This constructor calls :cfunc:`PyObject_Str` to do + the actual work, and :cfunc:`PyObject_Str` will call this handler.) + + The signature is the same as for :cfunc:`PyObject_Str`; it must return a string + or a Unicode object. This function should return a "friendly" string + representation of the object, as this is the representation that will be used by + the print statement. + + When this field is not set, :cfunc:`PyObject_Repr` is called to return a string + representation. + + This field is inherited by subtypes. + + +.. cmember:: getattrofunc PyTypeObject.tp_getattro + + An optional pointer to the get-attribute function. + + The signature is the same as for :cfunc:`PyObject_GetAttr`. It is usually + convenient to set this field to :cfunc:`PyObject_GenericGetAttr`, which + implements the normal way of looking for object attributes. + + This field is inherited by subtypes together with :attr:`tp_getattr`: a subtype + inherits both :attr:`tp_getattr` and :attr:`tp_getattro` from its base type when + the subtype's :attr:`tp_getattr` and :attr:`tp_getattro` are both *NULL*. + + +.. cmember:: setattrofunc PyTypeObject.tp_setattro + + An optional pointer to the set-attribute function. + + The signature is the same as for :cfunc:`PyObject_SetAttr`. It is usually + convenient to set this field to :cfunc:`PyObject_GenericSetAttr`, which + implements the normal way of setting object attributes. + + This field is inherited by subtypes together with :attr:`tp_setattr`: a subtype + inherits both :attr:`tp_setattr` and :attr:`tp_setattro` from its base type when + the subtype's :attr:`tp_setattr` and :attr:`tp_setattro` are both *NULL*. + + +.. cmember:: PyBufferProcs* PyTypeObject.tp_as_buffer + + Pointer to an additional structure that contains fields relevant only to objects + which implement the buffer interface. These fields are documented in + :ref:`buffer-structs`. + + The :attr:`tp_as_buffer` field is not inherited, but the contained fields are + inherited individually. + + +.. cmember:: long PyTypeObject.tp_flags + + This field is a bit mask of various flags. Some flags indicate variant + semantics for certain situations; others are used to indicate that certain + fields in the type object (or in the extension structures referenced via + :attr:`tp_as_number`, :attr:`tp_as_sequence`, :attr:`tp_as_mapping`, and + :attr:`tp_as_buffer`) that were historically not always present are valid; if + such a flag bit is clear, the type fields it guards must not be accessed and + must be considered to have a zero or *NULL* value instead. + + Inheritance of this field is complicated. Most flag bits are inherited + individually, i.e. if the base type has a flag bit set, the subtype inherits + this flag bit. The flag bits that pertain to extension structures are strictly + inherited if the extension structure is inherited, i.e. the base type's value of + the flag bit is copied into the subtype together with a pointer to the extension + structure. The :const:`Py_TPFLAGS_HAVE_GC` flag bit is inherited together with + the :attr:`tp_traverse` and :attr:`tp_clear` fields, i.e. if the + :const:`Py_TPFLAGS_HAVE_GC` flag bit is clear in the subtype and the + :attr:`tp_traverse` and :attr:`tp_clear` fields in the subtype exist (as + indicated by the :const:`Py_TPFLAGS_HAVE_RICHCOMPARE` flag bit) and have *NULL* + values. + + The following bit masks are currently defined; these can be or-ed together using + the ``|`` operator to form the value of the :attr:`tp_flags` field. The macro + :cfunc:`PyType_HasFeature` takes a type and a flags value, *tp* and *f*, and + checks whether ``tp->tp_flags & f`` is non-zero. + + + .. data:: Py_TPFLAGS_HAVE_GETCHARBUFFER + + If this bit is set, the :ctype:`PyBufferProcs` struct referenced by + :attr:`tp_as_buffer` has the :attr:`bf_getcharbuffer` field. + + + .. data:: Py_TPFLAGS_HAVE_SEQUENCE_IN + + If this bit is set, the :ctype:`PySequenceMethods` struct referenced by + :attr:`tp_as_sequence` has the :attr:`sq_contains` field. + + + .. data:: Py_TPFLAGS_GC + + This bit is obsolete. The bit it used to name is no longer in use. The symbol + is now defined as zero. + + + .. data:: Py_TPFLAGS_HAVE_INPLACEOPS + + If this bit is set, the :ctype:`PySequenceMethods` struct referenced by + :attr:`tp_as_sequence` and the :ctype:`PyNumberMethods` structure referenced by + :attr:`tp_as_number` contain the fields for in-place operators. In particular, + this means that the :ctype:`PyNumberMethods` structure has the fields + :attr:`nb_inplace_add`, :attr:`nb_inplace_subtract`, + :attr:`nb_inplace_multiply`, :attr:`nb_inplace_divide`, + :attr:`nb_inplace_remainder`, :attr:`nb_inplace_power`, + :attr:`nb_inplace_lshift`, :attr:`nb_inplace_rshift`, :attr:`nb_inplace_and`, + :attr:`nb_inplace_xor`, and :attr:`nb_inplace_or`; and the + :ctype:`PySequenceMethods` struct has the fields :attr:`sq_inplace_concat` and + :attr:`sq_inplace_repeat`. + + + .. data:: Py_TPFLAGS_CHECKTYPES + + If this bit is set, the binary and ternary operations in the + :ctype:`PyNumberMethods` structure referenced by :attr:`tp_as_number` accept + arguments of arbitrary object types, and do their own type conversions if + needed. If this bit is clear, those operations require that all arguments have + the current type as their type, and the caller is supposed to perform a coercion + operation first. This applies to :attr:`nb_add`, :attr:`nb_subtract`, + :attr:`nb_multiply`, :attr:`nb_divide`, :attr:`nb_remainder`, :attr:`nb_divmod`, + :attr:`nb_power`, :attr:`nb_lshift`, :attr:`nb_rshift`, :attr:`nb_and`, + :attr:`nb_xor`, and :attr:`nb_or`. + + + .. data:: Py_TPFLAGS_HAVE_RICHCOMPARE + + If this bit is set, the type object has the :attr:`tp_richcompare` field, as + well as the :attr:`tp_traverse` and the :attr:`tp_clear` fields. + + + .. data:: Py_TPFLAGS_HAVE_WEAKREFS + + If this bit is set, the :attr:`tp_weaklistoffset` field is defined. Instances + of a type are weakly referenceable if the type's :attr:`tp_weaklistoffset` field + has a value greater than zero. + + + .. data:: Py_TPFLAGS_HAVE_ITER + + If this bit is set, the type object has the :attr:`tp_iter` and + :attr:`tp_iternext` fields. + + + .. data:: Py_TPFLAGS_HAVE_CLASS + + If this bit is set, the type object has several new fields defined starting in + Python 2.2: :attr:`tp_methods`, :attr:`tp_members`, :attr:`tp_getset`, + :attr:`tp_base`, :attr:`tp_dict`, :attr:`tp_descr_get`, :attr:`tp_descr_set`, + :attr:`tp_dictoffset`, :attr:`tp_init`, :attr:`tp_alloc`, :attr:`tp_new`, + :attr:`tp_free`, :attr:`tp_is_gc`, :attr:`tp_bases`, :attr:`tp_mro`, + :attr:`tp_cache`, :attr:`tp_subclasses`, and :attr:`tp_weaklist`. + + + .. data:: Py_TPFLAGS_HEAPTYPE + + This bit is set when the type object itself is allocated on the heap. In this + case, the :attr:`ob_type` field of its instances is considered a reference to + the type, and the type object is INCREF'ed when a new instance is created, and + DECREF'ed when an instance is destroyed (this does not apply to instances of + subtypes; only the type referenced by the instance's ob_type gets INCREF'ed or + DECREF'ed). + + + .. data:: Py_TPFLAGS_BASETYPE + + This bit is set when the type can be used as the base type of another type. If + this bit is clear, the type cannot be subtyped (similar to a "final" class in + Java). + + + .. data:: Py_TPFLAGS_READY + + This bit is set when the type object has been fully initialized by + :cfunc:`PyType_Ready`. + + + .. data:: Py_TPFLAGS_READYING + + This bit is set while :cfunc:`PyType_Ready` is in the process of initializing + the type object. + + + .. data:: Py_TPFLAGS_HAVE_GC + + This bit is set when the object supports garbage collection. If this bit + is set, instances must be created using :cfunc:`PyObject_GC_New` and + destroyed using :cfunc:`PyObject_GC_Del`. More information in section + :ref:`supporting-cycle-detection`. This bit also implies that the + GC-related fields :attr:`tp_traverse` and :attr:`tp_clear` are present in + the type object; but those fields also exist when + :const:`Py_TPFLAGS_HAVE_GC` is clear but + :const:`Py_TPFLAGS_HAVE_RICHCOMPARE` is set. + + + .. data:: Py_TPFLAGS_DEFAULT + + This is a bitmask of all the bits that pertain to the existence of certain + fields in the type object and its extension structures. Currently, it includes + the following bits: :const:`Py_TPFLAGS_HAVE_GETCHARBUFFER`, + :const:`Py_TPFLAGS_HAVE_SEQUENCE_IN`, :const:`Py_TPFLAGS_HAVE_INPLACEOPS`, + :const:`Py_TPFLAGS_HAVE_RICHCOMPARE`, :const:`Py_TPFLAGS_HAVE_WEAKREFS`, + :const:`Py_TPFLAGS_HAVE_ITER`, and :const:`Py_TPFLAGS_HAVE_CLASS`. + + +.. cmember:: char* PyTypeObject.tp_doc + + An optional pointer to a NUL-terminated C string giving the docstring for this + type object. This is exposed as the :attr:`__doc__` attribute on the type and + instances of the type. + + This field is *not* inherited by subtypes. + +The following three fields only exist if the +:const:`Py_TPFLAGS_HAVE_RICHCOMPARE` flag bit is set. + + +.. cmember:: traverseproc PyTypeObject.tp_traverse + + An optional pointer to a traversal function for the garbage collector. This is + only used if the :const:`Py_TPFLAGS_HAVE_GC` flag bit is set. More information + about Python's garbage collection scheme can be found in section + :ref:`supporting-cycle-detection`. + + The :attr:`tp_traverse` pointer is used by the garbage collector to detect + reference cycles. A typical implementation of a :attr:`tp_traverse` function + simply calls :cfunc:`Py_VISIT` on each of the instance's members that are Python + objects. For exampe, this is function :cfunc:`local_traverse` from the + :mod:`thread` extension module:: + + static int + local_traverse(localobject *self, visitproc visit, void *arg) + { + Py_VISIT(self->args); + Py_VISIT(self->kw); + Py_VISIT(self->dict); + return 0; + } + + Note that :cfunc:`Py_VISIT` is called only on those members that can participate + in reference cycles. Although there is also a ``self->key`` member, it can only + be *NULL* or a Python string and therefore cannot be part of a reference cycle. + + On the other hand, even if you know a member can never be part of a cycle, as a + debugging aid you may want to visit it anyway just so the :mod:`gc` module's + :func:`get_referents` function will include it. + + Note that :cfunc:`Py_VISIT` requires the *visit* and *arg* parameters to + :cfunc:`local_traverse` to have these specific names; don't name them just + anything. + + This field is inherited by subtypes together with :attr:`tp_clear` and the + :const:`Py_TPFLAGS_HAVE_GC` flag bit: the flag bit, :attr:`tp_traverse`, and + :attr:`tp_clear` are all inherited from the base type if they are all zero in + the subtype *and* the subtype has the :const:`Py_TPFLAGS_HAVE_RICHCOMPARE` flag + bit set. + + +.. cmember:: inquiry PyTypeObject.tp_clear + + An optional pointer to a clear function for the garbage collector. This is only + used if the :const:`Py_TPFLAGS_HAVE_GC` flag bit is set. + + The :attr:`tp_clear` member function is used to break reference cycles in cyclic + garbage detected by the garbage collector. Taken together, all :attr:`tp_clear` + functions in the system must combine to break all reference cycles. This is + subtle, and if in any doubt supply a :attr:`tp_clear` function. For example, + the tuple type does not implement a :attr:`tp_clear` function, because it's + possible to prove that no reference cycle can be composed entirely of tuples. + Therefore the :attr:`tp_clear` functions of other types must be sufficient to + break any cycle containing a tuple. This isn't immediately obvious, and there's + rarely a good reason to avoid implementing :attr:`tp_clear`. + + Implementations of :attr:`tp_clear` should drop the instance's references to + those of its members that may be Python objects, and set its pointers to those + members to *NULL*, as in the following example:: + + static int + local_clear(localobject *self) + { + Py_CLEAR(self->key); + Py_CLEAR(self->args); + Py_CLEAR(self->kw); + Py_CLEAR(self->dict); + return 0; + } + + The :cfunc:`Py_CLEAR` macro should be used, because clearing references is + delicate: the reference to the contained object must not be decremented until + after the pointer to the contained object is set to *NULL*. This is because + decrementing the reference count may cause the contained object to become trash, + triggering a chain of reclamation activity that may include invoking arbitrary + Python code (due to finalizers, or weakref callbacks, associated with the + contained object). If it's possible for such code to reference *self* again, + it's important that the pointer to the contained object be *NULL* at that time, + so that *self* knows the contained object can no longer be used. The + :cfunc:`Py_CLEAR` macro performs the operations in a safe order. + + Because the goal of :attr:`tp_clear` functions is to break reference cycles, + it's not necessary to clear contained objects like Python strings or Python + integers, which can't participate in reference cycles. On the other hand, it may + be convenient to clear all contained Python objects, and write the type's + :attr:`tp_dealloc` function to invoke :attr:`tp_clear`. + + More information about Python's garbage collection scheme can be found in + section :ref:`supporting-cycle-detection`. + + This field is inherited by subtypes together with :attr:`tp_traverse` and the + :const:`Py_TPFLAGS_HAVE_GC` flag bit: the flag bit, :attr:`tp_traverse`, and + :attr:`tp_clear` are all inherited from the base type if they are all zero in + the subtype *and* the subtype has the :const:`Py_TPFLAGS_HAVE_RICHCOMPARE` flag + bit set. + + +.. cmember:: richcmpfunc PyTypeObject.tp_richcompare + + An optional pointer to the rich comparison function. + + The signature is the same as for :cfunc:`PyObject_RichCompare`. The function + should return the result of the comparison (usually ``Py_True`` or + ``Py_False``). If the comparison is undefined, it must return + ``Py_NotImplemented``, if another error occurred it must return ``NULL`` and set + an exception condition. + + This field is inherited by subtypes together with :attr:`tp_compare` and + :attr:`tp_hash`: a subtype inherits all three of :attr:`tp_compare`, + :attr:`tp_richcompare`, and :attr:`tp_hash`, when the subtype's + :attr:`tp_compare`, :attr:`tp_richcompare`, and :attr:`tp_hash` are all *NULL*. + + The following constants are defined to be used as the third argument for + :attr:`tp_richcompare` and for :cfunc:`PyObject_RichCompare`: + + +----------------+------------+ + | Constant | Comparison | + +================+============+ + | :const:`Py_LT` | ``<`` | + +----------------+------------+ + | :const:`Py_LE` | ``<=`` | + +----------------+------------+ + | :const:`Py_EQ` | ``==`` | + +----------------+------------+ + | :const:`Py_NE` | ``!=`` | + +----------------+------------+ + | :const:`Py_GT` | ``>`` | + +----------------+------------+ + | :const:`Py_GE` | ``>=`` | + +----------------+------------+ + +The next field only exists if the :const:`Py_TPFLAGS_HAVE_WEAKREFS` flag bit is +set. + + +.. cmember:: long PyTypeObject.tp_weaklistoffset + + If the instances of this type are weakly referenceable, this field is greater + than zero and contains the offset in the instance structure of the weak + reference list head (ignoring the GC header, if present); this offset is used by + :cfunc:`PyObject_ClearWeakRefs` and the :cfunc:`PyWeakref_\*` functions. The + instance structure needs to include a field of type :ctype:`PyObject\*` which is + initialized to *NULL*. + + Do not confuse this field with :attr:`tp_weaklist`; that is the list head for + weak references to the type object itself. + + This field is inherited by subtypes, but see the rules listed below. A subtype + may override this offset; this means that the subtype uses a different weak + reference list head than the base type. Since the list head is always found via + :attr:`tp_weaklistoffset`, this should not be a problem. + + When a type defined by a class statement has no :attr:`__slots__` declaration, + and none of its base types are weakly referenceable, the type is made weakly + referenceable by adding a weak reference list head slot to the instance layout + and setting the :attr:`tp_weaklistoffset` of that slot's offset. + + When a type's :attr:`__slots__` declaration contains a slot named + :attr:`__weakref__`, that slot becomes the weak reference list head for + instances of the type, and the slot's offset is stored in the type's + :attr:`tp_weaklistoffset`. + + When a type's :attr:`__slots__` declaration does not contain a slot named + :attr:`__weakref__`, the type inherits its :attr:`tp_weaklistoffset` from its + base type. + +The next two fields only exist if the :const:`Py_TPFLAGS_HAVE_CLASS` flag bit is +set. + + +.. cmember:: getiterfunc PyTypeObject.tp_iter + + An optional pointer to a function that returns an iterator for the object. Its + presence normally signals that the instances of this type are iterable (although + sequences may be iterable without this function, and classic instances always + have this function, even if they don't define an :meth:`__iter__` method). + + This function has the same signature as :cfunc:`PyObject_GetIter`. + + This field is inherited by subtypes. + + +.. cmember:: iternextfunc PyTypeObject.tp_iternext + + An optional pointer to a function that returns the next item in an iterator, or + raises :exc:`StopIteration` when the iterator is exhausted. Its presence + normally signals that the instances of this type are iterators (although classic + instances always have this function, even if they don't define a + :meth:`__next__` method). + + Iterator types should also define the :attr:`tp_iter` function, and that + function should return the iterator instance itself (not a new iterator + instance). + + This function has the same signature as :cfunc:`PyIter_Next`. + + This field is inherited by subtypes. + +The next fields, up to and including :attr:`tp_weaklist`, only exist if the +:const:`Py_TPFLAGS_HAVE_CLASS` flag bit is set. + + +.. cmember:: struct PyMethodDef* PyTypeObject.tp_methods + + An optional pointer to a static *NULL*-terminated array of :ctype:`PyMethodDef` + structures, declaring regular methods of this type. + + For each entry in the array, an entry is added to the type's dictionary (see + :attr:`tp_dict` below) containing a method descriptor. + + This field is not inherited by subtypes (methods are inherited through a + different mechanism). + + +.. cmember:: struct PyMemberDef* PyTypeObject.tp_members + + An optional pointer to a static *NULL*-terminated array of :ctype:`PyMemberDef` + structures, declaring regular data members (fields or slots) of instances of + this type. + + For each entry in the array, an entry is added to the type's dictionary (see + :attr:`tp_dict` below) containing a member descriptor. + + This field is not inherited by subtypes (members are inherited through a + different mechanism). + + +.. cmember:: struct PyGetSetDef* PyTypeObject.tp_getset + + An optional pointer to a static *NULL*-terminated array of :ctype:`PyGetSetDef` + structures, declaring computed attributes of instances of this type. + + For each entry in the array, an entry is added to the type's dictionary (see + :attr:`tp_dict` below) containing a getset descriptor. + + This field is not inherited by subtypes (computed attributes are inherited + through a different mechanism). + + Docs for PyGetSetDef (XXX belong elsewhere):: + + typedef PyObject *(*getter)(PyObject *, void *); + typedef int (*setter)(PyObject *, PyObject *, void *); + + typedef struct PyGetSetDef { + char *name; /* attribute name */ + getter get; /* C function to get the attribute */ + setter set; /* C function to set the attribute */ + char *doc; /* optional doc string */ + void *closure; /* optional additional data for getter and setter */ + } PyGetSetDef; + + +.. cmember:: PyTypeObject* PyTypeObject.tp_base + + An optional pointer to a base type from which type properties are inherited. At + this level, only single inheritance is supported; multiple inheritance require + dynamically creating a type object by calling the metatype. + + This field is not inherited by subtypes (obviously), but it defaults to + ``&PyBaseObject_Type`` (which to Python programmers is known as the type + :class:`object`). + + +.. cmember:: PyObject* PyTypeObject.tp_dict + + The type's dictionary is stored here by :cfunc:`PyType_Ready`. + + This field should normally be initialized to *NULL* before PyType_Ready is + called; it may also be initialized to a dictionary containing initial attributes + for the type. Once :cfunc:`PyType_Ready` has initialized the type, extra + attributes for the type may be added to this dictionary only if they don't + correspond to overloaded operations (like :meth:`__add__`). + + This field is not inherited by subtypes (though the attributes defined in here + are inherited through a different mechanism). + + +.. cmember:: descrgetfunc PyTypeObject.tp_descr_get + + An optional pointer to a "descriptor get" function. + + The function signature is :: + + PyObject * tp_descr_get(PyObject *self, PyObject *obj, PyObject *type); + + XXX blah, blah. + + This field is inherited by subtypes. + + +.. cmember:: descrsetfunc PyTypeObject.tp_descr_set + + An optional pointer to a "descriptor set" function. + + The function signature is :: + + int tp_descr_set(PyObject *self, PyObject *obj, PyObject *value); + + This field is inherited by subtypes. + + XXX blah, blah. + + +.. cmember:: long PyTypeObject.tp_dictoffset + + If the instances of this type have a dictionary containing instance variables, + this field is non-zero and contains the offset in the instances of the type of + the instance variable dictionary; this offset is used by + :cfunc:`PyObject_GenericGetAttr`. + + Do not confuse this field with :attr:`tp_dict`; that is the dictionary for + attributes of the type object itself. + + If the value of this field is greater than zero, it specifies the offset from + the start of the instance structure. If the value is less than zero, it + specifies the offset from the *end* of the instance structure. A negative + offset is more expensive to use, and should only be used when the instance + structure contains a variable-length part. This is used for example to add an + instance variable dictionary to subtypes of :class:`str` or :class:`tuple`. Note + that the :attr:`tp_basicsize` field should account for the dictionary added to + the end in that case, even though the dictionary is not included in the basic + object layout. On a system with a pointer size of 4 bytes, + :attr:`tp_dictoffset` should be set to ``-4`` to indicate that the dictionary is + at the very end of the structure. + + The real dictionary offset in an instance can be computed from a negative + :attr:`tp_dictoffset` as follows:: + + dictoffset = tp_basicsize + abs(ob_size)*tp_itemsize + tp_dictoffset + if dictoffset is not aligned on sizeof(void*): + round up to sizeof(void*) + + where :attr:`tp_basicsize`, :attr:`tp_itemsize` and :attr:`tp_dictoffset` are + taken from the type object, and :attr:`ob_size` is taken from the instance. The + absolute value is taken because long ints use the sign of :attr:`ob_size` to + store the sign of the number. (There's never a need to do this calculation + yourself; it is done for you by :cfunc:`_PyObject_GetDictPtr`.) + + This field is inherited by subtypes, but see the rules listed below. A subtype + may override this offset; this means that the subtype instances store the + dictionary at a difference offset than the base type. Since the dictionary is + always found via :attr:`tp_dictoffset`, this should not be a problem. + + When a type defined by a class statement has no :attr:`__slots__` declaration, + and none of its base types has an instance variable dictionary, a dictionary + slot is added to the instance layout and the :attr:`tp_dictoffset` is set to + that slot's offset. + + When a type defined by a class statement has a :attr:`__slots__` declaration, + the type inherits its :attr:`tp_dictoffset` from its base type. + + (Adding a slot named :attr:`__dict__` to the :attr:`__slots__` declaration does + not have the expected effect, it just causes confusion. Maybe this should be + added as a feature just like :attr:`__weakref__` though.) + + +.. cmember:: initproc PyTypeObject.tp_init + + An optional pointer to an instance initialization function. + + This function corresponds to the :meth:`__init__` method of classes. Like + :meth:`__init__`, it is possible to create an instance without calling + :meth:`__init__`, and it is possible to reinitialize an instance by calling its + :meth:`__init__` method again. + + The function signature is :: + + int tp_init(PyObject *self, PyObject *args, PyObject *kwds) + + The self argument is the instance to be initialized; the *args* and *kwds* + arguments represent positional and keyword arguments of the call to + :meth:`__init__`. + + The :attr:`tp_init` function, if not *NULL*, is called when an instance is + created normally by calling its type, after the type's :attr:`tp_new` function + has returned an instance of the type. If the :attr:`tp_new` function returns an + instance of some other type that is not a subtype of the original type, no + :attr:`tp_init` function is called; if :attr:`tp_new` returns an instance of a + subtype of the original type, the subtype's :attr:`tp_init` is called. (VERSION + NOTE: described here is what is implemented in Python 2.2.1 and later. In + Python 2.2, the :attr:`tp_init` of the type of the object returned by + :attr:`tp_new` was always called, if not *NULL*.) + + This field is inherited by subtypes. + + +.. cmember:: allocfunc PyTypeObject.tp_alloc + + An optional pointer to an instance allocation function. + + The function signature is :: + + PyObject *tp_alloc(PyTypeObject *self, Py_ssize_t nitems) + + The purpose of this function is to separate memory allocation from memory + initialization. It should return a pointer to a block of memory of adequate + length for the instance, suitably aligned, and initialized to zeros, but with + :attr:`ob_refcnt` set to ``1`` and :attr:`ob_type` set to the type argument. If + the type's :attr:`tp_itemsize` is non-zero, the object's :attr:`ob_size` field + should be initialized to *nitems* and the length of the allocated memory block + should be ``tp_basicsize + nitems*tp_itemsize``, rounded up to a multiple of + ``sizeof(void*)``; otherwise, *nitems* is not used and the length of the block + should be :attr:`tp_basicsize`. + + Do not use this function to do any other instance initialization, not even to + allocate additional memory; that should be done by :attr:`tp_new`. + + This field is inherited by static subtypes, but not by dynamic subtypes + (subtypes created by a class statement); in the latter, this field is always set + to :cfunc:`PyType_GenericAlloc`, to force a standard heap allocation strategy. + That is also the recommended value for statically defined types. + + +.. cmember:: newfunc PyTypeObject.tp_new + + An optional pointer to an instance creation function. + + If this function is *NULL* for a particular type, that type cannot be called to + create new instances; presumably there is some other way to create instances, + like a factory function. + + The function signature is :: + + PyObject *tp_new(PyTypeObject *subtype, PyObject *args, PyObject *kwds) + + The subtype argument is the type of the object being created; the *args* and + *kwds* arguments represent positional and keyword arguments of the call to the + type. Note that subtype doesn't have to equal the type whose :attr:`tp_new` + function is called; it may be a subtype of that type (but not an unrelated + type). + + The :attr:`tp_new` function should call ``subtype->tp_alloc(subtype, nitems)`` + to allocate space for the object, and then do only as much further + initialization as is absolutely necessary. Initialization that can safely be + ignored or repeated should be placed in the :attr:`tp_init` handler. A good + rule of thumb is that for immutable types, all initialization should take place + in :attr:`tp_new`, while for mutable types, most initialization should be + deferred to :attr:`tp_init`. + + This field is inherited by subtypes, except it is not inherited by static types + whose :attr:`tp_base` is *NULL* or ``&PyBaseObject_Type``. The latter exception + is a precaution so that old extension types don't become callable simply by + being linked with Python 2.2. + + +.. cmember:: destructor PyTypeObject.tp_free + + An optional pointer to an instance deallocation function. + + The signature of this function has changed slightly: in Python 2.2 and 2.2.1, + its signature is :ctype:`destructor`:: + + void tp_free(PyObject *) + + In Python 2.3 and beyond, its signature is :ctype:`freefunc`:: + + void tp_free(void *) + + The only initializer that is compatible with both versions is ``_PyObject_Del``, + whose definition has suitably adapted in Python 2.3. + + This field is inherited by static subtypes, but not by dynamic subtypes + (subtypes created by a class statement); in the latter, this field is set to a + deallocator suitable to match :cfunc:`PyType_GenericAlloc` and the value of the + :const:`Py_TPFLAGS_HAVE_GC` flag bit. + + +.. cmember:: inquiry PyTypeObject.tp_is_gc + + An optional pointer to a function called by the garbage collector. + + The garbage collector needs to know whether a particular object is collectible + or not. Normally, it is sufficient to look at the object's type's + :attr:`tp_flags` field, and check the :const:`Py_TPFLAGS_HAVE_GC` flag bit. But + some types have a mixture of statically and dynamically allocated instances, and + the statically allocated instances are not collectible. Such types should + define this function; it should return ``1`` for a collectible instance, and + ``0`` for a non-collectible instance. The signature is :: + + int tp_is_gc(PyObject *self) + + (The only example of this are types themselves. The metatype, + :cdata:`PyType_Type`, defines this function to distinguish between statically + and dynamically allocated types.) + + This field is inherited by subtypes. (VERSION NOTE: in Python 2.2, it was not + inherited. It is inherited in 2.2.1 and later versions.) + + +.. cmember:: PyObject* PyTypeObject.tp_bases + + Tuple of base types. + + This is set for types created by a class statement. It should be *NULL* for + statically defined types. + + This field is not inherited. + + +.. cmember:: PyObject* PyTypeObject.tp_mro + + Tuple containing the expanded set of base types, starting with the type itself + and ending with :class:`object`, in Method Resolution Order. + + This field is not inherited; it is calculated fresh by :cfunc:`PyType_Ready`. + + +.. cmember:: PyObject* PyTypeObject.tp_cache + + Unused. Not inherited. Internal use only. + + +.. cmember:: PyObject* PyTypeObject.tp_subclasses + + List of weak references to subclasses. Not inherited. Internal use only. + + +.. cmember:: PyObject* PyTypeObject.tp_weaklist + + Weak reference list head, for weak references to this type object. Not + inherited. Internal use only. + +The remaining fields are only defined if the feature test macro +:const:`COUNT_ALLOCS` is defined, and are for internal use only. They are +documented here for completeness. None of these fields are inherited by +subtypes. + + +.. cmember:: Py_ssize_t PyTypeObject.tp_allocs + + Number of allocations. + + +.. cmember:: Py_ssize_t PyTypeObject.tp_frees + + Number of frees. + + +.. cmember:: Py_ssize_t PyTypeObject.tp_maxalloc + + Maximum simultaneously allocated objects. + + +.. cmember:: PyTypeObject* PyTypeObject.tp_next + + Pointer to the next type object with a non-zero :attr:`tp_allocs` field. + +Also, note that, in a garbage collected Python, tp_dealloc may be called from +any Python thread, not just the thread which created the object (if the object +becomes part of a refcount cycle, that cycle might be collected by a garbage +collection on any thread). This is not a problem for Python API calls, since +the thread on which tp_dealloc is called will own the Global Interpreter Lock +(GIL). However, if the object being destroyed in turn destroys objects from some +other C or C++ library, care should be taken to ensure that destroying those +objects on the thread which called tp_dealloc will not violate any assumptions +of the library. + + +.. _mapping-structs: + +Mapping Object Structures +========================= + + +.. ctype:: PyMappingMethods + + Structure used to hold pointers to the functions used to implement the mapping + protocol for an extension type. + + +.. _number-structs: + +Number Object Structures +======================== + + +.. ctype:: PyNumberMethods + + Structure used to hold pointers to the functions an extension type uses to + implement the number protocol. + + +.. _sequence-structs: + +Sequence Object Structures +========================== + + +.. ctype:: PySequenceMethods + + Structure used to hold pointers to the functions which an object uses to + implement the sequence protocol. + + +.. _buffer-structs: + +Buffer Object Structures +======================== + +.. sectionauthor:: Greg J. Stein + + +The buffer interface exports a model where an object can expose its internal +data as a set of chunks of data, where each chunk is specified as a +pointer/length pair. These chunks are called :dfn:`segments` and are presumed +to be non-contiguous in memory. + +If an object does not export the buffer interface, then its :attr:`tp_as_buffer` +member in the :ctype:`PyTypeObject` structure should be *NULL*. Otherwise, the +:attr:`tp_as_buffer` will point to a :ctype:`PyBufferProcs` structure. + +.. note:: + + It is very important that your :ctype:`PyTypeObject` structure uses + :const:`Py_TPFLAGS_DEFAULT` for the value of the :attr:`tp_flags` member rather + than ``0``. This tells the Python runtime that your :ctype:`PyBufferProcs` + structure contains the :attr:`bf_getcharbuffer` slot. Older versions of Python + did not have this member, so a new Python interpreter using an old extension + needs to be able to test for its presence before using it. + + +.. ctype:: PyBufferProcs + + Structure used to hold the function pointers which define an implementation of + the buffer protocol. + + The first slot is :attr:`bf_getreadbuffer`, of type :ctype:`getreadbufferproc`. + If this slot is *NULL*, then the object does not support reading from the + internal data. This is non-sensical, so implementors should fill this in, but + callers should test that the slot contains a non-*NULL* value. + + The next slot is :attr:`bf_getwritebuffer` having type + :ctype:`getwritebufferproc`. This slot may be *NULL* if the object does not + allow writing into its returned buffers. + + The third slot is :attr:`bf_getsegcount`, with type :ctype:`getsegcountproc`. + This slot must not be *NULL* and is used to inform the caller how many segments + the object contains. Simple objects such as :ctype:`PyString_Type` and + :ctype:`PyBuffer_Type` objects contain a single segment. + + .. index:: single: PyType_HasFeature() + + The last slot is :attr:`bf_getcharbuffer`, of type :ctype:`getcharbufferproc`. + This slot will only be present if the :const:`Py_TPFLAGS_HAVE_GETCHARBUFFER` + flag is present in the :attr:`tp_flags` field of the object's + :ctype:`PyTypeObject`. Before using this slot, the caller should test whether it + is present by using the :cfunc:`PyType_HasFeature` function. If the flag is + present, :attr:`bf_getcharbuffer` may be *NULL*, indicating that the object's + contents cannot be used as *8-bit characters*. The slot function may also raise + an error if the object's contents cannot be interpreted as 8-bit characters. + For example, if the object is an array which is configured to hold floating + point values, an exception may be raised if a caller attempts to use + :attr:`bf_getcharbuffer` to fetch a sequence of 8-bit characters. This notion of + exporting the internal buffers as "text" is used to distinguish between objects + that are binary in nature, and those which have character-based content. + + .. note:: + + The current policy seems to state that these characters may be multi-byte + characters. This implies that a buffer size of *N* does not mean there are *N* + characters present. + + +.. data:: Py_TPFLAGS_HAVE_GETCHARBUFFER + + Flag bit set in the type structure to indicate that the :attr:`bf_getcharbuffer` + slot is known. This being set does not indicate that the object supports the + buffer interface or that the :attr:`bf_getcharbuffer` slot is non-*NULL*. + + +.. ctype:: Py_ssize_t (*readbufferproc) (PyObject *self, Py_ssize_t segment, void **ptrptr) + + Return a pointer to a readable segment of the buffer in ``*ptrptr``. This + function is allowed to raise an exception, in which case it must return ``-1``. + The *segment* which is specified must be zero or positive, and strictly less + than the number of segments returned by the :attr:`bf_getsegcount` slot + function. On success, it returns the length of the segment, and sets + ``*ptrptr`` to a pointer to that memory. + + +.. ctype:: Py_ssize_t (*writebufferproc) (PyObject *self, Py_ssize_t segment, void **ptrptr) + + Return a pointer to a writable memory buffer in ``*ptrptr``, and the length of + that segment as the function return value. The memory buffer must correspond to + buffer segment *segment*. Must return ``-1`` and set an exception on error. + :exc:`TypeError` should be raised if the object only supports read-only buffers, + and :exc:`SystemError` should be raised when *segment* specifies a segment that + doesn't exist. + + .. % Why doesn't it raise ValueError for this one? + .. % GJS: because you shouldn't be calling it with an invalid + .. % segment. That indicates a blatant programming error in the C + .. % code. + + +.. ctype:: Py_ssize_t (*segcountproc) (PyObject *self, Py_ssize_t *lenp) + + Return the number of memory segments which comprise the buffer. If *lenp* is + not *NULL*, the implementation must report the sum of the sizes (in bytes) of + all segments in ``*lenp``. The function cannot fail. + + +.. ctype:: Py_ssize_t (*charbufferproc) (PyObject *self, Py_ssize_t segment, const char **ptrptr) + + Return the size of the segment *segment* that *ptrptr* is set to. ``*ptrptr`` + is set to the memory buffer. Returns ``-1`` on error. + + +.. _supporting-iteration: + +Supporting the Iterator Protocol +================================ + + +.. _supporting-cycle-detection: + +Supporting Cyclic Garbage Collection +==================================== + +Python's support for detecting and collecting garbage which involves circular +references requires support from object types which are "containers" for other +objects which may also be containers. Types which do not store references to +other objects, or which only store references to atomic types (such as numbers +or strings), do not need to provide any explicit support for garbage collection. + +.. An example showing the use of these interfaces can be found in "Supporting the +.. Cycle Collector (XXX not found: ../ext/example-cycle-support.html)". + +To create a container type, the :attr:`tp_flags` field of the type object must +include the :const:`Py_TPFLAGS_HAVE_GC` and provide an implementation of the +:attr:`tp_traverse` handler. If instances of the type are mutable, a +:attr:`tp_clear` implementation must also be provided. + + +.. data:: Py_TPFLAGS_HAVE_GC + + Objects with a type with this flag set must conform with the rules documented + here. For convenience these objects will be referred to as container objects. + +Constructors for container types must conform to two rules: + +#. The memory for the object must be allocated using :cfunc:`PyObject_GC_New` or + :cfunc:`PyObject_GC_VarNew`. + +#. Once all the fields which may contain references to other containers are + initialized, it must call :cfunc:`PyObject_GC_Track`. + + +.. cfunction:: TYPE* PyObject_GC_New(TYPE, PyTypeObject *type) + + Analogous to :cfunc:`PyObject_New` but for container objects with the + :const:`Py_TPFLAGS_HAVE_GC` flag set. + + +.. cfunction:: TYPE* PyObject_GC_NewVar(TYPE, PyTypeObject *type, Py_ssize_t size) + + Analogous to :cfunc:`PyObject_NewVar` but for container objects with the + :const:`Py_TPFLAGS_HAVE_GC` flag set. + + +.. cfunction:: PyVarObject * PyObject_GC_Resize(PyVarObject *op, Py_ssize_t) + + Resize an object allocated by :cfunc:`PyObject_NewVar`. Returns the resized + object or *NULL* on failure. + + +.. cfunction:: void PyObject_GC_Track(PyObject *op) + + Adds the object *op* to the set of container objects tracked by the collector. + The collector can run at unexpected times so objects must be valid while being + tracked. This should be called once all the fields followed by the + :attr:`tp_traverse` handler become valid, usually near the end of the + constructor. + + +.. cfunction:: void _PyObject_GC_TRACK(PyObject *op) + + A macro version of :cfunc:`PyObject_GC_Track`. It should not be used for + extension modules. + +Similarly, the deallocator for the object must conform to a similar pair of +rules: + +#. Before fields which refer to other containers are invalidated, + :cfunc:`PyObject_GC_UnTrack` must be called. + +#. The object's memory must be deallocated using :cfunc:`PyObject_GC_Del`. + + +.. cfunction:: void PyObject_GC_Del(void *op) + + Releases memory allocated to an object using :cfunc:`PyObject_GC_New` or + :cfunc:`PyObject_GC_NewVar`. + + +.. cfunction:: void PyObject_GC_UnTrack(void *op) + + Remove the object *op* from the set of container objects tracked by the + collector. Note that :cfunc:`PyObject_GC_Track` can be called again on this + object to add it back to the set of tracked objects. The deallocator + (:attr:`tp_dealloc` handler) should call this for the object before any of the + fields used by the :attr:`tp_traverse` handler become invalid. + + +.. cfunction:: void _PyObject_GC_UNTRACK(PyObject *op) + + A macro version of :cfunc:`PyObject_GC_UnTrack`. It should not be used for + extension modules. + +The :attr:`tp_traverse` handler accepts a function parameter of this type: + + +.. ctype:: int (*visitproc)(PyObject *object, void *arg) + + Type of the visitor function passed to the :attr:`tp_traverse` handler. The + function should be called with an object to traverse as *object* and the third + parameter to the :attr:`tp_traverse` handler as *arg*. The Python core uses + several visitor functions to implement cyclic garbage detection; it's not + expected that users will need to write their own visitor functions. + +The :attr:`tp_traverse` handler must have the following type: + + +.. ctype:: int (*traverseproc)(PyObject *self, visitproc visit, void *arg) + + Traversal function for a container object. Implementations must call the + *visit* function for each object directly contained by *self*, with the + parameters to *visit* being the contained object and the *arg* value passed to + the handler. The *visit* function must not be called with a *NULL* object + argument. If *visit* returns a non-zero value that value should be returned + immediately. + +To simplify writing :attr:`tp_traverse` handlers, a :cfunc:`Py_VISIT` macro is +provided. In order to use this macro, the :attr:`tp_traverse` implementation +must name its arguments exactly *visit* and *arg*: + + +.. cfunction:: void Py_VISIT(PyObject *o) + + Call the *visit* callback, with arguments *o* and *arg*. If *visit* returns a + non-zero value, then return it. Using this macro, :attr:`tp_traverse` handlers + look like:: + + static int + my_traverse(Noddy *self, visitproc visit, void *arg) + { + Py_VISIT(self->foo); + Py_VISIT(self->bar); + return 0; + } + + .. versionadded:: 2.4 + +The :attr:`tp_clear` handler must be of the :ctype:`inquiry` type, or *NULL* if +the object is immutable. + + +.. ctype:: int (*inquiry)(PyObject *self) + + Drop references that may have created reference cycles. Immutable objects do + not have to define this method since they can never directly create reference + cycles. Note that the object must still be valid after calling this method + (don't just call :cfunc:`Py_DECREF` on a reference). The collector will call + this method if it detects that this object is involved in a reference cycle. + diff --git a/Doc/c-api/refcounting.rst b/Doc/c-api/refcounting.rst new file mode 100644 index 0000000..9dc357f --- /dev/null +++ b/Doc/c-api/refcounting.rst @@ -0,0 +1,74 @@ +.. highlightlang:: c + + +.. _countingrefs: + +****************** +Reference Counting +****************** + +The macros in this section are used for managing reference counts of Python +objects. + + +.. cfunction:: void Py_INCREF(PyObject *o) + + Increment the reference count for object *o*. The object must not be *NULL*; if + you aren't sure that it isn't *NULL*, use :cfunc:`Py_XINCREF`. + + +.. cfunction:: void Py_XINCREF(PyObject *o) + + Increment the reference count for object *o*. The object may be *NULL*, in + which case the macro has no effect. + + +.. cfunction:: void Py_DECREF(PyObject *o) + + Decrement the reference count for object *o*. The object must not be *NULL*; if + you aren't sure that it isn't *NULL*, use :cfunc:`Py_XDECREF`. If the reference + count reaches zero, the object's type's deallocation function (which must not be + *NULL*) is invoked. + + .. warning:: + + The deallocation function can cause arbitrary Python code to be invoked (e.g. + when a class instance with a :meth:`__del__` method is deallocated). While + exceptions in such code are not propagated, the executed code has free access to + all Python global variables. This means that any object that is reachable from + a global variable should be in a consistent state before :cfunc:`Py_DECREF` is + invoked. For example, code to delete an object from a list should copy a + reference to the deleted object in a temporary variable, update the list data + structure, and then call :cfunc:`Py_DECREF` for the temporary variable. + + +.. cfunction:: void Py_XDECREF(PyObject *o) + + Decrement the reference count for object *o*. The object may be *NULL*, in + which case the macro has no effect; otherwise the effect is the same as for + :cfunc:`Py_DECREF`, and the same warning applies. + + +.. cfunction:: void Py_CLEAR(PyObject *o) + + Decrement the reference count for object *o*. The object may be *NULL*, in + which case the macro has no effect; otherwise the effect is the same as for + :cfunc:`Py_DECREF`, except that the argument is also set to *NULL*. The warning + for :cfunc:`Py_DECREF` does not apply with respect to the object passed because + the macro carefully uses a temporary variable and sets the argument to *NULL* + before decrementing its reference count. + + It is a good idea to use this macro whenever decrementing the value of a + variable that might be traversed during garbage collection. + + .. versionadded:: 2.4 + +The following functions are for runtime dynamic embedding of Python: +``Py_IncRef(PyObject \*o)``, `Py_DecRef(PyObject \*o)``. They are +simply exported function versions of :cfunc:`Py_XINCREF` and +:cfunc:`Py_XDECREF`, respectively. + +The following functions or macros are only for use within the interpreter core: +:cfunc:`_Py_Dealloc`, :cfunc:`_Py_ForgetReference`, :cfunc:`_Py_NewReference`, +as well as the global variable :cdata:`_Py_RefTotal`. + diff --git a/Doc/c-api/utilities.rst b/Doc/c-api/utilities.rst new file mode 100644 index 0000000..01c1ceb --- /dev/null +++ b/Doc/c-api/utilities.rst @@ -0,0 +1,1030 @@ +.. highlightlang:: c + + +.. _utilities: + +********* +Utilities +********* + +The functions in this chapter perform various utility tasks, ranging from +helping C code be more portable across platforms, using Python modules from C, +and parsing function arguments and constructing Python values from C values. + + +.. _os: + +Operating System Utilities +========================== + + +.. cfunction:: int Py_FdIsInteractive(FILE *fp, const char *filename) + + Return true (nonzero) if the standard I/O file *fp* with name *filename* is + deemed interactive. This is the case for files for which ``isatty(fileno(fp))`` + is true. If the global flag :cdata:`Py_InteractiveFlag` is true, this function + also returns true if the *filename* pointer is *NULL* or if the name is equal to + one of the strings ``''`` or ``'???'``. + + +.. cfunction:: long PyOS_GetLastModificationTime(char *filename) + + Return the time of last modification of the file *filename*. The result is + encoded in the same way as the timestamp returned by the standard C library + function :cfunc:`time`. + + +.. cfunction:: void PyOS_AfterFork() + + Function to update some internal state after a process fork; this should be + called in the new process if the Python interpreter will continue to be used. + If a new executable is loaded into the new process, this function does not need + to be called. + + +.. cfunction:: int PyOS_CheckStack() + + Return true when the interpreter runs out of stack space. This is a reliable + check, but is only available when :const:`USE_STACKCHECK` is defined (currently + on Windows using the Microsoft Visual C++ compiler). :const:`USE_STACKCHECK` + will be defined automatically; you should never change the definition in your + own code. + + +.. cfunction:: PyOS_sighandler_t PyOS_getsig(int i) + + Return the current signal handler for signal *i*. This is a thin wrapper around + either :cfunc:`sigaction` or :cfunc:`signal`. Do not call those functions + directly! :ctype:`PyOS_sighandler_t` is a typedef alias for :ctype:`void + (\*)(int)`. + + +.. cfunction:: PyOS_sighandler_t PyOS_setsig(int i, PyOS_sighandler_t h) + + Set the signal handler for signal *i* to be *h*; return the old signal handler. + This is a thin wrapper around either :cfunc:`sigaction` or :cfunc:`signal`. Do + not call those functions directly! :ctype:`PyOS_sighandler_t` is a typedef + alias for :ctype:`void (\*)(int)`. + + +.. _processcontrol: + +Process Control +=============== + + +.. cfunction:: void Py_FatalError(const char *message) + + .. index:: single: abort() + + Print a fatal error message and kill the process. No cleanup is performed. + This function should only be invoked when a condition is detected that would + make it dangerous to continue using the Python interpreter; e.g., when the + object administration appears to be corrupted. On Unix, the standard C library + function :cfunc:`abort` is called which will attempt to produce a :file:`core` + file. + + +.. cfunction:: void Py_Exit(int status) + + .. index:: + single: Py_Finalize() + single: exit() + + Exit the current process. This calls :cfunc:`Py_Finalize` and then calls the + standard C library function ``exit(status)``. + + +.. cfunction:: int Py_AtExit(void (*func) ()) + + .. index:: + single: Py_Finalize() + single: cleanup functions + + Register a cleanup function to be called by :cfunc:`Py_Finalize`. The cleanup + function will be called with no arguments and should return no value. At most + 32 cleanup functions can be registered. When the registration is successful, + :cfunc:`Py_AtExit` returns ``0``; on failure, it returns ``-1``. The cleanup + function registered last is called first. Each cleanup function will be called + at most once. Since Python's internal finalization will have completed before + the cleanup function, no Python APIs should be called by *func*. + + +.. _importing: + +Importing Modules +================= + + +.. cfunction:: PyObject* PyImport_ImportModule(const char *name) + + .. index:: + single: package variable; __all__ + single: __all__ (package variable) + + This is a simplified interface to :cfunc:`PyImport_ImportModuleEx` below, + leaving the *globals* and *locals* arguments set to *NULL*. When the *name* + argument contains a dot (when it specifies a submodule of a package), the + *fromlist* argument is set to the list ``['*']`` so that the return value is the + named module rather than the top-level package containing it as would otherwise + be the case. (Unfortunately, this has an additional side effect when *name* in + fact specifies a subpackage instead of a submodule: the submodules specified in + the package's ``__all__`` variable are loaded.) Return a new reference to the + imported module, or *NULL* with an exception set on failure. Before Python 2.4, + the module may still be created in the failure case --- examine ``sys.modules`` + to find out. Starting with Python 2.4, a failing import of a module no longer + leaves the module in ``sys.modules``. + + .. versionchanged:: 2.4 + failing imports remove incomplete module objects. + + .. index:: single: modules (in module sys) + + +.. cfunction:: PyObject* PyImport_ImportModuleEx(char *name, PyObject *globals, PyObject *locals, PyObject *fromlist) + + .. index:: builtin: __import__ + + Import a module. This is best described by referring to the built-in Python + function :func:`__import__`, as the standard :func:`__import__` function calls + this function directly. + + The return value is a new reference to the imported module or top-level package, + or *NULL* with an exception set on failure (before Python 2.4, the module may + still be created in this case). Like for :func:`__import__`, the return value + when a submodule of a package was requested is normally the top-level package, + unless a non-empty *fromlist* was given. + + .. versionchanged:: 2.4 + failing imports remove incomplete module objects. + + +.. cfunction:: PyObject* PyImport_Import(PyObject *name) + + .. index:: + module: rexec + module: ihooks + + This is a higher-level interface that calls the current "import hook function". + It invokes the :func:`__import__` function from the ``__builtins__`` of the + current globals. This means that the import is done using whatever import hooks + are installed in the current environment, e.g. by :mod:`rexec` or :mod:`ihooks`. + + +.. cfunction:: PyObject* PyImport_ReloadModule(PyObject *m) + + Reload a module. Return a new reference to the reloaded module, or *NULL* with + an exception set on failure (the module still exists in this case). + + +.. cfunction:: PyObject* PyImport_AddModule(const char *name) + + Return the module object corresponding to a module name. The *name* argument + may be of the form ``package.module``. First check the modules dictionary if + there's one there, and if not, create a new one and insert it in the modules + dictionary. Return *NULL* with an exception set on failure. + + .. note:: + + This function does not load or import the module; if the module wasn't already + loaded, you will get an empty module object. Use :cfunc:`PyImport_ImportModule` + or one of its variants to import a module. Package structures implied by a + dotted name for *name* are not created if not already present. + + +.. cfunction:: PyObject* PyImport_ExecCodeModule(char *name, PyObject *co) + + .. index:: builtin: compile + + Given a module name (possibly of the form ``package.module``) and a code object + read from a Python bytecode file or obtained from the built-in function + :func:`compile`, load the module. Return a new reference to the module object, + or *NULL* with an exception set if an error occurred. Before Python 2.4, the + module could still be created in error cases. Starting with Python 2.4, *name* + is removed from ``sys.modules`` in error cases, and even if *name* was already + in ``sys.modules`` on entry to :cfunc:`PyImport_ExecCodeModule`. Leaving + incompletely initialized modules in ``sys.modules`` is dangerous, as imports of + such modules have no way to know that the module object is an unknown (and + probably damaged with respect to the module author's intents) state. + + This function will reload the module if it was already imported. See + :cfunc:`PyImport_ReloadModule` for the intended way to reload a module. + + If *name* points to a dotted name of the form ``package.module``, any package + structures not already created will still not be created. + + .. versionchanged:: 2.4 + *name* is removed from ``sys.modules`` in error cases. + + +.. cfunction:: long PyImport_GetMagicNumber() + + Return the magic number for Python bytecode files (a.k.a. :file:`.pyc` and + :file:`.pyo` files). The magic number should be present in the first four bytes + of the bytecode file, in little-endian byte order. + + +.. cfunction:: PyObject* PyImport_GetModuleDict() + + Return the dictionary used for the module administration (a.k.a. + ``sys.modules``). Note that this is a per-interpreter variable. + + +.. cfunction:: void _PyImport_Init() + + Initialize the import mechanism. For internal use only. + + +.. cfunction:: void PyImport_Cleanup() + + Empty the module table. For internal use only. + + +.. cfunction:: void _PyImport_Fini() + + Finalize the import mechanism. For internal use only. + + +.. cfunction:: PyObject* _PyImport_FindExtension(char *, char *) + + For internal use only. + + +.. cfunction:: PyObject* _PyImport_FixupExtension(char *, char *) + + For internal use only. + + +.. cfunction:: int PyImport_ImportFrozenModule(char *name) + + Load a frozen module named *name*. Return ``1`` for success, ``0`` if the + module is not found, and ``-1`` with an exception set if the initialization + failed. To access the imported module on a successful load, use + :cfunc:`PyImport_ImportModule`. (Note the misnomer --- this function would + reload the module if it was already imported.) + + +.. ctype:: struct _frozen + + .. index:: single: freeze utility + + This is the structure type definition for frozen module descriptors, as + generated by the :program:`freeze` utility (see :file:`Tools/freeze/` in the + Python source distribution). Its definition, found in :file:`Include/import.h`, + is:: + + struct _frozen { + char *name; + unsigned char *code; + int size; + }; + + +.. cvar:: struct _frozen* PyImport_FrozenModules + + This pointer is initialized to point to an array of :ctype:`struct _frozen` + records, terminated by one whose members are all *NULL* or zero. When a frozen + module is imported, it is searched in this table. Third-party code could play + tricks with this to provide a dynamically created collection of frozen modules. + + +.. cfunction:: int PyImport_AppendInittab(char *name, void (*initfunc)(void)) + + Add a single module to the existing table of built-in modules. This is a + convenience wrapper around :cfunc:`PyImport_ExtendInittab`, returning ``-1`` if + the table could not be extended. The new module can be imported by the name + *name*, and uses the function *initfunc* as the initialization function called + on the first attempted import. This should be called before + :cfunc:`Py_Initialize`. + + +.. ctype:: struct _inittab + + Structure describing a single entry in the list of built-in modules. Each of + these structures gives the name and initialization function for a module built + into the interpreter. Programs which embed Python may use an array of these + structures in conjunction with :cfunc:`PyImport_ExtendInittab` to provide + additional built-in modules. The structure is defined in + :file:`Include/import.h` as:: + + struct _inittab { + char *name; + void (*initfunc)(void); + }; + + +.. cfunction:: int PyImport_ExtendInittab(struct _inittab *newtab) + + Add a collection of modules to the table of built-in modules. The *newtab* + array must end with a sentinel entry which contains *NULL* for the :attr:`name` + field; failure to provide the sentinel value can result in a memory fault. + Returns ``0`` on success or ``-1`` if insufficient memory could be allocated to + extend the internal table. In the event of failure, no modules are added to the + internal table. This should be called before :cfunc:`Py_Initialize`. + + +.. _marshalling-utils: + +Data marshalling support +======================== + +These routines allow C code to work with serialized objects using the same data +format as the :mod:`marshal` module. There are functions to write data into the +serialization format, and additional functions that can be used to read the data +back. Files used to store marshalled data must be opened in binary mode. + +Numeric values are stored with the least significant byte first. + +The module supports two versions of the data format: version 0 is the historical +version, version 1 (new in Python 2.4) shares interned strings in the file, and +upon unmarshalling. *Py_MARSHAL_VERSION* indicates the current file format +(currently 1). + + +.. cfunction:: void PyMarshal_WriteLongToFile(long value, FILE *file, int version) + + Marshal a :ctype:`long` integer, *value*, to *file*. This will only write the + least-significant 32 bits of *value*; regardless of the size of the native + :ctype:`long` type. + + .. versionchanged:: 2.4 + *version* indicates the file format. + + +.. cfunction:: void PyMarshal_WriteObjectToFile(PyObject *value, FILE *file, int version) + + Marshal a Python object, *value*, to *file*. + + .. versionchanged:: 2.4 + *version* indicates the file format. + + +.. cfunction:: PyObject* PyMarshal_WriteObjectToString(PyObject *value, int version) + + Return a string object containing the marshalled representation of *value*. + + .. versionchanged:: 2.4 + *version* indicates the file format. + + +The following functions allow marshalled values to be read back in. + +XXX What about error detection? It appears that reading past the end of the +file will always result in a negative numeric value (where that's relevant), but +it's not clear that negative values won't be handled properly when there's no +error. What's the right way to tell? Should only non-negative values be written +using these routines? + + +.. cfunction:: long PyMarshal_ReadLongFromFile(FILE *file) + + Return a C :ctype:`long` from the data stream in a :ctype:`FILE\*` opened for + reading. Only a 32-bit value can be read in using this function, regardless of + the native size of :ctype:`long`. + + +.. cfunction:: int PyMarshal_ReadShortFromFile(FILE *file) + + Return a C :ctype:`short` from the data stream in a :ctype:`FILE\*` opened for + reading. Only a 16-bit value can be read in using this function, regardless of + the native size of :ctype:`short`. + + +.. cfunction:: PyObject* PyMarshal_ReadObjectFromFile(FILE *file) + + Return a Python object from the data stream in a :ctype:`FILE\*` opened for + reading. On error, sets the appropriate exception (:exc:`EOFError` or + :exc:`TypeError`) and returns *NULL*. + + +.. cfunction:: PyObject* PyMarshal_ReadLastObjectFromFile(FILE *file) + + Return a Python object from the data stream in a :ctype:`FILE\*` opened for + reading. Unlike :cfunc:`PyMarshal_ReadObjectFromFile`, this function assumes + that no further objects will be read from the file, allowing it to aggressively + load file data into memory so that the de-serialization can operate from data in + memory rather than reading a byte at a time from the file. Only use these + variant if you are certain that you won't be reading anything else from the + file. On error, sets the appropriate exception (:exc:`EOFError` or + :exc:`TypeError`) and returns *NULL*. + + +.. cfunction:: PyObject* PyMarshal_ReadObjectFromString(char *string, Py_ssize_t len) + + Return a Python object from the data stream in a character buffer containing + *len* bytes pointed to by *string*. On error, sets the appropriate exception + (:exc:`EOFError` or :exc:`TypeError`) and returns *NULL*. + + +.. _arg-parsing: + +Parsing arguments and building values +===================================== + +These functions are useful when creating your own extensions functions and +methods. Additional information and examples are available in +:ref:`extending-index`. + +The first three of these functions described, :cfunc:`PyArg_ParseTuple`, +:cfunc:`PyArg_ParseTupleAndKeywords`, and :cfunc:`PyArg_Parse`, all use *format +strings* which are used to tell the function about the expected arguments. The +format strings use the same syntax for each of these functions. + +A format string consists of zero or more "format units." A format unit +describes one Python object; it is usually a single character or a parenthesized +sequence of format units. With a few exceptions, a format unit that is not a +parenthesized sequence normally corresponds to a single address argument to +these functions. In the following description, the quoted form is the format +unit; the entry in (round) parentheses is the Python object type that matches +the format unit; and the entry in [square] brackets is the type of the C +variable(s) whose address should be passed. + +``s`` (string or Unicode object) [const char \*] + Convert a Python string or Unicode object to a C pointer to a character string. + You must not provide storage for the string itself; a pointer to an existing + string is stored into the character pointer variable whose address you pass. + The C string is NUL-terminated. The Python string must not contain embedded NUL + bytes; if it does, a :exc:`TypeError` exception is raised. Unicode objects are + converted to C strings using the default encoding. If this conversion fails, a + :exc:`UnicodeError` is raised. + +``s#`` (string, Unicode or any read buffer compatible object) [const char \*, int] + This variant on ``s`` stores into two C variables, the first one a pointer to a + character string, the second one its length. In this case the Python string may + contain embedded null bytes. Unicode objects pass back a pointer to the default + encoded string version of the object if such a conversion is possible. All + other read-buffer compatible objects pass back a reference to the raw internal + data representation. + +``y`` (bytes object) [const char \*] + This variant on ``s`` convert a Python bytes object to a C pointer to a + character string. The bytes object must not contain embedded NUL bytes; if it + does, a :exc:`TypeError` exception is raised. + +``y#`` (bytes object) [const char \*, int] + This variant on ``s#`` stores into two C variables, the first one a pointer to a + character string, the second one its length. This only accepts bytes objects. + +``z`` (string or ``None``) [const char \*] + Like ``s``, but the Python object may also be ``None``, in which case the C + pointer is set to *NULL*. + +``z#`` (string or ``None`` or any read buffer compatible object) [const char \*, int] + This is to ``s#`` as ``z`` is to ``s``. + +``u`` (Unicode object) [Py_UNICODE \*] + Convert a Python Unicode object to a C pointer to a NUL-terminated buffer of + 16-bit Unicode (UTF-16) data. As with ``s``, there is no need to provide + storage for the Unicode data buffer; a pointer to the existing Unicode data is + stored into the :ctype:`Py_UNICODE` pointer variable whose address you pass. + +``u#`` (Unicode object) [Py_UNICODE \*, int] + This variant on ``u`` stores into two C variables, the first one a pointer to a + Unicode data buffer, the second one its length. Non-Unicode objects are handled + by interpreting their read-buffer pointer as pointer to a :ctype:`Py_UNICODE` + array. + +``es`` (string, Unicode object or character buffer compatible object) [const char \*encoding, char \*\*buffer] + This variant on ``s`` is used for encoding Unicode and objects convertible to + Unicode into a character buffer. It only works for encoded data without embedded + NUL bytes. + + This format requires two arguments. The first is only used as input, and + must be a :ctype:`const char\*` which points to the name of an encoding as a + NUL-terminated string, or *NULL*, in which case the default encoding is used. + An exception is raised if the named encoding is not known to Python. The + second argument must be a :ctype:`char\*\*`; the value of the pointer it + references will be set to a buffer with the contents of the argument text. + The text will be encoded in the encoding specified by the first argument. + + :cfunc:`PyArg_ParseTuple` will allocate a buffer of the needed size, copy the + encoded data into this buffer and adjust *\*buffer* to reference the newly + allocated storage. The caller is responsible for calling :cfunc:`PyMem_Free` to + free the allocated buffer after use. + +``et`` (string, Unicode object or character buffer compatible object) [const char \*encoding, char \*\*buffer] + Same as ``es`` except that 8-bit string objects are passed through without + recoding them. Instead, the implementation assumes that the string object uses + the encoding passed in as parameter. + +``es#`` (string, Unicode object or character buffer compatible object) [const char \*encoding, char \*\*buffer, int \*buffer_length] + This variant on ``s#`` is used for encoding Unicode and objects convertible to + Unicode into a character buffer. Unlike the ``es`` format, this variant allows + input data which contains NUL characters. + + It requires three arguments. The first is only used as input, and must be a + :ctype:`const char\*` which points to the name of an encoding as a + NUL-terminated string, or *NULL*, in which case the default encoding is used. + An exception is raised if the named encoding is not known to Python. The + second argument must be a :ctype:`char\*\*`; the value of the pointer it + references will be set to a buffer with the contents of the argument text. + The text will be encoded in the encoding specified by the first argument. + The third argument must be a pointer to an integer; the referenced integer + will be set to the number of bytes in the output buffer. + + There are two modes of operation: + + If *\*buffer* points a *NULL* pointer, the function will allocate a buffer of + the needed size, copy the encoded data into this buffer and set *\*buffer* to + reference the newly allocated storage. The caller is responsible for calling + :cfunc:`PyMem_Free` to free the allocated buffer after usage. + + If *\*buffer* points to a non-*NULL* pointer (an already allocated buffer), + :cfunc:`PyArg_ParseTuple` will use this location as the buffer and interpret the + initial value of *\*buffer_length* as the buffer size. It will then copy the + encoded data into the buffer and NUL-terminate it. If the buffer is not large + enough, a :exc:`ValueError` will be set. + + In both cases, *\*buffer_length* is set to the length of the encoded data + without the trailing NUL byte. + +``et#`` (string, Unicode object or character buffer compatible object) [const char \*encoding, char \*\*buffer] + Same as ``es#`` except that string objects are passed through without recoding + them. Instead, the implementation assumes that the string object uses the + encoding passed in as parameter. + +``b`` (integer) [char] + Convert a Python integer to a tiny int, stored in a C :ctype:`char`. + +``B`` (integer) [unsigned char] + Convert a Python integer to a tiny int without overflow checking, stored in a C + :ctype:`unsigned char`. + + .. versionadded:: 2.3 + +``h`` (integer) [short int] + Convert a Python integer to a C :ctype:`short int`. + +``H`` (integer) [unsigned short int] + Convert a Python integer to a C :ctype:`unsigned short int`, without overflow + checking. + + .. versionadded:: 2.3 + +``i`` (integer) [int] + Convert a Python integer to a plain C :ctype:`int`. + +``I`` (integer) [unsigned int] + Convert a Python integer to a C :ctype:`unsigned int`, without overflow + checking. + + .. versionadded:: 2.3 + +``l`` (integer) [long int] + Convert a Python integer to a C :ctype:`long int`. + +``k`` (integer) [unsigned long] + Convert a Python integer or long integer to a C :ctype:`unsigned long` without + overflow checking. + + .. versionadded:: 2.3 + +``L`` (integer) [PY_LONG_LONG] + Convert a Python integer to a C :ctype:`long long`. This format is only + available on platforms that support :ctype:`long long` (or :ctype:`_int64` on + Windows). + +``K`` (integer) [unsigned PY_LONG_LONG] + Convert a Python integer or long integer to a C :ctype:`unsigned long long` + without overflow checking. This format is only available on platforms that + support :ctype:`unsigned long long` (or :ctype:`unsigned _int64` on Windows). + + .. versionadded:: 2.3 + +``n`` (integer) [Py_ssize_t] + Convert a Python integer or long integer to a C :ctype:`Py_ssize_t`. + + .. versionadded:: 2.5 + +``c`` (string of length 1) [char] + Convert a Python character, represented as a string of length 1, to a C + :ctype:`char`. + +``f`` (float) [float] + Convert a Python floating point number to a C :ctype:`float`. + +``d`` (float) [double] + Convert a Python floating point number to a C :ctype:`double`. + +``D`` (complex) [Py_complex] + Convert a Python complex number to a C :ctype:`Py_complex` structure. + +``O`` (object) [PyObject \*] + Store a Python object (without any conversion) in a C object pointer. The C + program thus receives the actual object that was passed. The object's reference + count is not increased. The pointer stored is not *NULL*. + +``O!`` (object) [*typeobject*, PyObject \*] + Store a Python object in a C object pointer. This is similar to ``O``, but + takes two C arguments: the first is the address of a Python type object, the + second is the address of the C variable (of type :ctype:`PyObject\*`) into which + the object pointer is stored. If the Python object does not have the required + type, :exc:`TypeError` is raised. + +``O&`` (object) [*converter*, *anything*] + Convert a Python object to a C variable through a *converter* function. This + takes two arguments: the first is a function, the second is the address of a C + variable (of arbitrary type), converted to :ctype:`void \*`. The *converter* + function in turn is called as follows:: + + status = converter(object, address); + + where *object* is the Python object to be converted and *address* is the + :ctype:`void\*` argument that was passed to the :cfunc:`PyArg_Parse\*` function. + The returned *status* should be ``1`` for a successful conversion and ``0`` if + the conversion has failed. When the conversion fails, the *converter* function + should raise an exception. + +``S`` (string) [PyStringObject \*] + Like ``O`` but requires that the Python object is a string object. Raises + :exc:`TypeError` if the object is not a string object. The C variable may also + be declared as :ctype:`PyObject\*`. + +``U`` (Unicode string) [PyUnicodeObject \*] + Like ``O`` but requires that the Python object is a Unicode object. Raises + :exc:`TypeError` if the object is not a Unicode object. The C variable may also + be declared as :ctype:`PyObject\*`. + +``t#`` (read-only character buffer) [char \*, int] + Like ``s#``, but accepts any object which implements the read-only buffer + interface. The :ctype:`char\*` variable is set to point to the first byte of + the buffer, and the :ctype:`int` is set to the length of the buffer. Only + single-segment buffer objects are accepted; :exc:`TypeError` is raised for all + others. + +``w`` (read-write character buffer) [char \*] + Similar to ``s``, but accepts any object which implements the read-write buffer + interface. The caller must determine the length of the buffer by other means, + or use ``w#`` instead. Only single-segment buffer objects are accepted; + :exc:`TypeError` is raised for all others. + +``w#`` (read-write character buffer) [char \*, int] + Like ``s#``, but accepts any object which implements the read-write buffer + interface. The :ctype:`char \*` variable is set to point to the first byte of + the buffer, and the :ctype:`int` is set to the length of the buffer. Only + single-segment buffer objects are accepted; :exc:`TypeError` is raised for all + others. + +``(items)`` (tuple) [*matching-items*] + The object must be a Python sequence whose length is the number of format units + in *items*. The C arguments must correspond to the individual format units in + *items*. Format units for sequences may be nested. + + .. note:: + + Prior to Python version 1.5.2, this format specifier only accepted a tuple + containing the individual parameters, not an arbitrary sequence. Code which + previously caused :exc:`TypeError` to be raised here may now proceed without an + exception. This is not expected to be a problem for existing code. + +It is possible to pass Python long integers where integers are requested; +however no proper range checking is done --- the most significant bits are +silently truncated when the receiving field is too small to receive the value +(actually, the semantics are inherited from downcasts in C --- your mileage may +vary). + +A few other characters have a meaning in a format string. These may not occur +inside nested parentheses. They are: + +``|`` + Indicates that the remaining arguments in the Python argument list are optional. + The C variables corresponding to optional arguments should be initialized to + their default value --- when an optional argument is not specified, + :cfunc:`PyArg_ParseTuple` does not touch the contents of the corresponding C + variable(s). + +``:`` + The list of format units ends here; the string after the colon is used as the + function name in error messages (the "associated value" of the exception that + :cfunc:`PyArg_ParseTuple` raises). + +``;`` + The list of format units ends here; the string after the semicolon is used as + the error message *instead* of the default error message. Clearly, ``:`` and + ``;`` mutually exclude each other. + +Note that any Python object references which are provided to the caller are +*borrowed* references; do not decrement their reference count! + +Additional arguments passed to these functions must be addresses of variables +whose type is determined by the format string; these are used to store values +from the input tuple. There are a few cases, as described in the list of format +units above, where these parameters are used as input values; they should match +what is specified for the corresponding format unit in that case. + +For the conversion to succeed, the *arg* object must match the format and the +format must be exhausted. On success, the :cfunc:`PyArg_Parse\*` functions +return true, otherwise they return false and raise an appropriate exception. + + +.. cfunction:: int PyArg_ParseTuple(PyObject *args, const char *format, ...) + + Parse the parameters of a function that takes only positional parameters into + local variables. Returns true on success; on failure, it returns false and + raises the appropriate exception. + + +.. cfunction:: int PyArg_VaParse(PyObject *args, const char *format, va_list vargs) + + Identical to :cfunc:`PyArg_ParseTuple`, except that it accepts a va_list rather + than a variable number of arguments. + + +.. cfunction:: int PyArg_ParseTupleAndKeywords(PyObject *args, PyObject *kw, const char *format, char *keywords[], ...) + + Parse the parameters of a function that takes both positional and keyword + parameters into local variables. Returns true on success; on failure, it + returns false and raises the appropriate exception. + + +.. cfunction:: int PyArg_VaParseTupleAndKeywords(PyObject *args, PyObject *kw, const char *format, char *keywords[], va_list vargs) + + Identical to :cfunc:`PyArg_ParseTupleAndKeywords`, except that it accepts a + va_list rather than a variable number of arguments. + + +.. cfunction:: int PyArg_Parse(PyObject *args, const char *format, ...) + + Function used to deconstruct the argument lists of "old-style" functions --- + these are functions which use the :const:`METH_OLDARGS` parameter parsing + method. This is not recommended for use in parameter parsing in new code, and + most code in the standard interpreter has been modified to no longer use this + for that purpose. It does remain a convenient way to decompose other tuples, + however, and may continue to be used for that purpose. + + +.. cfunction:: int PyArg_UnpackTuple(PyObject *args, const char *name, Py_ssize_t min, Py_ssize_t max, ...) + + A simpler form of parameter retrieval which does not use a format string to + specify the types of the arguments. Functions which use this method to retrieve + their parameters should be declared as :const:`METH_VARARGS` in function or + method tables. The tuple containing the actual parameters should be passed as + *args*; it must actually be a tuple. The length of the tuple must be at least + *min* and no more than *max*; *min* and *max* may be equal. Additional + arguments must be passed to the function, each of which should be a pointer to a + :ctype:`PyObject\*` variable; these will be filled in with the values from + *args*; they will contain borrowed references. The variables which correspond + to optional parameters not given by *args* will not be filled in; these should + be initialized by the caller. This function returns true on success and false if + *args* is not a tuple or contains the wrong number of elements; an exception + will be set if there was a failure. + + This is an example of the use of this function, taken from the sources for the + :mod:`_weakref` helper module for weak references:: + + static PyObject * + weakref_ref(PyObject *self, PyObject *args) + { + PyObject *object; + PyObject *callback = NULL; + PyObject *result = NULL; + + if (PyArg_UnpackTuple(args, "ref", 1, 2, &object, &callback)) { + result = PyWeakref_NewRef(object, callback); + } + return result; + } + + The call to :cfunc:`PyArg_UnpackTuple` in this example is entirely equivalent to + this call to :cfunc:`PyArg_ParseTuple`:: + + PyArg_ParseTuple(args, "O|O:ref", &object, &callback) + + .. versionadded:: 2.2 + + +.. cfunction:: PyObject* Py_BuildValue(const char *format, ...) + + Create a new value based on a format string similar to those accepted by the + :cfunc:`PyArg_Parse\*` family of functions and a sequence of values. Returns + the value or *NULL* in the case of an error; an exception will be raised if + *NULL* is returned. + + :cfunc:`Py_BuildValue` does not always build a tuple. It builds a tuple only if + its format string contains two or more format units. If the format string is + empty, it returns ``None``; if it contains exactly one format unit, it returns + whatever object is described by that format unit. To force it to return a tuple + of size 0 or one, parenthesize the format string. + + When memory buffers are passed as parameters to supply data to build objects, as + for the ``s`` and ``s#`` formats, the required data is copied. Buffers provided + by the caller are never referenced by the objects created by + :cfunc:`Py_BuildValue`. In other words, if your code invokes :cfunc:`malloc` + and passes the allocated memory to :cfunc:`Py_BuildValue`, your code is + responsible for calling :cfunc:`free` for that memory once + :cfunc:`Py_BuildValue` returns. + + In the following description, the quoted form is the format unit; the entry in + (round) parentheses is the Python object type that the format unit will return; + and the entry in [square] brackets is the type of the C value(s) to be passed. + + The characters space, tab, colon and comma are ignored in format strings (but + not within format units such as ``s#``). This can be used to make long format + strings a tad more readable. + + ``s`` (string) [char \*] + Convert a null-terminated C string to a Python object. If the C string pointer + is *NULL*, ``None`` is used. + + ``s#`` (string) [char \*, int] + Convert a C string and its length to a Python object. If the C string pointer + is *NULL*, the length is ignored and ``None`` is returned. + + ``z`` (string or ``None``) [char \*] + Same as ``s``. + + ``z#`` (string or ``None``) [char \*, int] + Same as ``s#``. + + ``u`` (Unicode string) [Py_UNICODE \*] + Convert a null-terminated buffer of Unicode (UCS-2 or UCS-4) data to a Python + Unicode object. If the Unicode buffer pointer is *NULL*, ``None`` is returned. + + ``u#`` (Unicode string) [Py_UNICODE \*, int] + Convert a Unicode (UCS-2 or UCS-4) data buffer and its length to a Python + Unicode object. If the Unicode buffer pointer is *NULL*, the length is ignored + and ``None`` is returned. + + ``U`` (string) [char \*] + Convert a null-terminated C string to a Python unicode object. If the C string + pointer is *NULL*, ``None`` is used. + + ``U#`` (string) [char \*, int] + Convert a C string and its length to a Python unicode object. If the C string + pointer is *NULL*, the length is ignored and ``None`` is returned. + + ``i`` (integer) [int] + Convert a plain C :ctype:`int` to a Python integer object. + + ``b`` (integer) [char] + Convert a plain C :ctype:`char` to a Python integer object. + + ``h`` (integer) [short int] + Convert a plain C :ctype:`short int` to a Python integer object. + + ``l`` (integer) [long int] + Convert a C :ctype:`long int` to a Python integer object. + + ``B`` (integer) [unsigned char] + Convert a C :ctype:`unsigned char` to a Python integer object. + + ``H`` (integer) [unsigned short int] + Convert a C :ctype:`unsigned short int` to a Python integer object. + + ``I`` (integer/long) [unsigned int] + Convert a C :ctype:`unsigned int` to a Python integer object or a Python long + integer object, if it is larger than ``sys.maxint``. + + ``k`` (integer/long) [unsigned long] + Convert a C :ctype:`unsigned long` to a Python integer object or a Python long + integer object, if it is larger than ``sys.maxint``. + + ``L`` (long) [PY_LONG_LONG] + Convert a C :ctype:`long long` to a Python long integer object. Only available + on platforms that support :ctype:`long long`. + + ``K`` (long) [unsigned PY_LONG_LONG] + Convert a C :ctype:`unsigned long long` to a Python long integer object. Only + available on platforms that support :ctype:`unsigned long long`. + + ``n`` (int) [Py_ssize_t] + Convert a C :ctype:`Py_ssize_t` to a Python integer or long integer. + + .. versionadded:: 2.5 + + ``c`` (string of length 1) [char] + Convert a C :ctype:`int` representing a character to a Python string of length + 1. + + ``d`` (float) [double] + Convert a C :ctype:`double` to a Python floating point number. + + ``f`` (float) [float] + Same as ``d``. + + ``D`` (complex) [Py_complex \*] + Convert a C :ctype:`Py_complex` structure to a Python complex number. + + ``O`` (object) [PyObject \*] + Pass a Python object untouched (except for its reference count, which is + incremented by one). If the object passed in is a *NULL* pointer, it is assumed + that this was caused because the call producing the argument found an error and + set an exception. Therefore, :cfunc:`Py_BuildValue` will return *NULL* but won't + raise an exception. If no exception has been raised yet, :exc:`SystemError` is + set. + + ``S`` (object) [PyObject \*] + Same as ``O``. + + ``N`` (object) [PyObject \*] + Same as ``O``, except it doesn't increment the reference count on the object. + Useful when the object is created by a call to an object constructor in the + argument list. + + ``O&`` (object) [*converter*, *anything*] + Convert *anything* to a Python object through a *converter* function. The + function is called with *anything* (which should be compatible with :ctype:`void + \*`) as its argument and should return a "new" Python object, or *NULL* if an + error occurred. + + ``(items)`` (tuple) [*matching-items*] + Convert a sequence of C values to a Python tuple with the same number of items. + + ``[items]`` (list) [*matching-items*] + Convert a sequence of C values to a Python list with the same number of items. + + ``{items}`` (dictionary) [*matching-items*] + Convert a sequence of C values to a Python dictionary. Each pair of consecutive + C values adds one item to the dictionary, serving as key and value, + respectively. + + If there is an error in the format string, the :exc:`SystemError` exception is + set and *NULL* returned. + + +.. _string-conversion: + +String conversion and formatting +================================ + +Functions for number conversion and formatted string output. + + +.. cfunction:: int PyOS_snprintf(char *str, size_t size, const char *format, ...) + + Output not more than *size* bytes to *str* according to the format string + *format* and the extra arguments. See the Unix man page :manpage:`snprintf(2)`. + + +.. cfunction:: int PyOS_vsnprintf(char *str, size_t size, const char *format, va_list va) + + Output not more than *size* bytes to *str* according to the format string + *format* and the variable argument list *va*. Unix man page + :manpage:`vsnprintf(2)`. + +:cfunc:`PyOS_snprintf` and :cfunc:`PyOS_vsnprintf` wrap the Standard C library +functions :cfunc:`snprintf` and :cfunc:`vsnprintf`. Their purpose is to +guarantee consistent behavior in corner cases, which the Standard C functions do +not. + +The wrappers ensure that *str*[*size*-1] is always ``'\0'`` upon return. They +never write more than *size* bytes (including the trailing ``'\0'``) into str. +Both functions require that ``str != NULL``, ``size > 0`` and ``format != +NULL``. + +If the platform doesn't have :cfunc:`vsnprintf` and the buffer size needed to +avoid truncation exceeds *size* by more than 512 bytes, Python aborts with a +*Py_FatalError*. + +The return value (*rv*) for these functions should be interpreted as follows: + +* When ``0 <= rv < size``, the output conversion was successful and *rv* + characters were written to *str* (excluding the trailing ``'\0'`` byte at + *str*[*rv*]). + +* When ``rv >= size``, the output conversion was truncated and a buffer with + ``rv + 1`` bytes would have been needed to succeed. *str*[*size*-1] is ``'\0'`` + in this case. + +* When ``rv < 0``, "something bad happened." *str*[*size*-1] is ``'\0'`` in + this case too, but the rest of *str* is undefined. The exact cause of the error + depends on the underlying platform. + +The following functions provide locale-independent string to number conversions. + + +.. cfunction:: double PyOS_ascii_strtod(const char *nptr, char **endptr) + + Convert a string to a :ctype:`double`. This function behaves like the Standard C + function :cfunc:`strtod` does in the C locale. It does this without changing the + current locale, since that would not be thread-safe. + + :cfunc:`PyOS_ascii_strtod` should typically be used for reading configuration + files or other non-user input that should be locale independent. + + .. versionadded:: 2.4 + + See the Unix man page :manpage:`strtod(2)` for details. + + +.. cfunction:: char * PyOS_ascii_formatd(char *buffer, size_t buf_len, const char *format, double d) + + Convert a :ctype:`double` to a string using the ``'.'`` as the decimal + separator. *format* is a :cfunc:`printf`\ -style format string specifying the + number format. Allowed conversion characters are ``'e'``, ``'E'``, ``'f'``, + ``'F'``, ``'g'`` and ``'G'``. + + The return value is a pointer to *buffer* with the converted string or NULL if + the conversion failed. + + .. versionadded:: 2.4 + + +.. cfunction:: double PyOS_ascii_atof(const char *nptr) + + Convert a string to a :ctype:`double` in a locale-independent way. + + .. versionadded:: 2.4 + + See the Unix man page :manpage:`atof(2)` for details. + diff --git a/Doc/c-api/veryhigh.rst b/Doc/c-api/veryhigh.rst new file mode 100644 index 0000000..4b26da6 --- /dev/null +++ b/Doc/c-api/veryhigh.rst @@ -0,0 +1,278 @@ +.. highlightlang:: c + + +.. _veryhigh: + +************************* +The Very High Level Layer +************************* + +The functions in this chapter will let you execute Python source code given in a +file or a buffer, but they will not let you interact in a more detailed way with +the interpreter. + +Several of these functions accept a start symbol from the grammar as a +parameter. The available start symbols are :const:`Py_eval_input`, +:const:`Py_file_input`, and :const:`Py_single_input`. These are described +following the functions which accept them as parameters. + +Note also that several of these functions take :ctype:`FILE\*` parameters. On +particular issue which needs to be handled carefully is that the :ctype:`FILE` +structure for different C libraries can be different and incompatible. Under +Windows (at least), it is possible for dynamically linked extensions to actually +use different libraries, so care should be taken that :ctype:`FILE\*` parameters +are only passed to these functions if it is certain that they were created by +the same library that the Python runtime is using. + + +.. cfunction:: int Py_Main(int argc, char **argv) + + The main program for the standard interpreter. This is made available for + programs which embed Python. The *argc* and *argv* parameters should be + prepared exactly as those which are passed to a C program's :cfunc:`main` + function. It is important to note that the argument list may be modified (but + the contents of the strings pointed to by the argument list are not). The return + value will be the integer passed to the :func:`sys.exit` function, ``1`` if the + interpreter exits due to an exception, or ``2`` if the parameter list does not + represent a valid Python command line. + + +.. cfunction:: int PyRun_AnyFile(FILE *fp, const char *filename) + + This is a simplified interface to :cfunc:`PyRun_AnyFileExFlags` below, leaving + *closeit* set to ``0`` and *flags* set to *NULL*. + + +.. cfunction:: int PyRun_AnyFileFlags(FILE *fp, const char *filename, PyCompilerFlags *flags) + + This is a simplified interface to :cfunc:`PyRun_AnyFileExFlags` below, leaving + the *closeit* argument set to ``0``. + + +.. cfunction:: int PyRun_AnyFileEx(FILE *fp, const char *filename, int closeit) + + This is a simplified interface to :cfunc:`PyRun_AnyFileExFlags` below, leaving + the *flags* argument set to *NULL*. + + +.. cfunction:: int PyRun_AnyFileExFlags(FILE *fp, const char *filename, int closeit, PyCompilerFlags *flags) + + If *fp* refers to a file associated with an interactive device (console or + terminal input or Unix pseudo-terminal), return the value of + :cfunc:`PyRun_InteractiveLoop`, otherwise return the result of + :cfunc:`PyRun_SimpleFile`. If *filename* is *NULL*, this function uses + ``"???"`` as the filename. + + +.. cfunction:: int PyRun_SimpleString(const char *command) + + This is a simplified interface to :cfunc:`PyRun_SimpleStringFlags` below, + leaving the *PyCompilerFlags\** argument set to NULL. + + +.. cfunction:: int PyRun_SimpleStringFlags(const char *command, PyCompilerFlags *flags) + + Executes the Python source code from *command* in the :mod:`__main__` module + according to the *flags* argument. If :mod:`__main__` does not already exist, it + is created. Returns ``0`` on success or ``-1`` if an exception was raised. If + there was an error, there is no way to get the exception information. For the + meaning of *flags*, see below. + + +.. cfunction:: int PyRun_SimpleFile(FILE *fp, const char *filename) + + This is a simplified interface to :cfunc:`PyRun_SimpleFileExFlags` below, + leaving *closeit* set to ``0`` and *flags* set to *NULL*. + + +.. cfunction:: int PyRun_SimpleFileFlags(FILE *fp, const char *filename, PyCompilerFlags *flags) + + This is a simplified interface to :cfunc:`PyRun_SimpleFileExFlags` below, + leaving *closeit* set to ``0``. + + +.. cfunction:: int PyRun_SimpleFileEx(FILE *fp, const char *filename, int closeit) + + This is a simplified interface to :cfunc:`PyRun_SimpleFileExFlags` below, + leaving *flags* set to *NULL*. + + +.. cfunction:: int PyRun_SimpleFileExFlags(FILE *fp, const char *filename, int closeit, PyCompilerFlags *flags) + + Similar to :cfunc:`PyRun_SimpleStringFlags`, but the Python source code is read + from *fp* instead of an in-memory string. *filename* should be the name of the + file. If *closeit* is true, the file is closed before PyRun_SimpleFileExFlags + returns. + + +.. cfunction:: int PyRun_InteractiveOne(FILE *fp, const char *filename) + + This is a simplified interface to :cfunc:`PyRun_InteractiveOneFlags` below, + leaving *flags* set to *NULL*. + + +.. cfunction:: int PyRun_InteractiveOneFlags(FILE *fp, const char *filename, PyCompilerFlags *flags) + + Read and execute a single statement from a file associated with an interactive + device according to the *flags* argument. If *filename* is *NULL*, ``"???"`` is + used instead. The user will be prompted using ``sys.ps1`` and ``sys.ps2``. + Returns ``0`` when the input was executed successfully, ``-1`` if there was an + exception, or an error code from the :file:`errcode.h` include file distributed + as part of Python if there was a parse error. (Note that :file:`errcode.h` is + not included by :file:`Python.h`, so must be included specifically if needed.) + + +.. cfunction:: int PyRun_InteractiveLoop(FILE *fp, const char *filename) + + This is a simplified interface to :cfunc:`PyRun_InteractiveLoopFlags` below, + leaving *flags* set to *NULL*. + + +.. cfunction:: int PyRun_InteractiveLoopFlags(FILE *fp, const char *filename, PyCompilerFlags *flags) + + Read and execute statements from a file associated with an interactive device + until EOF is reached. If *filename* is *NULL*, ``"???"`` is used instead. The + user will be prompted using ``sys.ps1`` and ``sys.ps2``. Returns ``0`` at EOF. + + +.. cfunction:: struct _node* PyParser_SimpleParseString(const char *str, int start) + + This is a simplified interface to + :cfunc:`PyParser_SimpleParseStringFlagsFilename` below, leaving *filename* set + to *NULL* and *flags* set to ``0``. + + +.. cfunction:: struct _node* PyParser_SimpleParseStringFlags( const char *str, int start, int flags) + + This is a simplified interface to + :cfunc:`PyParser_SimpleParseStringFlagsFilename` below, leaving *filename* set + to *NULL*. + + +.. cfunction:: struct _node* PyParser_SimpleParseStringFlagsFilename( const char *str, const char *filename, int start, int flags) + + Parse Python source code from *str* using the start token *start* according to + the *flags* argument. The result can be used to create a code object which can + be evaluated efficiently. This is useful if a code fragment must be evaluated + many times. + + +.. cfunction:: struct _node* PyParser_SimpleParseFile(FILE *fp, const char *filename, int start) + + This is a simplified interface to :cfunc:`PyParser_SimpleParseFileFlags` below, + leaving *flags* set to ``0`` + + +.. cfunction:: struct _node* PyParser_SimpleParseFileFlags(FILE *fp, const char *filename, int start, int flags) + + Similar to :cfunc:`PyParser_SimpleParseStringFlagsFilename`, but the Python + source code is read from *fp* instead of an in-memory string. + + +.. cfunction:: PyObject* PyRun_String(const char *str, int start, PyObject *globals, PyObject *locals) + + This is a simplified interface to :cfunc:`PyRun_StringFlags` below, leaving + *flags* set to *NULL*. + + +.. cfunction:: PyObject* PyRun_StringFlags(const char *str, int start, PyObject *globals, PyObject *locals, PyCompilerFlags *flags) + + Execute Python source code from *str* in the context specified by the + dictionaries *globals* and *locals* with the compiler flags specified by + *flags*. The parameter *start* specifies the start token that should be used to + parse the source code. + + Returns the result of executing the code as a Python object, or *NULL* if an + exception was raised. + + +.. cfunction:: PyObject* PyRun_File(FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals) + + This is a simplified interface to :cfunc:`PyRun_FileExFlags` below, leaving + *closeit* set to ``0`` and *flags* set to *NULL*. + + +.. cfunction:: PyObject* PyRun_FileEx(FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals, int closeit) + + This is a simplified interface to :cfunc:`PyRun_FileExFlags` below, leaving + *flags* set to *NULL*. + + +.. cfunction:: PyObject* PyRun_FileFlags(FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals, PyCompilerFlags *flags) + + This is a simplified interface to :cfunc:`PyRun_FileExFlags` below, leaving + *closeit* set to ``0``. + + +.. cfunction:: PyObject* PyRun_FileExFlags(FILE *fp, const char *filename, int start, PyObject *globals, PyObject *locals, int closeit, PyCompilerFlags *flags) + + Similar to :cfunc:`PyRun_StringFlags`, but the Python source code is read from + *fp* instead of an in-memory string. *filename* should be the name of the file. + If *closeit* is true, the file is closed before :cfunc:`PyRun_FileExFlags` + returns. + + +.. cfunction:: PyObject* Py_CompileString(const char *str, const char *filename, int start) + + This is a simplified interface to :cfunc:`Py_CompileStringFlags` below, leaving + *flags* set to *NULL*. + + +.. cfunction:: PyObject* Py_CompileStringFlags(const char *str, const char *filename, int start, PyCompilerFlags *flags) + + Parse and compile the Python source code in *str*, returning the resulting code + object. The start token is given by *start*; this can be used to constrain the + code which can be compiled and should be :const:`Py_eval_input`, + :const:`Py_file_input`, or :const:`Py_single_input`. The filename specified by + *filename* is used to construct the code object and may appear in tracebacks or + :exc:`SyntaxError` exception messages. This returns *NULL* if the code cannot + be parsed or compiled. + + +.. cvar:: int Py_eval_input + + .. index:: single: Py_CompileString() + + The start symbol from the Python grammar for isolated expressions; for use with + :cfunc:`Py_CompileString`. + + +.. cvar:: int Py_file_input + + .. index:: single: Py_CompileString() + + The start symbol from the Python grammar for sequences of statements as read + from a file or other source; for use with :cfunc:`Py_CompileString`. This is + the symbol to use when compiling arbitrarily long Python source code. + + +.. cvar:: int Py_single_input + + .. index:: single: Py_CompileString() + + The start symbol from the Python grammar for a single statement; for use with + :cfunc:`Py_CompileString`. This is the symbol used for the interactive + interpreter loop. + + +.. ctype:: struct PyCompilerFlags + + This is the structure used to hold compiler flags. In cases where code is only + being compiled, it is passed as ``int flags``, and in cases where code is being + executed, it is passed as ``PyCompilerFlags *flags``. In this case, ``from + __future__ import`` can modify *flags*. + + Whenever ``PyCompilerFlags *flags`` is *NULL*, :attr:`cf_flags` is treated as + equal to ``0``, and any modification due to ``from __future__ import`` is + discarded. :: + + struct PyCompilerFlags { + int cf_flags; + } + + +.. cvar:: int CO_FUTURE_DIVISION + + This bit can be set in *flags* to cause division operator ``/`` to be + interpreted as "true division" according to :pep:`238`. + diff --git a/Doc/conf.py b/Doc/conf.py new file mode 100644 index 0000000..6736f53 --- /dev/null +++ b/Doc/conf.py @@ -0,0 +1,56 @@ +# -*- coding: utf-8 -*- +# +# Python documentation build configuration file +# +# The contents of this file are pickled, so don't put values in the namespace +# that aren't pickleable (module imports are okay, they're removed automatically). +# + +# The default replacements for |version| and |release|. +# If 'auto', Sphinx looks for the Include/patchlevel.h file in the current Python +# source tree and replaces the values accordingly. +# +# The short X.Y version. +# version = '2.6' +version = 'auto' +# The full version, including alpha/beta/rc tags. +# release = '2.6a0' +release = 'auto' + +# There are two options for replacing |today|: either, you set today to some +# non-false value, then it is used: +today = '' +# Else, today_fmt is used as the format for a strftime call. +today_fmt = '%B %d, %Y' + +# The base URL for download links. +download_base_url = 'http://docs.python.org/ftp/python/doc/' + +# List of files that shouldn't be included in the build. +unused_files = [ + 'whatsnew/2.0.rst', + 'whatsnew/2.1.rst', + 'whatsnew/2.2.rst', + 'whatsnew/2.3.rst', + 'whatsnew/2.4.rst', + 'whatsnew/2.5.rst', + 'whatsnew/2.6.rst', + 'maclib/scrap.rst', + 'library/xmllib.rst', + 'library/xml.etree.rst', +] + +# If not '', a 'Last updated on:' timestamp is inserted at every page bottom, +# using the given strftime format. +last_updated_format = '%b %d, %Y' + +# If true, SmartyPants will be used to convert quotes and dashes to +# typographically correct entities. +use_smartypants = True + +# If true, '()' will be appended to :func: etc. cross-reference text. +add_function_parentheses = True + +# If true, the current module name will be prepended to all description +# unit titles (such as .. function::). +add_module_names = True diff --git a/Doc/contents.rst b/Doc/contents.rst new file mode 100644 index 0000000..59a72fa --- /dev/null +++ b/Doc/contents.rst @@ -0,0 +1,21 @@ +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + Python Documentation contents +%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + +.. toctree:: + + whatsnew/3.0.rst + tutorial/index.rst + reference/index.rst + library/index.rst + extending/index.rst + c-api/index.rst + distutils/index.rst + install/index.rst + documenting/index.rst + howto/index.rst + + about.rst + bugs.rst + copyright.rst + license.rst diff --git a/Doc/copyright.rst b/Doc/copyright.rst new file mode 100644 index 0000000..9a472af --- /dev/null +++ b/Doc/copyright.rst @@ -0,0 +1,19 @@ +********* +Copyright +********* + +Python and this documentation is: + +Copyright © 2001-2007 Python Software Foundation. All rights reserved. + +Copyright © 2000 BeOpen.com. All rights reserved. + +Copyright © 1995-2000 Corporation for National Research Initiatives. All rights +reserved. + +Copyright © 1991-1995 Stichting Mathematisch Centrum. All rights reserved. + +------- + +See :ref:`history-and-license` for complete license and permissions information. + diff --git a/Doc/data/refcounts.dat b/Doc/data/refcounts.dat new file mode 100644 index 0000000..5cb0b7a --- /dev/null +++ b/Doc/data/refcounts.dat @@ -0,0 +1,1747 @@ +# Created by Skip Montanaro . + +# Format: +# function ':' type ':' [param name] ':' [refcount effect] ':' [comment] +# If the param name slot is empty, that line corresponds to the function's +# return value, otherwise it's the type of the named parameter. + +# The first line of a function block gives type/refcount information for the +# function's return value. Successive lines with the same function name +# correspond to the function's parameter list and appear in the order the +# parameters appear in the function's prototype. + +# For readability, each function's lines are surrounded by a blank line. +# The blocks are sorted alphabetically by function name. + +# Refcount behavior is given for all PyObject* types: 0 (no change), +1 +# (increment) and -1 (decrement). A blank refcount field indicates the +# parameter or function value is not a PyObject* and is therefore not +# subject to reference counting. A special case for the value "null" +# (without quotes) is used for functions which return a PyObject* type but +# always return NULL. This is used by some of the PyErr_*() functions, in +# particular. + +# XXX NOTE: the 0/+1/-1 refcount information for arguments is +# confusing! Much more useful would be to indicate whether the +# function "steals" a reference to the argument or not. Take for +# example PyList_SetItem(list, i, item). This lists as a 0 change for +# both the list and the item arguments. However, in fact it steals a +# reference to the item argument! + +# The parameter names are as they appear in the API manual, not the source +# code. + +PyBool_FromLong:PyObject*::+1: +PyBool_FromLong:long:v:0: + +PyBuffer_FromObject:PyObject*::+1: +PyBuffer_FromObject:PyObject*:base:+1: +PyBuffer_FromObject:int:offset:: +PyBuffer_FromObject:int:size:: + +PyBuffer_FromReadWriteObject:PyObject*::+1: +PyBuffer_FromReadWriteObject:PyObject*:base:+1: +PyBuffer_FromReadWriteObject:int:offset:: +PyBuffer_FromReadWriteObject:int:size:: + +PyBuffer_FromMemory:PyObject*::+1: +PyBuffer_FromMemory:void*:ptr:: +PyBuffer_FromMemory:int:size:: + +PyBuffer_FromReadWriteMemory:PyObject*::+1: +PyBuffer_FromReadWriteMemory:void*:ptr:: +PyBuffer_FromReadWriteMemory:int:size:: + +PyBuffer_New:PyObject*::+1: +PyBuffer_New:int:size:: + +PyCObject_AsVoidPtr:void*::: +PyCObject_AsVoidPtr:PyObject*:self:0: + +PyCObject_FromVoidPtr:PyObject*::+1: +PyCObject_FromVoidPtr:void*:cobj:: +PyCObject_FromVoidPtr::void 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b/Doc/distutils/apiref.rst @@ -0,0 +1,1976 @@ +.. _api-reference: + +************* +API Reference +************* + + +:mod:`distutils.core` --- Core Distutils functionality +====================================================== + +.. module:: distutils.core + :synopsis: The core Distutils functionality + + +The :mod:`distutils.core` module is the only module that needs to be installed +to use the Distutils. It provides the :func:`setup` (which is called from the +setup script). Indirectly provides the :class:`distutils.dist.Distribution` and +:class:`distutils.cmd.Command` class. + + +.. function:: setup(arguments) + + The basic do-everything function that does most everything you could ever ask + for from a Distutils method. See XXXXX + + The setup function takes a large number of arguments. These are laid out in the + following table. + + +--------------------+--------------------------------+-------------------------------------------------------------+ + | argument name | value | type | + +====================+================================+=============================================================+ + | *name* | The name of the package | a string | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *version* | The version number of the | See :mod:`distutils.version` | + | | package | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *description* | A single line describing the | a string | + | | package | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *long_description* | Longer description of the | a string | + | | package | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *author* | The name of the package author | a string | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *author_email* | The email address of the | a string | + | | package author | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *maintainer* | The name of the current | a string | + | | maintainer, if different from | | + | | the author | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *maintainer_email* | The email address of the | | + | | current maintainer, if | | + | | different from the author | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *url* | A URL for the package | a URL | + | | (homepage) | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *download_url* | A URL to download the package | a URL | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *packages* | A list of Python packages that | a list of strings | + | | distutils will manipulate | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *py_modules* | A list of Python modules that | a list of strings | + | | distutils will manipulate | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *scripts* | A list of standalone script | a list of strings | + | | files to be built and | | + | | installed | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *ext_modules* | A list of Python extensions to | A list of instances of | + | | be built | :class:`distutils.core.Extension` | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *classifiers* | A list of categories for the | The list of available | + | | package | categorizations is at | + | | | http://cheeseshop.python.org/pypi?:action=list_classifiers. | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *distclass* | the :class:`Distribution` | A subclass of | + | | class to use | :class:`distutils.core.Distribution` | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *script_name* | The name of the setup.py | a string | + | | script - defaults to | | + | | ``sys.argv[0]`` | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *script_args* | Arguments to supply to the | a list of strings | + | | setup script | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *options* | default options for the setup | a string | + | | script | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *license* | The license for the package | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *keywords* | Descriptive meta-data. See | | + | | :pep:`314` | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *platforms* | | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + | *cmdclass* | A mapping of command names to | a dictionary | + | | :class:`Command` subclasses | | + +--------------------+--------------------------------+-------------------------------------------------------------+ + + +.. function:: run_setup(script_name[, script_args=None, stop_after='run']) + + Run a setup script in a somewhat controlled environment, and return the + :class:`distutils.dist.Distribution` instance that drives things. This is + useful if you need to find out the distribution meta-data (passed as keyword + args from *script* to :func:`setup`), or the contents of the config files or + command-line. + + *script_name* is a file that will be read and run with :func:`exec`. ``sys.argv[0]`` + will be replaced with *script* for the duration of the call. *script_args* is a + list of strings; if supplied, ``sys.argv[1:]`` will be replaced by *script_args* + for the duration of the call. + + *stop_after* tells :func:`setup` when to stop processing; possible values: + + +---------------+---------------------------------------------+ + | value | description | + +===============+=============================================+ + | *init* | Stop after the :class:`Distribution` | + | | instance has been created and populated | + | | with the keyword arguments to :func:`setup` | + +---------------+---------------------------------------------+ + | *config* | Stop after config files have been parsed | + | | (and their data stored in the | + | | :class:`Distribution` instance) | + +---------------+---------------------------------------------+ + | *commandline* | Stop after the command-line | + | | (``sys.argv[1:]`` or *script_args*) have | + | | been parsed (and the data stored in the | + | | :class:`Distribution` instance.) | + +---------------+---------------------------------------------+ + | *run* | Stop after all commands have been run (the | + | | same as if :func:`setup` had been called | + | | in the usual way). This is the default | + | | value. | + +---------------+---------------------------------------------+ + +In addition, the :mod:`distutils.core` module exposed a number of classes that +live elsewhere. + +* :class:`Extension` from :mod:`distutils.extension` + +* :class:`Command` from :mod:`distutils.cmd` + +* :class:`Distribution` from :mod:`distutils.dist` + +A short description of each of these follows, but see the relevant module for +the full reference. + + +.. class:: Extension + + The Extension class describes a single C or C++extension module in a setup + script. It accepts the following keyword arguments in its constructor + + +------------------------+--------------------------------+---------------------------+ + | argument name | value | type | + +========================+================================+===========================+ + | *name* | the full name of the | string | + | | extension, including any | | + | | packages --- ie. *not* a | | + | | filename or pathname, but | | + | | Python dotted name | | + +------------------------+--------------------------------+---------------------------+ + | *sources* | list of source filenames, | string | + | | relative to the distribution | | + | | root (where the setup script | | + | | lives), in Unix form (slash- | | + | | separated) for portability. | | + | | Source files may be C, C++, | | + | | SWIG (.i), platform-specific | | + | | resource files, or whatever | | + | | else is recognized by the | | + | | :command:`build_ext` command | | + | | as source for a Python | | + | | extension. | | + +------------------------+--------------------------------+---------------------------+ + | *include_dirs* | list of directories to search | string | + | | for C/C++ header files (in | | + | | Unix form for portability) | | + +------------------------+--------------------------------+---------------------------+ + | *define_macros* | list of macros to define; each | (string,string) tuple or | + | | macro is defined using a | (name,``None``) | + | | 2-tuple, where 'value' is | | + | | either the string to define it | | + | | to or ``None`` to define it | | + | | without a particular value | | + | | (equivalent of ``#define FOO`` | | + | | in source or :option:`-DFOO` | | + | | on Unix C compiler command | | + | | line) | | + +------------------------+--------------------------------+---------------------------+ + | *undef_macros* | list of macros to undefine | string | + | | explicitly | | + +------------------------+--------------------------------+---------------------------+ + | *library_dirs* | list of directories to search | string | + | | for C/C++ libraries at link | | + | | time | | + +------------------------+--------------------------------+---------------------------+ + | *libraries* | list of library names (not | string | + | | filenames or paths) to link | | + | | against | | + +------------------------+--------------------------------+---------------------------+ + | *runtime_library_dirs* | list of directories to search | string | + | | for C/C++ libraries at run | | + | | time (for shared extensions, | | + | | this is when the extension is | | + | | loaded) | | + +------------------------+--------------------------------+---------------------------+ + | *extra_objects* | list of extra files to link | string | + | | with (eg. object files not | | + | | implied by 'sources', static | | + | | library that must be | | + | | explicitly specified, binary | | + | | resource files, etc.) | | + +------------------------+--------------------------------+---------------------------+ + | *extra_compile_args* | any extra platform- and | string | + | | compiler-specific information | | + | | to use when compiling the | | + | | source files in 'sources'. For | | + | | platforms and compilers where | | + | | a command line makes sense, | | + | | this is typically a list of | | + | | command-line arguments, but | | + | | for other platforms it could | | + | | be anything. | | + +------------------------+--------------------------------+---------------------------+ + | *extra_link_args* | any extra platform- and | string | + | | compiler-specific information | | + | | to use when linking object | | + | | files together to create the | | + | | extension (or to create a new | | + | | static Python interpreter). | | + | | Similar interpretation as for | | + | | 'extra_compile_args'. | | + +------------------------+--------------------------------+---------------------------+ + | *export_symbols* | list of symbols to be exported | string | + | | from a shared extension. Not | | + | | used on all platforms, and not | | + | | generally necessary for Python | | + | | extensions, which typically | | + | | export exactly one symbol: | | + | | ``init`` + extension_name. | | + +------------------------+--------------------------------+---------------------------+ + | *depends* | list of files that the | string | + | | extension depends on | | + +------------------------+--------------------------------+---------------------------+ + | *language* | extension language (i.e. | string | + | | ``'c'``, ``'c++'``, | | + | | ``'objc'``). Will be detected | | + | | from the source extensions if | | + | | not provided. | | + +------------------------+--------------------------------+---------------------------+ + + +.. class:: Distribution + + A :class:`Distribution` describes how to build, install and package up a Python + software package. + + See the :func:`setup` function for a list of keyword arguments accepted by the + Distribution constructor. :func:`setup` creates a Distribution instance. + + +.. class:: Command + + A :class:`Command` class (or rather, an instance of one of its subclasses) + implement a single distutils command. + + +:mod:`distutils.ccompiler` --- CCompiler base class +=================================================== + +.. module:: distutils.ccompiler + :synopsis: Abstract CCompiler class + + +This module provides the abstract base class for the :class:`CCompiler` +classes. A :class:`CCompiler` instance can be used for all the compile and +link steps needed to build a single project. Methods are provided to set +options for the compiler --- macro definitions, include directories, link path, +libraries and the like. + +This module provides the following functions. + + +.. function:: gen_lib_options(compiler, library_dirs, runtime_library_dirs, libraries) + + Generate linker options for searching library directories and linking with + specific libraries. *libraries* and *library_dirs* are, respectively, lists of + library names (not filenames!) and search directories. Returns a list of + command-line options suitable for use with some compiler (depending on the two + format strings passed in). + + +.. function:: gen_preprocess_options(macros, include_dirs) + + Generate C pre-processor options (:option:`-D`, :option:`-U`, :option:`-I`) as + used by at least two types of compilers: the typical Unix compiler and Visual + C++. *macros* is the usual thing, a list of 1- or 2-tuples, where ``(name,)`` + means undefine (:option:`-U`) macro *name*, and ``(name, value)`` means define + (:option:`-D`) macro *name* to *value*. *include_dirs* is just a list of + directory names to be added to the header file search path (:option:`-I`). + Returns a list of command-line options suitable for either Unix compilers or + Visual C++. + + +.. function:: get_default_compiler(osname, platform) + + Determine the default compiler to use for the given platform. + + *osname* should be one of the standard Python OS names (i.e. the ones returned + by ``os.name``) and *platform* the common value returned by ``sys.platform`` for + the platform in question. + + The default values are ``os.name`` and ``sys.platform`` in case the parameters + are not given. + + +.. function:: new_compiler(plat=None, compiler=None, verbose=0, dry_run=0, force=0) + + Factory function to generate an instance of some CCompiler subclass for the + supplied platform/compiler combination. *plat* defaults to ``os.name`` (eg. + ``'posix'``, ``'nt'``), and *compiler* defaults to the default compiler for + that platform. Currently only ``'posix'`` and ``'nt'`` are supported, and the + default compilers are "traditional Unix interface" (:class:`UnixCCompiler` + class) and Visual C++(:class:`MSVCCompiler` class). Note that it's perfectly + possible to ask for a Unix compiler object under Windows, and a Microsoft + compiler object under Unix---if you supply a value for *compiler*, *plat* is + ignored. + + .. % Is the posix/nt only thing still true? Mac OS X seems to work, and + .. % returns a UnixCCompiler instance. How to document this... hmm. + + +.. function:: show_compilers() + + Print list of available compilers (used by the :option:`--help-compiler` options + to :command:`build`, :command:`build_ext`, :command:`build_clib`). + + +.. class:: CCompiler([verbose=0, dry_run=0, force=0]) + + The abstract base class :class:`CCompiler` defines the interface that must be + implemented by real compiler classes. The class also has some utility methods + used by several compiler classes. + + The basic idea behind a compiler abstraction class is that each instance can be + used for all the compile/link steps in building a single project. Thus, + attributes common to all of those compile and link steps --- include + directories, macros to define, libraries to link against, etc. --- are + attributes of the compiler instance. To allow for variability in how individual + files are treated, most of those attributes may be varied on a per-compilation + or per-link basis. + + The constructor for each subclass creates an instance of the Compiler object. + Flags are *verbose* (show verbose output), *dry_run* (don't actually execute the + steps) and *force* (rebuild everything, regardless of dependencies). All of + these flags default to ``0`` (off). Note that you probably don't want to + instantiate :class:`CCompiler` or one of its subclasses directly - use the + :func:`distutils.CCompiler.new_compiler` factory function instead. + + The following methods allow you to manually alter compiler options for the + instance of the Compiler class. + + + .. method:: CCompiler.add_include_dir(dir) + + Add *dir* to the list of directories that will be searched for header files. + The compiler is instructed to search directories in the order in which they are + supplied by successive calls to :meth:`add_include_dir`. + + + .. method:: CCompiler.set_include_dirs(dirs) + + Set the list of directories that will be searched to *dirs* (a list of strings). + Overrides any preceding calls to :meth:`add_include_dir`; subsequent calls to + :meth:`add_include_dir` add to the list passed to :meth:`set_include_dirs`. + This does not affect any list of standard include directories that the compiler + may search by default. + + + .. method:: CCompiler.add_library(libname) + + Add *libname* to the list of libraries that will be included in all links driven + by this compiler object. Note that *libname* should \*not\* be the name of a + file containing a library, but the name of the library itself: the actual + filename will be inferred by the linker, the compiler, or the compiler class + (depending on the platform). + + The linker will be instructed to link against libraries in the order they were + supplied to :meth:`add_library` and/or :meth:`set_libraries`. It is perfectly + valid to duplicate library names; the linker will be instructed to link against + libraries as many times as they are mentioned. + + + .. method:: CCompiler.set_libraries(libnames) + + Set the list of libraries to be included in all links driven by this compiler + object to *libnames* (a list of strings). This does not affect any standard + system libraries that the linker may include by default. + + + .. method:: CCompiler.add_library_dir(dir) + + Add *dir* to the list of directories that will be searched for libraries + specified to :meth:`add_library` and :meth:`set_libraries`. The linker will be + instructed to search for libraries in the order they are supplied to + :meth:`add_library_dir` and/or :meth:`set_library_dirs`. + + + .. method:: CCompiler.set_library_dirs(dirs) + + Set the list of library search directories to *dirs* (a list of strings). This + does not affect any standard library search path that the linker may search by + default. + + + .. method:: CCompiler.add_runtime_library_dir(dir) + + Add *dir* to the list of directories that will be searched for shared libraries + at runtime. + + + .. method:: CCompiler.set_runtime_library_dirs(dirs) + + Set the list of directories to search for shared libraries at runtime to *dirs* + (a list of strings). This does not affect any standard search path that the + runtime linker may search by default. + + + .. method:: CCompiler.define_macro(name[, value=None]) + + Define a preprocessor macro for all compilations driven by this compiler object. + The optional parameter *value* should be a string; if it is not supplied, then + the macro will be defined without an explicit value and the exact outcome + depends on the compiler used (XXX true? does ANSI say anything about this?) + + + .. method:: CCompiler.undefine_macro(name) + + Undefine a preprocessor macro for all compilations driven by this compiler + object. If the same macro is defined by :meth:`define_macro` and + undefined by :meth:`undefine_macro` the last call takes precedence + (including multiple redefinitions or undefinitions). If the macro is + redefined/undefined on a per-compilation basis (ie. in the call to + :meth:`compile`), then that takes precedence. + + + .. method:: CCompiler.add_link_object(object) + + Add *object* to the list of object files (or analogues, such as explicitly named + library files or the output of "resource compilers") to be included in every + link driven by this compiler object. + + + .. method:: CCompiler.set_link_objects(objects) + + Set the list of object files (or analogues) to be included in every link to + *objects*. This does not affect any standard object files that the linker may + include by default (such as system libraries). + + The following methods implement methods for autodetection of compiler options, + providing some functionality similar to GNU :program:`autoconf`. + + + .. method:: CCompiler.detect_language(sources) + + Detect the language of a given file, or list of files. Uses the instance + attributes :attr:`language_map` (a dictionary), and :attr:`language_order` (a + list) to do the job. + + + .. method:: CCompiler.find_library_file(dirs, lib[, debug=0]) + + Search the specified list of directories for a static or shared library file + *lib* and return the full path to that file. If *debug* is true, look for a + debugging version (if that makes sense on the current platform). Return + ``None`` if *lib* wasn't found in any of the specified directories. + + + .. method:: CCompiler.has_function(funcname [, includes=None, include_dirs=None, libraries=None, library_dirs=None]) + + Return a boolean indicating whether *funcname* is supported on the current + platform. The optional arguments can be used to augment the compilation + environment by providing additional include files and paths and libraries and + paths. + + + .. method:: CCompiler.library_dir_option(dir) + + Return the compiler option to add *dir* to the list of directories searched for + libraries. + + + .. method:: CCompiler.library_option(lib) + + Return the compiler option to add *dir* to the list of libraries linked into the + shared library or executable. + + + .. method:: CCompiler.runtime_library_dir_option(dir) + + Return the compiler option to add *dir* to the list of directories searched for + runtime libraries. + + + .. method:: CCompiler.set_executables(**args) + + Define the executables (and options for them) that will be run to perform the + various stages of compilation. The exact set of executables that may be + specified here depends on the compiler class (via the 'executables' class + attribute), but most will have: + + +--------------+------------------------------------------+ + | attribute | description | + +==============+==========================================+ + | *compiler* | the C/C++ compiler | + +--------------+------------------------------------------+ + | *linker_so* | linker used to create shared objects and | + | | libraries | + +--------------+------------------------------------------+ + | *linker_exe* | linker used to create binary executables | + +--------------+------------------------------------------+ + | *archiver* | static library creator | + +--------------+------------------------------------------+ + + On platforms with a command-line (Unix, DOS/Windows), each of these is a string + that will be split into executable name and (optional) list of arguments. + (Splitting the string is done similarly to how Unix shells operate: words are + delimited by spaces, but quotes and backslashes can override this. See + :func:`distutils.util.split_quoted`.) + + The following methods invoke stages in the build process. + + + .. method:: CCompiler.compile(sources[, output_dir=None, macros=None, include_dirs=None, debug=0, extra_preargs=None, extra_postargs=None, depends=None]) + + Compile one or more source files. Generates object files (e.g. transforms a + :file:`.c` file to a :file:`.o` file.) + + *sources* must be a list of filenames, most likely C/C++ files, but in reality + anything that can be handled by a particular compiler and compiler class (eg. + :class:`MSVCCompiler` can handle resource files in *sources*). Return a list of + object filenames, one per source filename in *sources*. Depending on the + implementation, not all source files will necessarily be compiled, but all + corresponding object filenames will be returned. + + If *output_dir* is given, object files will be put under it, while retaining + their original path component. That is, :file:`foo/bar.c` normally compiles to + :file:`foo/bar.o` (for a Unix implementation); if *output_dir* is *build*, then + it would compile to :file:`build/foo/bar.o`. + + *macros*, if given, must be a list of macro definitions. A macro definition is + either a ``(name, value)`` 2-tuple or a ``(name,)`` 1-tuple. The former defines + a macro; if the value is ``None``, the macro is defined without an explicit + value. The 1-tuple case undefines a macro. Later + definitions/redefinitions/undefinitions take precedence. + + *include_dirs*, if given, must be a list of strings, the directories to add to + the default include file search path for this compilation only. + + *debug* is a boolean; if true, the compiler will be instructed to output debug + symbols in (or alongside) the object file(s). + + *extra_preargs* and *extra_postargs* are implementation-dependent. On platforms + that have the notion of a command-line (e.g. Unix, DOS/Windows), they are most + likely lists of strings: extra command-line arguments to prepend/append to the + compiler command line. On other platforms, consult the implementation class + documentation. In any event, they are intended as an escape hatch for those + occasions when the abstract compiler framework doesn't cut the mustard. + + *depends*, if given, is a list of filenames that all targets depend on. If a + source file is older than any file in depends, then the source file will be + recompiled. This supports dependency tracking, but only at a coarse + granularity. + + Raises :exc:`CompileError` on failure. + + + .. method:: CCompiler.create_static_lib(objects, output_libname[, output_dir=None, debug=0, target_lang=None]) + + Link a bunch of stuff together to create a static library file. The "bunch of + stuff" consists of the list of object files supplied as *objects*, the extra + object files supplied to :meth:`add_link_object` and/or + :meth:`set_link_objects`, the libraries supplied to :meth:`add_library` and/or + :meth:`set_libraries`, and the libraries supplied as *libraries* (if any). + + *output_libname* should be a library name, not a filename; the filename will be + inferred from the library name. *output_dir* is the directory where the library + file will be put. XXX defaults to what? + + *debug* is a boolean; if true, debugging information will be included in the + library (note that on most platforms, it is the compile step where this matters: + the *debug* flag is included here just for consistency). + + *target_lang* is the target language for which the given objects are being + compiled. This allows specific linkage time treatment of certain languages. + + Raises :exc:`LibError` on failure. + + + .. method:: CCompiler.link(target_desc, objects, output_filename[, output_dir=None, libraries=None, library_dirs=None, runtime_library_dirs=None, export_symbols=None, debug=0, extra_preargs=None, extra_postargs=None, build_temp=None, target_lang=None]) + + Link a bunch of stuff together to create an executable or shared library file. + + The "bunch of stuff" consists of the list of object files supplied as *objects*. + *output_filename* should be a filename. If *output_dir* is supplied, + *output_filename* is relative to it (i.e. *output_filename* can provide + directory components if needed). + + *libraries* is a list of libraries to link against. These are library names, + not filenames, since they're translated into filenames in a platform-specific + way (eg. *foo* becomes :file:`libfoo.a` on Unix and :file:`foo.lib` on + DOS/Windows). However, they can include a directory component, which means the + linker will look in that specific directory rather than searching all the normal + locations. + + *library_dirs*, if supplied, should be a list of directories to search for + libraries that were specified as bare library names (ie. no directory + component). These are on top of the system default and those supplied to + :meth:`add_library_dir` and/or :meth:`set_library_dirs`. *runtime_library_dirs* + is a list of directories that will be embedded into the shared library and used + to search for other shared libraries that \*it\* depends on at run-time. (This + may only be relevant on Unix.) + + *export_symbols* is a list of symbols that the shared library will export. + (This appears to be relevant only on Windows.) + + *debug* is as for :meth:`compile` and :meth:`create_static_lib`, with the + slight distinction that it actually matters on most platforms (as opposed to + :meth:`create_static_lib`, which includes a *debug* flag mostly for form's + sake). + + *extra_preargs* and *extra_postargs* are as for :meth:`compile` (except of + course that they supply command-line arguments for the particular linker being + used). + + *target_lang* is the target language for which the given objects are being + compiled. This allows specific linkage time treatment of certain languages. + + Raises :exc:`LinkError` on failure. + + + .. method:: CCompiler.link_executable(objects, output_progname[, output_dir=None, libraries=None, library_dirs=None, runtime_library_dirs=None, debug=0, extra_preargs=None, extra_postargs=None, target_lang=None]) + + Link an executable. *output_progname* is the name of the file executable, while + *objects* are a list of object filenames to link in. Other arguments are as for + the :meth:`link` method. + + + .. method:: CCompiler.link_shared_lib(objects, output_libname[, output_dir=None, libraries=None, library_dirs=None, runtime_library_dirs=None, export_symbols=None, debug=0, extra_preargs=None, extra_postargs=None, build_temp=None, target_lang=None]) + + Link a shared library. *output_libname* is the name of the output library, + while *objects* is a list of object filenames to link in. Other arguments are + as for the :meth:`link` method. + + + .. method:: CCompiler.link_shared_object(objects, output_filename[, output_dir=None, libraries=None, library_dirs=None, runtime_library_dirs=None, export_symbols=None, debug=0, extra_preargs=None, extra_postargs=None, build_temp=None, target_lang=None]) + + Link a shared object. *output_filename* is the name of the shared object that + will be created, while *objects* is a list of object filenames to link in. + Other arguments are as for the :meth:`link` method. + + + .. method:: CCompiler.preprocess(source[, output_file=None, macros=None, include_dirs=None, extra_preargs=None, extra_postargs=None]) + + Preprocess a single C/C++ source file, named in *source*. Output will be written + to file named *output_file*, or *stdout* if *output_file* not supplied. + *macros* is a list of macro definitions as for :meth:`compile`, which will + augment the macros set with :meth:`define_macro` and :meth:`undefine_macro`. + *include_dirs* is a list of directory names that will be added to the default + list, in the same way as :meth:`add_include_dir`. + + Raises :exc:`PreprocessError` on failure. + + The following utility methods are defined by the :class:`CCompiler` class, for + use by the various concrete subclasses. + + + .. method:: CCompiler.executable_filename(basename[, strip_dir=0, output_dir='']) + + Returns the filename of the executable for the given *basename*. Typically for + non-Windows platforms this is the same as the basename, while Windows will get + a :file:`.exe` added. + + + .. method:: CCompiler.library_filename(libname[, lib_type='static', strip_dir=0, output_dir='']) + + Returns the filename for the given library name on the current platform. On Unix + a library with *lib_type* of ``'static'`` will typically be of the form + :file:`liblibname.a`, while a *lib_type* of ``'dynamic'`` will be of the form + :file:`liblibname.so`. + + + .. method:: CCompiler.object_filenames(source_filenames[, strip_dir=0, output_dir='']) + + Returns the name of the object files for the given source files. + *source_filenames* should be a list of filenames. + + + .. method:: CCompiler.shared_object_filename(basename[, strip_dir=0, output_dir='']) + + Returns the name of a shared object file for the given file name *basename*. + + + .. method:: CCompiler.execute(func, args[, msg=None, level=1]) + + Invokes :func:`distutils.util.execute` This method invokes a Python function + *func* with the given arguments *args*, after logging and taking into account + the *dry_run* flag. XXX see also. + + + .. method:: CCompiler.spawn(cmd) + + Invokes :func:`distutils.util.spawn`. This invokes an external process to run + the given command. XXX see also. + + + .. method:: CCompiler.mkpath(name[, mode=511]) + + Invokes :func:`distutils.dir_util.mkpath`. This creates a directory and any + missing ancestor directories. XXX see also. + + + .. method:: CCompiler.move_file(src, dst) + + Invokes :meth:`distutils.file_util.move_file`. Renames *src* to *dst*. XXX see + also. + + + .. method:: CCompiler.announce(msg[, level=1]) + + Write a message using :func:`distutils.log.debug`. XXX see also. + + + .. method:: CCompiler.warn(msg) + + Write a warning message *msg* to standard error. + + + .. method:: CCompiler.debug_print(msg) + + If the *debug* flag is set on this :class:`CCompiler` instance, print *msg* to + standard output, otherwise do nothing. + +.. % \subsection{Compiler-specific modules} +.. % +.. % The following modules implement concrete subclasses of the abstract +.. % \class{CCompiler} class. They should not be instantiated directly, but should +.. % be created using \function{distutils.ccompiler.new_compiler()} factory +.. % function. + + +:mod:`distutils.unixccompiler` --- Unix C Compiler +================================================== + +.. module:: distutils.unixccompiler + :synopsis: UNIX C Compiler + + +This module provides the :class:`UnixCCompiler` class, a subclass of +:class:`CCompiler` that handles the typical Unix-style command-line C compiler: + +* macros defined with :option:`-Dname[=value]` + +* macros undefined with :option:`-Uname` + +* include search directories specified with :option:`-Idir` + +* libraries specified with :option:`-llib` + +* library search directories specified with :option:`-Ldir` + +* compile handled by :program:`cc` (or similar) executable with :option:`-c` + option: compiles :file:`.c` to :file:`.o` + +* link static library handled by :program:`ar` command (possibly with + :program:`ranlib`) + +* link shared library handled by :program:`cc` :option:`-shared` + + +:mod:`distutils.msvccompiler` --- Microsoft Compiler +==================================================== + +.. module:: distutils.msvccompiler + :synopsis: Microsoft Compiler + + +This module provides :class:`MSVCCompiler`, an implementation of the abstract +:class:`CCompiler` class for Microsoft Visual Studio. Typically, extension +modules need to be compiled with the same compiler that was used to compile +Python. For Python 2.3 and earlier, the compiler was Visual Studio 6. For Python +2.4 and 2.5, the compiler is Visual Studio .NET 2003. The AMD64 and Itanium +binaries are created using the Platform SDK. + +:class:`MSVCCompiler` will normally choose the right compiler, linker etc. on +its own. To override this choice, the environment variables *DISTUTILS_USE_SDK* +and *MSSdk* must be both set. *MSSdk* indicates that the current environment has +been setup by the SDK's ``SetEnv.Cmd`` script, or that the environment variables +had been registered when the SDK was installed; *DISTUTILS_USE_SDK* indicates +that the distutils user has made an explicit choice to override the compiler +selection by :class:`MSVCCompiler`. + + +:mod:`distutils.bcppcompiler` --- Borland Compiler +================================================== + +.. module:: distutils.bcppcompiler + + +This module provides :class:`BorlandCCompiler`, an subclass of the abstract +:class:`CCompiler` class for the Borland C++ compiler. + + +:mod:`distutils.cygwincompiler` --- Cygwin Compiler +=================================================== + +.. module:: distutils.cygwinccompiler + + +This module provides the :class:`CygwinCCompiler` class, a subclass of +:class:`UnixCCompiler` that handles the Cygwin port of the GNU C compiler to +Windows. It also contains the Mingw32CCompiler class which handles the mingw32 +port of GCC (same as cygwin in no-cygwin mode). + + +:mod:`distutils.emxccompiler` --- OS/2 EMX Compiler +=================================================== + +.. module:: distutils.emxccompiler + :synopsis: OS/2 EMX Compiler support + + +This module provides the EMXCCompiler class, a subclass of +:class:`UnixCCompiler` that handles the EMX port of the GNU C compiler to OS/2. + + +:mod:`distutils.mwerkscompiler` --- Metrowerks CodeWarrior support +================================================================== + +.. module:: distutils.mwerkscompiler + :synopsis: Metrowerks CodeWarrior support + + +Contains :class:`MWerksCompiler`, an implementation of the abstract +:class:`CCompiler` class for MetroWerks CodeWarrior on the pre-Mac OS X +Macintosh. Needs work to support CW on Windows or Mac OS X. + +.. % \subsection{Utility modules} +.. % +.. % The following modules all provide general utility functions. They haven't +.. % all been documented yet. + + +:mod:`distutils.archive_util` --- Archiving utilities +====================================================== + +.. module:: distutils.archive_util + :synopsis: Utility functions for creating archive files (tarballs, zip files, ...) + + +This module provides a few functions for creating archive files, such as +tarballs or zipfiles. + + +.. function:: make_archive(base_name, format[, root_dir=None, base_dir=None, verbose=0, dry_run=0]) + + Create an archive file (eg. ``zip`` or ``tar``). *base_name* is the name of + the file to create, minus any format-specific extension; *format* is the + archive format: one of ``zip``, ``tar``, ``ztar``, or ``gztar``. *root_dir* is + a directory that will be the root directory of the archive; ie. we typically + ``chdir`` into *root_dir* before creating the archive. *base_dir* is the + directory where we start archiving from; ie. *base_dir* will be the common + prefix of all files and directories in the archive. *root_dir* and *base_dir* + both default to the current directory. Returns the name of the archive file. + + .. warning:: + + This should be changed to support bz2 files + + +.. function:: make_tarball(base_name, base_dir[, compress='gzip', verbose=0, dry_run=0]) + + 'Create an (optional compressed) archive as a tar file from all files in and + under *base_dir*. *compress* must be ``'gzip'`` (the default), ``'compress'``, + ``'bzip2'``, or ``None``. Both :program:`tar` and the compression utility named + by *compress* must be on the default program search path, so this is probably + Unix-specific. The output tar file will be named :file:`base_dir.tar`, + possibly plus the appropriate compression extension (:file:`.gz`, :file:`.bz2` + or :file:`.Z`). Return the output filename. + + .. warning:: + + This should be replaced with calls to the :mod:`tarfile` module. + + +.. function:: make_zipfile(base_name, base_dir[, verbose=0, dry_run=0]) + + Create a zip file from all files in and under *base_dir*. The output zip file + will be named *base_dir* + :file:`.zip`. Uses either the :mod:`zipfile` Python + module (if available) or the InfoZIP :file:`zip` utility (if installed and + found on the default search path). If neither tool is available, raises + :exc:`DistutilsExecError`. Returns the name of the output zip file. + + +:mod:`distutils.dep_util` --- Dependency checking +================================================= + +.. module:: distutils.dep_util + :synopsis: Utility functions for simple dependency checking + + +This module provides functions for performing simple, timestamp-based +dependency of files and groups of files; also, functions based entirely on such +timestamp dependency analysis. + + +.. function:: newer(source, target) + + Return true if *source* exists and is more recently modified than *target*, or + if *source* exists and *target* doesn't. Return false if both exist and *target* + is the same age or newer than *source*. Raise :exc:`DistutilsFileError` if + *source* does not exist. + + +.. function:: newer_pairwise(sources, targets) + + Walk two filename lists in parallel, testing if each source is newer than its + corresponding target. Return a pair of lists (*sources*, *targets*) where + source is newer than target, according to the semantics of :func:`newer` + + .. % % equivalent to a listcomp... + + +.. function:: newer_group(sources, target[, missing='error']) + + Return true if *target* is out-of-date with respect to any file listed in + *sources* In other words, if *target* exists and is newer than every file in + *sources*, return false; otherwise return true. *missing* controls what we do + when a source file is missing; the default (``'error'``) is to blow up with an + :exc:`OSError` from inside :func:`os.stat`; if it is ``'ignore'``, we silently + drop any missing source files; if it is ``'newer'``, any missing source files + make us assume that *target* is out-of-date (this is handy in "dry-run" mode: + it'll make you pretend to carry out commands that wouldn't work because inputs + are missing, but that doesn't matter because you're not actually going to run + the commands). + + +:mod:`distutils.dir_util` --- Directory tree operations +======================================================= + +.. module:: distutils.dir_util + :synopsis: Utility functions for operating on directories and directory trees + + +This module provides functions for operating on directories and trees of +directories. + + +.. function:: mkpath(name[, mode=0777, verbose=0, dry_run=0]) + + Create a directory and any missing ancestor directories. If the directory + already exists (or if *name* is the empty string, which means the current + directory, which of course exists), then do nothing. Raise + :exc:`DistutilsFileError` if unable to create some directory along the way (eg. + some sub-path exists, but is a file rather than a directory). If *verbose* is + true, print a one-line summary of each mkdir to stdout. Return the list of + directories actually created. + + +.. function:: create_tree(base_dir, files[, mode=0777, verbose=0, dry_run=0]) + + Create all the empty directories under *base_dir* needed to put *files* there. + *base_dir* is just the a name of a directory which doesn't necessarily exist + yet; *files* is a list of filenames to be interpreted relative to *base_dir*. + *base_dir* + the directory portion of every file in *files* will be created if + it doesn't already exist. *mode*, *verbose* and *dry_run* flags are as for + :func:`mkpath`. + + +.. function:: copy_tree(src, dst[, preserve_mode=1, preserve_times=1, preserve_symlinks=0, update=0, verbose=0, dry_run=0]) + + Copy an entire directory tree *src* to a new location *dst*. Both *src* and + *dst* must be directory names. If *src* is not a directory, raise + :exc:`DistutilsFileError`. If *dst* does not exist, it is created with + :func:`mkpath`. The end result of the copy is that every file in *src* is + copied to *dst*, and directories under *src* are recursively copied to *dst*. + Return the list of files that were copied or might have been copied, using their + output name. The return value is unaffected by *update* or *dry_run*: it is + simply the list of all files under *src*, with the names changed to be under + *dst*. + + *preserve_mode* and *preserve_times* are the same as for :func:`copy_file` in + :mod:`distutils.file_util`; note that they only apply to regular files, not to + directories. If *preserve_symlinks* is true, symlinks will be copied as + symlinks (on platforms that support them!); otherwise (the default), the + destination of the symlink will be copied. *update* and *verbose* are the same + as for :func:`copy_file`. + + +.. function:: remove_tree(directory[, verbose=0, dry_run=0]) + + Recursively remove *directory* and all files and directories underneath it. Any + errors are ignored (apart from being reported to ``sys.stdout`` if *verbose* is + true). + +**\*\*** Some of this could be replaced with the shutil module? **\*\*** + + +:mod:`distutils.file_util` --- Single file operations +===================================================== + +.. module:: distutils.file_util + :synopsis: Utility functions for operating on single files + + +This module contains some utility functions for operating on individual files. + + +.. function:: copy_file(src, dst[, preserve_mode=1, preserve_times=1, update=0, link=None, verbose=0, dry_run=0]) + + Copy file *src* to *dst*. If *dst* is a directory, then *src* is copied there + with the same name; otherwise, it must be a filename. (If the file exists, it + will be ruthlessly clobbered.) If *preserve_mode* is true (the default), the + file's mode (type and permission bits, or whatever is analogous on the + current platform) is copied. If *preserve_times* is true (the default), the + last-modified and last-access times are copied as well. If *update* is true, + *src* will only be copied if *dst* does not exist, or if *dst* does exist but + is older than *src*. + + *link* allows you to make hard links (using :func:`os.link`) or symbolic links + (using :func:`os.symlink`) instead of copying: set it to ``'hard'`` or + ``'sym'``; if it is ``None`` (the default), files are copied. Don't set *link* + on systems that don't support it: :func:`copy_file` doesn't check if hard or + symbolic linking is available. It uses :func:`_copy_file_contents` to copy file + contents. + + Return a tuple ``(dest_name, copied)``: *dest_name* is the actual name of the + output file, and *copied* is true if the file was copied (or would have been + copied, if *dry_run* true). + + .. % XXX if the destination file already exists, we clobber it if + .. % copying, but blow up if linking. Hmmm. And I don't know what + .. % macostools.copyfile() does. Should definitely be consistent, and + .. % should probably blow up if destination exists and we would be + .. % changing it (ie. it's not already a hard/soft link to src OR + .. % (not update) and (src newer than dst)). + + +.. function:: move_file(src, dst[, verbose, dry_run]) + + Move file *src* to *dst*. If *dst* is a directory, the file will be moved into + it with the same name; otherwise, *src* is just renamed to *dst*. Returns the + new full name of the file. + + .. warning:: + + Handles cross-device moves on Unix using :func:`copy_file`. What about other + systems??? + + +.. function:: write_file(filename, contents) + + Create a file called *filename* and write *contents* (a sequence of strings + without line terminators) to it. + + +:mod:`distutils.util` --- Miscellaneous other utility functions +=============================================================== + +.. module:: distutils.util + :synopsis: Miscellaneous other utility functions + + +This module contains other assorted bits and pieces that don't fit into any +other utility module. + + +.. function:: get_platform() + + Return a string that identifies the current platform. This is used mainly to + distinguish platform-specific build directories and platform-specific built + distributions. Typically includes the OS name and version and the architecture + (as supplied by 'os.uname()'), although the exact information included depends + on the OS; eg. for IRIX the architecture isn't particularly important (IRIX only + runs on SGI hardware), but for Linux the kernel version isn't particularly + important. + + Examples of returned values: + + * ``linux-i586`` + * ``linux-alpha`` + * ``solaris-2.6-sun4u`` + * ``irix-5.3`` + * ``irix64-6.2`` + + For non-POSIX platforms, currently just returns ``sys.platform``. + + .. % XXX isn't this also provided by some other non-distutils module? + + +.. function:: convert_path(pathname) + + Return 'pathname' as a name that will work on the native filesystem, i.e. split + it on '/' and put it back together again using the current directory separator. + Needed because filenames in the setup script are always supplied in Unix style, + and have to be converted to the local convention before we can actually use them + in the filesystem. Raises :exc:`ValueError` on non-Unix-ish systems if + *pathname* either starts or ends with a slash. + + +.. function:: change_root(new_root, pathname) + + Return *pathname* with *new_root* prepended. If *pathname* is relative, this is + equivalent to ``os.path.join(new_root,pathname)`` Otherwise, it requires making + *pathname* relative and then joining the two, which is tricky on DOS/Windows. + + +.. function:: check_environ() + + Ensure that 'os.environ' has all the environment variables we guarantee that + users can use in config files, command-line options, etc. Currently this + includes: + + * :envvar:`HOME` - user's home directory (Unix only) + * :envvar:`PLAT` - description of the current platform, including hardware and + OS (see :func:`get_platform`) + + +.. function:: subst_vars(s, local_vars) + + Perform shell/Perl-style variable substitution on *s*. Every occurrence of + ``$`` followed by a name is considered a variable, and variable is substituted + by the value found in the *local_vars* dictionary, or in ``os.environ`` if it's + not in *local_vars*. *os.environ* is first checked/augmented to guarantee that + it contains certain values: see :func:`check_environ`. Raise :exc:`ValueError` + for any variables not found in either *local_vars* or ``os.environ``. + + Note that this is not a fully-fledged string interpolation function. A valid + ``$variable`` can consist only of upper and lower case letters, numbers and an + underscore. No { } or ( ) style quoting is available. + + +.. function:: grok_environment_error(exc[, prefix='error: ']) + + Generate a useful error message from an :exc:`EnvironmentError` (:exc:`IOError` + or :exc:`OSError`) exception object. Handles Python 1.5.1 and later styles, + and does what it can to deal with exception objects that don't have a filename + (which happens when the error is due to a two-file operation, such as + :func:`rename` or :func:`link`). Returns the error message as a string + prefixed with *prefix*. + + +.. function:: split_quoted(s) + + Split a string up according to Unix shell-like rules for quotes and backslashes. + In short: words are delimited by spaces, as long as those spaces are not escaped + by a backslash, or inside a quoted string. Single and double quotes are + equivalent, and the quote characters can be backslash-escaped. The backslash is + stripped from any two-character escape sequence, leaving only the escaped + character. The quote characters are stripped from any quoted string. Returns a + list of words. + + .. % Should probably be moved into the standard library. + + +.. function:: execute(func, args[, msg=None, verbose=0, dry_run=0]) + + Perform some action that affects the outside world (for instance, writing to the + filesystem). Such actions are special because they are disabled by the + *dry_run* flag. This method takes care of all that bureaucracy for you; all + you have to do is supply the function to call and an argument tuple for it (to + embody the "external action" being performed), and an optional message to print. + + +.. function:: strtobool(val) + + Convert a string representation of truth to true (1) or false (0). + + True values are ``y``, ``yes``, ``t``, ``true``, ``on`` and ``1``; false values + are ``n``, ``no``, ``f``, ``false``, ``off`` and ``0``. Raises + :exc:`ValueError` if *val* is anything else. + + +.. function:: byte_compile(py_files[, optimize=0, force=0, prefix=None, base_dir=None, verbose=1, dry_run=0, direct=None]) + + Byte-compile a collection of Python source files to either :file:`.pyc` or + :file:`.pyo` files in the same directory. *py_files* is a list of files to + compile; any files that don't end in :file:`.py` are silently skipped. + *optimize* must be one of the following: + + * ``0`` - don't optimize (generate :file:`.pyc`) + * ``1`` - normal optimization (like ``python -O``) + * ``2`` - extra optimization (like ``python -OO``) + + If *force* is true, all files are recompiled regardless of timestamps. + + The source filename encoded in each bytecode file defaults to the filenames + listed in *py_files*; you can modify these with *prefix* and *basedir*. + *prefix* is a string that will be stripped off of each source filename, and + *base_dir* is a directory name that will be prepended (after *prefix* is + stripped). You can supply either or both (or neither) of *prefix* and + *base_dir*, as you wish. + + If *dry_run* is true, doesn't actually do anything that would affect the + filesystem. + + Byte-compilation is either done directly in this interpreter process with the + standard :mod:`py_compile` module, or indirectly by writing a temporary script + and executing it. Normally, you should let :func:`byte_compile` figure out to + use direct compilation or not (see the source for details). The *direct* flag + is used by the script generated in indirect mode; unless you know what you're + doing, leave it set to ``None``. + + +.. function:: rfc822_escape(header) + + Return a version of *header* escaped for inclusion in an :rfc:`822` header, by + ensuring there are 8 spaces space after each newline. Note that it does no other + modification of the string. + + .. % this _can_ be replaced + +.. % \subsection{Distutils objects} + + +:mod:`distutils.dist` --- The Distribution class +================================================ + +.. module:: distutils.dist + :synopsis: Provides the Distribution class, which represents the module distribution being + built/installed/distributed + + +This module provides the :class:`Distribution` class, which represents the +module distribution being built/installed/distributed. + + +:mod:`distutils.extension` --- The Extension class +================================================== + +.. module:: distutils.extension + :synopsis: Provides the Extension class, used to describe C/C++ extension modules in setup + scripts + + +This module provides the :class:`Extension` class, used to describe C/C++ +extension modules in setup scripts. + +.. % \subsection{Ungrouped modules} +.. % The following haven't been moved into a more appropriate section yet. + + +:mod:`distutils.debug` --- Distutils debug mode +=============================================== + +.. module:: distutils.debug + :synopsis: Provides the debug flag for distutils + + +This module provides the DEBUG flag. + + +:mod:`distutils.errors` --- Distutils exceptions +================================================ + +.. module:: distutils.errors + :synopsis: Provides standard distutils exceptions + + +Provides exceptions used by the Distutils modules. Note that Distutils modules +may raise standard exceptions; in particular, SystemExit is usually raised for +errors that are obviously the end-user's fault (eg. bad command-line arguments). + +This module is safe to use in ``from ... import *`` mode; it only exports +symbols whose names start with ``Distutils`` and end with ``Error``. + + +:mod:`distutils.fancy_getopt` --- Wrapper around the standard getopt module +=========================================================================== + +.. module:: distutils.fancy_getopt + :synopsis: Additional getopt functionality + + +This module provides a wrapper around the standard :mod:`getopt` module that +provides the following additional features: + +* short and long options are tied together + +* options have help strings, so :func:`fancy_getopt` could potentially create a + complete usage summary + +* options set attributes of a passed-in object + +* boolean options can have "negative aliases" --- eg. if :option:`--quiet` is + the "negative alias" of :option:`--verbose`, then :option:`--quiet` on the + command line sets *verbose* to false. + +**\*\*** Should be replaced with :mod:`optik` (which is also now known as +:mod:`optparse` in Python 2.3 and later). **\*\*** + + +.. function:: fancy_getopt(options, negative_opt, object, args) + + Wrapper function. *options* is a list of ``(long_option, short_option, + help_string)`` 3-tuples as described in the constructor for + :class:`FancyGetopt`. *negative_opt* should be a dictionary mapping option names + to option names, both the key and value should be in the *options* list. + *object* is an object which will be used to store values (see the :meth:`getopt` + method of the :class:`FancyGetopt` class). *args* is the argument list. Will use + ``sys.argv[1:]`` if you pass ``None`` as *args*. + + +.. function:: wrap_text(text, width) + + Wraps *text* to less than *width* wide. + + .. warning:: + + Should be replaced with :mod:`textwrap` (which is available in Python 2.3 and + later). + + +.. class:: FancyGetopt([option_table=None]) + + The option_table is a list of 3-tuples: ``(long_option, short_option, + help_string)`` + + If an option takes an argument, its *long_option* should have ``'='`` appended; + *short_option* should just be a single character, no ``':'`` in any case. + *short_option* should be ``None`` if a *long_option* doesn't have a + corresponding *short_option*. All option tuples must have long options. + +The :class:`FancyGetopt` class provides the following methods: + + +.. method:: FancyGetopt.getopt([args=None, object=None]) + + Parse command-line options in args. Store as attributes on *object*. + + If *args* is ``None`` or not supplied, uses ``sys.argv[1:]``. If *object* is + ``None`` or not supplied, creates a new :class:`OptionDummy` instance, stores + option values there, and returns a tuple ``(args, object)``. If *object* is + supplied, it is modified in place and :func:`getopt` just returns *args*; in + both cases, the returned *args* is a modified copy of the passed-in *args* list, + which is left untouched. + + .. % and args returned are? + + +.. method:: FancyGetopt.get_option_order() + + Returns the list of ``(option, value)`` tuples processed by the previous run of + :meth:`getopt` Raises :exc:`RuntimeError` if :meth:`getopt` hasn't been called + yet. + + +.. method:: FancyGetopt.generate_help([header=None]) + + Generate help text (a list of strings, one per suggested line of output) from + the option table for this :class:`FancyGetopt` object. + + If supplied, prints the supplied *header* at the top of the help. + + +:mod:`distutils.filelist` --- The FileList class +================================================ + +.. module:: distutils.filelist + :synopsis: The FileList class, used for poking about the file system and building lists of + files. + + +This module provides the :class:`FileList` class, used for poking about the +filesystem and building lists of files. + + +:mod:`distutils.log` --- Simple PEP 282-style logging +===================================================== + +.. module:: distutils.log + :synopsis: A simple logging mechanism, 282-style + + +.. warning:: + + Should be replaced with standard :mod:`logging` module. + +.. % \subsubsection{\module{} --- } +.. % \declaremodule{standard}{distutils.magic} +.. % \modulesynopsis{ } + + +:mod:`distutils.spawn` --- Spawn a sub-process +============================================== + +.. module:: distutils.spawn + :synopsis: Provides the spawn() function + + +This module provides the :func:`spawn` function, a front-end to various +platform-specific functions for launching another program in a sub-process. +Also provides :func:`find_executable` to search the path for a given executable +name. + + +:mod:`distutils.sysconfig` --- System configuration information +=============================================================== + +.. module:: distutils.sysconfig + :synopsis: Low-level access to configuration information of the Python interpreter. +.. moduleauthor:: Fred L. Drake, Jr. +.. moduleauthor:: Greg Ward +.. sectionauthor:: Fred L. Drake, Jr. + + +The :mod:`distutils.sysconfig` module provides access to Python's low-level +configuration information. The specific configuration variables available +depend heavily on the platform and configuration. The specific variables depend +on the build process for the specific version of Python being run; the variables +are those found in the :file:`Makefile` and configuration header that are +installed with Python on Unix systems. The configuration header is called +:file:`pyconfig.h` for Python versions starting with 2.2, and :file:`config.h` +for earlier versions of Python. + +Some additional functions are provided which perform some useful manipulations +for other parts of the :mod:`distutils` package. + + +.. data:: PREFIX + + The result of ``os.path.normpath(sys.prefix)``. + + +.. data:: EXEC_PREFIX + + The result of ``os.path.normpath(sys.exec_prefix)``. + + +.. function:: get_config_var(name) + + Return the value of a single variable. This is equivalent to + ``get_config_vars().get(name)``. + + +.. function:: get_config_vars(...) + + Return a set of variable definitions. If there are no arguments, this returns a + dictionary mapping names of configuration variables to values. If arguments are + provided, they should be strings, and the return value will be a sequence giving + the associated values. If a given name does not have a corresponding value, + ``None`` will be included for that variable. + + +.. function:: get_config_h_filename() + + Return the full path name of the configuration header. For Unix, this will be + the header generated by the :program:`configure` script; for other platforms the + header will have been supplied directly by the Python source distribution. The + file is a platform-specific text file. + + +.. function:: get_makefile_filename() + + Return the full path name of the :file:`Makefile` used to build Python. For + Unix, this will be a file generated by the :program:`configure` script; the + meaning for other platforms will vary. The file is a platform-specific text + file, if it exists. This function is only useful on POSIX platforms. + + +.. function:: get_python_inc([plat_specific[, prefix]]) + + Return the directory for either the general or platform-dependent C include + files. If *plat_specific* is true, the platform-dependent include directory is + returned; if false or omitted, the platform-independent directory is returned. + If *prefix* is given, it is used as either the prefix instead of + :const:`PREFIX`, or as the exec-prefix instead of :const:`EXEC_PREFIX` if + *plat_specific* is true. + + +.. function:: get_python_lib([plat_specific[, standard_lib[, prefix]]]) + + Return the directory for either the general or platform-dependent library + installation. If *plat_specific* is true, the platform-dependent include + directory is returned; if false or omitted, the platform-independent directory + is returned. If *prefix* is given, it is used as either the prefix instead of + :const:`PREFIX`, or as the exec-prefix instead of :const:`EXEC_PREFIX` if + *plat_specific* is true. If *standard_lib* is true, the directory for the + standard library is returned rather than the directory for the installation of + third-party extensions. + +The following function is only intended for use within the :mod:`distutils` +package. + + +.. function:: customize_compiler(compiler) + + Do any platform-specific customization of a + :class:`distutils.ccompiler.CCompiler` instance. + + This function is only needed on Unix at this time, but should be called + consistently to support forward-compatibility. It inserts the information that + varies across Unix flavors and is stored in Python's :file:`Makefile`. This + information includes the selected compiler, compiler and linker options, and the + extension used by the linker for shared objects. + +This function is even more special-purpose, and should only be used from +Python's own build procedures. + + +.. function:: set_python_build() + + Inform the :mod:`distutils.sysconfig` module that it is being used as part of + the build process for Python. This changes a lot of relative locations for + files, allowing them to be located in the build area rather than in an installed + Python. + + +:mod:`distutils.text_file` --- The TextFile class +================================================= + +.. module:: distutils.text_file + :synopsis: provides the TextFile class, a simple interface to text files + + +This module provides the :class:`TextFile` class, which gives an interface to +text files that (optionally) takes care of stripping comments, ignoring blank +lines, and joining lines with backslashes. + + +.. class:: TextFile([filename=None, file=None, **options]) + + This class provides a file-like object that takes care of all the things you + commonly want to do when processing a text file that has some line-by-line + syntax: strip comments (as long as ``#`` is your comment character), skip blank + lines, join adjacent lines by escaping the newline (ie. backslash at end of + line), strip leading and/or trailing whitespace. All of these are optional and + independently controllable. + + The class provides a :meth:`warn` method so you can generate warning messages + that report physical line number, even if the logical line in question spans + multiple physical lines. Also provides :meth:`unreadline` for implementing + line-at-a-time lookahead. + + :class:`TextFile` instances are create with either *filename*, *file*, or both. + :exc:`RuntimeError` is raised if both are ``None``. *filename* should be a + string, and *file* a file object (or something that provides :meth:`readline` + and :meth:`close` methods). It is recommended that you supply at least + *filename*, so that :class:`TextFile` can include it in warning messages. If + *file* is not supplied, :class:`TextFile` creates its own using the + :func:`open` built-in function. + + The options are all boolean, and affect the values returned by :meth:`readline` + + +------------------+--------------------------------+---------+ + | option name | description | default | + +==================+================================+=========+ + | *strip_comments* | strip from ``'#'`` to end-of- | true | + | | line, as well as any | | + | | whitespace leading up to the | | + | | ``'#'``\ ---unless it is | | + | | escaped by a backslash | | + +------------------+--------------------------------+---------+ + | *lstrip_ws* | strip leading whitespace from | false | + | | each line before returning it | | + +------------------+--------------------------------+---------+ + | *rstrip_ws* | strip trailing whitespace | true | + | | (including line terminator!) | | + | | from each line before | | + | | returning it. | | + +------------------+--------------------------------+---------+ + | *skip_blanks* | skip lines that are empty | true | + | | \*after\* stripping comments | | + | | and whitespace. (If both | | + | | lstrip_ws and rstrip_ws are | | + | | false, then some lines may | | + | | consist of solely whitespace: | | + | | these will \*not\* be skipped, | | + | | even if *skip_blanks* is | | + | | true.) | | + +------------------+--------------------------------+---------+ + | *join_lines* | if a backslash is the last | false | + | | non-newline character on a | | + | | line after stripping comments | | + | | and whitespace, join the | | + | | following line to it to form | | + | | one logical line; if N | | + | | consecutive lines end with a | | + | | backslash, then N+1 physical | | + | | lines will be joined to form | | + | | one logical line. | | + +------------------+--------------------------------+---------+ + | *collapse_join* | strip leading whitespace from | false | + | | lines that are joined to their | | + | | predecessor; only matters if | | + | | ``(join_lines and not | | + | | lstrip_ws)`` | | + +------------------+--------------------------------+---------+ + + Note that since *rstrip_ws* can strip the trailing newline, the semantics of + :meth:`readline` must differ from those of the builtin file object's + :meth:`readline` method! In particular, :meth:`readline` returns ``None`` for + end-of-file: an empty string might just be a blank line (or an all-whitespace + line), if *rstrip_ws* is true but *skip_blanks* is not. + + + .. method:: TextFile.open(filename) + + Open a new file *filename*. This overrides any *file* or *filename* constructor + arguments. + + + .. method:: TextFile.close() + + Close the current file and forget everything we know about it (including the + filename and the current line number). + + + .. method:: TextFile.warn(msg[,line=None]) + + Print (to stderr) a warning message tied to the current logical line in the + current file. If the current logical line in the file spans multiple physical + lines, the warning refers to the whole range, such as ``"lines 3-5"``. If + *line* is supplied, it overrides the current line number; it may be a list or + tuple to indicate a range of physical lines, or an integer for a single + physical line. + + + .. method:: TextFile.readline() + + Read and return a single logical line from the current file (or from an internal + buffer if lines have previously been "unread" with :meth:`unreadline`). If the + *join_lines* option is true, this may involve reading multiple physical lines + concatenated into a single string. Updates the current line number, so calling + :meth:`warn` after :meth:`readline` emits a warning about the physical line(s) + just read. Returns ``None`` on end-of-file, since the empty string can occur + if *rstrip_ws* is true but *strip_blanks* is not. + + + .. method:: TextFile.readlines() + + Read and return the list of all logical lines remaining in the current file. + This updates the current line number to the last line of the file. + + + .. method:: TextFile.unreadline(line) + + Push *line* (a string) onto an internal buffer that will be checked by future + :meth:`readline` calls. Handy for implementing a parser with line-at-a-time + lookahead. Note that lines that are "unread" with :meth:`unreadline` are not + subsequently re-cleansed (whitespace stripped, or whatever) when read with + :meth:`readline`. If multiple calls are made to :meth:`unreadline` before a call + to :meth:`readline`, the lines will be returned most in most recent first order. + + +:mod:`distutils.version` --- Version number classes +=================================================== + +.. module:: distutils.version + :synopsis: implements classes that represent module version numbers. + + +.. % todo +.. % \section{Distutils Commands} +.. % +.. % This part of Distutils implements the various Distutils commands, such +.. % as \code{build}, \code{install} \&c. Each command is implemented as a +.. % separate module, with the command name as the name of the module. + + +:mod:`distutils.cmd` --- Abstract base class for Distutils commands +=================================================================== + +.. module:: distutils.cmd + :synopsis: This module provides the abstract base class Command. This class is subclassed + by the modules in the distutils.command subpackage. + + +This module supplies the abstract base class :class:`Command`. + + +.. class:: Command(dist) + + Abstract base class for defining command classes, the "worker bees" of the + Distutils. A useful analogy for command classes is to think of them as + subroutines with local variables called *options*. The options are declared in + :meth:`initialize_options` and defined (given their final values) in + :meth:`finalize_options`, both of which must be defined by every command class. + The distinction between the two is necessary because option values might come + from the outside world (command line, config file, ...), and any options + dependent on other options must be computed after these outside influences have + been processed --- hence :meth:`finalize_options`. The body of the subroutine, + where it does all its work based on the values of its options, is the + :meth:`run` method, which must also be implemented by every command class. + + The class constructor takes a single argument *dist*, a :class:`Distribution` + instance. + + +:mod:`distutils.command` --- Individual Distutils commands +========================================================== + +.. module:: distutils.command + :synopsis: This subpackage contains one module for each standard Distutils command. + + +.. % \subsubsection{Individual Distutils commands} +.. % todo + + +:mod:`distutils.command.bdist` --- Build a binary installer +=========================================================== + +.. module:: distutils.command.bdist + :synopsis: Build a binary installer for a package + + +.. % todo + + +:mod:`distutils.command.bdist_packager` --- Abstract base class for packagers +============================================================================= + +.. module:: distutils.command.bdist_packager + :synopsis: Abstract base class for packagers + + +.. % todo + + +:mod:`distutils.command.bdist_dumb` --- Build a "dumb" installer +================================================================ + +.. module:: distutils.command.bdist_dumb + :synopsis: Build a "dumb" installer - a simple archive of files + + +.. % todo + + +:mod:`distutils.command.bdist_msi` --- Build a Microsoft Installer binary package +================================================================================= + +.. module:: distutils.command.bdist_msi + :synopsis: Build a binary distribution as a Windows MSI file + + +.. % todo + + +:mod:`distutils.command.bdist_rpm` --- Build a binary distribution as a Redhat RPM and SRPM +=========================================================================================== + +.. module:: distutils.command.bdist_rpm + :synopsis: Build a binary distribution as a Redhat RPM and SRPM + + +.. % todo + + +:mod:`distutils.command.bdist_wininst` --- Build a Windows installer +==================================================================== + +.. module:: distutils.command.bdist_wininst + :synopsis: Build a Windows installer + + +.. % todo + + +:mod:`distutils.command.sdist` --- Build a source distribution +============================================================== + +.. module:: distutils.command.sdist + :synopsis: Build a source distribution + + +.. % todo + + +:mod:`distutils.command.build` --- Build all files of a package +=============================================================== + +.. module:: distutils.command.build + :synopsis: Build all files of a package + + +.. % todo + + +:mod:`distutils.command.build_clib` --- Build any C libraries in a package +========================================================================== + +.. module:: distutils.command.build_clib + :synopsis: Build any C libraries in a package + + +.. % todo + + +:mod:`distutils.command.build_ext` --- Build any extensions in a package +======================================================================== + +.. module:: distutils.command.build_ext + :synopsis: Build any extensions in a package + + +.. % todo + + +:mod:`distutils.command.build_py` --- Build the .py/.pyc files of a package +=========================================================================== + +.. module:: distutils.command.build_py + :synopsis: Build the .py/.pyc files of a package + + +.. % todo + + +:mod:`distutils.command.build_scripts` --- Build the scripts of a package +========================================================================= + +.. module:: distutils.command.build_scripts + :synopsis: Build the scripts of a package + + +.. % todo + + +:mod:`distutils.command.clean` --- Clean a package build area +============================================================= + +.. module:: distutils.command.clean + :synopsis: Clean a package build area + + +.. % todo + + +:mod:`distutils.command.config` --- Perform package configuration +================================================================= + +.. module:: distutils.command.config + :synopsis: Perform package configuration + + +.. % todo + + +:mod:`distutils.command.install` --- Install a package +====================================================== + +.. module:: distutils.command.install + :synopsis: Install a package + + +.. % todo + + +:mod:`distutils.command.install_data` --- Install data files from a package +=========================================================================== + +.. module:: distutils.command.install_data + :synopsis: Install data files from a package + + +.. % todo + + +:mod:`distutils.command.install_headers` --- Install C/C++ header files from a package +====================================================================================== + +.. module:: distutils.command.install_headers + :synopsis: Install C/C++ header files from a package + + +.. % todo + + +:mod:`distutils.command.install_lib` --- Install library files from a package +============================================================================= + +.. module:: distutils.command.install_lib + :synopsis: Install library files from a package + + +.. % todo + + +:mod:`distutils.command.install_scripts` --- Install script files from a package +================================================================================ + +.. module:: distutils.command.install_scripts + :synopsis: Install script files from a package + + +.. % todo + + +:mod:`distutils.command.register` --- Register a module with the Python Package Index +===================================================================================== + +.. module:: distutils.command.register + :synopsis: Register a module with the Python Package Index + + +The ``register`` command registers the package with the Python Package Index. +This is described in more detail in :pep:`301`. + +.. % todo + + +Creating a new Distutils command +================================ + +This section outlines the steps to create a new Distutils command. + +A new command lives in a module in the :mod:`distutils.command` package. There +is a sample template in that directory called :file:`command_template`. Copy +this file to a new module with the same name as the new command you're +implementing. This module should implement a class with the same name as the +module (and the command). So, for instance, to create the command +``peel_banana`` (so that users can run ``setup.py peel_banana``), you'd copy +:file:`command_template` to :file:`distutils/command/peel_banana.py`, then edit +it so that it's implementing the class :class:`peel_banana`, a subclass of +:class:`distutils.cmd.Command`. + +Subclasses of :class:`Command` must define the following methods. + + +.. method:: Command.initialize_options()(S) + + et default values for all the options that this command supports. Note that + these defaults may be overridden by other commands, by the setup script, by + config files, or by the command-line. Thus, this is not the place to code + dependencies between options; generally, :meth:`initialize_options` + implementations are just a bunch of ``self.foo = None`` assignments. + + +.. method:: Command.finalize_options() + + Set final values for all the options that this command supports. This is + always called as late as possible, ie. after any option assignments from the + command-line or from other commands have been done. Thus, this is the place + to to code option dependencies: if *foo* depends on *bar*, then it is safe to + set *foo* from *bar* as long as *foo* still has the same value it was + assigned in :meth:`initialize_options`. + + +.. method:: Command.run() + + A command's raison d'etre: carry out the action it exists to perform, controlled + by the options initialized in :meth:`initialize_options`, customized by other + commands, the setup script, the command-line, and config files, and finalized in + :meth:`finalize_options`. All terminal output and filesystem interaction should + be done by :meth:`run`. + +*sub_commands* formalizes the notion of a "family" of commands, eg. ``install`` +as the parent with sub-commands ``install_lib``, ``install_headers``, etc. The +parent of a family of commands defines *sub_commands* as a class attribute; it's +a list of 2-tuples ``(command_name, predicate)``, with *command_name* a string +and *predicate* an unbound method, a string or None. *predicate* is a method of +the parent command that determines whether the corresponding command is +applicable in the current situation. (Eg. we ``install_headers`` is only +applicable if we have any C header files to install.) If *predicate* is None, +that command is always applicable. + +*sub_commands* is usually defined at the \*end\* of a class, because predicates +can be unbound methods, so they must already have been defined. The canonical +example is the :command:`install` command. diff --git a/Doc/distutils/builtdist.rst b/Doc/distutils/builtdist.rst new file mode 100644 index 0000000..b40ddeb --- /dev/null +++ b/Doc/distutils/builtdist.rst @@ -0,0 +1,405 @@ +.. _built-dist: + +**************************** +Creating Built Distributions +**************************** + +A "built distribution" is what you're probably used to thinking of either as a +"binary package" or an "installer" (depending on your background). It's not +necessarily binary, though, because it might contain only Python source code +and/or byte-code; and we don't call it a package, because that word is already +spoken for in Python. (And "installer" is a term specific to the world of +mainstream desktop systems.) + +A built distribution is how you make life as easy as possible for installers of +your module distribution: for users of RPM-based Linux systems, it's a binary +RPM; for Windows users, it's an executable installer; for Debian-based Linux +users, it's a Debian package; and so forth. Obviously, no one person will be +able to create built distributions for every platform under the sun, so the +Distutils are designed to enable module developers to concentrate on their +specialty---writing code and creating source distributions---while an +intermediary species called *packagers* springs up to turn source distributions +into built distributions for as many platforms as there are packagers. + +Of course, the module developer could be his own packager; or the packager could +be a volunteer "out there" somewhere who has access to a platform which the +original developer does not; or it could be software periodically grabbing new +source distributions and turning them into built distributions for as many +platforms as the software has access to. Regardless of who they are, a packager +uses the setup script and the :command:`bdist` command family to generate built +distributions. + +As a simple example, if I run the following command in the Distutils source +tree:: + + python setup.py bdist + +then the Distutils builds my module distribution (the Distutils itself in this +case), does a "fake" installation (also in the :file:`build` directory), and +creates the default type of built distribution for my platform. The default +format for built distributions is a "dumb" tar file on Unix, and a simple +executable installer on Windows. (That tar file is considered "dumb" because it +has to be unpacked in a specific location to work.) + +Thus, the above command on a Unix system creates +:file:`Distutils-1.0.{plat}.tar.gz`; unpacking this tarball from the right place +installs the Distutils just as though you had downloaded the source distribution +and run ``python setup.py install``. (The "right place" is either the root of +the filesystem or Python's :file:`{prefix}` directory, depending on the options +given to the :command:`bdist_dumb` command; the default is to make dumb +distributions relative to :file:`{prefix}`.) + +Obviously, for pure Python distributions, this isn't any simpler than just +running ``python setup.py install``\ ---but for non-pure distributions, which +include extensions that would need to be compiled, it can mean the difference +between someone being able to use your extensions or not. And creating "smart" +built distributions, such as an RPM package or an executable installer for +Windows, is far more convenient for users even if your distribution doesn't +include any extensions. + +The :command:`bdist` command has a :option:`--formats` option, similar to the +:command:`sdist` command, which you can use to select the types of built +distribution to generate: for example, :: + + python setup.py bdist --format=zip + +would, when run on a Unix system, create :file:`Distutils-1.0.{plat}.zip`\ +---again, this archive would be unpacked from the root directory to install the +Distutils. + +The available formats for built distributions are: + ++-------------+------------------------------+---------+ +| Format | Description | Notes | ++=============+==============================+=========+ +| ``gztar`` | gzipped tar file | (1),(3) | +| | (:file:`.tar.gz`) | | ++-------------+------------------------------+---------+ +| ``ztar`` | compressed tar file | \(3) | +| | (:file:`.tar.Z`) | | ++-------------+------------------------------+---------+ +| ``tar`` | tar file (:file:`.tar`) | \(3) | ++-------------+------------------------------+---------+ +| ``zip`` | zip file (:file:`.zip`) | \(4) | ++-------------+------------------------------+---------+ +| ``rpm`` | RPM | \(5) | ++-------------+------------------------------+---------+ +| ``pkgtool`` | Solaris :program:`pkgtool` | | ++-------------+------------------------------+---------+ +| ``sdux`` | HP-UX :program:`swinstall` | | ++-------------+------------------------------+---------+ +| ``rpm`` | RPM | \(5) | ++-------------+------------------------------+---------+ +| ``wininst`` | self-extracting ZIP file for | (2),(4) | +| | Windows | | ++-------------+------------------------------+---------+ + +Notes: + +(1) + default on Unix + +(2) + default on Windows + + **\*\*** to-do! **\*\*** + +(3) + requires external utilities: :program:`tar` and possibly one of :program:`gzip`, + :program:`bzip2`, or :program:`compress` + +(4) + requires either external :program:`zip` utility or :mod:`zipfile` module (part + of the standard Python library since Python 1.6) + +(5) + requires external :program:`rpm` utility, version 3.0.4 or better (use ``rpm + --version`` to find out which version you have) + +You don't have to use the :command:`bdist` command with the :option:`--formats` +option; you can also use the command that directly implements the format you're +interested in. Some of these :command:`bdist` "sub-commands" actually generate +several similar formats; for instance, the :command:`bdist_dumb` command +generates all the "dumb" archive formats (``tar``, ``ztar``, ``gztar``, and +``zip``), and :command:`bdist_rpm` generates both binary and source RPMs. The +:command:`bdist` sub-commands, and the formats generated by each, are: + ++--------------------------+-----------------------+ +| Command | Formats | ++==========================+=======================+ +| :command:`bdist_dumb` | tar, ztar, gztar, zip | ++--------------------------+-----------------------+ +| :command:`bdist_rpm` | rpm, srpm | ++--------------------------+-----------------------+ +| :command:`bdist_wininst` | wininst | ++--------------------------+-----------------------+ + +The following sections give details on the individual :command:`bdist_\*` +commands. + + +.. _creating-dumb: + +Creating dumb built distributions +================================= + +**\*\*** Need to document absolute vs. prefix-relative packages here, but first +I have to implement it! **\*\*** + + +.. _creating-rpms: + +Creating RPM packages +===================== + +The RPM format is used by many popular Linux distributions, including Red Hat, +SuSE, and Mandrake. If one of these (or any of the other RPM-based Linux +distributions) is your usual environment, creating RPM packages for other users +of that same distribution is trivial. Depending on the complexity of your module +distribution and differences between Linux distributions, you may also be able +to create RPMs that work on different RPM-based distributions. + +The usual way to create an RPM of your module distribution is to run the +:command:`bdist_rpm` command:: + + python setup.py bdist_rpm + +or the :command:`bdist` command with the :option:`--format` option:: + + python setup.py bdist --formats=rpm + +The former allows you to specify RPM-specific options; the latter allows you to +easily specify multiple formats in one run. If you need to do both, you can +explicitly specify multiple :command:`bdist_\*` commands and their options:: + + python setup.py bdist_rpm --packager="John Doe " \ + bdist_wininst --target_version="2.0" + +Creating RPM packages is driven by a :file:`.spec` file, much as using the +Distutils is driven by the setup script. To make your life easier, the +:command:`bdist_rpm` command normally creates a :file:`.spec` file based on the +information you supply in the setup script, on the command line, and in any +Distutils configuration files. Various options and sections in the +:file:`.spec` file are derived from options in the setup script as follows: + ++------------------------------------------+----------------------------------------------+ +| RPM :file:`.spec` file option or section | Distutils setup script option | ++==========================================+==============================================+ +| Name | :option:`name` | ++------------------------------------------+----------------------------------------------+ +| Summary (in preamble) | :option:`description` | ++------------------------------------------+----------------------------------------------+ +| Version | :option:`version` | ++------------------------------------------+----------------------------------------------+ +| Vendor | :option:`author` and :option:`author_email`, | +| | or --- & :option:`maintainer` and | +| | :option:`maintainer_email` | ++------------------------------------------+----------------------------------------------+ +| Copyright | :option:`licence` | ++------------------------------------------+----------------------------------------------+ +| Url | :option:`url` | ++------------------------------------------+----------------------------------------------+ +| %description (section) | :option:`long_description` | ++------------------------------------------+----------------------------------------------+ + +Additionally, there are many options in :file:`.spec` files that don't have +corresponding options in the setup script. Most of these are handled through +options to the :command:`bdist_rpm` command as follows: + ++-------------------------------+-----------------------------+-------------------------+ +| RPM :file:`.spec` file option | :command:`bdist_rpm` option | default value | +| or section | | | ++===============================+=============================+=========================+ +| Release | :option:`release` | "1" | ++-------------------------------+-----------------------------+-------------------------+ +| Group | :option:`group` | "Development/Libraries" | ++-------------------------------+-----------------------------+-------------------------+ +| Vendor | :option:`vendor` | (see above) | ++-------------------------------+-----------------------------+-------------------------+ +| Packager | :option:`packager` | (none) | ++-------------------------------+-----------------------------+-------------------------+ +| Provides | :option:`provides` | (none) | ++-------------------------------+-----------------------------+-------------------------+ +| Requires | :option:`requires` | (none) | ++-------------------------------+-----------------------------+-------------------------+ +| Conflicts | :option:`conflicts` | (none) | ++-------------------------------+-----------------------------+-------------------------+ +| Obsoletes | :option:`obsoletes` | (none) | ++-------------------------------+-----------------------------+-------------------------+ +| Distribution | :option:`distribution_name` | (none) | ++-------------------------------+-----------------------------+-------------------------+ +| BuildRequires | :option:`build_requires` | (none) | ++-------------------------------+-----------------------------+-------------------------+ +| Icon | :option:`icon` | (none) | ++-------------------------------+-----------------------------+-------------------------+ + +Obviously, supplying even a few of these options on the command-line would be +tedious and error-prone, so it's usually best to put them in the setup +configuration file, :file:`setup.cfg`\ ---see section :ref:`setup-config`. If +you distribute or package many Python module distributions, you might want to +put options that apply to all of them in your personal Distutils configuration +file (:file:`~/.pydistutils.cfg`). + +There are three steps to building a binary RPM package, all of which are +handled automatically by the Distutils: + +#. create a :file:`.spec` file, which describes the package (analogous to the + Distutils setup script; in fact, much of the information in the setup script + winds up in the :file:`.spec` file) + +#. create the source RPM + +#. create the "binary" RPM (which may or may not contain binary code, depending + on whether your module distribution contains Python extensions) + +Normally, RPM bundles the last two steps together; when you use the Distutils, +all three steps are typically bundled together. + +If you wish, you can separate these three steps. You can use the +:option:`--spec-only` option to make :command:`bdist_rpm` just create the +:file:`.spec` file and exit; in this case, the :file:`.spec` file will be +written to the "distribution directory"---normally :file:`dist/`, but +customizable with the :option:`--dist-dir` option. (Normally, the :file:`.spec` +file winds up deep in the "build tree," in a temporary directory created by +:command:`bdist_rpm`.) + +.. % \XXX{this isn't implemented yet---is it needed?!} +.. % You can also specify a custom \file{.spec} file with the +.. % \longprogramopt{spec-file} option; used in conjunction with +.. % \longprogramopt{spec-only}, this gives you an opportunity to customize +.. % the \file{.spec} file manually: +.. % +.. % \ begin{verbatim} +.. % > python setup.py bdist_rpm --spec-only +.. % # ...edit dist/FooBar-1.0.spec +.. % > python setup.py bdist_rpm --spec-file=dist/FooBar-1.0.spec +.. % \ end{verbatim} +.. % +.. % (Although a better way to do this is probably to override the standard +.. % \command{bdist\_rpm} command with one that writes whatever else you want +.. % to the \file{.spec} file.) + + +.. _creating-wininst: + +Creating Windows Installers +=========================== + +Executable installers are the natural format for binary distributions on +Windows. They display a nice graphical user interface, display some information +about the module distribution to be installed taken from the metadata in the +setup script, let the user select a few options, and start or cancel the +installation. + +Since the metadata is taken from the setup script, creating Windows installers +is usually as easy as running:: + + python setup.py bdist_wininst + +or the :command:`bdist` command with the :option:`--formats` option:: + + python setup.py bdist --formats=wininst + +If you have a pure module distribution (only containing pure Python modules and +packages), the resulting installer will be version independent and have a name +like :file:`foo-1.0.win32.exe`. These installers can even be created on Unix or +Mac OS platforms. + +If you have a non-pure distribution, the extensions can only be created on a +Windows platform, and will be Python version dependent. The installer filename +will reflect this and now has the form :file:`foo-1.0.win32-py2.0.exe`. You +have to create a separate installer for every Python version you want to +support. + +The installer will try to compile pure modules into bytecode after installation +on the target system in normal and optimizing mode. If you don't want this to +happen for some reason, you can run the :command:`bdist_wininst` command with +the :option:`--no-target-compile` and/or the :option:`--no-target-optimize` +option. + +By default the installer will display the cool "Python Powered" logo when it is +run, but you can also supply your own bitmap which must be a Windows +:file:`.bmp` file with the :option:`--bitmap` option. + +The installer will also display a large title on the desktop background window +when it is run, which is constructed from the name of your distribution and the +version number. This can be changed to another text by using the +:option:`--title` option. + +The installer file will be written to the "distribution directory" --- normally +:file:`dist/`, but customizable with the :option:`--dist-dir` option. + + +.. _postinstallation-script: + +The Postinstallation script +--------------------------- + +Starting with Python 2.3, a postinstallation script can be specified which the +:option:`--install-script` option. The basename of the script must be +specified, and the script filename must also be listed in the scripts argument +to the setup function. + +This script will be run at installation time on the target system after all the +files have been copied, with ``argv[1]`` set to :option:`-install`, and again at +uninstallation time before the files are removed with ``argv[1]`` set to +:option:`-remove`. + +The installation script runs embedded in the windows installer, every output +(``sys.stdout``, ``sys.stderr``) is redirected into a buffer and will be +displayed in the GUI after the script has finished. + +Some functions especially useful in this context are available as additional +built-in functions in the installation script. + + +.. function:: directory_created(path) + file_created(path) + + These functions should be called when a directory or file is created by the + postinstall script at installation time. It will register *path* with the + uninstaller, so that it will be removed when the distribution is uninstalled. + To be safe, directories are only removed if they are empty. + + +.. function:: get_special_folder_path(csidl_string) + + This function can be used to retrieve special folder locations on Windows like + the Start Menu or the Desktop. It returns the full path to the folder. + *csidl_string* must be one of the following strings:: + + "CSIDL_APPDATA" + + "CSIDL_COMMON_STARTMENU" + "CSIDL_STARTMENU" + + "CSIDL_COMMON_DESKTOPDIRECTORY" + "CSIDL_DESKTOPDIRECTORY" + + "CSIDL_COMMON_STARTUP" + "CSIDL_STARTUP" + + "CSIDL_COMMON_PROGRAMS" + "CSIDL_PROGRAMS" + + "CSIDL_FONTS" + + If the folder cannot be retrieved, :exc:`OSError` is raised. + + Which folders are available depends on the exact Windows version, and probably + also the configuration. For details refer to Microsoft's documentation of the + :cfunc:`SHGetSpecialFolderPath` function. + + +.. function:: create_shortcut(target, description, filename[, arguments[, workdir[, iconpath[, iconindex]]]]) + + This function creates a shortcut. *target* is the path to the program to be + started by the shortcut. *description* is the description of the shortcut. + *filename* is the title of the shortcut that the user will see. *arguments* + specifies the command line arguments, if any. *workdir* is the working directory + for the program. *iconpath* is the file containing the icon for the shortcut, + and *iconindex* is the index of the icon in the file *iconpath*. Again, for + details consult the Microsoft documentation for the :class:`IShellLink` + interface. + + diff --git a/Doc/distutils/commandref.rst b/Doc/distutils/commandref.rst new file mode 100644 index 0000000..f5f0220 --- /dev/null +++ b/Doc/distutils/commandref.rst @@ -0,0 +1,104 @@ +.. _reference: + +***************** +Command Reference +***************** + +.. % \section{Building modules: the \protect\command{build} command family} +.. % \label{build-cmds} +.. % \subsubsection{\protect\command{build}} +.. % \label{build-cmd} +.. % \subsubsection{\protect\command{build\_py}} +.. % \label{build-py-cmd} +.. % \subsubsection{\protect\command{build\_ext}} +.. % \label{build-ext-cmd} +.. % \subsubsection{\protect\command{build\_clib}} +.. % \label{build-clib-cmd} + + +.. _install-cmd: + +Installing modules: the :command:`install` command family +========================================================= + +The install command ensures that the build commands have been run and then runs +the subcommands :command:`install_lib`, :command:`install_data` and +:command:`install_scripts`. + +.. % \subsubsection{\protect\command{install\_lib}} +.. % \label{install-lib-cmd} + + +.. _install-data-cmd: + +:command:`install_data` +----------------------- + +This command installs all data files provided with the distribution. + + +.. _install-scripts-cmd: + +:command:`install_scripts` +-------------------------- + +This command installs all (Python) scripts in the distribution. + +.. % \subsection{Cleaning up: the \protect\command{clean} command} +.. % \label{clean-cmd} + + +.. _sdist-cmd: + +Creating a source distribution: the :command:`sdist` command +============================================================ + +**\*\*** fragment moved down from above: needs context! **\*\*** + +The manifest template commands are: + ++-------------------------------------------+-----------------------------------------------+ +| Command | Description | ++===========================================+===============================================+ +| :command:`include pat1 pat2 ...` | include all files matching any of the listed | +| | patterns | ++-------------------------------------------+-----------------------------------------------+ +| :command:`exclude pat1 pat2 ...` | exclude all files matching any of the listed | +| | patterns | ++-------------------------------------------+-----------------------------------------------+ +| :command:`recursive-include dir pat1 pat2 | include all files under *dir* matching any of | +| ...` | the listed patterns | ++-------------------------------------------+-----------------------------------------------+ +| :command:`recursive-exclude dir pat1 pat2 | exclude all files under *dir* matching any of | +| ...` | the listed patterns | ++-------------------------------------------+-----------------------------------------------+ +| :command:`global-include pat1 pat2 ...` | include all files anywhere in the source tree | +| | matching --- & any of the listed patterns | ++-------------------------------------------+-----------------------------------------------+ +| :command:`global-exclude pat1 pat2 ...` | exclude all files anywhere in the source tree | +| | matching --- & any of the listed patterns | ++-------------------------------------------+-----------------------------------------------+ +| :command:`prune dir` | exclude all files under *dir* | ++-------------------------------------------+-----------------------------------------------+ +| :command:`graft dir` | include all files under *dir* | ++-------------------------------------------+-----------------------------------------------+ + +The patterns here are Unix-style "glob" patterns: ``*`` matches any sequence of +regular filename characters, ``?`` matches any single regular filename +character, and ``[range]`` matches any of the characters in *range* (e.g., +``a-z``, ``a-zA-Z``, ``a-f0-9_.``). The definition of "regular filename +character" is platform-specific: on Unix it is anything except slash; on Windows +anything except backslash or colon; on Mac OS 9 anything except colon. + +**\*\*** Windows support not there yet **\*\*** + +.. % \section{Creating a built distribution: the +.. % \protect\command{bdist} command family} +.. % \label{bdist-cmds} + +.. % \subsection{\protect\command{bdist}} +.. % \subsection{\protect\command{bdist\_dumb}} +.. % \subsection{\protect\command{bdist\_rpm}} +.. % \subsection{\protect\command{bdist\_wininst}} + + diff --git a/Doc/distutils/configfile.rst b/Doc/distutils/configfile.rst new file mode 100644 index 0000000..0ccd5fd --- /dev/null +++ b/Doc/distutils/configfile.rst @@ -0,0 +1,130 @@ +.. _setup-config: + +************************************ +Writing the Setup Configuration File +************************************ + +Often, it's not possible to write down everything needed to build a distribution +*a priori*: you may need to get some information from the user, or from the +user's system, in order to proceed. As long as that information is fairly +simple---a list of directories to search for C header files or libraries, for +example---then providing a configuration file, :file:`setup.cfg`, for users to +edit is a cheap and easy way to solicit it. Configuration files also let you +provide default values for any command option, which the installer can then +override either on the command-line or by editing the config file. + +The setup configuration file is a useful middle-ground between the setup script +---which, ideally, would be opaque to installers [#]_---and the command-line to +the setup script, which is outside of your control and entirely up to the +installer. In fact, :file:`setup.cfg` (and any other Distutils configuration +files present on the target system) are processed after the contents of the +setup script, but before the command-line. This has several useful +consequences: + +.. % (If you have more advanced needs, such as determining which extensions +.. % to build based on what capabilities are present on the target system, +.. % then you need the Distutils ``auto-configuration'' facility. This +.. % started to appear in Distutils 0.9 but, as of this writing, isn't mature +.. % or stable enough yet for real-world use.) + +* installers can override some of what you put in :file:`setup.py` by editing + :file:`setup.cfg` + +* you can provide non-standard defaults for options that are not easily set in + :file:`setup.py` + +* installers can override anything in :file:`setup.cfg` using the command-line + options to :file:`setup.py` + +The basic syntax of the configuration file is simple:: + + [command] + option=value + ... + +where *command* is one of the Distutils commands (e.g. :command:`build_py`, +:command:`install`), and *option* is one of the options that command supports. +Any number of options can be supplied for each command, and any number of +command sections can be included in the file. Blank lines are ignored, as are +comments, which run from a ``'#'`` character until the end of the line. Long +option values can be split across multiple lines simply by indenting the +continuation lines. + +You can find out the list of options supported by a particular command with the +universal :option:`--help` option, e.g. :: + + > python setup.py --help build_ext + [...] + Options for 'build_ext' command: + --build-lib (-b) directory for compiled extension modules + --build-temp (-t) directory for temporary files (build by-products) + --inplace (-i) ignore build-lib and put compiled extensions into the + source directory alongside your pure Python modules + --include-dirs (-I) list of directories to search for header files + --define (-D) C preprocessor macros to define + --undef (-U) C preprocessor macros to undefine + --swig-opts list of SWIG command line options + [...] + +Note that an option spelled :option:`--foo-bar` on the command-line is spelled +:option:`foo_bar` in configuration files. + +For example, say you want your extensions to be built "in-place"---that is, you +have an extension :mod:`pkg.ext`, and you want the compiled extension file +(:file:`ext.so` on Unix, say) to be put in the same source directory as your +pure Python modules :mod:`pkg.mod1` and :mod:`pkg.mod2`. You can always use the +:option:`--inplace` option on the command-line to ensure this:: + + python setup.py build_ext --inplace + +But this requires that you always specify the :command:`build_ext` command +explicitly, and remember to provide :option:`--inplace`. An easier way is to +"set and forget" this option, by encoding it in :file:`setup.cfg`, the +configuration file for this distribution:: + + [build_ext] + inplace=1 + +This will affect all builds of this module distribution, whether or not you +explicitly specify :command:`build_ext`. If you include :file:`setup.cfg` in +your source distribution, it will also affect end-user builds---which is +probably a bad idea for this option, since always building extensions in-place +would break installation of the module distribution. In certain peculiar cases, +though, modules are built right in their installation directory, so this is +conceivably a useful ability. (Distributing extensions that expect to be built +in their installation directory is almost always a bad idea, though.) + +Another example: certain commands take a lot of options that don't change from +run to run; for example, :command:`bdist_rpm` needs to know everything required +to generate a "spec" file for creating an RPM distribution. Some of this +information comes from the setup script, and some is automatically generated by +the Distutils (such as the list of files installed). But some of it has to be +supplied as options to :command:`bdist_rpm`, which would be very tedious to do +on the command-line for every run. Hence, here is a snippet from the Distutils' +own :file:`setup.cfg`:: + + [bdist_rpm] + release = 1 + packager = Greg Ward + doc_files = CHANGES.txt + README.txt + USAGE.txt + doc/ + examples/ + +Note that the :option:`doc_files` option is simply a whitespace-separated string +split across multiple lines for readability. + + +.. seealso:: + + :ref:`inst-config-syntax` in "Installing Python Modules" + More information on the configuration files is available in the manual for + system administrators. + + +.. rubric:: Footnotes + +.. [#] This ideal probably won't be achieved until auto-configuration is fully + supported by the Distutils. + diff --git a/Doc/distutils/examples.rst b/Doc/distutils/examples.rst new file mode 100644 index 0000000..4e4adc5 --- /dev/null +++ b/Doc/distutils/examples.rst @@ -0,0 +1,241 @@ +.. _examples: + +******** +Examples +******** + +This chapter provides a number of basic examples to help get started with +distutils. Additional information about using distutils can be found in the +Distutils Cookbook. + + +.. seealso:: + + `Distutils Cookbook `_ + Collection of recipes showing how to achieve more control over distutils. + + +.. _pure-mod: + +Pure Python distribution (by module) +==================================== + +If you're just distributing a couple of modules, especially if they don't live +in a particular package, you can specify them individually using the +:option:`py_modules` option in the setup script. + +In the simplest case, you'll have two files to worry about: a setup script and +the single module you're distributing, :file:`foo.py` in this example:: + + / + setup.py + foo.py + +(In all diagrams in this section, ** will refer to the distribution root +directory.) A minimal setup script to describe this situation would be:: + + from distutils.core import setup + setup(name='foo', + version='1.0', + py_modules=['foo'], + ) + +Note that the name of the distribution is specified independently with the +:option:`name` option, and there's no rule that says it has to be the same as +the name of the sole module in the distribution (although that's probably a good +convention to follow). However, the distribution name is used to generate +filenames, so you should stick to letters, digits, underscores, and hyphens. + +Since :option:`py_modules` is a list, you can of course specify multiple +modules, eg. if you're distributing modules :mod:`foo` and :mod:`bar`, your +setup might look like this:: + + / + setup.py + foo.py + bar.py + +and the setup script might be :: + + from distutils.core import setup + setup(name='foobar', + version='1.0', + py_modules=['foo', 'bar'], + ) + +You can put module source files into another directory, but if you have enough +modules to do that, it's probably easier to specify modules by package rather +than listing them individually. + + +.. _pure-pkg: + +Pure Python distribution (by package) +===================================== + +If you have more than a couple of modules to distribute, especially if they are +in multiple packages, it's probably easier to specify whole packages rather than +individual modules. This works even if your modules are not in a package; you +can just tell the Distutils to process modules from the root package, and that +works the same as any other package (except that you don't have to have an +:file:`__init__.py` file). + +The setup script from the last example could also be written as :: + + from distutils.core import setup + setup(name='foobar', + version='1.0', + packages=[''], + ) + +(The empty string stands for the root package.) + +If those two files are moved into a subdirectory, but remain in the root +package, e.g.:: + + / + setup.py + src/ foo.py + bar.py + +then you would still specify the root package, but you have to tell the +Distutils where source files in the root package live:: + + from distutils.core import setup + setup(name='foobar', + version='1.0', + package_dir={'': 'src'}, + packages=[''], + ) + +More typically, though, you will want to distribute multiple modules in the same +package (or in sub-packages). For example, if the :mod:`foo` and :mod:`bar` +modules belong in package :mod:`foobar`, one way to layout your source tree is +:: + + / + setup.py + foobar/ + __init__.py + foo.py + bar.py + +This is in fact the default layout expected by the Distutils, and the one that +requires the least work to describe in your setup script:: + + from distutils.core import setup + setup(name='foobar', + version='1.0', + packages=['foobar'], + ) + +If you want to put modules in directories not named for their package, then you +need to use the :option:`package_dir` option again. For example, if the +:file:`src` directory holds modules in the :mod:`foobar` package:: + + / + setup.py + src/ + __init__.py + foo.py + bar.py + +an appropriate setup script would be :: + + from distutils.core import setup + setup(name='foobar', + version='1.0', + package_dir={'foobar': 'src'}, + packages=['foobar'], + ) + +Or, you might put modules from your main package right in the distribution +root:: + + / + setup.py + __init__.py + foo.py + bar.py + +in which case your setup script would be :: + + from distutils.core import setup + setup(name='foobar', + version='1.0', + package_dir={'foobar': ''}, + packages=['foobar'], + ) + +(The empty string also stands for the current directory.) + +If you have sub-packages, they must be explicitly listed in :option:`packages`, +but any entries in :option:`package_dir` automatically extend to sub-packages. +(In other words, the Distutils does *not* scan your source tree, trying to +figure out which directories correspond to Python packages by looking for +:file:`__init__.py` files.) Thus, if the default layout grows a sub-package:: + + / + setup.py + foobar/ + __init__.py + foo.py + bar.py + subfoo/ + __init__.py + blah.py + +then the corresponding setup script would be :: + + from distutils.core import setup + setup(name='foobar', + version='1.0', + packages=['foobar', 'foobar.subfoo'], + ) + +(Again, the empty string in :option:`package_dir` stands for the current +directory.) + + +.. _single-ext: + +Single extension module +======================= + +Extension modules are specified using the :option:`ext_modules` option. +:option:`package_dir` has no effect on where extension source files are found; +it only affects the source for pure Python modules. The simplest case, a +single extension module in a single C source file, is:: + + / + setup.py + foo.c + +If the :mod:`foo` extension belongs in the root package, the setup script for +this could be :: + + from distutils.core import setup + from distutils.extension import Extension + setup(name='foobar', + version='1.0', + ext_modules=[Extension('foo', ['foo.c'])], + ) + +If the extension actually belongs in a package, say :mod:`foopkg`, then + +With exactly the same source tree layout, this extension can be put in the +:mod:`foopkg` package simply by changing the name of the extension:: + + from distutils.core import setup + from distutils.extension import Extension + setup(name='foobar', + version='1.0', + ext_modules=[Extension('foopkg.foo', ['foo.c'])], + ) + +.. % \section{Multiple extension modules} +.. % \label{multiple-ext} + +.. % \section{Putting it all together} + + diff --git a/Doc/distutils/extending.rst b/Doc/distutils/extending.rst new file mode 100644 index 0000000..a2930c7 --- /dev/null +++ b/Doc/distutils/extending.rst @@ -0,0 +1,96 @@ +.. _extending: + +******************* +Extending Distutils +******************* + +Distutils can be extended in various ways. Most extensions take the form of new +commands or replacements for existing commands. New commands may be written to +support new types of platform-specific packaging, for example, while +replacements for existing commands may be made to modify details of how the +command operates on a package. + +Most extensions of the distutils are made within :file:`setup.py` scripts that +want to modify existing commands; many simply add a few file extensions that +should be copied into packages in addition to :file:`.py` files as a +convenience. + +Most distutils command implementations are subclasses of the :class:`Command` +class from :mod:`distutils.cmd`. New commands may directly inherit from +:class:`Command`, while replacements often derive from :class:`Command` +indirectly, directly subclassing the command they are replacing. Commands are +required to derive from :class:`Command`. + +.. % \section{Extending existing commands} +.. % \label{extend-existing} + +.. % \section{Writing new commands} +.. % \label{new-commands} +.. % \XXX{Would an uninstall command be a good example here?} + + +Integrating new commands +======================== + +There are different ways to integrate new command implementations into +distutils. The most difficult is to lobby for the inclusion of the new features +in distutils itself, and wait for (and require) a version of Python that +provides that support. This is really hard for many reasons. + +The most common, and possibly the most reasonable for most needs, is to include +the new implementations with your :file:`setup.py` script, and cause the +:func:`distutils.core.setup` function use them:: + + from distutils.command.build_py import build_py as _build_py + from distutils.core import setup + + class build_py(_build_py): + """Specialized Python source builder.""" + + # implement whatever needs to be different... + + setup(cmdclass={'build_py': build_py}, + ...) + +This approach is most valuable if the new implementations must be used to use a +particular package, as everyone interested in the package will need to have the +new command implementation. + +Beginning with Python 2.4, a third option is available, intended to allow new +commands to be added which can support existing :file:`setup.py` scripts without +requiring modifications to the Python installation. This is expected to allow +third-party extensions to provide support for additional packaging systems, but +the commands can be used for anything distutils commands can be used for. A new +configuration option, :option:`command_packages` (command-line option +:option:`--command-packages`), can be used to specify additional packages to be +searched for modules implementing commands. Like all distutils options, this +can be specified on the command line or in a configuration file. This option +can only be set in the ``[global]`` section of a configuration file, or before +any commands on the command line. If set in a configuration file, it can be +overridden from the command line; setting it to an empty string on the command +line causes the default to be used. This should never be set in a configuration +file provided with a package. + +This new option can be used to add any number of packages to the list of +packages searched for command implementations; multiple package names should be +separated by commas. When not specified, the search is only performed in the +:mod:`distutils.command` package. When :file:`setup.py` is run with the option +:option:`--command-packages` :option:`distcmds,buildcmds`, however, the packages +:mod:`distutils.command`, :mod:`distcmds`, and :mod:`buildcmds` will be searched +in that order. New commands are expected to be implemented in modules of the +same name as the command by classes sharing the same name. Given the example +command line option above, the command :command:`bdist_openpkg` could be +implemented by the class :class:`distcmds.bdist_openpkg.bdist_openpkg` or +:class:`buildcmds.bdist_openpkg.bdist_openpkg`. + + +Adding new distribution types +============================= + +Commands that create distributions (files in the :file:`dist/` directory) need +to add ``(command, filename)`` pairs to ``self.distribution.dist_files`` so that +:command:`upload` can upload it to PyPI. The *filename* in the pair contains no +path information, only the name of the file itself. In dry-run mode, pairs +should still be added to represent what would have been created. + + diff --git a/Doc/distutils/index.rst b/Doc/distutils/index.rst new file mode 100644 index 0000000..6d82c84 --- /dev/null +++ b/Doc/distutils/index.rst @@ -0,0 +1,30 @@ +.. _distutils-index: + +############################### + Distributing Python Modules +############################### + +:Authors: Greg Ward, Anthony Baxter +:Email: distutils-sig@python.org +:Release: |version| +:Date: |today| + +This document describes the Python Distribution Utilities ("Distutils") from +the module developer's point of view, describing how to use the Distutils to +make Python modules and extensions easily available to a wider audience with +very little overhead for build/release/install mechanics. + +.. toctree:: + :maxdepth: 2 + + introduction.rst + setupscript.rst + configfile.rst + sourcedist.rst + builtdist.rst + packageindex.rst + uploading.rst + examples.rst + extending.rst + commandref.rst + apiref.rst diff --git a/Doc/distutils/introduction.rst b/Doc/distutils/introduction.rst new file mode 100644 index 0000000..b772b01 --- /dev/null +++ b/Doc/distutils/introduction.rst @@ -0,0 +1,208 @@ +.. _distutils-intro: + +**************************** +An Introduction to Distutils +**************************** + +This document covers using the Distutils to distribute your Python modules, +concentrating on the role of developer/distributor: if you're looking for +information on installing Python modules, you should refer to the +:ref:`install-index` chapter. + + +.. _distutils-concepts: + +Concepts & Terminology +====================== + +Using the Distutils is quite simple, both for module developers and for +users/administrators installing third-party modules. As a developer, your +responsibilities (apart from writing solid, well-documented and well-tested +code, of course!) are: + +* write a setup script (:file:`setup.py` by convention) + +* (optional) write a setup configuration file + +* create a source distribution + +* (optional) create one or more built (binary) distributions + +Each of these tasks is covered in this document. + +Not all module developers have access to a multitude of platforms, so it's not +always feasible to expect them to create a multitude of built distributions. It +is hoped that a class of intermediaries, called *packagers*, will arise to +address this need. Packagers will take source distributions released by module +developers, build them on one or more platforms, and release the resulting built +distributions. Thus, users on the most popular platforms will be able to +install most popular Python module distributions in the most natural way for +their platform, without having to run a single setup script or compile a line of +code. + + +.. _distutils-simple-example: + +A Simple Example +================ + +The setup script is usually quite simple, although since it's written in Python, +there are no arbitrary limits to what you can do with it, though you should be +careful about putting arbitrarily expensive operations in your setup script. +Unlike, say, Autoconf-style configure scripts, the setup script may be run +multiple times in the course of building and installing your module +distribution. + +If all you want to do is distribute a module called :mod:`foo`, contained in a +file :file:`foo.py`, then your setup script can be as simple as this:: + + from distutils.core import setup + setup(name='foo', + version='1.0', + py_modules=['foo'], + ) + +Some observations: + +* most information that you supply to the Distutils is supplied as keyword + arguments to the :func:`setup` function + +* those keyword arguments fall into two categories: package metadata (name, + version number) and information about what's in the package (a list of pure + Python modules, in this case) + +* modules are specified by module name, not filename (the same will hold true + for packages and extensions) + +* it's recommended that you supply a little more metadata, in particular your + name, email address and a URL for the project (see section :ref:`setup-script` + for an example) + +To create a source distribution for this module, you would create a setup +script, :file:`setup.py`, containing the above code, and run:: + + python setup.py sdist + +which will create an archive file (e.g., tarball on Unix, ZIP file on Windows) +containing your setup script :file:`setup.py`, and your module :file:`foo.py`. +The archive file will be named :file:`foo-1.0.tar.gz` (or :file:`.zip`), and +will unpack into a directory :file:`foo-1.0`. + +If an end-user wishes to install your :mod:`foo` module, all she has to do is +download :file:`foo-1.0.tar.gz` (or :file:`.zip`), unpack it, and---from the +:file:`foo-1.0` directory---run :: + + python setup.py install + +which will ultimately copy :file:`foo.py` to the appropriate directory for +third-party modules in their Python installation. + +This simple example demonstrates some fundamental concepts of the Distutils. +First, both developers and installers have the same basic user interface, i.e. +the setup script. The difference is which Distutils *commands* they use: the +:command:`sdist` command is almost exclusively for module developers, while +:command:`install` is more often for installers (although most developers will +want to install their own code occasionally). + +If you want to make things really easy for your users, you can create one or +more built distributions for them. For instance, if you are running on a +Windows machine, and want to make things easy for other Windows users, you can +create an executable installer (the most appropriate type of built distribution +for this platform) with the :command:`bdist_wininst` command. For example:: + + python setup.py bdist_wininst + +will create an executable installer, :file:`foo-1.0.win32.exe`, in the current +directory. + +Other useful built distribution formats are RPM, implemented by the +:command:`bdist_rpm` command, Solaris :program:`pkgtool` +(:command:`bdist_pkgtool`), and HP-UX :program:`swinstall` +(:command:`bdist_sdux`). For example, the following command will create an RPM +file called :file:`foo-1.0.noarch.rpm`:: + + python setup.py bdist_rpm + +(The :command:`bdist_rpm` command uses the :command:`rpm` executable, therefore +this has to be run on an RPM-based system such as Red Hat Linux, SuSE Linux, or +Mandrake Linux.) + +You can find out what distribution formats are available at any time by running +:: + + python setup.py bdist --help-formats + + +.. _python-terms: + +General Python terminology +========================== + +If you're reading this document, you probably have a good idea of what modules, +extensions, and so forth are. Nevertheless, just to be sure that everyone is +operating from a common starting point, we offer the following glossary of +common Python terms: + +module + the basic unit of code reusability in Python: a block of code imported by some + other code. Three types of modules concern us here: pure Python modules, + extension modules, and packages. + +pure Python module + a module written in Python and contained in a single :file:`.py` file (and + possibly associated :file:`.pyc` and/or :file:`.pyo` files). Sometimes referred + to as a "pure module." + +extension module + a module written in the low-level language of the Python implementation: C/C++ + for Python, Java for Jython. Typically contained in a single dynamically + loadable pre-compiled file, e.g. a shared object (:file:`.so`) file for Python + extensions on Unix, a DLL (given the :file:`.pyd` extension) for Python + extensions on Windows, or a Java class file for Jython extensions. (Note that + currently, the Distutils only handles C/C++ extensions for Python.) + +package + a module that contains other modules; typically contained in a directory in the + filesystem and distinguished from other directories by the presence of a file + :file:`__init__.py`. + +root package + the root of the hierarchy of packages. (This isn't really a package, since it + doesn't have an :file:`__init__.py` file. But we have to call it something.) + The vast majority of the standard library is in the root package, as are many + small, standalone third-party modules that don't belong to a larger module + collection. Unlike regular packages, modules in the root package can be found in + many directories: in fact, every directory listed in ``sys.path`` contributes + modules to the root package. + + +.. _distutils-term: + +Distutils-specific terminology +============================== + +The following terms apply more specifically to the domain of distributing Python +modules using the Distutils: + +module distribution + a collection of Python modules distributed together as a single downloadable + resource and meant to be installed *en masse*. Examples of some well-known + module distributions are Numeric Python, PyXML, PIL (the Python Imaging + Library), or mxBase. (This would be called a *package*, except that term is + already taken in the Python context: a single module distribution may contain + zero, one, or many Python packages.) + +pure module distribution + a module distribution that contains only pure Python modules and packages. + Sometimes referred to as a "pure distribution." + +non-pure module distribution + a module distribution that contains at least one extension module. Sometimes + referred to as a "non-pure distribution." + +distribution root + the top-level directory of your source tree (or source distribution); the + directory where :file:`setup.py` exists. Generally :file:`setup.py` will be + run from this directory. + + diff --git a/Doc/distutils/packageindex.rst b/Doc/distutils/packageindex.rst new file mode 100644 index 0000000..f0f886b --- /dev/null +++ b/Doc/distutils/packageindex.rst @@ -0,0 +1,65 @@ +.. _package-index: + +********************************** +Registering with the Package Index +********************************** + +The Python Package Index (PyPI) holds meta-data describing distributions +packaged with distutils. The distutils command :command:`register` is used to +submit your distribution's meta-data to the index. It is invoked as follows:: + + python setup.py register + +Distutils will respond with the following prompt:: + + running register + We need to know who you are, so please choose either: + 1. use your existing login, + 2. register as a new user, + 3. have the server generate a new password for you (and email it to you), or + 4. quit + Your selection [default 1]: + +Note: if your username and password are saved locally, you will not see this +menu. + +If you have not registered with PyPI, then you will need to do so now. You +should choose option 2, and enter your details as required. Soon after +submitting your details, you will receive an email which will be used to confirm +your registration. + +Once you are registered, you may choose option 1 from the menu. You will be +prompted for your PyPI username and password, and :command:`register` will then +submit your meta-data to the index. + +You may submit any number of versions of your distribution to the index. If you +alter the meta-data for a particular version, you may submit it again and the +index will be updated. + +PyPI holds a record for each (name, version) combination submitted. The first +user to submit information for a given name is designated the Owner of that +name. They may submit changes through the :command:`register` command or through +the web interface. They may also designate other users as Owners or Maintainers. +Maintainers may edit the package information, but not designate other Owners or +Maintainers. + +By default PyPI will list all versions of a given package. To hide certain +versions, the Hidden property should be set to yes. This must be edited through +the web interface. + + +.. _pypirc: + +The .pypirc file +================ + +The format of the :file:`.pypirc` file is formated as follows:: + + [server-login] + repository: + username: + password: + +*repository* can be ommitted and defaults to ``http://www.python.org/pypi``. + + diff --git a/Doc/distutils/setupscript.rst b/Doc/distutils/setupscript.rst new file mode 100644 index 0000000..26f50e6 --- /dev/null +++ b/Doc/distutils/setupscript.rst @@ -0,0 +1,669 @@ +.. _setup-script: + +************************ +Writing the Setup Script +************************ + +The setup script is the centre of all activity in building, distributing, and +installing modules using the Distutils. The main purpose of the setup script is +to describe your module distribution to the Distutils, so that the various +commands that operate on your modules do the right thing. As we saw in section +:ref:`distutils-simple-example` above, the setup script consists mainly of a call to +:func:`setup`, and most information supplied to the Distutils by the module +developer is supplied as keyword arguments to :func:`setup`. + +Here's a slightly more involved example, which we'll follow for the next couple +of sections: the Distutils' own setup script. (Keep in mind that although the +Distutils are included with Python 1.6 and later, they also have an independent +existence so that Python 1.5.2 users can use them to install other module +distributions. The Distutils' own setup script, shown here, is used to install +the package into Python 1.5.2.) :: + + #!/usr/bin/env python + + from distutils.core import setup + + setup(name='Distutils', + version='1.0', + description='Python Distribution Utilities', + author='Greg Ward', + author_email='gward@python.net', + url='http://www.python.org/sigs/distutils-sig/', + packages=['distutils', 'distutils.command'], + ) + +There are only two differences between this and the trivial one-file +distribution presented in section :ref:`distutils-simple-example`: more metadata, and the +specification of pure Python modules by package, rather than by module. This is +important since the Distutils consist of a couple of dozen modules split into +(so far) two packages; an explicit list of every module would be tedious to +generate and difficult to maintain. For more information on the additional +meta-data, see section :ref:`meta-data`. + +Note that any pathnames (files or directories) supplied in the setup script +should be written using the Unix convention, i.e. slash-separated. The +Distutils will take care of converting this platform-neutral representation into +whatever is appropriate on your current platform before actually using the +pathname. This makes your setup script portable across operating systems, which +of course is one of the major goals of the Distutils. In this spirit, all +pathnames in this document are slash-separated. (Mac OS 9 programmers should +keep in mind that the *absence* of a leading slash indicates a relative path, +the opposite of the Mac OS convention with colons.) + +This, of course, only applies to pathnames given to Distutils functions. If +you, for example, use standard Python functions such as :func:`glob.glob` or +:func:`os.listdir` to specify files, you should be careful to write portable +code instead of hardcoding path separators:: + + glob.glob(os.path.join('mydir', 'subdir', '*.html')) + os.listdir(os.path.join('mydir', 'subdir')) + + +.. _listing-packages: + +Listing whole packages +====================== + +The :option:`packages` option tells the Distutils to process (build, distribute, +install, etc.) all pure Python modules found in each package mentioned in the +:option:`packages` list. In order to do this, of course, there has to be a +correspondence between package names and directories in the filesystem. The +default correspondence is the most obvious one, i.e. package :mod:`distutils` is +found in the directory :file:`distutils` relative to the distribution root. +Thus, when you say ``packages = ['foo']`` in your setup script, you are +promising that the Distutils will find a file :file:`foo/__init__.py` (which +might be spelled differently on your system, but you get the idea) relative to +the directory where your setup script lives. If you break this promise, the +Distutils will issue a warning but still process the broken package anyways. + +If you use a different convention to lay out your source directory, that's no +problem: you just have to supply the :option:`package_dir` option to tell the +Distutils about your convention. For example, say you keep all Python source +under :file:`lib`, so that modules in the "root package" (i.e., not in any +package at all) are in :file:`lib`, modules in the :mod:`foo` package are in +:file:`lib/foo`, and so forth. Then you would put :: + + package_dir = {'': 'lib'} + +in your setup script. The keys to this dictionary are package names, and an +empty package name stands for the root package. The values are directory names +relative to your distribution root. In this case, when you say ``packages = +['foo']``, you are promising that the file :file:`lib/foo/__init__.py` exists. + +Another possible convention is to put the :mod:`foo` package right in +:file:`lib`, the :mod:`foo.bar` package in :file:`lib/bar`, etc. This would be +written in the setup script as :: + + package_dir = {'foo': 'lib'} + +A ``package: dir`` entry in the :option:`package_dir` dictionary implicitly +applies to all packages below *package*, so the :mod:`foo.bar` case is +automatically handled here. In this example, having ``packages = ['foo', +'foo.bar']`` tells the Distutils to look for :file:`lib/__init__.py` and +:file:`lib/bar/__init__.py`. (Keep in mind that although :option:`package_dir` +applies recursively, you must explicitly list all packages in +:option:`packages`: the Distutils will *not* recursively scan your source tree +looking for any directory with an :file:`__init__.py` file.) + + +.. _listing-modules: + +Listing individual modules +========================== + +For a small module distribution, you might prefer to list all modules rather +than listing packages---especially the case of a single module that goes in the +"root package" (i.e., no package at all). This simplest case was shown in +section :ref:`distutils-simple-example`; here is a slightly more involved example:: + + py_modules = ['mod1', 'pkg.mod2'] + +This describes two modules, one of them in the "root" package, the other in the +:mod:`pkg` package. Again, the default package/directory layout implies that +these two modules can be found in :file:`mod1.py` and :file:`pkg/mod2.py`, and +that :file:`pkg/__init__.py` exists as well. And again, you can override the +package/directory correspondence using the :option:`package_dir` option. + + +.. _describing-extensions: + +Describing extension modules +============================ + +Just as writing Python extension modules is a bit more complicated than writing +pure Python modules, describing them to the Distutils is a bit more complicated. +Unlike pure modules, it's not enough just to list modules or packages and expect +the Distutils to go out and find the right files; you have to specify the +extension name, source file(s), and any compile/link requirements (include +directories, libraries to link with, etc.). + +.. % XXX read over this section + +All of this is done through another keyword argument to :func:`setup`, the +:option:`ext_modules` option. :option:`ext_modules` is just a list of +:class:`Extension` instances, each of which describes a single extension module. +Suppose your distribution includes a single extension, called :mod:`foo` and +implemented by :file:`foo.c`. If no additional instructions to the +compiler/linker are needed, describing this extension is quite simple:: + + Extension('foo', ['foo.c']) + +The :class:`Extension` class can be imported from :mod:`distutils.core` along +with :func:`setup`. Thus, the setup script for a module distribution that +contains only this one extension and nothing else might be:: + + from distutils.core import setup, Extension + setup(name='foo', + version='1.0', + ext_modules=[Extension('foo', ['foo.c'])], + ) + +The :class:`Extension` class (actually, the underlying extension-building +machinery implemented by the :command:`build_ext` command) supports a great deal +of flexibility in describing Python extensions, which is explained in the +following sections. + + +Extension names and packages +---------------------------- + +The first argument to the :class:`Extension` constructor is always the name of +the extension, including any package names. For example, :: + + Extension('foo', ['src/foo1.c', 'src/foo2.c']) + +describes an extension that lives in the root package, while :: + + Extension('pkg.foo', ['src/foo1.c', 'src/foo2.c']) + +describes the same extension in the :mod:`pkg` package. The source files and +resulting object code are identical in both cases; the only difference is where +in the filesystem (and therefore where in Python's namespace hierarchy) the +resulting extension lives. + +If you have a number of extensions all in the same package (or all under the +same base package), use the :option:`ext_package` keyword argument to +:func:`setup`. For example, :: + + setup(... + ext_package='pkg', + ext_modules=[Extension('foo', ['foo.c']), + Extension('subpkg.bar', ['bar.c'])], + ) + +will compile :file:`foo.c` to the extension :mod:`pkg.foo`, and :file:`bar.c` to +:mod:`pkg.subpkg.bar`. + + +Extension source files +---------------------- + +The second argument to the :class:`Extension` constructor is a list of source +files. Since the Distutils currently only support C, C++, and Objective-C +extensions, these are normally C/C++/Objective-C source files. (Be sure to use +appropriate extensions to distinguish C++\ source files: :file:`.cc` and +:file:`.cpp` seem to be recognized by both Unix and Windows compilers.) + +However, you can also include SWIG interface (:file:`.i`) files in the list; the +:command:`build_ext` command knows how to deal with SWIG extensions: it will run +SWIG on the interface file and compile the resulting C/C++ file into your +extension. + +**\*\*** SWIG support is rough around the edges and largely untested! **\*\*** + +This warning notwithstanding, options to SWIG can be currently passed like +this:: + + setup(... + ext_modules=[Extension('_foo', ['foo.i'], + swig_opts=['-modern', '-I../include'])], + py_modules=['foo'], + ) + +Or on the commandline like this:: + + > python setup.py build_ext --swig-opts="-modern -I../include" + +On some platforms, you can include non-source files that are processed by the +compiler and included in your extension. Currently, this just means Windows +message text (:file:`.mc`) files and resource definition (:file:`.rc`) files for +Visual C++. These will be compiled to binary resource (:file:`.res`) files and +linked into the executable. + + +Preprocessor options +-------------------- + +Three optional arguments to :class:`Extension` will help if you need to specify +include directories to search or preprocessor macros to define/undefine: +``include_dirs``, ``define_macros``, and ``undef_macros``. + +For example, if your extension requires header files in the :file:`include` +directory under your distribution root, use the ``include_dirs`` option:: + + Extension('foo', ['foo.c'], include_dirs=['include']) + +You can specify absolute directories there; if you know that your extension will +only be built on Unix systems with X11R6 installed to :file:`/usr`, you can get +away with :: + + Extension('foo', ['foo.c'], include_dirs=['/usr/include/X11']) + +You should avoid this sort of non-portable usage if you plan to distribute your +code: it's probably better to write C code like :: + + #include + +If you need to include header files from some other Python extension, you can +take advantage of the fact that header files are installed in a consistent way +by the Distutils :command:`install_header` command. For example, the Numerical +Python header files are installed (on a standard Unix installation) to +:file:`/usr/local/include/python1.5/Numerical`. (The exact location will differ +according to your platform and Python installation.) Since the Python include +directory---\ :file:`/usr/local/include/python1.5` in this case---is always +included in the search path when building Python extensions, the best approach +is to write C code like :: + + #include + +If you must put the :file:`Numerical` include directory right into your header +search path, though, you can find that directory using the Distutils +:mod:`distutils.sysconfig` module:: + + from distutils.sysconfig import get_python_inc + incdir = os.path.join(get_python_inc(plat_specific=1), 'Numerical') + setup(..., + Extension(..., include_dirs=[incdir]), + ) + +Even though this is quite portable---it will work on any Python installation, +regardless of platform---it's probably easier to just write your C code in the +sensible way. + +You can define and undefine pre-processor macros with the ``define_macros`` and +``undef_macros`` options. ``define_macros`` takes a list of ``(name, value)`` +tuples, where ``name`` is the name of the macro to define (a string) and +``value`` is its value: either a string or ``None``. (Defining a macro ``FOO`` +to ``None`` is the equivalent of a bare ``#define FOO`` in your C source: with +most compilers, this sets ``FOO`` to the string ``1``.) ``undef_macros`` is +just a list of macros to undefine. + +For example:: + + Extension(..., + define_macros=[('NDEBUG', '1'), + ('HAVE_STRFTIME', None)], + undef_macros=['HAVE_FOO', 'HAVE_BAR']) + +is the equivalent of having this at the top of every C source file:: + + #define NDEBUG 1 + #define HAVE_STRFTIME + #undef HAVE_FOO + #undef HAVE_BAR + + +Library options +--------------- + +You can also specify the libraries to link against when building your extension, +and the directories to search for those libraries. The ``libraries`` option is +a list of libraries to link against, ``library_dirs`` is a list of directories +to search for libraries at link-time, and ``runtime_library_dirs`` is a list of +directories to search for shared (dynamically loaded) libraries at run-time. + +For example, if you need to link against libraries known to be in the standard +library search path on target systems :: + + Extension(..., + libraries=['gdbm', 'readline']) + +If you need to link with libraries in a non-standard location, you'll have to +include the location in ``library_dirs``:: + + Extension(..., + library_dirs=['/usr/X11R6/lib'], + libraries=['X11', 'Xt']) + +(Again, this sort of non-portable construct should be avoided if you intend to +distribute your code.) + +**\*\*** Should mention clib libraries here or somewhere else! **\*\*** + + +Other options +------------- + +There are still some other options which can be used to handle special cases. + +The :option:`extra_objects` option is a list of object files to be passed to the +linker. These files must not have extensions, as the default extension for the +compiler is used. + +:option:`extra_compile_args` and :option:`extra_link_args` can be used to +specify additional command line options for the respective compiler and linker +command lines. + +:option:`export_symbols` is only useful on Windows. It can contain a list of +symbols (functions or variables) to be exported. This option is not needed when +building compiled extensions: Distutils will automatically add ``initmodule`` +to the list of exported symbols. + + +Relationships between Distributions and Packages +================================================ + +A distribution may relate to packages in three specific ways: + +#. It can require packages or modules. + +#. It can provide packages or modules. + +#. It can obsolete packages or modules. + +These relationships can be specified using keyword arguments to the +:func:`distutils.core.setup` function. + +Dependencies on other Python modules and packages can be specified by supplying +the *requires* keyword argument to :func:`setup`. The value must be a list of +strings. Each string specifies a package that is required, and optionally what +versions are sufficient. + +To specify that any version of a module or package is required, the string +should consist entirely of the module or package name. Examples include +``'mymodule'`` and ``'xml.parsers.expat'``. + +If specific versions are required, a sequence of qualifiers can be supplied in +parentheses. Each qualifier may consist of a comparison operator and a version +number. The accepted comparison operators are:: + + < > == + <= >= != + +These can be combined by using multiple qualifiers separated by commas (and +optional whitespace). In this case, all of the qualifiers must be matched; a +logical AND is used to combine the evaluations. + +Let's look at a bunch of examples: + ++-------------------------+----------------------------------------------+ +| Requires Expression | Explanation | ++=========================+==============================================+ +| ``==1.0`` | Only version ``1.0`` is compatible | ++-------------------------+----------------------------------------------+ +| ``>1.0, !=1.5.1, <2.0`` | Any version after ``1.0`` and before ``2.0`` | +| | is compatible, except ``1.5.1`` | ++-------------------------+----------------------------------------------+ + +Now that we can specify dependencies, we also need to be able to specify what we +provide that other distributions can require. This is done using the *provides* +keyword argument to :func:`setup`. The value for this keyword is a list of +strings, each of which names a Python module or package, and optionally +identifies the version. If the version is not specified, it is assumed to match +that of the distribution. + +Some examples: + ++---------------------+----------------------------------------------+ +| Provides Expression | Explanation | ++=====================+==============================================+ +| ``mypkg`` | Provide ``mypkg``, using the distribution | +| | version | ++---------------------+----------------------------------------------+ +| ``mypkg (1.1)`` | Provide ``mypkg`` version 1.1, regardless of | +| | the distribution version | ++---------------------+----------------------------------------------+ + +A package can declare that it obsoletes other packages using the *obsoletes* +keyword argument. The value for this is similar to that of the *requires* +keyword: a list of strings giving module or package specifiers. Each specifier +consists of a module or package name optionally followed by one or more version +qualifiers. Version qualifiers are given in parentheses after the module or +package name. + +The versions identified by the qualifiers are those that are obsoleted by the +distribution being described. If no qualifiers are given, all versions of the +named module or package are understood to be obsoleted. + + +Installing Scripts +================== + +So far we have been dealing with pure and non-pure Python modules, which are +usually not run by themselves but imported by scripts. + +Scripts are files containing Python source code, intended to be started from the +command line. Scripts don't require Distutils to do anything very complicated. +The only clever feature is that if the first line of the script starts with +``#!`` and contains the word "python", the Distutils will adjust the first line +to refer to the current interpreter location. By default, it is replaced with +the current interpreter location. The :option:`--executable` (or :option:`-e`) +option will allow the interpreter path to be explicitly overridden. + +The :option:`scripts` option simply is a list of files to be handled in this +way. From the PyXML setup script:: + + setup(... + scripts=['scripts/xmlproc_parse', 'scripts/xmlproc_val'] + ) + + +Installing Package Data +======================= + +Often, additional files need to be installed into a package. These files are +often data that's closely related to the package's implementation, or text files +containing documentation that might be of interest to programmers using the +package. These files are called :dfn:`package data`. + +Package data can be added to packages using the ``package_data`` keyword +argument to the :func:`setup` function. The value must be a mapping from +package name to a list of relative path names that should be copied into the +package. The paths are interpreted as relative to the directory containing the +package (information from the ``package_dir`` mapping is used if appropriate); +that is, the files are expected to be part of the package in the source +directories. They may contain glob patterns as well. + +The path names may contain directory portions; any necessary directories will be +created in the installation. + +For example, if a package should contain a subdirectory with several data files, +the files can be arranged like this in the source tree:: + + setup.py + src/ + mypkg/ + __init__.py + module.py + data/ + tables.dat + spoons.dat + forks.dat + +The corresponding call to :func:`setup` might be:: + + setup(..., + packages=['mypkg'], + package_dir={'mypkg': 'src/mypkg'}, + package_data={'mypkg': ['data/*.dat']}, + ) + +.. versionadded:: 2.4 + + +Installing Additional Files +=========================== + +The :option:`data_files` option can be used to specify additional files needed +by the module distribution: configuration files, message catalogs, data files, +anything which doesn't fit in the previous categories. + +:option:`data_files` specifies a sequence of (*directory*, *files*) pairs in the +following way:: + + setup(... + data_files=[('bitmaps', ['bm/b1.gif', 'bm/b2.gif']), + ('config', ['cfg/data.cfg']), + ('/etc/init.d', ['init-script'])] + ) + +Note that you can specify the directory names where the data files will be +installed, but you cannot rename the data files themselves. + +Each (*directory*, *files*) pair in the sequence specifies the installation +directory and the files to install there. If *directory* is a relative path, it +is interpreted relative to the installation prefix (Python's ``sys.prefix`` for +pure-Python packages, ``sys.exec_prefix`` for packages that contain extension +modules). Each file name in *files* is interpreted relative to the +:file:`setup.py` script at the top of the package source distribution. No +directory information from *files* is used to determine the final location of +the installed file; only the name of the file is used. + +You can specify the :option:`data_files` options as a simple sequence of files +without specifying a target directory, but this is not recommended, and the +:command:`install` command will print a warning in this case. To install data +files directly in the target directory, an empty string should be given as the +directory. + + +.. _meta-data: + +Additional meta-data +==================== + +The setup script may include additional meta-data beyond the name and version. +This information includes: + ++----------------------+---------------------------+-----------------+--------+ +| Meta-Data | Description | Value | Notes | ++======================+===========================+=================+========+ +| ``name`` | name of the package | short string | \(1) | ++----------------------+---------------------------+-----------------+--------+ +| ``version`` | version of this release | short string | (1)(2) | ++----------------------+---------------------------+-----------------+--------+ +| ``author`` | package author's name | short string | \(3) | ++----------------------+---------------------------+-----------------+--------+ +| ``author_email`` | email address of the | email address | \(3) | +| | package author | | | ++----------------------+---------------------------+-----------------+--------+ +| ``maintainer`` | package maintainer's name | short string | \(3) | ++----------------------+---------------------------+-----------------+--------+ +| ``maintainer_email`` | email address of the | email address | \(3) | +| | package maintainer | | | ++----------------------+---------------------------+-----------------+--------+ +| ``url`` | home page for the package | URL | \(1) | ++----------------------+---------------------------+-----------------+--------+ +| ``description`` | short, summary | short string | | +| | description of the | | | +| | package | | | ++----------------------+---------------------------+-----------------+--------+ +| ``long_description`` | longer description of the | long string | | +| | package | | | ++----------------------+---------------------------+-----------------+--------+ +| ``download_url`` | location where the | URL | \(4) | +| | package may be downloaded | | | ++----------------------+---------------------------+-----------------+--------+ +| ``classifiers`` | a list of classifiers | list of strings | \(4) | ++----------------------+---------------------------+-----------------+--------+ + +Notes: + +(1) + These fields are required. + +(2) + It is recommended that versions take the form *major.minor[.patch[.sub]]*. + +(3) + Either the author or the maintainer must be identified. + +(4) + These fields should not be used if your package is to be compatible with Python + versions prior to 2.2.3 or 2.3. The list is available from the `PyPI website + `_. + +'short string' + A single line of text, not more than 200 characters. + +'long string' + Multiple lines of plain text in reStructuredText format (see + http://docutils.sf.net/). + +'list of strings' + See below. + +None of the string values may be Unicode. + +Encoding the version information is an art in itself. Python packages generally +adhere to the version format *major.minor[.patch][sub]*. The major number is 0 +for initial, experimental releases of software. It is incremented for releases +that represent major milestones in a package. The minor number is incremented +when important new features are added to the package. The patch number +increments when bug-fix releases are made. Additional trailing version +information is sometimes used to indicate sub-releases. These are +"a1,a2,...,aN" (for alpha releases, where functionality and API may change), +"b1,b2,...,bN" (for beta releases, which only fix bugs) and "pr1,pr2,...,prN" +(for final pre-release release testing). Some examples: + +0.1.0 + the first, experimental release of a package + +1.0.1a2 + the second alpha release of the first patch version of 1.0 + +:option:`classifiers` are specified in a python list:: + + setup(... + classifiers=[ + 'Development Status :: 4 - Beta', + 'Environment :: Console', + 'Environment :: Web Environment', + 'Intended Audience :: End Users/Desktop', + 'Intended Audience :: Developers', + 'Intended Audience :: System Administrators', + 'License :: OSI Approved :: Python Software Foundation License', + 'Operating System :: MacOS :: MacOS X', + 'Operating System :: Microsoft :: Windows', + 'Operating System :: POSIX', + 'Programming Language :: Python', + 'Topic :: Communications :: Email', + 'Topic :: Office/Business', + 'Topic :: Software Development :: Bug Tracking', + ], + ) + +If you wish to include classifiers in your :file:`setup.py` file and also wish +to remain backwards-compatible with Python releases prior to 2.2.3, then you can +include the following code fragment in your :file:`setup.py` before the +:func:`setup` call. :: + + # patch distutils if it can't cope with the "classifiers" or + # "download_url" keywords + from sys import version + if version < '2.2.3': + from distutils.dist import DistributionMetadata + DistributionMetadata.classifiers = None + DistributionMetadata.download_url = None + + +Debugging the setup script +========================== + +Sometimes things go wrong, and the setup script doesn't do what the developer +wants. + +Distutils catches any exceptions when running the setup script, and print a +simple error message before the script is terminated. The motivation for this +behaviour is to not confuse administrators who don't know much about Python and +are trying to install a package. If they get a big long traceback from deep +inside the guts of Distutils, they may think the package or the Python +installation is broken because they don't read all the way down to the bottom +and see that it's a permission problem. + +On the other hand, this doesn't help the developer to find the cause of the +failure. For this purpose, the DISTUTILS_DEBUG environment variable can be set +to anything except an empty string, and distutils will now print detailed +information what it is doing, and prints the full traceback in case an exception +occurs. + + diff --git a/Doc/distutils/sourcedist.rst b/Doc/distutils/sourcedist.rst new file mode 100644 index 0000000..9f15870 --- /dev/null +++ b/Doc/distutils/sourcedist.rst @@ -0,0 +1,207 @@ +.. _source-dist: + +****************************** +Creating a Source Distribution +****************************** + +As shown in section :ref:`distutils-simple-example`, you use the :command:`sdist` command +to create a source distribution. In the simplest case, :: + + python setup.py sdist + +(assuming you haven't specified any :command:`sdist` options in the setup script +or config file), :command:`sdist` creates the archive of the default format for +the current platform. The default format is a gzip'ed tar file +(:file:`.tar.gz`) on Unix, and ZIP file on Windows. + +You can specify as many formats as you like using the :option:`--formats` +option, for example:: + + python setup.py sdist --formats=gztar,zip + +to create a gzipped tarball and a zip file. The available formats are: + ++-----------+-------------------------+---------+ +| Format | Description | Notes | ++===========+=========================+=========+ +| ``zip`` | zip file (:file:`.zip`) | (1),(3) | ++-----------+-------------------------+---------+ +| ``gztar`` | gzip'ed tar file | (2),(4) | +| | (:file:`.tar.gz`) | | ++-----------+-------------------------+---------+ +| ``bztar`` | bzip2'ed tar file | \(4) | +| | (:file:`.tar.bz2`) | | ++-----------+-------------------------+---------+ +| ``ztar`` | compressed tar file | \(4) | +| | (:file:`.tar.Z`) | | ++-----------+-------------------------+---------+ +| ``tar`` | tar file (:file:`.tar`) | \(4) | ++-----------+-------------------------+---------+ + +Notes: + +(1) + default on Windows + +(2) + default on Unix + +(3) + requires either external :program:`zip` utility or :mod:`zipfile` module (part + of the standard Python library since Python 1.6) + +(4) + requires external utilities: :program:`tar` and possibly one of :program:`gzip`, + :program:`bzip2`, or :program:`compress` + + +.. _manifest: + +Specifying the files to distribute +================================== + +If you don't supply an explicit list of files (or instructions on how to +generate one), the :command:`sdist` command puts a minimal default set into the +source distribution: + +* all Python source files implied by the :option:`py_modules` and + :option:`packages` options + +* all C source files mentioned in the :option:`ext_modules` or + :option:`libraries` options ( + + **\*\*** getting C library sources currently broken---no + :meth:`get_source_files` method in :file:`build_clib.py`! **\*\***) + +* scripts identified by the :option:`scripts` option + +* anything that looks like a test script: :file:`test/test\*.py` (currently, the + Distutils don't do anything with test scripts except include them in source + distributions, but in the future there will be a standard for testing Python + module distributions) + +* :file:`README.txt` (or :file:`README`), :file:`setup.py` (or whatever you + called your setup script), and :file:`setup.cfg` + +Sometimes this is enough, but usually you will want to specify additional files +to distribute. The typical way to do this is to write a *manifest template*, +called :file:`MANIFEST.in` by default. The manifest template is just a list of +instructions for how to generate your manifest file, :file:`MANIFEST`, which is +the exact list of files to include in your source distribution. The +:command:`sdist` command processes this template and generates a manifest based +on its instructions and what it finds in the filesystem. + +If you prefer to roll your own manifest file, the format is simple: one filename +per line, regular files (or symlinks to them) only. If you do supply your own +:file:`MANIFEST`, you must specify everything: the default set of files +described above does not apply in this case. + +The manifest template has one command per line, where each command specifies a +set of files to include or exclude from the source distribution. For an +example, again we turn to the Distutils' own manifest template:: + + include *.txt + recursive-include examples *.txt *.py + prune examples/sample?/build + +The meanings should be fairly clear: include all files in the distribution root +matching :file:`\*.txt`, all files anywhere under the :file:`examples` directory +matching :file:`\*.txt` or :file:`\*.py`, and exclude all directories matching +:file:`examples/sample?/build`. All of this is done *after* the standard +include set, so you can exclude files from the standard set with explicit +instructions in the manifest template. (Or, you can use the +:option:`--no-defaults` option to disable the standard set entirely.) There are +several other commands available in the manifest template mini-language; see +section :ref:`sdist-cmd`. + +The order of commands in the manifest template matters: initially, we have the +list of default files as described above, and each command in the template adds +to or removes from that list of files. Once we have fully processed the +manifest template, we remove files that should not be included in the source +distribution: + +* all files in the Distutils "build" tree (default :file:`build/`) + +* all files in directories named :file:`RCS`, :file:`CVS` or :file:`.svn` + +Now we have our complete list of files, which is written to the manifest for +future reference, and then used to build the source distribution archive(s). + +You can disable the default set of included files with the +:option:`--no-defaults` option, and you can disable the standard exclude set +with :option:`--no-prune`. + +Following the Distutils' own manifest template, let's trace how the +:command:`sdist` command builds the list of files to include in the Distutils +source distribution: + +#. include all Python source files in the :file:`distutils` and + :file:`distutils/command` subdirectories (because packages corresponding to + those two directories were mentioned in the :option:`packages` option in the + setup script---see section :ref:`setup-script`) + +#. include :file:`README.txt`, :file:`setup.py`, and :file:`setup.cfg` (standard + files) + +#. include :file:`test/test\*.py` (standard files) + +#. include :file:`\*.txt` in the distribution root (this will find + :file:`README.txt` a second time, but such redundancies are weeded out later) + +#. include anything matching :file:`\*.txt` or :file:`\*.py` in the sub-tree + under :file:`examples`, + +#. exclude all files in the sub-trees starting at directories matching + :file:`examples/sample?/build`\ ---this may exclude files included by the + previous two steps, so it's important that the ``prune`` command in the manifest + template comes after the ``recursive-include`` command + +#. exclude the entire :file:`build` tree, and any :file:`RCS`, :file:`CVS` and + :file:`.svn` directories + +Just like in the setup script, file and directory names in the manifest template +should always be slash-separated; the Distutils will take care of converting +them to the standard representation on your platform. That way, the manifest +template is portable across operating systems. + + +.. _manifest-options: + +Manifest-related options +======================== + +The normal course of operations for the :command:`sdist` command is as follows: + +* if the manifest file, :file:`MANIFEST` doesn't exist, read :file:`MANIFEST.in` + and create the manifest + +* if neither :file:`MANIFEST` nor :file:`MANIFEST.in` exist, create a manifest + with just the default file set + +* if either :file:`MANIFEST.in` or the setup script (:file:`setup.py`) are more + recent than :file:`MANIFEST`, recreate :file:`MANIFEST` by reading + :file:`MANIFEST.in` + +* use the list of files now in :file:`MANIFEST` (either just generated or read + in) to create the source distribution archive(s) + +There are a couple of options that modify this behaviour. First, use the +:option:`--no-defaults` and :option:`--no-prune` to disable the standard +"include" and "exclude" sets. + +Second, you might want to force the manifest to be regenerated---for example, if +you have added or removed files or directories that match an existing pattern in +the manifest template, you should regenerate the manifest:: + + python setup.py sdist --force-manifest + +Or, you might just want to (re)generate the manifest, but not create a source +distribution:: + + python setup.py sdist --manifest-only + +:option:`--manifest-only` implies :option:`--force-manifest`. :option:`-o` is a +shortcut for :option:`--manifest-only`, and :option:`-f` for +:option:`--force-manifest`. + + diff --git a/Doc/distutils/uploading.rst b/Doc/distutils/uploading.rst new file mode 100644 index 0000000..0b82184 --- /dev/null +++ b/Doc/distutils/uploading.rst @@ -0,0 +1,37 @@ +.. _package-upload: + +*************************************** +Uploading Packages to the Package Index +*************************************** + +.. versionadded:: 2.5 + +The Python Package Index (PyPI) not only stores the package info, but also the +package data if the author of the package wishes to. The distutils command +:command:`upload` pushes the distribution files to PyPI. + +The command is invoked immediately after building one or more distribution +files. For example, the command :: + + python setup.py sdist bdist_wininst upload + +will cause the source distribution and the Windows installer to be uploaded to +PyPI. Note that these will be uploaded even if they are built using an earlier +invocation of :file:`setup.py`, but that only distributions named on the command +line for the invocation including the :command:`upload` command are uploaded. + +The :command:`upload` command uses the username, password, and repository URL +from the :file:`$HOME/.pypirc` file (see section :ref:`pypirc` for more on this +file). + +You can use the :option:`--sign` option to tell :command:`upload` to sign each +uploaded file using GPG (GNU Privacy Guard). The :program:`gpg` program must +be available for execution on the system :envvar:`PATH`. You can also specify +which key to use for signing using the :option:`--identity=*name*` option. + +Other :command:`upload` options include :option:`--repository=*url*` (which +lets you override the repository setting from :file:`$HOME/.pypirc`), and +:option:`--show-response` (which displays the full response text from the PyPI +server for help in debugging upload problems). + + diff --git a/Doc/documenting/fromlatex.rst b/Doc/documenting/fromlatex.rst new file mode 100644 index 0000000..67abe8a --- /dev/null +++ b/Doc/documenting/fromlatex.rst @@ -0,0 +1,192 @@ +.. highlightlang:: rest + +Differences to the LaTeX markup +=============================== + +Though the markup language is different, most of the concepts and markup types +of the old LaTeX docs have been kept -- environments as reST directives, inline +commands as reST roles and so forth. + +However, there are some differences in the way these work, partly due to the +differences in the markup languages, partly due to improvements in Sphinx. This +section lists these differences, in order to give those familiar with the old +format a quick overview of what they might run into. + +Inline markup +------------- + +These changes have been made to inline markup: + +* **Cross-reference roles** + + Most of the following semantic roles existed previously as inline commands, + but didn't do anything except formatting the content as code. Now, they + cross-reference to known targets (some names have also been shortened): + + | *mod* (previously *refmodule* or *module*) + | *func* (previously *function*) + | *data* (new) + | *const* + | *class* + | *meth* (previously *method*) + | *attr* (previously *member*) + | *exc* (previously *exception*) + | *cdata* + | *cfunc* (previously *cfunction*) + | *cmacro* (previously *csimplemacro*) + | *ctype* + + Also different is the handling of *func* and *meth*: while previously + parentheses were added to the callable name (like ``\func{str()}``), they are + now appended by the build system -- appending them in the source will result + in double parentheses. This also means that ``:func:`str(object)``` will not + work as expected -- use ````str(object)```` instead! + +* **Inline commands implemented as directives** + + These were inline commands in LaTeX, but are now directives in reST: + + | *deprecated* + | *versionadded* + | *versionchanged* + + These are used like so:: + + .. deprecated:: 2.5 + Reason of deprecation. + + Also, no period is appended to the text for *versionadded* and + *versionchanged*. + + | *note* + | *warning* + + These are used like so:: + + .. note:: + + Content of note. + +* **Otherwise changed commands** + + The *samp* command previously formatted code and added quotation marks around + it. The *samp* role, however, features a new highlighting system just like + *file* does: + + ``:samp:`open({filename}, {mode})``` results in :samp:`open({filename}, {mode})` + +* **Dropped commands** + + These were commands in LaTeX, but are not available as roles: + + | *bfcode* + | *character* (use :samp:`\`\`'c'\`\``) + | *citetitle* (use ```Title `_``) + | *code* (use ````code````) + | *email* (just write the address in body text) + | *filenq* + | *filevar* (use the ``{...}`` highlighting feature of *file*) + | *programopt*, *longprogramopt* (use *option*) + | *ulink* (use ```Title `_``) + | *url* (just write the URL in body text) + | *var* (use ``*var*``) + | *infinity*, *plusminus* (use the Unicode character) + | *shortversion*, *version* (use the ``|version|`` and ``|release|`` substitutions) + | *emph*, *strong* (use the reST markup) + +* **Backslash escaping** + + In reST, a backslash must be escaped in normal text, and in the content of + roles. However, in code literals and literal blocks, it must not be escaped. + Example: ``:file:`C:\\Temp\\my.tmp``` vs. ````open("C:\Temp\my.tmp")````. + + +Information units +----------------- + +Information units (*...desc* environments) have been made reST directives. +These changes to information units should be noted: + +* **New names** + + "desc" has been removed from every name. Additionally, these directives have + new names: + + | *cfunction* (previously *cfuncdesc*) + | *cmacro* (previously *csimplemacrodesc*) + | *exception* (previously *excdesc*) + | *function* (previously *funcdesc*) + | *attribute* (previously *memberdesc*) + + The *classdesc\** and *excclassdesc* environments have been dropped, the + *class* and *exception* directives support classes documented with and without + constructor arguments. + +* **Multiple objects** + + The equivalent of the *...line* commands is:: + + .. function:: do_foo(bar) + do_bar(baz) + + Description of the functions. + + IOW, just give one signatures per line, at the same indentation level. + +* **Arguments** + + There is no *optional* command. Just give function signatures like they + should appear in the output:: + + .. function:: open(filename[, mode[, buffering]]) + + Description. + + Note: markup in the signature is not supported. + +* **Indexing** + + The *...descni* environments have been dropped. To mark an information unit + as unsuitable for index entry generation, use the *noindex* option like so:: + + .. function:: foo_* + :noindex: + + Description. + +* **New information unit** + + There is a new generic information unit called "describe" which can be used + to document things that are not covered by the other units:: + + .. describe:: a == b + + The equals operator. + + +Structure +--------- + +The LaTeX docs were split in several toplevel manuals. Now, all files +are part of the same documentation tree, as indicated by the *toctree* +directives in the sources. Every *toctree* directive embeds other files +as subdocuments of the current file (this structure is not necessarily +mirrored in the filesystem layout). The toplevel file is +:file:`contents.rst`. + +However, most of the old directory structure has been kept, with the +directories renamed as follows: + +* :file:`api` -> :file:`c-api` +* :file:`dist` -> :file:`distutils`, with the single TeX file split up +* :file:`doc` -> :file:`documenting` +* :file:`ext` -> :file:`extending` +* :file:`inst` -> :file:`installing` +* :file:`lib` -> :file:`library` +* :file:`mac` -> merged into :file:`library`, with `mac/using.tex` + moved to `howto/pythonmac.rst` +* :file:`ref` -> :file:`reference` +* :file:`tut` -> :file:`tutorial`, with the single TeX file split up + + +.. XXX more (index-generating, production lists, ...) diff --git a/Doc/documenting/index.rst b/Doc/documenting/index.rst new file mode 100644 index 0000000..1a3778b --- /dev/null +++ b/Doc/documenting/index.rst @@ -0,0 +1,33 @@ +.. _documenting-index: + +###################### + Documenting Python +###################### + + +The Python language has a substantial body of documentation, much of it +contributed by various authors. The markup used for the Python documentation is +`reStructuredText`_, developed by the `docutils`_ project, amended by custom +directives and using a toolset named *Sphinx* to postprocess the HTML output. + +This document describes the style guide for our documentation, the custom +reStructuredText markup introduced to support Python documentation and how it +should be used, as well as the Sphinx build system. + +.. _reStructuredText: http://docutils.sf.net/rst.html +.. _docutils: http://docutils.sf.net/ + +If you're interested in contributing to Python's documentation, there's no need +to write reStructuredText if you're not so inclined; plain text contributions +are more than welcome as well. + +.. toctree:: + + intro.rst + style.rst + rest.rst + markup.rst + sphinx.rst + +.. XXX add credits, thanks etc. + diff --git a/Doc/documenting/intro.rst b/Doc/documenting/intro.rst new file mode 100644 index 0000000..e02ad7d --- /dev/null +++ b/Doc/documenting/intro.rst @@ -0,0 +1,29 @@ +Introduction +============ + +Python's documentation has long been considered to be good for a free +programming language. There are a number of reasons for this, the most +important being the early commitment of Python's creator, Guido van Rossum, to +providing documentation on the language and its libraries, and the continuing +involvement of the user community in providing assistance for creating and +maintaining documentation. + +The involvement of the community takes many forms, from authoring to bug reports +to just plain complaining when the documentation could be more complete or +easier to use. + +This document is aimed at authors and potential authors of documentation for +Python. More specifically, it is for people contributing to the standard +documentation and developing additional documents using the same tools as the +standard documents. This guide will be less useful for authors using the Python +documentation tools for topics other than Python, and less useful still for +authors not using the tools at all. + +If your interest is in contributing to the Python documentation, but you don't +have the time or inclination to learn reStructuredText and the markup structures +documented here, there's a welcoming place for you among the Python contributors +as well. Any time you feel that you can clarify existing documentation or +provide documentation that's missing, the existing documentation team will +gladly work with you to integrate your text, dealing with the markup for you. +Please don't let the material in this document stand between the documentation +and your desire to help out! \ No newline at end of file diff --git a/Doc/documenting/markup.rst b/Doc/documenting/markup.rst new file mode 100644 index 0000000..831fad9 --- /dev/null +++ b/Doc/documenting/markup.rst @@ -0,0 +1,775 @@ +.. highlightlang:: rest + +Additional Markup Constructs +============================ + +Sphinx adds a lot of new directives and interpreted text roles to standard reST +markup. This section contains the reference material for these facilities. +Documentation for "standard" reST constructs is not included here, though +they are used in the Python documentation. + +File-wide metadata +------------------ + +reST has the concept of "field lists"; these are a sequence of fields marked up +like this:: + + :Field name: Field content + +A field list at the very top of a file is parsed as the "docinfo", which in +normal documents can be used to record the author, date of publication and +other metadata. In Sphinx, the docinfo is used as metadata, too, but not +displayed in the output. + +At the moment, only one metadata field is recognized: + +``nocomments`` + If set, the web application won't display a comment form for a page generated + from this source file. + + +Meta-information markup +----------------------- + +.. describe:: sectionauthor + + Identifies the author of the current section. The argument should include + the author's name such that it can be used for presentation (though it isn't) + and email address. The domain name portion of the address should be lower + case. Example:: + + .. sectionauthor:: Guido van Rossum + + Currently, this markup isn't reflected in the output in any way, but it helps + keep track of contributions. + + +Module-specific markup +---------------------- + +The markup described in this section is used to provide information about a +module being documented. Each module should be documented in its own file. +Normally this markup appears after the title heading of that file; a typical +file might start like this:: + + :mod:`parrot` -- Dead parrot access + =================================== + + .. module:: parrot + :platform: Unix, Windows + :synopsis: Analyze and reanimate dead parrots. + .. moduleauthor:: Eric Cleese + .. moduleauthor:: John Idle + +As you can see, the module-specific markup consists of two directives, the +``module`` directive and the ``moduleauthor`` directive. + +.. describe:: module + + This directive marks the beginning of the description of a module (or package + submodule, in which case the name should be fully qualified, including the + package name). + + The ``platform`` option, if present, is a comma-separated list of the + platforms on which the module is available (if it is available on all + platforms, the option should be omitted). The keys are short identifiers; + examples that are in use include "IRIX", "Mac", "Windows", and "Unix". It is + important to use a key which has already been used when applicable. + + The ``synopsis`` option should consist of one sentence describing the + module's purpose -- it is currently only used in the Global Module Index. + +.. describe:: moduleauthor + + The ``moduleauthor`` directive, which can appear multiple times, names the + authors of the module code, just like ``sectionauthor`` names the author(s) + of a piece of documentation. It too does not result in any output currently. + + +.. note:: + + It is important to make the section title of a module-describing file + meaningful since that value will be inserted in the table-of-contents trees + in overview files. + + +Information units +----------------- + +There are a number of directives used to describe specific features provided by +modules. Each directive requires one or more signatures to provide basic +information about what is being described, and the content should be the +description. The basic version makes entries in the general index; if no index +entry is desired, you can give the directive option flag ``:noindex:``. The +following example shows all of the features of this directive type:: + + .. function:: spam(eggs) + ham(eggs) + :noindex: + + Spam or ham the foo. + +The signatures of object methods or data attributes should always include the +type name (``.. method:: FileInput.input(...)``), even if it is obvious from the +context which type they belong to; this is to enable consistent +cross-references. If you describe methods belonging to an abstract protocol, +such as "context managers", include a (pseudo-)type name too to make the +index entries more informative. + +The directives are: + +.. describe:: cfunction + + Describes a C function. The signature should be given as in C, e.g.:: + + .. cfunction:: PyObject* PyType_GenericAlloc(PyTypeObject *type, Py_ssize_t nitems) + + This is also used to describe function-like preprocessor macros. The names + of the arguments should be given so they may be used in the description. + + Note that you don't have to backslash-escape asterisks in the signature, + as it is not parsed by the reST inliner. + +.. describe:: cmember + + Describes a C struct member. Example signature:: + + .. cmember:: PyObject* PyTypeObject.tp_bases + + The text of the description should include the range of values allowed, how + the value should be interpreted, and whether the value can be changed. + References to structure members in text should use the ``member`` role. + +.. describe:: cmacro + + Describes a "simple" C macro. Simple macros are macros which are used + for code expansion, but which do not take arguments so cannot be described as + functions. This is not to be used for simple constant definitions. Examples + of its use in the Python documentation include :cmacro:`PyObject_HEAD` and + :cmacro:`Py_BEGIN_ALLOW_THREADS`. + +.. describe:: ctype + + Describes a C type. The signature should just be the type name. + +.. describe:: cvar + + Describes a global C variable. The signature should include the type, such + as:: + + .. cvar:: PyObject* PyClass_Type + +.. describe:: data + + Describes global data in a module, including both variables and values used + as "defined constants." Class and object attributes are not documented + using this environment. + +.. describe:: exception + + Describes an exception class. The signature can, but need not include + parentheses with constructor arguments. + +.. describe:: function + + Describes a module-level function. The signature should include the + parameters, enclosing optional parameters in brackets. Default values can be + given if it enhances clarity. For example:: + + .. function:: Timer.repeat([repeat=3[, number=1000000]]) + + Object methods are not documented using this directive. Bound object methods + placed in the module namespace as part of the public interface of the module + are documented using this, as they are equivalent to normal functions for + most purposes. + + The description should include information about the parameters required and + how they are used (especially whether mutable objects passed as parameters + are modified), side effects, and possible exceptions. A small example may be + provided. + +.. describe:: class + + Describes a class. The signature can include parentheses with parameters + which will be shown as the constructor arguments. + +.. describe:: attribute + + Describes an object data attribute. The description should include + information about the type of the data to be expected and whether it may be + changed directly. + +.. describe:: method + + Describes an object method. The parameters should not include the ``self`` + parameter. The description should include similar information to that + described for ``function``. + +.. describe:: opcode + + Describes a Python bytecode instruction. + + +There is also a generic version of these directives: + +.. describe:: describe + + This directive produces the same formatting as the specific ones explained + above but does not create index entries or cross-referencing targets. It is + used, for example, to describe the directives in this document. Example:: + + .. describe:: opcode + + Describes a Python bytecode instruction. + + +Showing code examples +--------------------- + +Examples of Python source code or interactive sessions are represented using +standard reST literal blocks. They are started by a ``::`` at the end of the +preceding paragraph and delimited by indentation. + +Representing an interactive session requires including the prompts and output +along with the Python code. No special markup is required for interactive +sessions. After the last line of input or output presented, there should not be +an "unused" primary prompt; this is an example of what *not* to do:: + + >>> 1 + 1 + 2 + >>> + +Syntax highlighting is handled in a smart way: + +* There is a "highlighting language" for each source file. Per default, + this is ``'python'`` as the majority of files will have to highlight Python + snippets. + +* Within Python highlighting mode, interactive sessions are recognized + automatically and highlighted appropriately. + +* The highlighting language can be changed using the ``highlightlang`` + directive, used as follows:: + + .. highlightlang:: c + + This language is used until the next ``highlightlang`` directive is + encountered. + +* The valid values for the highlighting language are: + + * ``python`` (the default) + * ``c`` + * ``rest`` + * ``none`` (no highlighting) + +* If highlighting with the current language fails, the block is not highlighted + in any way. + +Longer displays of verbatim text may be included by storing the example text in +an external file containing only plain text. The file may be included using the +``literalinclude`` directive. [1]_ For example, to include the Python source file +:file:`example.py`, use:: + + .. literalinclude:: example.py + +The file name is relative to the current file's path. Documentation-specific +include files should be placed in the ``Doc/includes`` subdirectory. + + +Inline markup +------------- + +As said before, Sphinx uses interpreted text roles to insert semantic markup in +documents. + +Variable names are an exception, they should be marked simply with ``*var*``. + +For all other roles, you have to write ``:rolename:`content```. + +The following roles refer to objects in modules and are possibly hyperlinked if +a matching identifier is found: + +.. describe:: mod + + The name of a module; a dotted name may be used. This should also be used for + package names. + +.. describe:: func + + The name of a Python function; dotted names may be used. The role text + should include trailing parentheses to enhance readability. The parentheses + are stripped when searching for identifiers. + +.. describe:: data + + The name of a module-level variable. + +.. describe:: const + + The name of a "defined" constant. This may be a C-language ``#define`` + or a Python variable that is not intended to be changed. + +.. describe:: class + + A class name; a dotted name may be used. + +.. describe:: meth + + The name of a method of an object. The role text should include the type + name, method name and the trailing parentheses. A dotted name may be used. + +.. describe:: attr + + The name of a data attribute of an object. + +.. describe:: exc + + The name of an exception. A dotted name may be used. + +The name enclosed in this markup can include a module name and/or a class name. +For example, ``:func:`filter``` could refer to a function named ``filter`` in +the current module, or the built-in function of that name. In contrast, +``:func:`foo.filter``` clearly refers to the ``filter`` function in the ``foo`` +module. + +A similar heuristic is used to determine whether the name is an attribute of +the currently documented class. + +The following roles create cross-references to C-language constructs if they +are defined in the API documentation: + +.. describe:: cdata + + The name of a C-language variable. + +.. describe:: cfunc + + The name of a C-language function. Should include trailing parentheses. + +.. describe:: cmacro + + The name of a "simple" C macro, as defined above. + +.. describe:: ctype + + The name of a C-language type. + + +The following role does possibly create a cross-reference, but does not refer +to objects: + +.. describe:: token + + The name of a grammar token (used in the reference manual to create links + between production displays). + +--------- + +The following roles don't do anything special except formatting the text +in a different style: + +.. describe:: command + + The name of an OS-level command, such as ``rm``. + +.. describe:: dfn + + Mark the defining instance of a term in the text. (No index entries are + generated.) + +.. describe:: envvar + + An environment variable. Index entries are generated. + +.. describe:: file + + The name of a file or directory. Within the contents, you can use curly + braces to indicate a "variable" part, for example:: + + ... is installed in :file:`/usr/lib/python2.{x}/site-packages` ... + + In the built documentation, the ``x`` will be displayed differently to + indicate that it is to be replaced by the Python minor version. + +.. describe:: guilabel + + Labels presented as part of an interactive user interface should be marked + using ``guilabel``. This includes labels from text-based interfaces such as + those created using :mod:`curses` or other text-based libraries. Any label + used in the interface should be marked with this role, including button + labels, window titles, field names, menu and menu selection names, and even + values in selection lists. + +.. describe:: kbd + + Mark a sequence of keystrokes. What form the key sequence takes may depend + on platform- or application-specific conventions. When there are no relevant + conventions, the names of modifier keys should be spelled out, to improve + accessibility for new users and non-native speakers. For example, an + *xemacs* key sequence may be marked like ``:kbd:`C-x C-f```, but without + reference to a specific application or platform, the same sequence should be + marked as ``:kbd:`Control-x Control-f```. + +.. describe:: keyword + + The name of a keyword in a programming language. + +.. describe:: mailheader + + The name of an RFC 822-style mail header. This markup does not imply that + the header is being used in an email message, but can be used to refer to any + header of the same "style." This is also used for headers defined by the + various MIME specifications. The header name should be entered in the same + way it would normally be found in practice, with the camel-casing conventions + being preferred where there is more than one common usage. For example: + ``:mailheader:`Content-Type```. + +.. describe:: makevar + + The name of a :command:`make` variable. + +.. describe:: manpage + + A reference to a Unix manual page including the section, + e.g. ``:manpage:`ls(1)```. + +.. describe:: menuselection + + Menu selections should be marked using the ``menuselection`` role. This is + used to mark a complete sequence of menu selections, including selecting + submenus and choosing a specific operation, or any subsequence of such a + sequence. The names of individual selections should be separated by + ``-->``. + + For example, to mark the selection "Start > Programs", use this markup:: + + :menuselection:`Start --> Programs` + + When including a selection that includes some trailing indicator, such as the + ellipsis some operating systems use to indicate that the command opens a + dialog, the indicator should be omitted from the selection name. + +.. describe:: mimetype + + The name of a MIME type, or a component of a MIME type (the major or minor + portion, taken alone). + +.. describe:: newsgroup + + The name of a Usenet newsgroup. + +.. describe:: option + + A command-line option to an executable program. The leading hyphen(s) must + be included. + +.. describe:: program + + The name of an executable program. This may differ from the file name for + the executable for some platforms. In particular, the ``.exe`` (or other) + extension should be omitted for Windows programs. + +.. describe:: regexp + + A regular expression. Quotes should not be included. + +.. describe:: samp + + A piece of literal text, such as code. Within the contents, you can use + curly braces to indicate a "variable" part, as in ``:file:``. + + If you don't need the "variable part" indication, use the standard + ````code```` instead. + +.. describe:: var + + A Python or C variable or parameter name. + + +The following roles generate external links: + +.. describe:: pep + + A reference to a Python Enhancement Proposal. This generates appropriate + index entries. The text "PEP *number*\ " is generated; in the HTML output, + this text is a hyperlink to an online copy of the specified PEP. + +.. describe:: rfc + + A reference to an Internet Request for Comments. This generates appropriate + index entries. The text "RFC *number*\ " is generated; in the HTML output, + this text is a hyperlink to an online copy of the specified RFC. + + +Note that there are no special roles for including hyperlinks as you can use +the standard reST markup for that purpose. + + +.. _doc-ref-role: + +Cross-linking markup +-------------------- + +To support cross-referencing to arbitrary sections in the documentation, the +standard reST labels are "abused" a bit: Every label must precede a section +title; and every label name must be unique throughout the entire documentation +source. + +You can then reference to these sections using the ``:ref:`label-name``` role. + +Example:: + + .. _my-reference-label: + + Section to cross-reference + -------------------------- + + This is the text of the section. + + It refers to the section itself, see :ref:`my-reference-label`. + +The ``:ref:`` invocation is replaced with the section title. + + +Paragraph-level markup +---------------------- + +These directives create short paragraphs and can be used inside information +units as well as normal text: + +.. describe:: note + + An especially important bit of information about an API that a user should be + aware of when using whatever bit of API the note pertains to. The content of + the directive should be written in complete sentences and include all + appropriate punctuation. + + Example:: + + .. note:: + + This function is not suitable for sending spam e-mails. + +.. describe:: warning + + An important bit of information about an API that a user should be very aware + of when using whatever bit of API the warning pertains to. The content of + the directive should be written in complete sentences and include all + appropriate punctuation. This differs from ``note`` in that it is recommended + over ``note`` for information regarding security. + +.. describe:: versionadded + + This directive documents the version of Python which added the described + feature to the library or C API. When this applies to an entire module, it + should be placed at the top of the module section before any prose. + + The first argument must be given and is the version in question; you can add + a second argument consisting of a *brief* explanation of the change. + + Example:: + + .. versionadded:: 2.5 + The `spam` parameter. + + Note that there must be no blank line between the directive head and the + explanation; this is to make these blocks visually continuous in the markup. + +.. describe:: versionchanged + + Similar to ``versionadded``, but describes when and what changed in the named + feature in some way (new parameters, changed side effects, etc.). + +-------------- + +.. describe:: seealso + + Many sections include a list of references to module documentation or + external documents. These lists are created using the ``seealso`` directive. + + The ``seealso`` directive is typically placed in a section just before any + sub-sections. For the HTML output, it is shown boxed off from the main flow + of the text. + + The content of the ``seealso`` directive should be a reST definition list. + Example:: + + .. seealso:: + + Module :mod:`zipfile` + Documentation of the :mod:`zipfile` standard module. + + `GNU tar manual, Basic Tar Format `_ + Documentation for tar archive files, including GNU tar extensions. + +.. describe:: rubric + + This directive creates a paragraph heading that is not used to create a + table of contents node. It is currently used for the "Footnotes" caption. + +.. describe:: centered + + This directive creates a centered boldfaced paragraph. Use it as follows:: + + .. centered:: + + Paragraph contents. + + +Table-of-contents markup +------------------------ + +Since reST does not have facilities to interconnect several documents, or split +documents into multiple output files, Sphinx uses a custom directive to add +relations between the single files the documentation is made of, as well as +tables of contents. The ``toctree`` directive is the central element. + +.. describe:: toctree + + This directive inserts a "TOC tree" at the current location, using the + individual TOCs (including "sub-TOC trees") of the files given in the + directive body. A numeric ``maxdepth`` option may be given to indicate the + depth of the tree; by default, all levels are included. + + Consider this example (taken from the library reference index):: + + .. toctree:: + :maxdepth: 2 + + intro.rst + strings.rst + datatypes.rst + numeric.rst + (many more files listed here) + + This accomplishes two things: + + * Tables of contents from all those files are inserted, with a maximum depth + of two, that means one nested heading. ``toctree`` directives in those + files are also taken into account. + * Sphinx knows that the relative order of the files ``intro.rst``, + ``strings.rst`` and so forth, and it knows that they are children of the + shown file, the library index. From this information it generates "next + chapter", "previous chapter" and "parent chapter" links. + + In the end, all files included in the build process must occur in one + ``toctree`` directive; Sphinx will emit a warning if it finds a file that is + not included, because that means that this file will not be reachable through + standard navigation. + + The special file ``contents.rst`` at the root of the source directory is the + "root" of the TOC tree hierarchy; from it the "Contents" page is generated. + + +Index-generating markup +----------------------- + +Sphinx automatically creates index entries from all information units (like +functions, classes or attributes) like discussed before. + +However, there is also an explicit directive available, to make the index more +comprehensive and enable index entries in documents where information is not +mainly contained in information units, such as the language reference. + +The directive is ``index`` and contains one or more index entries. Each entry +consists of a type and a value, separated by a colon. + +For example:: + + .. index:: + single: execution!context + module: __main__ + module: sys + triple: module; search; path + +This directive contains five entries, which will be converted to entries in the +generated index which link to the exact location of the index statement (or, in +case of offline media, the corresponding page number). + +The possible entry types are: + +single + Creates a single index entry. Can be made a subentry by separating the + subentry text with a semicolon (this is also used below to describe what + entries are created). +pair + ``pair: loop; statement`` is a shortcut that creates two index entries, + namely ``loop; statement`` and ``statement; loop``. +triple + Likewise, ``triple: module; search; path`` is a shortcut that creates three + index entries, which are ``module; search path``, ``search; path, module`` and + ``path; module search``. +module, keyword, operator, object, exception, statement, builtin + These all create two index entries. For example, ``module: hashlib`` creates + the entries ``module; hashlib`` and ``hashlib; module``. + + +Grammar production displays +--------------------------- + +Special markup is available for displaying the productions of a formal grammar. +The markup is simple and does not attempt to model all aspects of BNF (or any +derived forms), but provides enough to allow context-free grammars to be +displayed in a way that causes uses of a symbol to be rendered as hyperlinks to +the definition of the symbol. There is this directive: + +.. describe:: productionlist + + This directive is used to enclose a group of productions. Each production is + given on a single line and consists of a name, separated by a colon from the + following definition. If the definition spans multiple lines, each + continuation line must begin with a colon placed at the same column as in the + first line. + + Blank lines are not allowed within ``productionlist`` directive arguments. + + The definition can contain token names which are marked as interpreted text + (e.g. ``sum ::= `integer` "+" `integer```) -- this generates cross-references + to the productions of these tokens. + + Note that no further reST parsing is done in the production, so that you + don't have to escape ``*`` or ``|`` characters. + + +.. XXX describe optional first parameter + +The following is an example taken from the Python Reference Manual:: + + .. productionlist:: + try_stmt: try1_stmt | try2_stmt + try1_stmt: "try" ":" `suite` + : ("except" [`expression` ["," `target`]] ":" `suite`)+ + : ["else" ":" `suite`] + : ["finally" ":" `suite`] + try2_stmt: "try" ":" `suite` + : "finally" ":" `suite` + + +Substitutions +------------- + +The documentation system provides three substitutions that are defined by default. +They are set in the build configuration file, see :ref:`doc-build-config`. + +.. describe:: |release| + + Replaced by the Python release the documentation refers to. This is the full + version string including alpha/beta/release candidate tags, e.g. ``2.5.2b3``. + +.. describe:: |version| + + Replaced by the Python version the documentation refers to. This consists + only of the major and minor version parts, e.g. ``2.5``, even for version + 2.5.1. + +.. describe:: |today| + + Replaced by either today's date, or the date set in the build configuration + file. Normally has the format ``April 14, 2007``. + + +.. rubric:: Footnotes + +.. [1] There is a standard ``.. include`` directive, but it raises errors if the + file is not found. This one only emits a warning. diff --git a/Doc/documenting/rest.rst b/Doc/documenting/rest.rst new file mode 100644 index 0000000..8a4fc3d --- /dev/null +++ b/Doc/documenting/rest.rst @@ -0,0 +1,251 @@ +.. highlightlang:: rest + +reStructuredText Primer +======================= + +This section is a brief introduction to reStructuredText (reST) concepts and +syntax, intended to provide authors with enough information to author documents +productively. Since reST was designed to be a simple, unobtrusive markup +language, this will not take too long. + +.. seealso:: + + The authoritative `reStructuredText User + Documentation `_. + + +Paragraphs +---------- + +The paragraph is the most basic block in a reST document. Paragraphs are simply +chunks of text separated by one or more blank lines. As in Python, indentation +is significant in reST, so all lines of the same paragraph must be left-aligned +to the same level of indentation. + + +Inline markup +------------- + +The standard reST inline markup is quite simple: use + +* one asterisk: ``*text*`` for emphasis (italics), +* two asterisks: ``**text**`` for strong emphasis (boldface), and +* backquotes: ````text```` for code samples. + +If asterisks or backquotes appear in running text and could be confused with +inline markup delimiters, they have to be escaped with a backslash. + +Be aware of some restrictions of this markup: + +* it may not be nested, +* content may not start or end with whitespace: ``* text*`` is wrong, +* it must be separated from surrounding text by non-word characters. Use a + backslash escaped space to work around that: ``thisis\ *one*\ word``. + +These restrictions may be lifted in future versions of the docutils. + +reST also allows for custom "interpreted text roles"', which signify that the +enclosed text should be interpreted in a specific way. Sphinx uses this to +provide semantic markup and cross-referencing of identifiers, as described in +the appropriate section. The general syntax is ``:rolename:`content```. + + +Lists and Quotes +---------------- + +List markup is natural: just place an asterisk at the start of a paragraph and +indent properly. The same goes for numbered lists; they can also be +autonumbered using a ``#`` sign:: + + * This is a bulleted list. + * It has two items, the second + item uses two lines. + + 1. This is a numbered list. + 2. It has two items too. + + #. This is a numbered list. + #. It has two items too. + +Note that Sphinx disables the use of enumerated lists introduced by alphabetic +or roman numerals, such as :: + + A. First item + B. Second item + + +Nested lists are possible, but be aware that they must be separated from the +parent list items by blank lines:: + + * this is + * a list + + * with a nested list + * and some subitems + + * and here the parent list continues + +Definition lists are created as follows:: + + term (up to a line of text) + Definition of the term, which must be indented + + and can even consist of multiple paragraphs + + next term + Description. + + +Paragraphs are quoted by just indenting them more than the surrounding +paragraphs. + + +Source Code +----------- + +Literal code blocks are introduced by ending a paragraph with the special marker +``::``. The literal block must be indented, to be able to include blank lines:: + + This is a normal text paragraph. The next paragraph is a code sample:: + + It is not processed in any way, except + that the indentation is removed. + + It can span multiple lines. + + This is a normal text paragraph again. + +The handling of the ``::`` marker is smart: + +* If it occurs as a paragraph of its own, that paragraph is completely left + out of the document. +* If it is preceded by whitespace, the marker is removed. +* If it is preceded by non-whitespace, the marker is replaced by a single + colon. + +That way, the second sentence in the above example's first paragraph would be +rendered as "The next paragraph is a code sample:". + + +Hyperlinks +---------- + +External links +^^^^^^^^^^^^^^ + +Use ```Link text `_`` for inline web links. If the link text +should be the web address, you don't need special markup at all, the parser +finds links and mail addresses in ordinary text. + +Internal links +^^^^^^^^^^^^^^ + +Internal linking is done via a special reST role, see the section on specific +markup, :ref:`doc-ref-role`. + + +Sections +-------- + +Section headers are created by underlining (and optionally overlining) the +section title with a punctuation character, at least as long as the text:: + + ================= + This is a heading + ================= + +Normally, there are no heading levels assigned to certain characters as the +structure is determined from the succession of headings. However, for the +Python documentation, we use this convention: + +* ``#`` with overline, for parts +* ``*`` with overline, for chapters +* ``=``, for sections +* ``-``, for subsections +* ``^``, for subsubsections +* ``"``, for paragraphs + + +Explicit Markup +--------------- + +"Explicit markup" is used in reST for most constructs that need special +handling, such as footnotes, specially-highlighted paragraphs, comments, and +generic directives. + +An explicit markup block begins with a line starting with ``..`` followed by +whitespace and is terminated by the next paragraph at the same level of +indentation. (There needs to be a blank line between explicit markup and normal +paragraphs. This may all sound a bit complicated, but it is intuitive enough +when you write it.) + + +Directives +---------- + +A directive is a generic block of explicit markup. Besides roles, it is one of +the extension mechanisms of reST, and Sphinx makes heavy use of it. + +Basically, a directive consists of a name, arguments, options and content. (Keep +this terminology in mind, it is used in the next chapter describing custom +directives.) Looking at this example, :: + + .. function:: foo(x) + foo(y, z) + :bar: no + + Return a line of text input from the user. + +``function`` is the directive name. It is given two arguments here, the +remainder of the first line and the second line, as well as one option ``bar`` +(as you can see, options are given in the lines immediately following the +arguments and indicated by the colons). + +The directive content follows after a blank line and is indented relative to the +directive start. + + +Footnotes +--------- + +For footnotes, use ``[#]_`` to mark the footnote location, and add the footnote +body at the bottom of the document after a "Footnotes" rubric heading, like so:: + + Lorem ipsum [#]_ dolor sit amet ... [#]_ + + .. rubric:: Footnotes + + .. [#] Text of the first footnote. + .. [#] Text of the second footnote. + +You can also explicitly number the footnotes for better context. + + +Comments +-------- + +Every explicit markup block which isn't a valid markup construct (like the +footnotes above) is regarded as a comment. + + +Source encoding +--------------- + +Since the easiest way to include special characters like em dashes or copyright +signs in reST is to directly write them as Unicode characters, one has to +specify an encoding: + +All Python documentation source files must be in UTF-8 encoding, and the HTML +documents written from them will be in that encoding as well. + + +Gotchas +------- + +There are some problems one commonly runs into while authoring reST documents: + +* **Separation of inline markup:** As said above, inline markup spans must be + separated from the surrounding text by non-word characters, you have to use + an escaped space to get around that. + +.. XXX more? diff --git a/Doc/documenting/sphinx.rst b/Doc/documenting/sphinx.rst new file mode 100644 index 0000000..85e8b5e --- /dev/null +++ b/Doc/documenting/sphinx.rst @@ -0,0 +1,60 @@ +.. highlightlang:: rest + +The Sphinx build system +======================= + +.. XXX: intro... + +.. _doc-build-config: + +The build configuration file +---------------------------- + +The documentation root, that is the ``Doc`` subdirectory of the source +distribution, contains a file named ``conf.py``. This file is called the "build +configuration file", and it contains several variables that are read and used +during a build run. + +These variables are: + +version : string + A string that is used as a replacement for the ``|version|`` reST + substitution. It should be the Python version the documentation refers to. + This consists only of the major and minor version parts, e.g. ``2.5``, even + for version 2.5.1. + +release : string + A string that is used as a replacement for the ``|release|`` reST + substitution. It should be the full version string including + alpha/beta/release candidate tags, e.g. ``2.5.2b3``. + +Both ``release`` and ``version`` can be ``'auto'``, which means that they are +determined at runtime from the ``Include/patchlevel.h`` file, if a complete +Python source distribution can be found, or else from the interpreter running +Sphinx. + +today_fmt : string + A ``strftime`` format that is used to format a replacement for the + ``|today|`` reST substitution. + +today : string + A string that can contain a date that should be written to the documentation + output literally. If this is nonzero, it is used instead of + ``strftime(today_fmt)``. + +unused_files : list of strings + A list of reST filenames that are to be disregarded during building. This + could be docs for temporarily disabled modules or documentation that's not + yet ready for public consumption. + +last_updated_format : string + If this is not an empty string, it will be given to ``time.strftime()`` and + written to each generated output file after "last updated on:". + +use_smartypants : bool + If true, use SmartyPants to convert quotes and dashes to the typographically + correct entities. + +add_function_parentheses : bool + If true, ``()`` will be appended to the content of ``:func:``, ``:meth:`` and + ``:cfunc:`` cross-references. \ No newline at end of file diff --git a/Doc/documenting/style.rst b/Doc/documenting/style.rst new file mode 100644 index 0000000..5d0ccb7 --- /dev/null +++ b/Doc/documenting/style.rst @@ -0,0 +1,70 @@ +.. highlightlang:: rest + +Style Guide +=========== + +The Python documentation should follow the `Apple Publications Style Guide`_ +wherever possible. This particular style guide was selected mostly because it +seems reasonable and is easy to get online. + +Topics which are not covered in the Apple's style guide will be discussed in +this document. + +All reST files use an indentation of 3 spaces. The maximum line length is 80 +characters for normal text, but tables, deeply indented code samples and long +links may extend beyond that. + +Make generous use of blank lines where applicable; they help grouping things +together. + +A sentence-ending period may be followed by one or two spaces; while reST +ignores the second space, it is customarily put in by some users, for example +to aid Emacs' auto-fill mode. + +Footnotes are generally discouraged, though they may be used when they are the +best way to present specific information. When a footnote reference is added at +the end of the sentence, it should follow the sentence-ending punctuation. The +reST markup should appear something like this:: + + This sentence has a footnote reference. [#]_ This is the next sentence. + +Footnotes should be gathered at the end of a file, or if the file is very long, +at the end of a section. The docutils will automatically create backlinks to +the footnote reference. + +Footnotes may appear in the middle of sentences where appropriate. + +Many special names are used in the Python documentation, including the names of +operating systems, programming languages, standards bodies, and the like. Most +of these entities are not assigned any special markup, but the preferred +spellings are given here to aid authors in maintaining the consistency of +presentation in the Python documentation. + +Other terms and words deserve special mention as well; these conventions should +be used to ensure consistency throughout the documentation: + +CPU + For "central processing unit." Many style guides say this should be spelled + out on the first use (and if you must use it, do so!). For the Python + documentation, this abbreviation should be avoided since there's no + reasonable way to predict which occurrence will be the first seen by the + reader. It is better to use the word "processor" instead. + +POSIX + The name assigned to a particular group of standards. This is always + uppercase. + +Python + The name of our favorite programming language is always capitalized. + +Unicode + The name of a character set and matching encoding. This is always written + capitalized. + +Unix + The name of the operating system developed at AT&T Bell Labs in the early + 1970s. + + +.. _Apple Publications Style Guide: http://developer.apple.com/documentation/UserExperience/Conceptual/APStyleGuide/AppleStyleGuide2003.pdf + diff --git a/Doc/extending/building.rst b/Doc/extending/building.rst new file mode 100644 index 0000000..5e1dec8 --- /dev/null +++ b/Doc/extending/building.rst @@ -0,0 +1,131 @@ +.. highlightlang:: c + + +.. _building: + +******************************************** +Building C and C++ Extensions with distutils +******************************************** + +.. sectionauthor:: Martin v. Löwis + + +Starting in Python 1.4, Python provides, on Unix, a special make file for +building make files for building dynamically-linked extensions and custom +interpreters. Starting with Python 2.0, this mechanism (known as related to +Makefile.pre.in, and Setup files) is no longer supported. Building custom +interpreters was rarely used, and extension modules can be built using +distutils. + +Building an extension module using distutils requires that distutils is +installed on the build machine, which is included in Python 2.x and available +separately for Python 1.5. Since distutils also supports creation of binary +packages, users don't necessarily need a compiler and distutils to install the +extension. + +A distutils package contains a driver script, :file:`setup.py`. This is a plain +Python file, which, in the most simple case, could look like this:: + + from distutils.core import setup, Extension + + module1 = Extension('demo', + sources = ['demo.c']) + + setup (name = 'PackageName', + version = '1.0', + description = 'This is a demo package', + ext_modules = [module1]) + + +With this :file:`setup.py`, and a file :file:`demo.c`, running :: + + python setup.py build + +will compile :file:`demo.c`, and produce an extension module named ``demo`` in +the :file:`build` directory. Depending on the system, the module file will end +up in a subdirectory :file:`build/lib.system`, and may have a name like +:file:`demo.so` or :file:`demo.pyd`. + +In the :file:`setup.py`, all execution is performed by calling the ``setup`` +function. This takes a variable number of keyword arguments, of which the +example above uses only a subset. Specifically, the example specifies +meta-information to build packages, and it specifies the contents of the +package. Normally, a package will contain of addition modules, like Python +source modules, documentation, subpackages, etc. Please refer to the distutils +documentation in :ref:`distutils-index` to learn more about the features of +distutils; this section explains building extension modules only. + +It is common to pre-compute arguments to :func:`setup`, to better structure the +driver script. In the example above, the\ ``ext_modules`` argument to +:func:`setup` is a list of extension modules, each of which is an instance of +the :class:`Extension`. In the example, the instance defines an extension named +``demo`` which is build by compiling a single source file, :file:`demo.c`. + +In many cases, building an extension is more complex, since additional +preprocessor defines and libraries may be needed. This is demonstrated in the +example below. :: + + from distutils.core import setup, Extension + + module1 = Extension('demo', + define_macros = [('MAJOR_VERSION', '1'), + ('MINOR_VERSION', '0')], + include_dirs = ['/usr/local/include'], + libraries = ['tcl83'], + library_dirs = ['/usr/local/lib'], + sources = ['demo.c']) + + setup (name = 'PackageName', + version = '1.0', + description = 'This is a demo package', + author = 'Martin v. Loewis', + author_email = 'martin@v.loewis.de', + url = 'http://www.python.org/doc/current/ext/building.html', + long_description = ''' + This is really just a demo package. + ''', + ext_modules = [module1]) + + +In this example, :func:`setup` is called with additional meta-information, which +is recommended when distribution packages have to be built. For the extension +itself, it specifies preprocessor defines, include directories, library +directories, and libraries. Depending on the compiler, distutils passes this +information in different ways to the compiler. For example, on Unix, this may +result in the compilation commands :: + + gcc -DNDEBUG -g -O3 -Wall -Wstrict-prototypes -fPIC -DMAJOR_VERSION=1 -DMINOR_VERSION=0 -I/usr/local/include -I/usr/local/include/python2.2 -c demo.c -o build/temp.linux-i686-2.2/demo.o + + gcc -shared build/temp.linux-i686-2.2/demo.o -L/usr/local/lib -ltcl83 -o build/lib.linux-i686-2.2/demo.so + +These lines are for demonstration purposes only; distutils users should trust +that distutils gets the invocations right. + + +.. _distributing: + +Distributing your extension modules +=================================== + +When an extension has been successfully build, there are three ways to use it. + +End-users will typically want to install the module, they do so by running :: + + python setup.py install + +Module maintainers should produce source packages; to do so, they run :: + + python setup.py sdist + +In some cases, additional files need to be included in a source distribution; +this is done through a :file:`MANIFEST.in` file; see the distutils documentation +for details. + +If the source distribution has been build successfully, maintainers can also +create binary distributions. Depending on the platform, one of the following +commands can be used to do so. :: + + python setup.py bdist_wininst + python setup.py bdist_rpm + python setup.py bdist_dumb + diff --git a/Doc/extending/embedding.rst b/Doc/extending/embedding.rst new file mode 100644 index 0000000..b9a567c --- /dev/null +++ b/Doc/extending/embedding.rst @@ -0,0 +1,297 @@ +.. highlightlang:: c + + +.. _embedding: + +*************************************** +Embedding Python in Another Application +*************************************** + +The previous chapters discussed how to extend Python, that is, how to extend the +functionality of Python by attaching a library of C functions to it. It is also +possible to do it the other way around: enrich your C/C++ application by +embedding Python in it. Embedding provides your application with the ability to +implement some of the functionality of your application in Python rather than C +or C++. This can be used for many purposes; one example would be to allow users +to tailor the application to their needs by writing some scripts in Python. You +can also use it yourself if some of the functionality can be written in Python +more easily. + +Embedding Python is similar to extending it, but not quite. The difference is +that when you extend Python, the main program of the application is still the +Python interpreter, while if you embed Python, the main program may have nothing +to do with Python --- instead, some parts of the application occasionally call +the Python interpreter to run some Python code. + +So if you are embedding Python, you are providing your own main program. One of +the things this main program has to do is initialize the Python interpreter. At +the very least, you have to call the function :cfunc:`Py_Initialize` (on Mac OS, +call :cfunc:`PyMac_Initialize` instead). There are optional calls to pass +command line arguments to Python. Then later you can call the interpreter from +any part of the application. + +There are several different ways to call the interpreter: you can pass a string +containing Python statements to :cfunc:`PyRun_SimpleString`, or you can pass a +stdio file pointer and a file name (for identification in error messages only) +to :cfunc:`PyRun_SimpleFile`. You can also call the lower-level operations +described in the previous chapters to construct and use Python objects. + +A simple demo of embedding Python can be found in the directory +:file:`Demo/embed/` of the source distribution. + + +.. seealso:: + + :ref:`c-api-index` + The details of Python's C interface are given in this manual. A great deal of + necessary information can be found here. + + +.. _high-level-embedding: + +Very High Level Embedding +========================= + +The simplest form of embedding Python is the use of the very high level +interface. This interface is intended to execute a Python script without needing +to interact with the application directly. This can for example be used to +perform some operation on a file. :: + + #include + + int + main(int argc, char *argv[]) + { + Py_Initialize(); + PyRun_SimpleString("from time import time,ctime\n" + "print 'Today is',ctime(time())\n"); + Py_Finalize(); + return 0; + } + +The above code first initializes the Python interpreter with +:cfunc:`Py_Initialize`, followed by the execution of a hard-coded Python script +that print the date and time. Afterwards, the :cfunc:`Py_Finalize` call shuts +the interpreter down, followed by the end of the program. In a real program, +you may want to get the Python script from another source, perhaps a text-editor +routine, a file, or a database. Getting the Python code from a file can better +be done by using the :cfunc:`PyRun_SimpleFile` function, which saves you the +trouble of allocating memory space and loading the file contents. + + +.. _lower-level-embedding: + +Beyond Very High Level Embedding: An overview +============================================= + +The high level interface gives you the ability to execute arbitrary pieces of +Python code from your application, but exchanging data values is quite +cumbersome to say the least. If you want that, you should use lower level calls. +At the cost of having to write more C code, you can achieve almost anything. + +It should be noted that extending Python and embedding Python is quite the same +activity, despite the different intent. Most topics discussed in the previous +chapters are still valid. To show this, consider what the extension code from +Python to C really does: + +#. Convert data values from Python to C, + +#. Perform a function call to a C routine using the converted values, and + +#. Convert the data values from the call from C to Python. + +When embedding Python, the interface code does: + +#. Convert data values from C to Python, + +#. Perform a function call to a Python interface routine using the converted + values, and + +#. Convert the data values from the call from Python to C. + +As you can see, the data conversion steps are simply swapped to accommodate the +different direction of the cross-language transfer. The only difference is the +routine that you call between both data conversions. When extending, you call a +C routine, when embedding, you call a Python routine. + +This chapter will not discuss how to convert data from Python to C and vice +versa. Also, proper use of references and dealing with errors is assumed to be +understood. Since these aspects do not differ from extending the interpreter, +you can refer to earlier chapters for the required information. + + +.. _pure-embedding: + +Pure Embedding +============== + +The first program aims to execute a function in a Python script. Like in the +section about the very high level interface, the Python interpreter does not +directly interact with the application (but that will change in the next +section). + +The code to run a function defined in a Python script is: + +.. literalinclude:: ../includes/run-func.c + + +This code loads a Python script using ``argv[1]``, and calls the function named +in ``argv[2]``. Its integer arguments are the other values of the ``argv`` +array. If you compile and link this program (let's call the finished executable +:program:`call`), and use it to execute a Python script, such as:: + + def multiply(a,b): + print "Will compute", a, "times", b + c = 0 + for i in range(0, a): + c = c + b + return c + +then the result should be:: + + $ call multiply multiply 3 2 + Will compute 3 times 2 + Result of call: 6 + +Although the program is quite large for its functionality, most of the code is +for data conversion between Python and C, and for error reporting. The +interesting part with respect to embedding Python starts with + +.. % $ + +:: + + Py_Initialize(); + pName = PyString_FromString(argv[1]); + /* Error checking of pName left out */ + pModule = PyImport_Import(pName); + +After initializing the interpreter, the script is loaded using +:cfunc:`PyImport_Import`. This routine needs a Python string as its argument, +which is constructed using the :cfunc:`PyString_FromString` data conversion +routine. :: + + pFunc = PyObject_GetAttrString(pModule, argv[2]); + /* pFunc is a new reference */ + + if (pFunc && PyCallable_Check(pFunc)) { + ... + } + Py_XDECREF(pFunc); + +Once the script is loaded, the name we're looking for is retrieved using +:cfunc:`PyObject_GetAttrString`. If the name exists, and the object returned is +callable, you can safely assume that it is a function. The program then +proceeds by constructing a tuple of arguments as normal. The call to the Python +function is then made with:: + + pValue = PyObject_CallObject(pFunc, pArgs); + +Upon return of the function, ``pValue`` is either *NULL* or it contains a +reference to the return value of the function. Be sure to release the reference +after examining the value. + + +.. _extending-with-embedding: + +Extending Embedded Python +========================= + +Until now, the embedded Python interpreter had no access to functionality from +the application itself. The Python API allows this by extending the embedded +interpreter. That is, the embedded interpreter gets extended with routines +provided by the application. While it sounds complex, it is not so bad. Simply +forget for a while that the application starts the Python interpreter. Instead, +consider the application to be a set of subroutines, and write some glue code +that gives Python access to those routines, just like you would write a normal +Python extension. For example:: + + static int numargs=0; + + /* Return the number of arguments of the application command line */ + static PyObject* + emb_numargs(PyObject *self, PyObject *args) + { + if(!PyArg_ParseTuple(args, ":numargs")) + return NULL; + return Py_BuildValue("i", numargs); + } + + static PyMethodDef EmbMethods[] = { + {"numargs", emb_numargs, METH_VARARGS, + "Return the number of arguments received by the process."}, + {NULL, NULL, 0, NULL} + }; + +Insert the above code just above the :cfunc:`main` function. Also, insert the +following two statements directly after :cfunc:`Py_Initialize`:: + + numargs = argc; + Py_InitModule("emb", EmbMethods); + +These two lines initialize the ``numargs`` variable, and make the +:func:`emb.numargs` function accessible to the embedded Python interpreter. +With these extensions, the Python script can do things like :: + + import emb + print "Number of arguments", emb.numargs() + +In a real application, the methods will expose an API of the application to +Python. + +.. % \section{For the future} +.. % +.. % You don't happen to have a nice library to get textual +.. % equivalents of numeric values do you :-) ? +.. % Callbacks here ? (I may be using information from that section +.. % ?!) +.. % threads +.. % code examples do not really behave well if errors happen +.. % (what to watch out for) + + +.. _embeddingincplusplus: + +Embedding Python in C++ +======================= + +It is also possible to embed Python in a C++ program; precisely how this is done +will depend on the details of the C++ system used; in general you will need to +write the main program in C++, and use the C++ compiler to compile and link your +program. There is no need to recompile Python itself using C++. + + +.. _link-reqs: + +Linking Requirements +==================== + +While the :program:`configure` script shipped with the Python sources will +correctly build Python to export the symbols needed by dynamically linked +extensions, this is not automatically inherited by applications which embed the +Python library statically, at least on Unix. This is an issue when the +application is linked to the static runtime library (:file:`libpython.a`) and +needs to load dynamic extensions (implemented as :file:`.so` files). + +The problem is that some entry points are defined by the Python runtime solely +for extension modules to use. If the embedding application does not use any of +these entry points, some linkers will not include those entries in the symbol +table of the finished executable. Some additional options are needed to inform +the linker not to remove these symbols. + +Determining the right options to use for any given platform can be quite +difficult, but fortunately the Python configuration already has those values. +To retrieve them from an installed Python interpreter, start an interactive +interpreter and have a short session like this:: + + >>> import distutils.sysconfig + >>> distutils.sysconfig.get_config_var('LINKFORSHARED') + '-Xlinker -export-dynamic' + +.. index:: module: distutils.sysconfig + +The contents of the string presented will be the options that should be used. +If the string is empty, there's no need to add any additional options. The +:const:`LINKFORSHARED` definition corresponds to the variable of the same name +in Python's top-level :file:`Makefile`. + diff --git a/Doc/extending/extending.rst b/Doc/extending/extending.rst new file mode 100644 index 0000000..bf48c49 --- /dev/null +++ b/Doc/extending/extending.rst @@ -0,0 +1,1273 @@ +.. highlightlang:: c + + +.. _extending-intro: + +****************************** +Extending Python with C or C++ +****************************** + +It is quite easy to add new built-in modules to Python, if you know how to +program in C. Such :dfn:`extension modules` can do two things that can't be +done directly in Python: they can implement new built-in object types, and they +can call C library functions and system calls. + +To support extensions, the Python API (Application Programmers Interface) +defines a set of functions, macros and variables that provide access to most +aspects of the Python run-time system. The Python API is incorporated in a C +source file by including the header ``"Python.h"``. + +The compilation of an extension module depends on its intended use as well as on +your system setup; details are given in later chapters. + + +.. _extending-simpleexample: + +A Simple Example +================ + +Let's create an extension module called ``spam`` (the favorite food of Monty +Python fans...) and let's say we want to create a Python interface to the C +library function :cfunc:`system`. [#]_ This function takes a null-terminated +character string as argument and returns an integer. We want this function to +be callable from Python as follows:: + + >>> import spam + >>> status = spam.system("ls -l") + +Begin by creating a file :file:`spammodule.c`. (Historically, if a module is +called ``spam``, the C file containing its implementation is called +:file:`spammodule.c`; if the module name is very long, like ``spammify``, the +module name can be just :file:`spammify.c`.) + +The first line of our file can be:: + + #include + +which pulls in the Python API (you can add a comment describing the purpose of +the module and a copyright notice if you like). + +.. warning:: + + Since Python may define some pre-processor definitions which affect the standard + headers on some systems, you *must* include :file:`Python.h` before any standard + headers are included. + +All user-visible symbols defined by :file:`Python.h` have a prefix of ``Py`` or +``PY``, except those defined in standard header files. For convenience, and +since they are used extensively by the Python interpreter, ``"Python.h"`` +includes a few standard header files: ````, ````, +````, and ````. If the latter header file does not exist on +your system, it declares the functions :cfunc:`malloc`, :cfunc:`free` and +:cfunc:`realloc` directly. + +The next thing we add to our module file is the C function that will be called +when the Python expression ``spam.system(string)`` is evaluated (we'll see +shortly how it ends up being called):: + + static PyObject * + spam_system(PyObject *self, PyObject *args) + { + const char *command; + int sts; + + if (!PyArg_ParseTuple(args, "s", &command)) + return NULL; + sts = system(command); + return Py_BuildValue("i", sts); + } + +There is a straightforward translation from the argument list in Python (for +example, the single expression ``"ls -l"``) to the arguments passed to the C +function. The C function always has two arguments, conventionally named *self* +and *args*. + +The *self* argument is only used when the C function implements a built-in +method, not a function. In the example, *self* will always be a *NULL* pointer, +since we are defining a function, not a method. (This is done so that the +interpreter doesn't have to understand two different types of C functions.) + +The *args* argument will be a pointer to a Python tuple object containing the +arguments. Each item of the tuple corresponds to an argument in the call's +argument list. The arguments are Python objects --- in order to do anything +with them in our C function we have to convert them to C values. The function +:cfunc:`PyArg_ParseTuple` in the Python API checks the argument types and +converts them to C values. It uses a template string to determine the required +types of the arguments as well as the types of the C variables into which to +store the converted values. More about this later. + +:cfunc:`PyArg_ParseTuple` returns true (nonzero) if all arguments have the right +type and its components have been stored in the variables whose addresses are +passed. It returns false (zero) if an invalid argument list was passed. In the +latter case it also raises an appropriate exception so the calling function can +return *NULL* immediately (as we saw in the example). + + +.. _extending-errors: + +Intermezzo: Errors and Exceptions +================================= + +An important convention throughout the Python interpreter is the following: when +a function fails, it should set an exception condition and return an error value +(usually a *NULL* pointer). Exceptions are stored in a static global variable +inside the interpreter; if this variable is *NULL* no exception has occurred. A +second global variable stores the "associated value" of the exception (the +second argument to :keyword:`raise`). A third variable contains the stack +traceback in case the error originated in Python code. These three variables +are the C equivalents of the result in Python of :meth:`sys.exc_info` (see the +section on module :mod:`sys` in the Python Library Reference). It is important +to know about them to understand how errors are passed around. + +The Python API defines a number of functions to set various types of exceptions. + +The most common one is :cfunc:`PyErr_SetString`. Its arguments are an exception +object and a C string. The exception object is usually a predefined object like +:cdata:`PyExc_ZeroDivisionError`. The C string indicates the cause of the error +and is converted to a Python string object and stored as the "associated value" +of the exception. + +Another useful function is :cfunc:`PyErr_SetFromErrno`, which only takes an +exception argument and constructs the associated value by inspection of the +global variable :cdata:`errno`. The most general function is +:cfunc:`PyErr_SetObject`, which takes two object arguments, the exception and +its associated value. You don't need to :cfunc:`Py_INCREF` the objects passed +to any of these functions. + +You can test non-destructively whether an exception has been set with +:cfunc:`PyErr_Occurred`. This returns the current exception object, or *NULL* +if no exception has occurred. You normally don't need to call +:cfunc:`PyErr_Occurred` to see whether an error occurred in a function call, +since you should be able to tell from the return value. + +When a function *f* that calls another function *g* detects that the latter +fails, *f* should itself return an error value (usually *NULL* or ``-1``). It +should *not* call one of the :cfunc:`PyErr_\*` functions --- one has already +been called by *g*. *f*'s caller is then supposed to also return an error +indication to *its* caller, again *without* calling :cfunc:`PyErr_\*`, and so on +--- the most detailed cause of the error was already reported by the function +that first detected it. Once the error reaches the Python interpreter's main +loop, this aborts the currently executing Python code and tries to find an +exception handler specified by the Python programmer. + +(There are situations where a module can actually give a more detailed error +message by calling another :cfunc:`PyErr_\*` function, and in such cases it is +fine to do so. As a general rule, however, this is not necessary, and can cause +information about the cause of the error to be lost: most operations can fail +for a variety of reasons.) + +To ignore an exception set by a function call that failed, the exception +condition must be cleared explicitly by calling :cfunc:`PyErr_Clear`. The only +time C code should call :cfunc:`PyErr_Clear` is if it doesn't want to pass the +error on to the interpreter but wants to handle it completely by itself +(possibly by trying something else, or pretending nothing went wrong). + +Every failing :cfunc:`malloc` call must be turned into an exception --- the +direct caller of :cfunc:`malloc` (or :cfunc:`realloc`) must call +:cfunc:`PyErr_NoMemory` and return a failure indicator itself. All the +object-creating functions (for example, :cfunc:`PyInt_FromLong`) already do +this, so this note is only relevant to those who call :cfunc:`malloc` directly. + +Also note that, with the important exception of :cfunc:`PyArg_ParseTuple` and +friends, functions that return an integer status usually return a positive value +or zero for success and ``-1`` for failure, like Unix system calls. + +Finally, be careful to clean up garbage (by making :cfunc:`Py_XDECREF` or +:cfunc:`Py_DECREF` calls for objects you have already created) when you return +an error indicator! + +The choice of which exception to raise is entirely yours. There are predeclared +C objects corresponding to all built-in Python exceptions, such as +:cdata:`PyExc_ZeroDivisionError`, which you can use directly. Of course, you +should choose exceptions wisely --- don't use :cdata:`PyExc_TypeError` to mean +that a file couldn't be opened (that should probably be :cdata:`PyExc_IOError`). +If something's wrong with the argument list, the :cfunc:`PyArg_ParseTuple` +function usually raises :cdata:`PyExc_TypeError`. If you have an argument whose +value must be in a particular range or must satisfy other conditions, +:cdata:`PyExc_ValueError` is appropriate. + +You can also define a new exception that is unique to your module. For this, you +usually declare a static object variable at the beginning of your file:: + + static PyObject *SpamError; + +and initialize it in your module's initialization function (:cfunc:`initspam`) +with an exception object (leaving out the error checking for now):: + + PyMODINIT_FUNC + initspam(void) + { + PyObject *m; + + m = Py_InitModule("spam", SpamMethods); + if (m == NULL) + return; + + SpamError = PyErr_NewException("spam.error", NULL, NULL); + Py_INCREF(SpamError); + PyModule_AddObject(m, "error", SpamError); + } + +Note that the Python name for the exception object is :exc:`spam.error`. The +:cfunc:`PyErr_NewException` function may create a class with the base class +being :exc:`Exception` (unless another class is passed in instead of *NULL*), +described in :ref:`bltin-exceptions`. + +Note also that the :cdata:`SpamError` variable retains a reference to the newly +created exception class; this is intentional! Since the exception could be +removed from the module by external code, an owned reference to the class is +needed to ensure that it will not be discarded, causing :cdata:`SpamError` to +become a dangling pointer. Should it become a dangling pointer, C code which +raises the exception could cause a core dump or other unintended side effects. + +We discuss the use of PyMODINIT_FUNC as a function return type later in this +sample. + + +.. _backtoexample: + +Back to the Example +=================== + +Going back to our example function, you should now be able to understand this +statement:: + + if (!PyArg_ParseTuple(args, "s", &command)) + return NULL; + +It returns *NULL* (the error indicator for functions returning object pointers) +if an error is detected in the argument list, relying on the exception set by +:cfunc:`PyArg_ParseTuple`. Otherwise the string value of the argument has been +copied to the local variable :cdata:`command`. This is a pointer assignment and +you are not supposed to modify the string to which it points (so in Standard C, +the variable :cdata:`command` should properly be declared as ``const char +*command``). + +The next statement is a call to the Unix function :cfunc:`system`, passing it +the string we just got from :cfunc:`PyArg_ParseTuple`:: + + sts = system(command); + +Our :func:`spam.system` function must return the value of :cdata:`sts` as a +Python object. This is done using the function :cfunc:`Py_BuildValue`, which is +something like the inverse of :cfunc:`PyArg_ParseTuple`: it takes a format +string and an arbitrary number of C values, and returns a new Python object. +More info on :cfunc:`Py_BuildValue` is given later. :: + + return Py_BuildValue("i", sts); + +In this case, it will return an integer object. (Yes, even integers are objects +on the heap in Python!) + +If you have a C function that returns no useful argument (a function returning +:ctype:`void`), the corresponding Python function must return ``None``. You +need this idiom to do so (which is implemented by the :cmacro:`Py_RETURN_NONE` +macro):: + + Py_INCREF(Py_None); + return Py_None; + +:cdata:`Py_None` is the C name for the special Python object ``None``. It is a +genuine Python object rather than a *NULL* pointer, which means "error" in most +contexts, as we have seen. + + +.. _methodtable: + +The Module's Method Table and Initialization Function +===================================================== + +I promised to show how :cfunc:`spam_system` is called from Python programs. +First, we need to list its name and address in a "method table":: + + static PyMethodDef SpamMethods[] = { + ... + {"system", spam_system, METH_VARARGS, + "Execute a shell command."}, + ... + {NULL, NULL, 0, NULL} /* Sentinel */ + }; + +Note the third entry (``METH_VARARGS``). This is a flag telling the interpreter +the calling convention to be used for the C function. It should normally always +be ``METH_VARARGS`` or ``METH_VARARGS | METH_KEYWORDS``; a value of ``0`` means +that an obsolete variant of :cfunc:`PyArg_ParseTuple` is used. + +When using only ``METH_VARARGS``, the function should expect the Python-level +parameters to be passed in as a tuple acceptable for parsing via +:cfunc:`PyArg_ParseTuple`; more information on this function is provided below. + +The :const:`METH_KEYWORDS` bit may be set in the third field if keyword +arguments should be passed to the function. In this case, the C function should +accept a third ``PyObject *`` parameter which will be a dictionary of keywords. +Use :cfunc:`PyArg_ParseTupleAndKeywords` to parse the arguments to such a +function. + +The method table must be passed to the interpreter in the module's +initialization function. The initialization function must be named +:cfunc:`initname`, where *name* is the name of the module, and should be the +only non-\ :keyword:`static` item defined in the module file:: + + PyMODINIT_FUNC + initspam(void) + { + (void) Py_InitModule("spam", SpamMethods); + } + +Note that PyMODINIT_FUNC declares the function as ``void`` return type, +declares any special linkage declarations required by the platform, and for C++ +declares the function as ``extern "C"``. + +When the Python program imports module :mod:`spam` for the first time, +:cfunc:`initspam` is called. (See below for comments about embedding Python.) +It calls :cfunc:`Py_InitModule`, which creates a "module object" (which is +inserted in the dictionary ``sys.modules`` under the key ``"spam"``), and +inserts built-in function objects into the newly created module based upon the +table (an array of :ctype:`PyMethodDef` structures) that was passed as its +second argument. :cfunc:`Py_InitModule` returns a pointer to the module object +that it creates (which is unused here). It may abort with a fatal error for +certain errors, or return *NULL* if the module could not be initialized +satisfactorily. + +When embedding Python, the :cfunc:`initspam` function is not called +automatically unless there's an entry in the :cdata:`_PyImport_Inittab` table. +The easiest way to handle this is to statically initialize your +statically-linked modules by directly calling :cfunc:`initspam` after the call +to :cfunc:`Py_Initialize`:: + + int + main(int argc, char *argv[]) + { + /* Pass argv[0] to the Python interpreter */ + Py_SetProgramName(argv[0]); + + /* Initialize the Python interpreter. Required. */ + Py_Initialize(); + + /* Add a static module */ + initspam(); + +An example may be found in the file :file:`Demo/embed/demo.c` in the Python +source distribution. + +.. note:: + + Removing entries from ``sys.modules`` or importing compiled modules into + multiple interpreters within a process (or following a :cfunc:`fork` without an + intervening :cfunc:`exec`) can create problems for some extension modules. + Extension module authors should exercise caution when initializing internal data + structures. + +A more substantial example module is included in the Python source distribution +as :file:`Modules/xxmodule.c`. This file may be used as a template or simply +read as an example. The :program:`modulator.py` script included in the source +distribution or Windows install provides a simple graphical user interface for +declaring the functions and objects which a module should implement, and can +generate a template which can be filled in. The script lives in the +:file:`Tools/modulator/` directory; see the :file:`README` file there for more +information. + + +.. _compilation: + +Compilation and Linkage +======================= + +There are two more things to do before you can use your new extension: compiling +and linking it with the Python system. If you use dynamic loading, the details +may depend on the style of dynamic loading your system uses; see the chapters +about building extension modules (chapter :ref:`building`) and additional +information that pertains only to building on Windows (chapter +:ref:`building-on-windows`) for more information about this. + +If you can't use dynamic loading, or if you want to make your module a permanent +part of the Python interpreter, you will have to change the configuration setup +and rebuild the interpreter. Luckily, this is very simple on Unix: just place +your file (:file:`spammodule.c` for example) in the :file:`Modules/` directory +of an unpacked source distribution, add a line to the file +:file:`Modules/Setup.local` describing your file:: + + spam spammodule.o + +and rebuild the interpreter by running :program:`make` in the toplevel +directory. You can also run :program:`make` in the :file:`Modules/` +subdirectory, but then you must first rebuild :file:`Makefile` there by running +':program:`make` Makefile'. (This is necessary each time you change the +:file:`Setup` file.) + +If your module requires additional libraries to link with, these can be listed +on the line in the configuration file as well, for instance:: + + spam spammodule.o -lX11 + + +.. _callingpython: + +Calling Python Functions from C +=============================== + +So far we have concentrated on making C functions callable from Python. The +reverse is also useful: calling Python functions from C. This is especially the +case for libraries that support so-called "callback" functions. If a C +interface makes use of callbacks, the equivalent Python often needs to provide a +callback mechanism to the Python programmer; the implementation will require +calling the Python callback functions from a C callback. Other uses are also +imaginable. + +Fortunately, the Python interpreter is easily called recursively, and there is a +standard interface to call a Python function. (I won't dwell on how to call the +Python parser with a particular string as input --- if you're interested, have a +look at the implementation of the :option:`-c` command line option in +:file:`Python/pythonmain.c` from the Python source code.) + +Calling a Python function is easy. First, the Python program must somehow pass +you the Python function object. You should provide a function (or some other +interface) to do this. When this function is called, save a pointer to the +Python function object (be careful to :cfunc:`Py_INCREF` it!) in a global +variable --- or wherever you see fit. For example, the following function might +be part of a module definition:: + + static PyObject *my_callback = NULL; + + static PyObject * + my_set_callback(PyObject *dummy, PyObject *args) + { + PyObject *result = NULL; + PyObject *temp; + + if (PyArg_ParseTuple(args, "O:set_callback", &temp)) { + if (!PyCallable_Check(temp)) { + PyErr_SetString(PyExc_TypeError, "parameter must be callable"); + return NULL; + } + Py_XINCREF(temp); /* Add a reference to new callback */ + Py_XDECREF(my_callback); /* Dispose of previous callback */ + my_callback = temp; /* Remember new callback */ + /* Boilerplate to return "None" */ + Py_INCREF(Py_None); + result = Py_None; + } + return result; + } + +This function must be registered with the interpreter using the +:const:`METH_VARARGS` flag; this is described in section :ref:`methodtable`. The +:cfunc:`PyArg_ParseTuple` function and its arguments are documented in section +:ref:`parsetuple`. + +The macros :cfunc:`Py_XINCREF` and :cfunc:`Py_XDECREF` increment/decrement the +reference count of an object and are safe in the presence of *NULL* pointers +(but note that *temp* will not be *NULL* in this context). More info on them +in section :ref:`refcounts`. + +.. index:: single: PyEval_CallObject() + +Later, when it is time to call the function, you call the C function +:cfunc:`PyEval_CallObject`. This function has two arguments, both pointers to +arbitrary Python objects: the Python function, and the argument list. The +argument list must always be a tuple object, whose length is the number of +arguments. To call the Python function with no arguments, pass an empty tuple; +to call it with one argument, pass a singleton tuple. :cfunc:`Py_BuildValue` +returns a tuple when its format string consists of zero or more format codes +between parentheses. For example:: + + int arg; + PyObject *arglist; + PyObject *result; + ... + arg = 123; + ... + /* Time to call the callback */ + arglist = Py_BuildValue("(i)", arg); + result = PyEval_CallObject(my_callback, arglist); + Py_DECREF(arglist); + +:cfunc:`PyEval_CallObject` returns a Python object pointer: this is the return +value of the Python function. :cfunc:`PyEval_CallObject` is +"reference-count-neutral" with respect to its arguments. In the example a new +tuple was created to serve as the argument list, which is :cfunc:`Py_DECREF`\ +-ed immediately after the call. + +The return value of :cfunc:`PyEval_CallObject` is "new": either it is a brand +new object, or it is an existing object whose reference count has been +incremented. So, unless you want to save it in a global variable, you should +somehow :cfunc:`Py_DECREF` the result, even (especially!) if you are not +interested in its value. + +Before you do this, however, it is important to check that the return value +isn't *NULL*. If it is, the Python function terminated by raising an exception. +If the C code that called :cfunc:`PyEval_CallObject` is called from Python, it +should now return an error indication to its Python caller, so the interpreter +can print a stack trace, or the calling Python code can handle the exception. +If this is not possible or desirable, the exception should be cleared by calling +:cfunc:`PyErr_Clear`. For example:: + + if (result == NULL) + return NULL; /* Pass error back */ + ...use result... + Py_DECREF(result); + +Depending on the desired interface to the Python callback function, you may also +have to provide an argument list to :cfunc:`PyEval_CallObject`. In some cases +the argument list is also provided by the Python program, through the same +interface that specified the callback function. It can then be saved and used +in the same manner as the function object. In other cases, you may have to +construct a new tuple to pass as the argument list. The simplest way to do this +is to call :cfunc:`Py_BuildValue`. For example, if you want to pass an integral +event code, you might use the following code:: + + PyObject *arglist; + ... + arglist = Py_BuildValue("(l)", eventcode); + result = PyEval_CallObject(my_callback, arglist); + Py_DECREF(arglist); + if (result == NULL) + return NULL; /* Pass error back */ + /* Here maybe use the result */ + Py_DECREF(result); + +Note the placement of ``Py_DECREF(arglist)`` immediately after the call, before +the error check! Also note that strictly spoken this code is not complete: +:cfunc:`Py_BuildValue` may run out of memory, and this should be checked. + + +.. _parsetuple: + +Extracting Parameters in Extension Functions +============================================ + +.. index:: single: PyArg_ParseTuple() + +The :cfunc:`PyArg_ParseTuple` function is declared as follows:: + + int PyArg_ParseTuple(PyObject *arg, char *format, ...); + +The *arg* argument must be a tuple object containing an argument list passed +from Python to a C function. The *format* argument must be a format string, +whose syntax is explained in :ref:`arg-parsing` in the Python/C API Reference +Manual. The remaining arguments must be addresses of variables whose type is +determined by the format string. + +Note that while :cfunc:`PyArg_ParseTuple` checks that the Python arguments have +the required types, it cannot check the validity of the addresses of C variables +passed to the call: if you make mistakes there, your code will probably crash or +at least overwrite random bits in memory. So be careful! + +Note that any Python object references which are provided to the caller are +*borrowed* references; do not decrement their reference count! + +Some example calls:: + + int ok; + int i, j; + long k, l; + const char *s; + int size; + + ok = PyArg_ParseTuple(args, ""); /* No arguments */ + /* Python call: f() */ + +:: + + ok = PyArg_ParseTuple(args, "s", &s); /* A string */ + /* Possible Python call: f('whoops!') */ + +:: + + ok = PyArg_ParseTuple(args, "lls", &k, &l, &s); /* Two longs and a string */ + /* Possible Python call: f(1, 2, 'three') */ + +:: + + ok = PyArg_ParseTuple(args, "(ii)s#", &i, &j, &s, &size); + /* A pair of ints and a string, whose size is also returned */ + /* Possible Python call: f((1, 2), 'three') */ + +:: + + { + const char *file; + const char *mode = "r"; + int bufsize = 0; + ok = PyArg_ParseTuple(args, "s|si", &file, &mode, &bufsize); + /* A string, and optionally another string and an integer */ + /* Possible Python calls: + f('spam') + f('spam', 'w') + f('spam', 'wb', 100000) */ + } + +:: + + { + int left, top, right, bottom, h, v; + ok = PyArg_ParseTuple(args, "((ii)(ii))(ii)", + &left, &top, &right, &bottom, &h, &v); + /* A rectangle and a point */ + /* Possible Python call: + f(((0, 0), (400, 300)), (10, 10)) */ + } + +:: + + { + Py_complex c; + ok = PyArg_ParseTuple(args, "D:myfunction", &c); + /* a complex, also providing a function name for errors */ + /* Possible Python call: myfunction(1+2j) */ + } + + +.. _parsetupleandkeywords: + +Keyword Parameters for Extension Functions +========================================== + +.. index:: single: PyArg_ParseTupleAndKeywords() + +The :cfunc:`PyArg_ParseTupleAndKeywords` function is declared as follows:: + + int PyArg_ParseTupleAndKeywords(PyObject *arg, PyObject *kwdict, + char *format, char *kwlist[], ...); + +The *arg* and *format* parameters are identical to those of the +:cfunc:`PyArg_ParseTuple` function. The *kwdict* parameter is the dictionary of +keywords received as the third parameter from the Python runtime. The *kwlist* +parameter is a *NULL*-terminated list of strings which identify the parameters; +the names are matched with the type information from *format* from left to +right. On success, :cfunc:`PyArg_ParseTupleAndKeywords` returns true, otherwise +it returns false and raises an appropriate exception. + +.. note:: + + Nested tuples cannot be parsed when using keyword arguments! Keyword parameters + passed in which are not present in the *kwlist* will cause :exc:`TypeError` to + be raised. + +.. index:: single: Philbrick, Geoff + +Here is an example module which uses keywords, based on an example by Geoff +Philbrick (philbrick@hks.com): + +.. % + +:: + + #include "Python.h" + + static PyObject * + keywdarg_parrot(PyObject *self, PyObject *args, PyObject *keywds) + { + int voltage; + char *state = "a stiff"; + char *action = "voom"; + char *type = "Norwegian Blue"; + + static char *kwlist[] = {"voltage", "state", "action", "type", NULL}; + + if (!PyArg_ParseTupleAndKeywords(args, keywds, "i|sss", kwlist, + &voltage, &state, &action, &type)) + return NULL; + + printf("-- This parrot wouldn't %s if you put %i Volts through it.\n", + action, voltage); + printf("-- Lovely plumage, the %s -- It's %s!\n", type, state); + + Py_INCREF(Py_None); + + return Py_None; + } + + static PyMethodDef keywdarg_methods[] = { + /* The cast of the function is necessary since PyCFunction values + * only take two PyObject* parameters, and keywdarg_parrot() takes + * three. + */ + {"parrot", (PyCFunction)keywdarg_parrot, METH_VARARGS | METH_KEYWORDS, + "Print a lovely skit to standard output."}, + {NULL, NULL, 0, NULL} /* sentinel */ + }; + +:: + + void + initkeywdarg(void) + { + /* Create the module and add the functions */ + Py_InitModule("keywdarg", keywdarg_methods); + } + + +.. _buildvalue: + +Building Arbitrary Values +========================= + +This function is the counterpart to :cfunc:`PyArg_ParseTuple`. It is declared +as follows:: + + PyObject *Py_BuildValue(char *format, ...); + +It recognizes a set of format units similar to the ones recognized by +:cfunc:`PyArg_ParseTuple`, but the arguments (which are input to the function, +not output) must not be pointers, just values. It returns a new Python object, +suitable for returning from a C function called from Python. + +One difference with :cfunc:`PyArg_ParseTuple`: while the latter requires its +first argument to be a tuple (since Python argument lists are always represented +as tuples internally), :cfunc:`Py_BuildValue` does not always build a tuple. It +builds a tuple only if its format string contains two or more format units. If +the format string is empty, it returns ``None``; if it contains exactly one +format unit, it returns whatever object is described by that format unit. To +force it to return a tuple of size 0 or one, parenthesize the format string. + +Examples (to the left the call, to the right the resulting Python value):: + + Py_BuildValue("") None + Py_BuildValue("i", 123) 123 + Py_BuildValue("iii", 123, 456, 789) (123, 456, 789) + Py_BuildValue("s", "hello") 'hello' + Py_BuildValue("y", "hello") b'hello' + Py_BuildValue("ss", "hello", "world") ('hello', 'world') + Py_BuildValue("s#", "hello", 4) 'hell' + Py_BuildValue("y#", "hello", 4) b'hell' + Py_BuildValue("()") () + Py_BuildValue("(i)", 123) (123,) + Py_BuildValue("(ii)", 123, 456) (123, 456) + Py_BuildValue("(i,i)", 123, 456) (123, 456) + Py_BuildValue("[i,i]", 123, 456) [123, 456] + Py_BuildValue("{s:i,s:i}", + "abc", 123, "def", 456) {'abc': 123, 'def': 456} + Py_BuildValue("((ii)(ii)) (ii)", + 1, 2, 3, 4, 5, 6) (((1, 2), (3, 4)), (5, 6)) + + +.. _refcounts: + +Reference Counts +================ + +In languages like C or C++, the programmer is responsible for dynamic allocation +and deallocation of memory on the heap. In C, this is done using the functions +:cfunc:`malloc` and :cfunc:`free`. In C++, the operators :keyword:`new` and +:keyword:`delete` are used with essentially the same meaning and we'll restrict +the following discussion to the C case. + +Every block of memory allocated with :cfunc:`malloc` should eventually be +returned to the pool of available memory by exactly one call to :cfunc:`free`. +It is important to call :cfunc:`free` at the right time. If a block's address +is forgotten but :cfunc:`free` is not called for it, the memory it occupies +cannot be reused until the program terminates. This is called a :dfn:`memory +leak`. On the other hand, if a program calls :cfunc:`free` for a block and then +continues to use the block, it creates a conflict with re-use of the block +through another :cfunc:`malloc` call. This is called :dfn:`using freed memory`. +It has the same bad consequences as referencing uninitialized data --- core +dumps, wrong results, mysterious crashes. + +Common causes of memory leaks are unusual paths through the code. For instance, +a function may allocate a block of memory, do some calculation, and then free +the block again. Now a change in the requirements for the function may add a +test to the calculation that detects an error condition and can return +prematurely from the function. It's easy to forget to free the allocated memory +block when taking this premature exit, especially when it is added later to the +code. Such leaks, once introduced, often go undetected for a long time: the +error exit is taken only in a small fraction of all calls, and most modern +machines have plenty of virtual memory, so the leak only becomes apparent in a +long-running process that uses the leaking function frequently. Therefore, it's +important to prevent leaks from happening by having a coding convention or +strategy that minimizes this kind of errors. + +Since Python makes heavy use of :cfunc:`malloc` and :cfunc:`free`, it needs a +strategy to avoid memory leaks as well as the use of freed memory. The chosen +method is called :dfn:`reference counting`. The principle is simple: every +object contains a counter, which is incremented when a reference to the object +is stored somewhere, and which is decremented when a reference to it is deleted. +When the counter reaches zero, the last reference to the object has been deleted +and the object is freed. + +An alternative strategy is called :dfn:`automatic garbage collection`. +(Sometimes, reference counting is also referred to as a garbage collection +strategy, hence my use of "automatic" to distinguish the two.) The big +advantage of automatic garbage collection is that the user doesn't need to call +:cfunc:`free` explicitly. (Another claimed advantage is an improvement in speed +or memory usage --- this is no hard fact however.) The disadvantage is that for +C, there is no truly portable automatic garbage collector, while reference +counting can be implemented portably (as long as the functions :cfunc:`malloc` +and :cfunc:`free` are available --- which the C Standard guarantees). Maybe some +day a sufficiently portable automatic garbage collector will be available for C. +Until then, we'll have to live with reference counts. + +While Python uses the traditional reference counting implementation, it also +offers a cycle detector that works to detect reference cycles. This allows +applications to not worry about creating direct or indirect circular references; +these are the weakness of garbage collection implemented using only reference +counting. Reference cycles consist of objects which contain (possibly indirect) +references to themselves, so that each object in the cycle has a reference count +which is non-zero. Typical reference counting implementations are not able to +reclaim the memory belonging to any objects in a reference cycle, or referenced +from the objects in the cycle, even though there are no further references to +the cycle itself. + +The cycle detector is able to detect garbage cycles and can reclaim them so long +as there are no finalizers implemented in Python (:meth:`__del__` methods). +When there are such finalizers, the detector exposes the cycles through the +:mod:`gc` module (specifically, the +``garbage`` variable in that module). The :mod:`gc` module also exposes a way +to run the detector (the :func:`collect` function), as well as configuration +interfaces and the ability to disable the detector at runtime. The cycle +detector is considered an optional component; though it is included by default, +it can be disabled at build time using the :option:`--without-cycle-gc` option +to the :program:`configure` script on Unix platforms (including Mac OS X) or by +removing the definition of ``WITH_CYCLE_GC`` in the :file:`pyconfig.h` header on +other platforms. If the cycle detector is disabled in this way, the :mod:`gc` +module will not be available. + + +.. _refcountsinpython: + +Reference Counting in Python +---------------------------- + +There are two macros, ``Py_INCREF(x)`` and ``Py_DECREF(x)``, which handle the +incrementing and decrementing of the reference count. :cfunc:`Py_DECREF` also +frees the object when the count reaches zero. For flexibility, it doesn't call +:cfunc:`free` directly --- rather, it makes a call through a function pointer in +the object's :dfn:`type object`. For this purpose (and others), every object +also contains a pointer to its type object. + +The big question now remains: when to use ``Py_INCREF(x)`` and ``Py_DECREF(x)``? +Let's first introduce some terms. Nobody "owns" an object; however, you can +:dfn:`own a reference` to an object. An object's reference count is now defined +as the number of owned references to it. The owner of a reference is +responsible for calling :cfunc:`Py_DECREF` when the reference is no longer +needed. Ownership of a reference can be transferred. There are three ways to +dispose of an owned reference: pass it on, store it, or call :cfunc:`Py_DECREF`. +Forgetting to dispose of an owned reference creates a memory leak. + +It is also possible to :dfn:`borrow` [#]_ a reference to an object. The +borrower of a reference should not call :cfunc:`Py_DECREF`. The borrower must +not hold on to the object longer than the owner from which it was borrowed. +Using a borrowed reference after the owner has disposed of it risks using freed +memory and should be avoided completely. [#]_ + +The advantage of borrowing over owning a reference is that you don't need to +take care of disposing of the reference on all possible paths through the code +--- in other words, with a borrowed reference you don't run the risk of leaking +when a premature exit is taken. The disadvantage of borrowing over leaking is +that there are some subtle situations where in seemingly correct code a borrowed +reference can be used after the owner from which it was borrowed has in fact +disposed of it. + +A borrowed reference can be changed into an owned reference by calling +:cfunc:`Py_INCREF`. This does not affect the status of the owner from which the +reference was borrowed --- it creates a new owned reference, and gives full +owner responsibilities (the new owner must dispose of the reference properly, as +well as the previous owner). + + +.. _ownershiprules: + +Ownership Rules +--------------- + +Whenever an object reference is passed into or out of a function, it is part of +the function's interface specification whether ownership is transferred with the +reference or not. + +Most functions that return a reference to an object pass on ownership with the +reference. In particular, all functions whose function it is to create a new +object, such as :cfunc:`PyInt_FromLong` and :cfunc:`Py_BuildValue`, pass +ownership to the receiver. Even if the object is not actually new, you still +receive ownership of a new reference to that object. For instance, +:cfunc:`PyInt_FromLong` maintains a cache of popular values and can return a +reference to a cached item. + +Many functions that extract objects from other objects also transfer ownership +with the reference, for instance :cfunc:`PyObject_GetAttrString`. The picture +is less clear, here, however, since a few common routines are exceptions: +:cfunc:`PyTuple_GetItem`, :cfunc:`PyList_GetItem`, :cfunc:`PyDict_GetItem`, and +:cfunc:`PyDict_GetItemString` all return references that you borrow from the +tuple, list or dictionary. + +The function :cfunc:`PyImport_AddModule` also returns a borrowed reference, even +though it may actually create the object it returns: this is possible because an +owned reference to the object is stored in ``sys.modules``. + +When you pass an object reference into another function, in general, the +function borrows the reference from you --- if it needs to store it, it will use +:cfunc:`Py_INCREF` to become an independent owner. There are exactly two +important exceptions to this rule: :cfunc:`PyTuple_SetItem` and +:cfunc:`PyList_SetItem`. These functions take over ownership of the item passed +to them --- even if they fail! (Note that :cfunc:`PyDict_SetItem` and friends +don't take over ownership --- they are "normal.") + +When a C function is called from Python, it borrows references to its arguments +from the caller. The caller owns a reference to the object, so the borrowed +reference's lifetime is guaranteed until the function returns. Only when such a +borrowed reference must be stored or passed on, it must be turned into an owned +reference by calling :cfunc:`Py_INCREF`. + +The object reference returned from a C function that is called from Python must +be an owned reference --- ownership is transferred from the function to its +caller. + + +.. _thinice: + +Thin Ice +-------- + +There are a few situations where seemingly harmless use of a borrowed reference +can lead to problems. These all have to do with implicit invocations of the +interpreter, which can cause the owner of a reference to dispose of it. + +The first and most important case to know about is using :cfunc:`Py_DECREF` on +an unrelated object while borrowing a reference to a list item. For instance:: + + void + bug(PyObject *list) + { + PyObject *item = PyList_GetItem(list, 0); + + PyList_SetItem(list, 1, PyInt_FromLong(0L)); + PyObject_Print(item, stdout, 0); /* BUG! */ + } + +This function first borrows a reference to ``list[0]``, then replaces +``list[1]`` with the value ``0``, and finally prints the borrowed reference. +Looks harmless, right? But it's not! + +Let's follow the control flow into :cfunc:`PyList_SetItem`. The list owns +references to all its items, so when item 1 is replaced, it has to dispose of +the original item 1. Now let's suppose the original item 1 was an instance of a +user-defined class, and let's further suppose that the class defined a +:meth:`__del__` method. If this class instance has a reference count of 1, +disposing of it will call its :meth:`__del__` method. + +Since it is written in Python, the :meth:`__del__` method can execute arbitrary +Python code. Could it perhaps do something to invalidate the reference to +``item`` in :cfunc:`bug`? You bet! Assuming that the list passed into +:cfunc:`bug` is accessible to the :meth:`__del__` method, it could execute a +statement to the effect of ``del list[0]``, and assuming this was the last +reference to that object, it would free the memory associated with it, thereby +invalidating ``item``. + +The solution, once you know the source of the problem, is easy: temporarily +increment the reference count. The correct version of the function reads:: + + void + no_bug(PyObject *list) + { + PyObject *item = PyList_GetItem(list, 0); + + Py_INCREF(item); + PyList_SetItem(list, 1, PyInt_FromLong(0L)); + PyObject_Print(item, stdout, 0); + Py_DECREF(item); + } + +This is a true story. An older version of Python contained variants of this bug +and someone spent a considerable amount of time in a C debugger to figure out +why his :meth:`__del__` methods would fail... + +The second case of problems with a borrowed reference is a variant involving +threads. Normally, multiple threads in the Python interpreter can't get in each +other's way, because there is a global lock protecting Python's entire object +space. However, it is possible to temporarily release this lock using the macro +:cmacro:`Py_BEGIN_ALLOW_THREADS`, and to re-acquire it using +:cmacro:`Py_END_ALLOW_THREADS`. This is common around blocking I/O calls, to +let other threads use the processor while waiting for the I/O to complete. +Obviously, the following function has the same problem as the previous one:: + + void + bug(PyObject *list) + { + PyObject *item = PyList_GetItem(list, 0); + Py_BEGIN_ALLOW_THREADS + ...some blocking I/O call... + Py_END_ALLOW_THREADS + PyObject_Print(item, stdout, 0); /* BUG! */ + } + + +.. _nullpointers: + +NULL Pointers +------------- + +In general, functions that take object references as arguments do not expect you +to pass them *NULL* pointers, and will dump core (or cause later core dumps) if +you do so. Functions that return object references generally return *NULL* only +to indicate that an exception occurred. The reason for not testing for *NULL* +arguments is that functions often pass the objects they receive on to other +function --- if each function were to test for *NULL*, there would be a lot of +redundant tests and the code would run more slowly. + +It is better to test for *NULL* only at the "source:" when a pointer that may be +*NULL* is received, for example, from :cfunc:`malloc` or from a function that +may raise an exception. + +The macros :cfunc:`Py_INCREF` and :cfunc:`Py_DECREF` do not check for *NULL* +pointers --- however, their variants :cfunc:`Py_XINCREF` and :cfunc:`Py_XDECREF` +do. + +The macros for checking for a particular object type (``Pytype_Check()``) don't +check for *NULL* pointers --- again, there is much code that calls several of +these in a row to test an object against various different expected types, and +this would generate redundant tests. There are no variants with *NULL* +checking. + +The C function calling mechanism guarantees that the argument list passed to C +functions (``args`` in the examples) is never *NULL* --- in fact it guarantees +that it is always a tuple. [#]_ + +It is a severe error to ever let a *NULL* pointer "escape" to the Python user. + +.. % Frank Stajano: +.. % A pedagogically buggy example, along the lines of the previous listing, +.. % would be helpful here -- showing in more concrete terms what sort of +.. % actions could cause the problem. I can't very well imagine it from the +.. % description. + + +.. _cplusplus: + +Writing Extensions in C++ +========================= + +It is possible to write extension modules in C++. Some restrictions apply. If +the main program (the Python interpreter) is compiled and linked by the C +compiler, global or static objects with constructors cannot be used. This is +not a problem if the main program is linked by the C++ compiler. Functions that +will be called by the Python interpreter (in particular, module initialization +functions) have to be declared using ``extern "C"``. It is unnecessary to +enclose the Python header files in ``extern "C" {...}`` --- they use this form +already if the symbol ``__cplusplus`` is defined (all recent C++ compilers +define this symbol). + + +.. _using-cobjects: + +Providing a C API for an Extension Module +========================================= + +.. sectionauthor:: Konrad Hinsen + + +Many extension modules just provide new functions and types to be used from +Python, but sometimes the code in an extension module can be useful for other +extension modules. For example, an extension module could implement a type +"collection" which works like lists without order. Just like the standard Python +list type has a C API which permits extension modules to create and manipulate +lists, this new collection type should have a set of C functions for direct +manipulation from other extension modules. + +At first sight this seems easy: just write the functions (without declaring them +:keyword:`static`, of course), provide an appropriate header file, and document +the C API. And in fact this would work if all extension modules were always +linked statically with the Python interpreter. When modules are used as shared +libraries, however, the symbols defined in one module may not be visible to +another module. The details of visibility depend on the operating system; some +systems use one global namespace for the Python interpreter and all extension +modules (Windows, for example), whereas others require an explicit list of +imported symbols at module link time (AIX is one example), or offer a choice of +different strategies (most Unices). And even if symbols are globally visible, +the module whose functions one wishes to call might not have been loaded yet! + +Portability therefore requires not to make any assumptions about symbol +visibility. This means that all symbols in extension modules should be declared +:keyword:`static`, except for the module's initialization function, in order to +avoid name clashes with other extension modules (as discussed in section +:ref:`methodtable`). And it means that symbols that *should* be accessible from +other extension modules must be exported in a different way. + +Python provides a special mechanism to pass C-level information (pointers) from +one extension module to another one: CObjects. A CObject is a Python data type +which stores a pointer (:ctype:`void \*`). CObjects can only be created and +accessed via their C API, but they can be passed around like any other Python +object. In particular, they can be assigned to a name in an extension module's +namespace. Other extension modules can then import this module, retrieve the +value of this name, and then retrieve the pointer from the CObject. + +There are many ways in which CObjects can be used to export the C API of an +extension module. Each name could get its own CObject, or all C API pointers +could be stored in an array whose address is published in a CObject. And the +various tasks of storing and retrieving the pointers can be distributed in +different ways between the module providing the code and the client modules. + +The following example demonstrates an approach that puts most of the burden on +the writer of the exporting module, which is appropriate for commonly used +library modules. It stores all C API pointers (just one in the example!) in an +array of :ctype:`void` pointers which becomes the value of a CObject. The header +file corresponding to the module provides a macro that takes care of importing +the module and retrieving its C API pointers; client modules only have to call +this macro before accessing the C API. + +The exporting module is a modification of the :mod:`spam` module from section +:ref:`extending-simpleexample`. The function :func:`spam.system` does not call +the C library function :cfunc:`system` directly, but a function +:cfunc:`PySpam_System`, which would of course do something more complicated in +reality (such as adding "spam" to every command). This function +:cfunc:`PySpam_System` is also exported to other extension modules. + +The function :cfunc:`PySpam_System` is a plain C function, declared +:keyword:`static` like everything else:: + + static int + PySpam_System(const char *command) + { + return system(command); + } + +The function :cfunc:`spam_system` is modified in a trivial way:: + + static PyObject * + spam_system(PyObject *self, PyObject *args) + { + const char *command; + int sts; + + if (!PyArg_ParseTuple(args, "s", &command)) + return NULL; + sts = PySpam_System(command); + return Py_BuildValue("i", sts); + } + +In the beginning of the module, right after the line :: + + #include "Python.h" + +two more lines must be added:: + + #define SPAM_MODULE + #include "spammodule.h" + +The ``#define`` is used to tell the header file that it is being included in the +exporting module, not a client module. Finally, the module's initialization +function must take care of initializing the C API pointer array:: + + PyMODINIT_FUNC + initspam(void) + { + PyObject *m; + static void *PySpam_API[PySpam_API_pointers]; + PyObject *c_api_object; + + m = Py_InitModule("spam", SpamMethods); + if (m == NULL) + return; + + /* Initialize the C API pointer array */ + PySpam_API[PySpam_System_NUM] = (void *)PySpam_System; + + /* Create a CObject containing the API pointer array's address */ + c_api_object = PyCObject_FromVoidPtr((void *)PySpam_API, NULL); + + if (c_api_object != NULL) + PyModule_AddObject(m, "_C_API", c_api_object); + } + +Note that ``PySpam_API`` is declared :keyword:`static`; otherwise the pointer +array would disappear when :func:`initspam` terminates! + +The bulk of the work is in the header file :file:`spammodule.h`, which looks +like this:: + + #ifndef Py_SPAMMODULE_H + #define Py_SPAMMODULE_H + #ifdef __cplusplus + extern "C" { + #endif + + /* Header file for spammodule */ + + /* C API functions */ + #define PySpam_System_NUM 0 + #define PySpam_System_RETURN int + #define PySpam_System_PROTO (const char *command) + + /* Total number of C API pointers */ + #define PySpam_API_pointers 1 + + + #ifdef SPAM_MODULE + /* This section is used when compiling spammodule.c */ + + static PySpam_System_RETURN PySpam_System PySpam_System_PROTO; + + #else + /* This section is used in modules that use spammodule's API */ + + static void **PySpam_API; + + #define PySpam_System \ + (*(PySpam_System_RETURN (*)PySpam_System_PROTO) PySpam_API[PySpam_System_NUM]) + + /* Return -1 and set exception on error, 0 on success. */ + static int + import_spam(void) + { + PyObject *module = PyImport_ImportModule("spam"); + + if (module != NULL) { + PyObject *c_api_object = PyObject_GetAttrString(module, "_C_API"); + if (c_api_object == NULL) + return -1; + if (PyCObject_Check(c_api_object)) + PySpam_API = (void **)PyCObject_AsVoidPtr(c_api_object); + Py_DECREF(c_api_object); + } + return 0; + } + + #endif + + #ifdef __cplusplus + } + #endif + + #endif /* !defined(Py_SPAMMODULE_H) */ + +All that a client module must do in order to have access to the function +:cfunc:`PySpam_System` is to call the function (or rather macro) +:cfunc:`import_spam` in its initialization function:: + + PyMODINIT_FUNC + initclient(void) + { + PyObject *m; + + m = Py_InitModule("client", ClientMethods); + if (m == NULL) + return; + if (import_spam() < 0) + return; + /* additional initialization can happen here */ + } + +The main disadvantage of this approach is that the file :file:`spammodule.h` is +rather complicated. However, the basic structure is the same for each function +that is exported, so it has to be learned only once. + +Finally it should be mentioned that CObjects offer additional functionality, +which is especially useful for memory allocation and deallocation of the pointer +stored in a CObject. The details are described in the Python/C API Reference +Manual in the section :ref:`cobjects` and in the implementation of CObjects (files +:file:`Include/cobject.h` and :file:`Objects/cobject.c` in the Python source +code distribution). + +.. rubric:: Footnotes + +.. [#] An interface for this function already exists in the standard module :mod:`os` + --- it was chosen as a simple and straightforward example. + +.. [#] The metaphor of "borrowing" a reference is not completely correct: the owner + still has a copy of the reference. + +.. [#] Checking that the reference count is at least 1 **does not work** --- the + reference count itself could be in freed memory and may thus be reused for + another object! + +.. [#] These guarantees don't hold when you use the "old" style calling convention --- + this is still found in much existing code. + diff --git a/Doc/extending/index.rst b/Doc/extending/index.rst new file mode 100644 index 0000000..6e8cf79 --- /dev/null +++ b/Doc/extending/index.rst @@ -0,0 +1,34 @@ +.. _extending-index: + +################################################## + Extending and Embedding the Python Interpreter +################################################## + +:Release: |version| +:Date: |today| + +This document describes how to write modules in C or C++ to extend the Python +interpreter with new modules. Those modules can define new functions but also +new object types and their methods. The document also describes how to embed +the Python interpreter in another application, for use as an extension language. +Finally, it shows how to compile and link extension modules so that they can be +loaded dynamically (at run time) into the interpreter, if the underlying +operating system supports this feature. + +This document assumes basic knowledge about Python. For an informal +introduction to the language, see :ref:`tutorial-index`. :ref:`reference-index` +gives a more formal definition of the language. :ref:`library-index` documents +the existing object types, functions and modules (both built-in and written in +Python) that give the language its wide application range. + +For a detailed description of the whole Python/C API, see the separate +:ref:`c-api-index`. + +.. toctree:: + :maxdepth: 2 + + extending.rst + newtypes.rst + building.rst + windows.rst + embedding.rst diff --git a/Doc/extending/newtypes.rst b/Doc/extending/newtypes.rst new file mode 100644 index 0000000..72aaf1b --- /dev/null +++ b/Doc/extending/newtypes.rst @@ -0,0 +1,1580 @@ +.. highlightlang:: c + + +.. _defining-new-types: + +****************** +Defining New Types +****************** + +.. sectionauthor:: Michael Hudson +.. sectionauthor:: Dave Kuhlman +.. sectionauthor:: Jim Fulton + + +As mentioned in the last chapter, Python allows the writer of an extension +module to define new types that can be manipulated from Python code, much like +strings and lists in core Python. + +This is not hard; the code for all extension types follows a pattern, but there +are some details that you need to understand before you can get started. + +.. note:: + + The way new types are defined changed dramatically (and for the better) in + Python 2.2. This document documents how to define new types for Python 2.2 and + later. If you need to support older versions of Python, you will need to refer + to `older versions of this documentation + `_. + + +.. _dnt-basics: + +The Basics +========== + +The Python runtime sees all Python objects as variables of type +:ctype:`PyObject\*`. A :ctype:`PyObject` is not a very magnificent object - it +just contains the refcount and a pointer to the object's "type object". This is +where the action is; the type object determines which (C) functions get called +when, for instance, an attribute gets looked up on an object or it is multiplied +by another object. These C functions are called "type methods" to distinguish +them from things like ``[].append`` (which we call "object methods"). + +So, if you want to define a new object type, you need to create a new type +object. + +This sort of thing can only be explained by example, so here's a minimal, but +complete, module that defines a new type: + +.. literalinclude:: ../includes/noddy.c + + +Now that's quite a bit to take in at once, but hopefully bits will seem familiar +from the last chapter. + +The first bit that will be new is:: + + typedef struct { + PyObject_HEAD + } noddy_NoddyObject; + +This is what a Noddy object will contain---in this case, nothing more than every +Python object contains, namely a refcount and a pointer to a type object. These +are the fields the ``PyObject_HEAD`` macro brings in. The reason for the macro +is to standardize the layout and to enable special debugging fields in debug +builds. Note that there is no semicolon after the ``PyObject_HEAD`` macro; one +is included in the macro definition. Be wary of adding one by accident; it's +easy to do from habit, and your compiler might not complain, but someone else's +probably will! (On Windows, MSVC is known to call this an error and refuse to +compile the code.) + +For contrast, let's take a look at the corresponding definition for standard +Python integers:: + + typedef struct { + PyObject_HEAD + long ob_ival; + } PyIntObject; + +Moving on, we come to the crunch --- the type object. :: + + static PyTypeObject noddy_NoddyType = { + PyObject_HEAD_INIT(NULL) + 0, /*ob_size*/ + "noddy.Noddy", /*tp_name*/ + sizeof(noddy_NoddyObject), /*tp_basicsize*/ + 0, /*tp_itemsize*/ + 0, /*tp_dealloc*/ + 0, /*tp_print*/ + 0, /*tp_getattr*/ + 0, /*tp_setattr*/ + 0, /*tp_compare*/ + 0, /*tp_repr*/ + 0, /*tp_as_number*/ + 0, /*tp_as_sequence*/ + 0, /*tp_as_mapping*/ + 0, /*tp_hash */ + 0, /*tp_call*/ + 0, /*tp_str*/ + 0, /*tp_getattro*/ + 0, /*tp_setattro*/ + 0, /*tp_as_buffer*/ + Py_TPFLAGS_DEFAULT, /*tp_flags*/ + "Noddy objects", /* tp_doc */ + }; + +Now if you go and look up the definition of :ctype:`PyTypeObject` in +:file:`object.h` you'll see that it has many more fields that the definition +above. The remaining fields will be filled with zeros by the C compiler, and +it's common practice to not specify them explicitly unless you need them. + +This is so important that we're going to pick the top of it apart still +further:: + + PyObject_HEAD_INIT(NULL) + +This line is a bit of a wart; what we'd like to write is:: + + PyObject_HEAD_INIT(&PyType_Type) + +as the type of a type object is "type", but this isn't strictly conforming C and +some compilers complain. Fortunately, this member will be filled in for us by +:cfunc:`PyType_Ready`. :: + + 0, /* ob_size */ + +The :attr:`ob_size` field of the header is not used; its presence in the type +structure is a historical artifact that is maintained for binary compatibility +with extension modules compiled for older versions of Python. Always set this +field to zero. :: + + "noddy.Noddy", /* tp_name */ + +The name of our type. This will appear in the default textual representation of +our objects and in some error messages, for example:: + + >>> "" + noddy.new_noddy() + Traceback (most recent call last): + File "", line 1, in ? + TypeError: cannot add type "noddy.Noddy" to string + +Note that the name is a dotted name that includes both the module name and the +name of the type within the module. The module in this case is :mod:`noddy` and +the type is :class:`Noddy`, so we set the type name to :class:`noddy.Noddy`. :: + + sizeof(noddy_NoddyObject), /* tp_basicsize */ + +This is so that Python knows how much memory to allocate when you call +:cfunc:`PyObject_New`. + +.. note:: + + If you want your type to be subclassable from Python, and your type has the same + :attr:`tp_basicsize` as its base type, you may have problems with multiple + inheritance. A Python subclass of your type will have to list your type first + in its :attr:`__bases__`, or else it will not be able to call your type's + :meth:`__new__` method without getting an error. You can avoid this problem by + ensuring that your type has a larger value for :attr:`tp_basicsize` than its + base type does. Most of the time, this will be true anyway, because either your + base type will be :class:`object`, or else you will be adding data members to + your base type, and therefore increasing its size. + +:: + + 0, /* tp_itemsize */ + +This has to do with variable length objects like lists and strings. Ignore this +for now. + +Skipping a number of type methods that we don't provide, we set the class flags +to :const:`Py_TPFLAGS_DEFAULT`. :: + + Py_TPFLAGS_DEFAULT, /*tp_flags*/ + +All types should include this constant in their flags. It enables all of the +members defined by the current version of Python. + +We provide a doc string for the type in :attr:`tp_doc`. :: + + "Noddy objects", /* tp_doc */ + +Now we get into the type methods, the things that make your objects different +from the others. We aren't going to implement any of these in this version of +the module. We'll expand this example later to have more interesting behavior. + +For now, all we want to be able to do is to create new :class:`Noddy` objects. +To enable object creation, we have to provide a :attr:`tp_new` implementation. +In this case, we can just use the default implementation provided by the API +function :cfunc:`PyType_GenericNew`. We'd like to just assign this to the +:attr:`tp_new` slot, but we can't, for portability sake, On some platforms or +compilers, we can't statically initialize a structure member with a function +defined in another C module, so, instead, we'll assign the :attr:`tp_new` slot +in the module initialization function just before calling +:cfunc:`PyType_Ready`:: + + noddy_NoddyType.tp_new = PyType_GenericNew; + if (PyType_Ready(&noddy_NoddyType) < 0) + return; + +All the other type methods are *NULL*, so we'll go over them later --- that's +for a later section! + +Everything else in the file should be familiar, except for some code in +:cfunc:`initnoddy`:: + + if (PyType_Ready(&noddy_NoddyType) < 0) + return; + +This initializes the :class:`Noddy` type, filing in a number of members, +including :attr:`ob_type` that we initially set to *NULL*. :: + + PyModule_AddObject(m, "Noddy", (PyObject *)&noddy_NoddyType); + +This adds the type to the module dictionary. This allows us to create +:class:`Noddy` instances by calling the :class:`Noddy` class:: + + >>> import noddy + >>> mynoddy = noddy.Noddy() + +That's it! All that remains is to build it; put the above code in a file called +:file:`noddy.c` and :: + + from distutils.core import setup, Extension + setup(name="noddy", version="1.0", + ext_modules=[Extension("noddy", ["noddy.c"])]) + +in a file called :file:`setup.py`; then typing :: + + $ python setup.py build + +at a shell should produce a file :file:`noddy.so` in a subdirectory; move to +that directory and fire up Python --- you should be able to ``import noddy`` and +play around with Noddy objects. + +.. % $ <-- bow to font-lock ;-( + +That wasn't so hard, was it? + +Of course, the current Noddy type is pretty uninteresting. It has no data and +doesn't do anything. It can't even be subclassed. + + +Adding data and methods to the Basic example +-------------------------------------------- + +Let's expend the basic example to add some data and methods. Let's also make +the type usable as a base class. We'll create a new module, :mod:`noddy2` that +adds these capabilities: + +.. literalinclude:: ../includes/noddy2.c + + +This version of the module has a number of changes. + +We've added an extra include:: + + #include "structmember.h" + +This include provides declarations that we use to handle attributes, as +described a bit later. + +The name of the :class:`Noddy` object structure has been shortened to +:class:`Noddy`. The type object name has been shortened to :class:`NoddyType`. + +The :class:`Noddy` type now has three data attributes, *first*, *last*, and +*number*. The *first* and *last* variables are Python strings containing first +and last names. The *number* attribute is an integer. + +The object structure is updated accordingly:: + + typedef struct { + PyObject_HEAD + PyObject *first; + PyObject *last; + int number; + } Noddy; + +Because we now have data to manage, we have to be more careful about object +allocation and deallocation. At a minimum, we need a deallocation method:: + + static void + Noddy_dealloc(Noddy* self) + { + Py_XDECREF(self->first); + Py_XDECREF(self->last); + self->ob_type->tp_free((PyObject*)self); + } + +which is assigned to the :attr:`tp_dealloc` member:: + + (destructor)Noddy_dealloc, /*tp_dealloc*/ + +This method decrements the reference counts of the two Python attributes. We use +:cfunc:`Py_XDECREF` here because the :attr:`first` and :attr:`last` members +could be *NULL*. It then calls the :attr:`tp_free` member of the object's type +to free the object's memory. Note that the object's type might not be +:class:`NoddyType`, because the object may be an instance of a subclass. + +We want to make sure that the first and last names are initialized to empty +strings, so we provide a new method:: + + static PyObject * + Noddy_new(PyTypeObject *type, PyObject *args, PyObject *kwds) + { + Noddy *self; + + self = (Noddy *)type->tp_alloc(type, 0); + if (self != NULL) { + self->first = PyString_FromString(""); + if (self->first == NULL) + { + Py_DECREF(self); + return NULL; + } + + self->last = PyString_FromString(""); + if (self->last == NULL) + { + Py_DECREF(self); + return NULL; + } + + self->number = 0; + } + + return (PyObject *)self; + } + +and install it in the :attr:`tp_new` member:: + + Noddy_new, /* tp_new */ + +The new member is responsible for creating (as opposed to initializing) objects +of the type. It is exposed in Python as the :meth:`__new__` method. See the +paper titled "Unifying types and classes in Python" for a detailed discussion of +the :meth:`__new__` method. One reason to implement a new method is to assure +the initial values of instance variables. In this case, we use the new method +to make sure that the initial values of the members :attr:`first` and +:attr:`last` are not *NULL*. If we didn't care whether the initial values were +*NULL*, we could have used :cfunc:`PyType_GenericNew` as our new method, as we +did before. :cfunc:`PyType_GenericNew` initializes all of the instance variable +members to *NULL*. + +The new method is a static method that is passed the type being instantiated and +any arguments passed when the type was called, and that returns the new object +created. New methods always accept positional and keyword arguments, but they +often ignore the arguments, leaving the argument handling to initializer +methods. Note that if the type supports subclassing, the type passed may not be +the type being defined. The new method calls the tp_alloc slot to allocate +memory. We don't fill the :attr:`tp_alloc` slot ourselves. Rather +:cfunc:`PyType_Ready` fills it for us by inheriting it from our base class, +which is :class:`object` by default. Most types use the default allocation. + +.. note:: + + If you are creating a co-operative :attr:`tp_new` (one that calls a base type's + :attr:`tp_new` or :meth:`__new__`), you must *not* try to determine what method + to call using method resolution order at runtime. Always statically determine + what type you are going to call, and call its :attr:`tp_new` directly, or via + ``type->tp_base->tp_new``. If you do not do this, Python subclasses of your + type that also inherit from other Python-defined classes may not work correctly. + (Specifically, you may not be able to create instances of such subclasses + without getting a :exc:`TypeError`.) + +We provide an initialization function:: + + static int + Noddy_init(Noddy *self, PyObject *args, PyObject *kwds) + { + PyObject *first=NULL, *last=NULL, *tmp; + + static char *kwlist[] = {"first", "last", "number", NULL}; + + if (! PyArg_ParseTupleAndKeywords(args, kwds, "|OOi", kwlist, + &first, &last, + &self->number)) + return -1; + + if (first) { + tmp = self->first; + Py_INCREF(first); + self->first = first; + Py_XDECREF(tmp); + } + + if (last) { + tmp = self->last; + Py_INCREF(last); + self->last = last; + Py_XDECREF(tmp); + } + + return 0; + } + +by filling the :attr:`tp_init` slot. :: + + (initproc)Noddy_init, /* tp_init */ + +The :attr:`tp_init` slot is exposed in Python as the :meth:`__init__` method. It +is used to initialize an object after it's created. Unlike the new method, we +can't guarantee that the initializer is called. The initializer isn't called +when unpickling objects and it can be overridden. Our initializer accepts +arguments to provide initial values for our instance. Initializers always accept +positional and keyword arguments. + +Initializers can be called multiple times. Anyone can call the :meth:`__init__` +method on our objects. For this reason, we have to be extra careful when +assigning the new values. We might be tempted, for example to assign the +:attr:`first` member like this:: + + if (first) { + Py_XDECREF(self->first); + Py_INCREF(first); + self->first = first; + } + +But this would be risky. Our type doesn't restrict the type of the +:attr:`first` member, so it could be any kind of object. It could have a +destructor that causes code to be executed that tries to access the +:attr:`first` member. To be paranoid and protect ourselves against this +possibility, we almost always reassign members before decrementing their +reference counts. When don't we have to do this? + +* when we absolutely know that the reference count is greater than 1 + +* when we know that deallocation of the object [#]_ will not cause any calls + back into our type's code + +* when decrementing a reference count in a :attr:`tp_dealloc` handler when + garbage-collections is not supported [#]_ + +We want to want to expose our instance variables as attributes. There are a +number of ways to do that. The simplest way is to define member definitions:: + + static PyMemberDef Noddy_members[] = { + {"first", T_OBJECT_EX, offsetof(Noddy, first), 0, + "first name"}, + {"last", T_OBJECT_EX, offsetof(Noddy, last), 0, + "last name"}, + {"number", T_INT, offsetof(Noddy, number), 0, + "noddy number"}, + {NULL} /* Sentinel */ + }; + +and put the definitions in the :attr:`tp_members` slot:: + + Noddy_members, /* tp_members */ + +Each member definition has a member name, type, offset, access flags and +documentation string. See the "Generic Attribute Management" section below for +details. + +A disadvantage of this approach is that it doesn't provide a way to restrict the +types of objects that can be assigned to the Python attributes. We expect the +first and last names to be strings, but any Python objects can be assigned. +Further, the attributes can be deleted, setting the C pointers to *NULL*. Even +though we can make sure the members are initialized to non-*NULL* values, the +members can be set to *NULL* if the attributes are deleted. + +We define a single method, :meth:`name`, that outputs the objects name as the +concatenation of the first and last names. :: + + static PyObject * + Noddy_name(Noddy* self) + { + static PyObject *format = NULL; + PyObject *args, *result; + + if (format == NULL) { + format = PyString_FromString("%s %s"); + if (format == NULL) + return NULL; + } + + if (self->first == NULL) { + PyErr_SetString(PyExc_AttributeError, "first"); + return NULL; + } + + if (self->last == NULL) { + PyErr_SetString(PyExc_AttributeError, "last"); + return NULL; + } + + args = Py_BuildValue("OO", self->first, self->last); + if (args == NULL) + return NULL; + + result = PyString_Format(format, args); + Py_DECREF(args); + + return result; + } + +The method is implemented as a C function that takes a :class:`Noddy` (or +:class:`Noddy` subclass) instance as the first argument. Methods always take an +instance as the first argument. Methods often take positional and keyword +arguments as well, but in this cased we don't take any and don't need to accept +a positional argument tuple or keyword argument dictionary. This method is +equivalent to the Python method:: + + def name(self): + return "%s %s" % (self.first, self.last) + +Note that we have to check for the possibility that our :attr:`first` and +:attr:`last` members are *NULL*. This is because they can be deleted, in which +case they are set to *NULL*. It would be better to prevent deletion of these +attributes and to restrict the attribute values to be strings. We'll see how to +do that in the next section. + +Now that we've defined the method, we need to create an array of method +definitions:: + + static PyMethodDef Noddy_methods[] = { + {"name", (PyCFunction)Noddy_name, METH_NOARGS, + "Return the name, combining the first and last name" + }, + {NULL} /* Sentinel */ + }; + +and assign them to the :attr:`tp_methods` slot:: + + Noddy_methods, /* tp_methods */ + +Note that we used the :const:`METH_NOARGS` flag to indicate that the method is +passed no arguments. + +Finally, we'll make our type usable as a base class. We've written our methods +carefully so far so that they don't make any assumptions about the type of the +object being created or used, so all we need to do is to add the +:const:`Py_TPFLAGS_BASETYPE` to our class flag definition:: + + Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ + +We rename :cfunc:`initnoddy` to :cfunc:`initnoddy2` and update the module name +passed to :cfunc:`Py_InitModule3`. + +Finally, we update our :file:`setup.py` file to build the new module:: + + from distutils.core import setup, Extension + setup(name="noddy", version="1.0", + ext_modules=[ + Extension("noddy", ["noddy.c"]), + Extension("noddy2", ["noddy2.c"]), + ]) + + +Providing finer control over data attributes +-------------------------------------------- + +In this section, we'll provide finer control over how the :attr:`first` and +:attr:`last` attributes are set in the :class:`Noddy` example. In the previous +version of our module, the instance variables :attr:`first` and :attr:`last` +could be set to non-string values or even deleted. We want to make sure that +these attributes always contain strings. + +.. literalinclude:: ../includes/noddy3.c + + +To provide greater control, over the :attr:`first` and :attr:`last` attributes, +we'll use custom getter and setter functions. Here are the functions for +getting and setting the :attr:`first` attribute:: + + Noddy_getfirst(Noddy *self, void *closure) + { + Py_INCREF(self->first); + return self->first; + } + + static int + Noddy_setfirst(Noddy *self, PyObject *value, void *closure) + { + if (value == NULL) { + PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute"); + return -1; + } + + if (! PyString_Check(value)) { + PyErr_SetString(PyExc_TypeError, + "The first attribute value must be a string"); + return -1; + } + + Py_DECREF(self->first); + Py_INCREF(value); + self->first = value; + + return 0; + } + +The getter function is passed a :class:`Noddy` object and a "closure", which is +void pointer. In this case, the closure is ignored. (The closure supports an +advanced usage in which definition data is passed to the getter and setter. This +could, for example, be used to allow a single set of getter and setter functions +that decide the attribute to get or set based on data in the closure.) + +The setter function is passed the :class:`Noddy` object, the new value, and the +closure. The new value may be *NULL*, in which case the attribute is being +deleted. In our setter, we raise an error if the attribute is deleted or if the +attribute value is not a string. + +We create an array of :ctype:`PyGetSetDef` structures:: + + static PyGetSetDef Noddy_getseters[] = { + {"first", + (getter)Noddy_getfirst, (setter)Noddy_setfirst, + "first name", + NULL}, + {"last", + (getter)Noddy_getlast, (setter)Noddy_setlast, + "last name", + NULL}, + {NULL} /* Sentinel */ + }; + +and register it in the :attr:`tp_getset` slot:: + + Noddy_getseters, /* tp_getset */ + +to register out attribute getters and setters. + +The last item in a :ctype:`PyGetSetDef` structure is the closure mentioned +above. In this case, we aren't using the closure, so we just pass *NULL*. + +We also remove the member definitions for these attributes:: + + static PyMemberDef Noddy_members[] = { + {"number", T_INT, offsetof(Noddy, number), 0, + "noddy number"}, + {NULL} /* Sentinel */ + }; + +We also need to update the :attr:`tp_init` handler to only allow strings [#]_ to +be passed:: + + static int + Noddy_init(Noddy *self, PyObject *args, PyObject *kwds) + { + PyObject *first=NULL, *last=NULL, *tmp; + + static char *kwlist[] = {"first", "last", "number", NULL}; + + if (! PyArg_ParseTupleAndKeywords(args, kwds, "|SSi", kwlist, + &first, &last, + &self->number)) + return -1; + + if (first) { + tmp = self->first; + Py_INCREF(first); + self->first = first; + Py_DECREF(tmp); + } + + if (last) { + tmp = self->last; + Py_INCREF(last); + self->last = last; + Py_DECREF(tmp); + } + + return 0; + } + +With these changes, we can assure that the :attr:`first` and :attr:`last` +members are never *NULL* so we can remove checks for *NULL* values in almost all +cases. This means that most of the :cfunc:`Py_XDECREF` calls can be converted to +:cfunc:`Py_DECREF` calls. The only place we can't change these calls is in the +deallocator, where there is the possibility that the initialization of these +members failed in the constructor. + +We also rename the module initialization function and module name in the +initialization function, as we did before, and we add an extra definition to the +:file:`setup.py` file. + + +Supporting cyclic garbage collection +------------------------------------ + +Python has a cyclic-garbage collector that can identify unneeded objects even +when their reference counts are not zero. This can happen when objects are +involved in cycles. For example, consider:: + + >>> l = [] + >>> l.append(l) + >>> del l + +In this example, we create a list that contains itself. When we delete it, it +still has a reference from itself. Its reference count doesn't drop to zero. +Fortunately, Python's cyclic-garbage collector will eventually figure out that +the list is garbage and free it. + +In the second version of the :class:`Noddy` example, we allowed any kind of +object to be stored in the :attr:`first` or :attr:`last` attributes. [#]_ This +means that :class:`Noddy` objects can participate in cycles:: + + >>> import noddy2 + >>> n = noddy2.Noddy() + >>> l = [n] + >>> n.first = l + +This is pretty silly, but it gives us an excuse to add support for the +cyclic-garbage collector to the :class:`Noddy` example. To support cyclic +garbage collection, types need to fill two slots and set a class flag that +enables these slots: + +.. literalinclude:: ../includes/noddy4.c + + +The traversal method provides access to subobjects that could participate in +cycles:: + + static int + Noddy_traverse(Noddy *self, visitproc visit, void *arg) + { + int vret; + + if (self->first) { + vret = visit(self->first, arg); + if (vret != 0) + return vret; + } + if (self->last) { + vret = visit(self->last, arg); + if (vret != 0) + return vret; + } + + return 0; + } + +For each subobject that can participate in cycles, we need to call the +:cfunc:`visit` function, which is passed to the traversal method. The +:cfunc:`visit` function takes as arguments the subobject and the extra argument +*arg* passed to the traversal method. It returns an integer value that must be +returned if it is non-zero. + +Python 2.4 and higher provide a :cfunc:`Py_VISIT` macro that automates calling +visit functions. With :cfunc:`Py_VISIT`, :cfunc:`Noddy_traverse` can be +simplified:: + + static int + Noddy_traverse(Noddy *self, visitproc visit, void *arg) + { + Py_VISIT(self->first); + Py_VISIT(self->last); + return 0; + } + +.. note:: + + Note that the :attr:`tp_traverse` implementation must name its arguments exactly + *visit* and *arg* in order to use :cfunc:`Py_VISIT`. This is to encourage + uniformity across these boring implementations. + +We also need to provide a method for clearing any subobjects that can +participate in cycles. We implement the method and reimplement the deallocator +to use it:: + + static int + Noddy_clear(Noddy *self) + { + PyObject *tmp; + + tmp = self->first; + self->first = NULL; + Py_XDECREF(tmp); + + tmp = self->last; + self->last = NULL; + Py_XDECREF(tmp); + + return 0; + } + + static void + Noddy_dealloc(Noddy* self) + { + Noddy_clear(self); + self->ob_type->tp_free((PyObject*)self); + } + +Notice the use of a temporary variable in :cfunc:`Noddy_clear`. We use the +temporary variable so that we can set each member to *NULL* before decrementing +its reference count. We do this because, as was discussed earlier, if the +reference count drops to zero, we might cause code to run that calls back into +the object. In addition, because we now support garbage collection, we also +have to worry about code being run that triggers garbage collection. If garbage +collection is run, our :attr:`tp_traverse` handler could get called. We can't +take a chance of having :cfunc:`Noddy_traverse` called when a member's reference +count has dropped to zero and its value hasn't been set to *NULL*. + +Python 2.4 and higher provide a :cfunc:`Py_CLEAR` that automates the careful +decrementing of reference counts. With :cfunc:`Py_CLEAR`, the +:cfunc:`Noddy_clear` function can be simplified:: + + static int + Noddy_clear(Noddy *self) + { + Py_CLEAR(self->first); + Py_CLEAR(self->last); + return 0; + } + +Finally, we add the :const:`Py_TPFLAGS_HAVE_GC` flag to the class flags:: + + Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC, /*tp_flags*/ + +That's pretty much it. If we had written custom :attr:`tp_alloc` or +:attr:`tp_free` slots, we'd need to modify them for cyclic-garbage collection. +Most extensions will use the versions automatically provided. + + +Subclassing other types +----------------------- + +It is possible to create new extension types that are derived from existing +types. It is easiest to inherit from the built in types, since an extension can +easily use the :class:`PyTypeObject` it needs. It can be difficult to share +these :class:`PyTypeObject` structures between extension modules. + +In this example we will create a :class:`Shoddy` type that inherits from the +builtin :class:`list` type. The new type will be completely compatible with +regular lists, but will have an additional :meth:`increment` method that +increases an internal counter. :: + + >>> import shoddy + >>> s = shoddy.Shoddy(range(3)) + >>> s.extend(s) + >>> print len(s) + 6 + >>> print s.increment() + 1 + >>> print s.increment() + 2 + +.. literalinclude:: ../includes/shoddy.c + + +As you can see, the source code closely resembles the :class:`Noddy` examples in +previous sections. We will break down the main differences between them. :: + + typedef struct { + PyListObject list; + int state; + } Shoddy; + +The primary difference for derived type objects is that the base type's object +structure must be the first value. The base type will already include the +:cfunc:`PyObject_HEAD` at the beginning of its structure. + +When a Python object is a :class:`Shoddy` instance, its *PyObject\** pointer can +be safely cast to both *PyListObject\** and *Shoddy\**. :: + + static int + Shoddy_init(Shoddy *self, PyObject *args, PyObject *kwds) + { + if (PyList_Type.tp_init((PyObject *)self, args, kwds) < 0) + return -1; + self->state = 0; + return 0; + } + +In the :attr:`__init__` method for our type, we can see how to call through to +the :attr:`__init__` method of the base type. + +This pattern is important when writing a type with custom :attr:`new` and +:attr:`dealloc` methods. The :attr:`new` method should not actually create the +memory for the object with :attr:`tp_alloc`, that will be handled by the base +class when calling its :attr:`tp_new`. + +When filling out the :cfunc:`PyTypeObject` for the :class:`Shoddy` type, you see +a slot for :cfunc:`tp_base`. Due to cross platform compiler issues, you can't +fill that field directly with the :cfunc:`PyList_Type`; it can be done later in +the module's :cfunc:`init` function. :: + + PyMODINIT_FUNC + initshoddy(void) + { + PyObject *m; + + ShoddyType.tp_base = &PyList_Type; + if (PyType_Ready(&ShoddyType) < 0) + return; + + m = Py_InitModule3("shoddy", NULL, "Shoddy module"); + if (m == NULL) + return; + + Py_INCREF(&ShoddyType); + PyModule_AddObject(m, "Shoddy", (PyObject *) &ShoddyType); + } + +Before calling :cfunc:`PyType_Ready`, the type structure must have the +:attr:`tp_base` slot filled in. When we are deriving a new type, it is not +necessary to fill out the :attr:`tp_alloc` slot with :cfunc:`PyType_GenericNew` +-- the allocate function from the base type will be inherited. + +After that, calling :cfunc:`PyType_Ready` and adding the type object to the +module is the same as with the basic :class:`Noddy` examples. + + +.. _dnt-type-methods: + +Type Methods +============ + +This section aims to give a quick fly-by on the various type methods you can +implement and what they do. + +Here is the definition of :ctype:`PyTypeObject`, with some fields only used in +debug builds omitted: + +.. literalinclude:: ../includes/typestruct.h + + +Now that's a *lot* of methods. Don't worry too much though - if you have a type +you want to define, the chances are very good that you will only implement a +handful of these. + +As you probably expect by now, we're going to go over this and give more +information about the various handlers. We won't go in the order they are +defined in the structure, because there is a lot of historical baggage that +impacts the ordering of the fields; be sure your type initialization keeps the +fields in the right order! It's often easiest to find an example that includes +all the fields you need (even if they're initialized to ``0``) and then change +the values to suit your new type. :: + + char *tp_name; /* For printing */ + +The name of the type - as mentioned in the last section, this will appear in +various places, almost entirely for diagnostic purposes. Try to choose something +that will be helpful in such a situation! :: + + int tp_basicsize, tp_itemsize; /* For allocation */ + +These fields tell the runtime how much memory to allocate when new objects of +this type are created. Python has some built-in support for variable length +structures (think: strings, lists) which is where the :attr:`tp_itemsize` field +comes in. This will be dealt with later. :: + + char *tp_doc; + +Here you can put a string (or its address) that you want returned when the +Python script references ``obj.__doc__`` to retrieve the doc string. + +Now we come to the basic type methods---the ones most extension types will +implement. + + +Finalization and De-allocation +------------------------------ + +.. index:: + single: object; deallocation + single: deallocation, object + single: object; finalization + single: finalization, of objects + +:: + + destructor tp_dealloc; + +This function is called when the reference count of the instance of your type is +reduced to zero and the Python interpreter wants to reclaim it. If your type +has memory to free or other clean-up to perform, put it here. The object itself +needs to be freed here as well. Here is an example of this function:: + + static void + newdatatype_dealloc(newdatatypeobject * obj) + { + free(obj->obj_UnderlyingDatatypePtr); + obj->ob_type->tp_free(obj); + } + +.. index:: + single: PyErr_Fetch() + single: PyErr_Restore() + +One important requirement of the deallocator function is that it leaves any +pending exceptions alone. This is important since deallocators are frequently +called as the interpreter unwinds the Python stack; when the stack is unwound +due to an exception (rather than normal returns), nothing is done to protect the +deallocators from seeing that an exception has already been set. Any actions +which a deallocator performs which may cause additional Python code to be +executed may detect that an exception has been set. This can lead to misleading +errors from the interpreter. The proper way to protect against this is to save +a pending exception before performing the unsafe action, and restoring it when +done. This can be done using the :cfunc:`PyErr_Fetch` and +:cfunc:`PyErr_Restore` functions:: + + static void + my_dealloc(PyObject *obj) + { + MyObject *self = (MyObject *) obj; + PyObject *cbresult; + + if (self->my_callback != NULL) { + PyObject *err_type, *err_value, *err_traceback; + int have_error = PyErr_Occurred() ? 1 : 0; + + if (have_error) + PyErr_Fetch(&err_type, &err_value, &err_traceback); + + cbresult = PyObject_CallObject(self->my_callback, NULL); + if (cbresult == NULL) + PyErr_WriteUnraisable(self->my_callback); + else + Py_DECREF(cbresult); + + if (have_error) + PyErr_Restore(err_type, err_value, err_traceback); + + Py_DECREF(self->my_callback); + } + obj->ob_type->tp_free((PyObject*)self); + } + + +Object Presentation +------------------- + +.. index:: + builtin: repr + builtin: str + +In Python, there are two ways to generate a textual representation of an object: +the :func:`repr` function, and the :func:`str` function. (The :func:`print` +function just calls :func:`str`.) These handlers are both optional. + +:: + + reprfunc tp_repr; + reprfunc tp_str; + +The :attr:`tp_repr` handler should return a string object containing a +representation of the instance for which it is called. Here is a simple +example:: + + static PyObject * + newdatatype_repr(newdatatypeobject * obj) + { + return PyString_FromFormat("Repr-ified_newdatatype{{size:\%d}}", + obj->obj_UnderlyingDatatypePtr->size); + } + +If no :attr:`tp_repr` handler is specified, the interpreter will supply a +representation that uses the type's :attr:`tp_name` and a uniquely-identifying +value for the object. + +The :attr:`tp_str` handler is to :func:`str` what the :attr:`tp_repr` handler +described above is to :func:`repr`; that is, it is called when Python code calls +:func:`str` on an instance of your object. Its implementation is very similar +to the :attr:`tp_repr` function, but the resulting string is intended for human +consumption. If :attr:`tp_str` is not specified, the :attr:`tp_repr` handler is +used instead. + +Here is a simple example:: + + static PyObject * + newdatatype_str(newdatatypeobject * obj) + { + return PyString_FromFormat("Stringified_newdatatype{{size:\%d}}", + obj->obj_UnderlyingDatatypePtr->size); + } + +The print function will be called whenever Python needs to "print" an instance +of the type. For example, if 'node' is an instance of type TreeNode, then the +print function is called when Python code calls:: + + print node + +There is a flags argument and one flag, :const:`Py_PRINT_RAW`, and it suggests +that you print without string quotes and possibly without interpreting escape +sequences. + +The print function receives a file object as an argument. You will likely want +to write to that file object. + +Here is a sample print function:: + + static int + newdatatype_print(newdatatypeobject *obj, FILE *fp, int flags) + { + if (flags & Py_PRINT_RAW) { + fprintf(fp, "<{newdatatype object--size: %d}>", + obj->obj_UnderlyingDatatypePtr->size); + } + else { + fprintf(fp, "\"<{newdatatype object--size: %d}>\"", + obj->obj_UnderlyingDatatypePtr->size); + } + return 0; + } + + +Attribute Management +-------------------- + +For every object which can support attributes, the corresponding type must +provide the functions that control how the attributes are resolved. There needs +to be a function which can retrieve attributes (if any are defined), and another +to set attributes (if setting attributes is allowed). Removing an attribute is +a special case, for which the new value passed to the handler is *NULL*. + +Python supports two pairs of attribute handlers; a type that supports attributes +only needs to implement the functions for one pair. The difference is that one +pair takes the name of the attribute as a :ctype:`char\*`, while the other +accepts a :ctype:`PyObject\*`. Each type can use whichever pair makes more +sense for the implementation's convenience. :: + + getattrfunc tp_getattr; /* char * version */ + setattrfunc tp_setattr; + /* ... */ + getattrofunc tp_getattrofunc; /* PyObject * version */ + setattrofunc tp_setattrofunc; + +If accessing attributes of an object is always a simple operation (this will be +explained shortly), there are generic implementations which can be used to +provide the :ctype:`PyObject\*` version of the attribute management functions. +The actual need for type-specific attribute handlers almost completely +disappeared starting with Python 2.2, though there are many examples which have +not been updated to use some of the new generic mechanism that is available. + + +Generic Attribute Management +^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. versionadded:: 2.2 + +Most extension types only use *simple* attributes. So, what makes the +attributes simple? There are only a couple of conditions that must be met: + +#. The name of the attributes must be known when :cfunc:`PyType_Ready` is + called. + +#. No special processing is needed to record that an attribute was looked up or + set, nor do actions need to be taken based on the value. + +Note that this list does not place any restrictions on the values of the +attributes, when the values are computed, or how relevant data is stored. + +When :cfunc:`PyType_Ready` is called, it uses three tables referenced by the +type object to create *descriptors* which are placed in the dictionary of the +type object. Each descriptor controls access to one attribute of the instance +object. Each of the tables is optional; if all three are *NULL*, instances of +the type will only have attributes that are inherited from their base type, and +should leave the :attr:`tp_getattro` and :attr:`tp_setattro` fields *NULL* as +well, allowing the base type to handle attributes. + +The tables are declared as three fields of the type object:: + + struct PyMethodDef *tp_methods; + struct PyMemberDef *tp_members; + struct PyGetSetDef *tp_getset; + +If :attr:`tp_methods` is not *NULL*, it must refer to an array of +:ctype:`PyMethodDef` structures. Each entry in the table is an instance of this +structure:: + + typedef struct PyMethodDef { + char *ml_name; /* method name */ + PyCFunction ml_meth; /* implementation function */ + int ml_flags; /* flags */ + char *ml_doc; /* docstring */ + } PyMethodDef; + +One entry should be defined for each method provided by the type; no entries are +needed for methods inherited from a base type. One additional entry is needed +at the end; it is a sentinel that marks the end of the array. The +:attr:`ml_name` field of the sentinel must be *NULL*. + +XXX Need to refer to some unified discussion of the structure fields, shared +with the next section. + +The second table is used to define attributes which map directly to data stored +in the instance. A variety of primitive C types are supported, and access may +be read-only or read-write. The structures in the table are defined as:: + + typedef struct PyMemberDef { + char *name; + int type; + int offset; + int flags; + char *doc; + } PyMemberDef; + +For each entry in the table, a descriptor will be constructed and added to the +type which will be able to extract a value from the instance structure. The +:attr:`type` field should contain one of the type codes defined in the +:file:`structmember.h` header; the value will be used to determine how to +convert Python values to and from C values. The :attr:`flags` field is used to +store flags which control how the attribute can be accessed. + +XXX Need to move some of this to a shared section! + +The following flag constants are defined in :file:`structmember.h`; they may be +combined using bitwise-OR. + ++---------------------------+----------------------------------------------+ +| Constant | Meaning | ++===========================+==============================================+ +| :const:`READONLY` | Never writable. | ++---------------------------+----------------------------------------------+ +| :const:`RO` | Shorthand for :const:`READONLY`. | ++---------------------------+----------------------------------------------+ +| :const:`READ_RESTRICTED` | Not readable in restricted mode. | ++---------------------------+----------------------------------------------+ +| :const:`WRITE_RESTRICTED` | Not writable in restricted mode. | ++---------------------------+----------------------------------------------+ +| :const:`RESTRICTED` | Not readable or writable in restricted mode. | ++---------------------------+----------------------------------------------+ + +.. index:: + single: READONLY + single: RO + single: READ_RESTRICTED + single: WRITE_RESTRICTED + single: RESTRICTED + +An interesting advantage of using the :attr:`tp_members` table to build +descriptors that are used at runtime is that any attribute defined this way can +have an associated doc string simply by providing the text in the table. An +application can use the introspection API to retrieve the descriptor from the +class object, and get the doc string using its :attr:`__doc__` attribute. + +As with the :attr:`tp_methods` table, a sentinel entry with a :attr:`name` value +of *NULL* is required. + +.. % XXX Descriptors need to be explained in more detail somewhere, but +.. % not here. +.. % +.. % Descriptor objects have two handler functions which correspond to +.. % the \member{tp_getattro} and \member{tp_setattro} handlers. The +.. % \method{__get__()} handler is a function which is passed the +.. % descriptor, instance, and type objects, and returns the value of the +.. % attribute, or it returns \NULL{} and sets an exception. The +.. % \method{__set__()} handler is passed the descriptor, instance, type, +.. % and new value; + + +Type-specific Attribute Management +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +For simplicity, only the :ctype:`char\*` version will be demonstrated here; the +type of the name parameter is the only difference between the :ctype:`char\*` +and :ctype:`PyObject\*` flavors of the interface. This example effectively does +the same thing as the generic example above, but does not use the generic +support added in Python 2.2. The value in showing this is two-fold: it +demonstrates how basic attribute management can be done in a way that is +portable to older versions of Python, and explains how the handler functions are +called, so that if you do need to extend their functionality, you'll understand +what needs to be done. + +The :attr:`tp_getattr` handler is called when the object requires an attribute +look-up. It is called in the same situations where the :meth:`__getattr__` +method of a class would be called. + +A likely way to handle this is (1) to implement a set of functions (such as +:cfunc:`newdatatype_getSize` and :cfunc:`newdatatype_setSize` in the example +below), (2) provide a method table listing these functions, and (3) provide a +getattr function that returns the result of a lookup in that table. The method +table uses the same structure as the :attr:`tp_methods` field of the type +object. + +Here is an example:: + + static PyMethodDef newdatatype_methods[] = { + {"getSize", (PyCFunction)newdatatype_getSize, METH_VARARGS, + "Return the current size."}, + {"setSize", (PyCFunction)newdatatype_setSize, METH_VARARGS, + "Set the size."}, + {NULL, NULL, 0, NULL} /* sentinel */ + }; + + static PyObject * + newdatatype_getattr(newdatatypeobject *obj, char *name) + { + return Py_FindMethod(newdatatype_methods, (PyObject *)obj, name); + } + +The :attr:`tp_setattr` handler is called when the :meth:`__setattr__` or +:meth:`__delattr__` method of a class instance would be called. When an +attribute should be deleted, the third parameter will be *NULL*. Here is an +example that simply raises an exception; if this were really all you wanted, the +:attr:`tp_setattr` handler should be set to *NULL*. :: + + static int + newdatatype_setattr(newdatatypeobject *obj, char *name, PyObject *v) + { + (void)PyErr_Format(PyExc_RuntimeError, "Read-only attribute: \%s", name); + return -1; + } + + +Object Comparison +----------------- + +:: + + cmpfunc tp_compare; + +The :attr:`tp_compare` handler is called when comparisons are needed and the +object does not implement the specific rich comparison method which matches the +requested comparison. (It is always used if defined and the +:cfunc:`PyObject_Compare` or :cfunc:`PyObject_Cmp` functions are used, or if +:func:`cmp` is used from Python.) It is analogous to the :meth:`__cmp__` method. +This function should return ``-1`` if *obj1* is less than *obj2*, ``0`` if they +are equal, and ``1`` if *obj1* is greater than *obj2*. (It was previously +allowed to return arbitrary negative or positive integers for less than and +greater than, respectively; as of Python 2.2, this is no longer allowed. In the +future, other return values may be assigned a different meaning.) + +A :attr:`tp_compare` handler may raise an exception. In this case it should +return a negative value. The caller has to test for the exception using +:cfunc:`PyErr_Occurred`. + +Here is a sample implementation:: + + static int + newdatatype_compare(newdatatypeobject * obj1, newdatatypeobject * obj2) + { + long result; + + if (obj1->obj_UnderlyingDatatypePtr->size < + obj2->obj_UnderlyingDatatypePtr->size) { + result = -1; + } + else if (obj1->obj_UnderlyingDatatypePtr->size > + obj2->obj_UnderlyingDatatypePtr->size) { + result = 1; + } + else { + result = 0; + } + return result; + } + + +Abstract Protocol Support +------------------------- + +Python supports a variety of *abstract* 'protocols;' the specific interfaces +provided to use these interfaces are documented in :ref:`abstract`. + + +A number of these abstract interfaces were defined early in the development of +the Python implementation. In particular, the number, mapping, and sequence +protocols have been part of Python since the beginning. Other protocols have +been added over time. For protocols which depend on several handler routines +from the type implementation, the older protocols have been defined as optional +blocks of handlers referenced by the type object. For newer protocols there are +additional slots in the main type object, with a flag bit being set to indicate +that the slots are present and should be checked by the interpreter. (The flag +bit does not indicate that the slot values are non-*NULL*. The flag may be set +to indicate the presence of a slot, but a slot may still be unfilled.) :: + + PyNumberMethods tp_as_number; + PySequenceMethods tp_as_sequence; + PyMappingMethods tp_as_mapping; + +If you wish your object to be able to act like a number, a sequence, or a +mapping object, then you place the address of a structure that implements the C +type :ctype:`PyNumberMethods`, :ctype:`PySequenceMethods`, or +:ctype:`PyMappingMethods`, respectively. It is up to you to fill in this +structure with appropriate values. You can find examples of the use of each of +these in the :file:`Objects` directory of the Python source distribution. :: + + hashfunc tp_hash; + +This function, if you choose to provide it, should return a hash number for an +instance of your data type. Here is a moderately pointless example:: + + static long + newdatatype_hash(newdatatypeobject *obj) + { + long result; + result = obj->obj_UnderlyingDatatypePtr->size; + result = result * 3; + return result; + } + +:: + + ternaryfunc tp_call; + +This function is called when an instance of your data type is "called", for +example, if ``obj1`` is an instance of your data type and the Python script +contains ``obj1('hello')``, the :attr:`tp_call` handler is invoked. + +This function takes three arguments: + +#. *arg1* is the instance of the data type which is the subject of the call. If + the call is ``obj1('hello')``, then *arg1* is ``obj1``. + +#. *arg2* is a tuple containing the arguments to the call. You can use + :cfunc:`PyArg_ParseTuple` to extract the arguments. + +#. *arg3* is a dictionary of keyword arguments that were passed. If this is + non-*NULL* and you support keyword arguments, use + :cfunc:`PyArg_ParseTupleAndKeywords` to extract the arguments. If you do not + want to support keyword arguments and this is non-*NULL*, raise a + :exc:`TypeError` with a message saying that keyword arguments are not supported. + +Here is a desultory example of the implementation of the call function. :: + + /* Implement the call function. + * obj1 is the instance receiving the call. + * obj2 is a tuple containing the arguments to the call, in this + * case 3 strings. + */ + static PyObject * + newdatatype_call(newdatatypeobject *obj, PyObject *args, PyObject *other) + { + PyObject *result; + char *arg1; + char *arg2; + char *arg3; + + if (!PyArg_ParseTuple(args, "sss:call", &arg1, &arg2, &arg3)) { + return NULL; + } + result = PyString_FromFormat( + "Returning -- value: [\%d] arg1: [\%s] arg2: [\%s] arg3: [\%s]\n", + obj->obj_UnderlyingDatatypePtr->size, + arg1, arg2, arg3); + printf("\%s", PyString_AS_STRING(result)); + return result; + } + +XXX some fields need to be added here... :: + + /* Added in release 2.2 */ + /* Iterators */ + getiterfunc tp_iter; + iternextfunc tp_iternext; + +These functions provide support for the iterator protocol. Any object which +wishes to support iteration over its contents (which may be generated during +iteration) must implement the ``tp_iter`` handler. Objects which are returned +by a ``tp_iter`` handler must implement both the ``tp_iter`` and ``tp_iternext`` +handlers. Both handlers take exactly one parameter, the instance for which they +are being called, and return a new reference. In the case of an error, they +should set an exception and return *NULL*. + +For an object which represents an iterable collection, the ``tp_iter`` handler +must return an iterator object. The iterator object is responsible for +maintaining the state of the iteration. For collections which can support +multiple iterators which do not interfere with each other (as lists and tuples +do), a new iterator should be created and returned. Objects which can only be +iterated over once (usually due to side effects of iteration) should implement +this handler by returning a new reference to themselves, and should also +implement the ``tp_iternext`` handler. File objects are an example of such an +iterator. + +Iterator objects should implement both handlers. The ``tp_iter`` handler should +return a new reference to the iterator (this is the same as the ``tp_iter`` +handler for objects which can only be iterated over destructively). The +``tp_iternext`` handler should return a new reference to the next object in the +iteration if there is one. If the iteration has reached the end, it may return +*NULL* without setting an exception or it may set :exc:`StopIteration`; avoiding +the exception can yield slightly better performance. If an actual error occurs, +it should set an exception and return *NULL*. + + +.. _weakref-support: + +Weak Reference Support +---------------------- + +One of the goals of Python's weak-reference implementation is to allow any type +to participate in the weak reference mechanism without incurring the overhead on +those objects which do not benefit by weak referencing (such as numbers). + +For an object to be weakly referencable, the extension must include a +:ctype:`PyObject\*` field in the instance structure for the use of the weak +reference mechanism; it must be initialized to *NULL* by the object's +constructor. It must also set the :attr:`tp_weaklistoffset` field of the +corresponding type object to the offset of the field. For example, the instance +type is defined with the following structure:: + + typedef struct { + PyObject_HEAD + PyClassObject *in_class; /* The class object */ + PyObject *in_dict; /* A dictionary */ + PyObject *in_weakreflist; /* List of weak references */ + } PyInstanceObject; + +The statically-declared type object for instances is defined this way:: + + PyTypeObject PyInstance_Type = { + PyObject_HEAD_INIT(&PyType_Type) + 0, + "module.instance", + + /* Lots of stuff omitted for brevity... */ + + Py_TPFLAGS_DEFAULT, /* tp_flags */ + 0, /* tp_doc */ + 0, /* tp_traverse */ + 0, /* tp_clear */ + 0, /* tp_richcompare */ + offsetof(PyInstanceObject, in_weakreflist), /* tp_weaklistoffset */ + }; + +The type constructor is responsible for initializing the weak reference list to +*NULL*:: + + static PyObject * + instance_new() { + /* Other initialization stuff omitted for brevity */ + + self->in_weakreflist = NULL; + + return (PyObject *) self; + } + +The only further addition is that the destructor needs to call the weak +reference manager to clear any weak references. This should be done before any +other parts of the destruction have occurred, but is only required if the weak +reference list is non-*NULL*:: + + static void + instance_dealloc(PyInstanceObject *inst) + { + /* Allocate temporaries if needed, but do not begin + destruction just yet. + */ + + if (inst->in_weakreflist != NULL) + PyObject_ClearWeakRefs((PyObject *) inst); + + /* Proceed with object destruction normally. */ + } + + +More Suggestions +---------------- + +Remember that you can omit most of these functions, in which case you provide +``0`` as a value. There are type definitions for each of the functions you must +provide. They are in :file:`object.h` in the Python include directory that +comes with the source distribution of Python. + +In order to learn how to implement any specific method for your new data type, +do the following: Download and unpack the Python source distribution. Go the +:file:`Objects` directory, then search the C source files for ``tp_`` plus the +function you want (for example, ``tp_compare``). You will find examples of the +function you want to implement. + +When you need to verify that an object is an instance of the type you are +implementing, use the :cfunc:`PyObject_TypeCheck` function. A sample of its use +might be something like the following:: + + if (! PyObject_TypeCheck(some_object, &MyType)) { + PyErr_SetString(PyExc_TypeError, "arg #1 not a mything"); + return NULL; + } + +.. rubric:: Footnotes + +.. [#] This is true when we know that the object is a basic type, like a string or a + float. + +.. [#] We relied on this in the :attr:`tp_dealloc` handler in this example, because our + type doesn't support garbage collection. Even if a type supports garbage + collection, there are calls that can be made to "untrack" the object from + garbage collection, however, these calls are advanced and not covered here. + +.. [#] We now know that the first and last members are strings, so perhaps we could be + less careful about decrementing their reference counts, however, we accept + instances of string subclasses. Even though deallocating normal strings won't + call back into our objects, we can't guarantee that deallocating an instance of + a string subclass won't. call back into out objects. + +.. [#] Even in the third version, we aren't guaranteed to avoid cycles. Instances of + string subclasses are allowed and string subclasses could allow cycles even if + normal strings don't. + diff --git a/Doc/extending/windows.rst b/Doc/extending/windows.rst new file mode 100644 index 0000000..7a66afe --- /dev/null +++ b/Doc/extending/windows.rst @@ -0,0 +1,280 @@ +.. highlightlang:: c + + +.. _building-on-windows: + +**************************************** +Building C and C++ Extensions on Windows +**************************************** + +.. % + +This chapter briefly explains how to create a Windows extension module for +Python using Microsoft Visual C++, and follows with more detailed background +information on how it works. The explanatory material is useful for both the +Windows programmer learning to build Python extensions and the Unix programmer +interested in producing software which can be successfully built on both Unix +and Windows. + +Module authors are encouraged to use the distutils approach for building +extension modules, instead of the one described in this section. You will still +need the C compiler that was used to build Python; typically Microsoft Visual +C++. + +.. note:: + + This chapter mentions a number of filenames that include an encoded Python + version number. These filenames are represented with the version number shown + as ``XY``; in practive, ``'X'`` will be the major version number and ``'Y'`` + will be the minor version number of the Python release you're working with. For + example, if you are using Python 2.2.1, ``XY`` will actually be ``22``. + + +.. _win-cookbook: + +A Cookbook Approach +=================== + +There are two approaches to building extension modules on Windows, just as there +are on Unix: use the :mod:`distutils` package to control the build process, or +do things manually. The distutils approach works well for most extensions; +documentation on using :mod:`distutils` to build and package extension modules +is available in :ref:`distutils-index`. This section describes the manual +approach to building Python extensions written in C or C++. + +To build extensions using these instructions, you need to have a copy of the +Python sources of the same version as your installed Python. You will need +Microsoft Visual C++ "Developer Studio"; project files are supplied for VC++ +version 7.1, but you can use older versions of VC++. Notice that you should use +the same version of VC++that was used to build Python itself. The example files +described here are distributed with the Python sources in the +:file:`PC\\example_nt\\` directory. + +#. **Copy the example files** --- The :file:`example_nt` directory is a + subdirectory of the :file:`PC` directory, in order to keep all the PC-specific + files under the same directory in the source distribution. However, the + :file:`example_nt` directory can't actually be used from this location. You + first need to copy or move it up one level, so that :file:`example_nt` is a + sibling of the :file:`PC` and :file:`Include` directories. Do all your work + from within this new location. + +#. **Open the project** --- From VC++, use the :menuselection:`File --> Open + Solution` dialog (not :menuselection:`File --> Open`!). Navigate to and select + the file :file:`example.sln`, in the *copy* of the :file:`example_nt` directory + you made above. Click Open. + +#. **Build the example DLL** --- In order to check that everything is set up + right, try building: + +#. Select a configuration. This step is optional. Choose + :menuselection:`Build --> Configuration Manager --> Active Solution Configuration` + and select either :guilabel:`Release` or :guilabel:`Debug`. If you skip this + step, VC++ will use the Debug configuration by default. + +#. Build the DLL. Choose :menuselection:`Build --> Build Solution`. This + creates all intermediate and result files in a subdirectory called either + :file:`Debug` or :file:`Release`, depending on which configuration you selected + in the preceding step. + +#. **Testing the debug-mode DLL** --- Once the Debug build has succeeded, bring + up a DOS box, and change to the :file:`example_nt\\Debug` directory. You should + now be able to repeat the following session (``C>`` is the DOS prompt, ``>>>`` + is the Python prompt; note that build information and various debug output from + Python may not match this screen dump exactly):: + + C>..\..\PCbuild\python_d + Adding parser accelerators ... + Done. + Python 2.2 (#28, Dec 19 2001, 23:26:37) [MSC 32 bit (Intel)] on win32 + Type "copyright", "credits" or "license" for more information. + >>> import example + [4897 refs] + >>> example.foo() + Hello, world + [4903 refs] + >>> + + Congratulations! You've successfully built your first Python extension module. + +#. **Creating your own project** --- Choose a name and create a directory for + it. Copy your C sources into it. Note that the module source file name does + not necessarily have to match the module name, but the name of the + initialization function should match the module name --- you can only import a + module :mod:`spam` if its initialization function is called :cfunc:`initspam`, + and it should call :cfunc:`Py_InitModule` with the string ``"spam"`` as its + first argument (use the minimal :file:`example.c` in this directory as a guide). + By convention, it lives in a file called :file:`spam.c` or :file:`spammodule.c`. + The output file should be called :file:`spam.dll` or :file:`spam.pyd` (the + latter is supported to avoid confusion with a system library :file:`spam.dll` to + which your module could be a Python interface) in Release mode, or + :file:`spam_d.dll` or :file:`spam_d.pyd` in Debug mode. + + Now your options are: + +#. Copy :file:`example.sln` and :file:`example.vcproj`, rename them to + :file:`spam.\*`, and edit them by hand, or + +#. Create a brand new project; instructions are below. + + In either case, copy :file:`example_nt\\example.def` to :file:`spam\\spam.def`, + and edit the new :file:`spam.def` so its second line contains the string + '``initspam``'. If you created a new project yourself, add the file + :file:`spam.def` to the project now. (This is an annoying little file with only + two lines. An alternative approach is to forget about the :file:`.def` file, + and add the option :option:`/export:initspam` somewhere to the Link settings, by + manually editing the setting in Project Properties dialog). + +#. **Creating a brand new project** --- Use the :menuselection:`File --> New + --> Project` dialog to create a new Project Workspace. Select :guilabel:`Visual + C++ Projects/Win32/ Win32 Project`, enter the name (``spam``), and make sure the + Location is set to parent of the :file:`spam` directory you have created (which + should be a direct subdirectory of the Python build tree, a sibling of + :file:`Include` and :file:`PC`). Select Win32 as the platform (in my version, + this is the only choice). Make sure the Create new workspace radio button is + selected. Click OK. + + You should now create the file :file:`spam.def` as instructed in the previous + section. Add the source files to the project, using :menuselection:`Project --> + Add Existing Item`. Set the pattern to ``*.*`` and select both :file:`spam.c` + and :file:`spam.def` and click OK. (Inserting them one by one is fine too.) + + Now open the :menuselection:`Project --> spam properties` dialog. You only need + to change a few settings. Make sure :guilabel:`All Configurations` is selected + from the :guilabel:`Settings for:` dropdown list. Select the C/C++ tab. Choose + the General category in the popup menu at the top. Type the following text in + the entry box labeled :guilabel:`Additional Include Directories`:: + + ..\Include,..\PC + + Then, choose the General category in the Linker tab, and enter :: + + ..\PCbuild + + in the text box labelled :guilabel:`Additional library Directories`. + + Now you need to add some mode-specific settings: + + Select :guilabel:`Release` in the :guilabel:`Configuration` dropdown list. + Choose the :guilabel:`Link` tab, choose the :guilabel:`Input` category, and + append ``pythonXY.lib`` to the list in the :guilabel:`Additional Dependencies` + box. + + Select :guilabel:`Debug` in the :guilabel:`Configuration` dropdown list, and + append ``pythonXY_d.lib`` to the list in the :guilabel:`Additional Dependencies` + box. Then click the C/C++ tab, select :guilabel:`Code Generation`, and select + :guilabel:`Multi-threaded Debug DLL` from the :guilabel:`Runtime library` + dropdown list. + + Select :guilabel:`Release` again from the :guilabel:`Configuration` dropdown + list. Select :guilabel:`Multi-threaded DLL` from the :guilabel:`Runtime + library` dropdown list. + +If your module creates a new type, you may have trouble with this line:: + + PyObject_HEAD_INIT(&PyType_Type) + +Change it to:: + + PyObject_HEAD_INIT(NULL) + +and add the following to the module initialization function:: + + MyObject_Type.ob_type = &PyType_Type; + +Refer to section 3 of the `Python FAQ `_ for +details on why you must do this. + + +.. _dynamic-linking: + +Differences Between Unix and Windows +==================================== + +.. sectionauthor:: Chris Phoenix + + +Unix and Windows use completely different paradigms for run-time loading of +code. Before you try to build a module that can be dynamically loaded, be aware +of how your system works. + +In Unix, a shared object (:file:`.so`) file contains code to be used by the +program, and also the names of functions and data that it expects to find in the +program. When the file is joined to the program, all references to those +functions and data in the file's code are changed to point to the actual +locations in the program where the functions and data are placed in memory. +This is basically a link operation. + +In Windows, a dynamic-link library (:file:`.dll`) file has no dangling +references. Instead, an access to functions or data goes through a lookup +table. So the DLL code does not have to be fixed up at runtime to refer to the +program's memory; instead, the code already uses the DLL's lookup table, and the +lookup table is modified at runtime to point to the functions and data. + +In Unix, there is only one type of library file (:file:`.a`) which contains code +from several object files (:file:`.o`). During the link step to create a shared +object file (:file:`.so`), the linker may find that it doesn't know where an +identifier is defined. The linker will look for it in the object files in the +libraries; if it finds it, it will include all the code from that object file. + +In Windows, there are two types of library, a static library and an import +library (both called :file:`.lib`). A static library is like a Unix :file:`.a` +file; it contains code to be included as necessary. An import library is +basically used only to reassure the linker that a certain identifier is legal, +and will be present in the program when the DLL is loaded. So the linker uses +the information from the import library to build the lookup table for using +identifiers that are not included in the DLL. When an application or a DLL is +linked, an import library may be generated, which will need to be used for all +future DLLs that depend on the symbols in the application or DLL. + +Suppose you are building two dynamic-load modules, B and C, which should share +another block of code A. On Unix, you would *not* pass :file:`A.a` to the +linker for :file:`B.so` and :file:`C.so`; that would cause it to be included +twice, so that B and C would each have their own copy. In Windows, building +:file:`A.dll` will also build :file:`A.lib`. You *do* pass :file:`A.lib` to the +linker for B and C. :file:`A.lib` does not contain code; it just contains +information which will be used at runtime to access A's code. + +In Windows, using an import library is sort of like using ``import spam``; it +gives you access to spam's names, but does not create a separate copy. On Unix, +linking with a library is more like ``from spam import *``; it does create a +separate copy. + + +.. _win-dlls: + +Using DLLs in Practice +====================== + +.. sectionauthor:: Chris Phoenix + + +Windows Python is built in Microsoft Visual C++; using other compilers may or +may not work (though Borland seems to). The rest of this section is MSVC++ +specific. + +When creating DLLs in Windows, you must pass :file:`pythonXY.lib` to the linker. +To build two DLLs, spam and ni (which uses C functions found in spam), you could +use these commands:: + + cl /LD /I/python/include spam.c ../libs/pythonXY.lib + cl /LD /I/python/include ni.c spam.lib ../libs/pythonXY.lib + +The first command created three files: :file:`spam.obj`, :file:`spam.dll` and +:file:`spam.lib`. :file:`Spam.dll` does not contain any Python functions (such +as :cfunc:`PyArg_ParseTuple`), but it does know how to find the Python code +thanks to :file:`pythonXY.lib`. + +The second command created :file:`ni.dll` (and :file:`.obj` and :file:`.lib`), +which knows how to find the necessary functions from spam, and also from the +Python executable. + +Not every identifier is exported to the lookup table. If you want any other +modules (including Python) to be able to see your identifiers, you have to say +``_declspec(dllexport)``, as in ``void _declspec(dllexport) initspam(void)`` or +``PyObject _declspec(dllexport) *NiGetSpamData(void)``. + +Developer Studio will throw in a lot of import libraries that you do not really +need, adding about 100K to your executable. To get rid of them, use the Project +Settings dialog, Link tab, to specify *ignore default libraries*. Add the +correct :file:`msvcrtxx.lib` to the list of libraries. + diff --git a/Doc/howto/advocacy.rst b/Doc/howto/advocacy.rst new file mode 100644 index 0000000..1f1754a --- /dev/null +++ b/Doc/howto/advocacy.rst @@ -0,0 +1,356 @@ +************************* + Python Advocacy HOWTO +************************* + +:Author: A.M. Kuchling +:Release: 0.03 + + +.. topic:: Abstract + + It's usually difficult to get your management to accept open source software, + and Python is no exception to this rule. This document discusses reasons to use + Python, strategies for winning acceptance, facts and arguments you can use, and + cases where you *shouldn't* try to use Python. + + +Reasons to Use Python +===================== + +There are several reasons to incorporate a scripting language into your +development process, and this section will discuss them, and why Python has some +properties that make it a particularly good choice. + + +Programmability +--------------- + +Programs are often organized in a modular fashion. Lower-level operations are +grouped together, and called by higher-level functions, which may in turn be +used as basic operations by still further upper levels. + +For example, the lowest level might define a very low-level set of functions for +accessing a hash table. The next level might use hash tables to store the +headers of a mail message, mapping a header name like ``Date`` to a value such +as ``Tue, 13 May 1997 20:00:54 -0400``. A yet higher level may operate on +message objects, without knowing or caring that message headers are stored in a +hash table, and so forth. + +Often, the lowest levels do very simple things; they implement a data structure +such as a binary tree or hash table, or they perform some simple computation, +such as converting a date string to a number. The higher levels then contain +logic connecting these primitive operations. Using the approach, the primitives +can be seen as basic building blocks which are then glued together to produce +the complete product. + +Why is this design approach relevant to Python? Because Python is well suited +to functioning as such a glue language. A common approach is to write a Python +module that implements the lower level operations; for the sake of speed, the +implementation might be in C, Java, or even Fortran. Once the primitives are +available to Python programs, the logic underlying higher level operations is +written in the form of Python code. The high-level logic is then more +understandable, and easier to modify. + +John Ousterhout wrote a paper that explains this idea at greater length, +entitled "Scripting: Higher Level Programming for the 21st Century". I +recommend that you read this paper; see the references for the URL. Ousterhout +is the inventor of the Tcl language, and therefore argues that Tcl should be +used for this purpose; he only briefly refers to other languages such as Python, +Perl, and Lisp/Scheme, but in reality, Ousterhout's argument applies to +scripting languages in general, since you could equally write extensions for any +of the languages mentioned above. + + +Prototyping +----------- + +In *The Mythical Man-Month*, Fredrick Brooks suggests the following rule when +planning software projects: "Plan to throw one away; you will anyway." Brooks +is saying that the first attempt at a software design often turns out to be +wrong; unless the problem is very simple or you're an extremely good designer, +you'll find that new requirements and features become apparent once development +has actually started. If these new requirements can't be cleanly incorporated +into the program's structure, you're presented with two unpleasant choices: +hammer the new features into the program somehow, or scrap everything and write +a new version of the program, taking the new features into account from the +beginning. + +Python provides you with a good environment for quickly developing an initial +prototype. That lets you get the overall program structure and logic right, and +you can fine-tune small details in the fast development cycle that Python +provides. Once you're satisfied with the GUI interface or program output, you +can translate the Python code into C++, Fortran, Java, or some other compiled +language. + +Prototyping means you have to be careful not to use too many Python features +that are hard to implement in your other language. Using ``eval()``, or regular +expressions, or the :mod:`pickle` module, means that you're going to need C or +Java libraries for formula evaluation, regular expressions, and serialization, +for example. But it's not hard to avoid such tricky code, and in the end the +translation usually isn't very difficult. The resulting code can be rapidly +debugged, because any serious logical errors will have been removed from the +prototype, leaving only more minor slip-ups in the translation to track down. + +This strategy builds on the earlier discussion of programmability. Using Python +as glue to connect lower-level components has obvious relevance for constructing +prototype systems. In this way Python can help you with development, even if +end users never come in contact with Python code at all. If the performance of +the Python version is adequate and corporate politics allow it, you may not need +to do a translation into C or Java, but it can still be faster to develop a +prototype and then translate it, instead of attempting to produce the final +version immediately. + +One example of this development strategy is Microsoft Merchant Server. Version +1.0 was written in pure Python, by a company that subsequently was purchased by +Microsoft. Version 2.0 began to translate the code into C++, shipping with some +C++code and some Python code. Version 3.0 didn't contain any Python at all; all +the code had been translated into C++. Even though the product doesn't contain +a Python interpreter, the Python language has still served a useful purpose by +speeding up development. + +This is a very common use for Python. Past conference papers have also +described this approach for developing high-level numerical algorithms; see +David M. Beazley and Peter S. Lomdahl's paper "Feeding a Large-scale Physics +Application to Python" in the references for a good example. If an algorithm's +basic operations are things like "Take the inverse of this 4000x4000 matrix", +and are implemented in some lower-level language, then Python has almost no +additional performance cost; the extra time required for Python to evaluate an +expression like ``m.invert()`` is dwarfed by the cost of the actual computation. +It's particularly good for applications where seemingly endless tweaking is +required to get things right. GUI interfaces and Web sites are prime examples. + +The Python code is also shorter and faster to write (once you're familiar with +Python), so it's easier to throw it away if you decide your approach was wrong; +if you'd spent two weeks working on it instead of just two hours, you might +waste time trying to patch up what you've got out of a natural reluctance to +admit that those two weeks were wasted. Truthfully, those two weeks haven't +been wasted, since you've learnt something about the problem and the technology +you're using to solve it, but it's human nature to view this as a failure of +some sort. + + +Simplicity and Ease of Understanding +------------------------------------ + +Python is definitely *not* a toy language that's only usable for small tasks. +The language features are general and powerful enough to enable it to be used +for many different purposes. It's useful at the small end, for 10- or 20-line +scripts, but it also scales up to larger systems that contain thousands of lines +of code. + +However, this expressiveness doesn't come at the cost of an obscure or tricky +syntax. While Python has some dark corners that can lead to obscure code, there +are relatively few such corners, and proper design can isolate their use to only +a few classes or modules. It's certainly possible to write confusing code by +using too many features with too little concern for clarity, but most Python +code can look a lot like a slightly-formalized version of human-understandable +pseudocode. + +In *The New Hacker's Dictionary*, Eric S. Raymond gives the following definition +for "compact": + +.. epigraph:: + + Compact *adj.* Of a design, describes the valuable property that it can all be + apprehended at once in one's head. This generally means the thing created from + the design can be used with greater facility and fewer errors than an equivalent + tool that is not compact. Compactness does not imply triviality or lack of + power; for example, C is compact and FORTRAN is not, but C is more powerful than + FORTRAN. Designs become non-compact through accreting features and cruft that + don't merge cleanly into the overall design scheme (thus, some fans of Classic C + maintain that ANSI C is no longer compact). + + (From http://www.catb.org/ esr/jargon/html/C/compact.html) + +In this sense of the word, Python is quite compact, because the language has +just a few ideas, which are used in lots of places. Take namespaces, for +example. Import a module with ``import math``, and you create a new namespace +called ``math``. Classes are also namespaces that share many of the properties +of modules, and have a few of their own; for example, you can create instances +of a class. Instances? They're yet another namespace. Namespaces are currently +implemented as Python dictionaries, so they have the same methods as the +standard dictionary data type: .keys() returns all the keys, and so forth. + +This simplicity arises from Python's development history. The language syntax +derives from different sources; ABC, a relatively obscure teaching language, is +one primary influence, and Modula-3 is another. (For more information about ABC +and Modula-3, consult their respective Web sites at http://www.cwi.nl/ +steven/abc/ and http://www.m3.org.) Other features have come from C, Icon, +Algol-68, and even Perl. Python hasn't really innovated very much, but instead +has tried to keep the language small and easy to learn, building on ideas that +have been tried in other languages and found useful. + +Simplicity is a virtue that should not be underestimated. It lets you learn the +language more quickly, and then rapidly write code, code that often works the +first time you run it. + + +Java Integration +---------------- + +If you're working with Java, Jython (http://www.jython.org/) is definitely worth +your attention. Jython is a re-implementation of Python in Java that compiles +Python code into Java bytecodes. The resulting environment has very tight, +almost seamless, integration with Java. It's trivial to access Java classes +from Python, and you can write Python classes that subclass Java classes. +Jython can be used for prototyping Java applications in much the same way +CPython is used, and it can also be used for test suites for Java code, or +embedded in a Java application to add scripting capabilities. + + +Arguments and Rebuttals +======================= + +Let's say that you've decided upon Python as the best choice for your +application. How can you convince your management, or your fellow developers, +to use Python? This section lists some common arguments against using Python, +and provides some possible rebuttals. + +**Python is freely available software that doesn't cost anything. How good can +it be?** + +Very good, indeed. These days Linux and Apache, two other pieces of open source +software, are becoming more respected as alternatives to commercial software, +but Python hasn't had all the publicity. + +Python has been around for several years, with many users and developers. +Accordingly, the interpreter has been used by many people, and has gotten most +of the bugs shaken out of it. While bugs are still discovered at intervals, +they're usually either quite obscure (they'd have to be, for no one to have run +into them before) or they involve interfaces to external libraries. The +internals of the language itself are quite stable. + +Having the source code should be viewed as making the software available for +peer review; people can examine the code, suggest (and implement) improvements, +and track down bugs. To find out more about the idea of open source code, along +with arguments and case studies supporting it, go to http://www.opensource.org. + +**Who's going to support it?** + +Python has a sizable community of developers, and the number is still growing. +The Internet community surrounding the language is an active one, and is worth +being considered another one of Python's advantages. Most questions posted to +the comp.lang.python newsgroup are quickly answered by someone. + +Should you need to dig into the source code, you'll find it's clear and +well-organized, so it's not very difficult to write extensions and track down +bugs yourself. If you'd prefer to pay for support, there are companies and +individuals who offer commercial support for Python. + +**Who uses Python for serious work?** + +Lots of people; one interesting thing about Python is the surprising diversity +of applications that it's been used for. People are using Python to: + +* Run Web sites + +* Write GUI interfaces + +* Control number-crunching code on supercomputers + +* Make a commercial application scriptable by embedding the Python interpreter + inside it + +* Process large XML data sets + +* Build test suites for C or Java code + +Whatever your application domain is, there's probably someone who's used Python +for something similar. Yet, despite being useable for such high-end +applications, Python's still simple enough to use for little jobs. + +See http://wiki.python.org/moin/OrganizationsUsingPython for a list of some of +the organizations that use Python. + +**What are the restrictions on Python's use?** + +They're practically nonexistent. Consult the :file:`Misc/COPYRIGHT` file in the +source distribution, or http://www.python.org/doc/Copyright.html for the full +language, but it boils down to three conditions. + +* You have to leave the copyright notice on the software; if you don't include + the source code in a product, you have to put the copyright notice in the + supporting documentation. + +* Don't claim that the institutions that have developed Python endorse your + product in any way. + +* If something goes wrong, you can't sue for damages. Practically all software + licences contain this condition. + +Notice that you don't have to provide source code for anything that contains +Python or is built with it. Also, the Python interpreter and accompanying +documentation can be modified and redistributed in any way you like, and you +don't have to pay anyone any licensing fees at all. + +**Why should we use an obscure language like Python instead of well-known +language X?** + +I hope this HOWTO, and the documents listed in the final section, will help +convince you that Python isn't obscure, and has a healthily growing user base. +One word of advice: always present Python's positive advantages, instead of +concentrating on language X's failings. People want to know why a solution is +good, rather than why all the other solutions are bad. So instead of attacking +a competing solution on various grounds, simply show how Python's virtues can +help. + + +Useful Resources +================ + +http://www.pythonology.com/success + The Python Success Stories are a collection of stories from successful users of + Python, with the emphasis on business and corporate users. + +.. % \term{\url{http://www.fsbassociates.com/books/pythonchpt1.htm}} +.. % The first chapter of \emph{Internet Programming with Python} also +.. % examines some of the reasons for using Python. The book is well worth +.. % buying, but the publishers have made the first chapter available on +.. % the Web. + +http://home.pacbell.net/ouster/scripting.html + John Ousterhout's white paper on scripting is a good argument for the utility of + scripting languages, though naturally enough, he emphasizes Tcl, the language he + developed. Most of the arguments would apply to any scripting language. + +http://www.python.org/workshops/1997-10/proceedings/beazley.html + The authors, David M. Beazley and Peter S. Lomdahl, describe their use of + Python at Los Alamos National Laboratory. It's another good example of how + Python can help get real work done. This quotation from the paper has been + echoed by many people: + + .. epigraph:: + + Originally developed as a large monolithic application for massively parallel + processing systems, we have used Python to transform our application into a + flexible, highly modular, and extremely powerful system for performing + simulation, data analysis, and visualization. In addition, we describe how + Python has solved a number of important problems related to the development, + debugging, deployment, and maintenance of scientific software. + +http://pythonjournal.cognizor.com/pyj1/Everitt-Feit_interview98-V1.html + This interview with Andy Feit, discussing Infoseek's use of Python, can be used + to show that choosing Python didn't introduce any difficulties into a company's + development process, and provided some substantial benefits. + +.. % \term{\url{http://www.python.org/psa/Commercial.html}} +.. % Robin Friedrich wrote this document on how to support Python's use in +.. % commercial projects. + +http://www.python.org/workshops/1997-10/proceedings/stein.ps + For the 6th Python conference, Greg Stein presented a paper that traced Python's + adoption and usage at a startup called eShop, and later at Microsoft. + +http://www.opensource.org + Management may be doubtful of the reliability and usefulness of software that + wasn't written commercially. This site presents arguments that show how open + source software can have considerable advantages over closed-source software. + +http://sunsite.unc.edu/LDP/HOWTO/mini/Advocacy.html + The Linux Advocacy mini-HOWTO was the inspiration for this document, and is also + well worth reading for general suggestions on winning acceptance for a new + technology, such as Linux or Python. In general, you won't make much progress + by simply attacking existing systems and complaining about their inadequacies; + this often ends up looking like unfocused whining. It's much better to point + out some of the many areas where Python is an improvement over other systems. + diff --git a/Doc/howto/curses.rst b/Doc/howto/curses.rst new file mode 100644 index 0000000..e16d07a --- /dev/null +++ b/Doc/howto/curses.rst @@ -0,0 +1,434 @@ +********************************** + Curses Programming with Python +********************************** + +:Author: A.M. Kuchling, Eric S. Raymond +:Release: 2.02 + + +.. topic:: Abstract + + This document describes how to write text-mode programs with Python 2.x, using + the :mod:`curses` extension module to control the display. + + +What is curses? +=============== + +The curses library supplies a terminal-independent screen-painting and +keyboard-handling facility for text-based terminals; such terminals include +VT100s, the Linux console, and the simulated terminal provided by X11 programs +such as xterm and rxvt. Display terminals support various control codes to +perform common operations such as moving the cursor, scrolling the screen, and +erasing areas. Different terminals use widely differing codes, and often have +their own minor quirks. + +In a world of X displays, one might ask "why bother"? It's true that +character-cell display terminals are an obsolete technology, but there are +niches in which being able to do fancy things with them are still valuable. One +is on small-footprint or embedded Unixes that don't carry an X server. Another +is for tools like OS installers and kernel configurators that may have to run +before X is available. + +The curses library hides all the details of different terminals, and provides +the programmer with an abstraction of a display, containing multiple +non-overlapping windows. The contents of a window can be changed in various +ways-- adding text, erasing it, changing its appearance--and the curses library +will automagically figure out what control codes need to be sent to the terminal +to produce the right output. + +The curses library was originally written for BSD Unix; the later System V +versions of Unix from AT&T added many enhancements and new functions. BSD curses +is no longer maintained, having been replaced by ncurses, which is an +open-source implementation of the AT&T interface. If you're using an +open-source Unix such as Linux or FreeBSD, your system almost certainly uses +ncurses. Since most current commercial Unix versions are based on System V +code, all the functions described here will probably be available. The older +versions of curses carried by some proprietary Unixes may not support +everything, though. + +No one has made a Windows port of the curses module. On a Windows platform, try +the Console module written by Fredrik Lundh. The Console module provides +cursor-addressable text output, plus full support for mouse and keyboard input, +and is available from http://effbot.org/efflib/console. + + +The Python curses module +------------------------ + +Thy Python module is a fairly simple wrapper over the C functions provided by +curses; if you're already familiar with curses programming in C, it's really +easy to transfer that knowledge to Python. The biggest difference is that the +Python interface makes things simpler, by merging different C functions such as +:func:`addstr`, :func:`mvaddstr`, :func:`mvwaddstr`, into a single +:meth:`addstr` method. You'll see this covered in more detail later. + +This HOWTO is simply an introduction to writing text-mode programs with curses +and Python. It doesn't attempt to be a complete guide to the curses API; for +that, see the Python library guide's section on ncurses, and the C manual pages +for ncurses. It will, however, give you the basic ideas. + + +Starting and ending a curses application +======================================== + +Before doing anything, curses must be initialized. This is done by calling the +:func:`initscr` function, which will determine the terminal type, send any +required setup codes to the terminal, and create various internal data +structures. If successful, :func:`initscr` returns a window object representing +the entire screen; this is usually called ``stdscr``, after the name of the +corresponding C variable. :: + + import curses + stdscr = curses.initscr() + +Usually curses applications turn off automatic echoing of keys to the screen, in +order to be able to read keys and only display them under certain circumstances. +This requires calling the :func:`noecho` function. :: + + curses.noecho() + +Applications will also commonly need to react to keys instantly, without +requiring the Enter key to be pressed; this is called cbreak mode, as opposed to +the usual buffered input mode. :: + + curses.cbreak() + +Terminals usually return special keys, such as the cursor keys or navigation +keys such as Page Up and Home, as a multibyte escape sequence. While you could +write your application to expect such sequences and process them accordingly, +curses can do it for you, returning a special value such as +:const:`curses.KEY_LEFT`. To get curses to do the job, you'll have to enable +keypad mode. :: + + stdscr.keypad(1) + +Terminating a curses application is much easier than starting one. You'll need +to call :: + + curses.nocbreak(); stdscr.keypad(0); curses.echo() + +to reverse the curses-friendly terminal settings. Then call the :func:`endwin` +function to restore the terminal to its original operating mode. :: + + curses.endwin() + +A common problem when debugging a curses application is to get your terminal +messed up when the application dies without restoring the terminal to its +previous state. In Python this commonly happens when your code is buggy and +raises an uncaught exception. Keys are no longer be echoed to the screen when +you type them, for example, which makes using the shell difficult. + +In Python you can avoid these complications and make debugging much easier by +importing the module :mod:`curses.wrapper`. It supplies a :func:`wrapper` +function that takes a callable. It does the initializations described above, +and also initializes colors if color support is present. It then runs your +provided callable and finally deinitializes appropriately. The callable is +called inside a try-catch clause which catches exceptions, performs curses +deinitialization, and then passes the exception upwards. Thus, your terminal +won't be left in a funny state on exception. + + +Windows and Pads +================ + +Windows are the basic abstraction in curses. A window object represents a +rectangular area of the screen, and supports various methods to display text, +erase it, allow the user to input strings, and so forth. + +The ``stdscr`` object returned by the :func:`initscr` function is a window +object that covers the entire screen. Many programs may need only this single +window, but you might wish to divide the screen into smaller windows, in order +to redraw or clear them separately. The :func:`newwin` function creates a new +window of a given size, returning the new window object. :: + + begin_x = 20 ; begin_y = 7 + height = 5 ; width = 40 + win = curses.newwin(height, width, begin_y, begin_x) + +A word about the coordinate system used in curses: coordinates are always passed +in the order *y,x*, and the top-left corner of a window is coordinate (0,0). +This breaks a common convention for handling coordinates, where the *x* +coordinate usually comes first. This is an unfortunate difference from most +other computer applications, but it's been part of curses since it was first +written, and it's too late to change things now. + +When you call a method to display or erase text, the effect doesn't immediately +show up on the display. This is because curses was originally written with slow +300-baud terminal connections in mind; with these terminals, minimizing the time +required to redraw the screen is very important. This lets curses accumulate +changes to the screen, and display them in the most efficient manner. For +example, if your program displays some characters in a window, and then clears +the window, there's no need to send the original characters because they'd never +be visible. + +Accordingly, curses requires that you explicitly tell it to redraw windows, +using the :func:`refresh` method of window objects. In practice, this doesn't +really complicate programming with curses much. Most programs go into a flurry +of activity, and then pause waiting for a keypress or some other action on the +part of the user. All you have to do is to be sure that the screen has been +redrawn before pausing to wait for user input, by simply calling +``stdscr.refresh()`` or the :func:`refresh` method of some other relevant +window. + +A pad is a special case of a window; it can be larger than the actual display +screen, and only a portion of it displayed at a time. Creating a pad simply +requires the pad's height and width, while refreshing a pad requires giving the +coordinates of the on-screen area where a subsection of the pad will be +displayed. :: + + pad = curses.newpad(100, 100) + # These loops fill the pad with letters; this is + # explained in the next section + for y in range(0, 100): + for x in range(0, 100): + try: pad.addch(y,x, ord('a') + (x*x+y*y) % 26 ) + except curses.error: pass + + # Displays a section of the pad in the middle of the screen + pad.refresh( 0,0, 5,5, 20,75) + +The :func:`refresh` call displays a section of the pad in the rectangle +extending from coordinate (5,5) to coordinate (20,75) on the screen; the upper +left corner of the displayed section is coordinate (0,0) on the pad. Beyond +that difference, pads are exactly like ordinary windows and support the same +methods. + +If you have multiple windows and pads on screen there is a more efficient way to +go, which will prevent annoying screen flicker at refresh time. Use the +:meth:`noutrefresh` method of each window to update the data structure +representing the desired state of the screen; then change the physical screen to +match the desired state in one go with the function :func:`doupdate`. The +normal :meth:`refresh` method calls :func:`doupdate` as its last act. + + +Displaying Text +=============== + +From a C programmer's point of view, curses may sometimes look like a twisty +maze of functions, all subtly different. For example, :func:`addstr` displays a +string at the current cursor location in the ``stdscr`` window, while +:func:`mvaddstr` moves to a given y,x coordinate first before displaying the +string. :func:`waddstr` is just like :func:`addstr`, but allows specifying a +window to use, instead of using ``stdscr`` by default. :func:`mvwaddstr` follows +similarly. + +Fortunately the Python interface hides all these details; ``stdscr`` is a window +object like any other, and methods like :func:`addstr` accept multiple argument +forms. Usually there are four different forms. + ++---------------------------------+-----------------------------------------------+ +| Form | Description | ++=================================+===============================================+ +| *str* or *ch* | Display the string *str* or character *ch* at | +| | the current position | ++---------------------------------+-----------------------------------------------+ +| *str* or *ch*, *attr* | Display the string *str* or character *ch*, | +| | using attribute *attr* at the current | +| | position | ++---------------------------------+-----------------------------------------------+ +| *y*, *x*, *str* or *ch* | Move to position *y,x* within the window, and | +| | display *str* or *ch* | ++---------------------------------+-----------------------------------------------+ +| *y*, *x*, *str* or *ch*, *attr* | Move to position *y,x* within the window, and | +| | display *str* or *ch*, using attribute *attr* | ++---------------------------------+-----------------------------------------------+ + +Attributes allow displaying text in highlighted forms, such as in boldface, +underline, reverse code, or in color. They'll be explained in more detail in +the next subsection. + +The :func:`addstr` function takes a Python string as the value to be displayed, +while the :func:`addch` functions take a character, which can be either a Python +string of length 1 or an integer. If it's a string, you're limited to +displaying characters between 0 and 255. SVr4 curses provides constants for +extension characters; these constants are integers greater than 255. For +example, :const:`ACS_PLMINUS` is a +/- symbol, and :const:`ACS_ULCORNER` is the +upper left corner of a box (handy for drawing borders). + +Windows remember where the cursor was left after the last operation, so if you +leave out the *y,x* coordinates, the string or character will be displayed +wherever the last operation left off. You can also move the cursor with the +``move(y,x)`` method. Because some terminals always display a flashing cursor, +you may want to ensure that the cursor is positioned in some location where it +won't be distracting; it can be confusing to have the cursor blinking at some +apparently random location. + +If your application doesn't need a blinking cursor at all, you can call +``curs_set(0)`` to make it invisible. Equivalently, and for compatibility with +older curses versions, there's a ``leaveok(bool)`` function. When *bool* is +true, the curses library will attempt to suppress the flashing cursor, and you +won't need to worry about leaving it in odd locations. + + +Attributes and Color +-------------------- + +Characters can be displayed in different ways. Status lines in a text-based +application are commonly shown in reverse video; a text viewer may need to +highlight certain words. curses supports this by allowing you to specify an +attribute for each cell on the screen. + +An attribute is a integer, each bit representing a different attribute. You can +try to display text with multiple attribute bits set, but curses doesn't +guarantee that all the possible combinations are available, or that they're all +visually distinct. That depends on the ability of the terminal being used, so +it's safest to stick to the most commonly available attributes, listed here. + ++----------------------+--------------------------------------+ +| Attribute | Description | ++======================+======================================+ +| :const:`A_BLINK` | Blinking text | ++----------------------+--------------------------------------+ +| :const:`A_BOLD` | Extra bright or bold text | ++----------------------+--------------------------------------+ +| :const:`A_DIM` | Half bright text | ++----------------------+--------------------------------------+ +| :const:`A_REVERSE` | Reverse-video text | ++----------------------+--------------------------------------+ +| :const:`A_STANDOUT` | The best highlighting mode available | ++----------------------+--------------------------------------+ +| :const:`A_UNDERLINE` | Underlined text | ++----------------------+--------------------------------------+ + +So, to display a reverse-video status line on the top line of the screen, you +could code:: + + stdscr.addstr(0, 0, "Current mode: Typing mode", + curses.A_REVERSE) + stdscr.refresh() + +The curses library also supports color on those terminals that provide it, The +most common such terminal is probably the Linux console, followed by color +xterms. + +To use color, you must call the :func:`start_color` function soon after calling +:func:`initscr`, to initialize the default color set (the +:func:`curses.wrapper.wrapper` function does this automatically). Once that's +done, the :func:`has_colors` function returns TRUE if the terminal in use can +actually display color. (Note: curses uses the American spelling 'color', +instead of the Canadian/British spelling 'colour'. If you're used to the +British spelling, you'll have to resign yourself to misspelling it for the sake +of these functions.) + +The curses library maintains a finite number of color pairs, containing a +foreground (or text) color and a background color. You can get the attribute +value corresponding to a color pair with the :func:`color_pair` function; this +can be bitwise-OR'ed with other attributes such as :const:`A_REVERSE`, but +again, such combinations are not guaranteed to work on all terminals. + +An example, which displays a line of text using color pair 1:: + + stdscr.addstr( "Pretty text", curses.color_pair(1) ) + stdscr.refresh() + +As I said before, a color pair consists of a foreground and background color. +:func:`start_color` initializes 8 basic colors when it activates color mode. +They are: 0:black, 1:red, 2:green, 3:yellow, 4:blue, 5:magenta, 6:cyan, and +7:white. The curses module defines named constants for each of these colors: +:const:`curses.COLOR_BLACK`, :const:`curses.COLOR_RED`, and so forth. + +The ``init_pair(n, f, b)`` function changes the definition of color pair *n*, to +foreground color f and background color b. Color pair 0 is hard-wired to white +on black, and cannot be changed. + +Let's put all this together. To change color 1 to red text on a white +background, you would call:: + + curses.init_pair(1, curses.COLOR_RED, curses.COLOR_WHITE) + +When you change a color pair, any text already displayed using that color pair +will change to the new colors. You can also display new text in this color +with:: + + stdscr.addstr(0,0, "RED ALERT!", curses.color_pair(1) ) + +Very fancy terminals can change the definitions of the actual colors to a given +RGB value. This lets you change color 1, which is usually red, to purple or +blue or any other color you like. Unfortunately, the Linux console doesn't +support this, so I'm unable to try it out, and can't provide any examples. You +can check if your terminal can do this by calling :func:`can_change_color`, +which returns TRUE if the capability is there. If you're lucky enough to have +such a talented terminal, consult your system's man pages for more information. + + +User Input +========== + +The curses library itself offers only very simple input mechanisms. Python's +support adds a text-input widget that makes up some of the lack. + +The most common way to get input to a window is to use its :meth:`getch` method. +:meth:`getch` pauses and waits for the user to hit a key, displaying it if +:func:`echo` has been called earlier. You can optionally specify a coordinate +to which the cursor should be moved before pausing. + +It's possible to change this behavior with the method :meth:`nodelay`. After +``nodelay(1)``, :meth:`getch` for the window becomes non-blocking and returns +``curses.ERR`` (a value of -1) when no input is ready. There's also a +:func:`halfdelay` function, which can be used to (in effect) set a timer on each +:meth:`getch`; if no input becomes available within the number of milliseconds +specified as the argument to :func:`halfdelay`, curses raises an exception. + +The :meth:`getch` method returns an integer; if it's between 0 and 255, it +represents the ASCII code of the key pressed. Values greater than 255 are +special keys such as Page Up, Home, or the cursor keys. You can compare the +value returned to constants such as :const:`curses.KEY_PPAGE`, +:const:`curses.KEY_HOME`, or :const:`curses.KEY_LEFT`. Usually the main loop of +your program will look something like this:: + + while 1: + c = stdscr.getch() + if c == ord('p'): PrintDocument() + elif c == ord('q'): break # Exit the while() + elif c == curses.KEY_HOME: x = y = 0 + +The :mod:`curses.ascii` module supplies ASCII class membership functions that +take either integer or 1-character-string arguments; these may be useful in +writing more readable tests for your command interpreters. It also supplies +conversion functions that take either integer or 1-character-string arguments +and return the same type. For example, :func:`curses.ascii.ctrl` returns the +control character corresponding to its argument. + +There's also a method to retrieve an entire string, :const:`getstr()`. It isn't +used very often, because its functionality is quite limited; the only editing +keys available are the backspace key and the Enter key, which terminates the +string. It can optionally be limited to a fixed number of characters. :: + + curses.echo() # Enable echoing of characters + + # Get a 15-character string, with the cursor on the top line + s = stdscr.getstr(0,0, 15) + +The Python :mod:`curses.textpad` module supplies something better. With it, you +can turn a window into a text box that supports an Emacs-like set of +keybindings. Various methods of :class:`Textbox` class support editing with +input validation and gathering the edit results either with or without trailing +spaces. See the library documentation on :mod:`curses.textpad` for the +details. + + +For More Information +==================== + +This HOWTO didn't cover some advanced topics, such as screen-scraping or +capturing mouse events from an xterm instance. But the Python library page for +the curses modules is now pretty complete. You should browse it next. + +If you're in doubt about the detailed behavior of any of the ncurses entry +points, consult the manual pages for your curses implementation, whether it's +ncurses or a proprietary Unix vendor's. The manual pages will document any +quirks, and provide complete lists of all the functions, attributes, and +:const:`ACS_\*` characters available to you. + +Because the curses API is so large, some functions aren't supported in the +Python interface, not because they're difficult to implement, but because no one +has needed them yet. Feel free to add them and then submit a patch. Also, we +don't yet have support for the menus or panels libraries associated with +ncurses; feel free to add that. + +If you write an interesting little program, feel free to contribute it as +another demo. We can always use more of them! + +The ncurses FAQ: http://dickey.his.com/ncurses/ncurses.faq.html + diff --git a/Doc/howto/doanddont.rst b/Doc/howto/doanddont.rst new file mode 100644 index 0000000..a322c53 --- /dev/null +++ b/Doc/howto/doanddont.rst @@ -0,0 +1,308 @@ +************************************ + Idioms and Anti-Idioms in Python +************************************ + +:Author: Moshe Zadka + +This document is placed in the public doman. + + +.. topic:: Abstract + + This document can be considered a companion to the tutorial. It shows how to use + Python, and even more importantly, how *not* to use Python. + + +Language Constructs You Should Not Use +====================================== + +While Python has relatively few gotchas compared to other languages, it still +has some constructs which are only useful in corner cases, or are plain +dangerous. + + +from module import \* +--------------------- + + +Inside Function Definitions +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +``from module import *`` is *invalid* inside function definitions. While many +versions of Python do not check for the invalidity, it does not make it more +valid, no more then having a smart lawyer makes a man innocent. Do not use it +like that ever. Even in versions where it was accepted, it made the function +execution slower, because the compiler could not be certain which names are +local and which are global. In Python 2.1 this construct causes warnings, and +sometimes even errors. + + +At Module Level +^^^^^^^^^^^^^^^ + +While it is valid to use ``from module import *`` at module level it is usually +a bad idea. For one, this loses an important property Python otherwise has --- +you can know where each toplevel name is defined by a simple "search" function +in your favourite editor. You also open yourself to trouble in the future, if +some module grows additional functions or classes. + +One of the most awful question asked on the newsgroup is why this code:: + + f = open("www") + f.read() + +does not work. Of course, it works just fine (assuming you have a file called +"www".) But it does not work if somewhere in the module, the statement ``from os +import *`` is present. The :mod:`os` module has a function called :func:`open` +which returns an integer. While it is very useful, shadowing builtins is one of +its least useful properties. + +Remember, you can never know for sure what names a module exports, so either +take what you need --- ``from module import name1, name2``, or keep them in the +module and access on a per-need basis --- ``import module;print module.name``. + + +When It Is Just Fine +^^^^^^^^^^^^^^^^^^^^ + +There are situations in which ``from module import *`` is just fine: + +* The interactive prompt. For example, ``from math import *`` makes Python an + amazing scientific calculator. + +* When extending a module in C with a module in Python. + +* When the module advertises itself as ``from import *`` safe. + + +Unadorned :keyword:`exec` and friends +------------------------------------- + +The word "unadorned" refers to the use without an explicit dictionary, in which +case those constructs evaluate code in the *current* environment. This is +dangerous for the same reasons ``from import *`` is dangerous --- it might step +over variables you are counting on and mess up things for the rest of your code. +Simply do not do that. + +Bad examples:: + + >>> for name in sys.argv[1:]: + >>> exec "%s=1" % name + >>> def func(s, **kw): + >>> for var, val in kw.items(): + >>> exec "s.%s=val" % var # invalid! + >>> exec(open("handler.py").read()) + >>> handle() + +Good examples:: + + >>> d = {} + >>> for name in sys.argv[1:]: + >>> d[name] = 1 + >>> def func(s, **kw): + >>> for var, val in kw.items(): + >>> setattr(s, var, val) + >>> d={} + >>> exec(open("handle.py").read(), d, d) + >>> handle = d['handle'] + >>> handle() + + +from module import name1, name2 +------------------------------- + +This is a "don't" which is much weaker then the previous "don't"s but is still +something you should not do if you don't have good reasons to do that. The +reason it is usually bad idea is because you suddenly have an object which lives +in two seperate namespaces. When the binding in one namespace changes, the +binding in the other will not, so there will be a discrepancy between them. This +happens when, for example, one module is reloaded, or changes the definition of +a function at runtime. + +Bad example:: + + # foo.py + a = 1 + + # bar.py + from foo import a + if something(): + a = 2 # danger: foo.a != a + +Good example:: + + # foo.py + a = 1 + + # bar.py + import foo + if something(): + foo.a = 2 + + +except: +------- + +Python has the ``except:`` clause, which catches all exceptions. Since *every* +error in Python raises an exception, this makes many programming errors look +like runtime problems, and hinders the debugging process. + +The following code shows a great example:: + + try: + foo = opne("file") # misspelled "open" + except: + sys.exit("could not open file!") + +The second line triggers a :exc:`NameError` which is caught by the except +clause. The program will exit, and you will have no idea that this has nothing +to do with the readability of ``"file"``. + +The example above is better written :: + + try: + foo = opne("file") # will be changed to "open" as soon as we run it + except IOError: + sys.exit("could not open file") + +There are some situations in which the ``except:`` clause is useful: for +example, in a framework when running callbacks, it is good not to let any +callback disturb the framework. + + +Exceptions +========== + +Exceptions are a useful feature of Python. You should learn to raise them +whenever something unexpected occurs, and catch them only where you can do +something about them. + +The following is a very popular anti-idiom :: + + def get_status(file): + if not os.path.exists(file): + print "file not found" + sys.exit(1) + return open(file).readline() + +Consider the case the file gets deleted between the time the call to +:func:`os.path.exists` is made and the time :func:`open` is called. That means +the last line will throw an :exc:`IOError`. The same would happen if *file* +exists but has no read permission. Since testing this on a normal machine on +existing and non-existing files make it seem bugless, that means in testing the +results will seem fine, and the code will get shipped. Then an unhandled +:exc:`IOError` escapes to the user, who has to watch the ugly traceback. + +Here is a better way to do it. :: + + def get_status(file): + try: + return open(file).readline() + except (IOError, OSError): + print "file not found" + sys.exit(1) + +In this version, \*either\* the file gets opened and the line is read (so it +works even on flaky NFS or SMB connections), or the message is printed and the +application aborted. + +Still, :func:`get_status` makes too many assumptions --- that it will only be +used in a short running script, and not, say, in a long running server. Sure, +the caller could do something like :: + + try: + status = get_status(log) + except SystemExit: + status = None + +So, try to make as few ``except`` clauses in your code --- those will usually be +a catch-all in the :func:`main`, or inside calls which should always succeed. + +So, the best version is probably :: + + def get_status(file): + return open(file).readline() + +The caller can deal with the exception if it wants (for example, if it tries +several files in a loop), or just let the exception filter upwards to *its* +caller. + +The last version is not very good either --- due to implementation details, the +file would not be closed when an exception is raised until the handler finishes, +and perhaps not at all in non-C implementations (e.g., Jython). :: + + def get_status(file): + fp = open(file) + try: + return fp.readline() + finally: + fp.close() + + +Using the Batteries +=================== + +Every so often, people seem to be writing stuff in the Python library again, +usually poorly. While the occasional module has a poor interface, it is usually +much better to use the rich standard library and data types that come with +Python then inventing your own. + +A useful module very few people know about is :mod:`os.path`. It always has the +correct path arithmetic for your operating system, and will usually be much +better then whatever you come up with yourself. + +Compare:: + + # ugh! + return dir+"/"+file + # better + return os.path.join(dir, file) + +More useful functions in :mod:`os.path`: :func:`basename`, :func:`dirname` and +:func:`splitext`. + +There are also many useful builtin functions people seem not to be aware of for +some reason: :func:`min` and :func:`max` can find the minimum/maximum of any +sequence with comparable semantics, for example, yet many people write their own +:func:`max`/:func:`min`. Another highly useful function is :func:`reduce`. A +classical use of :func:`reduce` is something like :: + + import sys, operator + nums = map(float, sys.argv[1:]) + print reduce(operator.add, nums)/len(nums) + +This cute little script prints the average of all numbers given on the command +line. The :func:`reduce` adds up all the numbers, and the rest is just some +pre- and postprocessing. + +On the same note, note that :func:`float`, :func:`int` and :func:`long` all +accept arguments of type string, and so are suited to parsing --- assuming you +are ready to deal with the :exc:`ValueError` they raise. + + +Using Backslash to Continue Statements +====================================== + +Since Python treats a newline as a statement terminator, and since statements +are often more then is comfortable to put in one line, many people do:: + + if foo.bar()['first'][0] == baz.quux(1, 2)[5:9] and \ + calculate_number(10, 20) != forbulate(500, 360): + pass + +You should realize that this is dangerous: a stray space after the ``XXX`` would +make this line wrong, and stray spaces are notoriously hard to see in editors. +In this case, at least it would be a syntax error, but if the code was:: + + value = foo.bar()['first'][0]*baz.quux(1, 2)[5:9] \ + + calculate_number(10, 20)*forbulate(500, 360) + +then it would just be subtly wrong. + +It is usually much better to use the implicit continuation inside parenthesis: + +This version is bulletproof:: + + value = (foo.bar()['first'][0]*baz.quux(1, 2)[5:9] + + calculate_number(10, 20)*forbulate(500, 360)) + diff --git a/Doc/howto/functional.rst b/Doc/howto/functional.rst new file mode 100644 index 0000000..bc12793 --- /dev/null +++ b/Doc/howto/functional.rst @@ -0,0 +1,1400 @@ +******************************** + Functional Programming HOWTO +******************************** + +:Author: \A. M. Kuchling +:Release: 0.30 + +(This is a first draft. Please send comments/error reports/suggestions to +amk@amk.ca. This URL is probably not going to be the final location of the +document, so be careful about linking to it -- you may want to add a +disclaimer.) + +In this document, we'll take a tour of Python's features suitable for +implementing programs in a functional style. After an introduction to the +concepts of functional programming, we'll look at language features such as +iterators and generators and relevant library modules such as :mod:`itertools` +and :mod:`functools`. + + +Introduction +============ + +This section explains the basic concept of functional programming; if you're +just interested in learning about Python language features, skip to the next +section. + +Programming languages support decomposing problems in several different ways: + +* Most programming languages are **procedural**: programs are lists of + instructions that tell the computer what to do with the program's input. C, + Pascal, and even Unix shells are procedural languages. + +* In **declarative** languages, you write a specification that describes the + problem to be solved, and the language implementation figures out how to + perform the computation efficiently. SQL is the declarative language you're + most likely to be familiar with; a SQL query describes the data set you want + to retrieve, and the SQL engine decides whether to scan tables or use indexes, + which subclauses should be performed first, etc. + +* **Object-oriented** programs manipulate collections of objects. Objects have + internal state and support methods that query or modify this internal state in + some way. Smalltalk and Java are object-oriented languages. C++ and Python + are languages that support object-oriented programming, but don't force the + use of object-oriented features. + +* **Functional** programming decomposes a problem into a set of functions. + Ideally, functions only take inputs and produce outputs, and don't have any + internal state that affects the output produced for a given input. Well-known + functional languages include the ML family (Standard ML, OCaml, and other + variants) and Haskell. + +The designers of some computer languages have chosen one approach to programming +that's emphasized. This often makes it difficult to write programs that use a +different approach. Other languages are multi-paradigm languages that support +several different approaches. Lisp, C++, and Python are multi-paradigm; you can +write programs or libraries that are largely procedural, object-oriented, or +functional in all of these languages. In a large program, different sections +might be written using different approaches; the GUI might be object-oriented +while the processing logic is procedural or functional, for example. + +In a functional program, input flows through a set of functions. Each function +operates on its input and produces some output. Functional style frowns upon +functions with side effects that modify internal state or make other changes +that aren't visible in the function's return value. Functions that have no side +effects at all are called **purely functional**. Avoiding side effects means +not using data structures that get updated as a program runs; every function's +output must only depend on its input. + +Some languages are very strict about purity and don't even have assignment +statements such as ``a=3`` or ``c = a + b``, but it's difficult to avoid all +side effects. Printing to the screen or writing to a disk file are side +effects, for example. For example, in Python a ``print`` statement or a +``time.sleep(1)`` both return no useful value; they're only called for their +side effects of sending some text to the screen or pausing execution for a +second. + +Python programs written in functional style usually won't go to the extreme of +avoiding all I/O or all assignments; instead, they'll provide a +functional-appearing interface but will use non-functional features internally. +For example, the implementation of a function will still use assignments to +local variables, but won't modify global variables or have other side effects. + +Functional programming can be considered the opposite of object-oriented +programming. Objects are little capsules containing some internal state along +with a collection of method calls that let you modify this state, and programs +consist of making the right set of state changes. Functional programming wants +to avoid state changes as much as possible and works with data flowing between +functions. In Python you might combine the two approaches by writing functions +that take and return instances representing objects in your application (e-mail +messages, transactions, etc.). + +Functional design may seem like an odd constraint to work under. Why should you +avoid objects and side effects? There are theoretical and practical advantages +to the functional style: + +* Formal provability. +* Modularity. +* Composability. +* Ease of debugging and testing. + +Formal provability +------------------ + +A theoretical benefit is that it's easier to construct a mathematical proof that +a functional program is correct. + +For a long time researchers have been interested in finding ways to +mathematically prove programs correct. This is different from testing a program +on numerous inputs and concluding that its output is usually correct, or reading +a program's source code and concluding that the code looks right; the goal is +instead a rigorous proof that a program produces the right result for all +possible inputs. + +The technique used to prove programs correct is to write down **invariants**, +properties of the input data and of the program's variables that are always +true. For each line of code, you then show that if invariants X and Y are true +**before** the line is executed, the slightly different invariants X' and Y' are +true **after** the line is executed. This continues until you reach the end of +the program, at which point the invariants should match the desired conditions +on the program's output. + +Functional programming's avoidance of assignments arose because assignments are +difficult to handle with this technique; assignments can break invariants that +were true before the assignment without producing any new invariants that can be +propagated onward. + +Unfortunately, proving programs correct is largely impractical and not relevant +to Python software. Even trivial programs require proofs that are several pages +long; the proof of correctness for a moderately complicated program would be +enormous, and few or none of the programs you use daily (the Python interpreter, +your XML parser, your web browser) could be proven correct. Even if you wrote +down or generated a proof, there would then be the question of verifying the +proof; maybe there's an error in it, and you wrongly believe you've proved the +program correct. + +Modularity +---------- + +A more practical benefit of functional programming is that it forces you to +break apart your problem into small pieces. Programs are more modular as a +result. It's easier to specify and write a small function that does one thing +than a large function that performs a complicated transformation. Small +functions are also easier to read and to check for errors. + + +Ease of debugging and testing +----------------------------- + +Testing and debugging a functional-style program is easier. + +Debugging is simplified because functions are generally small and clearly +specified. When a program doesn't work, each function is an interface point +where you can check that the data are correct. You can look at the intermediate +inputs and outputs to quickly isolate the function that's responsible for a bug. + +Testing is easier because each function is a potential subject for a unit test. +Functions don't depend on system state that needs to be replicated before +running a test; instead you only have to synthesize the right input and then +check that the output matches expectations. + + + +Composability +------------- + +As you work on a functional-style program, you'll write a number of functions +with varying inputs and outputs. Some of these functions will be unavoidably +specialized to a particular application, but others will be useful in a wide +variety of programs. For example, a function that takes a directory path and +returns all the XML files in the directory, or a function that takes a filename +and returns its contents, can be applied to many different situations. + +Over time you'll form a personal library of utilities. Often you'll assemble +new programs by arranging existing functions in a new configuration and writing +a few functions specialized for the current task. + + + +Iterators +========= + +I'll start by looking at a Python language feature that's an important +foundation for writing functional-style programs: iterators. + +An iterator is an object representing a stream of data; this object returns the +data one element at a time. A Python iterator must support a method called +``next()`` that takes no arguments and always returns the next element of the +stream. If there are no more elements in the stream, ``next()`` must raise the +``StopIteration`` exception. Iterators don't have to be finite, though; it's +perfectly reasonable to write an iterator that produces an infinite stream of +data. + +The built-in :func:`iter` function takes an arbitrary object and tries to return +an iterator that will return the object's contents or elements, raising +:exc:`TypeError` if the object doesn't support iteration. Several of Python's +built-in data types support iteration, the most common being lists and +dictionaries. An object is called an **iterable** object if you can get an +iterator for it. + +You can experiment with the iteration interface manually:: + + >>> L = [1,2,3] + >>> it = iter(L) + >>> print it + + >>> it.next() + 1 + >>> it.next() + 2 + >>> it.next() + 3 + >>> it.next() + Traceback (most recent call last): + File "", line 1, in ? + StopIteration + >>> + +Python expects iterable objects in several different contexts, the most +important being the ``for`` statement. In the statement ``for X in Y``, Y must +be an iterator or some object for which ``iter()`` can create an iterator. +These two statements are equivalent:: + + for i in iter(obj): + print i + + for i in obj: + print i + +Iterators can be materialized as lists or tuples by using the :func:`list` or +:func:`tuple` constructor functions:: + + >>> L = [1,2,3] + >>> iterator = iter(L) + >>> t = tuple(iterator) + >>> t + (1, 2, 3) + +Sequence unpacking also supports iterators: if you know an iterator will return +N elements, you can unpack them into an N-tuple:: + + >>> L = [1,2,3] + >>> iterator = iter(L) + >>> a,b,c = iterator + >>> a,b,c + (1, 2, 3) + +Built-in functions such as :func:`max` and :func:`min` can take a single +iterator argument and will return the largest or smallest element. The ``"in"`` +and ``"not in"`` operators also support iterators: ``X in iterator`` is true if +X is found in the stream returned by the iterator. You'll run into obvious +problems if the iterator is infinite; ``max()``, ``min()``, and ``"not in"`` +will never return, and if the element X never appears in the stream, the +``"in"`` operator won't return either. + +Note that you can only go forward in an iterator; there's no way to get the +previous element, reset the iterator, or make a copy of it. Iterator objects +can optionally provide these additional capabilities, but the iterator protocol +only specifies the ``next()`` method. Functions may therefore consume all of +the iterator's output, and if you need to do something different with the same +stream, you'll have to create a new iterator. + + + +Data Types That Support Iterators +--------------------------------- + +We've already seen how lists and tuples support iterators. In fact, any Python +sequence type, such as strings, will automatically support creation of an +iterator. + +Calling :func:`iter` on a dictionary returns an iterator that will loop over the +dictionary's keys:: + + >>> m = {'Jan': 1, 'Feb': 2, 'Mar': 3, 'Apr': 4, 'May': 5, 'Jun': 6, + ... 'Jul': 7, 'Aug': 8, 'Sep': 9, 'Oct': 10, 'Nov': 11, 'Dec': 12} + >>> for key in m: + ... print key, m[key] + Mar 3 + Feb 2 + Aug 8 + Sep 9 + May 5 + Jun 6 + Jul 7 + Jan 1 + Apr 4 + Nov 11 + Dec 12 + Oct 10 + +Note that the order is essentially random, because it's based on the hash +ordering of the objects in the dictionary. + +Applying ``iter()`` to a dictionary always loops over the keys, but dictionaries +have methods that return other iterators. If you want to iterate over keys, +values, or key/value pairs, you can explicitly call the ``iterkeys()``, +``itervalues()``, or ``iteritems()`` methods to get an appropriate iterator. + +The :func:`dict` constructor can accept an iterator that returns a finite stream +of ``(key, value)`` tuples:: + + >>> L = [('Italy', 'Rome'), ('France', 'Paris'), ('US', 'Washington DC')] + >>> dict(iter(L)) + {'Italy': 'Rome', 'US': 'Washington DC', 'France': 'Paris'} + +Files also support iteration by calling the ``readline()`` method until there +are no more lines in the file. This means you can read each line of a file like +this:: + + for line in file: + # do something for each line + ... + +Sets can take their contents from an iterable and let you iterate over the set's +elements:: + + S = set((2, 3, 5, 7, 11, 13)) + for i in S: + print i + + + +Generator expressions and list comprehensions +============================================= + +Two common operations on an iterator's output are 1) performing some operation +for every element, 2) selecting a subset of elements that meet some condition. +For example, given a list of strings, you might want to strip off trailing +whitespace from each line or extract all the strings containing a given +substring. + +List comprehensions and generator expressions (short form: "listcomps" and +"genexps") are a concise notation for such operations, borrowed from the +functional programming language Haskell (http://www.haskell.org). You can strip +all the whitespace from a stream of strings with the following code:: + + line_list = [' line 1\n', 'line 2 \n', ...] + + # Generator expression -- returns iterator + stripped_iter = (line.strip() for line in line_list) + + # List comprehension -- returns list + stripped_list = [line.strip() for line in line_list] + +You can select only certain elements by adding an ``"if"`` condition:: + + stripped_list = [line.strip() for line in line_list + if line != ""] + +With a list comprehension, you get back a Python list; ``stripped_list`` is a +list containing the resulting lines, not an iterator. Generator expressions +return an iterator that computes the values as necessary, not needing to +materialize all the values at once. This means that list comprehensions aren't +useful if you're working with iterators that return an infinite stream or a very +large amount of data. Generator expressions are preferable in these situations. + +Generator expressions are surrounded by parentheses ("()") and list +comprehensions are surrounded by square brackets ("[]"). Generator expressions +have the form:: + + ( expression for expr in sequence1 + if condition1 + for expr2 in sequence2 + if condition2 + for expr3 in sequence3 ... + if condition3 + for exprN in sequenceN + if conditionN ) + +Again, for a list comprehension only the outside brackets are different (square +brackets instead of parentheses). + +The elements of the generated output will be the successive values of +``expression``. The ``if`` clauses are all optional; if present, ``expression`` +is only evaluated and added to the result when ``condition`` is true. + +Generator expressions always have to be written inside parentheses, but the +parentheses signalling a function call also count. If you want to create an +iterator that will be immediately passed to a function you can write:: + + obj_total = sum(obj.count for obj in list_all_objects()) + +The ``for...in`` clauses contain the sequences to be iterated over. The +sequences do not have to be the same length, because they are iterated over from +left to right, **not** in parallel. For each element in ``sequence1``, +``sequence2`` is looped over from the beginning. ``sequence3`` is then looped +over for each resulting pair of elements from ``sequence1`` and ``sequence2``. + +To put it another way, a list comprehension or generator expression is +equivalent to the following Python code:: + + for expr1 in sequence1: + if not (condition1): + continue # Skip this element + for expr2 in sequence2: + if not (condition2): + continue # Skip this element + ... + for exprN in sequenceN: + if not (conditionN): + continue # Skip this element + + # Output the value of + # the expression. + +This means that when there are multiple ``for...in`` clauses but no ``if`` +clauses, the length of the resulting output will be equal to the product of the +lengths of all the sequences. If you have two lists of length 3, the output +list is 9 elements long:: + + seq1 = 'abc' + seq2 = (1,2,3) + >>> [ (x,y) for x in seq1 for y in seq2] + [('a', 1), ('a', 2), ('a', 3), + ('b', 1), ('b', 2), ('b', 3), + ('c', 1), ('c', 2), ('c', 3)] + +To avoid introducing an ambiguity into Python's grammar, if ``expression`` is +creating a tuple, it must be surrounded with parentheses. The first list +comprehension below is a syntax error, while the second one is correct:: + + # Syntax error + [ x,y for x in seq1 for y in seq2] + # Correct + [ (x,y) for x in seq1 for y in seq2] + + +Generators +========== + +Generators are a special class of functions that simplify the task of writing +iterators. Regular functions compute a value and return it, but generators +return an iterator that returns a stream of values. + +You're doubtless familiar with how regular function calls work in Python or C. +When you call a function, it gets a private namespace where its local variables +are created. When the function reaches a ``return`` statement, the local +variables are destroyed and the value is returned to the caller. A later call +to the same function creates a new private namespace and a fresh set of local +variables. But, what if the local variables weren't thrown away on exiting a +function? What if you could later resume the function where it left off? This +is what generators provide; they can be thought of as resumable functions. + +Here's the simplest example of a generator function:: + + def generate_ints(N): + for i in range(N): + yield i + +Any function containing a ``yield`` keyword is a generator function; this is +detected by Python's bytecode compiler which compiles the function specially as +a result. + +When you call a generator function, it doesn't return a single value; instead it +returns a generator object that supports the iterator protocol. On executing +the ``yield`` expression, the generator outputs the value of ``i``, similar to a +``return`` statement. The big difference between ``yield`` and a ``return`` +statement is that on reaching a ``yield`` the generator's state of execution is +suspended and local variables are preserved. On the next call to the +generator's ``.next()`` method, the function will resume executing. + +Here's a sample usage of the ``generate_ints()`` generator:: + + >>> gen = generate_ints(3) + >>> gen + + >>> gen.next() + 0 + >>> gen.next() + 1 + >>> gen.next() + 2 + >>> gen.next() + Traceback (most recent call last): + File "stdin", line 1, in ? + File "stdin", line 2, in generate_ints + StopIteration + +You could equally write ``for i in generate_ints(5)``, or ``a,b,c = +generate_ints(3)``. + +Inside a generator function, the ``return`` statement can only be used without a +value, and signals the end of the procession of values; after executing a +``return`` the generator cannot return any further values. ``return`` with a +value, such as ``return 5``, is a syntax error inside a generator function. The +end of the generator's results can also be indicated by raising +``StopIteration`` manually, or by just letting the flow of execution fall off +the bottom of the function. + +You could achieve the effect of generators manually by writing your own class +and storing all the local variables of the generator as instance variables. For +example, returning a list of integers could be done by setting ``self.count`` to +0, and having the ``next()`` method increment ``self.count`` and return it. +However, for a moderately complicated generator, writing a corresponding class +can be much messier. + +The test suite included with Python's library, ``test_generators.py``, contains +a number of more interesting examples. Here's one generator that implements an +in-order traversal of a tree using generators recursively. + +:: + + # A recursive generator that generates Tree leaves in in-order. + def inorder(t): + if t: + for x in inorder(t.left): + yield x + + yield t.label + + for x in inorder(t.right): + yield x + +Two other examples in ``test_generators.py`` produce solutions for the N-Queens +problem (placing N queens on an NxN chess board so that no queen threatens +another) and the Knight's Tour (finding a route that takes a knight to every +square of an NxN chessboard without visiting any square twice). + + + +Passing values into a generator +------------------------------- + +In Python 2.4 and earlier, generators only produced output. Once a generator's +code was invoked to create an iterator, there was no way to pass any new +information into the function when its execution is resumed. You could hack +together this ability by making the generator look at a global variable or by +passing in some mutable object that callers then modify, but these approaches +are messy. + +In Python 2.5 there's a simple way to pass values into a generator. +:keyword:`yield` became an expression, returning a value that can be assigned to +a variable or otherwise operated on:: + + val = (yield i) + +I recommend that you **always** put parentheses around a ``yield`` expression +when you're doing something with the returned value, as in the above example. +The parentheses aren't always necessary, but it's easier to always add them +instead of having to remember when they're needed. + +(PEP 342 explains the exact rules, which are that a ``yield``-expression must +always be parenthesized except when it occurs at the top-level expression on the +right-hand side of an assignment. This means you can write ``val = yield i`` +but have to use parentheses when there's an operation, as in ``val = (yield i) ++ 12``.) + +Values are sent into a generator by calling its ``send(value)`` method. This +method resumes the generator's code and the ``yield`` expression returns the +specified value. If the regular ``next()`` method is called, the ``yield`` +returns ``None``. + +Here's a simple counter that increments by 1 and allows changing the value of +the internal counter. + +:: + + def counter (maximum): + i = 0 + while i < maximum: + val = (yield i) + # If value provided, change counter + if val is not None: + i = val + else: + i += 1 + +And here's an example of changing the counter: + + >>> it = counter(10) + >>> print it.next() + 0 + >>> print it.next() + 1 + >>> print it.send(8) + 8 + >>> print it.next() + 9 + >>> print it.next() + Traceback (most recent call last): + File ``t.py'', line 15, in ? + print it.next() + StopIteration + +Because ``yield`` will often be returning ``None``, you should always check for +this case. Don't just use its value in expressions unless you're sure that the +``send()`` method will be the only method used resume your generator function. + +In addition to ``send()``, there are two other new methods on generators: + +* ``throw(type, value=None, traceback=None)`` is used to raise an exception + inside the generator; the exception is raised by the ``yield`` expression + where the generator's execution is paused. + +* ``close()`` raises a :exc:`GeneratorExit` exception inside the generator to + terminate the iteration. On receiving this exception, the generator's code + must either raise :exc:`GeneratorExit` or :exc:`StopIteration`; catching the + exception and doing anything else is illegal and will trigger a + :exc:`RuntimeError`. ``close()`` will also be called by Python's garbage + collector when the generator is garbage-collected. + + If you need to run cleanup code when a :exc:`GeneratorExit` occurs, I suggest + using a ``try: ... finally:`` suite instead of catching :exc:`GeneratorExit`. + +The cumulative effect of these changes is to turn generators from one-way +producers of information into both producers and consumers. + +Generators also become **coroutines**, a more generalized form of subroutines. +Subroutines are entered at one point and exited at another point (the top of the +function, and a ``return`` statement), but coroutines can be entered, exited, +and resumed at many different points (the ``yield`` statements). + + +Built-in functions +================== + +Let's look in more detail at built-in functions often used with iterators. + +Two Python's built-in functions, :func:`map` and :func:`filter`, are somewhat +obsolete; they duplicate the features of list comprehensions but return actual +lists instead of iterators. + +``map(f, iterA, iterB, ...)`` returns a list containing ``f(iterA[0], iterB[0]), +f(iterA[1], iterB[1]), f(iterA[2], iterB[2]), ...``. + +:: + + def upper(s): + return s.upper() + map(upper, ['sentence', 'fragment']) => + ['SENTENCE', 'FRAGMENT'] + + [upper(s) for s in ['sentence', 'fragment']] => + ['SENTENCE', 'FRAGMENT'] + +As shown above, you can achieve the same effect with a list comprehension. The +:func:`itertools.imap` function does the same thing but can handle infinite +iterators; it'll be discussed later, in the section on the :mod:`itertools` module. + +``filter(predicate, iter)`` returns a list that contains all the sequence +elements that meet a certain condition, and is similarly duplicated by list +comprehensions. A **predicate** is a function that returns the truth value of +some condition; for use with :func:`filter`, the predicate must take a single +value. + +:: + + def is_even(x): + return (x % 2) == 0 + + filter(is_even, range(10)) => + [0, 2, 4, 6, 8] + +This can also be written as a list comprehension:: + + >>> [x for x in range(10) if is_even(x)] + [0, 2, 4, 6, 8] + +:func:`filter` also has a counterpart in the :mod:`itertools` module, +:func:`itertools.ifilter`, that returns an iterator and can therefore handle +infinite sequences just as :func:`itertools.imap` can. + +``reduce(func, iter, [initial_value])`` doesn't have a counterpart in the +:mod:`itertools` module because it cumulatively performs an operation on all the +iterable's elements and therefore can't be applied to infinite iterables. +``func`` must be a function that takes two elements and returns a single value. +:func:`reduce` takes the first two elements A and B returned by the iterator and +calculates ``func(A, B)``. It then requests the third element, C, calculates +``func(func(A, B), C)``, combines this result with the fourth element returned, +and continues until the iterable is exhausted. If the iterable returns no +values at all, a :exc:`TypeError` exception is raised. If the initial value is +supplied, it's used as a starting point and ``func(initial_value, A)`` is the +first calculation. + +:: + + import operator + reduce(operator.concat, ['A', 'BB', 'C']) => + 'ABBC' + reduce(operator.concat, []) => + TypeError: reduce() of empty sequence with no initial value + reduce(operator.mul, [1,2,3], 1) => + 6 + reduce(operator.mul, [], 1) => + 1 + +If you use :func:`operator.add` with :func:`reduce`, you'll add up all the +elements of the iterable. This case is so common that there's a special +built-in called :func:`sum` to compute it:: + + reduce(operator.add, [1,2,3,4], 0) => + 10 + sum([1,2,3,4]) => + 10 + sum([]) => + 0 + +For many uses of :func:`reduce`, though, it can be clearer to just write the +obvious :keyword:`for` loop:: + + # Instead of: + product = reduce(operator.mul, [1,2,3], 1) + + # You can write: + product = 1 + for i in [1,2,3]: + product *= i + + +``enumerate(iter)`` counts off the elements in the iterable, returning 2-tuples +containing the count and each element. + +:: + + enumerate(['subject', 'verb', 'object']) => + (0, 'subject'), (1, 'verb'), (2, 'object') + +:func:`enumerate` is often used when looping through a list and recording the +indexes at which certain conditions are met:: + + f = open('data.txt', 'r') + for i, line in enumerate(f): + if line.strip() == '': + print 'Blank line at line #%i' % i + +``sorted(iterable, [cmp=None], [key=None], [reverse=False)`` collects all the +elements of the iterable into a list, sorts the list, and returns the sorted +result. The ``cmp``, ``key``, and ``reverse`` arguments are passed through to +the constructed list's ``.sort()`` method. + +:: + + import random + # Generate 8 random numbers between [0, 10000) + rand_list = random.sample(range(10000), 8) + rand_list => + [769, 7953, 9828, 6431, 8442, 9878, 6213, 2207] + sorted(rand_list) => + [769, 2207, 6213, 6431, 7953, 8442, 9828, 9878] + sorted(rand_list, reverse=True) => + [9878, 9828, 8442, 7953, 6431, 6213, 2207, 769] + +(For a more detailed discussion of sorting, see the Sorting mini-HOWTO in the +Python wiki at http://wiki.python.org/moin/HowTo/Sorting.) + +The ``any(iter)`` and ``all(iter)`` built-ins look at the truth values of an +iterable's contents. :func:`any` returns True if any element in the iterable is +a true value, and :func:`all` returns True if all of the elements are true +values:: + + any([0,1,0]) => + True + any([0,0,0]) => + False + any([1,1,1]) => + True + all([0,1,0]) => + False + all([0,0,0]) => + False + all([1,1,1]) => + True + + +Small functions and the lambda expression +========================================= + +When writing functional-style programs, you'll often need little functions that +act as predicates or that combine elements in some way. + +If there's a Python built-in or a module function that's suitable, you don't +need to define a new function at all:: + + stripped_lines = [line.strip() for line in lines] + existing_files = filter(os.path.exists, file_list) + +If the function you need doesn't exist, you need to write it. One way to write +small functions is to use the ``lambda`` statement. ``lambda`` takes a number +of parameters and an expression combining these parameters, and creates a small +function that returns the value of the expression:: + + lowercase = lambda x: x.lower() + + print_assign = lambda name, value: name + '=' + str(value) + + adder = lambda x, y: x+y + +An alternative is to just use the ``def`` statement and define a function in the +usual way:: + + def lowercase(x): + return x.lower() + + def print_assign(name, value): + return name + '=' + str(value) + + def adder(x,y): + return x + y + +Which alternative is preferable? That's a style question; my usual course is to +avoid using ``lambda``. + +One reason for my preference is that ``lambda`` is quite limited in the +functions it can define. The result has to be computable as a single +expression, which means you can't have multiway ``if... elif... else`` +comparisons or ``try... except`` statements. If you try to do too much in a +``lambda`` statement, you'll end up with an overly complicated expression that's +hard to read. Quick, what's the following code doing? + +:: + + total = reduce(lambda a, b: (0, a[1] + b[1]), items)[1] + +You can figure it out, but it takes time to disentangle the expression to figure +out what's going on. Using a short nested ``def`` statements makes things a +little bit better:: + + def combine (a, b): + return 0, a[1] + b[1] + + total = reduce(combine, items)[1] + +But it would be best of all if I had simply used a ``for`` loop:: + + total = 0 + for a, b in items: + total += b + +Or the :func:`sum` built-in and a generator expression:: + + total = sum(b for a,b in items) + +Many uses of :func:`reduce` are clearer when written as ``for`` loops. + +Fredrik Lundh once suggested the following set of rules for refactoring uses of +``lambda``: + +1) Write a lambda function. +2) Write a comment explaining what the heck that lambda does. +3) Study the comment for a while, and think of a name that captures the essence + of the comment. +4) Convert the lambda to a def statement, using that name. +5) Remove the comment. + +I really like these rules, but you're free to disagree that this lambda-free +style is better. + + +The itertools module +==================== + +The :mod:`itertools` module contains a number of commonly-used iterators as well +as functions for combining several iterators. This section will introduce the +module's contents by showing small examples. + +The module's functions fall into a few broad classes: + +* Functions that create a new iterator based on an existing iterator. +* Functions for treating an iterator's elements as function arguments. +* Functions for selecting portions of an iterator's output. +* A function for grouping an iterator's output. + +Creating new iterators +---------------------- + +``itertools.count(n)`` returns an infinite stream of integers, increasing by 1 +each time. You can optionally supply the starting number, which defaults to 0:: + + itertools.count() => + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ... + itertools.count(10) => + 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, ... + +``itertools.cycle(iter)`` saves a copy of the contents of a provided iterable +and returns a new iterator that returns its elements from first to last. The +new iterator will repeat these elements infinitely. + +:: + + itertools.cycle([1,2,3,4,5]) => + 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, ... + +``itertools.repeat(elem, [n])`` returns the provided element ``n`` times, or +returns the element endlessly if ``n`` is not provided. + +:: + + itertools.repeat('abc') => + abc, abc, abc, abc, abc, abc, abc, abc, abc, abc, ... + itertools.repeat('abc', 5) => + abc, abc, abc, abc, abc + +``itertools.chain(iterA, iterB, ...)`` takes an arbitrary number of iterables as +input, and returns all the elements of the first iterator, then all the elements +of the second, and so on, until all of the iterables have been exhausted. + +:: + + itertools.chain(['a', 'b', 'c'], (1, 2, 3)) => + a, b, c, 1, 2, 3 + +``itertools.izip(iterA, iterB, ...)`` takes one element from each iterable and +returns them in a tuple:: + + itertools.izip(['a', 'b', 'c'], (1, 2, 3)) => + ('a', 1), ('b', 2), ('c', 3) + +It's similiar to the built-in :func:`zip` function, but doesn't construct an +in-memory list and exhaust all the input iterators before returning; instead +tuples are constructed and returned only if they're requested. (The technical +term for this behaviour is `lazy evaluation +`__.) + +This iterator is intended to be used with iterables that are all of the same +length. If the iterables are of different lengths, the resulting stream will be +the same length as the shortest iterable. + +:: + + itertools.izip(['a', 'b'], (1, 2, 3)) => + ('a', 1), ('b', 2) + +You should avoid doing this, though, because an element may be taken from the +longer iterators and discarded. This means you can't go on to use the iterators +further because you risk skipping a discarded element. + +``itertools.islice(iter, [start], stop, [step])`` returns a stream that's a +slice of the iterator. With a single ``stop`` argument, it will return the +first ``stop`` elements. If you supply a starting index, you'll get +``stop-start`` elements, and if you supply a value for ``step``, elements will +be skipped accordingly. Unlike Python's string and list slicing, you can't use +negative values for ``start``, ``stop``, or ``step``. + +:: + + itertools.islice(range(10), 8) => + 0, 1, 2, 3, 4, 5, 6, 7 + itertools.islice(range(10), 2, 8) => + 2, 3, 4, 5, 6, 7 + itertools.islice(range(10), 2, 8, 2) => + 2, 4, 6 + +``itertools.tee(iter, [n])`` replicates an iterator; it returns ``n`` +independent iterators that will all return the contents of the source iterator. +If you don't supply a value for ``n``, the default is 2. Replicating iterators +requires saving some of the contents of the source iterator, so this can consume +significant memory if the iterator is large and one of the new iterators is +consumed more than the others. + +:: + + itertools.tee( itertools.count() ) => + iterA, iterB + + where iterA -> + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ... + + and iterB -> + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, ... + + +Calling functions on elements +----------------------------- + +Two functions are used for calling other functions on the contents of an +iterable. + +``itertools.imap(f, iterA, iterB, ...)`` returns a stream containing +``f(iterA[0], iterB[0]), f(iterA[1], iterB[1]), f(iterA[2], iterB[2]), ...``:: + + itertools.imap(operator.add, [5, 6, 5], [1, 2, 3]) => + 6, 8, 8 + +The ``operator`` module contains a set of functions corresponding to Python's +operators. Some examples are ``operator.add(a, b)`` (adds two values), +``operator.ne(a, b)`` (same as ``a!=b``), and ``operator.attrgetter('id')`` +(returns a callable that fetches the ``"id"`` attribute). + +``itertools.starmap(func, iter)`` assumes that the iterable will return a stream +of tuples, and calls ``f()`` using these tuples as the arguments:: + + itertools.starmap(os.path.join, + [('/usr', 'bin', 'java'), ('/bin', 'python'), + ('/usr', 'bin', 'perl'),('/usr', 'bin', 'ruby')]) + => + /usr/bin/java, /bin/python, /usr/bin/perl, /usr/bin/ruby + + +Selecting elements +------------------ + +Another group of functions chooses a subset of an iterator's elements based on a +predicate. + +``itertools.ifilter(predicate, iter)`` returns all the elements for which the +predicate returns true:: + + def is_even(x): + return (x % 2) == 0 + + itertools.ifilter(is_even, itertools.count()) => + 0, 2, 4, 6, 8, 10, 12, 14, ... + +``itertools.ifilterfalse(predicate, iter)`` is the opposite, returning all +elements for which the predicate returns false:: + + itertools.ifilterfalse(is_even, itertools.count()) => + 1, 3, 5, 7, 9, 11, 13, 15, ... + +``itertools.takewhile(predicate, iter)`` returns elements for as long as the +predicate returns true. Once the predicate returns false, the iterator will +signal the end of its results. + +:: + + def less_than_10(x): + return (x < 10) + + itertools.takewhile(less_than_10, itertools.count()) => + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 + + itertools.takewhile(is_even, itertools.count()) => + 0 + +``itertools.dropwhile(predicate, iter)`` discards elements while the predicate +returns true, and then returns the rest of the iterable's results. + +:: + + itertools.dropwhile(less_than_10, itertools.count()) => + 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, ... + + itertools.dropwhile(is_even, itertools.count()) => + 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ... + + +Grouping elements +----------------- + +The last function I'll discuss, ``itertools.groupby(iter, key_func=None)``, is +the most complicated. ``key_func(elem)`` is a function that can compute a key +value for each element returned by the iterable. If you don't supply a key +function, the key is simply each element itself. + +``groupby()`` collects all the consecutive elements from the underlying iterable +that have the same key value, and returns a stream of 2-tuples containing a key +value and an iterator for the elements with that key. + +:: + + city_list = [('Decatur', 'AL'), ('Huntsville', 'AL'), ('Selma', 'AL'), + ('Anchorage', 'AK'), ('Nome', 'AK'), + ('Flagstaff', 'AZ'), ('Phoenix', 'AZ'), ('Tucson', 'AZ'), + ... + ] + + def get_state ((city, state)): + return state + + itertools.groupby(city_list, get_state) => + ('AL', iterator-1), + ('AK', iterator-2), + ('AZ', iterator-3), ... + + where + iterator-1 => + ('Decatur', 'AL'), ('Huntsville', 'AL'), ('Selma', 'AL') + iterator-2 => + ('Anchorage', 'AK'), ('Nome', 'AK') + iterator-3 => + ('Flagstaff', 'AZ'), ('Phoenix', 'AZ'), ('Tucson', 'AZ') + +``groupby()`` assumes that the underlying iterable's contents will already be +sorted based on the key. Note that the returned iterators also use the +underlying iterable, so you have to consume the results of iterator-1 before +requesting iterator-2 and its corresponding key. + + +The functools module +==================== + +The :mod:`functools` module in Python 2.5 contains some higher-order functions. +A **higher-order function** takes one or more functions as input and returns a +new function. The most useful tool in this module is the +:func:`functools.partial` function. + +For programs written in a functional style, you'll sometimes want to construct +variants of existing functions that have some of the parameters filled in. +Consider a Python function ``f(a, b, c)``; you may wish to create a new function +``g(b, c)`` that's equivalent to ``f(1, b, c)``; you're filling in a value for +one of ``f()``'s parameters. This is called "partial function application". + +The constructor for ``partial`` takes the arguments ``(function, arg1, arg2, +... kwarg1=value1, kwarg2=value2)``. The resulting object is callable, so you +can just call it to invoke ``function`` with the filled-in arguments. + +Here's a small but realistic example:: + + import functools + + def log (message, subsystem): + "Write the contents of 'message' to the specified subsystem." + print '%s: %s' % (subsystem, message) + ... + + server_log = functools.partial(log, subsystem='server') + server_log('Unable to open socket') + + +The operator module +------------------- + +The :mod:`operator` module was mentioned earlier. It contains a set of +functions corresponding to Python's operators. These functions are often useful +in functional-style code because they save you from writing trivial functions +that perform a single operation. + +Some of the functions in this module are: + +* Math operations: ``add()``, ``sub()``, ``mul()``, ``div()``, ``floordiv()``, + ``abs()``, ... +* Logical operations: ``not_()``, ``truth()``. +* Bitwise operations: ``and_()``, ``or_()``, ``invert()``. +* Comparisons: ``eq()``, ``ne()``, ``lt()``, ``le()``, ``gt()``, and ``ge()``. +* Object identity: ``is_()``, ``is_not()``. + +Consult the operator module's documentation for a complete list. + + + +The functional module +--------------------- + +Collin Winter's `functional module `__ +provides a number of more advanced tools for functional programming. It also +reimplements several Python built-ins, trying to make them more intuitive to +those used to functional programming in other languages. + +This section contains an introduction to some of the most important functions in +``functional``; full documentation can be found at `the project's website +`__. + +``compose(outer, inner, unpack=False)`` + +The ``compose()`` function implements function composition. In other words, it +returns a wrapper around the ``outer`` and ``inner`` callables, such that the +return value from ``inner`` is fed directly to ``outer``. That is, + +:: + + >>> def add(a, b): + ... return a + b + ... + >>> def double(a): + ... return 2 * a + ... + >>> compose(double, add)(5, 6) + 22 + +is equivalent to + +:: + + >>> double(add(5, 6)) + 22 + +The ``unpack`` keyword is provided to work around the fact that Python functions +are not always `fully curried `__. By +default, it is expected that the ``inner`` function will return a single object +and that the ``outer`` function will take a single argument. Setting the +``unpack`` argument causes ``compose`` to expect a tuple from ``inner`` which +will be expanded before being passed to ``outer``. Put simply, + +:: + + compose(f, g)(5, 6) + +is equivalent to:: + + f(g(5, 6)) + +while + +:: + + compose(f, g, unpack=True)(5, 6) + +is equivalent to:: + + f(*g(5, 6)) + +Even though ``compose()`` only accepts two functions, it's trivial to build up a +version that will compose any number of functions. We'll use ``reduce()``, +``compose()`` and ``partial()`` (the last of which is provided by both +``functional`` and ``functools``). + +:: + + from functional import compose, partial + + multi_compose = partial(reduce, compose) + + +We can also use ``map()``, ``compose()`` and ``partial()`` to craft a version of +``"".join(...)`` that converts its arguments to string:: + + from functional import compose, partial + + join = compose("".join, partial(map, str)) + + +``flip(func)`` + +``flip()`` wraps the callable in ``func`` and causes it to receive its +non-keyword arguments in reverse order. + +:: + + >>> def triple(a, b, c): + ... return (a, b, c) + ... + >>> triple(5, 6, 7) + (5, 6, 7) + >>> + >>> flipped_triple = flip(triple) + >>> flipped_triple(5, 6, 7) + (7, 6, 5) + +``foldl(func, start, iterable)`` + +``foldl()`` takes a binary function, a starting value (usually some kind of +'zero'), and an iterable. The function is applied to the starting value and the +first element of the list, then the result of that and the second element of the +list, then the result of that and the third element of the list, and so on. + +This means that a call such as:: + + foldl(f, 0, [1, 2, 3]) + +is equivalent to:: + + f(f(f(0, 1), 2), 3) + + +``foldl()`` is roughly equivalent to the following recursive function:: + + def foldl(func, start, seq): + if len(seq) == 0: + return start + + return foldl(func, func(start, seq[0]), seq[1:]) + +Speaking of equivalence, the above ``foldl`` call can be expressed in terms of +the built-in ``reduce`` like so:: + + reduce(f, [1, 2, 3], 0) + + +We can use ``foldl()``, ``operator.concat()`` and ``partial()`` to write a +cleaner, more aesthetically-pleasing version of Python's ``"".join(...)`` +idiom:: + + from functional import foldl, partial + from operator import concat + + join = partial(foldl, concat, "") + + +Revision History and Acknowledgements +===================================== + +The author would like to thank the following people for offering suggestions, +corrections and assistance with various drafts of this article: Ian Bicking, +Nick Coghlan, Nick Efford, Raymond Hettinger, Jim Jewett, Mike Krell, Leandro +Lameiro, Jussi Salmela, Collin Winter, Blake Winton. + +Version 0.1: posted June 30 2006. + +Version 0.11: posted July 1 2006. Typo fixes. + +Version 0.2: posted July 10 2006. Merged genexp and listcomp sections into one. +Typo fixes. + +Version 0.21: Added more references suggested on the tutor mailing list. + +Version 0.30: Adds a section on the ``functional`` module written by Collin +Winter; adds short section on the operator module; a few other edits. + + +References +========== + +General +------- + +**Structure and Interpretation of Computer Programs**, by Harold Abelson and +Gerald Jay Sussman with Julie Sussman. Full text at +http://mitpress.mit.edu/sicp/. In this classic textbook of computer science, +chapters 2 and 3 discuss the use of sequences and streams to organize the data +flow inside a program. The book uses Scheme for its examples, but many of the +design approaches described in these chapters are applicable to functional-style +Python code. + +http://www.defmacro.org/ramblings/fp.html: A general introduction to functional +programming that uses Java examples and has a lengthy historical introduction. + +http://en.wikipedia.org/wiki/Functional_programming: General Wikipedia entry +describing functional programming. + +http://en.wikipedia.org/wiki/Coroutine: Entry for coroutines. + +http://en.wikipedia.org/wiki/Currying: Entry for the concept of currying. + +Python-specific +--------------- + +http://gnosis.cx/TPiP/: The first chapter of David Mertz's book +:title-reference:`Text Processing in Python` discusses functional programming +for text processing, in the section titled "Utilizing Higher-Order Functions in +Text Processing". + +Mertz also wrote a 3-part series of articles on functional programming +for IBM's DeveloperWorks site; see +`part 1 `__, +`part 2 `__, and +`part 3 `__, + + +Python documentation +-------------------- + +Documentation for the :mod:`itertools` module. + +Documentation for the :mod:`operator` module. + +:pep:`289`: "Generator Expressions" + +:pep:`342`: "Coroutines via Enhanced Generators" describes the new generator +features in Python 2.5. + +.. comment + + Topics to place + ----------------------------- + + XXX os.walk() + + XXX Need a large example. + + But will an example add much? I'll post a first draft and see + what the comments say. + +.. comment + + Original outline: + Introduction + Idea of FP + Programs built out of functions + Functions are strictly input-output, no internal state + Opposed to OO programming, where objects have state + + Why FP? + Formal provability + Assignment is difficult to reason about + Not very relevant to Python + Modularity + Small functions that do one thing + Debuggability: + Easy to test due to lack of state + Easy to verify output from intermediate steps + Composability + You assemble a toolbox of functions that can be mixed + + Tackling a problem + Need a significant example + + Iterators + Generators + The itertools module + List comprehensions + Small functions and the lambda statement + Built-in functions + map + filter + reduce + +.. comment + + Handy little function for printing part of an iterator -- used + while writing this document. + + import itertools + def print_iter(it): + slice = itertools.islice(it, 10) + for elem in slice[:-1]: + sys.stdout.write(str(elem)) + sys.stdout.write(', ') + print elem[-1] + + diff --git a/Doc/howto/index.rst b/Doc/howto/index.rst new file mode 100644 index 0000000..e668856 --- /dev/null +++ b/Doc/howto/index.rst @@ -0,0 +1,25 @@ +*************** + Python HOWTOs +*************** + +Python HOWTOs are documents that cover a single, specific topic, +and attempt to cover it fairly completely. Modelled on the Linux +Documentation Project's HOWTO collection, this collection is an +effort to foster documentation that's more detailed than the +Python Library Reference. + +Currently, the HOWTOs are: + +.. toctree:: + :maxdepth: 1 + + advocacy.rst + pythonmac.rst + curses.rst + doanddont.rst + functional.rst + regex.rst + sockets.rst + unicode.rst + urllib2.rst + diff --git a/Doc/howto/pythonmac.rst b/Doc/howto/pythonmac.rst new file mode 100644 index 0000000..7811f37 --- /dev/null +++ b/Doc/howto/pythonmac.rst @@ -0,0 +1,202 @@ + +.. _using-on-mac: + +*************************** +Using Python on a Macintosh +*************************** + +:Author: Bob Savage + + +Python on a Macintosh running Mac OS X is in principle very similar to Python on +any other Unix platform, but there are a number of additional features such as +the IDE and the Package Manager that are worth pointing out. + +The Mac-specific modules are documented in :ref:`mac-specific-services`. + +Python on Mac OS 9 or earlier can be quite different from Python on Unix or +Windows, but is beyond the scope of this manual, as that platform is no longer +supported, starting with Python 2.4. See http://www.cwi.nl/~jack/macpython for +installers for the latest 2.3 release for Mac OS 9 and related documentation. + + +.. _getting-osx: + +Getting and Installing MacPython +================================ + +Mac OS X 10.4 comes with Python 2.3 pre-installed by Apple. However, you are +encouraged to install the most recent version of Python from the Python website +(http://www.python.org). A "universal binary" build of Python 2.5, which runs +natively on the Mac's new Intel and legacy PPC CPU's, is available there. + +What you get after installing is a number of things: + +* A :file:`MacPython 2.5` folder in your :file:`Applications` folder. In here + you find IDLE, the development environment that is a standard part of official + Python distributions; PythonLauncher, which handles double-clicking Python + scripts from the Finder; and the "Build Applet" tool, which allows you to + package Python scripts as standalone applications on your system. + +* A framework :file:`/Library/Frameworks/Python.framework`, which includes the + Python executable and libraries. The installer adds this location to your shell + path. To uninstall MacPython, you can simply remove these three things. A + symlink to the Python executable is placed in /usr/local/bin/. + +The Apple-provided build of Python is installed in +:file:`/System/Library/Frameworks/Python.framework` and :file:`/usr/bin/python`, +respectively. You should never modify or delete these, as they are +Apple-controlled and are used by Apple- or third-party software. + +IDLE includes a help menu that allows you to access Python documentation. If you +are completely new to Python you should start reading the tutorial introduction +in that document. + +If you are familiar with Python on other Unix platforms you should read the +section on running Python scripts from the Unix shell. + + +How to run a Python script +-------------------------- + +Your best way to get started with Python on Mac OS X is through the IDLE +integrated development environment, see section :ref:`ide` and use the Help menu +when the IDE is running. + +If you want to run Python scripts from the Terminal window command line or from +the Finder you first need an editor to create your script. Mac OS X comes with a +number of standard Unix command line editors, :program:`vim` and +:program:`emacs` among them. If you want a more Mac-like editor, +:program:`BBEdit` or :program:`TextWrangler` from Bare Bones Software (see +http://www.barebones.com/products/bbedit/index.shtml) are good choices, as is +:program:`TextMate` (see http://macromates.com/). Other editors include +:program:`Gvim` (http://macvim.org) and :program:`Aquamacs` +(http://aquamacs.org). + +To run your script from the Terminal window you must make sure that +:file:`/usr/local/bin` is in your shell search path. + +To run your script from the Finder you have two options: + +* Drag it to :program:`PythonLauncher` + +* Select :program:`PythonLauncher` as the default application to open your + script (or any .py script) through the finder Info window and double-click it. + :program:`PythonLauncher` has various preferences to control how your script is + launched. Option-dragging allows you to change these for one invocation, or use + its Preferences menu to change things globally. + + +.. _osx-gui-scripts: + +Running scripts with a GUI +-------------------------- + +With older versions of Python, there is one Mac OS X quirk that you need to be +aware of: programs that talk to the Aqua window manager (in other words, +anything that has a GUI) need to be run in a special way. Use :program:`pythonw` +instead of :program:`python` to start such scripts. + +With Python 2.5, you can use either :program:`python` or :program:`pythonw`. + + +Configuration +------------- + +Python on OS X honors all standard Unix environment variables such as +:envvar:`PYTHONPATH`, but setting these variables for programs started from the +Finder is non-standard as the Finder does not read your :file:`.profile` or +:file:`.cshrc` at startup. You need to create a file :file:`~ +/.MacOSX/environment.plist`. See Apple's Technical Document QA1067 for details. + +For more information on installation Python packages in MacPython, see section +:ref:`mac-package-manager`. + + +.. _ide: + +The IDE +======= + +MacPython ships with the standard IDLE development environment. A good +introduction to using IDLE can be found at http://hkn.eecs.berkeley.edu/ +dyoo/python/idle_intro/index.html. + + +.. _mac-package-manager: + +Installing Additional Python Packages +===================================== + +There are several methods to install additional Python packages: + +* http://pythonmac.org/packages/ contains selected compiled packages for Python + 2.5, 2.4, and 2.3. + +* Packages can be installed via the standard Python distutils mode (``python + setup.py install``). + +* Many packages can also be installed via the :program:`setuptools` extension. + + +GUI Programming on the Mac +========================== + +There are several options for building GUI applications on the Mac with Python. + +*PyObjC* is a Python binding to Apple's Objective-C/Cocoa framework, which is +the foundation of most modern Mac development. Information on PyObjC is +available from http://pyobjc.sourceforge.net. + +The standard Python GUI toolkit is :mod:`Tkinter`, based on the cross-platform +Tk toolkit (http://www.tcl.tk). An Aqua-native version of Tk is bundled with OS +X by Apple, and the latest version can be downloaded and installed from +http://www.activestate.com; it can also be built from source. + +*wxPython* is another popular cross-platform GUI toolkit that runs natively on +Mac OS X. Packages and documentation are available from http://www.wxpython.org. + +*PyQt* is another popular cross-platform GUI toolkit that runs natively on Mac +OS X. More information can be found at +http://www.riverbankcomputing.co.uk/pyqt/. + + +Distributing Python Applications on the Mac +=========================================== + +The "Build Applet" tool that is placed in the MacPython 2.5 folder is fine for +packaging small Python scripts on your own machine to run as a standard Mac +application. This tool, however, is not robust enough to distribute Python +applications to other users. + +The standard tool for deploying standalone Python applications on the Mac is +:program:`py2app`. More information on installing and using py2app can be found +at http://undefined.org/python/#py2app. + + +Application Scripting +===================== + +Python can also be used to script other Mac applications via Apple's Open +Scripting Architecture (OSA); see http://appscript.sourceforge.net. Appscript is +a high-level, user-friendly Apple event bridge that allows you to control +scriptable Mac OS X applications using ordinary Python scripts. Appscript makes +Python a serious alternative to Apple's own *AppleScript* language for +automating your Mac. A related package, *PyOSA*, is an OSA language component +for the Python scripting language, allowing Python code to be executed by any +OSA-enabled application (Script Editor, Mail, iTunes, etc.). PyOSA makes Python +a full peer to AppleScript. + + +Other Resources +=============== + +The MacPython mailing list is an excellent support resource for Python users and +developers on the Mac: + +http://www.python.org/community/sigs/current/pythonmac-sig/ + +Another useful resource is the MacPython wiki: + +http://wiki.python.org/moin/MacPython + diff --git a/Doc/howto/regex.rst b/Doc/howto/regex.rst new file mode 100644 index 0000000..b200764 --- /dev/null +++ b/Doc/howto/regex.rst @@ -0,0 +1,1377 @@ +**************************** + Regular Expression HOWTO +**************************** + +:Author: A.M. Kuchling +:Release: 0.05 + +.. % TODO: +.. % Document lookbehind assertions +.. % Better way of displaying a RE, a string, and what it matches +.. % Mention optional argument to match.groups() +.. % Unicode (at least a reference) + + +.. topic:: Abstract + + This document is an introductory tutorial to using regular expressions in Python + with the :mod:`re` module. It provides a gentler introduction than the + corresponding section in the Library Reference. + + +Introduction +============ + +The :mod:`re` module was added in Python 1.5, and provides Perl-style regular +expression patterns. Earlier versions of Python came with the :mod:`regex` +module, which provided Emacs-style patterns. The :mod:`regex` module was +removed completely in Python 2.5. + +Regular expressions (called REs, or regexes, or regex patterns) are essentially +a tiny, highly specialized programming language embedded inside Python and made +available through the :mod:`re` module. Using this little language, you specify +the rules for the set of possible strings that you want to match; this set might +contain English sentences, or e-mail addresses, or TeX commands, or anything you +like. You can then ask questions such as "Does this string match the pattern?", +or "Is there a match for the pattern anywhere in this string?". You can also +use REs to modify a string or to split it apart in various ways. + +Regular expression patterns are compiled into a series of bytecodes which are +then executed by a matching engine written in C. For advanced use, it may be +necessary to pay careful attention to how the engine will execute a given RE, +and write the RE in a certain way in order to produce bytecode that runs faster. +Optimization isn't covered in this document, because it requires that you have a +good understanding of the matching engine's internals. + +The regular expression language is relatively small and restricted, so not all +possible string processing tasks can be done using regular expressions. There +are also tasks that *can* be done with regular expressions, but the expressions +turn out to be very complicated. In these cases, you may be better off writing +Python code to do the processing; while Python code will be slower than an +elaborate regular expression, it will also probably be more understandable. + + +Simple Patterns +=============== + +We'll start by learning about the simplest possible regular expressions. Since +regular expressions are used to operate on strings, we'll begin with the most +common task: matching characters. + +For a detailed explanation of the computer science underlying regular +expressions (deterministic and non-deterministic finite automata), you can refer +to almost any textbook on writing compilers. + + +Matching Characters +------------------- + +Most letters and characters will simply match themselves. For example, the +regular expression ``test`` will match the string ``test`` exactly. (You can +enable a case-insensitive mode that would let this RE match ``Test`` or ``TEST`` +as well; more about this later.) + +There are exceptions to this rule; some characters are special +:dfn:`metacharacters`, and don't match themselves. Instead, they signal that +some out-of-the-ordinary thing should be matched, or they affect other portions +of the RE by repeating them or changing their meaning. Much of this document is +devoted to discussing various metacharacters and what they do. + +Here's a complete list of the metacharacters; their meanings will be discussed +in the rest of this HOWTO. :: + + . ^ $ * + ? { [ ] \ | ( ) + +The first metacharacters we'll look at are ``[`` and ``]``. They're used for +specifying a character class, which is a set of characters that you wish to +match. Characters can be listed individually, or a range of characters can be +indicated by giving two characters and separating them by a ``'-'``. For +example, ``[abc]`` will match any of the characters ``a``, ``b``, or ``c``; this +is the same as ``[a-c]``, which uses a range to express the same set of +characters. If you wanted to match only lowercase letters, your RE would be +``[a-z]``. + +.. % $ + +Metacharacters are not active inside classes. For example, ``[akm$]`` will +match any of the characters ``'a'``, ``'k'``, ``'m'``, or ``'$'``; ``'$'`` is +usually a metacharacter, but inside a character class it's stripped of its +special nature. + +You can match the characters not listed within the class by :dfn:`complementing` +the set. This is indicated by including a ``'^'`` as the first character of the +class; ``'^'`` outside a character class will simply match the ``'^'`` +character. For example, ``[^5]`` will match any character except ``'5'``. + +Perhaps the most important metacharacter is the backslash, ``\``. As in Python +string literals, the backslash can be followed by various characters to signal +various special sequences. It's also used to escape all the metacharacters so +you can still match them in patterns; for example, if you need to match a ``[`` +or ``\``, you can precede them with a backslash to remove their special +meaning: ``\[`` or ``\\``. + +Some of the special sequences beginning with ``'\'`` represent predefined sets +of characters that are often useful, such as the set of digits, the set of +letters, or the set of anything that isn't whitespace. The following predefined +special sequences are available: + +``\d`` + Matches any decimal digit; this is equivalent to the class ``[0-9]``. + +``\D`` + Matches any non-digit character; this is equivalent to the class ``[^0-9]``. + +``\s`` + Matches any whitespace character; this is equivalent to the class ``[ + \t\n\r\f\v]``. + +``\S`` + Matches any non-whitespace character; this is equivalent to the class ``[^ + \t\n\r\f\v]``. + +``\w`` + Matches any alphanumeric character; this is equivalent to the class + ``[a-zA-Z0-9_]``. + +``\W`` + Matches any non-alphanumeric character; this is equivalent to the class + ``[^a-zA-Z0-9_]``. + +These sequences can be included inside a character class. For example, +``[\s,.]`` is a character class that will match any whitespace character, or +``','`` or ``'.'``. + +The final metacharacter in this section is ``.``. It matches anything except a +newline character, and there's an alternate mode (``re.DOTALL``) where it will +match even a newline. ``'.'`` is often used where you want to match "any +character". + + +Repeating Things +---------------- + +Being able to match varying sets of characters is the first thing regular +expressions can do that isn't already possible with the methods available on +strings. However, if that was the only additional capability of regexes, they +wouldn't be much of an advance. Another capability is that you can specify that +portions of the RE must be repeated a certain number of times. + +The first metacharacter for repeating things that we'll look at is ``*``. ``*`` +doesn't match the literal character ``*``; instead, it specifies that the +previous character can be matched zero or more times, instead of exactly once. + +For example, ``ca*t`` will match ``ct`` (0 ``a`` characters), ``cat`` (1 ``a``), +``caaat`` (3 ``a`` characters), and so forth. The RE engine has various +internal limitations stemming from the size of C's ``int`` type that will +prevent it from matching over 2 billion ``a`` characters; you probably don't +have enough memory to construct a string that large, so you shouldn't run into +that limit. + +Repetitions such as ``*`` are :dfn:`greedy`; when repeating a RE, the matching +engine will try to repeat it as many times as possible. If later portions of the +pattern don't match, the matching engine will then back up and try again with +few repetitions. + +A step-by-step example will make this more obvious. Let's consider the +expression ``a[bcd]*b``. This matches the letter ``'a'``, zero or more letters +from the class ``[bcd]``, and finally ends with a ``'b'``. Now imagine matching +this RE against the string ``abcbd``. + ++------+-----------+---------------------------------+ +| Step | Matched | Explanation | ++======+===========+=================================+ +| 1 | ``a`` | The ``a`` in the RE matches. | ++------+-----------+---------------------------------+ +| 2 | ``abcbd`` | The engine matches ``[bcd]*``, | +| | | going as far as it can, which | +| | | is to the end of the string. | ++------+-----------+---------------------------------+ +| 3 | *Failure* | The engine tries to match | +| | | ``b``, but the current position | +| | | is at the end of the string, so | +| | | it fails. | ++------+-----------+---------------------------------+ +| 4 | ``abcb`` | Back up, so that ``[bcd]*`` | +| | | matches one less character. | ++------+-----------+---------------------------------+ +| 5 | *Failure* | Try ``b`` again, but the | +| | | current position is at the last | +| | | character, which is a ``'d'``. | ++------+-----------+---------------------------------+ +| 6 | ``abc`` | Back up again, so that | +| | | ``[bcd]*`` is only matching | +| | | ``bc``. | ++------+-----------+---------------------------------+ +| 6 | ``abcb`` | Try ``b`` again. This time | +| | | but the character at the | +| | | current position is ``'b'``, so | +| | | it succeeds. | ++------+-----------+---------------------------------+ + +The end of the RE has now been reached, and it has matched ``abcb``. This +demonstrates how the matching engine goes as far as it can at first, and if no +match is found it will then progressively back up and retry the rest of the RE +again and again. It will back up until it has tried zero matches for +``[bcd]*``, and if that subsequently fails, the engine will conclude that the +string doesn't match the RE at all. + +Another repeating metacharacter is ``+``, which matches one or more times. Pay +careful attention to the difference between ``*`` and ``+``; ``*`` matches +*zero* or more times, so whatever's being repeated may not be present at all, +while ``+`` requires at least *one* occurrence. To use a similar example, +``ca+t`` will match ``cat`` (1 ``a``), ``caaat`` (3 ``a``'s), but won't match +``ct``. + +There are two more repeating qualifiers. The question mark character, ``?``, +matches either once or zero times; you can think of it as marking something as +being optional. For example, ``home-?brew`` matches either ``homebrew`` or +``home-brew``. + +The most complicated repeated qualifier is ``{m,n}``, where *m* and *n* are +decimal integers. This qualifier means there must be at least *m* repetitions, +and at most *n*. For example, ``a/{1,3}b`` will match ``a/b``, ``a//b``, and +``a///b``. It won't match ``ab``, which has no slashes, or ``a////b``, which +has four. + +You can omit either *m* or *n*; in that case, a reasonable value is assumed for +the missing value. Omitting *m* is interpreted as a lower limit of 0, while +omitting *n* results in an upper bound of infinity --- actually, the upper bound +is the 2-billion limit mentioned earlier, but that might as well be infinity. + +Readers of a reductionist bent may notice that the three other qualifiers can +all be expressed using this notation. ``{0,}`` is the same as ``*``, ``{1,}`` +is equivalent to ``+``, and ``{0,1}`` is the same as ``?``. It's better to use +``*``, ``+``, or ``?`` when you can, simply because they're shorter and easier +to read. + + +Using Regular Expressions +========================= + +Now that we've looked at some simple regular expressions, how do we actually use +them in Python? The :mod:`re` module provides an interface to the regular +expression engine, allowing you to compile REs into objects and then perform +matches with them. + + +Compiling Regular Expressions +----------------------------- + +Regular expressions are compiled into :class:`RegexObject` instances, which have +methods for various operations such as searching for pattern matches or +performing string substitutions. :: + + >>> import re + >>> p = re.compile('ab*') + >>> print p + + +:func:`re.compile` also accepts an optional *flags* argument, used to enable +various special features and syntax variations. We'll go over the available +settings later, but for now a single example will do:: + + >>> p = re.compile('ab*', re.IGNORECASE) + +The RE is passed to :func:`re.compile` as a string. REs are handled as strings +because regular expressions aren't part of the core Python language, and no +special syntax was created for expressing them. (There are applications that +don't need REs at all, so there's no need to bloat the language specification by +including them.) Instead, the :mod:`re` module is simply a C extension module +included with Python, just like the :mod:`socket` or :mod:`zlib` modules. + +Putting REs in strings keeps the Python language simpler, but has one +disadvantage which is the topic of the next section. + + +The Backslash Plague +-------------------- + +As stated earlier, regular expressions use the backslash character (``'\'``) to +indicate special forms or to allow special characters to be used without +invoking their special meaning. This conflicts with Python's usage of the same +character for the same purpose in string literals. + +Let's say you want to write a RE that matches the string ``\section``, which +might be found in a LaTeX file. To figure out what to write in the program +code, start with the desired string to be matched. Next, you must escape any +backslashes and other metacharacters by preceding them with a backslash, +resulting in the string ``\\section``. The resulting string that must be passed +to :func:`re.compile` must be ``\\section``. However, to express this as a +Python string literal, both backslashes must be escaped *again*. + ++-------------------+------------------------------------------+ +| Characters | Stage | ++===================+==========================================+ +| ``\section`` | Text string to be matched | ++-------------------+------------------------------------------+ +| ``\\section`` | Escaped backslash for :func:`re.compile` | ++-------------------+------------------------------------------+ +| ``"\\\\section"`` | Escaped backslashes for a string literal | ++-------------------+------------------------------------------+ + +In short, to match a literal backslash, one has to write ``'\\\\'`` as the RE +string, because the regular expression must be ``\\``, and each backslash must +be expressed as ``\\`` inside a regular Python string literal. In REs that +feature backslashes repeatedly, this leads to lots of repeated backslashes and +makes the resulting strings difficult to understand. + +The solution is to use Python's raw string notation for regular expressions; +backslashes are not handled in any special way in a string literal prefixed with +``'r'``, so ``r"\n"`` is a two-character string containing ``'\'`` and ``'n'``, +while ``"\n"`` is a one-character string containing a newline. Regular +expressions will often be written in Python code using this raw string notation. + ++-------------------+------------------+ +| Regular String | Raw string | ++===================+==================+ +| ``"ab*"`` | ``r"ab*"`` | ++-------------------+------------------+ +| ``"\\\\section"`` | ``r"\\section"`` | ++-------------------+------------------+ +| ``"\\w+\\s+\\1"`` | ``r"\w+\s+\1"`` | ++-------------------+------------------+ + + +Performing Matches +------------------ + +Once you have an object representing a compiled regular expression, what do you +do with it? :class:`RegexObject` instances have several methods and attributes. +Only the most significant ones will be covered here; consult `the Library +Reference `_ for a complete +listing. + ++------------------+-----------------------------------------------+ +| Method/Attribute | Purpose | ++==================+===============================================+ +| ``match()`` | Determine if the RE matches at the beginning | +| | of the string. | ++------------------+-----------------------------------------------+ +| ``search()`` | Scan through a string, looking for any | +| | location where this RE matches. | ++------------------+-----------------------------------------------+ +| ``findall()`` | Find all substrings where the RE matches, and | +| | returns them as a list. | ++------------------+-----------------------------------------------+ +| ``finditer()`` | Find all substrings where the RE matches, and | +| | returns them as an iterator. | ++------------------+-----------------------------------------------+ + +:meth:`match` and :meth:`search` return ``None`` if no match can be found. If +they're successful, a ``MatchObject`` instance is returned, containing +information about the match: where it starts and ends, the substring it matched, +and more. + +You can learn about this by interactively experimenting with the :mod:`re` +module. If you have Tkinter available, you may also want to look at +:file:`Tools/scripts/redemo.py`, a demonstration program included with the +Python distribution. It allows you to enter REs and strings, and displays +whether the RE matches or fails. :file:`redemo.py` can be quite useful when +trying to debug a complicated RE. Phil Schwartz's `Kodos +`_ is also an interactive tool for +developing and testing RE patterns. + +This HOWTO uses the standard Python interpreter for its examples. First, run the +Python interpreter, import the :mod:`re` module, and compile a RE:: + + Python 2.2.2 (#1, Feb 10 2003, 12:57:01) + >>> import re + >>> p = re.compile('[a-z]+') + >>> p + <_sre.SRE_Pattern object at 80c3c28> + +Now, you can try matching various strings against the RE ``[a-z]+``. An empty +string shouldn't match at all, since ``+`` means 'one or more repetitions'. +:meth:`match` should return ``None`` in this case, which will cause the +interpreter to print no output. You can explicitly print the result of +:meth:`match` to make this clear. :: + + >>> p.match("") + >>> print p.match("") + None + +Now, let's try it on a string that it should match, such as ``tempo``. In this +case, :meth:`match` will return a :class:`MatchObject`, so you should store the +result in a variable for later use. :: + + >>> m = p.match('tempo') + >>> print m + <_sre.SRE_Match object at 80c4f68> + +Now you can query the :class:`MatchObject` for information about the matching +string. :class:`MatchObject` instances also have several methods and +attributes; the most important ones are: + ++------------------+--------------------------------------------+ +| Method/Attribute | Purpose | ++==================+============================================+ +| ``group()`` | Return the string matched by the RE | ++------------------+--------------------------------------------+ +| ``start()`` | Return the starting position of the match | ++------------------+--------------------------------------------+ +| ``end()`` | Return the ending position of the match | ++------------------+--------------------------------------------+ +| ``span()`` | Return a tuple containing the (start, end) | +| | positions of the match | ++------------------+--------------------------------------------+ + +Trying these methods will soon clarify their meaning:: + + >>> m.group() + 'tempo' + >>> m.start(), m.end() + (0, 5) + >>> m.span() + (0, 5) + +:meth:`group` returns the substring that was matched by the RE. :meth:`start` +and :meth:`end` return the starting and ending index of the match. :meth:`span` +returns both start and end indexes in a single tuple. Since the :meth:`match` +method only checks if the RE matches at the start of a string, :meth:`start` +will always be zero. However, the :meth:`search` method of :class:`RegexObject` +instances scans through the string, so the match may not start at zero in that +case. :: + + >>> print p.match('::: message') + None + >>> m = p.search('::: message') ; print m + + >>> m.group() + 'message' + >>> m.span() + (4, 11) + +In actual programs, the most common style is to store the :class:`MatchObject` +in a variable, and then check if it was ``None``. This usually looks like:: + + p = re.compile( ... ) + m = p.match( 'string goes here' ) + if m: + print 'Match found: ', m.group() + else: + print 'No match' + +Two :class:`RegexObject` methods return all of the matches for a pattern. +:meth:`findall` returns a list of matching strings:: + + >>> p = re.compile('\d+') + >>> p.findall('12 drummers drumming, 11 pipers piping, 10 lords a-leaping') + ['12', '11', '10'] + +:meth:`findall` has to create the entire list before it can be returned as the +result. The :meth:`finditer` method returns a sequence of :class:`MatchObject` +instances as an iterator. [#]_ :: + + >>> iterator = p.finditer('12 drummers drumming, 11 ... 10 ...') + >>> iterator + + >>> for match in iterator: + ... print match.span() + ... + (0, 2) + (22, 24) + (29, 31) + + +Module-Level Functions +---------------------- + +You don't have to create a :class:`RegexObject` and call its methods; the +:mod:`re` module also provides top-level functions called :func:`match`, +:func:`search`, :func:`findall`, :func:`sub`, and so forth. These functions +take the same arguments as the corresponding :class:`RegexObject` method, with +the RE string added as the first argument, and still return either ``None`` or a +:class:`MatchObject` instance. :: + + >>> print re.match(r'From\s+', 'Fromage amk') + None + >>> re.match(r'From\s+', 'From amk Thu May 14 19:12:10 1998') + + +Under the hood, these functions simply produce a :class:`RegexObject` for you +and call the appropriate method on it. They also store the compiled object in a +cache, so future calls using the same RE are faster. + +Should you use these module-level functions, or should you get the +:class:`RegexObject` and call its methods yourself? That choice depends on how +frequently the RE will be used, and on your personal coding style. If the RE is +being used at only one point in the code, then the module functions are probably +more convenient. If a program contains a lot of regular expressions, or re-uses +the same ones in several locations, then it might be worthwhile to collect all +the definitions in one place, in a section of code that compiles all the REs +ahead of time. To take an example from the standard library, here's an extract +from :file:`xmllib.py`:: + + ref = re.compile( ... ) + entityref = re.compile( ... ) + charref = re.compile( ... ) + starttagopen = re.compile( ... ) + +I generally prefer to work with the compiled object, even for one-time uses, but +few people will be as much of a purist about this as I am. + + +Compilation Flags +----------------- + +Compilation flags let you modify some aspects of how regular expressions work. +Flags are available in the :mod:`re` module under two names, a long name such as +:const:`IGNORECASE` and a short, one-letter form such as :const:`I`. (If you're +familiar with Perl's pattern modifiers, the one-letter forms use the same +letters; the short form of :const:`re.VERBOSE` is :const:`re.X`, for example.) +Multiple flags can be specified by bitwise OR-ing them; ``re.I | re.M`` sets +both the :const:`I` and :const:`M` flags, for example. + +Here's a table of the available flags, followed by a more detailed explanation +of each one. + ++---------------------------------+--------------------------------------------+ +| Flag | Meaning | ++=================================+============================================+ +| :const:`DOTALL`, :const:`S` | Make ``.`` match any character, including | +| | newlines | ++---------------------------------+--------------------------------------------+ +| :const:`IGNORECASE`, :const:`I` | Do case-insensitive matches | ++---------------------------------+--------------------------------------------+ +| :const:`LOCALE`, :const:`L` | Do a locale-aware match | ++---------------------------------+--------------------------------------------+ +| :const:`MULTILINE`, :const:`M` | Multi-line matching, affecting ``^`` and | +| | ``$`` | ++---------------------------------+--------------------------------------------+ +| :const:`VERBOSE`, :const:`X` | Enable verbose REs, which can be organized | +| | more cleanly and understandably. | ++---------------------------------+--------------------------------------------+ + + +.. data:: I + IGNORECASE + :noindex: + + Perform case-insensitive matching; character class and literal strings will + match letters by ignoring case. For example, ``[A-Z]`` will match lowercase + letters, too, and ``Spam`` will match ``Spam``, ``spam``, or ``spAM``. This + lowercasing doesn't take the current locale into account; it will if you also + set the :const:`LOCALE` flag. + + +.. data:: L + LOCALE + :noindex: + + Make ``\w``, ``\W``, ``\b``, and ``\B``, dependent on the current locale. + + Locales are a feature of the C library intended to help in writing programs that + take account of language differences. For example, if you're processing French + text, you'd want to be able to write ``\w+`` to match words, but ``\w`` only + matches the character class ``[A-Za-z]``; it won't match ``'é'`` or ``'ç'``. If + your system is configured properly and a French locale is selected, certain C + functions will tell the program that ``'é'`` should also be considered a letter. + Setting the :const:`LOCALE` flag when compiling a regular expression will cause + the resulting compiled object to use these C functions for ``\w``; this is + slower, but also enables ``\w+`` to match French words as you'd expect. + + +.. data:: M + MULTILINE + :noindex: + + (``^`` and ``$`` haven't been explained yet; they'll be introduced in section + :ref:`more-metacharacters`.) + + Usually ``^`` matches only at the beginning of the string, and ``$`` matches + only at the end of the string and immediately before the newline (if any) at the + end of the string. When this flag is specified, ``^`` matches at the beginning + of the string and at the beginning of each line within the string, immediately + following each newline. Similarly, the ``$`` metacharacter matches either at + the end of the string and at the end of each line (immediately preceding each + newline). + + +.. data:: S + DOTALL + :noindex: + + Makes the ``'.'`` special character match any character at all, including a + newline; without this flag, ``'.'`` will match anything *except* a newline. + + +.. data:: X + VERBOSE + :noindex: + + This flag allows you to write regular expressions that are more readable by + granting you more flexibility in how you can format them. When this flag has + been specified, whitespace within the RE string is ignored, except when the + whitespace is in a character class or preceded by an unescaped backslash; this + lets you organize and indent the RE more clearly. This flag also lets you put + comments within a RE that will be ignored by the engine; comments are marked by + a ``'#'`` that's neither in a character class or preceded by an unescaped + backslash. + + For example, here's a RE that uses :const:`re.VERBOSE`; see how much easier it + is to read? :: + + charref = re.compile(r""" + &[#] # Start of a numeric entity reference + ( + 0[0-7]+ # Octal form + | [0-9]+ # Decimal form + | x[0-9a-fA-F]+ # Hexadecimal form + ) + ; # Trailing semicolon + """, re.VERBOSE) + + Without the verbose setting, the RE would look like this:: + + charref = re.compile("&#(0[0-7]+" + "|[0-9]+" + "|x[0-9a-fA-F]+);") + + In the above example, Python's automatic concatenation of string literals has + been used to break up the RE into smaller pieces, but it's still more difficult + to understand than the version using :const:`re.VERBOSE`. + + +More Pattern Power +================== + +So far we've only covered a part of the features of regular expressions. In +this section, we'll cover some new metacharacters, and how to use groups to +retrieve portions of the text that was matched. + + +.. _more-metacharacters: + +More Metacharacters +------------------- + +There are some metacharacters that we haven't covered yet. Most of them will be +covered in this section. + +Some of the remaining metacharacters to be discussed are :dfn:`zero-width +assertions`. They don't cause the engine to advance through the string; +instead, they consume no characters at all, and simply succeed or fail. For +example, ``\b`` is an assertion that the current position is located at a word +boundary; the position isn't changed by the ``\b`` at all. This means that +zero-width assertions should never be repeated, because if they match once at a +given location, they can obviously be matched an infinite number of times. + +``|`` + Alternation, or the "or" operator. If A and B are regular expressions, + ``A|B`` will match any string that matches either ``A`` or ``B``. ``|`` has very + low precedence in order to make it work reasonably when you're alternating + multi-character strings. ``Crow|Servo`` will match either ``Crow`` or ``Servo``, + not ``Cro``, a ``'w'`` or an ``'S'``, and ``ervo``. + + To match a literal ``'|'``, use ``\|``, or enclose it inside a character class, + as in ``[|]``. + +``^`` + Matches at the beginning of lines. Unless the :const:`MULTILINE` flag has been + set, this will only match at the beginning of the string. In :const:`MULTILINE` + mode, this also matches immediately after each newline within the string. + + For example, if you wish to match the word ``From`` only at the beginning of a + line, the RE to use is ``^From``. :: + + >>> print re.search('^From', 'From Here to Eternity') + + >>> print re.search('^From', 'Reciting From Memory') + None + + .. % To match a literal \character{\^}, use \regexp{\e\^} or enclose it + .. % inside a character class, as in \regexp{[{\e}\^]}. + +``$`` + Matches at the end of a line, which is defined as either the end of the string, + or any location followed by a newline character. :: + + >>> print re.search('}$', '{block}') + + >>> print re.search('}$', '{block} ') + None + >>> print re.search('}$', '{block}\n') + + + To match a literal ``'$'``, use ``\$`` or enclose it inside a character class, + as in ``[$]``. + + .. % $ + +``\A`` + Matches only at the start of the string. When not in :const:`MULTILINE` mode, + ``\A`` and ``^`` are effectively the same. In :const:`MULTILINE` mode, they're + different: ``\A`` still matches only at the beginning of the string, but ``^`` + may match at any location inside the string that follows a newline character. + +``\Z`` + Matches only at the end of the string. + +``\b`` + Word boundary. This is a zero-width assertion that matches only at the + beginning or end of a word. A word is defined as a sequence of alphanumeric + characters, so the end of a word is indicated by whitespace or a + non-alphanumeric character. + + The following example matches ``class`` only when it's a complete word; it won't + match when it's contained inside another word. :: + + >>> p = re.compile(r'\bclass\b') + >>> print p.search('no class at all') + + >>> print p.search('the declassified algorithm') + None + >>> print p.search('one subclass is') + None + + There are two subtleties you should remember when using this special sequence. + First, this is the worst collision between Python's string literals and regular + expression sequences. In Python's string literals, ``\b`` is the backspace + character, ASCII value 8. If you're not using raw strings, then Python will + convert the ``\b`` to a backspace, and your RE won't match as you expect it to. + The following example looks the same as our previous RE, but omits the ``'r'`` + in front of the RE string. :: + + >>> p = re.compile('\bclass\b') + >>> print p.search('no class at all') + None + >>> print p.search('\b' + 'class' + '\b') + + + Second, inside a character class, where there's no use for this assertion, + ``\b`` represents the backspace character, for compatibility with Python's + string literals. + +``\B`` + Another zero-width assertion, this is the opposite of ``\b``, only matching when + the current position is not at a word boundary. + + +Grouping +-------- + +Frequently you need to obtain more information than just whether the RE matched +or not. Regular expressions are often used to dissect strings by writing a RE +divided into several subgroups which match different components of interest. +For example, an RFC-822 header line is divided into a header name and a value, +separated by a ``':'``, like this:: + + From: author@example.com + User-Agent: Thunderbird 1.5.0.9 (X11/20061227) + MIME-Version: 1.0 + To: editor@example.com + +This can be handled by writing a regular expression which matches an entire +header line, and has one group which matches the header name, and another group +which matches the header's value. + +Groups are marked by the ``'('``, ``')'`` metacharacters. ``'('`` and ``')'`` +have much the same meaning as they do in mathematical expressions; they group +together the expressions contained inside them, and you can repeat the contents +of a group with a repeating qualifier, such as ``*``, ``+``, ``?``, or +``{m,n}``. For example, ``(ab)*`` will match zero or more repetitions of +``ab``. :: + + >>> p = re.compile('(ab)*') + >>> print p.match('ababababab').span() + (0, 10) + +Groups indicated with ``'('``, ``')'`` also capture the starting and ending +index of the text that they match; this can be retrieved by passing an argument +to :meth:`group`, :meth:`start`, :meth:`end`, and :meth:`span`. Groups are +numbered starting with 0. Group 0 is always present; it's the whole RE, so +:class:`MatchObject` methods all have group 0 as their default argument. Later +we'll see how to express groups that don't capture the span of text that they +match. :: + + >>> p = re.compile('(a)b') + >>> m = p.match('ab') + >>> m.group() + 'ab' + >>> m.group(0) + 'ab' + +Subgroups are numbered from left to right, from 1 upward. Groups can be nested; +to determine the number, just count the opening parenthesis characters, going +from left to right. :: + + >>> p = re.compile('(a(b)c)d') + >>> m = p.match('abcd') + >>> m.group(0) + 'abcd' + >>> m.group(1) + 'abc' + >>> m.group(2) + 'b' + +:meth:`group` can be passed multiple group numbers at a time, in which case it +will return a tuple containing the corresponding values for those groups. :: + + >>> m.group(2,1,2) + ('b', 'abc', 'b') + +The :meth:`groups` method returns a tuple containing the strings for all the +subgroups, from 1 up to however many there are. :: + + >>> m.groups() + ('abc', 'b') + +Backreferences in a pattern allow you to specify that the contents of an earlier +capturing group must also be found at the current location in the string. For +example, ``\1`` will succeed if the exact contents of group 1 can be found at +the current position, and fails otherwise. Remember that Python's string +literals also use a backslash followed by numbers to allow including arbitrary +characters in a string, so be sure to use a raw string when incorporating +backreferences in a RE. + +For example, the following RE detects doubled words in a string. :: + + >>> p = re.compile(r'(\b\w+)\s+\1') + >>> p.search('Paris in the the spring').group() + 'the the' + +Backreferences like this aren't often useful for just searching through a string +--- there are few text formats which repeat data in this way --- but you'll soon +find out that they're *very* useful when performing string substitutions. + + +Non-capturing and Named Groups +------------------------------ + +Elaborate REs may use many groups, both to capture substrings of interest, and +to group and structure the RE itself. In complex REs, it becomes difficult to +keep track of the group numbers. There are two features which help with this +problem. Both of them use a common syntax for regular expression extensions, so +we'll look at that first. + +Perl 5 added several additional features to standard regular expressions, and +the Python :mod:`re` module supports most of them. It would have been +difficult to choose new single-keystroke metacharacters or new special sequences +beginning with ``\`` to represent the new features without making Perl's regular +expressions confusingly different from standard REs. If you chose ``&`` as a +new metacharacter, for example, old expressions would be assuming that ``&`` was +a regular character and wouldn't have escaped it by writing ``\&`` or ``[&]``. + +The solution chosen by the Perl developers was to use ``(?...)`` as the +extension syntax. ``?`` immediately after a parenthesis was a syntax error +because the ``?`` would have nothing to repeat, so this didn't introduce any +compatibility problems. The characters immediately after the ``?`` indicate +what extension is being used, so ``(?=foo)`` is one thing (a positive lookahead +assertion) and ``(?:foo)`` is something else (a non-capturing group containing +the subexpression ``foo``). + +Python adds an extension syntax to Perl's extension syntax. If the first +character after the question mark is a ``P``, you know that it's an extension +that's specific to Python. Currently there are two such extensions: +``(?P...)`` defines a named group, and ``(?P=name)`` is a backreference to +a named group. If future versions of Perl 5 add similar features using a +different syntax, the :mod:`re` module will be changed to support the new +syntax, while preserving the Python-specific syntax for compatibility's sake. + +Now that we've looked at the general extension syntax, we can return to the +features that simplify working with groups in complex REs. Since groups are +numbered from left to right and a complex expression may use many groups, it can +become difficult to keep track of the correct numbering. Modifying such a +complex RE is annoying, too: insert a new group near the beginning and you +change the numbers of everything that follows it. + +Sometimes you'll want to use a group to collect a part of a regular expression, +but aren't interested in retrieving the group's contents. You can make this fact +explicit by using a non-capturing group: ``(?:...)``, where you can replace the +``...`` with any other regular expression. :: + + >>> m = re.match("([abc])+", "abc") + >>> m.groups() + ('c',) + >>> m = re.match("(?:[abc])+", "abc") + >>> m.groups() + () + +Except for the fact that you can't retrieve the contents of what the group +matched, a non-capturing group behaves exactly the same as a capturing group; +you can put anything inside it, repeat it with a repetition metacharacter such +as ``*``, and nest it within other groups (capturing or non-capturing). +``(?:...)`` is particularly useful when modifying an existing pattern, since you +can add new groups without changing how all the other groups are numbered. It +should be mentioned that there's no performance difference in searching between +capturing and non-capturing groups; neither form is any faster than the other. + +A more significant feature is named groups: instead of referring to them by +numbers, groups can be referenced by a name. + +The syntax for a named group is one of the Python-specific extensions: +``(?P...)``. *name* is, obviously, the name of the group. Named groups +also behave exactly like capturing groups, and additionally associate a name +with a group. The :class:`MatchObject` methods that deal with capturing groups +all accept either integers that refer to the group by number or strings that +contain the desired group's name. Named groups are still given numbers, so you +can retrieve information about a group in two ways:: + + >>> p = re.compile(r'(?P\b\w+\b)') + >>> m = p.search( '(((( Lots of punctuation )))' ) + >>> m.group('word') + 'Lots' + >>> m.group(1) + 'Lots' + +Named groups are handy because they let you use easily-remembered names, instead +of having to remember numbers. Here's an example RE from the :mod:`imaplib` +module:: + + InternalDate = re.compile(r'INTERNALDATE "' + r'(?P[ 123][0-9])-(?P[A-Z][a-z][a-z])-' + r'(?P[0-9][0-9][0-9][0-9])' + r' (?P[0-9][0-9]):(?P[0-9][0-9]):(?P[0-9][0-9])' + r' (?P[-+])(?P[0-9][0-9])(?P[0-9][0-9])' + r'"') + +It's obviously much easier to retrieve ``m.group('zonem')``, instead of having +to remember to retrieve group 9. + +The syntax for backreferences in an expression such as ``(...)\1`` refers to the +number of the group. There's naturally a variant that uses the group name +instead of the number. This is another Python extension: ``(?P=name)`` indicates +that the contents of the group called *name* should again be matched at the +current point. The regular expression for finding doubled words, +``(\b\w+)\s+\1`` can also be written as ``(?P\b\w+)\s+(?P=word)``:: + + >>> p = re.compile(r'(?P\b\w+)\s+(?P=word)') + >>> p.search('Paris in the the spring').group() + 'the the' + + +Lookahead Assertions +-------------------- + +Another zero-width assertion is the lookahead assertion. Lookahead assertions +are available in both positive and negative form, and look like this: + +``(?=...)`` + Positive lookahead assertion. This succeeds if the contained regular + expression, represented here by ``...``, successfully matches at the current + location, and fails otherwise. But, once the contained expression has been + tried, the matching engine doesn't advance at all; the rest of the pattern is + tried right where the assertion started. + +``(?!...)`` + Negative lookahead assertion. This is the opposite of the positive assertion; + it succeeds if the contained expression *doesn't* match at the current position + in the string. + +To make this concrete, let's look at a case where a lookahead is useful. +Consider a simple pattern to match a filename and split it apart into a base +name and an extension, separated by a ``.``. For example, in ``news.rc``, +``news`` is the base name, and ``rc`` is the filename's extension. + +The pattern to match this is quite simple: + +``.*[.].*$`` + +Notice that the ``.`` needs to be treated specially because it's a +metacharacter; I've put it inside a character class. Also notice the trailing +``$``; this is added to ensure that all the rest of the string must be included +in the extension. This regular expression matches ``foo.bar`` and +``autoexec.bat`` and ``sendmail.cf`` and ``printers.conf``. + +Now, consider complicating the problem a bit; what if you want to match +filenames where the extension is not ``bat``? Some incorrect attempts: + +``.*[.][^b].*$`` The first attempt above tries to exclude ``bat`` by requiring +that the first character of the extension is not a ``b``. This is wrong, +because the pattern also doesn't match ``foo.bar``. + +.. % $ + +``.*[.]([^b]..|.[^a].|..[^t])$`` + +.. % Messes up the HTML without the curly braces around \^ + +The expression gets messier when you try to patch up the first solution by +requiring one of the following cases to match: the first character of the +extension isn't ``b``; the second character isn't ``a``; or the third character +isn't ``t``. This accepts ``foo.bar`` and rejects ``autoexec.bat``, but it +requires a three-letter extension and won't accept a filename with a two-letter +extension such as ``sendmail.cf``. We'll complicate the pattern again in an +effort to fix it. + +``.*[.]([^b].?.?|.[^a]?.?|..?[^t]?)$`` + +In the third attempt, the second and third letters are all made optional in +order to allow matching extensions shorter than three characters, such as +``sendmail.cf``. + +The pattern's getting really complicated now, which makes it hard to read and +understand. Worse, if the problem changes and you want to exclude both ``bat`` +and ``exe`` as extensions, the pattern would get even more complicated and +confusing. + +A negative lookahead cuts through all this confusion: + +``.*[.](?!bat$).*$`` The negative lookahead means: if the expression ``bat`` +doesn't match at this point, try the rest of the pattern; if ``bat$`` does +match, the whole pattern will fail. The trailing ``$`` is required to ensure +that something like ``sample.batch``, where the extension only starts with +``bat``, will be allowed. + +.. % $ + +Excluding another filename extension is now easy; simply add it as an +alternative inside the assertion. The following pattern excludes filenames that +end in either ``bat`` or ``exe``: + +``.*[.](?!bat$|exe$).*$`` + +.. % $ + + +Modifying Strings +================= + +Up to this point, we've simply performed searches against a static string. +Regular expressions are also commonly used to modify strings in various ways, +using the following :class:`RegexObject` methods: + ++------------------+-----------------------------------------------+ +| Method/Attribute | Purpose | ++==================+===============================================+ +| ``split()`` | Split the string into a list, splitting it | +| | wherever the RE matches | ++------------------+-----------------------------------------------+ +| ``sub()`` | Find all substrings where the RE matches, and | +| | replace them with a different string | ++------------------+-----------------------------------------------+ +| ``subn()`` | Does the same thing as :meth:`sub`, but | +| | returns the new string and the number of | +| | replacements | ++------------------+-----------------------------------------------+ + + +Splitting Strings +----------------- + +The :meth:`split` method of a :class:`RegexObject` splits a string apart +wherever the RE matches, returning a list of the pieces. It's similar to the +:meth:`split` method of strings but provides much more generality in the +delimiters that you can split by; :meth:`split` only supports splitting by +whitespace or by a fixed string. As you'd expect, there's a module-level +:func:`re.split` function, too. + + +.. method:: .split(string [, maxsplit=0]) + :noindex: + + Split *string* by the matches of the regular expression. If capturing + parentheses are used in the RE, then their contents will also be returned as + part of the resulting list. If *maxsplit* is nonzero, at most *maxsplit* splits + are performed. + +You can limit the number of splits made, by passing a value for *maxsplit*. +When *maxsplit* is nonzero, at most *maxsplit* splits will be made, and the +remainder of the string is returned as the final element of the list. In the +following example, the delimiter is any sequence of non-alphanumeric characters. +:: + + >>> p = re.compile(r'\W+') + >>> p.split('This is a test, short and sweet, of split().') + ['This', 'is', 'a', 'test', 'short', 'and', 'sweet', 'of', 'split', ''] + >>> p.split('This is a test, short and sweet, of split().', 3) + ['This', 'is', 'a', 'test, short and sweet, of split().'] + +Sometimes you're not only interested in what the text between delimiters is, but +also need to know what the delimiter was. If capturing parentheses are used in +the RE, then their values are also returned as part of the list. Compare the +following calls:: + + >>> p = re.compile(r'\W+') + >>> p2 = re.compile(r'(\W+)') + >>> p.split('This... is a test.') + ['This', 'is', 'a', 'test', ''] + >>> p2.split('This... is a test.') + ['This', '... ', 'is', ' ', 'a', ' ', 'test', '.', ''] + +The module-level function :func:`re.split` adds the RE to be used as the first +argument, but is otherwise the same. :: + + >>> re.split('[\W]+', 'Words, words, words.') + ['Words', 'words', 'words', ''] + >>> re.split('([\W]+)', 'Words, words, words.') + ['Words', ', ', 'words', ', ', 'words', '.', ''] + >>> re.split('[\W]+', 'Words, words, words.', 1) + ['Words', 'words, words.'] + + +Search and Replace +------------------ + +Another common task is to find all the matches for a pattern, and replace them +with a different string. The :meth:`sub` method takes a replacement value, +which can be either a string or a function, and the string to be processed. + + +.. method:: .sub(replacement, string[, count=0]) + :noindex: + + Returns the string obtained by replacing the leftmost non-overlapping + occurrences of the RE in *string* by the replacement *replacement*. If the + pattern isn't found, *string* is returned unchanged. + + The optional argument *count* is the maximum number of pattern occurrences to be + replaced; *count* must be a non-negative integer. The default value of 0 means + to replace all occurrences. + +Here's a simple example of using the :meth:`sub` method. It replaces colour +names with the word ``colour``:: + + >>> p = re.compile( '(blue|white|red)') + >>> p.sub( 'colour', 'blue socks and red shoes') + 'colour socks and colour shoes' + >>> p.sub( 'colour', 'blue socks and red shoes', count=1) + 'colour socks and red shoes' + +The :meth:`subn` method does the same work, but returns a 2-tuple containing the +new string value and the number of replacements that were performed:: + + >>> p = re.compile( '(blue|white|red)') + >>> p.subn( 'colour', 'blue socks and red shoes') + ('colour socks and colour shoes', 2) + >>> p.subn( 'colour', 'no colours at all') + ('no colours at all', 0) + +Empty matches are replaced only when they're not adjacent to a previous match. +:: + + >>> p = re.compile('x*') + >>> p.sub('-', 'abxd') + '-a-b-d-' + +If *replacement* is a string, any backslash escapes in it are processed. That +is, ``\n`` is converted to a single newline character, ``\r`` is converted to a +carriage return, and so forth. Unknown escapes such as ``\j`` are left alone. +Backreferences, such as ``\6``, are replaced with the substring matched by the +corresponding group in the RE. This lets you incorporate portions of the +original text in the resulting replacement string. + +This example matches the word ``section`` followed by a string enclosed in +``{``, ``}``, and changes ``section`` to ``subsection``:: + + >>> p = re.compile('section{ ( [^}]* ) }', re.VERBOSE) + >>> p.sub(r'subsection{\1}','section{First} section{second}') + 'subsection{First} subsection{second}' + +There's also a syntax for referring to named groups as defined by the +``(?P...)`` syntax. ``\g`` will use the substring matched by the +group named ``name``, and ``\g`` uses the corresponding group number. +``\g<2>`` is therefore equivalent to ``\2``, but isn't ambiguous in a +replacement string such as ``\g<2>0``. (``\20`` would be interpreted as a +reference to group 20, not a reference to group 2 followed by the literal +character ``'0'``.) The following substitutions are all equivalent, but use all +three variations of the replacement string. :: + + >>> p = re.compile('section{ (?P [^}]* ) }', re.VERBOSE) + >>> p.sub(r'subsection{\1}','section{First}') + 'subsection{First}' + >>> p.sub(r'subsection{\g<1>}','section{First}') + 'subsection{First}' + >>> p.sub(r'subsection{\g}','section{First}') + 'subsection{First}' + +*replacement* can also be a function, which gives you even more control. If +*replacement* is a function, the function is called for every non-overlapping +occurrence of *pattern*. On each call, the function is passed a +:class:`MatchObject` argument for the match and can use this information to +compute the desired replacement string and return it. + +In the following example, the replacement function translates decimals into +hexadecimal:: + + >>> def hexrepl( match ): + ... "Return the hex string for a decimal number" + ... value = int( match.group() ) + ... return hex(value) + ... + >>> p = re.compile(r'\d+') + >>> p.sub(hexrepl, 'Call 65490 for printing, 49152 for user code.') + 'Call 0xffd2 for printing, 0xc000 for user code.' + +When using the module-level :func:`re.sub` function, the pattern is passed as +the first argument. The pattern may be a string or a :class:`RegexObject`; if +you need to specify regular expression flags, you must either use a +:class:`RegexObject` as the first parameter, or use embedded modifiers in the +pattern, e.g. ``sub("(?i)b+", "x", "bbbb BBBB")`` returns ``'x x'``. + + +Common Problems +=============== + +Regular expressions are a powerful tool for some applications, but in some ways +their behaviour isn't intuitive and at times they don't behave the way you may +expect them to. This section will point out some of the most common pitfalls. + + +Use String Methods +------------------ + +Sometimes using the :mod:`re` module is a mistake. If you're matching a fixed +string, or a single character class, and you're not using any :mod:`re` features +such as the :const:`IGNORECASE` flag, then the full power of regular expressions +may not be required. Strings have several methods for performing operations with +fixed strings and they're usually much faster, because the implementation is a +single small C loop that's been optimized for the purpose, instead of the large, +more generalized regular expression engine. + +One example might be replacing a single fixed string with another one; for +example, you might replace ``word`` with ``deed``. ``re.sub()`` seems like the +function to use for this, but consider the :meth:`replace` method. Note that +:func:`replace` will also replace ``word`` inside words, turning ``swordfish`` +into ``sdeedfish``, but the naive RE ``word`` would have done that, too. (To +avoid performing the substitution on parts of words, the pattern would have to +be ``\bword\b``, in order to require that ``word`` have a word boundary on +either side. This takes the job beyond :meth:`replace`'s abilities.) + +Another common task is deleting every occurrence of a single character from a +string or replacing it with another single character. You might do this with +something like ``re.sub('\n', ' ', S)``, but :meth:`translate` is capable of +doing both tasks and will be faster than any regular expression operation can +be. + +In short, before turning to the :mod:`re` module, consider whether your problem +can be solved with a faster and simpler string method. + + +match() versus search() +----------------------- + +The :func:`match` function only checks if the RE matches at the beginning of the +string while :func:`search` will scan forward through the string for a match. +It's important to keep this distinction in mind. Remember, :func:`match` will +only report a successful match which will start at 0; if the match wouldn't +start at zero, :func:`match` will *not* report it. :: + + >>> print re.match('super', 'superstition').span() + (0, 5) + >>> print re.match('super', 'insuperable') + None + +On the other hand, :func:`search` will scan forward through the string, +reporting the first match it finds. :: + + >>> print re.search('super', 'superstition').span() + (0, 5) + >>> print re.search('super', 'insuperable').span() + (2, 7) + +Sometimes you'll be tempted to keep using :func:`re.match`, and just add ``.*`` +to the front of your RE. Resist this temptation and use :func:`re.search` +instead. The regular expression compiler does some analysis of REs in order to +speed up the process of looking for a match. One such analysis figures out what +the first character of a match must be; for example, a pattern starting with +``Crow`` must match starting with a ``'C'``. The analysis lets the engine +quickly scan through the string looking for the starting character, only trying +the full match if a ``'C'`` is found. + +Adding ``.*`` defeats this optimization, requiring scanning to the end of the +string and then backtracking to find a match for the rest of the RE. Use +:func:`re.search` instead. + + +Greedy versus Non-Greedy +------------------------ + +When repeating a regular expression, as in ``a*``, the resulting action is to +consume as much of the pattern as possible. This fact often bites you when +you're trying to match a pair of balanced delimiters, such as the angle brackets +surrounding an HTML tag. The naive pattern for matching a single HTML tag +doesn't work because of the greedy nature of ``.*``. :: + + >>> s = 'Title' + >>> len(s) + 32 + >>> print re.match('<.*>', s).span() + (0, 32) + >>> print re.match('<.*>', s).group() + Title + +The RE matches the ``'<'`` in ````, and the ``.*`` consumes the rest of +the string. There's still more left in the RE, though, and the ``>`` can't +match at the end of the string, so the regular expression engine has to +backtrack character by character until it finds a match for the ``>``. The +final match extends from the ``'<'`` in ```` to the ``'>'`` in +````, which isn't what you want. + +In this case, the solution is to use the non-greedy qualifiers ``*?``, ``+?``, +``??``, or ``{m,n}?``, which match as *little* text as possible. In the above +example, the ``'>'`` is tried immediately after the first ``'<'`` matches, and +when it fails, the engine advances a character at a time, retrying the ``'>'`` +at every step. This produces just the right result:: + + >>> print re.match('<.*?>', s).group() + + +(Note that parsing HTML or XML with regular expressions is painful. +Quick-and-dirty patterns will handle common cases, but HTML and XML have special +cases that will break the obvious regular expression; by the time you've written +a regular expression that handles all of the possible cases, the patterns will +be *very* complicated. Use an HTML or XML parser module for such tasks.) + + +Not Using re.VERBOSE +-------------------- + +By now you've probably noticed that regular expressions are a very compact +notation, but they're not terribly readable. REs of moderate complexity can +become lengthy collections of backslashes, parentheses, and metacharacters, +making them difficult to read and understand. + +For such REs, specifying the ``re.VERBOSE`` flag when compiling the regular +expression can be helpful, because it allows you to format the regular +expression more clearly. + +The ``re.VERBOSE`` flag has several effects. Whitespace in the regular +expression that *isn't* inside a character class is ignored. This means that an +expression such as ``dog | cat`` is equivalent to the less readable ``dog|cat``, +but ``[a b]`` will still match the characters ``'a'``, ``'b'``, or a space. In +addition, you can also put comments inside a RE; comments extend from a ``#`` +character to the next newline. When used with triple-quoted strings, this +enables REs to be formatted more neatly:: + + pat = re.compile(r""" + \s* # Skip leading whitespace + (?P
[^:]+) # Header name + \s* : # Whitespace, and a colon + (?P.*?) # The header's value -- *? used to + # lose the following trailing whitespace + \s*$ # Trailing whitespace to end-of-line + """, re.VERBOSE) + +This is far more readable than: + +.. % $ + +:: + + pat = re.compile(r"\s*(?P
[^:]+)\s*:(?P.*?)\s*$") + +.. % $ + + +Feedback +======== + +Regular expressions are a complicated topic. Did this document help you +understand them? Were there parts that were unclear, or Problems you +encountered that weren't covered here? If so, please send suggestions for +improvements to the author. + +The most complete book on regular expressions is almost certainly Jeffrey +Friedl's Mastering Regular Expressions, published by O'Reilly. Unfortunately, +it exclusively concentrates on Perl and Java's flavours of regular expressions, +and doesn't contain any Python material at all, so it won't be useful as a +reference for programming in Python. (The first edition covered Python's +now-removed :mod:`regex` module, which won't help you much.) Consider checking +it out from your library. + + +.. rubric:: Footnotes + +.. [#] Introduced in Python 2.2.2. + diff --git a/Doc/howto/sockets.rst b/Doc/howto/sockets.rst new file mode 100644 index 0000000..dc05d32 --- /dev/null +++ b/Doc/howto/sockets.rst @@ -0,0 +1,421 @@ +**************************** + Socket Programming HOWTO +**************************** + +:Author: Gordon McMillan + + +.. topic:: Abstract + + Sockets are used nearly everywhere, but are one of the most severely + misunderstood technologies around. This is a 10,000 foot overview of sockets. + It's not really a tutorial - you'll still have work to do in getting things + operational. It doesn't cover the fine points (and there are a lot of them), but + I hope it will give you enough background to begin using them decently. + + +Sockets +======= + +Sockets are used nearly everywhere, but are one of the most severely +misunderstood technologies around. This is a 10,000 foot overview of sockets. +It's not really a tutorial - you'll still have work to do in getting things +working. It doesn't cover the fine points (and there are a lot of them), but I +hope it will give you enough background to begin using them decently. + +I'm only going to talk about INET sockets, but they account for at least 99% of +the sockets in use. And I'll only talk about STREAM sockets - unless you really +know what you're doing (in which case this HOWTO isn't for you!), you'll get +better behavior and performance from a STREAM socket than anything else. I will +try to clear up the mystery of what a socket is, as well as some hints on how to +work with blocking and non-blocking sockets. But I'll start by talking about +blocking sockets. You'll need to know how they work before dealing with +non-blocking sockets. + +Part of the trouble with understanding these things is that "socket" can mean a +number of subtly different things, depending on context. So first, let's make a +distinction between a "client" socket - an endpoint of a conversation, and a +"server" socket, which is more like a switchboard operator. The client +application (your browser, for example) uses "client" sockets exclusively; the +web server it's talking to uses both "server" sockets and "client" sockets. + + +History +------- + +Of the various forms of IPC (*Inter Process Communication*), sockets are by far +the most popular. On any given platform, there are likely to be other forms of +IPC that are faster, but for cross-platform communication, sockets are about the +only game in town. + +They were invented in Berkeley as part of the BSD flavor of Unix. They spread +like wildfire with the Internet. With good reason --- the combination of sockets +with INET makes talking to arbitrary machines around the world unbelievably easy +(at least compared to other schemes). + + +Creating a Socket +================= + +Roughly speaking, when you clicked on the link that brought you to this page, +your browser did something like the following:: + + #create an INET, STREAMing socket + s = socket.socket( + socket.AF_INET, socket.SOCK_STREAM) + #now connect to the web server on port 80 + # - the normal http port + s.connect(("www.mcmillan-inc.com", 80)) + +When the ``connect`` completes, the socket ``s`` can now be used to send in a +request for the text of this page. The same socket will read the reply, and then +be destroyed. That's right - destroyed. Client sockets are normally only used +for one exchange (or a small set of sequential exchanges). + +What happens in the web server is a bit more complex. First, the web server +creates a "server socket". :: + + #create an INET, STREAMing socket + serversocket = socket.socket( + socket.AF_INET, socket.SOCK_STREAM) + #bind the socket to a public host, + # and a well-known port + serversocket.bind((socket.gethostname(), 80)) + #become a server socket + serversocket.listen(5) + +A couple things to notice: we used ``socket.gethostname()`` so that the socket +would be visible to the outside world. If we had used ``s.bind(('', 80))`` or +``s.bind(('localhost', 80))`` or ``s.bind(('127.0.0.1', 80))`` we would still +have a "server" socket, but one that was only visible within the same machine. + +A second thing to note: low number ports are usually reserved for "well known" +services (HTTP, SNMP etc). If you're playing around, use a nice high number (4 +digits). + +Finally, the argument to ``listen`` tells the socket library that we want it to +queue up as many as 5 connect requests (the normal max) before refusing outside +connections. If the rest of the code is written properly, that should be plenty. + +OK, now we have a "server" socket, listening on port 80. Now we enter the +mainloop of the web server:: + + while 1: + #accept connections from outside + (clientsocket, address) = serversocket.accept() + #now do something with the clientsocket + #in this case, we'll pretend this is a threaded server + ct = client_thread(clientsocket) + ct.run() + +There's actually 3 general ways in which this loop could work - dispatching a +thread to handle ``clientsocket``, create a new process to handle +``clientsocket``, or restructure this app to use non-blocking sockets, and +mulitplex between our "server" socket and any active ``clientsocket``\ s using +``select``. More about that later. The important thing to understand now is +this: this is *all* a "server" socket does. It doesn't send any data. It doesn't +receive any data. It just produces "client" sockets. Each ``clientsocket`` is +created in response to some *other* "client" socket doing a ``connect()`` to the +host and port we're bound to. As soon as we've created that ``clientsocket``, we +go back to listening for more connections. The two "clients" are free to chat it +up - they are using some dynamically allocated port which will be recycled when +the conversation ends. + + +IPC +--- + +If you need fast IPC between two processes on one machine, you should look into +whatever form of shared memory the platform offers. A simple protocol based +around shared memory and locks or semaphores is by far the fastest technique. + +If you do decide to use sockets, bind the "server" socket to ``'localhost'``. On +most platforms, this will take a shortcut around a couple of layers of network +code and be quite a bit faster. + + +Using a Socket +============== + +The first thing to note, is that the web browser's "client" socket and the web +server's "client" socket are identical beasts. That is, this is a "peer to peer" +conversation. Or to put it another way, *as the designer, you will have to +decide what the rules of etiquette are for a conversation*. Normally, the +``connect``\ ing socket starts the conversation, by sending in a request, or +perhaps a signon. But that's a design decision - it's not a rule of sockets. + +Now there are two sets of verbs to use for communication. You can use ``send`` +and ``recv``, or you can transform your client socket into a file-like beast and +use ``read`` and ``write``. The latter is the way Java presents their sockets. +I'm not going to talk about it here, except to warn you that you need to use +``flush`` on sockets. These are buffered "files", and a common mistake is to +``write`` something, and then ``read`` for a reply. Without a ``flush`` in +there, you may wait forever for the reply, because the request may still be in +your output buffer. + +Now we come the major stumbling block of sockets - ``send`` and ``recv`` operate +on the network buffers. They do not necessarily handle all the bytes you hand +them (or expect from them), because their major focus is handling the network +buffers. In general, they return when the associated network buffers have been +filled (``send``) or emptied (``recv``). They then tell you how many bytes they +handled. It is *your* responsibility to call them again until your message has +been completely dealt with. + +When a ``recv`` returns 0 bytes, it means the other side has closed (or is in +the process of closing) the connection. You will not receive any more data on +this connection. Ever. You may be able to send data successfully; I'll talk +about that some on the next page. + +A protocol like HTTP uses a socket for only one transfer. The client sends a +request, the reads a reply. That's it. The socket is discarded. This means that +a client can detect the end of the reply by receiving 0 bytes. + +But if you plan to reuse your socket for further transfers, you need to realize +that *there is no "EOT" (End of Transfer) on a socket.* I repeat: if a socket +``send`` or ``recv`` returns after handling 0 bytes, the connection has been +broken. If the connection has *not* been broken, you may wait on a ``recv`` +forever, because the socket will *not* tell you that there's nothing more to +read (for now). Now if you think about that a bit, you'll come to realize a +fundamental truth of sockets: *messages must either be fixed length* (yuck), *or +be delimited* (shrug), *or indicate how long they are* (much better), *or end by +shutting down the connection*. The choice is entirely yours, (but some ways are +righter than others). + +Assuming you don't want to end the connection, the simplest solution is a fixed +length message:: + + class mysocket: + '''demonstration class only + - coded for clarity, not efficiency + ''' + + def __init__(self, sock=None): + if sock is None: + self.sock = socket.socket( + socket.AF_INET, socket.SOCK_STREAM) + else: + self.sock = sock + + def connect(self, host, port): + self.sock.connect((host, port)) + + def mysend(self, msg): + totalsent = 0 + while totalsent < MSGLEN: + sent = self.sock.send(msg[totalsent:]) + if sent == 0: + raise RuntimeError, \ + "socket connection broken" + totalsent = totalsent + sent + + def myreceive(self): + msg = '' + while len(msg) < MSGLEN: + chunk = self.sock.recv(MSGLEN-len(msg)) + if chunk == '': + raise RuntimeError, \ + "socket connection broken" + msg = msg + chunk + return msg + +The sending code here is usable for almost any messaging scheme - in Python you +send strings, and you can use ``len()`` to determine its length (even if it has +embedded ``\0`` characters). It's mostly the receiving code that gets more +complex. (And in C, it's not much worse, except you can't use ``strlen`` if the +message has embedded ``\0``\ s.) + +The easiest enhancement is to make the first character of the message an +indicator of message type, and have the type determine the length. Now you have +two ``recv``\ s - the first to get (at least) that first character so you can +look up the length, and the second in a loop to get the rest. If you decide to +go the delimited route, you'll be receiving in some arbitrary chunk size, (4096 +or 8192 is frequently a good match for network buffer sizes), and scanning what +you've received for a delimiter. + +One complication to be aware of: if your conversational protocol allows multiple +messages to be sent back to back (without some kind of reply), and you pass +``recv`` an arbitrary chunk size, you may end up reading the start of a +following message. You'll need to put that aside and hold onto it, until it's +needed. + +Prefixing the message with it's length (say, as 5 numeric characters) gets more +complex, because (believe it or not), you may not get all 5 characters in one +``recv``. In playing around, you'll get away with it; but in high network loads, +your code will very quickly break unless you use two ``recv`` loops - the first +to determine the length, the second to get the data part of the message. Nasty. +This is also when you'll discover that ``send`` does not always manage to get +rid of everything in one pass. And despite having read this, you will eventually +get bit by it! + +In the interests of space, building your character, (and preserving my +competitive position), these enhancements are left as an exercise for the +reader. Lets move on to cleaning up. + + +Binary Data +----------- + +It is perfectly possible to send binary data over a socket. The major problem is +that not all machines use the same formats for binary data. For example, a +Motorola chip will represent a 16 bit integer with the value 1 as the two hex +bytes 00 01. Intel and DEC, however, are byte-reversed - that same 1 is 01 00. +Socket libraries have calls for converting 16 and 32 bit integers - ``ntohl, +htonl, ntohs, htons`` where "n" means *network* and "h" means *host*, "s" means +*short* and "l" means *long*. Where network order is host order, these do +nothing, but where the machine is byte-reversed, these swap the bytes around +appropriately. + +In these days of 32 bit machines, the ascii representation of binary data is +frequently smaller than the binary representation. That's because a surprising +amount of the time, all those longs have the value 0, or maybe 1. The string "0" +would be two bytes, while binary is four. Of course, this doesn't fit well with +fixed-length messages. Decisions, decisions. + + +Disconnecting +============= + +Strictly speaking, you're supposed to use ``shutdown`` on a socket before you +``close`` it. The ``shutdown`` is an advisory to the socket at the other end. +Depending on the argument you pass it, it can mean "I'm not going to send +anymore, but I'll still listen", or "I'm not listening, good riddance!". Most +socket libraries, however, are so used to programmers neglecting to use this +piece of etiquette that normally a ``close`` is the same as ``shutdown(); +close()``. So in most situations, an explicit ``shutdown`` is not needed. + +One way to use ``shutdown`` effectively is in an HTTP-like exchange. The client +sends a request and then does a ``shutdown(1)``. This tells the server "This +client is done sending, but can still receive." The server can detect "EOF" by +a receive of 0 bytes. It can assume it has the complete request. The server +sends a reply. If the ``send`` completes successfully then, indeed, the client +was still receiving. + +Python takes the automatic shutdown a step further, and says that when a socket +is garbage collected, it will automatically do a ``close`` if it's needed. But +relying on this is a very bad habit. If your socket just disappears without +doing a ``close``, the socket at the other end may hang indefinitely, thinking +you're just being slow. *Please* ``close`` your sockets when you're done. + + +When Sockets Die +---------------- + +Probably the worst thing about using blocking sockets is what happens when the +other side comes down hard (without doing a ``close``). Your socket is likely to +hang. SOCKSTREAM is a reliable protocol, and it will wait a long, long time +before giving up on a connection. If you're using threads, the entire thread is +essentially dead. There's not much you can do about it. As long as you aren't +doing something dumb, like holding a lock while doing a blocking read, the +thread isn't really consuming much in the way of resources. Do *not* try to kill +the thread - part of the reason that threads are more efficient than processes +is that they avoid the overhead associated with the automatic recycling of +resources. In other words, if you do manage to kill the thread, your whole +process is likely to be screwed up. + + +Non-blocking Sockets +==================== + +If you've understood the preceeding, you already know most of what you need to +know about the mechanics of using sockets. You'll still use the same calls, in +much the same ways. It's just that, if you do it right, your app will be almost +inside-out. + +In Python, you use ``socket.setblocking(0)`` to make it non-blocking. In C, it's +more complex, (for one thing, you'll need to choose between the BSD flavor +``O_NONBLOCK`` and the almost indistinguishable Posix flavor ``O_NDELAY``, which +is completely different from ``TCP_NODELAY``), but it's the exact same idea. You +do this after creating the socket, but before using it. (Actually, if you're +nuts, you can switch back and forth.) + +The major mechanical difference is that ``send``, ``recv``, ``connect`` and +``accept`` can return without having done anything. You have (of course) a +number of choices. You can check return code and error codes and generally drive +yourself crazy. If you don't believe me, try it sometime. Your app will grow +large, buggy and suck CPU. So let's skip the brain-dead solutions and do it +right. + +Use ``select``. + +In C, coding ``select`` is fairly complex. In Python, it's a piece of cake, but +it's close enough to the C version that if you understand ``select`` in Python, +you'll have little trouble with it in C. :: + + ready_to_read, ready_to_write, in_error = \ + select.select( + potential_readers, + potential_writers, + potential_errs, + timeout) + +You pass ``select`` three lists: the first contains all sockets that you might +want to try reading; the second all the sockets you might want to try writing +to, and the last (normally left empty) those that you want to check for errors. +You should note that a socket can go into more than one list. The ``select`` +call is blocking, but you can give it a timeout. This is generally a sensible +thing to do - give it a nice long timeout (say a minute) unless you have good +reason to do otherwise. + +In return, you will get three lists. They have the sockets that are actually +readable, writable and in error. Each of these lists is a subset (possbily +empty) of the corresponding list you passed in. And if you put a socket in more +than one input list, it will only be (at most) in one output list. + +If a socket is in the output readable list, you can be +as-close-to-certain-as-we-ever-get-in-this-business that a ``recv`` on that +socket will return *something*. Same idea for the writable list. You'll be able +to send *something*. Maybe not all you want to, but *something* is better than +nothing. (Actually, any reasonably healthy socket will return as writable - it +just means outbound network buffer space is available.) + +If you have a "server" socket, put it in the potential_readers list. If it comes +out in the readable list, your ``accept`` will (almost certainly) work. If you +have created a new socket to ``connect`` to someone else, put it in the +ptoential_writers list. If it shows up in the writable list, you have a decent +chance that it has connected. + +One very nasty problem with ``select``: if somewhere in those input lists of +sockets is one which has died a nasty death, the ``select`` will fail. You then +need to loop through every single damn socket in all those lists and do a +``select([sock],[],[],0)`` until you find the bad one. That timeout of 0 means +it won't take long, but it's ugly. + +Actually, ``select`` can be handy even with blocking sockets. It's one way of +determining whether you will block - the socket returns as readable when there's +something in the buffers. However, this still doesn't help with the problem of +determining whether the other end is done, or just busy with something else. + +**Portability alert**: On Unix, ``select`` works both with the sockets and +files. Don't try this on Windows. On Windows, ``select`` works with sockets +only. Also note that in C, many of the more advanced socket options are done +differently on Windows. In fact, on Windows I usually use threads (which work +very, very well) with my sockets. Face it, if you want any kind of performance, +your code will look very different on Windows than on Unix. (I haven't the +foggiest how you do this stuff on a Mac.) + + +Performance +----------- + +There's no question that the fastest sockets code uses non-blocking sockets and +select to multiplex them. You can put together something that will saturate a +LAN connection without putting any strain on the CPU. The trouble is that an app +written this way can't do much of anything else - it needs to be ready to +shuffle bytes around at all times. + +Assuming that your app is actually supposed to do something more than that, +threading is the optimal solution, (and using non-blocking sockets will be +faster than using blocking sockets). Unfortunately, threading support in Unixes +varies both in API and quality. So the normal Unix solution is to fork a +subprocess to deal with each connection. The overhead for this is significant +(and don't do this on Windows - the overhead of process creation is enormous +there). It also means that unless each subprocess is completely independent, +you'll need to use another form of IPC, say a pipe, or shared memory and +semaphores, to communicate between the parent and child processes. + +Finally, remember that even though blocking sockets are somewhat slower than +non-blocking, in many cases they are the "right" solution. After all, if your +app is driven by the data it receives over a socket, there's not much sense in +complicating the logic just so your app can wait on ``select`` instead of +``recv``. + diff --git a/Doc/howto/unicode.rst b/Doc/howto/unicode.rst new file mode 100644 index 0000000..16bd5a8 --- /dev/null +++ b/Doc/howto/unicode.rst @@ -0,0 +1,732 @@ +***************** + Unicode HOWTO +***************** + +:Release: 1.02 + +This HOWTO discusses Python's support for Unicode, and explains various problems +that people commonly encounter when trying to work with Unicode. + +Introduction to Unicode +======================= + +History of Character Codes +-------------------------- + +In 1968, the American Standard Code for Information Interchange, better known by +its acronym ASCII, was standardized. ASCII defined numeric codes for various +characters, with the numeric values running from 0 to +127. For example, the lowercase letter 'a' is assigned 97 as its code +value. + +ASCII was an American-developed standard, so it only defined unaccented +characters. There was an 'e', but no 'é' or 'Í'. This meant that languages +which required accented characters couldn't be faithfully represented in ASCII. +(Actually the missing accents matter for English, too, which contains words such +as 'naïve' and 'café', and some publications have house styles which require +spellings such as 'coöperate'.) + +For a while people just wrote programs that didn't display accents. I remember +looking at Apple ][ BASIC programs, published in French-language publications in +the mid-1980s, that had lines like these:: + + PRINT "FICHER EST COMPLETE." + PRINT "CARACTERE NON ACCEPTE." + +Those messages should contain accents, and they just look wrong to someone who +can read French. + +In the 1980s, almost all personal computers were 8-bit, meaning that bytes could +hold values ranging from 0 to 255. ASCII codes only went up to 127, so some +machines assigned values between 128 and 255 to accented characters. Different +machines had different codes, however, which led to problems exchanging files. +Eventually various commonly used sets of values for the 128-255 range emerged. +Some were true standards, defined by the International Standards Organization, +and some were **de facto** conventions that were invented by one company or +another and managed to catch on. + +255 characters aren't very many. For example, you can't fit both the accented +characters used in Western Europe and the Cyrillic alphabet used for Russian +into the 128-255 range because there are more than 127 such characters. + +You could write files using different codes (all your Russian files in a coding +system called KOI8, all your French files in a different coding system called +Latin1), but what if you wanted to write a French document that quotes some +Russian text? In the 1980s people began to want to solve this problem, and the +Unicode standardization effort began. + +Unicode started out using 16-bit characters instead of 8-bit characters. 16 +bits means you have 2^16 = 65,536 distinct values available, making it possible +to represent many different characters from many different alphabets; an initial +goal was to have Unicode contain the alphabets for every single human language. +It turns out that even 16 bits isn't enough to meet that goal, and the modern +Unicode specification uses a wider range of codes, 0-1,114,111 (0x10ffff in +base-16). + +There's a related ISO standard, ISO 10646. Unicode and ISO 10646 were +originally separate efforts, but the specifications were merged with the 1.1 +revision of Unicode. + +(This discussion of Unicode's history is highly simplified. I don't think the +average Python programmer needs to worry about the historical details; consult +the Unicode consortium site listed in the References for more information.) + + +Definitions +----------- + +A **character** is the smallest possible component of a text. 'A', 'B', 'C', +etc., are all different characters. So are 'È' and 'Í'. Characters are +abstractions, and vary depending on the language or context you're talking +about. For example, the symbol for ohms (Ω) is usually drawn much like the +capital letter omega (Ω) in the Greek alphabet (they may even be the same in +some fonts), but these are two different characters that have different +meanings. + +The Unicode standard describes how characters are represented by **code +points**. A code point is an integer value, usually denoted in base 16. In the +standard, a code point is written using the notation U+12ca to mean the +character with value 0x12ca (4810 decimal). The Unicode standard contains a lot +of tables listing characters and their corresponding code points:: + + 0061 'a'; LATIN SMALL LETTER A + 0062 'b'; LATIN SMALL LETTER B + 0063 'c'; LATIN SMALL LETTER C + ... + 007B '{'; LEFT CURLY BRACKET + +Strictly, these definitions imply that it's meaningless to say 'this is +character U+12ca'. U+12ca is a code point, which represents some particular +character; in this case, it represents the character 'ETHIOPIC SYLLABLE WI'. In +informal contexts, this distinction between code points and characters will +sometimes be forgotten. + +A character is represented on a screen or on paper by a set of graphical +elements that's called a **glyph**. The glyph for an uppercase A, for example, +is two diagonal strokes and a horizontal stroke, though the exact details will +depend on the font being used. Most Python code doesn't need to worry about +glyphs; figuring out the correct glyph to display is generally the job of a GUI +toolkit or a terminal's font renderer. + + +Encodings +--------- + +To summarize the previous section: a Unicode string is a sequence of code +points, which are numbers from 0 to 0x10ffff. This sequence needs to be +represented as a set of bytes (meaning, values from 0-255) in memory. The rules +for translating a Unicode string into a sequence of bytes are called an +**encoding**. + +The first encoding you might think of is an array of 32-bit integers. In this +representation, the string "Python" would look like this:: + + P y t h o n + 0x50 00 00 00 79 00 00 00 74 00 00 00 68 00 00 00 6f 00 00 00 6e 00 00 00 + 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 + +This representation is straightforward but using it presents a number of +problems. + +1. It's not portable; different processors order the bytes differently. + +2. It's very wasteful of space. In most texts, the majority of the code points + are less than 127, or less than 255, so a lot of space is occupied by zero + bytes. The above string takes 24 bytes compared to the 6 bytes needed for an + ASCII representation. Increased RAM usage doesn't matter too much (desktop + computers have megabytes of RAM, and strings aren't usually that large), but + expanding our usage of disk and network bandwidth by a factor of 4 is + intolerable. + +3. It's not compatible with existing C functions such as ``strlen()``, so a new + family of wide string functions would need to be used. + +4. Many Internet standards are defined in terms of textual data, and can't + handle content with embedded zero bytes. + +Generally people don't use this encoding, instead choosing other encodings that +are more efficient and convenient. + +Encodings don't have to handle every possible Unicode character, and most +encodings don't. For example, Python's default encoding is the 'ascii' +encoding. The rules for converting a Unicode string into the ASCII encoding are +simple; for each code point: + +1. If the code point is < 128, each byte is the same as the value of the code + point. + +2. If the code point is 128 or greater, the Unicode string can't be represented + in this encoding. (Python raises a :exc:`UnicodeEncodeError` exception in this + case.) + +Latin-1, also known as ISO-8859-1, is a similar encoding. Unicode code points +0-255 are identical to the Latin-1 values, so converting to this encoding simply +requires converting code points to byte values; if a code point larger than 255 +is encountered, the string can't be encoded into Latin-1. + +Encodings don't have to be simple one-to-one mappings like Latin-1. Consider +IBM's EBCDIC, which was used on IBM mainframes. Letter values weren't in one +block: 'a' through 'i' had values from 129 to 137, but 'j' through 'r' were 145 +through 153. If you wanted to use EBCDIC as an encoding, you'd probably use +some sort of lookup table to perform the conversion, but this is largely an +internal detail. + +UTF-8 is one of the most commonly used encodings. UTF stands for "Unicode +Transformation Format", and the '8' means that 8-bit numbers are used in the +encoding. (There's also a UTF-16 encoding, but it's less frequently used than +UTF-8.) UTF-8 uses the following rules: + +1. If the code point is <128, it's represented by the corresponding byte value. +2. If the code point is between 128 and 0x7ff, it's turned into two byte values + between 128 and 255. +3. Code points >0x7ff are turned into three- or four-byte sequences, where each + byte of the sequence is between 128 and 255. + +UTF-8 has several convenient properties: + +1. It can handle any Unicode code point. +2. A Unicode string is turned into a string of bytes containing no embedded zero + bytes. This avoids byte-ordering issues, and means UTF-8 strings can be + processed by C functions such as ``strcpy()`` and sent through protocols that + can't handle zero bytes. +3. A string of ASCII text is also valid UTF-8 text. +4. UTF-8 is fairly compact; the majority of code points are turned into two + bytes, and values less than 128 occupy only a single byte. +5. If bytes are corrupted or lost, it's possible to determine the start of the + next UTF-8-encoded code point and resynchronize. It's also unlikely that + random 8-bit data will look like valid UTF-8. + + + +References +---------- + +The Unicode Consortium site at has character charts, a +glossary, and PDF versions of the Unicode specification. Be prepared for some +difficult reading. is a chronology of the +origin and development of Unicode. + +To help understand the standard, Jukka Korpela has written an introductory guide +to reading the Unicode character tables, available at +. + +Roman Czyborra wrote another explanation of Unicode's basic principles; it's at +. Czyborra has written a number of +other Unicode-related documentation, available from . + +Two other good introductory articles were written by Joel Spolsky + and Jason Orendorff +. If this introduction didn't make +things clear to you, you should try reading one of these alternate articles +before continuing. + +Wikipedia entries are often helpful; see the entries for "character encoding" + and UTF-8 +, for example. + + +Python's Unicode Support +======================== + +Now that you've learned the rudiments of Unicode, we can look at Python's +Unicode features. + + +The Unicode Type +---------------- + +Unicode strings are expressed as instances of the :class:`unicode` type, one of +Python's repertoire of built-in types. It derives from an abstract type called +:class:`basestring`, which is also an ancestor of the :class:`str` type; you can +therefore check if a value is a string type with ``isinstance(value, +basestring)``. Under the hood, Python represents Unicode strings as either 16- +or 32-bit integers, depending on how the Python interpreter was compiled. + +The :func:`unicode` constructor has the signature ``unicode(string[, encoding, +errors])``. All of its arguments should be 8-bit strings. The first argument +is converted to Unicode using the specified encoding; if you leave off the +``encoding`` argument, the ASCII encoding is used for the conversion, so +characters greater than 127 will be treated as errors:: + + >>> unicode('abcdef') + u'abcdef' + >>> s = unicode('abcdef') + >>> type(s) + + >>> unicode('abcdef' + chr(255)) + Traceback (most recent call last): + File "", line 1, in ? + UnicodeDecodeError: 'ascii' codec can't decode byte 0xff in position 6: + ordinal not in range(128) + +The ``errors`` argument specifies the response when the input string can't be +converted according to the encoding's rules. Legal values for this argument are +'strict' (raise a ``UnicodeDecodeError`` exception), 'replace' (add U+FFFD, +'REPLACEMENT CHARACTER'), or 'ignore' (just leave the character out of the +Unicode result). The following examples show the differences:: + + >>> unicode('\x80abc', errors='strict') + Traceback (most recent call last): + File "", line 1, in ? + UnicodeDecodeError: 'ascii' codec can't decode byte 0x80 in position 0: + ordinal not in range(128) + >>> unicode('\x80abc', errors='replace') + u'\ufffdabc' + >>> unicode('\x80abc', errors='ignore') + u'abc' + +Encodings are specified as strings containing the encoding's name. Python 2.4 +comes with roughly 100 different encodings; see the Python Library Reference at + for a list. Some encodings +have multiple names; for example, 'latin-1', 'iso_8859_1' and '8859' are all +synonyms for the same encoding. + +One-character Unicode strings can also be created with the :func:`unichr` +built-in function, which takes integers and returns a Unicode string of length 1 +that contains the corresponding code point. The reverse operation is the +built-in :func:`ord` function that takes a one-character Unicode string and +returns the code point value:: + + >>> unichr(40960) + u'\ua000' + >>> ord(u'\ua000') + 40960 + +Instances of the :class:`unicode` type have many of the same methods as the +8-bit string type for operations such as searching and formatting:: + + >>> s = u'Was ever feather so lightly blown to and fro as this multitude?' + >>> s.count('e') + 5 + >>> s.find('feather') + 9 + >>> s.find('bird') + -1 + >>> s.replace('feather', 'sand') + u'Was ever sand so lightly blown to and fro as this multitude?' + >>> s.upper() + u'WAS EVER FEATHER SO LIGHTLY BLOWN TO AND FRO AS THIS MULTITUDE?' + +Note that the arguments to these methods can be Unicode strings or 8-bit +strings. 8-bit strings will be converted to Unicode before carrying out the +operation; Python's default ASCII encoding will be used, so characters greater +than 127 will cause an exception:: + + >>> s.find('Was\x9f') + Traceback (most recent call last): + File "", line 1, in ? + UnicodeDecodeError: 'ascii' codec can't decode byte 0x9f in position 3: ordinal not in range(128) + >>> s.find(u'Was\x9f') + -1 + +Much Python code that operates on strings will therefore work with Unicode +strings without requiring any changes to the code. (Input and output code needs +more updating for Unicode; more on this later.) + +Another important method is ``.encode([encoding], [errors='strict'])``, which +returns an 8-bit string version of the Unicode string, encoded in the requested +encoding. The ``errors`` parameter is the same as the parameter of the +``unicode()`` constructor, with one additional possibility; as well as 'strict', +'ignore', and 'replace', you can also pass 'xmlcharrefreplace' which uses XML's +character references. The following example shows the different results:: + + >>> u = unichr(40960) + u'abcd' + unichr(1972) + >>> u.encode('utf-8') + '\xea\x80\x80abcd\xde\xb4' + >>> u.encode('ascii') + Traceback (most recent call last): + File "", line 1, in ? + UnicodeEncodeError: 'ascii' codec can't encode character '\ua000' in position 0: ordinal not in range(128) + >>> u.encode('ascii', 'ignore') + 'abcd' + >>> u.encode('ascii', 'replace') + '?abcd?' + >>> u.encode('ascii', 'xmlcharrefreplace') + 'ꀀabcd޴' + +Python's 8-bit strings have a ``.decode([encoding], [errors])`` method that +interprets the string using the given encoding:: + + >>> u = unichr(40960) + u'abcd' + unichr(1972) # Assemble a string + >>> utf8_version = u.encode('utf-8') # Encode as UTF-8 + >>> type(utf8_version), utf8_version + (, '\xea\x80\x80abcd\xde\xb4') + >>> u2 = utf8_version.decode('utf-8') # Decode using UTF-8 + >>> u == u2 # The two strings match + True + +The low-level routines for registering and accessing the available encodings are +found in the :mod:`codecs` module. However, the encoding and decoding functions +returned by this module are usually more low-level than is comfortable, so I'm +not going to describe the :mod:`codecs` module here. If you need to implement a +completely new encoding, you'll need to learn about the :mod:`codecs` module +interfaces, but implementing encodings is a specialized task that also won't be +covered here. Consult the Python documentation to learn more about this module. + +The most commonly used part of the :mod:`codecs` module is the +:func:`codecs.open` function which will be discussed in the section on input and +output. + + +Unicode Literals in Python Source Code +-------------------------------------- + +In Python source code, Unicode literals are written as strings prefixed with the +'u' or 'U' character: ``u'abcdefghijk'``. Specific code points can be written +using the ``\u`` escape sequence, which is followed by four hex digits giving +the code point. The ``\U`` escape sequence is similar, but expects 8 hex +digits, not 4. + +Unicode literals can also use the same escape sequences as 8-bit strings, +including ``\x``, but ``\x`` only takes two hex digits so it can't express an +arbitrary code point. Octal escapes can go up to U+01ff, which is octal 777. + +:: + + >>> s = u"a\xac\u1234\u20ac\U00008000" + ^^^^ two-digit hex escape + ^^^^^^ four-digit Unicode escape + ^^^^^^^^^^ eight-digit Unicode escape + >>> for c in s: print ord(c), + ... + 97 172 4660 8364 32768 + +Using escape sequences for code points greater than 127 is fine in small doses, +but becomes an annoyance if you're using many accented characters, as you would +in a program with messages in French or some other accent-using language. You +can also assemble strings using the :func:`unichr` built-in function, but this is +even more tedious. + +Ideally, you'd want to be able to write literals in your language's natural +encoding. You could then edit Python source code with your favorite editor +which would display the accented characters naturally, and have the right +characters used at runtime. + +Python supports writing Unicode literals in any encoding, but you have to +declare the encoding being used. This is done by including a special comment as +either the first or second line of the source file:: + + #!/usr/bin/env python + # -*- coding: latin-1 -*- + + u = u'abcdé' + print ord(u[-1]) + +The syntax is inspired by Emacs's notation for specifying variables local to a +file. Emacs supports many different variables, but Python only supports +'coding'. The ``-*-`` symbols indicate that the comment is special; within +them, you must supply the name ``coding`` and the name of your chosen encoding, +separated by ``':'``. + +If you don't include such a comment, the default encoding used will be ASCII. +Versions of Python before 2.4 were Euro-centric and assumed Latin-1 as a default +encoding for string literals; in Python 2.4, characters greater than 127 still +work but result in a warning. For example, the following program has no +encoding declaration:: + + #!/usr/bin/env python + u = u'abcdé' + print ord(u[-1]) + +When you run it with Python 2.4, it will output the following warning:: + + amk:~$ python p263.py + sys:1: DeprecationWarning: Non-ASCII character '\xe9' + in file p263.py on line 2, but no encoding declared; + see http://www.python.org/peps/pep-0263.html for details + + +Unicode Properties +------------------ + +The Unicode specification includes a database of information about code points. +For each code point that's defined, the information includes the character's +name, its category, the numeric value if applicable (Unicode has characters +representing the Roman numerals and fractions such as one-third and +four-fifths). There are also properties related to the code point's use in +bidirectional text and other display-related properties. + +The following program displays some information about several characters, and +prints the numeric value of one particular character:: + + import unicodedata + + u = unichr(233) + unichr(0x0bf2) + unichr(3972) + unichr(6000) + unichr(13231) + + for i, c in enumerate(u): + print i, '%04x' % ord(c), unicodedata.category(c), + print unicodedata.name(c) + + # Get numeric value of second character + print unicodedata.numeric(u[1]) + +When run, this prints:: + + 0 00e9 Ll LATIN SMALL LETTER E WITH ACUTE + 1 0bf2 No TAMIL NUMBER ONE THOUSAND + 2 0f84 Mn TIBETAN MARK HALANTA + 3 1770 Lo TAGBANWA LETTER SA + 4 33af So SQUARE RAD OVER S SQUARED + 1000.0 + +The category codes are abbreviations describing the nature of the character. +These are grouped into categories such as "Letter", "Number", "Punctuation", or +"Symbol", which in turn are broken up into subcategories. To take the codes +from the above output, ``'Ll'`` means 'Letter, lowercase', ``'No'`` means +"Number, other", ``'Mn'`` is "Mark, nonspacing", and ``'So'`` is "Symbol, +other". See + for a +list of category codes. + +References +---------- + +The Unicode and 8-bit string types are described in the Python library reference +at :ref:`typesseq`. + +The documentation for the :mod:`unicodedata` module. + +The documentation for the :mod:`codecs` module. + +Marc-André Lemburg gave a presentation at EuroPython 2002 titled "Python and +Unicode". A PDF version of his slides is available at +, and is an +excellent overview of the design of Python's Unicode features. + + +Reading and Writing Unicode Data +================================ + +Once you've written some code that works with Unicode data, the next problem is +input/output. How do you get Unicode strings into your program, and how do you +convert Unicode into a form suitable for storage or transmission? + +It's possible that you may not need to do anything depending on your input +sources and output destinations; you should check whether the libraries used in +your application support Unicode natively. XML parsers often return Unicode +data, for example. Many relational databases also support Unicode-valued +columns and can return Unicode values from an SQL query. + +Unicode data is usually converted to a particular encoding before it gets +written to disk or sent over a socket. It's possible to do all the work +yourself: open a file, read an 8-bit string from it, and convert the string with +``unicode(str, encoding)``. However, the manual approach is not recommended. + +One problem is the multi-byte nature of encodings; one Unicode character can be +represented by several bytes. If you want to read the file in arbitrary-sized +chunks (say, 1K or 4K), you need to write error-handling code to catch the case +where only part of the bytes encoding a single Unicode character are read at the +end of a chunk. One solution would be to read the entire file into memory and +then perform the decoding, but that prevents you from working with files that +are extremely large; if you need to read a 2Gb file, you need 2Gb of RAM. +(More, really, since for at least a moment you'd need to have both the encoded +string and its Unicode version in memory.) + +The solution would be to use the low-level decoding interface to catch the case +of partial coding sequences. The work of implementing this has already been +done for you: the :mod:`codecs` module includes a version of the :func:`open` +function that returns a file-like object that assumes the file's contents are in +a specified encoding and accepts Unicode parameters for methods such as +``.read()`` and ``.write()``. + +The function's parameters are ``open(filename, mode='rb', encoding=None, +errors='strict', buffering=1)``. ``mode`` can be ``'r'``, ``'w'``, or ``'a'``, +just like the corresponding parameter to the regular built-in ``open()`` +function; add a ``'+'`` to update the file. ``buffering`` is similarly parallel +to the standard function's parameter. ``encoding`` is a string giving the +encoding to use; if it's left as ``None``, a regular Python file object that +accepts 8-bit strings is returned. Otherwise, a wrapper object is returned, and +data written to or read from the wrapper object will be converted as needed. +``errors`` specifies the action for encoding errors and can be one of the usual +values of 'strict', 'ignore', and 'replace'. + +Reading Unicode from a file is therefore simple:: + + import codecs + f = codecs.open('unicode.rst', encoding='utf-8') + for line in f: + print repr(line) + +It's also possible to open files in update mode, allowing both reading and +writing:: + + f = codecs.open('test', encoding='utf-8', mode='w+') + f.write(u'\u4500 blah blah blah\n') + f.seek(0) + print repr(f.readline()[:1]) + f.close() + +Unicode character U+FEFF is used as a byte-order mark (BOM), and is often +written as the first character of a file in order to assist with autodetection +of the file's byte ordering. Some encodings, such as UTF-16, expect a BOM to be +present at the start of a file; when such an encoding is used, the BOM will be +automatically written as the first character and will be silently dropped when +the file is read. There are variants of these encodings, such as 'utf-16-le' +and 'utf-16-be' for little-endian and big-endian encodings, that specify one +particular byte ordering and don't skip the BOM. + + +Unicode filenames +----------------- + +Most of the operating systems in common use today support filenames that contain +arbitrary Unicode characters. Usually this is implemented by converting the +Unicode string into some encoding that varies depending on the system. For +example, MacOS X uses UTF-8 while Windows uses a configurable encoding; on +Windows, Python uses the name "mbcs" to refer to whatever the currently +configured encoding is. On Unix systems, there will only be a filesystem +encoding if you've set the ``LANG`` or ``LC_CTYPE`` environment variables; if +you haven't, the default encoding is ASCII. + +The :func:`sys.getfilesystemencoding` function returns the encoding to use on +your current system, in case you want to do the encoding manually, but there's +not much reason to bother. When opening a file for reading or writing, you can +usually just provide the Unicode string as the filename, and it will be +automatically converted to the right encoding for you:: + + filename = u'filename\u4500abc' + f = open(filename, 'w') + f.write('blah\n') + f.close() + +Functions in the :mod:`os` module such as :func:`os.stat` will also accept Unicode +filenames. + +:func:`os.listdir`, which returns filenames, raises an issue: should it return +the Unicode version of filenames, or should it return 8-bit strings containing +the encoded versions? :func:`os.listdir` will do both, depending on whether you +provided the directory path as an 8-bit string or a Unicode string. If you pass +a Unicode string as the path, filenames will be decoded using the filesystem's +encoding and a list of Unicode strings will be returned, while passing an 8-bit +path will return the 8-bit versions of the filenames. For example, assuming the +default filesystem encoding is UTF-8, running the following program:: + + fn = u'filename\u4500abc' + f = open(fn, 'w') + f.close() + + import os + print os.listdir('.') + print os.listdir(u'.') + +will produce the following output:: + + amk:~$ python t.py + ['.svn', 'filename\xe4\x94\x80abc', ...] + [u'.svn', u'filename\u4500abc', ...] + +The first list contains UTF-8-encoded filenames, and the second list contains +the Unicode versions. + + + +Tips for Writing Unicode-aware Programs +--------------------------------------- + +This section provides some suggestions on writing software that deals with +Unicode. + +The most important tip is: + + Software should only work with Unicode strings internally, converting to a + particular encoding on output. + +If you attempt to write processing functions that accept both Unicode and 8-bit +strings, you will find your program vulnerable to bugs wherever you combine the +two different kinds of strings. Python's default encoding is ASCII, so whenever +a character with an ASCII value > 127 is in the input data, you'll get a +:exc:`UnicodeDecodeError` because that character can't be handled by the ASCII +encoding. + +It's easy to miss such problems if you only test your software with data that +doesn't contain any accents; everything will seem to work, but there's actually +a bug in your program waiting for the first user who attempts to use characters +> 127. A second tip, therefore, is: + + Include characters > 127 and, even better, characters > 255 in your test + data. + +When using data coming from a web browser or some other untrusted source, a +common technique is to check for illegal characters in a string before using the +string in a generated command line or storing it in a database. If you're doing +this, be careful to check the string once it's in the form that will be used or +stored; it's possible for encodings to be used to disguise characters. This is +especially true if the input data also specifies the encoding; many encodings +leave the commonly checked-for characters alone, but Python includes some +encodings such as ``'base64'`` that modify every single character. + +For example, let's say you have a content management system that takes a Unicode +filename, and you want to disallow paths with a '/' character. You might write +this code:: + + def read_file (filename, encoding): + if '/' in filename: + raise ValueError("'/' not allowed in filenames") + unicode_name = filename.decode(encoding) + f = open(unicode_name, 'r') + # ... return contents of file ... + +However, if an attacker could specify the ``'base64'`` encoding, they could pass +``'L2V0Yy9wYXNzd2Q='``, which is the base-64 encoded form of the string +``'/etc/passwd'``, to read a system file. The above code looks for ``'/'`` +characters in the encoded form and misses the dangerous character in the +resulting decoded form. + +References +---------- + +The PDF slides for Marc-André Lemburg's presentation "Writing Unicode-aware +Applications in Python" are available at + +and discuss questions of character encodings as well as how to internationalize +and localize an application. + + +Revision History and Acknowledgements +===================================== + +Thanks to the following people who have noted errors or offered suggestions on +this article: Nicholas Bastin, Marius Gedminas, Kent Johnson, Ken Krugler, +Marc-André Lemburg, Martin von Löwis, Chad Whitacre. + +Version 1.0: posted August 5 2005. + +Version 1.01: posted August 7 2005. Corrects factual and markup errors; adds +several links. + +Version 1.02: posted August 16 2005. Corrects factual errors. + + +.. comment Additional topic: building Python w/ UCS2 or UCS4 support +.. comment Describe obscure -U switch somewhere? +.. comment Describe use of codecs.StreamRecoder and StreamReaderWriter + +.. comment + Original outline: + + - [ ] Unicode introduction + - [ ] ASCII + - [ ] Terms + - [ ] Character + - [ ] Code point + - [ ] Encodings + - [ ] Common encodings: ASCII, Latin-1, UTF-8 + - [ ] Unicode Python type + - [ ] Writing unicode literals + - [ ] Obscurity: -U switch + - [ ] Built-ins + - [ ] unichr() + - [ ] ord() + - [ ] unicode() constructor + - [ ] Unicode type + - [ ] encode(), decode() methods + - [ ] Unicodedata module for character properties + - [ ] I/O + - [ ] Reading/writing Unicode data into files + - [ ] Byte-order marks + - [ ] Unicode filenames + - [ ] Writing Unicode programs + - [ ] Do everything in Unicode + - [ ] Declaring source code encodings (PEP 263) + - [ ] Other issues + - [ ] Building Python (UCS2, UCS4) diff --git a/Doc/howto/urllib2.rst b/Doc/howto/urllib2.rst new file mode 100644 index 0000000..dc20b02 --- /dev/null +++ b/Doc/howto/urllib2.rst @@ -0,0 +1,578 @@ +************************************************ + HOWTO Fetch Internet Resources Using urllib2 +************************************************ + +:Author: `Michael Foord `_ + +.. note:: + + There is an French translation of an earlier revision of this + HOWTO, available at `urllib2 - Le Manuel manquant + `_. + + + +Introduction +============ + +.. sidebar:: Related Articles + + You may also find useful the following article on fetching web resources + with Python : + + * `Basic Authentication `_ + + A tutorial on *Basic Authentication*, with examples in Python. + +**urllib2** is a `Python `_ module for fetching URLs +(Uniform Resource Locators). It offers a very simple interface, in the form of +the *urlopen* function. This is capable of fetching URLs using a variety of +different protocols. It also offers a slightly more complex interface for +handling common situations - like basic authentication, cookies, proxies and so +on. These are provided by objects called handlers and openers. + +urllib2 supports fetching URLs for many "URL schemes" (identified by the string +before the ":" in URL - for example "ftp" is the URL scheme of +"ftp://python.org/") using their associated network protocols (e.g. FTP, HTTP). +This tutorial focuses on the most common case, HTTP. + +For straightforward situations *urlopen* is very easy to use. But as soon as you +encounter errors or non-trivial cases when opening HTTP URLs, you will need some +understanding of the HyperText Transfer Protocol. The most comprehensive and +authoritative reference to HTTP is :rfc:`2616`. This is a technical document and +not intended to be easy to read. This HOWTO aims to illustrate using *urllib2*, +with enough detail about HTTP to help you through. It is not intended to replace +the :mod:`urllib2` docs, but is supplementary to them. + + +Fetching URLs +============= + +The simplest way to use urllib2 is as follows:: + + import urllib2 + response = urllib2.urlopen('http://python.org/') + html = response.read() + +Many uses of urllib2 will be that simple (note that instead of an 'http:' URL we +could have used an URL starting with 'ftp:', 'file:', etc.). However, it's the +purpose of this tutorial to explain the more complicated cases, concentrating on +HTTP. + +HTTP is based on requests and responses - the client makes requests and servers +send responses. urllib2 mirrors this with a ``Request`` object which represents +the HTTP request you are making. In its simplest form you create a Request +object that specifies the URL you want to fetch. Calling ``urlopen`` with this +Request object returns a response object for the URL requested. This response is +a file-like object, which means you can for example call ``.read()`` on the +response:: + + import urllib2 + + req = urllib2.Request('http://www.voidspace.org.uk') + response = urllib2.urlopen(req) + the_page = response.read() + +Note that urllib2 makes use of the same Request interface to handle all URL +schemes. For example, you can make an FTP request like so:: + + req = urllib2.Request('ftp://example.com/') + +In the case of HTTP, there are two extra things that Request objects allow you +to do: First, you can pass data to be sent to the server. Second, you can pass +extra information ("metadata") *about* the data or the about request itself, to +the server - this information is sent as HTTP "headers". Let's look at each of +these in turn. + +Data +---- + +Sometimes you want to send data to a URL (often the URL will refer to a CGI +(Common Gateway Interface) script [#]_ or other web application). With HTTP, +this is often done using what's known as a **POST** request. This is often what +your browser does when you submit a HTML form that you filled in on the web. Not +all POSTs have to come from forms: you can use a POST to transmit arbitrary data +to your own application. In the common case of HTML forms, the data needs to be +encoded in a standard way, and then passed to the Request object as the ``data`` +argument. The encoding is done using a function from the ``urllib`` library +*not* from ``urllib2``. :: + + import urllib + import urllib2 + + url = 'http://www.someserver.com/cgi-bin/register.cgi' + values = {'name' : 'Michael Foord', + 'location' : 'Northampton', + 'language' : 'Python' } + + data = urllib.urlencode(values) + req = urllib2.Request(url, data) + response = urllib2.urlopen(req) + the_page = response.read() + +Note that other encodings are sometimes required (e.g. for file upload from HTML +forms - see `HTML Specification, Form Submission +`_ for more +details). + +If you do not pass the ``data`` argument, urllib2 uses a **GET** request. One +way in which GET and POST requests differ is that POST requests often have +"side-effects": they change the state of the system in some way (for example by +placing an order with the website for a hundredweight of tinned spam to be +delivered to your door). Though the HTTP standard makes it clear that POSTs are +intended to *always* cause side-effects, and GET requests *never* to cause +side-effects, nothing prevents a GET request from having side-effects, nor a +POST requests from having no side-effects. Data can also be passed in an HTTP +GET request by encoding it in the URL itself. + +This is done as follows:: + + >>> import urllib2 + >>> import urllib + >>> data = {} + >>> data['name'] = 'Somebody Here' + >>> data['location'] = 'Northampton' + >>> data['language'] = 'Python' + >>> url_values = urllib.urlencode(data) + >>> print url_values + name=Somebody+Here&language=Python&location=Northampton + >>> url = 'http://www.example.com/example.cgi' + >>> full_url = url + '?' + url_values + >>> data = urllib2.open(full_url) + +Notice that the full URL is created by adding a ``?`` to the URL, followed by +the encoded values. + +Headers +------- + +We'll discuss here one particular HTTP header, to illustrate how to add headers +to your HTTP request. + +Some websites [#]_ dislike being browsed by programs, or send different versions +to different browsers [#]_ . By default urllib2 identifies itself as +``Python-urllib/x.y`` (where ``x`` and ``y`` are the major and minor version +numbers of the Python release, +e.g. ``Python-urllib/2.5``), which may confuse the site, or just plain +not work. The way a browser identifies itself is through the +``User-Agent`` header [#]_. When you create a Request object you can +pass a dictionary of headers in. The following example makes the same +request as above, but identifies itself as a version of Internet +Explorer [#]_. :: + + import urllib + import urllib2 + + url = 'http://www.someserver.com/cgi-bin/register.cgi' + user_agent = 'Mozilla/4.0 (compatible; MSIE 5.5; Windows NT)' + values = {'name' : 'Michael Foord', + 'location' : 'Northampton', + 'language' : 'Python' } + headers = { 'User-Agent' : user_agent } + + data = urllib.urlencode(values) + req = urllib2.Request(url, data, headers) + response = urllib2.urlopen(req) + the_page = response.read() + +The response also has two useful methods. See the section on `info and geturl`_ +which comes after we have a look at what happens when things go wrong. + + +Handling Exceptions +=================== + +*urlopen* raises ``URLError`` when it cannot handle a response (though as usual +with Python APIs, builtin exceptions such as ValueError, TypeError etc. may also +be raised). + +``HTTPError`` is the subclass of ``URLError`` raised in the specific case of +HTTP URLs. + +URLError +-------- + +Often, URLError is raised because there is no network connection (no route to +the specified server), or the specified server doesn't exist. In this case, the +exception raised will have a 'reason' attribute, which is a tuple containing an +error code and a text error message. + +e.g. :: + + >>> req = urllib2.Request('http://www.pretend_server.org') + >>> try: urllib2.urlopen(req) + >>> except URLError, e: + >>> print e.reason + >>> + (4, 'getaddrinfo failed') + + +HTTPError +--------- + +Every HTTP response from the server contains a numeric "status code". Sometimes +the status code indicates that the server is unable to fulfil the request. The +default handlers will handle some of these responses for you (for example, if +the response is a "redirection" that requests the client fetch the document from +a different URL, urllib2 will handle that for you). For those it can't handle, +urlopen will raise an ``HTTPError``. Typical errors include '404' (page not +found), '403' (request forbidden), and '401' (authentication required). + +See section 10 of RFC 2616 for a reference on all the HTTP error codes. + +The ``HTTPError`` instance raised will have an integer 'code' attribute, which +corresponds to the error sent by the server. + +Error Codes +~~~~~~~~~~~ + +Because the default handlers handle redirects (codes in the 300 range), and +codes in the 100-299 range indicate success, you will usually only see error +codes in the 400-599 range. + +``BaseHTTPServer.BaseHTTPRequestHandler.responses`` is a useful dictionary of +response codes in that shows all the response codes used by RFC 2616. The +dictionary is reproduced here for convenience :: + + # Table mapping response codes to messages; entries have the + # form {code: (shortmessage, longmessage)}. + responses = { + 100: ('Continue', 'Request received, please continue'), + 101: ('Switching Protocols', + 'Switching to new protocol; obey Upgrade header'), + + 200: ('OK', 'Request fulfilled, document follows'), + 201: ('Created', 'Document created, URL follows'), + 202: ('Accepted', + 'Request accepted, processing continues off-line'), + 203: ('Non-Authoritative Information', 'Request fulfilled from cache'), + 204: ('No Content', 'Request fulfilled, nothing follows'), + 205: ('Reset Content', 'Clear input form for further input.'), + 206: ('Partial Content', 'Partial content follows.'), + + 300: ('Multiple Choices', + 'Object has several resources -- see URI list'), + 301: ('Moved Permanently', 'Object moved permanently -- see URI list'), + 302: ('Found', 'Object moved temporarily -- see URI list'), + 303: ('See Other', 'Object moved -- see Method and URL list'), + 304: ('Not Modified', + 'Document has not changed since given time'), + 305: ('Use Proxy', + 'You must use proxy specified in Location to access this ' + 'resource.'), + 307: ('Temporary Redirect', + 'Object moved temporarily -- see URI list'), + + 400: ('Bad Request', + 'Bad request syntax or unsupported method'), + 401: ('Unauthorized', + 'No permission -- see authorization schemes'), + 402: ('Payment Required', + 'No payment -- see charging schemes'), + 403: ('Forbidden', + 'Request forbidden -- authorization will not help'), + 404: ('Not Found', 'Nothing matches the given URI'), + 405: ('Method Not Allowed', + 'Specified method is invalid for this server.'), + 406: ('Not Acceptable', 'URI not available in preferred format.'), + 407: ('Proxy Authentication Required', 'You must authenticate with ' + 'this proxy before proceeding.'), + 408: ('Request Timeout', 'Request timed out; try again later.'), + 409: ('Conflict', 'Request conflict.'), + 410: ('Gone', + 'URI no longer exists and has been permanently removed.'), + 411: ('Length Required', 'Client must specify Content-Length.'), + 412: ('Precondition Failed', 'Precondition in headers is false.'), + 413: ('Request Entity Too Large', 'Entity is too large.'), + 414: ('Request-URI Too Long', 'URI is too long.'), + 415: ('Unsupported Media Type', 'Entity body in unsupported format.'), + 416: ('Requested Range Not Satisfiable', + 'Cannot satisfy request range.'), + 417: ('Expectation Failed', + 'Expect condition could not be satisfied.'), + + 500: ('Internal Server Error', 'Server got itself in trouble'), + 501: ('Not Implemented', + 'Server does not support this operation'), + 502: ('Bad Gateway', 'Invalid responses from another server/proxy.'), + 503: ('Service Unavailable', + 'The server cannot process the request due to a high load'), + 504: ('Gateway Timeout', + 'The gateway server did not receive a timely response'), + 505: ('HTTP Version Not Supported', 'Cannot fulfill request.'), + } + +When an error is raised the server responds by returning an HTTP error code +*and* an error page. You can use the ``HTTPError`` instance as a response on the +page returned. This means that as well as the code attribute, it also has read, +geturl, and info, methods. :: + + >>> req = urllib2.Request('http://www.python.org/fish.html') + >>> try: + >>> urllib2.urlopen(req) + >>> except URLError, e: + >>> print e.code + >>> print e.read() + >>> + 404 + + + Error 404: File Not Found + ...... etc... + +Wrapping it Up +-------------- + +So if you want to be prepared for ``HTTPError`` *or* ``URLError`` there are two +basic approaches. I prefer the second approach. + +Number 1 +~~~~~~~~ + +:: + + + from urllib2 import Request, urlopen, URLError, HTTPError + req = Request(someurl) + try: + response = urlopen(req) + except HTTPError, e: + print 'The server couldn\'t fulfill the request.' + print 'Error code: ', e.code + except URLError, e: + print 'We failed to reach a server.' + print 'Reason: ', e.reason + else: + # everything is fine + + +.. note:: + + The ``except HTTPError`` *must* come first, otherwise ``except URLError`` + will *also* catch an ``HTTPError``. + +Number 2 +~~~~~~~~ + +:: + + from urllib2 import Request, urlopen, URLError + req = Request(someurl) + try: + response = urlopen(req) + except URLError, e: + if hasattr(e, 'reason'): + print 'We failed to reach a server.' + print 'Reason: ', e.reason + elif hasattr(e, 'code'): + print 'The server couldn\'t fulfill the request.' + print 'Error code: ', e.code + else: + # everything is fine + + +info and geturl +=============== + +The response returned by urlopen (or the ``HTTPError`` instance) has two useful +methods ``info`` and ``geturl``. + +**geturl** - this returns the real URL of the page fetched. This is useful +because ``urlopen`` (or the opener object used) may have followed a +redirect. The URL of the page fetched may not be the same as the URL requested. + +**info** - this returns a dictionary-like object that describes the page +fetched, particularly the headers sent by the server. It is currently an +``httplib.HTTPMessage`` instance. + +Typical headers include 'Content-length', 'Content-type', and so on. See the +`Quick Reference to HTTP Headers `_ +for a useful listing of HTTP headers with brief explanations of their meaning +and use. + + +Openers and Handlers +==================== + +When you fetch a URL you use an opener (an instance of the perhaps +confusingly-named :class:`urllib2.OpenerDirector`). Normally we have been using +the default opener - via ``urlopen`` - but you can create custom +openers. Openers use handlers. All the "heavy lifting" is done by the +handlers. Each handler knows how to open URLs for a particular URL scheme (http, +ftp, etc.), or how to handle an aspect of URL opening, for example HTTP +redirections or HTTP cookies. + +You will want to create openers if you want to fetch URLs with specific handlers +installed, for example to get an opener that handles cookies, or to get an +opener that does not handle redirections. + +To create an opener, instantiate an ``OpenerDirector``, and then call +``.add_handler(some_handler_instance)`` repeatedly. + +Alternatively, you can use ``build_opener``, which is a convenience function for +creating opener objects with a single function call. ``build_opener`` adds +several handlers by default, but provides a quick way to add more and/or +override the default handlers. + +Other sorts of handlers you might want to can handle proxies, authentication, +and other common but slightly specialised situations. + +``install_opener`` can be used to make an ``opener`` object the (global) default +opener. This means that calls to ``urlopen`` will use the opener you have +installed. + +Opener objects have an ``open`` method, which can be called directly to fetch +urls in the same way as the ``urlopen`` function: there's no need to call +``install_opener``, except as a convenience. + + +Basic Authentication +==================== + +To illustrate creating and installing a handler we will use the +``HTTPBasicAuthHandler``. For a more detailed discussion of this subject -- +including an explanation of how Basic Authentication works - see the `Basic +Authentication Tutorial +`_. + +When authentication is required, the server sends a header (as well as the 401 +error code) requesting authentication. This specifies the authentication scheme +and a 'realm'. The header looks like : ``Www-authenticate: SCHEME +realm="REALM"``. + +e.g. :: + + Www-authenticate: Basic realm="cPanel Users" + + +The client should then retry the request with the appropriate name and password +for the realm included as a header in the request. This is 'basic +authentication'. In order to simplify this process we can create an instance of +``HTTPBasicAuthHandler`` and an opener to use this handler. + +The ``HTTPBasicAuthHandler`` uses an object called a password manager to handle +the mapping of URLs and realms to passwords and usernames. If you know what the +realm is (from the authentication header sent by the server), then you can use a +``HTTPPasswordMgr``. Frequently one doesn't care what the realm is. In that +case, it is convenient to use ``HTTPPasswordMgrWithDefaultRealm``. This allows +you to specify a default username and password for a URL. This will be supplied +in the absence of you providing an alternative combination for a specific +realm. We indicate this by providing ``None`` as the realm argument to the +``add_password`` method. + +The top-level URL is the first URL that requires authentication. URLs "deeper" +than the URL you pass to .add_password() will also match. :: + + # create a password manager + password_mgr = urllib2.HTTPPasswordMgrWithDefaultRealm() + + # Add the username and password. + # If we knew the realm, we could use it instead of ``None``. + top_level_url = "http://example.com/foo/" + password_mgr.add_password(None, top_level_url, username, password) + + handler = urllib2.HTTPBasicAuthHandler(password_mgr) + + # create "opener" (OpenerDirector instance) + opener = urllib2.build_opener(handler) + + # use the opener to fetch a URL + opener.open(a_url) + + # Install the opener. + # Now all calls to urllib2.urlopen use our opener. + urllib2.install_opener(opener) + +.. note:: + + In the above example we only supplied our ``HHTPBasicAuthHandler`` to + ``build_opener``. By default openers have the handlers for normal situations + -- ``ProxyHandler``, ``UnknownHandler``, ``HTTPHandler``, + ``HTTPDefaultErrorHandler``, ``HTTPRedirectHandler``, ``FTPHandler``, + ``FileHandler``, ``HTTPErrorProcessor``. + +``top_level_url`` is in fact *either* a full URL (including the 'http:' scheme +component and the hostname and optionally the port number) +e.g. "http://example.com/" *or* an "authority" (i.e. the hostname, +optionally including the port number) e.g. "example.com" or "example.com:8080" +(the latter example includes a port number). The authority, if present, must +NOT contain the "userinfo" component - for example "joe@password:example.com" is +not correct. + + +Proxies +======= + +**urllib2** will auto-detect your proxy settings and use those. This is through +the ``ProxyHandler`` which is part of the normal handler chain. Normally that's +a good thing, but there are occasions when it may not be helpful [#]_. One way +to do this is to setup our own ``ProxyHandler``, with no proxies defined. This +is done using similar steps to setting up a `Basic Authentication`_ handler : :: + + >>> proxy_support = urllib2.ProxyHandler({}) + >>> opener = urllib2.build_opener(proxy_support) + >>> urllib2.install_opener(opener) + +.. note:: + + Currently ``urllib2`` *does not* support fetching of ``https`` locations + through a proxy. However, this can be enabled by extending urllib2 as + shown in the recipe [#]_. + + +Sockets and Layers +================== + +The Python support for fetching resources from the web is layered. urllib2 uses +the httplib library, which in turn uses the socket library. + +As of Python 2.3 you can specify how long a socket should wait for a response +before timing out. This can be useful in applications which have to fetch web +pages. By default the socket module has *no timeout* and can hang. Currently, +the socket timeout is not exposed at the httplib or urllib2 levels. However, +you can set the default timeout globally for all sockets using :: + + import socket + import urllib2 + + # timeout in seconds + timeout = 10 + socket.setdefaulttimeout(timeout) + + # this call to urllib2.urlopen now uses the default timeout + # we have set in the socket module + req = urllib2.Request('http://www.voidspace.org.uk') + response = urllib2.urlopen(req) + + +------- + + +Footnotes +========= + +This document was reviewed and revised by John Lee. + +.. [#] For an introduction to the CGI protocol see + `Writing Web Applications in Python `_. +.. [#] Like Google for example. The *proper* way to use google from a program + is to use `PyGoogle `_ of course. See + `Voidspace Google `_ + for some examples of using the Google API. +.. [#] Browser sniffing is a very bad practise for website design - building + sites using web standards is much more sensible. Unfortunately a lot of + sites still send different versions to different browsers. +.. [#] The user agent for MSIE 6 is + *'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322)'* +.. [#] For details of more HTTP request headers, see + `Quick Reference to HTTP Headers`_. +.. [#] In my case I have to use a proxy to access the internet at work. If you + attempt to fetch *localhost* URLs through this proxy it blocks them. IE + is set to use the proxy, which urllib2 picks up on. In order to test + scripts with a localhost server, I have to prevent urllib2 from using + the proxy. +.. [#] urllib2 opener for SSL proxy (CONNECT method): `ASPN Cookbook Recipe + `_. + diff --git a/Doc/includes/email-dir.py b/Doc/includes/email-dir.py new file mode 100644 index 0000000..c04f57d --- /dev/null +++ b/Doc/includes/email-dir.py @@ -0,0 +1,115 @@ +#!/usr/bin/env python + +"""Send the contents of a directory as a MIME message.""" + +import os +import sys +import smtplib +# For guessing MIME type based on file name extension +import mimetypes + +from optparse import OptionParser + +from email import encoders +from email.message import Message +from email.mime.audio import MIMEAudio +from email.mime.base import MIMEBase +from email.mime.image import MIMEImage +from email.mime.multipart import MIMEMultipart +from email.mime.text import MIMEText + +COMMASPACE = ', ' + + +def main(): + parser = OptionParser(usage="""\ +Send the contents of a directory as a MIME message. + +Usage: %prog [options] + +Unless the -o option is given, the email is sent by forwarding to your local +SMTP server, which then does the normal delivery process. Your local machine +must be running an SMTP server. +""") + parser.add_option('-d', '--directory', + type='string', action='store', + help="""Mail the contents of the specified directory, + otherwise use the current directory. Only the regular + files in the directory are sent, and we don't recurse to + subdirectories.""") + parser.add_option('-o', '--output', + type='string', action='store', metavar='FILE', + help="""Print the composed message to FILE instead of + sending the message to the SMTP server.""") + parser.add_option('-s', '--sender', + type='string', action='store', metavar='SENDER', + help='The value of the From: header (required)') + parser.add_option('-r', '--recipient', + type='string', action='append', metavar='RECIPIENT', + default=[], dest='recipients', + help='A To: header value (at least one required)') + opts, args = parser.parse_args() + if not opts.sender or not opts.recipients: + parser.print_help() + sys.exit(1) + directory = opts.directory + if not directory: + directory = '.' + # Create the enclosing (outer) message + outer = MIMEMultipart() + outer['Subject'] = 'Contents of directory %s' % os.path.abspath(directory) + outer['To'] = COMMASPACE.join(opts.recipients) + outer['From'] = opts.sender + outer.preamble = 'You will not see this in a MIME-aware mail reader.\n' + + for filename in os.listdir(directory): + path = os.path.join(directory, filename) + if not os.path.isfile(path): + continue + # Guess the content type based on the file's extension. Encoding + # will be ignored, although we should check for simple things like + # gzip'd or compressed files. + ctype, encoding = mimetypes.guess_type(path) + if ctype is None or encoding is not None: + # No guess could be made, or the file is encoded (compressed), so + # use a generic bag-of-bits type. + ctype = 'application/octet-stream' + maintype, subtype = ctype.split('/', 1) + if maintype == 'text': + fp = open(path) + # Note: we should handle calculating the charset + msg = MIMEText(fp.read(), _subtype=subtype) + fp.close() + elif maintype == 'image': + fp = open(path, 'rb') + msg = MIMEImage(fp.read(), _subtype=subtype) + fp.close() + elif maintype == 'audio': + fp = open(path, 'rb') + msg = MIMEAudio(fp.read(), _subtype=subtype) + fp.close() + else: + fp = open(path, 'rb') + msg = MIMEBase(maintype, subtype) + msg.set_payload(fp.read()) + fp.close() + # Encode the payload using Base64 + encoders.encode_base64(msg) + # Set the filename parameter + msg.add_header('Content-Disposition', 'attachment', filename=filename) + outer.attach(msg) + # Now send or store the message + composed = outer.as_string() + if opts.output: + fp = open(opts.output, 'w') + fp.write(composed) + fp.close() + else: + s = smtplib.SMTP() + s.connect() + s.sendmail(opts.sender, opts.recipients, composed) + s.close() + + +if __name__ == '__main__': + main() diff --git a/Doc/includes/email-mime.py b/Doc/includes/email-mime.py new file mode 100644 index 0000000..5097253 --- /dev/null +++ b/Doc/includes/email-mime.py @@ -0,0 +1,32 @@ +# Import smtplib for the actual sending function +import smtplib + +# Here are the email package modules we'll need +from email.mime.image import MIMEImage +from email.mime.multipart import MIMEMultipart + +COMMASPACE = ', ' + +# Create the container (outer) email message. +msg = MIMEMultipart() +msg['Subject'] = 'Our family reunion' +# me == the sender's email address +# family = the list of all recipients' email addresses +msg['From'] = me +msg['To'] = COMMASPACE.join(family) +msg.preamble = 'Our family reunion' + +# Assume we know that the image files are all in PNG format +for file in pngfiles: + # Open the files in binary mode. Let the MIMEImage class automatically + # guess the specific image type. + fp = open(file, 'rb') + img = MIMEImage(fp.read()) + fp.close() + msg.attach(img) + +# Send the email via our own SMTP server. +s = smtplib.SMTP() +s.connect() +s.sendmail(me, family, msg.as_string()) +s.close() diff --git a/Doc/includes/email-simple.py b/Doc/includes/email-simple.py new file mode 100644 index 0000000..44152a4 --- /dev/null +++ b/Doc/includes/email-simple.py @@ -0,0 +1,25 @@ +# Import smtplib for the actual sending function +import smtplib + +# Import the email modules we'll need +from email.mime.text import MIMEText + +# Open a plain text file for reading. For this example, assume that +# the text file contains only ASCII characters. +fp = open(textfile, 'rb') +# Create a text/plain message +msg = MIMEText(fp.read()) +fp.close() + +# me == the sender's email address +# you == the recipient's email address +msg['Subject'] = 'The contents of %s' % textfile +msg['From'] = me +msg['To'] = you + +# Send the message via our own SMTP server, but don't include the +# envelope header. +s = smtplib.SMTP() +s.connect() +s.sendmail(me, [you], msg.as_string()) +s.close() diff --git a/Doc/includes/email-unpack.py b/Doc/includes/email-unpack.py new file mode 100644 index 0000000..e596b98 --- /dev/null +++ b/Doc/includes/email-unpack.py @@ -0,0 +1,68 @@ +#!/usr/bin/env python + +"""Unpack a MIME message into a directory of files.""" + +import os +import sys +import email +import errno +import mimetypes + +from optparse import OptionParser + + +def main(): + parser = OptionParser(usage="""\ +Unpack a MIME message into a directory of files. + +Usage: %prog [options] msgfile +""") + parser.add_option('-d', '--directory', + type='string', action='store', + help="""Unpack the MIME message into the named + directory, which will be created if it doesn't already + exist.""") + opts, args = parser.parse_args() + if not opts.directory: + parser.print_help() + sys.exit(1) + + try: + msgfile = args[0] + except IndexError: + parser.print_help() + sys.exit(1) + + try: + os.mkdir(opts.directory) + except OSError as e: + # Ignore directory exists error + if e.errno != errno.EEXIST: + raise + + fp = open(msgfile) + msg = email.message_from_file(fp) + fp.close() + + counter = 1 + for part in msg.walk(): + # multipart/* are just containers + if part.get_content_maintype() == 'multipart': + continue + # Applications should really sanitize the given filename so that an + # email message can't be used to overwrite important files + filename = part.get_filename() + if not filename: + ext = mimetypes.guess_extension(part.get_type()) + if not ext: + # Use a generic bag-of-bits extension + ext = '.bin' + filename = 'part-%03d%s' % (counter, ext) + counter += 1 + fp = open(os.path.join(opts.directory, filename), 'wb') + fp.write(part.get_payload(decode=True)) + fp.close() + + +if __name__ == '__main__': + main() diff --git a/Doc/includes/minidom-example.py b/Doc/includes/minidom-example.py new file mode 100644 index 0000000..c30c4e0 --- /dev/null +++ b/Doc/includes/minidom-example.py @@ -0,0 +1,64 @@ +import xml.dom.minidom + +document = """\ + +Demo slideshow +Slide title +This is a demo +Of a program for processing slides + + +Another demo slide +It is important +To have more than +one slide + + +""" + +dom = xml.dom.minidom.parseString(document) + +def getText(nodelist): + rc = "" + for node in nodelist: + if node.nodeType == node.TEXT_NODE: + rc = rc + node.data + return rc + +def handleSlideshow(slideshow): + print "" + handleSlideshowTitle(slideshow.getElementsByTagName("title")[0]) + slides = slideshow.getElementsByTagName("slide") + handleToc(slides) + handleSlides(slides) + print "" + +def handleSlides(slides): + for slide in slides: + handleSlide(slide) + +def handleSlide(slide): + handleSlideTitle(slide.getElementsByTagName("title")[0]) + handlePoints(slide.getElementsByTagName("point")) + +def handleSlideshowTitle(title): + print "%s" % getText(title.childNodes) + +def handleSlideTitle(title): + print "

%s

" % getText(title.childNodes) + +def handlePoints(points): + print "
    " + for point in points: + handlePoint(point) + print "
" + +def handlePoint(point): + print "
  • %s
    • " % getText(point.childNodes) + +def handleToc(slides): + for slide in slides: + title = slide.getElementsByTagName("title")[0] + print "

    %s

    " % getText(title.childNodes) + +handleSlideshow(dom) diff --git a/Doc/includes/noddy.c b/Doc/includes/noddy.c new file mode 100644 index 0000000..ec2d669 --- /dev/null +++ b/Doc/includes/noddy.c @@ -0,0 +1,54 @@ +#include + +typedef struct { + PyObject_HEAD + /* Type-specific fields go here. */ +} noddy_NoddyObject; + +static PyTypeObject noddy_NoddyType = { + PyObject_HEAD_INIT(NULL) + 0, /*ob_size*/ + "noddy.Noddy", /*tp_name*/ + sizeof(noddy_NoddyObject), /*tp_basicsize*/ + 0, /*tp_itemsize*/ + 0, /*tp_dealloc*/ + 0, /*tp_print*/ + 0, /*tp_getattr*/ + 0, /*tp_setattr*/ + 0, /*tp_compare*/ + 0, /*tp_repr*/ + 0, /*tp_as_number*/ + 0, /*tp_as_sequence*/ + 0, /*tp_as_mapping*/ + 0, /*tp_hash */ + 0, /*tp_call*/ + 0, /*tp_str*/ + 0, /*tp_getattro*/ + 0, /*tp_setattro*/ + 0, /*tp_as_buffer*/ + Py_TPFLAGS_DEFAULT, /*tp_flags*/ + "Noddy objects", /* tp_doc */ +}; + +static PyMethodDef noddy_methods[] = { + {NULL} /* Sentinel */ +}; + +#ifndef PyMODINIT_FUNC /* declarations for DLL import/export */ +#define PyMODINIT_FUNC void +#endif +PyMODINIT_FUNC +initnoddy(void) +{ + PyObject* m; + + noddy_NoddyType.tp_new = PyType_GenericNew; + if (PyType_Ready(&noddy_NoddyType) < 0) + return; + + m = Py_InitModule3("noddy", noddy_methods, + "Example module that creates an extension type."); + + Py_INCREF(&noddy_NoddyType); + PyModule_AddObject(m, "Noddy", (PyObject *)&noddy_NoddyType); +} diff --git a/Doc/includes/noddy2.c b/Doc/includes/noddy2.c new file mode 100644 index 0000000..2caf985 --- /dev/null +++ b/Doc/includes/noddy2.c @@ -0,0 +1,190 @@ +#include +#include "structmember.h" + +typedef struct { + PyObject_HEAD + PyObject *first; /* first name */ + PyObject *last; /* last name */ + int number; +} Noddy; + +static void +Noddy_dealloc(Noddy* self) +{ + Py_XDECREF(self->first); + Py_XDECREF(self->last); + self->ob_type->tp_free((PyObject*)self); +} + +static PyObject * +Noddy_new(PyTypeObject *type, PyObject *args, PyObject *kwds) +{ + Noddy *self; + + self = (Noddy *)type->tp_alloc(type, 0); + if (self != NULL) { + self->first = PyString_FromString(""); + if (self->first == NULL) + { + Py_DECREF(self); + return NULL; + } + + self->last = PyString_FromString(""); + if (self->last == NULL) + { + Py_DECREF(self); + return NULL; + } + + self->number = 0; + } + + return (PyObject *)self; +} + +static int +Noddy_init(Noddy *self, PyObject *args, PyObject *kwds) +{ + PyObject *first=NULL, *last=NULL, *tmp; + + static char *kwlist[] = {"first", "last", "number", NULL}; + + if (! PyArg_ParseTupleAndKeywords(args, kwds, "|OOi", kwlist, + &first, &last, + &self->number)) + return -1; + + if (first) { + tmp = self->first; + Py_INCREF(first); + self->first = first; + Py_XDECREF(tmp); + } + + if (last) { + tmp = self->last; + Py_INCREF(last); + self->last = last; + Py_XDECREF(tmp); + } + + return 0; +} + + +static PyMemberDef Noddy_members[] = { + {"first", T_OBJECT_EX, offsetof(Noddy, first), 0, + "first name"}, + {"last", T_OBJECT_EX, offsetof(Noddy, last), 0, + "last name"}, + {"number", T_INT, offsetof(Noddy, number), 0, + "noddy number"}, + {NULL} /* Sentinel */ +}; + +static PyObject * +Noddy_name(Noddy* self) +{ + static PyObject *format = NULL; + PyObject *args, *result; + + if (format == NULL) { + format = PyString_FromString("%s %s"); + if (format == NULL) + return NULL; + } + + if (self->first == NULL) { + PyErr_SetString(PyExc_AttributeError, "first"); + return NULL; + } + + if (self->last == NULL) { + PyErr_SetString(PyExc_AttributeError, "last"); + return NULL; + } + + args = Py_BuildValue("OO", self->first, self->last); + if (args == NULL) + return NULL; + + result = PyString_Format(format, args); + Py_DECREF(args); + + return result; +} + +static PyMethodDef Noddy_methods[] = { + {"name", (PyCFunction)Noddy_name, METH_NOARGS, + "Return the name, combining the first and last name" + }, + {NULL} /* Sentinel */ +}; + +static PyTypeObject NoddyType = { + PyObject_HEAD_INIT(NULL) + 0, /*ob_size*/ + "noddy.Noddy", /*tp_name*/ + sizeof(Noddy), /*tp_basicsize*/ + 0, /*tp_itemsize*/ + (destructor)Noddy_dealloc, /*tp_dealloc*/ + 0, /*tp_print*/ + 0, /*tp_getattr*/ + 0, /*tp_setattr*/ + 0, /*tp_compare*/ + 0, /*tp_repr*/ + 0, /*tp_as_number*/ + 0, /*tp_as_sequence*/ + 0, /*tp_as_mapping*/ + 0, /*tp_hash */ + 0, /*tp_call*/ + 0, /*tp_str*/ + 0, /*tp_getattro*/ + 0, /*tp_setattro*/ + 0, /*tp_as_buffer*/ + Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ + "Noddy objects", /* tp_doc */ + 0, /* tp_traverse */ + 0, /* tp_clear */ + 0, /* tp_richcompare */ + 0, /* tp_weaklistoffset */ + 0, /* tp_iter */ + 0, /* tp_iternext */ + Noddy_methods, /* tp_methods */ + Noddy_members, /* tp_members */ + 0, /* tp_getset */ + 0, /* tp_base */ + 0, /* tp_dict */ + 0, /* tp_descr_get */ + 0, /* tp_descr_set */ + 0, /* tp_dictoffset */ + (initproc)Noddy_init, /* tp_init */ + 0, /* tp_alloc */ + Noddy_new, /* tp_new */ +}; + +static PyMethodDef module_methods[] = { + {NULL} /* Sentinel */ +}; + +#ifndef PyMODINIT_FUNC /* declarations for DLL import/export */ +#define PyMODINIT_FUNC void +#endif +PyMODINIT_FUNC +initnoddy2(void) +{ + PyObject* m; + + if (PyType_Ready(&NoddyType) < 0) + return; + + m = Py_InitModule3("noddy2", module_methods, + "Example module that creates an extension type."); + + if (m == NULL) + return; + + Py_INCREF(&NoddyType); + PyModule_AddObject(m, "Noddy", (PyObject *)&NoddyType); +} diff --git a/Doc/includes/noddy3.c b/Doc/includes/noddy3.c new file mode 100644 index 0000000..60260ad --- /dev/null +++ b/Doc/includes/noddy3.c @@ -0,0 +1,243 @@ +#include +#include "structmember.h" + +typedef struct { + PyObject_HEAD + PyObject *first; + PyObject *last; + int number; +} Noddy; + +static void +Noddy_dealloc(Noddy* self) +{ + Py_XDECREF(self->first); + Py_XDECREF(self->last); + self->ob_type->tp_free((PyObject*)self); +} + +static PyObject * +Noddy_new(PyTypeObject *type, PyObject *args, PyObject *kwds) +{ + Noddy *self; + + self = (Noddy *)type->tp_alloc(type, 0); + if (self != NULL) { + self->first = PyString_FromString(""); + if (self->first == NULL) + { + Py_DECREF(self); + return NULL; + } + + self->last = PyString_FromString(""); + if (self->last == NULL) + { + Py_DECREF(self); + return NULL; + } + + self->number = 0; + } + + return (PyObject *)self; +} + +static int +Noddy_init(Noddy *self, PyObject *args, PyObject *kwds) +{ + PyObject *first=NULL, *last=NULL, *tmp; + + static char *kwlist[] = {"first", "last", "number", NULL}; + + if (! PyArg_ParseTupleAndKeywords(args, kwds, "|SSi", kwlist, + &first, &last, + &self->number)) + return -1; + + if (first) { + tmp = self->first; + Py_INCREF(first); + self->first = first; + Py_DECREF(tmp); + } + + if (last) { + tmp = self->last; + Py_INCREF(last); + self->last = last; + Py_DECREF(tmp); + } + + return 0; +} + +static PyMemberDef Noddy_members[] = { + {"number", T_INT, offsetof(Noddy, number), 0, + "noddy number"}, + {NULL} /* Sentinel */ +}; + +static PyObject * +Noddy_getfirst(Noddy *self, void *closure) +{ + Py_INCREF(self->first); + return self->first; +} + +static int +Noddy_setfirst(Noddy *self, PyObject *value, void *closure) +{ + if (value == NULL) { + PyErr_SetString(PyExc_TypeError, "Cannot delete the first attribute"); + return -1; + } + + if (! PyString_Check(value)) { + PyErr_SetString(PyExc_TypeError, + "The first attribute value must be a string"); + return -1; + } + + Py_DECREF(self->first); + Py_INCREF(value); + self->first = value; + + return 0; +} + +static PyObject * +Noddy_getlast(Noddy *self, void *closure) +{ + Py_INCREF(self->last); + return self->last; +} + +static int +Noddy_setlast(Noddy *self, PyObject *value, void *closure) +{ + if (value == NULL) { + PyErr_SetString(PyExc_TypeError, "Cannot delete the last attribute"); + return -1; + } + + if (! PyString_Check(value)) { + PyErr_SetString(PyExc_TypeError, + "The last attribute value must be a string"); + return -1; + } + + Py_DECREF(self->last); + Py_INCREF(value); + self->last = value; + + return 0; +} + +static PyGetSetDef Noddy_getseters[] = { + {"first", + (getter)Noddy_getfirst, (setter)Noddy_setfirst, + "first name", + NULL}, + {"last", + (getter)Noddy_getlast, (setter)Noddy_setlast, + "last name", + NULL}, + {NULL} /* Sentinel */ +}; + +static PyObject * +Noddy_name(Noddy* self) +{ + static PyObject *format = NULL; + PyObject *args, *result; + + if (format == NULL) { + format = PyString_FromString("%s %s"); + if (format == NULL) + return NULL; + } + + args = Py_BuildValue("OO", self->first, self->last); + if (args == NULL) + return NULL; + + result = PyString_Format(format, args); + Py_DECREF(args); + + return result; +} + +static PyMethodDef Noddy_methods[] = { + {"name", (PyCFunction)Noddy_name, METH_NOARGS, + "Return the name, combining the first and last name" + }, + {NULL} /* Sentinel */ +}; + +static PyTypeObject NoddyType = { + PyObject_HEAD_INIT(NULL) + 0, /*ob_size*/ + "noddy.Noddy", /*tp_name*/ + sizeof(Noddy), /*tp_basicsize*/ + 0, /*tp_itemsize*/ + (destructor)Noddy_dealloc, /*tp_dealloc*/ + 0, /*tp_print*/ + 0, /*tp_getattr*/ + 0, /*tp_setattr*/ + 0, /*tp_compare*/ + 0, /*tp_repr*/ + 0, /*tp_as_number*/ + 0, /*tp_as_sequence*/ + 0, /*tp_as_mapping*/ + 0, /*tp_hash */ + 0, /*tp_call*/ + 0, /*tp_str*/ + 0, /*tp_getattro*/ + 0, /*tp_setattro*/ + 0, /*tp_as_buffer*/ + Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/ + "Noddy objects", /* tp_doc */ + 0, /* tp_traverse */ + 0, /* tp_clear */ + 0, /* tp_richcompare */ + 0, /* tp_weaklistoffset */ + 0, /* tp_iter */ + 0, /* tp_iternext */ + Noddy_methods, /* tp_methods */ + Noddy_members, /* tp_members */ + Noddy_getseters, /* tp_getset */ + 0, /* tp_base */ + 0, /* tp_dict */ + 0, /* tp_descr_get */ + 0, /* tp_descr_set */ + 0, /* tp_dictoffset */ + (initproc)Noddy_init, /* tp_init */ + 0, /* tp_alloc */ + Noddy_new, /* tp_new */ +}; + +static PyMethodDef module_methods[] = { + {NULL} /* Sentinel */ +}; + +#ifndef PyMODINIT_FUNC /* declarations for DLL import/export */ +#define PyMODINIT_FUNC void +#endif +PyMODINIT_FUNC +initnoddy3(void) +{ + PyObject* m; + + if (PyType_Ready(&NoddyType) < 0) + return; + + m = Py_InitModule3("noddy3", module_methods, + "Example module that creates an extension type."); + + if (m == NULL) + return; + + Py_INCREF(&NoddyType); + PyModule_AddObject(m, "Noddy", (PyObject *)&NoddyType); +} diff --git a/Doc/includes/noddy4.c b/Doc/includes/noddy4.c new file mode 100644 index 0000000..878e086 --- /dev/null +++ b/Doc/includes/noddy4.c @@ -0,0 +1,224 @@ +#include +#include "structmember.h" + +typedef struct { + PyObject_HEAD + PyObject *first; + PyObject *last; + int number; +} Noddy; + +static int +Noddy_traverse(Noddy *self, visitproc visit, void *arg) +{ + int vret; + + if (self->first) { + vret = visit(self->first, arg); + if (vret != 0) + return vret; + } + if (self->last) { + vret = visit(self->last, arg); + if (vret != 0) + return vret; + } + + return 0; +} + +static int +Noddy_clear(Noddy *self) +{ + PyObject *tmp; + + tmp = self->first; + self->first = NULL; + Py_XDECREF(tmp); + + tmp = self->last; + self->last = NULL; + Py_XDECREF(tmp); + + return 0; +} + +static void +Noddy_dealloc(Noddy* self) +{ + Noddy_clear(self); + self->ob_type->tp_free((PyObject*)self); +} + +static PyObject * +Noddy_new(PyTypeObject *type, PyObject *args, PyObject *kwds) +{ + Noddy *self; + + self = (Noddy *)type->tp_alloc(type, 0); + if (self != NULL) { + self->first = PyString_FromString(""); + if (self->first == NULL) + { + Py_DECREF(self); + return NULL; + } + + self->last = PyString_FromString(""); + if (self->last == NULL) + { + Py_DECREF(self); + return NULL; + } + + self->number = 0; + } + + return (PyObject *)self; +} + +static int +Noddy_init(Noddy *self, PyObject *args, PyObject *kwds) +{ + PyObject *first=NULL, *last=NULL, *tmp; + + static char *kwlist[] = {"first", "last", "number", NULL}; + + if (! PyArg_ParseTupleAndKeywords(args, kwds, "|OOi", kwlist, + &first, &last, + &self->number)) + return -1; + + if (first) { + tmp = self->first; + Py_INCREF(first); + self->first = first; + Py_XDECREF(tmp); + } + + if (last) { + tmp = self->last; + Py_INCREF(last); + self->last = last; + Py_XDECREF(tmp); + } + + return 0; +} + + +static PyMemberDef Noddy_members[] = { + {"first", T_OBJECT_EX, offsetof(Noddy, first), 0, + "first name"}, + {"last", T_OBJECT_EX, offsetof(Noddy, last), 0, + "last name"}, + {"number", T_INT, offsetof(Noddy, number), 0, + "noddy number"}, + {NULL} /* Sentinel */ +}; + +static PyObject * +Noddy_name(Noddy* self) +{ + static PyObject *format = NULL; + PyObject *args, *result; + + if (format == NULL) { + format = PyString_FromString("%s %s"); + if (format == NULL) + return NULL; + } + + if (self->first == NULL) { + PyErr_SetString(PyExc_AttributeError, "first"); + return NULL; + } + + if (self->last == NULL) { + PyErr_SetString(PyExc_AttributeError, "last"); + return NULL; + } + + args = Py_BuildValue("OO", self->first, self->last); + if (args == NULL) + return NULL; + + result = PyString_Format(format, args); + Py_DECREF(args); + + return result; +} + +static PyMethodDef Noddy_methods[] = { + {"name", (PyCFunction)Noddy_name, METH_NOARGS, + "Return the name, combining the first and last name" + }, + {NULL} /* Sentinel */ +}; + +static PyTypeObject NoddyType = { + PyObject_HEAD_INIT(NULL) + 0, /*ob_size*/ + "noddy.Noddy", /*tp_name*/ + sizeof(Noddy), /*tp_basicsize*/ + 0, /*tp_itemsize*/ + (destructor)Noddy_dealloc, /*tp_dealloc*/ + 0, /*tp_print*/ + 0, /*tp_getattr*/ + 0, /*tp_setattr*/ + 0, /*tp_compare*/ + 0, /*tp_repr*/ + 0, /*tp_as_number*/ + 0, /*tp_as_sequence*/ + 0, /*tp_as_mapping*/ + 0, /*tp_hash */ + 0, /*tp_call*/ + 0, /*tp_str*/ + 0, /*tp_getattro*/ + 0, /*tp_setattro*/ + 0, /*tp_as_buffer*/ + Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE | Py_TPFLAGS_HAVE_GC, /*tp_flags*/ + "Noddy objects", /* tp_doc */ + (traverseproc)Noddy_traverse, /* tp_traverse */ + (inquiry)Noddy_clear, /* tp_clear */ + 0, /* tp_richcompare */ + 0, /* tp_weaklistoffset */ + 0, /* tp_iter */ + 0, /* tp_iternext */ + Noddy_methods, /* tp_methods */ + Noddy_members, /* tp_members */ + 0, /* tp_getset */ + 0, /* tp_base */ + 0, /* tp_dict */ + 0, /* tp_descr_get */ + 0, /* tp_descr_set */ + 0, /* tp_dictoffset */ + (initproc)Noddy_init, /* tp_init */ + 0, /* tp_alloc */ + Noddy_new, /* tp_new */ +}; + +static PyMethodDef module_methods[] = { + {NULL} /* Sentinel */ +}; + +#ifndef PyMODINIT_FUNC /* declarations for DLL import/export */ +#define PyMODINIT_FUNC void +#endif +PyMODINIT_FUNC +initnoddy4(void) +{ + PyObject* m; + + if (PyType_Ready(&NoddyType) < 0) + return; + + m = Py_InitModule3("noddy4", module_methods, + "Example module that creates an extension type."); + + if (m == NULL) + return; + + Py_INCREF(&NoddyType); + PyModule_AddObject(m, "Noddy", (PyObject *)&NoddyType); +} diff --git a/Doc/includes/run-func.c b/Doc/includes/run-func.c new file mode 100644 index 0000000..5a7df0d --- /dev/null +++ b/Doc/includes/run-func.c @@ -0,0 +1,68 @@ +#include + +int +main(int argc, char *argv[]) +{ + PyObject *pName, *pModule, *pDict, *pFunc; + PyObject *pArgs, *pValue; + int i; + + if (argc < 3) { + fprintf(stderr,"Usage: call pythonfile funcname [args]\n"); + return 1; + } + + Py_Initialize(); + pName = PyString_FromString(argv[1]); + /* Error checking of pName left out */ + + pModule = PyImport_Import(pName); + Py_DECREF(pName); + + if (pModule != NULL) { + pFunc = PyObject_GetAttrString(pModule, argv[2]); + /* pFunc is a new reference */ + + if (pFunc && PyCallable_Check(pFunc)) { + pArgs = PyTuple_New(argc - 3); + for (i = 0; i < argc - 3; ++i) { + pValue = PyInt_FromLong(atoi(argv[i + 3])); + if (!pValue) { + Py_DECREF(pArgs); + Py_DECREF(pModule); + fprintf(stderr, "Cannot convert argument\n"); + return 1; + } + /* pValue reference stolen here: */ + PyTuple_SetItem(pArgs, i, pValue); + } + pValue = PyObject_CallObject(pFunc, pArgs); + Py_DECREF(pArgs); + if (pValue != NULL) { + printf("Result of call: %ld\n", PyInt_AsLong(pValue)); + Py_DECREF(pValue); + } + else { + Py_DECREF(pFunc); + Py_DECREF(pModule); + PyErr_Print(); + fprintf(stderr,"Call failed\n"); + return 1; + } + } + else { + if (PyErr_Occurred()) + PyErr_Print(); + fprintf(stderr, "Cannot find function \"%s\"\n", argv[2]); + } + Py_XDECREF(pFunc); + Py_DECREF(pModule); + } + else { + PyErr_Print(); + fprintf(stderr, "Failed to load \"%s\"\n", argv[1]); + return 1; + } + Py_Finalize(); + return 0; +} diff --git a/Doc/includes/setup.py b/Doc/includes/setup.py new file mode 100644 index 0000000..b853d23 --- /dev/null +++ b/Doc/includes/setup.py @@ -0,0 +1,8 @@ +from distutils.core import setup, Extension +setup(name="noddy", version="1.0", + ext_modules=[ + Extension("noddy", ["noddy.c"]), + Extension("noddy2", ["noddy2.c"]), + Extension("noddy3", ["noddy3.c"]), + Extension("noddy4", ["noddy4.c"]), + ]) diff --git a/Doc/includes/shoddy.c b/Doc/includes/shoddy.c new file mode 100644 index 0000000..07a4177 --- /dev/null +++ b/Doc/includes/shoddy.c @@ -0,0 +1,91 @@ +#include + +typedef struct { + PyListObject list; + int state; +} Shoddy; + + +static PyObject * +Shoddy_increment(Shoddy *self, PyObject *unused) +{ + self->state++; + return PyInt_FromLong(self->state); +} + + +static PyMethodDef Shoddy_methods[] = { + {"increment", (PyCFunction)Shoddy_increment, METH_NOARGS, + PyDoc_STR("increment state counter")}, + {NULL, NULL}, +}; + +static int +Shoddy_init(Shoddy *self, PyObject *args, PyObject *kwds) +{ + if (PyList_Type.tp_init((PyObject *)self, args, kwds) < 0) + return -1; + self->state = 0; + return 0; +} + + +static PyTypeObject ShoddyType = { + PyObject_HEAD_INIT(NULL) + 0, /* ob_size */ + "shoddy.Shoddy", /* tp_name */ + sizeof(Shoddy), /* tp_basicsize */ + 0, /* tp_itemsize */ + 0, /* tp_dealloc */ + 0, /* tp_print */ + 0, /* tp_getattr */ + 0, /* tp_setattr */ + 0, /* tp_compare */ + 0, /* tp_repr */ + 0, /* tp_as_number */ + 0, /* tp_as_sequence */ + 0, /* tp_as_mapping */ + 0, /* tp_hash */ + 0, /* tp_call */ + 0, /* tp_str */ + 0, /* tp_getattro */ + 0, /* tp_setattro */ + 0, /* tp_as_buffer */ + Py_TPFLAGS_DEFAULT | + Py_TPFLAGS_BASETYPE, /* tp_flags */ + 0, /* tp_doc */ + 0, /* tp_traverse */ + 0, /* tp_clear */ + 0, /* tp_richcompare */ + 0, /* tp_weaklistoffset */ + 0, /* tp_iter */ + 0, /* tp_iternext */ + Shoddy_methods, /* tp_methods */ + 0, /* tp_members */ + 0, /* tp_getset */ + 0, /* tp_base */ + 0, /* tp_dict */ + 0, /* tp_descr_get */ + 0, /* tp_descr_set */ + 0, /* tp_dictoffset */ + (initproc)Shoddy_init, /* tp_init */ + 0, /* tp_alloc */ + 0, /* tp_new */ +}; + +PyMODINIT_FUNC +initshoddy(void) +{ + PyObject *m; + + ShoddyType.tp_base = &PyList_Type; + if (PyType_Ready(&ShoddyType) < 0) + return; + + m = Py_InitModule3("shoddy", NULL, "Shoddy module"); + if (m == NULL) + return; + + Py_INCREF(&ShoddyType); + PyModule_AddObject(m, "Shoddy", (PyObject *) &ShoddyType); +} diff --git a/Doc/includes/sqlite3/adapter_datetime.py b/Doc/includes/sqlite3/adapter_datetime.py new file mode 100644 index 0000000..5869e22 --- /dev/null +++ b/Doc/includes/sqlite3/adapter_datetime.py @@ -0,0 +1,14 @@ +import sqlite3 +import datetime, time + +def adapt_datetime(ts): + return time.mktime(ts.timetuple()) + +sqlite3.register_adapter(datetime.datetime, adapt_datetime) + +con = sqlite3.connect(":memory:") +cur = con.cursor() + +now = datetime.datetime.now() +cur.execute("select ?", (now,)) +print(cur.fetchone()[0]) diff --git a/Doc/includes/sqlite3/adapter_point_1.py b/Doc/includes/sqlite3/adapter_point_1.py new file mode 100644 index 0000000..1343acd --- /dev/null +++ b/Doc/includes/sqlite3/adapter_point_1.py @@ -0,0 +1,16 @@ +import sqlite3 + +class Point(object): + def __init__(self, x, y): + self.x, self.y = x, y + + def __conform__(self, protocol): + if protocol is sqlite3.PrepareProtocol: + return "%f;%f" % (self.x, self.y) + +con = sqlite3.connect(":memory:") +cur = con.cursor() + +p = Point(4.0, -3.2) +cur.execute("select ?", (p,)) +print(cur.fetchone()[0]) diff --git a/Doc/includes/sqlite3/adapter_point_2.py b/Doc/includes/sqlite3/adapter_point_2.py new file mode 100644 index 0000000..1e1719a --- /dev/null +++ b/Doc/includes/sqlite3/adapter_point_2.py @@ -0,0 +1,17 @@ +import sqlite3 + +class Point(object): + def __init__(self, x, y): + self.x, self.y = x, y + +def adapt_point(point): + return "%f;%f" % (point.x, point.y) + +sqlite3.register_adapter(Point, adapt_point) + +con = sqlite3.connect(":memory:") +cur = con.cursor() + +p = Point(4.0, -3.2) +cur.execute("select ?", (p,)) +print(cur.fetchone()[0]) diff --git a/Doc/includes/sqlite3/collation_reverse.py b/Doc/includes/sqlite3/collation_reverse.py new file mode 100644 index 0000000..bfd7f5b --- /dev/null +++ b/Doc/includes/sqlite3/collation_reverse.py @@ -0,0 +1,15 @@ +import sqlite3 + +def collate_reverse(string1, string2): + return -cmp(string1, string2) + +con = sqlite3.connect(":memory:") +con.create_collation("reverse", collate_reverse) + +cur = con.cursor() +cur.execute("create table test(x)") +cur.executemany("insert into test(x) values (?)", [("a",), ("b",)]) +cur.execute("select x from test order by x collate reverse") +for row in cur: + print(row) +con.close() diff --git a/Doc/includes/sqlite3/complete_statement.py b/Doc/includes/sqlite3/complete_statement.py new file mode 100644 index 0000000..cd38d73 --- /dev/null +++ b/Doc/includes/sqlite3/complete_statement.py @@ -0,0 +1,30 @@ +# A minimal SQLite shell for experiments + +import sqlite3 + +con = sqlite3.connect(":memory:") +con.isolation_level = None +cur = con.cursor() + +buffer = "" + +print("Enter your SQL commands to execute in sqlite3.") +print("Enter a blank line to exit.") + +while True: + line = input() + if line == "": + break + buffer += line + if sqlite3.complete_statement(buffer): + try: + buffer = buffer.strip() + cur.execute(buffer) + + if buffer.lstrip().upper().startswith("SELECT"): + print(cur.fetchall()) + except sqlite3.Error as e: + print("An error occurred:", e.args[0]) + buffer = "" + +con.close() diff --git a/Doc/includes/sqlite3/connect_db_1.py b/Doc/includes/sqlite3/connect_db_1.py new file mode 100644 index 0000000..1b97523 --- /dev/null +++ b/Doc/includes/sqlite3/connect_db_1.py @@ -0,0 +1,3 @@ +import sqlite3 + +con = sqlite3.connect("mydb") diff --git a/Doc/includes/sqlite3/connect_db_2.py b/Doc/includes/sqlite3/connect_db_2.py new file mode 100644 index 0000000..f9728b36 --- /dev/null +++ b/Doc/includes/sqlite3/connect_db_2.py @@ -0,0 +1,3 @@ +import sqlite3 + +con = sqlite3.connect(":memory:") diff --git a/Doc/includes/sqlite3/converter_point.py b/Doc/includes/sqlite3/converter_point.py new file mode 100644 index 0000000..d0707ab --- /dev/null +++ b/Doc/includes/sqlite3/converter_point.py @@ -0,0 +1,47 @@ +import sqlite3 + +class Point(object): + def __init__(self, x, y): + self.x, self.y = x, y + + def __repr__(self): + return "(%f;%f)" % (self.x, self.y) + +def adapt_point(point): + return "%f;%f" % (point.x, point.y) + +def convert_point(s): + x, y = list(map(float, s.split(";"))) + return Point(x, y) + +# Register the adapter +sqlite3.register_adapter(Point, adapt_point) + +# Register the converter +sqlite3.register_converter("point", convert_point) + +p = Point(4.0, -3.2) + +######################### +# 1) Using declared types +con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES) +cur = con.cursor() +cur.execute("create table test(p point)") + +cur.execute("insert into test(p) values (?)", (p,)) +cur.execute("select p from test") +print("with declared types:", cur.fetchone()[0]) +cur.close() +con.close() + +####################### +# 1) Using column names +con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_COLNAMES) +cur = con.cursor() +cur.execute("create table test(p)") + +cur.execute("insert into test(p) values (?)", (p,)) +cur.execute('select p as "p [point]" from test') +print("with column names:", cur.fetchone()[0]) +cur.close() +con.close() diff --git a/Doc/includes/sqlite3/countcursors.py b/Doc/includes/sqlite3/countcursors.py new file mode 100644 index 0000000..ef3e70a --- /dev/null +++ b/Doc/includes/sqlite3/countcursors.py @@ -0,0 +1,15 @@ +import sqlite3 + +class CountCursorsConnection(sqlite3.Connection): + def __init__(self, *args, **kwargs): + sqlite3.Connection.__init__(self, *args, **kwargs) + self.numcursors = 0 + + def cursor(self, *args, **kwargs): + self.numcursors += 1 + return sqlite3.Connection.cursor(self, *args, **kwargs) + +con = sqlite3.connect(":memory:", factory=CountCursorsConnection) +cur1 = con.cursor() +cur2 = con.cursor() +print(con.numcursors) diff --git a/Doc/includes/sqlite3/createdb.py b/Doc/includes/sqlite3/createdb.py new file mode 100644 index 0000000..ee2950b --- /dev/null +++ b/Doc/includes/sqlite3/createdb.py @@ -0,0 +1,28 @@ +# Not referenced from the documentation, but builds the database file the other +# code snippets expect. + +import sqlite3 +import os + +DB_FILE = "mydb" + +if os.path.exists(DB_FILE): + os.remove(DB_FILE) + +con = sqlite3.connect(DB_FILE) +cur = con.cursor() +cur.execute(""" + create table people + ( + name_last varchar(20), + age integer + ) + """) + +cur.execute("insert into people (name_last, age) values ('Yeltsin', 72)") +cur.execute("insert into people (name_last, age) values ('Putin', 51)") + +con.commit() + +cur.close() +con.close() diff --git a/Doc/includes/sqlite3/execsql_fetchonerow.py b/Doc/includes/sqlite3/execsql_fetchonerow.py new file mode 100644 index 0000000..078873b --- /dev/null +++ b/Doc/includes/sqlite3/execsql_fetchonerow.py @@ -0,0 +1,17 @@ +import sqlite3 + +con = sqlite3.connect("mydb") + +cur = con.cursor() +SELECT = "select name_last, age from people order by age, name_last" + +# 1. Iterate over the rows available from the cursor, unpacking the +# resulting sequences to yield their elements (name_last, age): +cur.execute(SELECT) +for (name_last, age) in cur: + print('%s is %d years old.' % (name_last, age)) + +# 2. Equivalently: +cur.execute(SELECT) +for row in cur: + print('%s is %d years old.' % (row[0], row[1])) diff --git a/Doc/includes/sqlite3/execsql_printall_1.py b/Doc/includes/sqlite3/execsql_printall_1.py new file mode 100644 index 0000000..a4ce5c5 --- /dev/null +++ b/Doc/includes/sqlite3/execsql_printall_1.py @@ -0,0 +1,13 @@ +import sqlite3 + +# Create a connection to the database file "mydb": +con = sqlite3.connect("mydb") + +# Get a Cursor object that operates in the context of Connection con: +cur = con.cursor() + +# Execute the SELECT statement: +cur.execute("select * from people order by age") + +# Retrieve all rows as a sequence and print that sequence: +print(cur.fetchall()) diff --git a/Doc/includes/sqlite3/execute_1.py b/Doc/includes/sqlite3/execute_1.py new file mode 100644 index 0000000..3d08840 --- /dev/null +++ b/Doc/includes/sqlite3/execute_1.py @@ -0,0 +1,11 @@ +import sqlite3 + +con = sqlite3.connect("mydb") + +cur = con.cursor() + +who = "Yeltsin" +age = 72 + +cur.execute("select name_last, age from people where name_last=? and age=?", (who, age)) +print(cur.fetchone()) diff --git a/Doc/includes/sqlite3/execute_2.py b/Doc/includes/sqlite3/execute_2.py new file mode 100644 index 0000000..84734f9 --- /dev/null +++ b/Doc/includes/sqlite3/execute_2.py @@ -0,0 +1,12 @@ +import sqlite3 + +con = sqlite3.connect("mydb") + +cur = con.cursor() + +who = "Yeltsin" +age = 72 + +cur.execute("select name_last, age from people where name_last=:who and age=:age", + {"who": who, "age": age}) +print(cur.fetchone()) diff --git a/Doc/includes/sqlite3/execute_3.py b/Doc/includes/sqlite3/execute_3.py new file mode 100644 index 0000000..0353683 --- /dev/null +++ b/Doc/includes/sqlite3/execute_3.py @@ -0,0 +1,12 @@ +import sqlite3 + +con = sqlite3.connect("mydb") + +cur = con.cursor() + +who = "Yeltsin" +age = 72 + +cur.execute("select name_last, age from people where name_last=:who and age=:age", + locals()) +print(cur.fetchone()) diff --git a/Doc/includes/sqlite3/executemany_1.py b/Doc/includes/sqlite3/executemany_1.py new file mode 100644 index 0000000..efae106 --- /dev/null +++ b/Doc/includes/sqlite3/executemany_1.py @@ -0,0 +1,24 @@ +import sqlite3 + +class IterChars: + def __init__(self): + self.count = ord('a') + + def __iter__(self): + return self + + def __next__(self): + if self.count > ord('z'): + raise StopIteration + self.count += 1 + return (chr(self.count - 1),) # this is a 1-tuple + +con = sqlite3.connect(":memory:") +cur = con.cursor() +cur.execute("create table characters(c)") + +theIter = IterChars() +cur.executemany("insert into characters(c) values (?)", theIter) + +cur.execute("select c from characters") +print(cur.fetchall()) diff --git a/Doc/includes/sqlite3/executemany_2.py b/Doc/includes/sqlite3/executemany_2.py new file mode 100644 index 0000000..518cd94 --- /dev/null +++ b/Doc/includes/sqlite3/executemany_2.py @@ -0,0 +1,15 @@ +import sqlite3 + +def char_generator(): + import string + for c in string.letters[:26]: + yield (c,) + +con = sqlite3.connect(":memory:") +cur = con.cursor() +cur.execute("create table characters(c)") + +cur.executemany("insert into characters(c) values (?)", char_generator()) + +cur.execute("select c from characters") +print(cur.fetchall()) diff --git a/Doc/includes/sqlite3/executescript.py b/Doc/includes/sqlite3/executescript.py new file mode 100644 index 0000000..7e53581 --- /dev/null +++ b/Doc/includes/sqlite3/executescript.py @@ -0,0 +1,24 @@ +import sqlite3 + +con = sqlite3.connect(":memory:") +cur = con.cursor() +cur.executescript(""" + create table person( + firstname, + lastname, + age + ); + + create table book( + title, + author, + published + ); + + insert into book(title, author, published) + values ( + 'Dirk Gently''s Holistic Detective Agency', + 'Douglas Adams', + 1987 + ); + """) diff --git a/Doc/includes/sqlite3/insert_more_people.py b/Doc/includes/sqlite3/insert_more_people.py new file mode 100644 index 0000000..edbc79e --- /dev/null +++ b/Doc/includes/sqlite3/insert_more_people.py @@ -0,0 +1,16 @@ +import sqlite3 + +con = sqlite3.connect("mydb") + +cur = con.cursor() + +newPeople = ( + ('Lebed' , 53), + ('Zhirinovsky' , 57), + ) + +for person in newPeople: + cur.execute("insert into people (name_last, age) values (?, ?)", person) + +# The changes will not be saved unless the transaction is committed explicitly: +con.commit() diff --git a/Doc/includes/sqlite3/md5func.py b/Doc/includes/sqlite3/md5func.py new file mode 100644 index 0000000..b7bc05b --- /dev/null +++ b/Doc/includes/sqlite3/md5func.py @@ -0,0 +1,11 @@ +import sqlite3 +import hashlib + +def md5sum(t): + return hashlib.md5(t).hexdigest() + +con = sqlite3.connect(":memory:") +con.create_function("md5", 1, md5sum) +cur = con.cursor() +cur.execute("select md5(?)", ("foo",)) +print(cur.fetchone()[0]) diff --git a/Doc/includes/sqlite3/mysumaggr.py b/Doc/includes/sqlite3/mysumaggr.py new file mode 100644 index 0000000..d2dfd2c --- /dev/null +++ b/Doc/includes/sqlite3/mysumaggr.py @@ -0,0 +1,20 @@ +import sqlite3 + +class MySum: + def __init__(self): + self.count = 0 + + def step(self, value): + self.count += value + + def finalize(self): + return self.count + +con = sqlite3.connect(":memory:") +con.create_aggregate("mysum", 1, MySum) +cur = con.cursor() +cur.execute("create table test(i)") +cur.execute("insert into test(i) values (1)") +cur.execute("insert into test(i) values (2)") +cur.execute("select mysum(i) from test") +print(cur.fetchone()[0]) diff --git a/Doc/includes/sqlite3/parse_colnames.py b/Doc/includes/sqlite3/parse_colnames.py new file mode 100644 index 0000000..cc68c76 --- /dev/null +++ b/Doc/includes/sqlite3/parse_colnames.py @@ -0,0 +1,8 @@ +import sqlite3 +import datetime + +con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_COLNAMES) +cur = con.cursor() +cur.execute('select ? as "x [timestamp]"', (datetime.datetime.now(),)) +dt = cur.fetchone()[0] +print(dt, type(dt)) diff --git a/Doc/includes/sqlite3/pysqlite_datetime.py b/Doc/includes/sqlite3/pysqlite_datetime.py new file mode 100644 index 0000000..68d4935 --- /dev/null +++ b/Doc/includes/sqlite3/pysqlite_datetime.py @@ -0,0 +1,20 @@ +import sqlite3 +import datetime + +con = sqlite3.connect(":memory:", detect_types=sqlite3.PARSE_DECLTYPES|sqlite3.PARSE_COLNAMES) +cur = con.cursor() +cur.execute("create table test(d date, ts timestamp)") + +today = datetime.date.today() +now = datetime.datetime.now() + +cur.execute("insert into test(d, ts) values (?, ?)", (today, now)) +cur.execute("select d, ts from test") +row = cur.fetchone() +print(today, "=>", row[0], type(row[0])) +print(now, "=>", row[1], type(row[1])) + +cur.execute('select current_date as "d [date]", current_timestamp as "ts [timestamp]"') +row = cur.fetchone() +print("current_date", row[0], type(row[0])) +print("current_timestamp", row[1], type(row[1])) diff --git a/Doc/includes/sqlite3/row_factory.py b/Doc/includes/sqlite3/row_factory.py new file mode 100644 index 0000000..e436ffc --- /dev/null +++ b/Doc/includes/sqlite3/row_factory.py @@ -0,0 +1,13 @@ +import sqlite3 + +def dict_factory(cursor, row): + d = {} + for idx, col in enumerate(cursor.description): + d[col[0]] = row[idx] + return d + +con = sqlite3.connect(":memory:") +con.row_factory = dict_factory +cur = con.cursor() +cur.execute("select 1 as a") +print(cur.fetchone()["a"]) diff --git a/Doc/includes/sqlite3/rowclass.py b/Doc/includes/sqlite3/rowclass.py new file mode 100644 index 0000000..3fa0b87 --- /dev/null +++ b/Doc/includes/sqlite3/rowclass.py @@ -0,0 +1,12 @@ +import sqlite3 + +con = sqlite3.connect("mydb") +con.row_factory = sqlite3.Row + +cur = con.cursor() +cur.execute("select name_last, age from people") +for row in cur: + assert row[0] == row["name_last"] + assert row["name_last"] == row["nAmE_lAsT"] + assert row[1] == row["age"] + assert row[1] == row["AgE"] diff --git a/Doc/includes/sqlite3/shared_cache.py b/Doc/includes/sqlite3/shared_cache.py new file mode 100644 index 0000000..bf1d7b4 --- /dev/null +++ b/Doc/includes/sqlite3/shared_cache.py @@ -0,0 +1,6 @@ +import sqlite3 + +# The shared cache is only available in SQLite versions 3.3.3 or later +# See the SQLite documentaton for details. + +sqlite3.enable_shared_cache(True) diff --git a/Doc/includes/sqlite3/shortcut_methods.py b/Doc/includes/sqlite3/shortcut_methods.py new file mode 100644 index 0000000..596d87c --- /dev/null +++ b/Doc/includes/sqlite3/shortcut_methods.py @@ -0,0 +1,21 @@ +import sqlite3 + +persons = [ + ("Hugo", "Boss"), + ("Calvin", "Klein") + ] + +con = sqlite3.connect(":memory:") + +# Create the table +con.execute("create table person(firstname, lastname)") + +# Fill the table +con.executemany("insert into person(firstname, lastname) values (?, ?)", persons) + +# Print the table contents +for row in con.execute("select firstname, lastname from person"): + print(row) + +# Using a dummy WHERE clause to not let SQLite take the shortcut table deletes. +print("I just deleted", con.execute("delete from person where 1=1").rowcount, "rows") diff --git a/Doc/includes/sqlite3/simple_tableprinter.py b/Doc/includes/sqlite3/simple_tableprinter.py new file mode 100644 index 0000000..231d872 --- /dev/null +++ b/Doc/includes/sqlite3/simple_tableprinter.py @@ -0,0 +1,26 @@ +import sqlite3 + +FIELD_MAX_WIDTH = 20 +TABLE_NAME = 'people' +SELECT = 'select * from %s order by age, name_last' % TABLE_NAME + +con = sqlite3.connect("mydb") + +cur = con.cursor() +cur.execute(SELECT) + +# Print a header. +for fieldDesc in cur.description: + print(fieldDesc[0].ljust(FIELD_MAX_WIDTH), end=' ') +print() # Finish the header with a newline. +print('-' * 78) + +# For each row, print the value of each field left-justified within +# the maximum possible width of that field. +fieldIndices = range(len(cur.description)) +for row in cur: + for fieldIndex in fieldIndices: + fieldValue = str(row[fieldIndex]) + print(fieldValue.ljust(FIELD_MAX_WIDTH), end=' ') + + print() # Finish the row with a newline. diff --git a/Doc/includes/sqlite3/text_factory.py b/Doc/includes/sqlite3/text_factory.py new file mode 100644 index 0000000..2dab8e4 --- /dev/null +++ b/Doc/includes/sqlite3/text_factory.py @@ -0,0 +1,42 @@ +import sqlite3 + +con = sqlite3.connect(":memory:") +cur = con.cursor() + +# Create the table +con.execute("create table person(lastname, firstname)") + +AUSTRIA = "\xd6sterreich" + +# by default, rows are returned as Unicode +cur.execute("select ?", (AUSTRIA,)) +row = cur.fetchone() +assert row[0] == AUSTRIA + +# but we can make pysqlite always return bytestrings ... +con.text_factory = str +cur.execute("select ?", (AUSTRIA,)) +row = cur.fetchone() +assert type(row[0]) == str +# the bytestrings will be encoded in UTF-8, unless you stored garbage in the +# database ... +assert row[0] == AUSTRIA.encode("utf-8") + +# we can also implement a custom text_factory ... +# here we implement one that will ignore Unicode characters that cannot be +# decoded from UTF-8 +con.text_factory = lambda x: str(x, "utf-8", "ignore") +cur.execute("select ?", ("this is latin1 and would normally create errors" + "\xe4\xf6\xfc".encode("latin1"),)) +row = cur.fetchone() +assert type(row[0]) == str + +# pysqlite offers a builtin optimized text_factory that will return bytestring +# objects, if the data is in ASCII only, and otherwise return unicode objects +con.text_factory = sqlite3.OptimizedUnicode +cur.execute("select ?", (AUSTRIA,)) +row = cur.fetchone() +assert type(row[0]) == str + +cur.execute("select ?", ("Germany",)) +row = cur.fetchone() +assert type(row[0]) == str diff --git a/Doc/includes/test.py b/Doc/includes/test.py new file mode 100644 index 0000000..7ebf46a --- /dev/null +++ b/Doc/includes/test.py @@ -0,0 +1,213 @@ +"""Test module for the noddy examples + +Noddy 1: + +>>> import noddy +>>> n1 = noddy.Noddy() +>>> n2 = noddy.Noddy() +>>> del n1 +>>> del n2 + + +Noddy 2 + +>>> import noddy2 +>>> n1 = noddy2.Noddy('jim', 'fulton', 42) +>>> n1.first +'jim' +>>> n1.last +'fulton' +>>> n1.number +42 +>>> n1.name() +'jim fulton' +>>> n1.first = 'will' +>>> n1.name() +'will fulton' +>>> n1.last = 'tell' +>>> n1.name() +'will tell' +>>> del n1.first +>>> n1.name() +Traceback (most recent call last): +... +AttributeError: first +>>> n1.first +Traceback (most recent call last): +... +AttributeError: first +>>> n1.first = 'drew' +>>> n1.first +'drew' +>>> del n1.number +Traceback (most recent call last): +... +TypeError: can't delete numeric/char attribute +>>> n1.number=2 +>>> n1.number +2 +>>> n1.first = 42 +>>> n1.name() +'42 tell' +>>> n2 = noddy2.Noddy() +>>> n2.name() +' ' +>>> n2.first +'' +>>> n2.last +'' +>>> del n2.first +>>> n2.first +Traceback (most recent call last): +... +AttributeError: first +>>> n2.first +Traceback (most recent call last): +... +AttributeError: first +>>> n2.name() +Traceback (most recent call last): + File "", line 1, in ? +AttributeError: first +>>> n2.number +0 +>>> n3 = noddy2.Noddy('jim', 'fulton', 'waaa') +Traceback (most recent call last): + File "", line 1, in ? +TypeError: an integer is required +>>> del n1 +>>> del n2 + + +Noddy 3 + +>>> import noddy3 +>>> n1 = noddy3.Noddy('jim', 'fulton', 42) +>>> n1 = noddy3.Noddy('jim', 'fulton', 42) +>>> n1.name() +'jim fulton' +>>> del n1.first +Traceback (most recent call last): + File "", line 1, in ? +TypeError: Cannot delete the first attribute +>>> n1.first = 42 +Traceback (most recent call last): + File "", line 1, in ? +TypeError: The first attribute value must be a string +>>> n1.first = 'will' +>>> n1.name() +'will fulton' +>>> n2 = noddy3.Noddy() +>>> n2 = noddy3.Noddy() +>>> n2 = noddy3.Noddy() +>>> n3 = noddy3.Noddy('jim', 'fulton', 'waaa') +Traceback (most recent call last): + File "", line 1, in ? +TypeError: an integer is required +>>> del n1 +>>> del n2 + +Noddy 4 + +>>> import noddy4 +>>> n1 = noddy4.Noddy('jim', 'fulton', 42) +>>> n1.first +'jim' +>>> n1.last +'fulton' +>>> n1.number +42 +>>> n1.name() +'jim fulton' +>>> n1.first = 'will' +>>> n1.name() +'will fulton' +>>> n1.last = 'tell' +>>> n1.name() +'will tell' +>>> del n1.first +>>> n1.name() +Traceback (most recent call last): +... +AttributeError: first +>>> n1.first +Traceback (most recent call last): +... +AttributeError: first +>>> n1.first = 'drew' +>>> n1.first +'drew' +>>> del n1.number +Traceback (most recent call last): +... +TypeError: can't delete numeric/char attribute +>>> n1.number=2 +>>> n1.number +2 +>>> n1.first = 42 +>>> n1.name() +'42 tell' +>>> n2 = noddy4.Noddy() +>>> n2 = noddy4.Noddy() +>>> n2 = noddy4.Noddy() +>>> n2 = noddy4.Noddy() +>>> n2.name() +' ' +>>> n2.first +'' +>>> n2.last +'' +>>> del n2.first +>>> n2.first +Traceback (most recent call last): +... +AttributeError: first +>>> n2.first +Traceback (most recent call last): +... +AttributeError: first +>>> n2.name() +Traceback (most recent call last): + File "", line 1, in ? +AttributeError: first +>>> n2.number +0 +>>> n3 = noddy4.Noddy('jim', 'fulton', 'waaa') +Traceback (most recent call last): + File "", line 1, in ? +TypeError: an integer is required + + +Test cyclic gc(?) + +>>> import gc +>>> gc.disable() + +>>> x = [] +>>> l = [x] +>>> n2.first = l +>>> n2.first +[[]] +>>> l.append(n2) +>>> del l +>>> del n1 +>>> del n2 +>>> sys.getrefcount(x) +3 +>>> ignore = gc.collect() +>>> sys.getrefcount(x) +2 + +>>> gc.enable() +""" + +import os +import sys +from distutils.util import get_platform +PLAT_SPEC = "%s-%s" % (get_platform(), sys.version[0:3]) +src = os.path.join("build", "lib.%s" % PLAT_SPEC) +sys.path.append(src) + +if __name__ == "__main__": + import doctest, __main__ + doctest.testmod(__main__) diff --git a/Doc/includes/typestruct.h b/Doc/includes/typestruct.h new file mode 100644 index 0000000..0afe375 --- /dev/null +++ b/Doc/includes/typestruct.h @@ -0,0 +1,76 @@ +typedef struct _typeobject { + PyObject_VAR_HEAD + char *tp_name; /* For printing, in format "." */ + int tp_basicsize, tp_itemsize; /* For allocation */ + + /* Methods to implement standard operations */ + + destructor tp_dealloc; + printfunc tp_print; + getattrfunc tp_getattr; + setattrfunc tp_setattr; + cmpfunc tp_compare; + reprfunc tp_repr; + + /* Method suites for standard classes */ + + PyNumberMethods *tp_as_number; + PySequenceMethods *tp_as_sequence; + PyMappingMethods *tp_as_mapping; + + /* More standard operations (here for binary compatibility) */ + + hashfunc tp_hash; + ternaryfunc tp_call; + reprfunc tp_str; + getattrofunc tp_getattro; + setattrofunc tp_setattro; + + /* Functions to access object as input/output buffer */ + PyBufferProcs *tp_as_buffer; + + /* Flags to define presence of optional/expanded features */ + long tp_flags; + + char *tp_doc; /* Documentation string */ + + /* Assigned meaning in release 2.0 */ + /* call function for all accessible objects */ + traverseproc tp_traverse; + + /* delete references to contained objects */ + inquiry tp_clear; + + /* Assigned meaning in release 2.1 */ + /* rich comparisons */ + richcmpfunc tp_richcompare; + + /* weak reference enabler */ + long tp_weaklistoffset; + + /* Added in release 2.2 */ + /* Iterators */ + getiterfunc tp_iter; + iternextfunc tp_iternext; + + /* Attribute descriptor and subclassing stuff */ + struct PyMethodDef *tp_methods; + struct PyMemberDef *tp_members; + struct PyGetSetDef *tp_getset; + struct _typeobject *tp_base; + PyObject *tp_dict; + descrgetfunc tp_descr_get; + descrsetfunc tp_descr_set; + long tp_dictoffset; + initproc tp_init; + allocfunc tp_alloc; + newfunc tp_new; + freefunc tp_free; /* Low-level free-memory routine */ + inquiry tp_is_gc; /* For PyObject_IS_GC */ + PyObject *tp_bases; + PyObject *tp_mro; /* method resolution order */ + PyObject *tp_cache; + PyObject *tp_subclasses; + PyObject *tp_weaklist; + +} PyTypeObject; diff --git a/Doc/includes/tzinfo-examples.py b/Doc/includes/tzinfo-examples.py new file mode 100644 index 0000000..5a2b8ad --- /dev/null +++ b/Doc/includes/tzinfo-examples.py @@ -0,0 +1,139 @@ +from datetime import tzinfo, timedelta, datetime + +ZERO = timedelta(0) +HOUR = timedelta(hours=1) + +# A UTC class. + +class UTC(tzinfo): + """UTC""" + + def utcoffset(self, dt): + return ZERO + + def tzname(self, dt): + return "UTC" + + def dst(self, dt): + return ZERO + +utc = UTC() + +# A class building tzinfo objects for fixed-offset time zones. +# Note that FixedOffset(0, "UTC") is a different way to build a +# UTC tzinfo object. + +class FixedOffset(tzinfo): + """Fixed offset in minutes east from UTC.""" + + def __init__(self, offset, name): + self.__offset = timedelta(minutes = offset) + self.__name = name + + def utcoffset(self, dt): + return self.__offset + + def tzname(self, dt): + return self.__name + + def dst(self, dt): + return ZERO + +# A class capturing the platform's idea of local time. + +import time as _time + +STDOFFSET = timedelta(seconds = -_time.timezone) +if _time.daylight: + DSTOFFSET = timedelta(seconds = -_time.altzone) +else: + DSTOFFSET = STDOFFSET + +DSTDIFF = DSTOFFSET - STDOFFSET + +class LocalTimezone(tzinfo): + + def utcoffset(self, dt): + if self._isdst(dt): + return DSTOFFSET + else: + return STDOFFSET + + def dst(self, dt): + if self._isdst(dt): + return DSTDIFF + else: + return ZERO + + def tzname(self, dt): + return _time.tzname[self._isdst(dt)] + + def _isdst(self, dt): + tt = (dt.year, dt.month, dt.day, + dt.hour, dt.minute, dt.second, + dt.weekday(), 0, -1) + stamp = _time.mktime(tt) + tt = _time.localtime(stamp) + return tt.tm_isdst > 0 + +Local = LocalTimezone() + + +# A complete implementation of current DST rules for major US time zones. + +def first_sunday_on_or_after(dt): + days_to_go = 6 - dt.weekday() + if days_to_go: + dt += timedelta(days_to_go) + return dt + +# In the US, DST starts at 2am (standard time) on the first Sunday in April. +DSTSTART = datetime(1, 4, 1, 2) +# and ends at 2am (DST time; 1am standard time) on the last Sunday of Oct. +# which is the first Sunday on or after Oct 25. +DSTEND = datetime(1, 10, 25, 1) + +class USTimeZone(tzinfo): + + def __init__(self, hours, reprname, stdname, dstname): + self.stdoffset = timedelta(hours=hours) + self.reprname = reprname + self.stdname = stdname + self.dstname = dstname + + def __repr__(self): + return self.reprname + + def tzname(self, dt): + if self.dst(dt): + return self.dstname + else: + return self.stdname + + def utcoffset(self, dt): + return self.stdoffset + self.dst(dt) + + def dst(self, dt): + if dt is None or dt.tzinfo is None: + # An exception may be sensible here, in one or both cases. + # It depends on how you want to treat them. The default + # fromutc() implementation (called by the default astimezone() + # implementation) passes a datetime with dt.tzinfo is self. + return ZERO + assert dt.tzinfo is self + + # Find first Sunday in April & the last in October. + start = first_sunday_on_or_after(DSTSTART.replace(year=dt.year)) + end = first_sunday_on_or_after(DSTEND.replace(year=dt.year)) + + # Can't compare naive to aware objects, so strip the timezone from + # dt first. + if start <= dt.replace(tzinfo=None) < end: + return HOUR + else: + return ZERO + +Eastern = USTimeZone(-5, "Eastern", "EST", "EDT") +Central = USTimeZone(-6, "Central", "CST", "CDT") +Mountain = USTimeZone(-7, "Mountain", "MST", "MDT") +Pacific = USTimeZone(-8, "Pacific", "PST", "PDT") diff --git a/Doc/install/index.rst b/Doc/install/index.rst new file mode 100644 index 0000000..01f17f8 --- /dev/null +++ b/Doc/install/index.rst @@ -0,0 +1,1011 @@ +.. highlightlang:: none + +.. _install-index: + +***************************** + Installing Python Modules +***************************** + +:Author: Greg Ward +:Release: |version| +:Date: |today| + +.. % TODO: +.. % Fill in XXX comments + +.. % The audience for this document includes people who don't know anything +.. % about Python and aren't about to learn the language just in order to +.. % install and maintain it for their users, i.e. system administrators. +.. % Thus, I have to be sure to explain the basics at some point: +.. % sys.path and PYTHONPATH at least. Should probably give pointers to +.. % other docs on "import site", PYTHONSTARTUP, PYTHONHOME, etc. +.. % +.. % Finally, it might be useful to include all the material from my "Care +.. % and Feeding of a Python Installation" talk in here somewhere. Yow! + +.. topic:: Abstract + + This document describes the Python Distribution Utilities ("Distutils") from the + end-user's point-of-view, describing how to extend the capabilities of a + standard Python installation by building and installing third-party Python + modules and extensions. + + +.. _inst-intro: + +Introduction +============ + +Although Python's extensive standard library covers many programming needs, +there often comes a time when you need to add some new functionality to your +Python installation in the form of third-party modules. This might be necessary +to support your own programming, or to support an application that you want to +use and that happens to be written in Python. + +In the past, there has been little support for adding third-party modules to an +existing Python installation. With the introduction of the Python Distribution +Utilities (Distutils for short) in Python 2.0, this changed. + +This document is aimed primarily at the people who need to install third-party +Python modules: end-users and system administrators who just need to get some +Python application running, and existing Python programmers who want to add some +new goodies to their toolbox. You don't need to know Python to read this +document; there will be some brief forays into using Python's interactive mode +to explore your installation, but that's it. If you're looking for information +on how to distribute your own Python modules so that others may use them, see +the :ref:`distutils-index` manual. + + +.. _inst-trivial-install: + +Best case: trivial installation +------------------------------- + +In the best case, someone will have prepared a special version of the module +distribution you want to install that is targeted specifically at your platform +and is installed just like any other software on your platform. For example, +the module developer might make an executable installer available for Windows +users, an RPM package for users of RPM-based Linux systems (Red Hat, SuSE, +Mandrake, and many others), a Debian package for users of Debian-based Linux +systems, and so forth. + +In that case, you would download the installer appropriate to your platform and +do the obvious thing with it: run it if it's an executable installer, ``rpm +--install`` it if it's an RPM, etc. You don't need to run Python or a setup +script, you don't need to compile anything---you might not even need to read any +instructions (although it's always a good idea to do so anyways). + +Of course, things will not always be that easy. You might be interested in a +module distribution that doesn't have an easy-to-use installer for your +platform. In that case, you'll have to start with the source distribution +released by the module's author/maintainer. Installing from a source +distribution is not too hard, as long as the modules are packaged in the +standard way. The bulk of this document is about building and installing +modules from standard source distributions. + + +.. _inst-new-standard: + +The new standard: Distutils +--------------------------- + +If you download a module source distribution, you can tell pretty quickly if it +was packaged and distributed in the standard way, i.e. using the Distutils. +First, the distribution's name and version number will be featured prominently +in the name of the downloaded archive, e.g. :file:`foo-1.0.tar.gz` or +:file:`widget-0.9.7.zip`. Next, the archive will unpack into a similarly-named +directory: :file:`foo-1.0` or :file:`widget-0.9.7`. Additionally, the +distribution will contain a setup script :file:`setup.py`, and a file named +:file:`README.txt` or possibly just :file:`README`, which should explain that +building and installing the module distribution is a simple matter of running :: + + python setup.py install + +If all these things are true, then you already know how to build and install the +modules you've just downloaded: Run the command above. Unless you need to +install things in a non-standard way or customize the build process, you don't +really need this manual. Or rather, the above command is everything you need to +get out of this manual. + + +.. _inst-standard-install: + +Standard Build and Install +========================== + +As described in section :ref:`inst-new-standard`, building and installing a module +distribution using the Distutils is usually one simple command:: + + python setup.py install + +On Unix, you'd run this command from a shell prompt; on Windows, you have to +open a command prompt window ("DOS box") and do it there; on Mac OS X, you open +a :command:`Terminal` window to get a shell prompt. + + +.. _inst-platform-variations: + +Platform variations +------------------- + +You should always run the setup command from the distribution root directory, +i.e. the top-level subdirectory that the module source distribution unpacks +into. For example, if you've just downloaded a module source distribution +:file:`foo-1.0.tar.gz` onto a Unix system, the normal thing to do is:: + + gunzip -c foo-1.0.tar.gz | tar xf - # unpacks into directory foo-1.0 + cd foo-1.0 + python setup.py install + +On Windows, you'd probably download :file:`foo-1.0.zip`. If you downloaded the +archive file to :file:`C:\\Temp`, then it would unpack into +:file:`C:\\Temp\\foo-1.0`; you can use either a archive manipulator with a +graphical user interface (such as WinZip) or a command-line tool (such as +:program:`unzip` or :program:`pkunzip`) to unpack the archive. Then, open a +command prompt window ("DOS box"), and run:: + + cd c:\Temp\foo-1.0 + python setup.py install + + +.. _inst-splitting-up: + +Splitting the job up +-------------------- + +Running ``setup.py install`` builds and installs all modules in one run. If you +prefer to work incrementally---especially useful if you want to customize the +build process, or if things are going wrong---you can use the setup script to do +one thing at a time. This is particularly helpful when the build and install +will be done by different users---for example, you might want to build a module +distribution and hand it off to a system administrator for installation (or do +it yourself, with super-user privileges). + +For example, you can build everything in one step, and then install everything +in a second step, by invoking the setup script twice:: + + python setup.py build + python setup.py install + +If you do this, you will notice that running the :command:`install` command +first runs the :command:`build` command, which---in this case---quickly notices +that it has nothing to do, since everything in the :file:`build` directory is +up-to-date. + +You may not need this ability to break things down often if all you do is +install modules downloaded off the 'net, but it's very handy for more advanced +tasks. If you get into distributing your own Python modules and extensions, +you'll run lots of individual Distutils commands on their own. + + +.. _inst-how-build-works: + +How building works +------------------ + +As implied above, the :command:`build` command is responsible for putting the +files to install into a *build directory*. By default, this is :file:`build` +under the distribution root; if you're excessively concerned with speed, or want +to keep the source tree pristine, you can change the build directory with the +:option:`--build-base` option. For example:: + + python setup.py build --build-base=/tmp/pybuild/foo-1.0 + +(Or you could do this permanently with a directive in your system or personal +Distutils configuration file; see section :ref:`inst-config-files`.) Normally, this +isn't necessary. + +The default layout for the build tree is as follows:: + + --- build/ --- lib/ + or + --- build/ --- lib./ + temp./ + +where ```` expands to a brief description of the current OS/hardware +platform and Python version. The first form, with just a :file:`lib` directory, +is used for "pure module distributions"---that is, module distributions that +include only pure Python modules. If a module distribution contains any +extensions (modules written in C/C++), then the second form, with two ```` +directories, is used. In that case, the :file:`temp.{plat}` directory holds +temporary files generated by the compile/link process that don't actually get +installed. In either case, the :file:`lib` (or :file:`lib.{plat}`) directory +contains all Python modules (pure Python and extensions) that will be installed. + +In the future, more directories will be added to handle Python scripts, +documentation, binary executables, and whatever else is needed to handle the job +of installing Python modules and applications. + + +.. _inst-how-install-works: + +How installation works +---------------------- + +After the :command:`build` command runs (whether you run it explicitly, or the +:command:`install` command does it for you), the work of the :command:`install` +command is relatively simple: all it has to do is copy everything under +:file:`build/lib` (or :file:`build/lib.{plat}`) to your chosen installation +directory. + +If you don't choose an installation directory---i.e., if you just run ``setup.py +install``\ ---then the :command:`install` command installs to the standard +location for third-party Python modules. This location varies by platform and +by how you built/installed Python itself. On Unix (and Mac OS X, which is also +Unix-based), it also depends on whether the module distribution being installed +is pure Python or contains extensions ("non-pure"): + ++-----------------+-----------------------------------------------------+--------------------------------------------------+-------+ +| Platform | Standard installation location | Default value | Notes | ++=================+=====================================================+==================================================+=======+ +| Unix (pure) | :file:`{prefix}/lib/python{X.Y}/site-packages` | :file:`/usr/local/lib/python{X.Y}/site-packages` | \(1) | ++-----------------+-----------------------------------------------------+--------------------------------------------------+-------+ +| Unix (non-pure) | :file:`{exec-prefix}/lib/python{X.Y}/site-packages` | :file:`/usr/local/lib/python{X.Y}/site-packages` | \(1) | ++-----------------+-----------------------------------------------------+--------------------------------------------------+-------+ +| Windows | :file:`{prefix}` | :file:`C:\\Python` | \(2) | ++-----------------+-----------------------------------------------------+--------------------------------------------------+-------+ + +Notes: + +(1) + Most Linux distributions include Python as a standard part of the system, so + :file:`{prefix}` and :file:`{exec-prefix}` are usually both :file:`/usr` on + Linux. If you build Python yourself on Linux (or any Unix-like system), the + default :file:`{prefix}` and :file:`{exec-prefix}` are :file:`/usr/local`. + +(2) + The default installation directory on Windows was :file:`C:\\Program + Files\\Python` under Python 1.6a1, 1.5.2, and earlier. + +:file:`{prefix}` and :file:`{exec-prefix}` stand for the directories that Python +is installed to, and where it finds its libraries at run-time. They are always +the same under Windows, and very often the same under Unix and Mac OS X. You +can find out what your Python installation uses for :file:`{prefix}` and +:file:`{exec-prefix}` by running Python in interactive mode and typing a few +simple commands. Under Unix, just type ``python`` at the shell prompt. Under +Windows, choose :menuselection:`Start --> Programs --> Python X.Y --> +Python (command line)`. Once the interpreter is started, you type Python code +at the prompt. For example, on my Linux system, I type the three Python +statements shown below, and get the output as shown, to find out my +:file:`{prefix}` and :file:`{exec-prefix}`:: + + Python 2.4 (#26, Aug 7 2004, 17:19:02) + Type "help", "copyright", "credits" or "license" for more information. + >>> import sys + >>> sys.prefix + '/usr' + >>> sys.exec_prefix + '/usr' + +If you don't want to install modules to the standard location, or if you don't +have permission to write there, then you need to read about alternate +installations in section :ref:`inst-alt-install`. If you want to customize your +installation directories more heavily, see section :ref:`inst-custom-install` on +custom installations. + + +.. _inst-alt-install: + +Alternate Installation +====================== + +Often, it is necessary or desirable to install modules to a location other than +the standard location for third-party Python modules. For example, on a Unix +system you might not have permission to write to the standard third-party module +directory. Or you might wish to try out a module before making it a standard +part of your local Python installation. This is especially true when upgrading +a distribution already present: you want to make sure your existing base of +scripts still works with the new version before actually upgrading. + +The Distutils :command:`install` command is designed to make installing module +distributions to an alternate location simple and painless. The basic idea is +that you supply a base directory for the installation, and the +:command:`install` command picks a set of directories (called an *installation +scheme*) under this base directory in which to install files. The details +differ across platforms, so read whichever of the following sections applies to +you. + + +.. _inst-alt-install-prefix: + +Alternate installation: the home scheme +--------------------------------------- + +The idea behind the "home scheme" is that you build and maintain a personal +stash of Python modules. This scheme's name is derived from the idea of a +"home" directory on Unix, since it's not unusual for a Unix user to make their +home directory have a layout similar to :file:`/usr/` or :file:`/usr/local/`. +This scheme can be used by anyone, regardless of the operating system their +installing for. + +Installing a new module distribution is as simple as :: + + python setup.py install --home= + +where you can supply any directory you like for the :option:`--home` option. On +Unix, lazy typists can just type a tilde (``~``); the :command:`install` command +will expand this to your home directory:: + + python setup.py install --home=~ + +The :option:`--home` option defines the installation base directory. Files are +installed to the following directories under the installation base as follows: + ++------------------------------+---------------------------+-----------------------------+ +| Type of file | Installation Directory | Override option | ++==============================+===========================+=============================+ +| pure module distribution | :file:`{home}/lib/python` | :option:`--install-purelib` | ++------------------------------+---------------------------+-----------------------------+ +| non-pure module distribution | :file:`{home}/lib/python` | :option:`--install-platlib` | ++------------------------------+---------------------------+-----------------------------+ +| scripts | :file:`{home}/bin` | :option:`--install-scripts` | ++------------------------------+---------------------------+-----------------------------+ +| data | :file:`{home}/share` | :option:`--install-data` | ++------------------------------+---------------------------+-----------------------------+ + +.. versionchanged:: 2.4 + The :option:`--home` option used to be supported only on Unix. + + +.. _inst-alt-install-home: + +Alternate installation: Unix (the prefix scheme) +------------------------------------------------ + +The "prefix scheme" is useful when you wish to use one Python installation to +perform the build/install (i.e., to run the setup script), but install modules +into the third-party module directory of a different Python installation (or +something that looks like a different Python installation). If this sounds a +trifle unusual, it is---that's why the "home scheme" comes first. However, +there are at least two known cases where the prefix scheme will be useful. + +First, consider that many Linux distributions put Python in :file:`/usr`, rather +than the more traditional :file:`/usr/local`. This is entirely appropriate, +since in those cases Python is part of "the system" rather than a local add-on. +However, if you are installing Python modules from source, you probably want +them to go in :file:`/usr/local/lib/python2.{X}` rather than +:file:`/usr/lib/python2.{X}`. This can be done with :: + + /usr/bin/python setup.py install --prefix=/usr/local + +Another possibility is a network filesystem where the name used to write to a +remote directory is different from the name used to read it: for example, the +Python interpreter accessed as :file:`/usr/local/bin/python` might search for +modules in :file:`/usr/local/lib/python2.{X}`, but those modules would have to +be installed to, say, :file:`/mnt/{@server}/export/lib/python2.{X}`. This could +be done with :: + + /usr/local/bin/python setup.py install --prefix=/mnt/@server/export + +In either case, the :option:`--prefix` option defines the installation base, and +the :option:`--exec-prefix` option defines the platform-specific installation +base, which is used for platform-specific files. (Currently, this just means +non-pure module distributions, but could be expanded to C libraries, binary +executables, etc.) If :option:`--exec-prefix` is not supplied, it defaults to +:option:`--prefix`. Files are installed as follows: + ++------------------------------+-----------------------------------------------------+-----------------------------+ +| Type of file | Installation Directory | Override option | ++==============================+=====================================================+=============================+ +| pure module distribution | :file:`{prefix}/lib/python{X.Y}/site-packages` | :option:`--install-purelib` | ++------------------------------+-----------------------------------------------------+-----------------------------+ +| non-pure module distribution | :file:`{exec-prefix}/lib/python{X.Y}/site-packages` | :option:`--install-platlib` | ++------------------------------+-----------------------------------------------------+-----------------------------+ +| scripts | :file:`{prefix}/bin` | :option:`--install-scripts` | ++------------------------------+-----------------------------------------------------+-----------------------------+ +| data | :file:`{prefix}/share` | :option:`--install-data` | ++------------------------------+-----------------------------------------------------+-----------------------------+ + +There is no requirement that :option:`--prefix` or :option:`--exec-prefix` +actually point to an alternate Python installation; if the directories listed +above do not already exist, they are created at installation time. + +Incidentally, the real reason the prefix scheme is important is simply that a +standard Unix installation uses the prefix scheme, but with :option:`--prefix` +and :option:`--exec-prefix` supplied by Python itself as ``sys.prefix`` and +``sys.exec_prefix``. Thus, you might think you'll never use the prefix scheme, +but every time you run ``python setup.py install`` without any other options, +you're using it. + +Note that installing extensions to an alternate Python installation has no +effect on how those extensions are built: in particular, the Python header files +(:file:`Python.h` and friends) installed with the Python interpreter used to run +the setup script will be used in compiling extensions. It is your +responsibility to ensure that the interpreter used to run extensions installed +in this way is compatible with the interpreter used to build them. The best way +to do this is to ensure that the two interpreters are the same version of Python +(possibly different builds, or possibly copies of the same build). (Of course, +if your :option:`--prefix` and :option:`--exec-prefix` don't even point to an +alternate Python installation, this is immaterial.) + + +.. _inst-alt-install-windows: + +Alternate installation: Windows (the prefix scheme) +--------------------------------------------------- + +Windows has no concept of a user's home directory, and since the standard Python +installation under Windows is simpler than under Unix, the :option:`--prefix` +option has traditionally been used to install additional packages in separate +locations on Windows. :: + + python setup.py install --prefix="\Temp\Python" + +to install modules to the :file:`\\Temp\\Python` directory on the current drive. + +The installation base is defined by the :option:`--prefix` option; the +:option:`--exec-prefix` option is not supported under Windows. Files are +installed as follows: + ++------------------------------+---------------------------+-----------------------------+ +| Type of file | Installation Directory | Override option | ++==============================+===========================+=============================+ +| pure module distribution | :file:`{prefix}` | :option:`--install-purelib` | ++------------------------------+---------------------------+-----------------------------+ +| non-pure module distribution | :file:`{prefix}` | :option:`--install-platlib` | ++------------------------------+---------------------------+-----------------------------+ +| scripts | :file:`{prefix}\\Scripts` | :option:`--install-scripts` | ++------------------------------+---------------------------+-----------------------------+ +| data | :file:`{prefix}\\Data` | :option:`--install-data` | ++------------------------------+---------------------------+-----------------------------+ + + +.. _inst-custom-install: + +Custom Installation +=================== + +Sometimes, the alternate installation schemes described in section +:ref:`inst-alt-install` just don't do what you want. You might want to tweak just +one or two directories while keeping everything under the same base directory, +or you might want to completely redefine the installation scheme. In either +case, you're creating a *custom installation scheme*. + +You probably noticed the column of "override options" in the tables describing +the alternate installation schemes above. Those options are how you define a +custom installation scheme. These override options can be relative, absolute, +or explicitly defined in terms of one of the installation base directories. +(There are two installation base directories, and they are normally the same--- +they only differ when you use the Unix "prefix scheme" and supply different +:option:`--prefix` and :option:`--exec-prefix` options.) + +For example, say you're installing a module distribution to your home directory +under Unix---but you want scripts to go in :file:`~/scripts` rather than +:file:`~/bin`. As you might expect, you can override this directory with the +:option:`--install-scripts` option; in this case, it makes most sense to supply +a relative path, which will be interpreted relative to the installation base +directory (your home directory, in this case):: + + python setup.py install --home=~ --install-scripts=scripts + +Another Unix example: suppose your Python installation was built and installed +with a prefix of :file:`/usr/local/python`, so under a standard installation +scripts will wind up in :file:`/usr/local/python/bin`. If you want them in +:file:`/usr/local/bin` instead, you would supply this absolute directory for the +:option:`--install-scripts` option:: + + python setup.py install --install-scripts=/usr/local/bin + +(This performs an installation using the "prefix scheme," where the prefix is +whatever your Python interpreter was installed with--- :file:`/usr/local/python` +in this case.) + +If you maintain Python on Windows, you might want third-party modules to live in +a subdirectory of :file:`{prefix}`, rather than right in :file:`{prefix}` +itself. This is almost as easy as customizing the script installation directory +---you just have to remember that there are two types of modules to worry about, +pure modules and non-pure modules (i.e., modules from a non-pure distribution). +For example:: + + python setup.py install --install-purelib=Site --install-platlib=Site + +The specified installation directories are relative to :file:`{prefix}`. Of +course, you also have to ensure that these directories are in Python's module +search path, such as by putting a :file:`.pth` file in :file:`{prefix}`. See +section :ref:`inst-search-path` to find out how to modify Python's search path. + +If you want to define an entire installation scheme, you just have to supply all +of the installation directory options. The recommended way to do this is to +supply relative paths; for example, if you want to maintain all Python +module-related files under :file:`python` in your home directory, and you want a +separate directory for each platform that you use your home directory from, you +might define the following installation scheme:: + + python setup.py install --home=~ \ + --install-purelib=python/lib \ + --install-platlib=python/lib.$PLAT \ + --install-scripts=python/scripts + --install-data=python/data + +or, equivalently, + +.. % $ % -- bow to font-lock + +:: + + python setup.py install --home=~/python \ + --install-purelib=lib \ + --install-platlib='lib.$PLAT' \ + --install-scripts=scripts + --install-data=data + +``$PLAT`` is not (necessarily) an environment variable---it will be expanded by +the Distutils as it parses your command line options, just as it does when +parsing your configuration file(s). + +.. % $ % -- bow to font-lock + +Obviously, specifying the entire installation scheme every time you install a +new module distribution would be very tedious. Thus, you can put these options +into your Distutils config file (see section :ref:`inst-config-files`):: + + [install] + install-base=$HOME + install-purelib=python/lib + install-platlib=python/lib.$PLAT + install-scripts=python/scripts + install-data=python/data + +or, equivalently, :: + + [install] + install-base=$HOME/python + install-purelib=lib + install-platlib=lib.$PLAT + install-scripts=scripts + install-data=data + +Note that these two are *not* equivalent if you supply a different installation +base directory when you run the setup script. For example, :: + + python setup.py install --install-base=/tmp + +would install pure modules to :file:`{/tmp/python/lib}` in the first case, and +to :file:`{/tmp/lib}` in the second case. (For the second case, you probably +want to supply an installation base of :file:`/tmp/python`.) + +You probably noticed the use of ``$HOME`` and ``$PLAT`` in the sample +configuration file input. These are Distutils configuration variables, which +bear a strong resemblance to environment variables. In fact, you can use +environment variables in config files on platforms that have such a notion but +the Distutils additionally define a few extra variables that may not be in your +environment, such as ``$PLAT``. (And of course, on systems that don't have +environment variables, such as Mac OS 9, the configuration variables supplied by +the Distutils are the only ones you can use.) See section :ref:`inst-config-files` +for details. + +.. % XXX need some Windows examples---when would custom +.. % installation schemes be needed on those platforms? + +.. % XXX I'm not sure where this section should go. + + +.. _inst-search-path: + +Modifying Python's Search Path +------------------------------ + +When the Python interpreter executes an :keyword:`import` statement, it searches +for both Python code and extension modules along a search path. A default value +for the path is configured into the Python binary when the interpreter is built. +You can determine the path by importing the :mod:`sys` module and printing the +value of ``sys.path``. :: + + $ python + Python 2.2 (#11, Oct 3 2002, 13:31:27) + [GCC 2.96 20000731 (Red Hat Linux 7.3 2.96-112)] on linux2 + Type ``help'', ``copyright'', ``credits'' or ``license'' for more information. + >>> import sys + >>> sys.path + ['', '/usr/local/lib/python2.3', '/usr/local/lib/python2.3/plat-linux2', + '/usr/local/lib/python2.3/lib-tk', '/usr/local/lib/python2.3/lib-dynload', + '/usr/local/lib/python2.3/site-packages'] + >>> + +The null string in ``sys.path`` represents the current working directory. + +.. % $ <-- bow to font-lock + +The expected convention for locally installed packages is to put them in the +:file:`{...}/site-packages/` directory, but you may want to install Python +modules into some arbitrary directory. For example, your site may have a +convention of keeping all software related to the web server under :file:`/www`. +Add-on Python modules might then belong in :file:`/www/python`, and in order to +import them, this directory must be added to ``sys.path``. There are several +different ways to add the directory. + +The most convenient way is to add a path configuration file to a directory +that's already on Python's path, usually to the :file:`.../site-packages/` +directory. Path configuration files have an extension of :file:`.pth`, and each +line must contain a single path that will be appended to ``sys.path``. (Because +the new paths are appended to ``sys.path``, modules in the added directories +will not override standard modules. This means you can't use this mechanism for +installing fixed versions of standard modules.) + +Paths can be absolute or relative, in which case they're relative to the +directory containing the :file:`.pth` file. Any directories added to the search +path will be scanned in turn for :file:`.pth` files. See `site module +documentation `_ for +more information. + +A slightly less convenient way is to edit the :file:`site.py` file in Python's +standard library, and modify ``sys.path``. :file:`site.py` is automatically +imported when the Python interpreter is executed, unless the :option:`-S` switch +is supplied to suppress this behaviour. So you could simply edit +:file:`site.py` and add two lines to it:: + + import sys + sys.path.append('/www/python/') + +However, if you reinstall the same major version of Python (perhaps when +upgrading from 2.2 to 2.2.2, for example) :file:`site.py` will be overwritten by +the stock version. You'd have to remember that it was modified and save a copy +before doing the installation. + +There are two environment variables that can modify ``sys.path``. +:envvar:`PYTHONHOME` sets an alternate value for the prefix of the Python +installation. For example, if :envvar:`PYTHONHOME` is set to ``/www/python``, +the search path will be set to ``['', '/www/python/lib/pythonX.Y/', +'/www/python/lib/pythonX.Y/plat-linux2', ...]``. + +The :envvar:`PYTHONPATH` variable can be set to a list of paths that will be +added to the beginning of ``sys.path``. For example, if :envvar:`PYTHONPATH` is +set to ``/www/python:/opt/py``, the search path will begin with +``['/www/python', '/opt/py']``. (Note that directories must exist in order to +be added to ``sys.path``; the :mod:`site` module removes paths that don't +exist.) + +Finally, ``sys.path`` is just a regular Python list, so any Python application +can modify it by adding or removing entries. + + +.. _inst-config-files: + +Distutils Configuration Files +============================= + +As mentioned above, you can use Distutils configuration files to record personal +or site preferences for any Distutils options. That is, any option to any +command can be stored in one of two or three (depending on your platform) +configuration files, which will be consulted before the command-line is parsed. +This means that configuration files will override default values, and the +command-line will in turn override configuration files. Furthermore, if +multiple configuration files apply, values from "earlier" files are overridden +by "later" files. + + +.. _inst-config-filenames: + +Location and names of config files +---------------------------------- + +The names and locations of the configuration files vary slightly across +platforms. On Unix and Mac OS X, the three configuration files (in the order +they are processed) are: + ++--------------+----------------------------------------------------------+-------+ +| Type of file | Location and filename | Notes | ++==============+==========================================================+=======+ +| system | :file:`{prefix}/lib/python{ver}/distutils/distutils.cfg` | \(1) | ++--------------+----------------------------------------------------------+-------+ +| personal | :file:`$HOME/.pydistutils.cfg` | \(2) | ++--------------+----------------------------------------------------------+-------+ +| local | :file:`setup.cfg` | \(3) | ++--------------+----------------------------------------------------------+-------+ + +And on Windows, the configuration files are: + ++--------------+-------------------------------------------------+-------+ +| Type of file | Location and filename | Notes | ++==============+=================================================+=======+ +| system | :file:`{prefix}\\Lib\\distutils\\distutils.cfg` | \(4) | ++--------------+-------------------------------------------------+-------+ +| personal | :file:`%HOME%\\pydistutils.cfg` | \(5) | ++--------------+-------------------------------------------------+-------+ +| local | :file:`setup.cfg` | \(3) | ++--------------+-------------------------------------------------+-------+ + +Notes: + +(1) + Strictly speaking, the system-wide configuration file lives in the directory + where the Distutils are installed; under Python 1.6 and later on Unix, this is + as shown. For Python 1.5.2, the Distutils will normally be installed to + :file:`{prefix}/lib/python1.5/site-packages/distutils`, so the system + configuration file should be put there under Python 1.5.2. + +(2) + On Unix, if the :envvar:`HOME` environment variable is not defined, the user's + home directory will be determined with the :func:`getpwuid` function from the + standard :mod:`pwd` module. + +(3) + I.e., in the current directory (usually the location of the setup script). + +(4) + (See also note (1).) Under Python 1.6 and later, Python's default "installation + prefix" is :file:`C:\\Python`, so the system configuration file is normally + :file:`C:\\Python\\Lib\\distutils\\distutils.cfg`. Under Python 1.5.2, the + default prefix was :file:`C:\\Program Files\\Python`, and the Distutils were not + part of the standard library---so the system configuration file would be + :file:`C:\\Program Files\\Python\\distutils\\distutils.cfg` in a standard Python + 1.5.2 installation under Windows. + +(5) + On Windows, if the :envvar:`HOME` environment variable is not defined, no + personal configuration file will be found or used. (In other words, the + Distutils make no attempt to guess your home directory on Windows.) + + +.. _inst-config-syntax: + +Syntax of config files +---------------------- + +The Distutils configuration files all have the same syntax. The config files +are grouped into sections. There is one section for each Distutils command, +plus a ``global`` section for global options that affect every command. Each +section consists of one option per line, specified as ``option=value``. + +For example, the following is a complete config file that just forces all +commands to run quietly by default:: + + [global] + verbose=0 + +If this is installed as the system config file, it will affect all processing of +any Python module distribution by any user on the current system. If it is +installed as your personal config file (on systems that support them), it will +affect only module distributions processed by you. And if it is used as the +:file:`setup.cfg` for a particular module distribution, it affects only that +distribution. + +You could override the default "build base" directory and make the +:command:`build\*` commands always forcibly rebuild all files with the +following:: + + [build] + build-base=blib + force=1 + +which corresponds to the command-line arguments :: + + python setup.py build --build-base=blib --force + +except that including the :command:`build` command on the command-line means +that command will be run. Including a particular command in config files has no +such implication; it only means that if the command is run, the options in the +config file will apply. (Or if other commands that derive values from it are +run, they will use the values in the config file.) + +You can find out the complete list of options for any command using the +:option:`--help` option, e.g.:: + + python setup.py build --help + +and you can find out the complete list of global options by using +:option:`--help` without a command:: + + python setup.py --help + +See also the "Reference" section of the "Distributing Python Modules" manual. + + +.. _inst-building-ext: + +Building Extensions: Tips and Tricks +==================================== + +Whenever possible, the Distutils try to use the configuration information made +available by the Python interpreter used to run the :file:`setup.py` script. +For example, the same compiler and linker flags used to compile Python will also +be used for compiling extensions. Usually this will work well, but in +complicated situations this might be inappropriate. This section discusses how +to override the usual Distutils behaviour. + + +.. _inst-tweak-flags: + +Tweaking compiler/linker flags +------------------------------ + +Compiling a Python extension written in C or C++ will sometimes require +specifying custom flags for the compiler and linker in order to use a particular +library or produce a special kind of object code. This is especially true if the +extension hasn't been tested on your platform, or if you're trying to +cross-compile Python. + +In the most general case, the extension author might have foreseen that +compiling the extensions would be complicated, and provided a :file:`Setup` file +for you to edit. This will likely only be done if the module distribution +contains many separate extension modules, or if they often require elaborate +sets of compiler flags in order to work. + +A :file:`Setup` file, if present, is parsed in order to get a list of extensions +to build. Each line in a :file:`Setup` describes a single module. Lines have +the following structure:: + + module ... [sourcefile ...] [cpparg ...] [library ...] + + +Let's examine each of the fields in turn. + +* *module* is the name of the extension module to be built, and should be a + valid Python identifier. You can't just change this in order to rename a module + (edits to the source code would also be needed), so this should be left alone. + +* *sourcefile* is anything that's likely to be a source code file, at least + judging by the filename. Filenames ending in :file:`.c` are assumed to be + written in C, filenames ending in :file:`.C`, :file:`.cc`, and :file:`.c++` are + assumed to be C++, and filenames ending in :file:`.m` or :file:`.mm` are assumed + to be in Objective C. + +* *cpparg* is an argument for the C preprocessor, and is anything starting with + :option:`-I`, :option:`-D`, :option:`-U` or :option:`-C`. + +* *library* is anything ending in :file:`.a` or beginning with :option:`-l` or + :option:`-L`. + +If a particular platform requires a special library on your platform, you can +add it by editing the :file:`Setup` file and running ``python setup.py build``. +For example, if the module defined by the line :: + + foo foomodule.c + +must be linked with the math library :file:`libm.a` on your platform, simply add +:option:`-lm` to the line:: + + foo foomodule.c -lm + +Arbitrary switches intended for the compiler or the linker can be supplied with +the :option:`-Xcompiler` *arg* and :option:`-Xlinker` *arg* options:: + + foo foomodule.c -Xcompiler -o32 -Xlinker -shared -lm + +The next option after :option:`-Xcompiler` and :option:`-Xlinker` will be +appended to the proper command line, so in the above example the compiler will +be passed the :option:`-o32` option, and the linker will be passed +:option:`-shared`. If a compiler option requires an argument, you'll have to +supply multiple :option:`-Xcompiler` options; for example, to pass ``-x c++`` +the :file:`Setup` file would have to contain ``-Xcompiler -x -Xcompiler c++``. + +Compiler flags can also be supplied through setting the :envvar:`CFLAGS` +environment variable. If set, the contents of :envvar:`CFLAGS` will be added to +the compiler flags specified in the :file:`Setup` file. + + +.. _inst-non-ms-compilers: + +Using non-Microsoft compilers on Windows +---------------------------------------- + +.. sectionauthor:: Rene Liebscher + + + +Borland C++ +^^^^^^^^^^^ + +This subsection describes the necessary steps to use Distutils with the Borland +C++ compiler version 5.5. First you have to know that Borland's object file +format (OMF) is different from the format used by the Python version you can +download from the Python or ActiveState Web site. (Python is built with +Microsoft Visual C++, which uses COFF as the object file format.) For this +reason you have to convert Python's library :file:`python25.lib` into the +Borland format. You can do this as follows: + +.. % Should we mention that users have to create cfg-files for the compiler? +.. % see also http://community.borland.com/article/0,1410,21205,00.html + +:: + + coff2omf python25.lib python25_bcpp.lib + +The :file:`coff2omf` program comes with the Borland compiler. The file +:file:`python25.lib` is in the :file:`Libs` directory of your Python +installation. If your extension uses other libraries (zlib, ...) you have to +convert them too. + +The converted files have to reside in the same directories as the normal +libraries. + +How does Distutils manage to use these libraries with their changed names? If +the extension needs a library (eg. :file:`foo`) Distutils checks first if it +finds a library with suffix :file:`_bcpp` (eg. :file:`foo_bcpp.lib`) and then +uses this library. In the case it doesn't find such a special library it uses +the default name (:file:`foo.lib`.) [#]_ + +To let Distutils compile your extension with Borland C++ you now have to type:: + + python setup.py build --compiler=bcpp + +If you want to use the Borland C++ compiler as the default, you could specify +this in your personal or system-wide configuration file for Distutils (see +section :ref:`inst-config-files`.) + + +.. seealso:: + + `C++Builder Compiler `_ + Information about the free C++ compiler from Borland, including links to the + download pages. + + `Creating Python Extensions Using Borland's Free Compiler `_ + Document describing how to use Borland's free command-line C++ compiler to build + Python. + + +GNU C / Cygwin / MinGW +^^^^^^^^^^^^^^^^^^^^^^ + +These instructions only apply if you're using a version of Python prior to +2.4.1 with a MinGW prior to 3.0.0 (with binutils-2.13.90-20030111-1). + +This section describes the necessary steps to use Distutils with the GNU C/C++ +compilers in their Cygwin and MinGW distributions. [#]_ For a Python interpreter +that was built with Cygwin, everything should work without any of these +following steps. + +These compilers require some special libraries. This task is more complex than +for Borland's C++, because there is no program to convert the library. First +you have to create a list of symbols which the Python DLL exports. (You can find +a good program for this task at +http://starship.python.net/crew/kernr/mingw32/Notes.html, see at PExports 0.42h +there.) + +.. % I don't understand what the next line means. --amk +.. % (inclusive the references on data structures.) + +:: + + pexports python25.dll >python25.def + +The location of an installed :file:`python25.dll` will depend on the +installation options and the version and language of Windows. In a "just for +me" installation, it will appear in the root of the installation directory. In +a shared installation, it will be located in the system directory. + +Then you can create from these information an import library for gcc. :: + + /cygwin/bin/dlltool --dllname python25.dll --def python25.def --output-lib libpython25.a + +The resulting library has to be placed in the same directory as +:file:`python25.lib`. (Should be the :file:`libs` directory under your Python +installation directory.) + +If your extension uses other libraries (zlib,...) you might have to convert +them too. The converted files have to reside in the same directories as the +normal libraries do. + +To let Distutils compile your extension with Cygwin you now have to type :: + + python setup.py build --compiler=cygwin + +and for Cygwin in no-cygwin mode [#]_ or for MinGW type:: + + python setup.py build --compiler=mingw32 + +If you want to use any of these options/compilers as default, you should +consider to write it in your personal or system-wide configuration file for +Distutils (see section :ref:`inst-config-files`.) + + +.. seealso:: + + `Building Python modules on MS Windows platform with MinGW `_ + Information about building the required libraries for the MinGW environment. + + http://pyopengl.sourceforge.net/ftp/win32-stuff/ + Converted import libraries in Cygwin/MinGW and Borland format, and a script to + create the registry entries needed for Distutils to locate the built Python. + +.. rubric:: Footnotes + +.. [#] This also means you could replace all existing COFF-libraries with OMF-libraries + of the same name. + +.. [#] Check http://sources.redhat.com/cygwin/ and http://www.mingw.org/ for more + information + +.. [#] Then you have no POSIX emulation available, but you also don't need + :file:`cygwin1.dll`. diff --git a/Doc/library/__builtin__.rst b/Doc/library/__builtin__.rst new file mode 100644 index 0000000..b3e1e11 --- /dev/null +++ b/Doc/library/__builtin__.rst @@ -0,0 +1,41 @@ + +:mod:`__builtin__` --- Built-in objects +======================================= + +.. module:: __builtin__ + :synopsis: The module that provides the built-in namespace. + + +This module provides direct access to all 'built-in' identifiers of Python; for +example, ``__builtin__.open`` is the full name for the built-in function +:func:`open`. See chapter :ref:`builtin`. + +This module is not normally accessed explicitly by most applications, but can be +useful in modules that provide objects with the same name as a built-in value, +but in which the built-in of that name is also needed. For example, in a module +that wants to implement an :func:`open` function that wraps the built-in +:func:`open`, this module can be used directly:: + + import __builtin__ + + def open(path): + f = __builtin__.open(path, 'r') + return UpperCaser(f) + + class UpperCaser: + '''Wrapper around a file that converts output to upper-case.''' + + def __init__(self, f): + self._f = f + + def read(self, count=-1): + return self._f.read(count).upper() + + # ... + +As an implementation detail, most modules have the name ``__builtins__`` (note +the ``'s'``) made available as part of their globals. The value of +``__builtins__`` is normally either this module or the value of this modules's +:attr:`__dict__` attribute. Since this is an implementation detail, it may not +be used by alternate implementations of Python. + diff --git a/Doc/library/__future__.rst b/Doc/library/__future__.rst new file mode 100644 index 0000000..6bf2830 --- /dev/null +++ b/Doc/library/__future__.rst @@ -0,0 +1,61 @@ + +:mod:`__future__` --- Future statement definitions +================================================== + +.. module:: __future__ + :synopsis: Future statement definitions + + +:mod:`__future__` is a real module, and serves three purposes: + +* To avoid confusing existing tools that analyze import statements and expect to + find the modules they're importing. + +* To ensure that future_statements run under releases prior to 2.1 at least + yield runtime exceptions (the import of :mod:`__future__` will fail, because + there was no module of that name prior to 2.1). + +* To document when incompatible changes were introduced, and when they will be + --- or were --- made mandatory. This is a form of executable documentation, and + can be inspected programatically via importing :mod:`__future__` and examining + its contents. + +Each statement in :file:`__future__.py` is of the form:: + + FeatureName = "_Feature(" OptionalRelease "," MandatoryRelease "," + CompilerFlag ")" + + +where, normally, *OptionalRelease* is less than *MandatoryRelease*, and both are +5-tuples of the same form as ``sys.version_info``:: + + (PY_MAJOR_VERSION, # the 2 in 2.1.0a3; an int + PY_MINOR_VERSION, # the 1; an int + PY_MICRO_VERSION, # the 0; an int + PY_RELEASE_LEVEL, # "alpha", "beta", "candidate" or "final"; string + PY_RELEASE_SERIAL # the 3; an int + ) + +*OptionalRelease* records the first release in which the feature was accepted. + +In the case of a *MandatoryRelease* that has not yet occurred, +*MandatoryRelease* predicts the release in which the feature will become part of +the language. + +Else *MandatoryRelease* records when the feature became part of the language; in +releases at or after that, modules no longer need a future statement to use the +feature in question, but may continue to use such imports. + +*MandatoryRelease* may also be ``None``, meaning that a planned feature got +dropped. + +Instances of class :class:`_Feature` have two corresponding methods, +:meth:`getOptionalRelease` and :meth:`getMandatoryRelease`. + +*CompilerFlag* is the (bitfield) flag that should be passed in the fourth +argument to the builtin function :func:`compile` to enable the feature in +dynamically compiled code. This flag is stored in the :attr:`compiler_flag` +attribute on :class:`_Feature` instances. + +No feature description will ever be deleted from :mod:`__future__`. + diff --git a/Doc/library/__main__.rst b/Doc/library/__main__.rst new file mode 100644 index 0000000..a1d3c24 --- /dev/null +++ b/Doc/library/__main__.rst @@ -0,0 +1,17 @@ + +:mod:`__main__` --- Top-level script environment +================================================ + +.. module:: __main__ + :synopsis: The environment where the top-level script is run. + + +This module represents the (otherwise anonymous) scope in which the +interpreter's main program executes --- commands read either from standard +input, from a script file, or from an interactive prompt. It is this +environment in which the idiomatic "conditional script" stanza causes a script +to run:: + + if __name__ == "__main__": + main() + diff --git a/Doc/library/_ast.rst b/Doc/library/_ast.rst new file mode 100644 index 0000000..9b195be --- /dev/null +++ b/Doc/library/_ast.rst @@ -0,0 +1,59 @@ +.. _ast: + +Abstract Syntax Trees +===================== + +.. module:: _ast + :synopsis: Abstract Syntax Tree classes. + +.. sectionauthor:: Martin v. Löwis + + +.. versionadded:: 2.5 + +The ``_ast`` module helps Python applications to process trees of the Python +abstract syntax grammar. The Python compiler currently provides read-only access +to such trees, meaning that applications can only create a tree for a given +piece of Python source code; generating byte code from a (potentially modified) +tree is not supported. The abstract syntax itself might change with each Python +release; this module helps to find out programmatically what the current grammar +looks like. + +An abstract syntax tree can be generated by passing ``_ast.PyCF_ONLY_AST`` as a +flag to the :func:`compile` builtin function. The result will be a tree of +objects whose classes all inherit from ``_ast.AST``. + +The actual classes are derived from the ``Parser/Python.asdl`` file, which is +reproduced below. There is one class defined for each left-hand side symbol in +the abstract grammar (for example, ``_ast.stmt`` or ``_ast.expr``). In addition, +there is one class defined for each constructor on the right-hand side; these +classes inherit from the classes for the left-hand side trees. For example, +``_ast.BinOp`` inherits from ``_ast.expr``. For production rules with +alternatives (aka "sums"), the left-hand side class is abstract: only instances +of specific constructor nodes are ever created. + +Each concrete class has an attribute ``_fields`` which gives the names of all +child nodes. + +Each instance of a concrete class has one attribute for each child node, of the +type as defined in the grammar. For example, ``_ast.BinOp`` instances have an +attribute ``left`` of type ``_ast.expr``. Instances of ``_ast.expr`` and +``_ast.stmt`` subclasses also have lineno and col_offset attributes. The lineno +is the line number of source text (1 indexed so the first line is line 1) and +the col_offset is the utf8 byte offset of the first token that generated the +node. The utf8 offset is recorded because the parser uses utf8 internally. + +If these attributes are marked as optional in the grammar (using a question +mark), the value might be ``None``. If the attributes can have zero-or-more +values (marked with an asterisk), the values are represented as Python lists. + + +Abstract Grammar +---------------- + +The module defines a string constant ``__version__`` which is the decimal +subversion revision number of the file shown below. + +The abstract grammar is currently defined as follows: + +.. literalinclude:: ../../Parser/Python.asdl diff --git a/Doc/library/_winreg.rst b/Doc/library/_winreg.rst new file mode 100644 index 0000000..fddbfd1 --- /dev/null +++ b/Doc/library/_winreg.rst @@ -0,0 +1,420 @@ + +:mod:`_winreg` -- Windows registry access +========================================= + +.. module:: _winreg + :platform: Windows + :synopsis: Routines and objects for manipulating the Windows registry. +.. sectionauthor:: Mark Hammond + + +.. versionadded:: 2.0 + +These functions expose the Windows registry API to Python. Instead of using an +integer as the registry handle, a handle object is used to ensure that the +handles are closed correctly, even if the programmer neglects to explicitly +close them. + +This module exposes a very low-level interface to the Windows registry; it is +expected that in the future a new ``winreg`` module will be created offering a +higher-level interface to the registry API. + +This module offers the following functions: + + +.. function:: CloseKey(hkey) + + Closes a previously opened registry key. The hkey argument specifies a + previously opened key. + + Note that if *hkey* is not closed using this method (or via + :meth:`handle.Close`), it is closed when the *hkey* object is destroyed by + Python. + + +.. function:: ConnectRegistry(computer_name, key) + + Establishes a connection to a predefined registry handle on another computer, + and returns a :dfn:`handle object` + + *computer_name* is the name of the remote computer, of the form + ``r"\\computername"``. If ``None``, the local computer is used. + + *key* is the predefined handle to connect to. + + The return value is the handle of the opened key. If the function fails, an + :exc:`EnvironmentError` exception is raised. + + +.. function:: CreateKey(key, sub_key) + + Creates or opens the specified key, returning a :dfn:`handle object` + + *key* is an already open key, or one of the predefined :const:`HKEY_\*` + constants. + + *sub_key* is a string that names the key this method opens or creates. + + If *key* is one of the predefined keys, *sub_key* may be ``None``. In that + case, the handle returned is the same key handle passed in to the function. + + If the key already exists, this function opens the existing key. + + The return value is the handle of the opened key. If the function fails, an + :exc:`EnvironmentError` exception is raised. + + +.. function:: DeleteKey(key, sub_key) + + Deletes the specified key. + + *key* is an already open key, or any one of the predefined :const:`HKEY_\*` + constants. + + *sub_key* is a string that must be a subkey of the key identified by the *key* + parameter. This value must not be ``None``, and the key may not have subkeys. + + *This method can not delete keys with subkeys.* + + If the method succeeds, the entire key, including all of its values, is removed. + If the method fails, an :exc:`EnvironmentError` exception is raised. + + +.. function:: DeleteValue(key, value) + + Removes a named value from a registry key. + + *key* is an already open key, or one of the predefined :const:`HKEY_\*` + constants. + + *value* is a string that identifies the value to remove. + + +.. function:: EnumKey(key, index) + + Enumerates subkeys of an open registry key, returning a string. + + *key* is an already open key, or any one of the predefined :const:`HKEY_\*` + constants. + + *index* is an integer that identifies the index of the key to retrieve. + + The function retrieves the name of one subkey each time it is called. It is + typically called repeatedly until an :exc:`EnvironmentError` exception is + raised, indicating, no more values are available. + + +.. function:: EnumValue(key, index) + + Enumerates values of an open registry key, returning a tuple. + + *key* is an already open key, or any one of the predefined :const:`HKEY_\*` + constants. + + *index* is an integer that identifies the index of the value to retrieve. + + The function retrieves the name of one subkey each time it is called. It is + typically called repeatedly, until an :exc:`EnvironmentError` exception is + raised, indicating no more values. + + The result is a tuple of 3 items: + + +-------+--------------------------------------------+ + | Index | Meaning | + +=======+============================================+ + | ``0`` | A string that identifies the value name | + +-------+--------------------------------------------+ + | ``1`` | An object that holds the value data, and | + | | whose type depends on the underlying | + | | registry type | + +-------+--------------------------------------------+ + | ``2`` | An integer that identifies the type of the | + | | value data | + +-------+--------------------------------------------+ + + +.. function:: FlushKey(key) + + Writes all the attributes of a key to the registry. + + *key* is an already open key, or one of the predefined :const:`HKEY_\*` + constants. + + It is not necessary to call RegFlushKey to change a key. Registry changes are + flushed to disk by the registry using its lazy flusher. Registry changes are + also flushed to disk at system shutdown. Unlike :func:`CloseKey`, the + :func:`FlushKey` method returns only when all the data has been written to the + registry. An application should only call :func:`FlushKey` if it requires + absolute certainty that registry changes are on disk. + + .. note:: + + If you don't know whether a :func:`FlushKey` call is required, it probably + isn't. + + +.. function:: RegLoadKey(key, sub_key, file_name) + + Creates a subkey under the specified key and stores registration information + from a specified file into that subkey. + + *key* is an already open key, or any of the predefined :const:`HKEY_\*` + constants. + + *sub_key* is a string that identifies the sub_key to load. + + *file_name* is the name of the file to load registry data from. This file must + have been created with the :func:`SaveKey` function. Under the file allocation + table (FAT) file system, the filename may not have an extension. + + A call to LoadKey() fails if the calling process does not have the + :const:`SE_RESTORE_PRIVILEGE` privilege. Note that privileges are different than + permissions - see the Win32 documentation for more details. + + If *key* is a handle returned by :func:`ConnectRegistry`, then the path + specified in *fileName* is relative to the remote computer. + + The Win32 documentation implies *key* must be in the :const:`HKEY_USER` or + :const:`HKEY_LOCAL_MACHINE` tree. This may or may not be true. + + +.. function:: OpenKey(key, sub_key[, res=0][, sam=KEY_READ]) + + Opens the specified key, returning a :dfn:`handle object` + + *key* is an already open key, or any one of the predefined :const:`HKEY_\*` + constants. + + *sub_key* is a string that identifies the sub_key to open. + + *res* is a reserved integer, and must be zero. The default is zero. + + *sam* is an integer that specifies an access mask that describes the desired + security access for the key. Default is :const:`KEY_READ` + + The result is a new handle to the specified key. + + If the function fails, :exc:`EnvironmentError` is raised. + + +.. function:: OpenKeyEx() + + The functionality of :func:`OpenKeyEx` is provided via :func:`OpenKey`, by the + use of default arguments. + + +.. function:: QueryInfoKey(key) + + Returns information about a key, as a tuple. + + *key* is an already open key, or one of the predefined :const:`HKEY_\*` + constants. + + The result is a tuple of 3 items: + + +-------+---------------------------------------------+ + | Index | Meaning | + +=======+=============================================+ + | ``0`` | An integer giving the number of sub keys | + | | this key has. | + +-------+---------------------------------------------+ + | ``1`` | An integer giving the number of values this | + | | key has. | + +-------+---------------------------------------------+ + | ``2`` | A long integer giving when the key was last | + | | modified (if available) as 100's of | + | | nanoseconds since Jan 1, 1600. | + +-------+---------------------------------------------+ + + +.. function:: QueryValue(key, sub_key) + + Retrieves the unnamed value for a key, as a string + + *key* is an already open key, or one of the predefined :const:`HKEY_\*` + constants. + + *sub_key* is a string that holds the name of the subkey with which the value is + associated. If this parameter is ``None`` or empty, the function retrieves the + value set by the :func:`SetValue` method for the key identified by *key*. + + Values in the registry have name, type, and data components. This method + retrieves the data for a key's first value that has a NULL name. But the + underlying API call doesn't return the type, Lame Lame Lame, DO NOT USE THIS!!! + + +.. function:: QueryValueEx(key, value_name) + + Retrieves the type and data for a specified value name associated with an open + registry key. + + *key* is an already open key, or one of the predefined :const:`HKEY_\*` + constants. + + *value_name* is a string indicating the value to query. + + The result is a tuple of 2 items: + + +-------+-----------------------------------------+ + | Index | Meaning | + +=======+=========================================+ + | ``0`` | The value of the registry item. | + +-------+-----------------------------------------+ + | ``1`` | An integer giving the registry type for | + | | this value. | + +-------+-----------------------------------------+ + + +.. function:: SaveKey(key, file_name) + + Saves the specified key, and all its subkeys to the specified file. + + *key* is an already open key, or one of the predefined :const:`HKEY_\*` + constants. + + *file_name* is the name of the file to save registry data to. This file cannot + already exist. If this filename includes an extension, it cannot be used on file + allocation table (FAT) file systems by the :meth:`LoadKey`, :meth:`ReplaceKey` + or :meth:`RestoreKey` methods. + + If *key* represents a key on a remote computer, the path described by + *file_name* is relative to the remote computer. The caller of this method must + possess the :const:`SeBackupPrivilege` security privilege. Note that + privileges are different than permissions - see the Win32 documentation for + more details. + + This function passes NULL for *security_attributes* to the API. + + +.. function:: SetValue(key, sub_key, type, value) + + Associates a value with a specified key. + + *key* is an already open key, or one of the predefined :const:`HKEY_\*` + constants. + + *sub_key* is a string that names the subkey with which the value is associated. + + *type* is an integer that specifies the type of the data. Currently this must be + :const:`REG_SZ`, meaning only strings are supported. Use the :func:`SetValueEx` + function for support for other data types. + + *value* is a string that specifies the new value. + + If the key specified by the *sub_key* parameter does not exist, the SetValue + function creates it. + + Value lengths are limited by available memory. Long values (more than 2048 + bytes) should be stored as files with the filenames stored in the configuration + registry. This helps the registry perform efficiently. + + The key identified by the *key* parameter must have been opened with + :const:`KEY_SET_VALUE` access. + + +.. function:: SetValueEx(key, value_name, reserved, type, value) + + Stores data in the value field of an open registry key. + + *key* is an already open key, or one of the predefined :const:`HKEY_\*` + constants. + + *value_name* is a string that names the subkey with which the value is + associated. + + *type* is an integer that specifies the type of the data. This should be one + of the following constants defined in this module: + + +----------------------------------+---------------------------------------------+ + | Constant | Meaning | + +==================================+=============================================+ + | :const:`REG_BINARY` | Binary data in any form. | + +----------------------------------+---------------------------------------------+ + | :const:`REG_DWORD` | A 32-bit number. | + +----------------------------------+---------------------------------------------+ + | :const:`REG_DWORD_LITTLE_ENDIAN` | A 32-bit number in little-endian format. | + +----------------------------------+---------------------------------------------+ + | :const:`REG_DWORD_BIG_ENDIAN` | A 32-bit number in big-endian format. | + +----------------------------------+---------------------------------------------+ + | :const:`REG_EXPAND_SZ` | Null-terminated string containing | + | | references to environment variables | + | | (``%PATH%``). | + +----------------------------------+---------------------------------------------+ + | :const:`REG_LINK` | A Unicode symbolic link. | + +----------------------------------+---------------------------------------------+ + | :const:`REG_MULTI_SZ` | A sequence of null-terminated strings, | + | | terminated by two null characters. (Python | + | | handles this termination automatically.) | + +----------------------------------+---------------------------------------------+ + | :const:`REG_NONE` | No defined value type. | + +----------------------------------+---------------------------------------------+ + | :const:`REG_RESOURCE_LIST` | A device-driver resource list. | + +----------------------------------+---------------------------------------------+ + | :const:`REG_SZ` | A null-terminated string. | + +----------------------------------+---------------------------------------------+ + + *reserved* can be anything - zero is always passed to the API. + + *value* is a string that specifies the new value. + + This method can also set additional value and type information for the specified + key. The key identified by the key parameter must have been opened with + :const:`KEY_SET_VALUE` access. + + To open the key, use the :func:`CreateKeyEx` or :func:`OpenKey` methods. + + Value lengths are limited by available memory. Long values (more than 2048 + bytes) should be stored as files with the filenames stored in the configuration + registry. This helps the registry perform efficiently. + + +.. _handle-object: + +Registry Handle Objects +----------------------- + +This object wraps a Windows HKEY object, automatically closing it when the +object is destroyed. To guarantee cleanup, you can call either the +:meth:`Close` method on the object, or the :func:`CloseKey` function. + +All registry functions in this module return one of these objects. + +All registry functions in this module which accept a handle object also accept +an integer, however, use of the handle object is encouraged. + +Handle objects provide semantics for :meth:`__bool__` - thus :: + + if handle: + print "Yes" + +will print ``Yes`` if the handle is currently valid (has not been closed or +detached). + +The object also support comparison semantics, so handle objects will compare +true if they both reference the same underlying Windows handle value. + +Handle objects can be converted to an integer (e.g., using the builtin +:func:`int` function), in which case the underlying Windows handle value is +returned. You can also use the :meth:`Detach` method to return the integer +handle, and also disconnect the Windows handle from the handle object. + + +.. method:: PyHKEY.Close() + + Closes the underlying Windows handle. + + If the handle is already closed, no error is raised. + + +.. method:: PyHKEY.Detach() + + Detaches the Windows handle from the handle object. + + The result is an integer (or long on 64 bit Windows) that holds the value of the + handle before it is detached. If the handle is already detached or closed, this + will return zero. + + After calling this function, the handle is effectively invalidated, but the + handle is not closed. You would call this function when you need the + underlying Win32 handle to exist beyond the lifetime of the handle object. + diff --git a/Doc/library/aepack.rst b/Doc/library/aepack.rst new file mode 100644 index 0000000..7eaffd8 --- /dev/null +++ b/Doc/library/aepack.rst @@ -0,0 +1,92 @@ + +:mod:`aepack` --- Conversion between Python variables and AppleEvent data containers +==================================================================================== + +.. module:: aepack + :platform: Mac + :synopsis: Conversion between Python variables and AppleEvent data containers. +.. sectionauthor:: Vincent Marchetti + + +.. % \moduleauthor{Jack Jansen?}{email} + +The :mod:`aepack` module defines functions for converting (packing) Python +variables to AppleEvent descriptors and back (unpacking). Within Python the +AppleEvent descriptor is handled by Python objects of built-in type +:class:`AEDesc`, defined in module :mod:`Carbon.AE`. + +The :mod:`aepack` module defines the following functions: + + +.. function:: pack(x[, forcetype]) + + Returns an :class:`AEDesc` object containing a conversion of Python value x. If + *forcetype* is provided it specifies the descriptor type of the result. + Otherwise, a default mapping of Python types to Apple Event descriptor types is + used, as follows: + + +-----------------+-----------------------------------+ + | Python type | descriptor type | + +=================+===================================+ + | :class:`FSSpec` | typeFSS | + +-----------------+-----------------------------------+ + | :class:`FSRef` | typeFSRef | + +-----------------+-----------------------------------+ + | :class:`Alias` | typeAlias | + +-----------------+-----------------------------------+ + | integer | typeLong (32 bit integer) | + +-----------------+-----------------------------------+ + | float | typeFloat (64 bit floating point) | + +-----------------+-----------------------------------+ + | string | typeText | + +-----------------+-----------------------------------+ + | unicode | typeUnicodeText | + +-----------------+-----------------------------------+ + | list | typeAEList | + +-----------------+-----------------------------------+ + | dictionary | typeAERecord | + +-----------------+-----------------------------------+ + | instance | *see below* | + +-----------------+-----------------------------------+ + + If *x* is a Python instance then this function attempts to call an + :meth:`__aepack__` method. This method should return an :class:`AEDesc` object. + + If the conversion *x* is not defined above, this function returns the Python + string representation of a value (the repr() function) encoded as a text + descriptor. + + +.. function:: unpack(x[, formodulename]) + + *x* must be an object of type :class:`AEDesc`. This function returns a Python + object representation of the data in the Apple Event descriptor *x*. Simple + AppleEvent data types (integer, text, float) are returned as their obvious + Python counterparts. Apple Event lists are returned as Python lists, and the + list elements are recursively unpacked. Object references (ex. ``line 3 of + document 1``) are returned as instances of :class:`aetypes.ObjectSpecifier`, + unless ``formodulename`` is specified. AppleEvent descriptors with descriptor + type typeFSS are returned as :class:`FSSpec` objects. AppleEvent record + descriptors are returned as Python dictionaries, with 4-character string keys + and elements recursively unpacked. + + The optional ``formodulename`` argument is used by the stub packages generated + by :mod:`gensuitemodule`, and ensures that the OSA classes for object specifiers + are looked up in the correct module. This ensures that if, say, the Finder + returns an object specifier for a window you get an instance of + ``Finder.Window`` and not a generic ``aetypes.Window``. The former knows about + all the properties and elements a window has in the Finder, while the latter + knows no such things. + + +.. seealso:: + + Module :mod:`Carbon.AE` + Built-in access to Apple Event Manager routines. + + Module :mod:`aetypes` + Python definitions of codes for Apple Event descriptor types. + + ` Inside Macintosh: Interapplication Communication `_ + Information about inter-process communications on the Macintosh. + diff --git a/Doc/library/aetools.rst b/Doc/library/aetools.rst new file mode 100644 index 0000000..b5fd4ad --- /dev/null +++ b/Doc/library/aetools.rst @@ -0,0 +1,86 @@ + +:mod:`aetools` --- OSA client support +===================================== + +.. module:: aetools + :platform: Mac + :synopsis: Basic support for sending Apple Events +.. sectionauthor:: Jack Jansen + + +.. % \moduleauthor{Jack Jansen?}{email} + +The :mod:`aetools` module contains the basic functionality on which Python +AppleScript client support is built. It also imports and re-exports the core +functionality of the :mod:`aetypes` and :mod:`aepack` modules. The stub packages +generated by :mod:`gensuitemodule` import the relevant portions of +:mod:`aetools`, so usually you do not need to import it yourself. The exception +to this is when you cannot use a generated suite package and need lower-level +access to scripting. + +The :mod:`aetools` module itself uses the AppleEvent support provided by the +:mod:`Carbon.AE` module. This has one drawback: you need access to the window +manager, see section :ref:`osx-gui-scripts` for details. This restriction may be +lifted in future releases. + +The :mod:`aetools` module defines the following functions: + + +.. function:: packevent(ae, parameters, attributes) + + Stores parameters and attributes in a pre-created ``Carbon.AE.AEDesc`` object. + ``parameters`` and ``attributes`` are dictionaries mapping 4-character OSA + parameter keys to Python objects. The objects are packed using + ``aepack.pack()``. + + +.. function:: unpackevent(ae[, formodulename]) + + Recursively unpacks a ``Carbon.AE.AEDesc`` event to Python objects. The function + returns the parameter dictionary and the attribute dictionary. The + ``formodulename`` argument is used by generated stub packages to control where + AppleScript classes are looked up. + + +.. function:: keysubst(arguments, keydict) + + Converts a Python keyword argument dictionary ``arguments`` to the format + required by ``packevent`` by replacing the keys, which are Python identifiers, + by the four-character OSA keys according to the mapping specified in + ``keydict``. Used by the generated suite packages. + + +.. function:: enumsubst(arguments, key, edict) + + If the ``arguments`` dictionary contains an entry for ``key`` convert the value + for that entry according to dictionary ``edict``. This converts human-readable + Python enumeration names to the OSA 4-character codes. Used by the generated + suite packages. + +The :mod:`aetools` module defines the following class: + + +.. class:: TalkTo([signature=None, start=0, timeout=0]) + + Base class for the proxy used to talk to an application. ``signature`` overrides + the class attribute ``_signature`` (which is usually set by subclasses) and is + the 4-char creator code defining the application to talk to. ``start`` can be + set to true to enable running the application on class instantiation. + ``timeout`` can be specified to change the default timeout used while waiting + for an AppleEvent reply. + + +.. method:: TalkTo._start() + + Test whether the application is running, and attempt to start it if not. + + +.. method:: TalkTo.send(code, subcode[, parameters, attributes]) + + Create the AppleEvent ``Carbon.AE.AEDesc`` for the verb with the OSA designation + ``code, subcode`` (which are the usual 4-character strings), pack the + ``parameters`` and ``attributes`` into it, send it to the target application, + wait for the reply, unpack the reply with ``unpackevent`` and return the reply + appleevent, the unpacked return values as a dictionary and the return + attributes. + diff --git a/Doc/library/aetypes.rst b/Doc/library/aetypes.rst new file mode 100644 index 0000000..0dd0a88 --- /dev/null +++ b/Doc/library/aetypes.rst @@ -0,0 +1,150 @@ + +:mod:`aetypes` --- AppleEvent objects +===================================== + +.. module:: aetypes + :platform: Mac + :synopsis: Python representation of the Apple Event Object Model. +.. sectionauthor:: Vincent Marchetti + + +.. % \moduleauthor{Jack Jansen?}{email} + +The :mod:`aetypes` defines classes used to represent Apple Event data +descriptors and Apple Event object specifiers. + +Apple Event data is contained in descriptors, and these descriptors are typed. +For many descriptors the Python representation is simply the corresponding +Python type: ``typeText`` in OSA is a Python string, ``typeFloat`` is a float, +etc. For OSA types that have no direct Python counterpart this module declares +classes. Packing and unpacking instances of these classes is handled +automatically by :mod:`aepack`. + +An object specifier is essentially an address of an object implemented in a +Apple Event server. An Apple Event specifier is used as the direct object for an +Apple Event or as the argument of an optional parameter. The :mod:`aetypes` +module contains the base classes for OSA classes and properties, which are used +by the packages generated by :mod:`gensuitemodule` to populate the classes and +properties in a given suite. + +For reasons of backward compatibility, and for cases where you need to script an +application for which you have not generated the stub package this module also +contains object specifiers for a number of common OSA classes such as +``Document``, ``Window``, ``Character``, etc. + +The :mod:`AEObjects` module defines the following classes to represent Apple +Event descriptor data: + + +.. class:: Unknown(type, data) + + The representation of OSA descriptor data for which the :mod:`aepack` and + :mod:`aetypes` modules have no support, i.e. anything that is not represented by + the other classes here and that is not equivalent to a simple Python value. + + +.. class:: Enum(enum) + + An enumeration value with the given 4-character string value. + + +.. class:: InsertionLoc(of, pos) + + Position ``pos`` in object ``of``. + + +.. class:: Boolean(bool) + + A boolean. + + +.. class:: StyledText(style, text) + + Text with style information (font, face, etc) included. + + +.. class:: AEText(script, style, text) + + Text with script system and style information included. + + +.. class:: IntlText(script, language, text) + + Text with script system and language information included. + + +.. class:: IntlWritingCode(script, language) + + Script system and language information. + + +.. class:: QDPoint(v, h) + + A quickdraw point. + + +.. class:: QDRectangle(v0, h0, v1, h1) + + A quickdraw rectangle. + + +.. class:: RGBColor(r, g, b) + + A color. + + +.. class:: Type(type) + + An OSA type value with the given 4-character name. + + +.. class:: Keyword(name) + + An OSA keyword with the given 4-character name. + + +.. class:: Range(start, stop) + + A range. + + +.. class:: Ordinal(abso) + + Non-numeric absolute positions, such as ``"firs"``, first, or ``"midd"``, + middle. + + +.. class:: Logical(logc, term) + + The logical expression of applying operator ``logc`` to ``term``. + + +.. class:: Comparison(obj1, relo, obj2) + + The comparison ``relo`` of ``obj1`` to ``obj2``. + +The following classes are used as base classes by the generated stub packages to +represent AppleScript classes and properties in Python: + + +.. class:: ComponentItem(which[, fr]) + + Abstract baseclass for an OSA class. The subclass should set the class attribute + ``want`` to the 4-character OSA class code. Instances of subclasses of this + class are equivalent to AppleScript Object Specifiers. Upon instantiation you + should pass a selector in ``which``, and optionally a parent object in ``fr``. + + +.. class:: NProperty(fr) + + Abstract baseclass for an OSA property. The subclass should set the class + attributes ``want`` and ``which`` to designate which property we are talking + about. Instances of subclasses of this class are Object Specifiers. + + +.. class:: ObjectSpecifier(want, form, seld[, fr]) + + Base class of ``ComponentItem`` and ``NProperty``, a general OSA Object + Specifier. See the Apple Open Scripting Architecture documentation for the + parameters. Note that this class is not abstract. + diff --git a/Doc/library/aifc.rst b/Doc/library/aifc.rst new file mode 100644 index 0000000..0cfcb52 --- /dev/null +++ b/Doc/library/aifc.rst @@ -0,0 +1,225 @@ + +:mod:`aifc` --- Read and write AIFF and AIFC files +================================================== + +.. module:: aifc + :synopsis: Read and write audio files in AIFF or AIFC format. + + +.. index:: + single: Audio Interchange File Format + single: AIFF + single: AIFF-C + +This module provides support for reading and writing AIFF and AIFF-C files. +AIFF is Audio Interchange File Format, a format for storing digital audio +samples in a file. AIFF-C is a newer version of the format that includes the +ability to compress the audio data. + +**Caveat:** Some operations may only work under IRIX; these will raise +:exc:`ImportError` when attempting to import the :mod:`cl` module, which is only +available on IRIX. + +Audio files have a number of parameters that describe the audio data. The +sampling rate or frame rate is the number of times per second the sound is +sampled. The number of channels indicate if the audio is mono, stereo, or +quadro. Each frame consists of one sample per channel. The sample size is the +size in bytes of each sample. Thus a frame consists of +*nchannels*\**samplesize* bytes, and a second's worth of audio consists of +*nchannels*\**samplesize*\**framerate* bytes. + +For example, CD quality audio has a sample size of two bytes (16 bits), uses two +channels (stereo) and has a frame rate of 44,100 frames/second. This gives a +frame size of 4 bytes (2\*2), and a second's worth occupies 2\*2\*44100 bytes +(176,400 bytes). + +Module :mod:`aifc` defines the following function: + + +.. function:: open(file[, mode]) + + Open an AIFF or AIFF-C file and return an object instance with methods that are + described below. The argument *file* is either a string naming a file or a file + object. *mode* must be ``'r'`` or ``'rb'`` when the file must be opened for + reading, or ``'w'`` or ``'wb'`` when the file must be opened for writing. If + omitted, ``file.mode`` is used if it exists, otherwise ``'rb'`` is used. When + used for writing, the file object should be seekable, unless you know ahead of + time how many samples you are going to write in total and use + :meth:`writeframesraw` and :meth:`setnframes`. + +Objects returned by :func:`open` when a file is opened for reading have the +following methods: + + +.. method:: aifc.getnchannels() + + Return the number of audio channels (1 for mono, 2 for stereo). + + +.. method:: aifc.getsampwidth() + + Return the size in bytes of individual samples. + + +.. method:: aifc.getframerate() + + Return the sampling rate (number of audio frames per second). + + +.. method:: aifc.getnframes() + + Return the number of audio frames in the file. + + +.. method:: aifc.getcomptype() + + Return a four-character string describing the type of compression used in the + audio file. For AIFF files, the returned value is ``'NONE'``. + + +.. method:: aifc.getcompname() + + Return a human-readable description of the type of compression used in the audio + file. For AIFF files, the returned value is ``'not compressed'``. + + +.. method:: aifc.getparams() + + Return a tuple consisting of all of the above values in the above order. + + +.. method:: aifc.getmarkers() + + Return a list of markers in the audio file. A marker consists of a tuple of + three elements. The first is the mark ID (an integer), the second is the mark + position in frames from the beginning of the data (an integer), the third is the + name of the mark (a string). + + +.. method:: aifc.getmark(id) + + Return the tuple as described in :meth:`getmarkers` for the mark with the given + *id*. + + +.. method:: aifc.readframes(nframes) + + Read and return the next *nframes* frames from the audio file. The returned + data is a string containing for each frame the uncompressed samples of all + channels. + + +.. method:: aifc.rewind() + + Rewind the read pointer. The next :meth:`readframes` will start from the + beginning. + + +.. method:: aifc.setpos(pos) + + Seek to the specified frame number. + + +.. method:: aifc.tell() + + Return the current frame number. + + +.. method:: aifc.close() + + Close the AIFF file. After calling this method, the object can no longer be + used. + +Objects returned by :func:`open` when a file is opened for writing have all the +above methods, except for :meth:`readframes` and :meth:`setpos`. In addition +the following methods exist. The :meth:`get\*` methods can only be called after +the corresponding :meth:`set\*` methods have been called. Before the first +:meth:`writeframes` or :meth:`writeframesraw`, all parameters except for the +number of frames must be filled in. + + +.. method:: aifc.aiff() + + Create an AIFF file. The default is that an AIFF-C file is created, unless the + name of the file ends in ``'.aiff'`` in which case the default is an AIFF file. + + +.. method:: aifc.aifc() + + Create an AIFF-C file. The default is that an AIFF-C file is created, unless + the name of the file ends in ``'.aiff'`` in which case the default is an AIFF + file. + + +.. method:: aifc.setnchannels(nchannels) + + Specify the number of channels in the audio file. + + +.. method:: aifc.setsampwidth(width) + + Specify the size in bytes of audio samples. + + +.. method:: aifc.setframerate(rate) + + Specify the sampling frequency in frames per second. + + +.. method:: aifc.setnframes(nframes) + + Specify the number of frames that are to be written to the audio file. If this + parameter is not set, or not set correctly, the file needs to support seeking. + + +.. method:: aifc.setcomptype(type, name) + + .. index:: + single: u-LAW + single: A-LAW + single: G.722 + + Specify the compression type. If not specified, the audio data will not be + compressed. In AIFF files, compression is not possible. The name parameter + should be a human-readable description of the compression type, the type + parameter should be a four-character string. Currently the following + compression types are supported: NONE, ULAW, ALAW, G722. + + +.. method:: aifc.setparams(nchannels, sampwidth, framerate, comptype, compname) + + Set all the above parameters at once. The argument is a tuple consisting of the + various parameters. This means that it is possible to use the result of a + :meth:`getparams` call as argument to :meth:`setparams`. + + +.. method:: aifc.setmark(id, pos, name) + + Add a mark with the given id (larger than 0), and the given name at the given + position. This method can be called at any time before :meth:`close`. + + +.. method:: aifc.tell() + + Return the current write position in the output file. Useful in combination + with :meth:`setmark`. + + +.. method:: aifc.writeframes(data) + + Write data to the output file. This method can only be called after the audio + file parameters have been set. + + +.. method:: aifc.writeframesraw(data) + + Like :meth:`writeframes`, except that the header of the audio file is not + updated. + + +.. method:: aifc.close() + + Close the AIFF file. The header of the file is updated to reflect the actual + size of the audio data. After calling this method, the object can no longer be + used. + diff --git a/Doc/library/allos.rst b/Doc/library/allos.rst new file mode 100644 index 0000000..900d6d3 --- /dev/null +++ b/Doc/library/allos.rst @@ -0,0 +1,27 @@ + +.. _allos: + +********************************* +Generic Operating System Services +********************************* + +The modules described in this chapter provide interfaces to operating system +features that are available on (almost) all operating systems, such as files and +a clock. The interfaces are generally modeled after the Unix or C interfaces, +but they are available on most other systems as well. Here's an overview: + + +.. toctree:: + + os.rst + time.rst + optparse.rst + getopt.rst + logging.rst + getpass.rst + curses.rst + curses.ascii.rst + curses.panel.rst + platform.rst + errno.rst + ctypes.rst diff --git a/Doc/library/anydbm.rst b/Doc/library/anydbm.rst new file mode 100644 index 0000000..413b7de --- /dev/null +++ b/Doc/library/anydbm.rst @@ -0,0 +1,96 @@ + +:mod:`anydbm` --- Generic access to DBM-style databases +======================================================= + +.. module:: anydbm + :synopsis: Generic interface to DBM-style database modules. + + +.. index:: + module: dbhash + module: bsddb + module: gdbm + module: dbm + module: dumbdbm + +:mod:`anydbm` is a generic interface to variants of the DBM database --- +:mod:`dbhash` (requires :mod:`bsddb`), :mod:`gdbm`, or :mod:`dbm`. If none of +these modules is installed, the slow-but-simple implementation in module +:mod:`dumbdbm` will be used. + + +.. function:: open(filename[, flag[, mode]]) + + Open the database file *filename* and return a corresponding object. + + If the database file already exists, the :mod:`whichdb` module is used to + determine its type and the appropriate module is used; if it does not exist, the + first module listed above that can be imported is used. + + The optional *flag* argument can be ``'r'`` to open an existing database for + reading only, ``'w'`` to open an existing database for reading and writing, + ``'c'`` to create the database if it doesn't exist, or ``'n'``, which will + always create a new empty database. If not specified, the default value is + ``'r'``. + + The optional *mode* argument is the Unix mode of the file, used only when the + database has to be created. It defaults to octal ``0666`` (and will be modified + by the prevailing umask). + + +.. exception:: error + + A tuple containing the exceptions that can be raised by each of the supported + modules, with a unique exception also named :exc:`anydbm.error` as the first + item --- the latter is used when :exc:`anydbm.error` is raised. + +The object returned by :func:`open` supports most of the same functionality as +dictionaries; keys and their corresponding values can be stored, retrieved, and +deleted, and the :meth:`has_key` and :meth:`keys` methods are available. Keys +and values must always be strings. + +The following example records some hostnames and a corresponding title, and +then prints out the contents of the database:: + + import anydbm + + # Open database, creating it if necessary. + db = anydbm.open('cache', 'c') + + # Record some values + db['www.python.org'] = 'Python Website' + db['www.cnn.com'] = 'Cable News Network' + + # Loop through contents. Other dictionary methods + # such as .keys(), .values() also work. + for k, v in db.iteritems(): + print k, '\t', v + + # Storing a non-string key or value will raise an exception (most + # likely a TypeError). + db['www.yahoo.com'] = 4 + + # Close when done. + db.close() + + +.. seealso:: + + Module :mod:`dbhash` + BSD ``db`` database interface. + + Module :mod:`dbm` + Standard Unix database interface. + + Module :mod:`dumbdbm` + Portable implementation of the ``dbm`` interface. + + Module :mod:`gdbm` + GNU database interface, based on the ``dbm`` interface. + + Module :mod:`shelve` + General object persistence built on top of the Python ``dbm`` interface. + + Module :mod:`whichdb` + Utility module used to determine the type of an existing database. + diff --git a/Doc/library/archiving.rst b/Doc/library/archiving.rst new file mode 100644 index 0000000..7d0df5f --- /dev/null +++ b/Doc/library/archiving.rst @@ -0,0 +1,18 @@ + +.. _archiving: + +****************************** +Data Compression and Archiving +****************************** + +The modules described in this chapter support data compression with the zlib, +gzip, and bzip2 algorithms, and the creation of ZIP- and tar-format archives. + + +.. toctree:: + + zlib.rst + gzip.rst + bz2.rst + zipfile.rst + tarfile.rst diff --git a/Doc/library/array.rst b/Doc/library/array.rst new file mode 100644 index 0000000..5194edc --- /dev/null +++ b/Doc/library/array.rst @@ -0,0 +1,272 @@ + +:mod:`array` --- Efficient arrays of numeric values +=================================================== + +.. module:: array + :synopsis: Efficient arrays of uniformly typed numeric values. + + +.. index:: single: arrays + +This module defines an object type which can efficiently represent an array of +basic values: characters, integers, floating point numbers. Arrays are sequence +types and behave very much like lists, except that the type of objects stored in +them is constrained. The type is specified at object creation time by using a +:dfn:`type code`, which is a single character. The following type codes are +defined: + ++-----------+----------------+-------------------+-----------------------+ +| Type code | C Type | Python Type | Minimum size in bytes | ++===========+================+===================+=======================+ +| ``'c'`` | char | character | 1 | ++-----------+----------------+-------------------+-----------------------+ +| ``'b'`` | signed char | int | 1 | ++-----------+----------------+-------------------+-----------------------+ +| ``'B'`` | unsigned char | int | 1 | ++-----------+----------------+-------------------+-----------------------+ +| ``'u'`` | Py_UNICODE | Unicode character | 2 | ++-----------+----------------+-------------------+-----------------------+ +| ``'h'`` | signed short | int | 2 | ++-----------+----------------+-------------------+-----------------------+ +| ``'H'`` | unsigned short | int | 2 | ++-----------+----------------+-------------------+-----------------------+ +| ``'i'`` | signed int | int | 2 | ++-----------+----------------+-------------------+-----------------------+ +| ``'I'`` | unsigned int | long | 2 | ++-----------+----------------+-------------------+-----------------------+ +| ``'l'`` | signed long | int | 4 | ++-----------+----------------+-------------------+-----------------------+ +| ``'L'`` | unsigned long | long | 4 | ++-----------+----------------+-------------------+-----------------------+ +| ``'f'`` | float | float | 4 | ++-----------+----------------+-------------------+-----------------------+ +| ``'d'`` | double | float | 8 | ++-----------+----------------+-------------------+-----------------------+ + +The actual representation of values is determined by the machine architecture +(strictly speaking, by the C implementation). The actual size can be accessed +through the :attr:`itemsize` attribute. The values stored for ``'L'`` and +``'I'`` items will be represented as Python long integers when retrieved, +because Python's plain integer type cannot represent the full range of C's +unsigned (long) integers. + +The module defines the following type: + + +.. function:: array(typecode[, initializer]) + + Return a new array whose items are restricted by *typecode*, and initialized + from the optional *initializer* value, which must be a list, string, or iterable + over elements of the appropriate type. + + .. versionchanged:: 2.4 + Formerly, only lists or strings were accepted. + + If given a list or string, the initializer is passed to the new array's + :meth:`fromlist`, :meth:`fromstring`, or :meth:`fromunicode` method (see below) + to add initial items to the array. Otherwise, the iterable initializer is + passed to the :meth:`extend` method. + + +.. data:: ArrayType + + Obsolete alias for :func:`array`. + +Array objects support the ordinary sequence operations of indexing, slicing, +concatenation, and multiplication. When using slice assignment, the assigned +value must be an array object with the same type code; in all other cases, +:exc:`TypeError` is raised. Array objects also implement the buffer interface, +and may be used wherever buffer objects are supported. + +The following data items and methods are also supported: + + +.. attribute:: array.typecode + + The typecode character used to create the array. + + +.. attribute:: array.itemsize + + The length in bytes of one array item in the internal representation. + + +.. method:: array.append(x) + + Append a new item with value *x* to the end of the array. + + +.. method:: array.buffer_info() + + Return a tuple ``(address, length)`` giving the current memory address and the + length in elements of the buffer used to hold array's contents. The size of the + memory buffer in bytes can be computed as ``array.buffer_info()[1] * + array.itemsize``. This is occasionally useful when working with low-level (and + inherently unsafe) I/O interfaces that require memory addresses, such as certain + :cfunc:`ioctl` operations. The returned numbers are valid as long as the array + exists and no length-changing operations are applied to it. + + .. note:: + + When using array objects from code written in C or C++ (the only way to + effectively make use of this information), it makes more sense to use the buffer + interface supported by array objects. This method is maintained for backward + compatibility and should be avoided in new code. The buffer interface is + documented in :ref:`bufferobjects`. + + +.. method:: array.byteswap() + + "Byteswap" all items of the array. This is only supported for values which are + 1, 2, 4, or 8 bytes in size; for other types of values, :exc:`RuntimeError` is + raised. It is useful when reading data from a file written on a machine with a + different byte order. + + +.. method:: array.count(x) + + Return the number of occurrences of *x* in the array. + + +.. method:: array.extend(iterable) + + Append items from *iterable* to the end of the array. If *iterable* is another + array, it must have *exactly* the same type code; if not, :exc:`TypeError` will + be raised. If *iterable* is not an array, it must be iterable and its elements + must be the right type to be appended to the array. + + .. versionchanged:: 2.4 + Formerly, the argument could only be another array. + + +.. method:: array.fromfile(f, n) + + Read *n* items (as machine values) from the file object *f* and append them to + the end of the array. If less than *n* items are available, :exc:`EOFError` is + raised, but the items that were available are still inserted into the array. + *f* must be a real built-in file object; something else with a :meth:`read` + method won't do. + + +.. method:: array.fromlist(list) + + Append items from the list. This is equivalent to ``for x in list: + a.append(x)`` except that if there is a type error, the array is unchanged. + + +.. method:: array.fromstring(s) + + Appends items from the string, interpreting the string as an array of machine + values (as if it had been read from a file using the :meth:`fromfile` method). + + +.. method:: array.fromunicode(s) + + Extends this array with data from the given unicode string. The array must + be a type ``'u'`` array; otherwise a :exc:`ValueError` is raised. Use + ``array.fromstring(unicodestring.encode(enc))`` to append Unicode data to an + array of some other type. + + +.. method:: array.index(x) + + Return the smallest *i* such that *i* is the index of the first occurrence of + *x* in the array. + + +.. method:: array.insert(i, x) + + Insert a new item with value *x* in the array before position *i*. Negative + values are treated as being relative to the end of the array. + + +.. method:: array.pop([i]) + + Removes the item with the index *i* from the array and returns it. The optional + argument defaults to ``-1``, so that by default the last item is removed and + returned. + + +.. method:: array.read(f, n) + + .. deprecated:: 1.5.1 + Use the :meth:`fromfile` method. + + Read *n* items (as machine values) from the file object *f* and append them to + the end of the array. If less than *n* items are available, :exc:`EOFError` is + raised, but the items that were available are still inserted into the array. + *f* must be a real built-in file object; something else with a :meth:`read` + method won't do. + + +.. method:: array.remove(x) + + Remove the first occurrence of *x* from the array. + + +.. method:: array.reverse() + + Reverse the order of the items in the array. + + +.. method:: array.tofile(f) + + Write all items (as machine values) to the file object *f*. + + +.. method:: array.tolist() + + Convert the array to an ordinary list with the same items. + + +.. method:: array.tostring() + + Convert the array to an array of machine values and return the string + representation (the same sequence of bytes that would be written to a file by + the :meth:`tofile` method.) + + +.. method:: array.tounicode() + + Convert the array to a unicode string. The array must be a type ``'u'`` array; + otherwise a :exc:`ValueError` is raised. Use ``array.tostring().decode(enc)`` to + obtain a unicode string from an array of some other type. + + +.. method:: array.write(f) + + .. deprecated:: 1.5.1 + Use the :meth:`tofile` method. + + Write all items (as machine values) to the file object *f*. + +When an array object is printed or converted to a string, it is represented as +``array(typecode, initializer)``. The *initializer* is omitted if the array is +empty, otherwise it is a string if the *typecode* is ``'c'``, otherwise it is a +list of numbers. The string is guaranteed to be able to be converted back to an +array with the same type and value using :func:`eval`, so long as the +:func:`array` function has been imported using ``from array import array``. +Examples:: + + array('l') + array('c', 'hello world') + array('u', u'hello \u2641') + array('l', [1, 2, 3, 4, 5]) + array('d', [1.0, 2.0, 3.14]) + + +.. seealso:: + + Module :mod:`struct` + Packing and unpacking of heterogeneous binary data. + + Module :mod:`xdrlib` + Packing and unpacking of External Data Representation (XDR) data as used in some + remote procedure call systems. + + `The Numerical Python Manual `_ + The Numeric Python extension (NumPy) defines another array type; see + http://numpy.sourceforge.net/ for further information about Numerical Python. + (A PDF version of the NumPy manual is available at + http://numpy.sourceforge.net/numdoc/numdoc.pdf). + diff --git a/Doc/library/asynchat.rst b/Doc/library/asynchat.rst new file mode 100644 index 0000000..b651c40 --- /dev/null +++ b/Doc/library/asynchat.rst @@ -0,0 +1,284 @@ + +:mod:`asynchat` --- Asynchronous socket command/response handler +================================================================ + +.. module:: asynchat + :synopsis: Support for asynchronous command/response protocols. +.. moduleauthor:: Sam Rushing +.. sectionauthor:: Steve Holden + + +This module builds on the :mod:`asyncore` infrastructure, simplifying +asynchronous clients and servers and making it easier to handle protocols whose +elements are terminated by arbitrary strings, or are of variable length. +:mod:`asynchat` defines the abstract class :class:`async_chat` that you +subclass, providing implementations of the :meth:`collect_incoming_data` and +:meth:`found_terminator` methods. It uses the same asynchronous loop as +:mod:`asyncore`, and the two types of channel, :class:`asyncore.dispatcher` and +:class:`asynchat.async_chat`, can freely be mixed in the channel map. Typically +an :class:`asyncore.dispatcher` server channel generates new +:class:`asynchat.async_chat` channel objects as it receives incoming connection +requests. + + +.. class:: async_chat() + + This class is an abstract subclass of :class:`asyncore.dispatcher`. To make + practical use of the code you must subclass :class:`async_chat`, providing + meaningful :meth:`collect_incoming_data` and :meth:`found_terminator` methods. + The :class:`asyncore.dispatcher` methods can be used, although not all make + sense in a message/response context. + + Like :class:`asyncore.dispatcher`, :class:`async_chat` defines a set of events + that are generated by an analysis of socket conditions after a :cfunc:`select` + call. Once the polling loop has been started the :class:`async_chat` object's + methods are called by the event-processing framework with no action on the part + of the programmer. + + Unlike :class:`asyncore.dispatcher`, :class:`async_chat` allows you to define a + first-in-first-out queue (fifo) of *producers*. A producer need have only one + method, :meth:`more`, which should return data to be transmitted on the channel. + The producer indicates exhaustion (*i.e.* that it contains no more data) by + having its :meth:`more` method return the empty string. At this point the + :class:`async_chat` object removes the producer from the fifo and starts using + the next producer, if any. When the producer fifo is empty the + :meth:`handle_write` method does nothing. You use the channel object's + :meth:`set_terminator` method to describe how to recognize the end of, or an + important breakpoint in, an incoming transmission from the remote endpoint. + + To build a functioning :class:`async_chat` subclass your input methods + :meth:`collect_incoming_data` and :meth:`found_terminator` must handle the data + that the channel receives asynchronously. The methods are described below. + + +.. method:: async_chat.close_when_done() + + Pushes a ``None`` on to the producer fifo. When this producer is popped off the + fifo it causes the channel to be closed. + + +.. method:: async_chat.collect_incoming_data(data) + + Called with *data* holding an arbitrary amount of received data. The default + method, which must be overridden, raises a :exc:`NotImplementedError` exception. + + +.. method:: async_chat.discard_buffers() + + In emergencies this method will discard any data held in the input and/or output + buffers and the producer fifo. + + +.. method:: async_chat.found_terminator() + + Called when the incoming data stream matches the termination condition set by + :meth:`set_terminator`. The default method, which must be overridden, raises a + :exc:`NotImplementedError` exception. The buffered input data should be + available via an instance attribute. + + +.. method:: async_chat.get_terminator() + + Returns the current terminator for the channel. + + +.. method:: async_chat.handle_close() + + Called when the channel is closed. The default method silently closes the + channel's socket. + + +.. method:: async_chat.handle_read() + + Called when a read event fires on the channel's socket in the asynchronous loop. + The default method checks for the termination condition established by + :meth:`set_terminator`, which can be either the appearance of a particular + string in the input stream or the receipt of a particular number of characters. + When the terminator is found, :meth:`handle_read` calls the + :meth:`found_terminator` method after calling :meth:`collect_incoming_data` with + any data preceding the terminating condition. + + +.. method:: async_chat.handle_write() + + Called when the application may write data to the channel. The default method + calls the :meth:`initiate_send` method, which in turn will call + :meth:`refill_buffer` to collect data from the producer fifo associated with the + channel. + + +.. method:: async_chat.push(data) + + Creates a :class:`simple_producer` object (*see below*) containing the data and + pushes it on to the channel's ``producer_fifo`` to ensure its transmission. This + is all you need to do to have the channel write the data out to the network, + although it is possible to use your own producers in more complex schemes to + implement encryption and chunking, for example. + + +.. method:: async_chat.push_with_producer(producer) + + Takes a producer object and adds it to the producer fifo associated with the + channel. When all currently-pushed producers have been exhausted the channel + will consume this producer's data by calling its :meth:`more` method and send + the data to the remote endpoint. + + +.. method:: async_chat.readable() + + Should return ``True`` for the channel to be included in the set of channels + tested by the :cfunc:`select` loop for readability. + + +.. method:: async_chat.refill_buffer() + + Refills the output buffer by calling the :meth:`more` method of the producer at + the head of the fifo. If it is exhausted then the producer is popped off the + fifo and the next producer is activated. If the current producer is, or becomes, + ``None`` then the channel is closed. + + +.. method:: async_chat.set_terminator(term) + + Sets the terminating condition to be recognised on the channel. ``term`` may be + any of three types of value, corresponding to three different ways to handle + incoming protocol data. + + +-----------+---------------------------------------------+ + | term | Description | + +===========+=============================================+ + | *string* | Will call :meth:`found_terminator` when the | + | | string is found in the input stream | + +-----------+---------------------------------------------+ + | *integer* | Will call :meth:`found_terminator` when the | + | | indicated number of characters have been | + | | received | + +-----------+---------------------------------------------+ + | ``None`` | The channel continues to collect data | + | | forever | + +-----------+---------------------------------------------+ + + Note that any data following the terminator will be available for reading by the + channel after :meth:`found_terminator` is called. + + +.. method:: async_chat.writable() + + Should return ``True`` as long as items remain on the producer fifo, or the + channel is connected and the channel's output buffer is non-empty. + + +asynchat - Auxiliary Classes and Functions +------------------------------------------ + + +.. class:: simple_producer(data[, buffer_size=512]) + + A :class:`simple_producer` takes a chunk of data and an optional buffer size. + Repeated calls to its :meth:`more` method yield successive chunks of the data no + larger than *buffer_size*. + + +.. method:: simple_producer.more() + + Produces the next chunk of information from the producer, or returns the empty + string. + + +.. class:: fifo([list=None]) + + Each channel maintains a :class:`fifo` holding data which has been pushed by the + application but not yet popped for writing to the channel. A :class:`fifo` is a + list used to hold data and/or producers until they are required. If the *list* + argument is provided then it should contain producers or data items to be + written to the channel. + + +.. method:: fifo.is_empty() + + Returns ``True`` iff the fifo is empty. + + +.. method:: fifo.first() + + Returns the least-recently :meth:`push`\ ed item from the fifo. + + +.. method:: fifo.push(data) + + Adds the given data (which may be a string or a producer object) to the producer + fifo. + + +.. method:: fifo.pop() + + If the fifo is not empty, returns ``True, first()``, deleting the popped item. + Returns ``False, None`` for an empty fifo. + +The :mod:`asynchat` module also defines one utility function, which may be of +use in network and textual analysis operations. + + +.. function:: find_prefix_at_end(haystack, needle) + + Returns ``True`` if string *haystack* ends with any non-empty prefix of string + *needle*. + + +.. _asynchat-example: + +asynchat Example +---------------- + +The following partial example shows how HTTP requests can be read with +:class:`async_chat`. A web server might create an :class:`http_request_handler` +object for each incoming client connection. Notice that initially the channel +terminator is set to match the blank line at the end of the HTTP headers, and a +flag indicates that the headers are being read. + +Once the headers have been read, if the request is of type POST (indicating that +further data are present in the input stream) then the ``Content-Length:`` +header is used to set a numeric terminator to read the right amount of data from +the channel. + +The :meth:`handle_request` method is called once all relevant input has been +marshalled, after setting the channel terminator to ``None`` to ensure that any +extraneous data sent by the web client are ignored. :: + + class http_request_handler(asynchat.async_chat): + + def __init__(self, conn, addr, sessions, log): + asynchat.async_chat.__init__(self, conn=conn) + self.addr = addr + self.sessions = sessions + self.ibuffer = [] + self.obuffer = "" + self.set_terminator("\r\n\r\n") + self.reading_headers = True + self.handling = False + self.cgi_data = None + self.log = log + + def collect_incoming_data(self, data): + """Buffer the data""" + self.ibuffer.append(data) + + def found_terminator(self): + if self.reading_headers: + self.reading_headers = False + self.parse_headers("".join(self.ibuffer)) + self.ibuffer = [] + if self.op.upper() == "POST": + clen = self.headers.getheader("content-length") + self.set_terminator(int(clen)) + else: + self.handling = True + self.set_terminator(None) + self.handle_request() + elif not self.handling: + self.set_terminator(None) # browsers sometimes over-send + self.cgi_data = parse(self.headers, "".join(self.ibuffer)) + self.handling = True + self.ibuffer = [] + self.handle_request() + diff --git a/Doc/library/asyncore.rst b/Doc/library/asyncore.rst new file mode 100644 index 0000000..7f80dd3 --- /dev/null +++ b/Doc/library/asyncore.rst @@ -0,0 +1,269 @@ + +:mod:`asyncore` --- Asynchronous socket handler +=============================================== + +.. module:: asyncore + :synopsis: A base class for developing asynchronous socket handling services. +.. moduleauthor:: Sam Rushing +.. sectionauthor:: Christopher Petrilli +.. sectionauthor:: Steve Holden + + +This module provides the basic infrastructure for writing asynchronous socket +service clients and servers. + +.. % Heavily adapted from original documentation by Sam Rushing. + +There are only two ways to have a program on a single processor do "more than +one thing at a time." Multi-threaded programming is the simplest and most +popular way to do it, but there is another very different technique, that lets +you have nearly all the advantages of multi-threading, without actually using +multiple threads. It's really only practical if your program is largely I/O +bound. If your program is processor bound, then pre-emptive scheduled threads +are probably what you really need. Network servers are rarely processor bound, +however. + +If your operating system supports the :cfunc:`select` system call in its I/O +library (and nearly all do), then you can use it to juggle multiple +communication channels at once; doing other work while your I/O is taking place +in the "background." Although this strategy can seem strange and complex, +especially at first, it is in many ways easier to understand and control than +multi-threaded programming. The :mod:`asyncore` module solves many of the +difficult problems for you, making the task of building sophisticated +high-performance network servers and clients a snap. For "conversational" +applications and protocols the companion :mod:`asynchat` module is invaluable. + +The basic idea behind both modules is to create one or more network *channels*, +instances of class :class:`asyncore.dispatcher` and +:class:`asynchat.async_chat`. Creating the channels adds them to a global map, +used by the :func:`loop` function if you do not provide it with your own *map*. + +Once the initial channel(s) is(are) created, calling the :func:`loop` function +activates channel service, which continues until the last channel (including any +that have been added to the map during asynchronous service) is closed. + + +.. function:: loop([timeout[, use_poll[, map[,count]]]]) + + Enter a polling loop that terminates after count passes or all open channels + have been closed. All arguments are optional. The *count* parameter defaults + to None, resulting in the loop terminating only when all channels have been + closed. The *timeout* argument sets the timeout parameter for the appropriate + :func:`select` or :func:`poll` call, measured in seconds; the default is 30 + seconds. The *use_poll* parameter, if true, indicates that :func:`poll` should + be used in preference to :func:`select` (the default is ``False``). + + The *map* parameter is a dictionary whose items are the channels to watch. As + channels are closed they are deleted from their map. If *map* is omitted, a + global map is used. Channels (instances of :class:`asyncore.dispatcher`, + :class:`asynchat.async_chat` and subclasses thereof) can freely be mixed in the + map. + + +.. class:: dispatcher() + + The :class:`dispatcher` class is a thin wrapper around a low-level socket + object. To make it more useful, it has a few methods for event-handling which + are called from the asynchronous loop. Otherwise, it can be treated as a + normal non-blocking socket object. + + Two class attributes can be modified, to improve performance, or possibly even + to conserve memory. + + + .. data:: ac_in_buffer_size + + The asynchronous input buffer size (default ``4096``). + + + .. data:: ac_out_buffer_size + + The asynchronous output buffer size (default ``4096``). + + The firing of low-level events at certain times or in certain connection states + tells the asynchronous loop that certain higher-level events have taken place. + For example, if we have asked for a socket to connect to another host, we know + that the connection has been made when the socket becomes writable for the first + time (at this point you know that you may write to it with the expectation of + success). The implied higher-level events are: + + +----------------------+----------------------------------------+ + | Event | Description | + +======================+========================================+ + | ``handle_connect()`` | Implied by the first write event | + +----------------------+----------------------------------------+ + | ``handle_close()`` | Implied by a read event with no data | + | | available | + +----------------------+----------------------------------------+ + | ``handle_accept()`` | Implied by a read event on a listening | + | | socket | + +----------------------+----------------------------------------+ + + During asynchronous processing, each mapped channel's :meth:`readable` and + :meth:`writable` methods are used to determine whether the channel's socket + should be added to the list of channels :cfunc:`select`\ ed or :cfunc:`poll`\ ed + for read and write events. + +Thus, the set of channel events is larger than the basic socket events. The full +set of methods that can be overridden in your subclass follows: + + +.. method:: dispatcher.handle_read() + + Called when the asynchronous loop detects that a :meth:`read` call on the + channel's socket will succeed. + + +.. method:: dispatcher.handle_write() + + Called when the asynchronous loop detects that a writable socket can be written. + Often this method will implement the necessary buffering for performance. For + example:: + + def handle_write(self): + sent = self.send(self.buffer) + self.buffer = self.buffer[sent:] + + +.. method:: dispatcher.handle_expt() + + Called when there is out of band (OOB) data for a socket connection. This will + almost never happen, as OOB is tenuously supported and rarely used. + + +.. method:: dispatcher.handle_connect() + + Called when the active opener's socket actually makes a connection. Might send a + "welcome" banner, or initiate a protocol negotiation with the remote endpoint, + for example. + + +.. method:: dispatcher.handle_close() + + Called when the socket is closed. + + +.. method:: dispatcher.handle_error() + + Called when an exception is raised and not otherwise handled. The default + version prints a condensed traceback. + + +.. method:: dispatcher.handle_accept() + + Called on listening channels (passive openers) when a connection can be + established with a new remote endpoint that has issued a :meth:`connect` call + for the local endpoint. + + +.. method:: dispatcher.readable() + + Called each time around the asynchronous loop to determine whether a channel's + socket should be added to the list on which read events can occur. The default + method simply returns ``True``, indicating that by default, all channels will + be interested in read events. + + +.. method:: dispatcher.writable() + + Called each time around the asynchronous loop to determine whether a channel's + socket should be added to the list on which write events can occur. The default + method simply returns ``True``, indicating that by default, all channels will + be interested in write events. + +In addition, each channel delegates or extends many of the socket methods. Most +of these are nearly identical to their socket partners. + + +.. method:: dispatcher.create_socket(family, type) + + This is identical to the creation of a normal socket, and will use the same + options for creation. Refer to the :mod:`socket` documentation for information + on creating sockets. + + +.. method:: dispatcher.connect(address) + + As with the normal socket object, *address* is a tuple with the first element + the host to connect to, and the second the port number. + + +.. method:: dispatcher.send(data) + + Send *data* to the remote end-point of the socket. + + +.. method:: dispatcher.recv(buffer_size) + + Read at most *buffer_size* bytes from the socket's remote end-point. An empty + string implies that the channel has been closed from the other end. + + +.. method:: dispatcher.listen(backlog) + + Listen for connections made to the socket. The *backlog* argument specifies the + maximum number of queued connections and should be at least 1; the maximum value + is system-dependent (usually 5). + + +.. method:: dispatcher.bind(address) + + Bind the socket to *address*. The socket must not already be bound. (The + format of *address* depends on the address family --- see above.) To mark the + socket as re-usable (setting the :const:`SO_REUSEADDR` option), call the + :class:`dispatcher` object's :meth:`set_reuse_addr` method. + + +.. method:: dispatcher.accept() + + Accept a connection. The socket must be bound to an address and listening for + connections. The return value is a pair ``(conn, address)`` where *conn* is a + *new* socket object usable to send and receive data on the connection, and + *address* is the address bound to the socket on the other end of the connection. + + +.. method:: dispatcher.close() + + Close the socket. All future operations on the socket object will fail. The + remote end-point will receive no more data (after queued data is flushed). + Sockets are automatically closed when they are garbage-collected. + + +.. _asyncore-example: + +asyncore Example basic HTTP client +---------------------------------- + +Here is a very basic HTTP client that uses the :class:`dispatcher` class to +implement its socket handling:: + + import asyncore, socket + + class http_client(asyncore.dispatcher): + + def __init__(self, host, path): + asyncore.dispatcher.__init__(self) + self.create_socket(socket.AF_INET, socket.SOCK_STREAM) + self.connect( (host, 80) ) + self.buffer = 'GET %s HTTP/1.0\r\n\r\n' % path + + def handle_connect(self): + pass + + def handle_close(self): + self.close() + + def handle_read(self): + print self.recv(8192) + + def writable(self): + return (len(self.buffer) > 0) + + def handle_write(self): + sent = self.send(self.buffer) + self.buffer = self.buffer[sent:] + + c = http_client('www.python.org', '/') + + asyncore.loop() + diff --git a/Doc/library/atexit.rst b/Doc/library/atexit.rst new file mode 100644 index 0000000..94d750b --- /dev/null +++ b/Doc/library/atexit.rst @@ -0,0 +1,105 @@ + +:mod:`atexit` --- Exit handlers +=============================== + +.. module:: atexit + :synopsis: Register and execute cleanup functions. +.. moduleauthor:: Skip Montanaro +.. sectionauthor:: Skip Montanaro + + +.. versionadded:: 2.0 + +The :mod:`atexit` module defines functions to register and unregister cleanup +functions. Functions thus registered are automatically executed upon normal +interpreter termination. + +Note: the functions registered via this module are not called when the program +is killed by a signal, when a Python fatal internal error is detected, or when +:func:`os._exit` is called. + + +.. function:: register(func[, *args[, **kargs]]) + + Register *func* as a function to be executed at termination. Any optional + arguments that are to be passed to *func* must be passed as arguments to + :func:`register`. + + At normal program termination (for instance, if :func:`sys.exit` is called or + the main module's execution completes), all functions registered are called in + last in, first out order. The assumption is that lower level modules will + normally be imported before higher level modules and thus must be cleaned up + later. + + If an exception is raised during execution of the exit handlers, a traceback is + printed (unless :exc:`SystemExit` is raised) and the exception information is + saved. After all exit handlers have had a chance to run the last exception to + be raised is re-raised. + + .. versionchanged:: 2.6 + This function now returns *func* which makes it possible to use it as a + decorator without binding the original name to ``None``. + + +.. function:: unregister(func) + + Remove a function *func* from the list of functions to be run at interpreter- + shutdown. After calling :func:`unregister`, *func* is guaranteed not to be + called when the interpreter shuts down. + + .. versionadded:: 3.0 + + +.. seealso:: + + Module :mod:`readline` + Useful example of :mod:`atexit` to read and write :mod:`readline` history files. + + +.. _atexit-example: + +:mod:`atexit` Example +--------------------- + +The following simple example demonstrates how a module can initialize a counter +from a file when it is imported and save the counter's updated value +automatically when the program terminates without relying on the application +making an explicit call into this module at termination. :: + + try: + _count = int(open("/tmp/counter").read()) + except IOError: + _count = 0 + + def incrcounter(n): + global _count + _count = _count + n + + def savecounter(): + open("/tmp/counter", "w").write("%d" % _count) + + import atexit + atexit.register(savecounter) + +Positional and keyword arguments may also be passed to :func:`register` to be +passed along to the registered function when it is called:: + + def goodbye(name, adjective): + print 'Goodbye, %s, it was %s to meet you.' % (name, adjective) + + import atexit + atexit.register(goodbye, 'Donny', 'nice') + + # or: + atexit.register(goodbye, adjective='nice', name='Donny') + +Usage as a decorator:: + + import atexit + + @atexit.register + def goodbye(): + print "You are now leaving the Python sector." + +This obviously only works with functions that don't take arguments. + diff --git a/Doc/library/audioop.rst b/Doc/library/audioop.rst new file mode 100644 index 0000000..84a2690 --- /dev/null +++ b/Doc/library/audioop.rst @@ -0,0 +1,261 @@ + +:mod:`audioop` --- Manipulate raw audio data +============================================ + +.. module:: audioop + :synopsis: Manipulate raw audio data. + + +The :mod:`audioop` module contains some useful operations on sound fragments. +It operates on sound fragments consisting of signed integer samples 8, 16 or 32 +bits wide, stored in Python strings. All scalar items are integers, unless +specified otherwise. + +.. index:: + single: Intel/DVI ADPCM + single: ADPCM, Intel/DVI + single: a-LAW + single: u-LAW + +This module provides support for a-LAW, u-LAW and Intel/DVI ADPCM encodings. + +.. % This para is mostly here to provide an excuse for the index entries... + +A few of the more complicated operations only take 16-bit samples, otherwise the +sample size (in bytes) is always a parameter of the operation. + +The module defines the following variables and functions: + + +.. exception:: error + + This exception is raised on all errors, such as unknown number of bytes per + sample, etc. + + +.. function:: add(fragment1, fragment2, width) + + Return a fragment which is the addition of the two samples passed as parameters. + *width* is the sample width in bytes, either ``1``, ``2`` or ``4``. Both + fragments should have the same length. + + +.. function:: adpcm2lin(adpcmfragment, width, state) + + Decode an Intel/DVI ADPCM coded fragment to a linear fragment. See the + description of :func:`lin2adpcm` for details on ADPCM coding. Return a tuple + ``(sample, newstate)`` where the sample has the width specified in *width*. + + +.. function:: alaw2lin(fragment, width) + + Convert sound fragments in a-LAW encoding to linearly encoded sound fragments. + a-LAW encoding always uses 8 bits samples, so *width* refers only to the sample + width of the output fragment here. + + .. versionadded:: 2.5 + + +.. function:: avg(fragment, width) + + Return the average over all samples in the fragment. + + +.. function:: avgpp(fragment, width) + + Return the average peak-peak value over all samples in the fragment. No + filtering is done, so the usefulness of this routine is questionable. + + +.. function:: bias(fragment, width, bias) + + Return a fragment that is the original fragment with a bias added to each + sample. + + +.. function:: cross(fragment, width) + + Return the number of zero crossings in the fragment passed as an argument. + + +.. function:: findfactor(fragment, reference) + + Return a factor *F* such that ``rms(add(fragment, mul(reference, -F)))`` is + minimal, i.e., return the factor with which you should multiply *reference* to + make it match as well as possible to *fragment*. The fragments should both + contain 2-byte samples. + + The time taken by this routine is proportional to ``len(fragment)``. + + +.. function:: findfit(fragment, reference) + + Try to match *reference* as well as possible to a portion of *fragment* (which + should be the longer fragment). This is (conceptually) done by taking slices + out of *fragment*, using :func:`findfactor` to compute the best match, and + minimizing the result. The fragments should both contain 2-byte samples. + Return a tuple ``(offset, factor)`` where *offset* is the (integer) offset into + *fragment* where the optimal match started and *factor* is the (floating-point) + factor as per :func:`findfactor`. + + +.. function:: findmax(fragment, length) + + Search *fragment* for a slice of length *length* samples (not bytes!) with + maximum energy, i.e., return *i* for which ``rms(fragment[i*2:(i+length)*2])`` + is maximal. The fragments should both contain 2-byte samples. + + The routine takes time proportional to ``len(fragment)``. + + +.. function:: getsample(fragment, width, index) + + Return the value of sample *index* from the fragment. + + +.. function:: lin2adpcm(fragment, width, state) + + Convert samples to 4 bit Intel/DVI ADPCM encoding. ADPCM coding is an adaptive + coding scheme, whereby each 4 bit number is the difference between one sample + and the next, divided by a (varying) step. The Intel/DVI ADPCM algorithm has + been selected for use by the IMA, so it may well become a standard. + + *state* is a tuple containing the state of the coder. The coder returns a tuple + ``(adpcmfrag, newstate)``, and the *newstate* should be passed to the next call + of :func:`lin2adpcm`. In the initial call, ``None`` can be passed as the state. + *adpcmfrag* is the ADPCM coded fragment packed 2 4-bit values per byte. + + +.. function:: lin2alaw(fragment, width) + + Convert samples in the audio fragment to a-LAW encoding and return this as a + Python string. a-LAW is an audio encoding format whereby you get a dynamic + range of about 13 bits using only 8 bit samples. It is used by the Sun audio + hardware, among others. + + .. versionadded:: 2.5 + + +.. function:: lin2lin(fragment, width, newwidth) + + Convert samples between 1-, 2- and 4-byte formats. + + +.. function:: lin2ulaw(fragment, width) + + Convert samples in the audio fragment to u-LAW encoding and return this as a + Python string. u-LAW is an audio encoding format whereby you get a dynamic + range of about 14 bits using only 8 bit samples. It is used by the Sun audio + hardware, among others. + + +.. function:: minmax(fragment, width) + + Return a tuple consisting of the minimum and maximum values of all samples in + the sound fragment. + + +.. function:: max(fragment, width) + + Return the maximum of the *absolute value* of all samples in a fragment. + + +.. function:: maxpp(fragment, width) + + Return the maximum peak-peak value in the sound fragment. + + +.. function:: mul(fragment, width, factor) + + Return a fragment that has all samples in the original fragment multiplied by + the floating-point value *factor*. Overflow is silently ignored. + + +.. function:: ratecv(fragment, width, nchannels, inrate, outrate, state[, weightA[, weightB]]) + + Convert the frame rate of the input fragment. + + *state* is a tuple containing the state of the converter. The converter returns + a tuple ``(newfragment, newstate)``, and *newstate* should be passed to the next + call of :func:`ratecv`. The initial call should pass ``None`` as the state. + + The *weightA* and *weightB* arguments are parameters for a simple digital filter + and default to ``1`` and ``0`` respectively. + + +.. function:: reverse(fragment, width) + + Reverse the samples in a fragment and returns the modified fragment. + + +.. function:: rms(fragment, width) + + Return the root-mean-square of the fragment, i.e. ``sqrt(sum(S_i^2)/n)``. + + This is a measure of the power in an audio signal. + + +.. function:: tomono(fragment, width, lfactor, rfactor) + + Convert a stereo fragment to a mono fragment. The left channel is multiplied by + *lfactor* and the right channel by *rfactor* before adding the two channels to + give a mono signal. + + +.. function:: tostereo(fragment, width, lfactor, rfactor) + + Generate a stereo fragment from a mono fragment. Each pair of samples in the + stereo fragment are computed from the mono sample, whereby left channel samples + are multiplied by *lfactor* and right channel samples by *rfactor*. + + +.. function:: ulaw2lin(fragment, width) + + Convert sound fragments in u-LAW encoding to linearly encoded sound fragments. + u-LAW encoding always uses 8 bits samples, so *width* refers only to the sample + width of the output fragment here. + +Note that operations such as :func:`mul` or :func:`max` make no distinction +between mono and stereo fragments, i.e. all samples are treated equal. If this +is a problem the stereo fragment should be split into two mono fragments first +and recombined later. Here is an example of how to do that:: + + def mul_stereo(sample, width, lfactor, rfactor): + lsample = audioop.tomono(sample, width, 1, 0) + rsample = audioop.tomono(sample, width, 0, 1) + lsample = audioop.mul(sample, width, lfactor) + rsample = audioop.mul(sample, width, rfactor) + lsample = audioop.tostereo(lsample, width, 1, 0) + rsample = audioop.tostereo(rsample, width, 0, 1) + return audioop.add(lsample, rsample, width) + +If you use the ADPCM coder to build network packets and you want your protocol +to be stateless (i.e. to be able to tolerate packet loss) you should not only +transmit the data but also the state. Note that you should send the *initial* +state (the one you passed to :func:`lin2adpcm`) along to the decoder, not the +final state (as returned by the coder). If you want to use +:func:`struct.struct` to store the state in binary you can code the first +element (the predicted value) in 16 bits and the second (the delta index) in 8. + +The ADPCM coders have never been tried against other ADPCM coders, only against +themselves. It could well be that I misinterpreted the standards in which case +they will not be interoperable with the respective standards. + +The :func:`find\*` routines might look a bit funny at first sight. They are +primarily meant to do echo cancellation. A reasonably fast way to do this is to +pick the most energetic piece of the output sample, locate that in the input +sample and subtract the whole output sample from the input sample:: + + def echocancel(outputdata, inputdata): + pos = audioop.findmax(outputdata, 800) # one tenth second + out_test = outputdata[pos*2:] + in_test = inputdata[pos*2:] + ipos, factor = audioop.findfit(in_test, out_test) + # Optional (for better cancellation): + # factor = audioop.findfactor(in_test[ipos*2:ipos*2+len(out_test)], + # out_test) + prefill = '\0'*(pos+ipos)*2 + postfill = '\0'*(len(inputdata)-len(prefill)-len(outputdata)) + outputdata = prefill + audioop.mul(outputdata,2,-factor) + postfill + return audioop.add(inputdata, outputdata, 2) + diff --git a/Doc/library/autogil.rst b/Doc/library/autogil.rst new file mode 100644 index 0000000..93f0d04 --- /dev/null +++ b/Doc/library/autogil.rst @@ -0,0 +1,30 @@ + +:mod:`autoGIL` --- Global Interpreter Lock handling in event loops +================================================================== + +.. module:: autoGIL + :platform: Mac + :synopsis: Global Interpreter Lock handling in event loops. +.. moduleauthor:: Just van Rossum + + +The :mod:`autoGIL` module provides a function :func:`installAutoGIL` that +automatically locks and unlocks Python's Global Interpreter Lock when running an +event loop. + + +.. exception:: AutoGILError + + Raised if the observer callback cannot be installed, for example because the + current thread does not have a run loop. + + +.. function:: installAutoGIL() + + Install an observer callback in the event loop (CFRunLoop) for the current + thread, that will lock and unlock the Global Interpreter Lock (GIL) at + appropriate times, allowing other Python threads to run while the event loop is + idle. + + Availability: OSX 10.1 or later. + diff --git a/Doc/library/base64.rst b/Doc/library/base64.rst new file mode 100644 index 0000000..daa8fd5 --- /dev/null +++ b/Doc/library/base64.rst @@ -0,0 +1,172 @@ + +:mod:`base64` --- RFC 3548: Base16, Base32, Base64 Data Encodings +================================================================= + +.. module:: base64 + :synopsis: RFC 3548: Base16, Base32, Base64 Data Encodings + + +.. index:: + pair: base64; encoding + single: MIME; base64 encoding + +This module provides data encoding and decoding as specified in :rfc:`3548`. +This standard defines the Base16, Base32, and Base64 algorithms for encoding and +decoding arbitrary binary strings into text strings that can be safely sent by +email, used as parts of URLs, or included as part of an HTTP POST request. The +encoding algorithm is not the same as the :program:`uuencode` program. + +There are two interfaces provided by this module. The modern interface supports +encoding and decoding string objects using all three alphabets. The legacy +interface provides for encoding and decoding to and from file-like objects as +well as strings, but only using the Base64 standard alphabet. + +The modern interface, which was introduced in Python 2.4, provides: + + +.. function:: b64encode(s[, altchars]) + + Encode a string use Base64. + + *s* is the string to encode. Optional *altchars* must be a string of at least + length 2 (additional characters are ignored) which specifies an alternative + alphabet for the ``+`` and ``/`` characters. This allows an application to e.g. + generate URL or filesystem safe Base64 strings. The default is ``None``, for + which the standard Base64 alphabet is used. + + The encoded string is returned. + + +.. function:: b64decode(s[, altchars]) + + Decode a Base64 encoded string. + + *s* is the string to decode. Optional *altchars* must be a string of at least + length 2 (additional characters are ignored) which specifies the alternative + alphabet used instead of the ``+`` and ``/`` characters. + + The decoded string is returned. A :exc:`TypeError` is raised if *s* were + incorrectly padded or if there are non-alphabet characters present in the + string. + + +.. function:: standard_b64encode(s) + + Encode string *s* using the standard Base64 alphabet. + + +.. function:: standard_b64decode(s) + + Decode string *s* using the standard Base64 alphabet. + + +.. function:: urlsafe_b64encode(s) + + Encode string *s* using a URL-safe alphabet, which substitutes ``-`` instead of + ``+`` and ``_`` instead of ``/`` in the standard Base64 alphabet. + + +.. function:: urlsafe_b64decode(s) + + Decode string *s* using a URL-safe alphabet, which substitutes ``-`` instead of + ``+`` and ``_`` instead of ``/`` in the standard Base64 alphabet. + + +.. function:: b32encode(s) + + Encode a string using Base32. *s* is the string to encode. The encoded string + is returned. + + +.. function:: b32decode(s[, casefold[, map01]]) + + Decode a Base32 encoded string. + + *s* is the string to decode. Optional *casefold* is a flag specifying whether a + lowercase alphabet is acceptable as input. For security purposes, the default + is ``False``. + + :rfc:`3548` allows for optional mapping of the digit 0 (zero) to the letter O + (oh), and for optional mapping of the digit 1 (one) to either the letter I (eye) + or letter L (el). The optional argument *map01* when not ``None``, specifies + which letter the digit 1 should be mapped to (when *map01* is not ``None``, the + digit 0 is always mapped to the letter O). For security purposes the default is + ``None``, so that 0 and 1 are not allowed in the input. + + The decoded string is returned. A :exc:`TypeError` is raised if *s* were + incorrectly padded or if there are non-alphabet characters present in the + string. + + +.. function:: b16encode(s) + + Encode a string using Base16. + + *s* is the string to encode. The encoded string is returned. + + +.. function:: b16decode(s[, casefold]) + + Decode a Base16 encoded string. + + *s* is the string to decode. Optional *casefold* is a flag specifying whether a + lowercase alphabet is acceptable as input. For security purposes, the default + is ``False``. + + The decoded string is returned. A :exc:`TypeError` is raised if *s* were + incorrectly padded or if there are non-alphabet characters present in the + string. + +The legacy interface: + + +.. function:: decode(input, output) + + Decode the contents of the *input* file and write the resulting binary data to + the *output* file. *input* and *output* must either be file objects or objects + that mimic the file object interface. *input* will be read until + ``input.read()`` returns an empty string. + + +.. function:: decodestring(s) + + Decode the string *s*, which must contain one or more lines of base64 encoded + data, and return a string containing the resulting binary data. + + +.. function:: encode(input, output) + + Encode the contents of the *input* file and write the resulting base64 encoded + data to the *output* file. *input* and *output* must either be file objects or + objects that mimic the file object interface. *input* will be read until + ``input.read()`` returns an empty string. :func:`encode` returns the encoded + data plus a trailing newline character (``'\n'``). + + +.. function:: encodestring(s) + + Encode the string *s*, which can contain arbitrary binary data, and return a + string containing one or more lines of base64-encoded data. + :func:`encodestring` returns a string containing one or more lines of + base64-encoded data always including an extra trailing newline (``'\n'``). + +An example usage of the module:: + + >>> import base64 + >>> encoded = base64.b64encode('data to be encoded') + >>> encoded + 'ZGF0YSB0byBiZSBlbmNvZGVk' + >>> data = base64.b64decode(encoded) + >>> data + 'data to be encoded' + + +.. seealso:: + + Module :mod:`binascii` + Support module containing ASCII-to-binary and binary-to-ASCII conversions. + + :rfc:`1521` - MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies + Section 5.2, "Base64 Content-Transfer-Encoding," provides the definition of the + base64 encoding. + diff --git a/Doc/library/basehttpserver.rst b/Doc/library/basehttpserver.rst new file mode 100644 index 0000000..2e8d6a3 --- /dev/null +++ b/Doc/library/basehttpserver.rst @@ -0,0 +1,254 @@ + +:mod:`BaseHTTPServer` --- Basic HTTP server +=========================================== + +.. module:: BaseHTTPServer + :synopsis: Basic HTTP server (base class for SimpleHTTPServer and CGIHTTPServer). + + +.. index:: + pair: WWW; server + pair: HTTP; protocol + single: URL + single: httpd + +.. index:: + module: SimpleHTTPServer + module: CGIHTTPServer + +This module defines two classes for implementing HTTP servers (Web servers). +Usually, this module isn't used directly, but is used as a basis for building +functioning Web servers. See the :mod:`SimpleHTTPServer` and +:mod:`CGIHTTPServer` modules. + +The first class, :class:`HTTPServer`, is a :class:`SocketServer.TCPServer` +subclass. It creates and listens at the HTTP socket, dispatching the requests +to a handler. Code to create and run the server looks like this:: + + def run(server_class=BaseHTTPServer.HTTPServer, + handler_class=BaseHTTPServer.BaseHTTPRequestHandler): + server_address = ('', 8000) + httpd = server_class(server_address, handler_class) + httpd.serve_forever() + + +.. class:: HTTPServer(server_address, RequestHandlerClass) + + This class builds on the :class:`TCPServer` class by storing the server address + as instance variables named :attr:`server_name` and :attr:`server_port`. The + server is accessible by the handler, typically through the handler's + :attr:`server` instance variable. + + +.. class:: BaseHTTPRequestHandler(request, client_address, server) + + This class is used to handle the HTTP requests that arrive at the server. By + itself, it cannot respond to any actual HTTP requests; it must be subclassed to + handle each request method (e.g. GET or POST). :class:`BaseHTTPRequestHandler` + provides a number of class and instance variables, and methods for use by + subclasses. + + The handler will parse the request and the headers, then call a method specific + to the request type. The method name is constructed from the request. For + example, for the request method ``SPAM``, the :meth:`do_SPAM` method will be + called with no arguments. All of the relevant information is stored in instance + variables of the handler. Subclasses should not need to override or extend the + :meth:`__init__` method. + +:class:`BaseHTTPRequestHandler` has the following instance variables: + + +.. attribute:: BaseHTTPRequestHandler.client_address + + Contains a tuple of the form ``(host, port)`` referring to the client's address. + + +.. attribute:: BaseHTTPRequestHandler.command + + Contains the command (request type). For example, ``'GET'``. + + +.. attribute:: BaseHTTPRequestHandler.path + + Contains the request path. + + +.. attribute:: BaseHTTPRequestHandler.request_version + + Contains the version string from the request. For example, ``'HTTP/1.0'``. + + +.. attribute:: BaseHTTPRequestHandler.headers + + Holds an instance of the class specified by the :attr:`MessageClass` class + variable. This instance parses and manages the headers in the HTTP request. + + +.. attribute:: BaseHTTPRequestHandler.rfile + + Contains an input stream, positioned at the start of the optional input data. + + +.. attribute:: BaseHTTPRequestHandler.wfile + + Contains the output stream for writing a response back to the client. Proper + adherence to the HTTP protocol must be used when writing to this stream. + +:class:`BaseHTTPRequestHandler` has the following class variables: + + +.. attribute:: BaseHTTPRequestHandler.server_version + + Specifies the server software version. You may want to override this. The + format is multiple whitespace-separated strings, where each string is of the + form name[/version]. For example, ``'BaseHTTP/0.2'``. + + +.. attribute:: BaseHTTPRequestHandler.sys_version + + Contains the Python system version, in a form usable by the + :attr:`version_string` method and the :attr:`server_version` class variable. For + example, ``'Python/1.4'``. + + +.. attribute:: BaseHTTPRequestHandler.error_message_format + + Specifies a format string for building an error response to the client. It uses + parenthesized, keyed format specifiers, so the format operand must be a + dictionary. The *code* key should be an integer, specifying the numeric HTTP + error code value. *message* should be a string containing a (detailed) error + message of what occurred, and *explain* should be an explanation of the error + code number. Default *message* and *explain* values can found in the *responses* + class variable. + + +.. attribute:: BaseHTTPRequestHandler.protocol_version + + This specifies the HTTP protocol version used in responses. If set to + ``'HTTP/1.1'``, the server will permit HTTP persistent connections; however, + your server *must* then include an accurate ``Content-Length`` header (using + :meth:`send_header`) in all of its responses to clients. For backwards + compatibility, the setting defaults to ``'HTTP/1.0'``. + + +.. attribute:: BaseHTTPRequestHandler.MessageClass + + .. index:: single: Message (in module mimetools) + + Specifies a :class:`rfc822.Message`\ -like class to parse HTTP headers. + Typically, this is not overridden, and it defaults to + :class:`mimetools.Message`. + + +.. attribute:: BaseHTTPRequestHandler.responses + + This variable contains a mapping of error code integers to two-element tuples + containing a short and long message. For example, ``{code: (shortmessage, + longmessage)}``. The *shortmessage* is usually used as the *message* key in an + error response, and *longmessage* as the *explain* key (see the + :attr:`error_message_format` class variable). + +A :class:`BaseHTTPRequestHandler` instance has the following methods: + + +.. method:: BaseHTTPRequestHandler.handle() + + Calls :meth:`handle_one_request` once (or, if persistent connections are + enabled, multiple times) to handle incoming HTTP requests. You should never need + to override it; instead, implement appropriate :meth:`do_\*` methods. + + +.. method:: BaseHTTPRequestHandler.handle_one_request() + + This method will parse and dispatch the request to the appropriate :meth:`do_\*` + method. You should never need to override it. + + +.. method:: BaseHTTPRequestHandler.send_error(code[, message]) + + Sends and logs a complete error reply to the client. The numeric *code* + specifies the HTTP error code, with *message* as optional, more specific text. A + complete set of headers is sent, followed by text composed using the + :attr:`error_message_format` class variable. + + +.. method:: BaseHTTPRequestHandler.send_response(code[, message]) + + Sends a response header and logs the accepted request. The HTTP response line is + sent, followed by *Server* and *Date* headers. The values for these two headers + are picked up from the :meth:`version_string` and :meth:`date_time_string` + methods, respectively. + + +.. method:: BaseHTTPRequestHandler.send_header(keyword, value) + + Writes a specific HTTP header to the output stream. *keyword* should specify the + header keyword, with *value* specifying its value. + + +.. method:: BaseHTTPRequestHandler.end_headers() + + Sends a blank line, indicating the end of the HTTP headers in the response. + + +.. method:: BaseHTTPRequestHandler.log_request([code[, size]]) + + Logs an accepted (successful) request. *code* should specify the numeric HTTP + code associated with the response. If a size of the response is available, then + it should be passed as the *size* parameter. + + +.. method:: BaseHTTPRequestHandler.log_error(...) + + Logs an error when a request cannot be fulfilled. By default, it passes the + message to :meth:`log_message`, so it takes the same arguments (*format* and + additional values). + + +.. method:: BaseHTTPRequestHandler.log_message(format, ...) + + Logs an arbitrary message to ``sys.stderr``. This is typically overridden to + create custom error logging mechanisms. The *format* argument is a standard + printf-style format string, where the additional arguments to + :meth:`log_message` are applied as inputs to the formatting. The client address + and current date and time are prefixed to every message logged. + + +.. method:: BaseHTTPRequestHandler.version_string() + + Returns the server software's version string. This is a combination of the + :attr:`server_version` and :attr:`sys_version` class variables. + + +.. method:: BaseHTTPRequestHandler.date_time_string([timestamp]) + + Returns the date and time given by *timestamp* (which must be in the format + returned by :func:`time.time`), formatted for a message header. If *timestamp* + is omitted, it uses the current date and time. + + The result looks like ``'Sun, 06 Nov 1994 08:49:37 GMT'``. + + .. versionadded:: 2.5 + The *timestamp* parameter. + + +.. method:: BaseHTTPRequestHandler.log_date_time_string() + + Returns the current date and time, formatted for logging. + + +.. method:: BaseHTTPRequestHandler.address_string() + + Returns the client address, formatted for logging. A name lookup is performed on + the client's IP address. + + +.. seealso:: + + Module :mod:`CGIHTTPServer` + Extended request handler that supports CGI scripts. + + Module :mod:`SimpleHTTPServer` + Basic request handler that limits response to files actually under the document + root. + diff --git a/Doc/library/binascii.rst b/Doc/library/binascii.rst new file mode 100644 index 0000000..ffea232 --- /dev/null +++ b/Doc/library/binascii.rst @@ -0,0 +1,161 @@ + +:mod:`binascii` --- Convert between binary and ASCII +==================================================== + +.. module:: binascii + :synopsis: Tools for converting between binary and various ASCII-encoded binary + representations. + + +.. index:: + module: uu + module: base64 + module: binhex + +The :mod:`binascii` module contains a number of methods to convert between +binary and various ASCII-encoded binary representations. Normally, you will not +use these functions directly but use wrapper modules like :mod:`uu`, +:mod:`base64`, or :mod:`binhex` instead. The :mod:`binascii` module contains +low-level functions written in C for greater speed that are used by the +higher-level modules. + +The :mod:`binascii` module defines the following functions: + + +.. function:: a2b_uu(string) + + Convert a single line of uuencoded data back to binary and return the binary + data. Lines normally contain 45 (binary) bytes, except for the last line. Line + data may be followed by whitespace. + + +.. function:: b2a_uu(data) + + Convert binary data to a line of ASCII characters, the return value is the + converted line, including a newline char. The length of *data* should be at most + 45. + + +.. function:: a2b_base64(string) + + Convert a block of base64 data back to binary and return the binary data. More + than one line may be passed at a time. + + +.. function:: b2a_base64(data) + + Convert binary data to a line of ASCII characters in base64 coding. The return + value is the converted line, including a newline char. The length of *data* + should be at most 57 to adhere to the base64 standard. + + +.. function:: a2b_qp(string[, header]) + + Convert a block of quoted-printable data back to binary and return the binary + data. More than one line may be passed at a time. If the optional argument + *header* is present and true, underscores will be decoded as spaces. + + +.. function:: b2a_qp(data[, quotetabs, istext, header]) + + Convert binary data to a line(s) of ASCII characters in quoted-printable + encoding. The return value is the converted line(s). If the optional argument + *quotetabs* is present and true, all tabs and spaces will be encoded. If the + optional argument *istext* is present and true, newlines are not encoded but + trailing whitespace will be encoded. If the optional argument *header* is + present and true, spaces will be encoded as underscores per RFC1522. If the + optional argument *header* is present and false, newline characters will be + encoded as well; otherwise linefeed conversion might corrupt the binary data + stream. + + +.. function:: a2b_hqx(string) + + Convert binhex4 formatted ASCII data to binary, without doing RLE-decompression. + The string should contain a complete number of binary bytes, or (in case of the + last portion of the binhex4 data) have the remaining bits zero. + + +.. function:: rledecode_hqx(data) + + Perform RLE-decompression on the data, as per the binhex4 standard. The + algorithm uses ``0x90`` after a byte as a repeat indicator, followed by a count. + A count of ``0`` specifies a byte value of ``0x90``. The routine returns the + decompressed data, unless data input data ends in an orphaned repeat indicator, + in which case the :exc:`Incomplete` exception is raised. + + +.. function:: rlecode_hqx(data) + + Perform binhex4 style RLE-compression on *data* and return the result. + + +.. function:: b2a_hqx(data) + + Perform hexbin4 binary-to-ASCII translation and return the resulting string. The + argument should already be RLE-coded, and have a length divisible by 3 (except + possibly the last fragment). + + +.. function:: crc_hqx(data, crc) + + Compute the binhex4 crc value of *data*, starting with an initial *crc* and + returning the result. + + +.. function:: crc32(data[, crc]) + + Compute CRC-32, the 32-bit checksum of data, starting with an initial crc. This + is consistent with the ZIP file checksum. Since the algorithm is designed for + use as a checksum algorithm, it is not suitable for use as a general hash + algorithm. Use as follows:: + + print binascii.crc32("hello world") + # Or, in two pieces: + crc = binascii.crc32("hello") + crc = binascii.crc32(" world", crc) + print crc + + +.. function:: b2a_hex(data) + hexlify(data) + + Return the hexadecimal representation of the binary *data*. Every byte of + *data* is converted into the corresponding 2-digit hex representation. The + resulting string is therefore twice as long as the length of *data*. + + +.. function:: a2b_hex(hexstr) + unhexlify(hexstr) + + Return the binary data represented by the hexadecimal string *hexstr*. This + function is the inverse of :func:`b2a_hex`. *hexstr* must contain an even number + of hexadecimal digits (which can be upper or lower case), otherwise a + :exc:`TypeError` is raised. + + +.. exception:: Error + + Exception raised on errors. These are usually programming errors. + + +.. exception:: Incomplete + + Exception raised on incomplete data. These are usually not programming errors, + but may be handled by reading a little more data and trying again. + + +.. seealso:: + + Module :mod:`base64` + Support for base64 encoding used in MIME email messages. + + Module :mod:`binhex` + Support for the binhex format used on the Macintosh. + + Module :mod:`uu` + Support for UU encoding used on Unix. + + Module :mod:`quopri` + Support for quoted-printable encoding used in MIME email messages. + diff --git a/Doc/library/binhex.rst b/Doc/library/binhex.rst new file mode 100644 index 0000000..3b0485c --- /dev/null +++ b/Doc/library/binhex.rst @@ -0,0 +1,59 @@ + +:mod:`binhex` --- Encode and decode binhex4 files +================================================= + +.. module:: binhex + :synopsis: Encode and decode files in binhex4 format. + + +This module encodes and decodes files in binhex4 format, a format allowing +representation of Macintosh files in ASCII. On the Macintosh, both forks of a +file and the finder information are encoded (or decoded), on other platforms +only the data fork is handled. + +The :mod:`binhex` module defines the following functions: + + +.. function:: binhex(input, output) + + Convert a binary file with filename *input* to binhex file *output*. The + *output* parameter can either be a filename or a file-like object (any object + supporting a :meth:`write` and :meth:`close` method). + + +.. function:: hexbin(input[, output]) + + Decode a binhex file *input*. *input* may be a filename or a file-like object + supporting :meth:`read` and :meth:`close` methods. The resulting file is written + to a file named *output*, unless the argument is omitted in which case the + output filename is read from the binhex file. + +The following exception is also defined: + + +.. exception:: Error + + Exception raised when something can't be encoded using the binhex format (for + example, a filename is too long to fit in the filename field), or when input is + not properly encoded binhex data. + + +.. seealso:: + + Module :mod:`binascii` + Support module containing ASCII-to-binary and binary-to-ASCII conversions. + + +.. _binhex-notes: + +Notes +----- + +There is an alternative, more powerful interface to the coder and decoder, see +the source for details. + +If you code or decode textfiles on non-Macintosh platforms they will still use +the Macintosh newline convention (carriage-return as end of line). + +As of this writing, :func:`hexbin` appears to not work in all cases. + diff --git a/Doc/library/bisect.rst b/Doc/library/bisect.rst new file mode 100644 index 0000000..b8eb348 --- /dev/null +++ b/Doc/library/bisect.rst @@ -0,0 +1,92 @@ + +:mod:`bisect` --- Array bisection algorithm +=========================================== + +.. module:: bisect + :synopsis: Array bisection algorithms for binary searching. +.. sectionauthor:: Fred L. Drake, Jr. + + +.. % LaTeX produced by Fred L. Drake, Jr. , with an +.. % example based on the PyModules FAQ entry by Aaron Watters +.. % . + +This module provides support for maintaining a list in sorted order without +having to sort the list after each insertion. For long lists of items with +expensive comparison operations, this can be an improvement over the more common +approach. The module is called :mod:`bisect` because it uses a basic bisection +algorithm to do its work. The source code may be most useful as a working +example of the algorithm (the boundary conditions are already right!). + +The following functions are provided: + + +.. function:: bisect_left(list, item[, lo[, hi]]) + + Locate the proper insertion point for *item* in *list* to maintain sorted order. + The parameters *lo* and *hi* may be used to specify a subset of the list which + should be considered; by default the entire list is used. If *item* is already + present in *list*, the insertion point will be before (to the left of) any + existing entries. The return value is suitable for use as the first parameter + to ``list.insert()``. This assumes that *list* is already sorted. + + .. versionadded:: 2.1 + + +.. function:: bisect_right(list, item[, lo[, hi]]) + + Similar to :func:`bisect_left`, but returns an insertion point which comes after + (to the right of) any existing entries of *item* in *list*. + + .. versionadded:: 2.1 + + +.. function:: bisect(...) + + Alias for :func:`bisect_right`. + + +.. function:: insort_left(list, item[, lo[, hi]]) + + Insert *item* in *list* in sorted order. This is equivalent to + ``list.insert(bisect.bisect_left(list, item, lo, hi), item)``. This assumes + that *list* is already sorted. + + .. versionadded:: 2.1 + + +.. function:: insort_right(list, item[, lo[, hi]]) + + Similar to :func:`insort_left`, but inserting *item* in *list* after any + existing entries of *item*. + + .. versionadded:: 2.1 + + +.. function:: insort(...) + + Alias for :func:`insort_right`. + + +Examples +-------- + +.. _bisect-example: + +The :func:`bisect` function is generally useful for categorizing numeric data. +This example uses :func:`bisect` to look up a letter grade for an exam total +(say) based on a set of ordered numeric breakpoints: 85 and up is an 'A', 75..84 +is a 'B', etc. :: + + >>> grades = "FEDCBA" + >>> breakpoints = [30, 44, 66, 75, 85] + >>> from bisect import bisect + >>> def grade(total): + ... return grades[bisect(breakpoints, total)] + ... + >>> grade(66) + 'C' + >>> map(grade, [33, 99, 77, 44, 12, 88]) + ['E', 'A', 'B', 'D', 'F', 'A'] + + diff --git a/Doc/library/bsddb.rst b/Doc/library/bsddb.rst new file mode 100644 index 0000000..55b7c7d --- /dev/null +++ b/Doc/library/bsddb.rst @@ -0,0 +1,211 @@ + +:mod:`bsddb` --- Interface to Berkeley DB library +================================================= + +.. module:: bsddb + :synopsis: Interface to Berkeley DB database library +.. sectionauthor:: Skip Montanaro + + +The :mod:`bsddb` module provides an interface to the Berkeley DB library. Users +can create hash, btree or record based library files using the appropriate open +call. Bsddb objects behave generally like dictionaries. Keys and values must be +strings, however, so to use other objects as keys or to store other kinds of +objects the user must serialize them somehow, typically using +:func:`marshal.dumps` or :func:`pickle.dumps`. + +The :mod:`bsddb` module requires a Berkeley DB library version from 3.3 thru +4.5. + + +.. seealso:: + + http://pybsddb.sourceforge.net/ + The website with documentation for the :mod:`bsddb.db` Python Berkeley DB + interface that closely mirrors the object oriented interface provided in + Berkeley DB 3 and 4. + + http://www.oracle.com/database/berkeley-db/ + The Berkeley DB library. + +A more modern DB, DBEnv and DBSequence object interface is available in the +:mod:`bsddb.db` module which closely matches the Berkeley DB C API documented at +the above URLs. Additional features provided by the :mod:`bsddb.db` API include +fine tuning, transactions, logging, and multiprocess concurrent database access. + +The following is a description of the legacy :mod:`bsddb` interface compatible +with the old Python bsddb module. Starting in Python 2.5 this interface should +be safe for multithreaded access. The :mod:`bsddb.db` API is recommended for +threading users as it provides better control. + +The :mod:`bsddb` module defines the following functions that create objects that +access the appropriate type of Berkeley DB file. The first two arguments of +each function are the same. For ease of portability, only the first two +arguments should be used in most instances. + + +.. function:: hashopen(filename[, flag[, mode[, pgsize[, ffactor[, nelem[, cachesize[, lorder[, hflags]]]]]]]]) + + Open the hash format file named *filename*. Files never intended to be + preserved on disk may be created by passing ``None`` as the *filename*. The + optional *flag* identifies the mode used to open the file. It may be ``'r'`` + (read only), ``'w'`` (read-write) , ``'c'`` (read-write - create if necessary; + the default) or ``'n'`` (read-write - truncate to zero length). The other + arguments are rarely used and are just passed to the low-level :cfunc:`dbopen` + function. Consult the Berkeley DB documentation for their use and + interpretation. + + +.. function:: btopen(filename[, flag[, mode[, btflags[, cachesize[, maxkeypage[, minkeypage[, pgsize[, lorder]]]]]]]]) + + Open the btree format file named *filename*. Files never intended to be + preserved on disk may be created by passing ``None`` as the *filename*. The + optional *flag* identifies the mode used to open the file. It may be ``'r'`` + (read only), ``'w'`` (read-write), ``'c'`` (read-write - create if necessary; + the default) or ``'n'`` (read-write - truncate to zero length). The other + arguments are rarely used and are just passed to the low-level dbopen function. + Consult the Berkeley DB documentation for their use and interpretation. + + +.. function:: rnopen(filename[, flag[, mode[, rnflags[, cachesize[, pgsize[, lorder[, rlen[, delim[, source[, pad]]]]]]]]]]) + + Open a DB record format file named *filename*. Files never intended to be + preserved on disk may be created by passing ``None`` as the *filename*. The + optional *flag* identifies the mode used to open the file. It may be ``'r'`` + (read only), ``'w'`` (read-write), ``'c'`` (read-write - create if necessary; + the default) or ``'n'`` (read-write - truncate to zero length). The other + arguments are rarely used and are just passed to the low-level dbopen function. + Consult the Berkeley DB documentation for their use and interpretation. + + +.. class:: StringKeys(db) + + Wrapper class around a DB object that supports string keys (rather than bytes). + All keys are encoded as UTF-8, then passed to the underlying object. + + .. versionadded:: 3.0 + + +.. class:: StringValues(db) + + Wrapper class around a DB object that supports string values (rather than bytes). + All values are encoded as UTF-8, then passed to the underlying object. + + .. versionadded:: 3.0 + + +.. seealso:: + + Module :mod:`dbhash` + DBM-style interface to the :mod:`bsddb` + + +.. _bsddb-objects: + +Hash, BTree and Record Objects +------------------------------ + +Once instantiated, hash, btree and record objects support the same methods as +dictionaries. In addition, they support the methods listed below. + +.. versionchanged:: 2.3.1 + Added dictionary methods. + + +.. method:: bsddbobject.close() + + Close the underlying file. The object can no longer be accessed. Since there + is no open :meth:`open` method for these objects, to open the file again a new + :mod:`bsddb` module open function must be called. + + +.. method:: bsddbobject.keys() + + Return the list of keys contained in the DB file. The order of the list is + unspecified and should not be relied on. In particular, the order of the list + returned is different for different file formats. + + +.. method:: bsddbobject.has_key(key) + + Return ``1`` if the DB file contains the argument as a key. + + +.. method:: bsddbobject.set_location(key) + + Set the cursor to the item indicated by *key* and return a tuple containing the + key and its value. For binary tree databases (opened using :func:`btopen`), if + *key* does not actually exist in the database, the cursor will point to the next + item in sorted order and return that key and value. For other databases, + :exc:`KeyError` will be raised if *key* is not found in the database. + + +.. method:: bsddbobject.first() + + Set the cursor to the first item in the DB file and return it. The order of + keys in the file is unspecified, except in the case of B-Tree databases. This + method raises :exc:`bsddb.error` if the database is empty. + + +.. method:: bsddbobject.next() + + Set the cursor to the next item in the DB file and return it. The order of + keys in the file is unspecified, except in the case of B-Tree databases. + + +.. method:: bsddbobject.previous() + + Set the cursor to the previous item in the DB file and return it. The order of + keys in the file is unspecified, except in the case of B-Tree databases. This + is not supported on hashtable databases (those opened with :func:`hashopen`). + + +.. method:: bsddbobject.last() + + Set the cursor to the last item in the DB file and return it. The order of keys + in the file is unspecified. This is not supported on hashtable databases (those + opened with :func:`hashopen`). This method raises :exc:`bsddb.error` if the + database is empty. + + +.. method:: bsddbobject.sync() + + Synchronize the database on disk. + +Example:: + + >>> import bsddb + >>> db = bsddb.btopen('/tmp/spam.db', 'c') + >>> for i in range(10): db['%d'%i] = '%d'% (i*i) + ... + >>> db['3'] + '9' + >>> db.keys() + ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'] + >>> db.first() + ('0', '0') + >>> db.next() + ('1', '1') + >>> db.last() + ('9', '81') + >>> db.set_location('2') + ('2', '4') + >>> db.previous() + ('1', '1') + >>> for k, v in db.iteritems(): + ... print k, v + 0 0 + 1 1 + 2 4 + 3 9 + 4 16 + 5 25 + 6 36 + 7 49 + 8 64 + 9 81 + >>> '8' in db + True + >>> db.sync() + 0 + diff --git a/Doc/library/bz2.rst b/Doc/library/bz2.rst new file mode 100644 index 0000000..a8c0911 --- /dev/null +++ b/Doc/library/bz2.rst @@ -0,0 +1,181 @@ + +:mod:`bz2` --- Compression compatible with :program:`bzip2` +=========================================================== + +.. module:: bz2 + :synopsis: Interface to compression and decompression routines compatible with bzip2. +.. moduleauthor:: Gustavo Niemeyer +.. sectionauthor:: Gustavo Niemeyer + + +.. versionadded:: 2.3 + +This module provides a comprehensive interface for the bz2 compression library. +It implements a complete file interface, one-shot (de)compression functions, and +types for sequential (de)compression. + +Here is a resume of the features offered by the bz2 module: + +* :class:`BZ2File` class implements a complete file interface, including + :meth:`readline`, :meth:`readlines`, :meth:`writelines`, :meth:`seek`, etc; + +* :class:`BZ2File` class implements emulated :meth:`seek` support; + +* :class:`BZ2File` class implements universal newline support; + +* :class:`BZ2File` class offers an optimized line iteration using the readahead + algorithm borrowed from file objects; + +* Sequential (de)compression supported by :class:`BZ2Compressor` and + :class:`BZ2Decompressor` classes; + +* One-shot (de)compression supported by :func:`compress` and :func:`decompress` + functions; + +* Thread safety uses individual locking mechanism; + +* Complete inline documentation; + + +(De)compression of files +------------------------ + +Handling of compressed files is offered by the :class:`BZ2File` class. + + +.. class:: BZ2File(filename[, mode[, buffering[, compresslevel]]]) + + Open a bz2 file. Mode can be either ``'r'`` or ``'w'``, for reading (default) + or writing. When opened for writing, the file will be created if it doesn't + exist, and truncated otherwise. If *buffering* is given, ``0`` means unbuffered, + and larger numbers specify the buffer size; the default is ``0``. If + *compresslevel* is given, it must be a number between ``1`` and ``9``; the + default is ``9``. Add a ``'U'`` to mode to open the file for input with + universal newline support. Any line ending in the input file will be seen as a + ``'\n'`` in Python. Also, a file so opened gains the attribute + :attr:`newlines`; the value for this attribute is one of ``None`` (no newline + read yet), ``'\r'``, ``'\n'``, ``'\r\n'`` or a tuple containing all the newline + types seen. Universal newlines are available only when reading. Instances + support iteration in the same way as normal :class:`file` instances. + + +.. method:: BZ2File.close() + + Close the file. Sets data attribute :attr:`closed` to true. A closed file cannot + be used for further I/O operations. :meth:`close` may be called more than once + without error. + + +.. method:: BZ2File.read([size]) + + Read at most *size* uncompressed bytes, returned as a string. If the *size* + argument is negative or omitted, read until EOF is reached. + + +.. method:: BZ2File.readline([size]) + + Return the next line from the file, as a string, retaining newline. A + non-negative *size* argument limits the maximum number of bytes to return (an + incomplete line may be returned then). Return an empty string at EOF. + + +.. method:: BZ2File.readlines([size]) + + Return a list of lines read. The optional *size* argument, if given, is an + approximate bound on the total number of bytes in the lines returned. + + +.. method:: BZ2File.seek(offset[, whence]) + + Move to new file position. Argument *offset* is a byte count. Optional argument + *whence* defaults to ``os.SEEK_SET`` or ``0`` (offset from start of file; offset + should be ``>= 0``); other values are ``os.SEEK_CUR`` or ``1`` (move relative to + current position; offset can be positive or negative), and ``os.SEEK_END`` or + ``2`` (move relative to end of file; offset is usually negative, although many + platforms allow seeking beyond the end of a file). + + Note that seeking of bz2 files is emulated, and depending on the parameters the + operation may be extremely slow. + + +.. method:: BZ2File.tell() + + Return the current file position, an integer (may be a long integer). + + +.. method:: BZ2File.write(data) + + Write string *data* to file. Note that due to buffering, :meth:`close` may be + needed before the file on disk reflects the data written. + + +.. method:: BZ2File.writelines(sequence_of_strings) + + Write the sequence of strings to the file. Note that newlines are not added. The + sequence can be any iterable object producing strings. This is equivalent to + calling write() for each string. + + +Sequential (de)compression +-------------------------- + +Sequential compression and decompression is done using the classes +:class:`BZ2Compressor` and :class:`BZ2Decompressor`. + + +.. class:: BZ2Compressor([compresslevel]) + + Create a new compressor object. This object may be used to compress data + sequentially. If you want to compress data in one shot, use the :func:`compress` + function instead. The *compresslevel* parameter, if given, must be a number + between ``1`` and ``9``; the default is ``9``. + + +.. method:: BZ2Compressor.compress(data) + + Provide more data to the compressor object. It will return chunks of compressed + data whenever possible. When you've finished providing data to compress, call + the :meth:`flush` method to finish the compression process, and return what is + left in internal buffers. + + +.. method:: BZ2Compressor.flush() + + Finish the compression process and return what is left in internal buffers. You + must not use the compressor object after calling this method. + + +.. class:: BZ2Decompressor() + + Create a new decompressor object. This object may be used to decompress data + sequentially. If you want to decompress data in one shot, use the + :func:`decompress` function instead. + + +.. method:: BZ2Decompressor.decompress(data) + + Provide more data to the decompressor object. It will return chunks of + decompressed data whenever possible. If you try to decompress data after the end + of stream is found, :exc:`EOFError` will be raised. If any data was found after + the end of stream, it'll be ignored and saved in :attr:`unused_data` attribute. + + +One-shot (de)compression +------------------------ + +One-shot compression and decompression is provided through the :func:`compress` +and :func:`decompress` functions. + + +.. function:: compress(data[, compresslevel]) + + Compress *data* in one shot. If you want to compress data sequentially, use an + instance of :class:`BZ2Compressor` instead. The *compresslevel* parameter, if + given, must be a number between ``1`` and ``9``; the default is ``9``. + + +.. function:: decompress(data) + + Decompress *data* in one shot. If you want to decompress data sequentially, use + an instance of :class:`BZ2Decompressor` instead. + diff --git a/Doc/library/calendar.rst b/Doc/library/calendar.rst new file mode 100644 index 0000000..68cbeb6 --- /dev/null +++ b/Doc/library/calendar.rst @@ -0,0 +1,326 @@ + +:mod:`calendar` --- General calendar-related functions +====================================================== + +.. module:: calendar + :synopsis: Functions for working with calendars, including some emulation of the Unix cal + program. +.. sectionauthor:: Drew Csillag + + +This module allows you to output calendars like the Unix :program:`cal` program, +and provides additional useful functions related to the calendar. By default, +these calendars have Monday as the first day of the week, and Sunday as the last +(the European convention). Use :func:`setfirstweekday` to set the first day of +the week to Sunday (6) or to any other weekday. Parameters that specify dates +are given as integers. For related +functionality, see also the :mod:`datetime` and :mod:`time` modules. + +Most of these functions and classses rely on the :mod:`datetime` module which +uses an idealized calendar, the current Gregorian calendar indefinitely extended +in both directions. This matches the definition of the "proleptic Gregorian" +calendar in Dershowitz and Reingold's book "Calendrical Calculations", where +it's the base calendar for all computations. + + +.. class:: Calendar([firstweekday]) + + Creates a :class:`Calendar` object. *firstweekday* is an integer specifying the + first day of the week. ``0`` is Monday (the default), ``6`` is Sunday. + + A :class:`Calendar` object provides several methods that can be used for + preparing the calendar data for formatting. This class doesn't do any formatting + itself. This is the job of subclasses. + + .. versionadded:: 2.5 + +:class:`Calendar` instances have the following methods: + + +.. method:: Calendar.iterweekdays(weekday) + + Return an iterator for the week day numbers that will be used for one week. The + first number from the iterator will be the same as the number returned by + :meth:`firstweekday`. + + +.. method:: Calendar.itermonthdates(year, month) + + Return an iterator for the month *month* (1-12) in the year *year*. This + iterator will return all days (as :class:`datetime.date` objects) for the month + and all days before the start of the month or after the end of the month that + are required to get a complete week. + + +.. method:: Calendar.itermonthdays2(year, month) + + Return an iterator for the month *month* in the year *year* similar to + :meth:`itermonthdates`. Days returned will be tuples consisting of a day number + and a week day number. + + +.. method:: Calendar.itermonthdays(year, month) + + Return an iterator for the month *month* in the year *year* similar to + :meth:`itermonthdates`. Days returned will simply be day numbers. + + +.. method:: Calendar.monthdatescalendar(year, month) + + Return a list of the weeks in the month *month* of the *year* as full weeks. + Weeks are lists of seven :class:`datetime.date` objects. + + +.. method:: Calendar.monthdays2calendar(year, month) + + Return a list of the weeks in the month *month* of the *year* as full weeks. + Weeks are lists of seven tuples of day numbers and weekday numbers. + + +.. method:: Calendar.monthdayscalendar(year, month) + + Return a list of the weeks in the month *month* of the *year* as full weeks. + Weeks are lists of seven day numbers. + + +.. method:: Calendar.yeardatescalendar(year, month[, width]) + + Return the data for the specified year ready for formatting. The return value is + a list of month rows. Each month row contains up to *width* months (defaulting + to 3). Each month contains between 4 and 6 weeks and each week contains 1--7 + days. Days are :class:`datetime.date` objects. + + +.. method:: Calendar.yeardays2calendar(year, month[, width]) + + Return the data for the specified year ready for formatting (similar to + :meth:`yeardatescalendar`). Entries in the week lists are tuples of day numbers + and weekday numbers. Day numbers outside this month are zero. + + +.. method:: Calendar.yeardayscalendar(year, month[, width]) + + Return the data for the specified year ready for formatting (similar to + :meth:`yeardatescalendar`). Entries in the week lists are day numbers. Day + numbers outside this month are zero. + + +.. class:: TextCalendar([firstweekday]) + + This class can be used to generate plain text calendars. + + .. versionadded:: 2.5 + +:class:`TextCalendar` instances have the following methods: + + +.. method:: TextCalendar.formatmonth(theyear, themonth[, w[, l]]) + + Return a month's calendar in a multi-line string. If *w* is provided, it + specifies the width of the date columns, which are centered. If *l* is given, it + specifies the number of lines that each week will use. Depends on the first + weekday as set by :func:`setfirstweekday`. + + +.. method:: TextCalendar.prmonth(theyear, themonth[, w[, l]]) + + Print a month's calendar as returned by :meth:`formatmonth`. + + +.. method:: TextCalendar.formatyear(theyear, themonth[, w[, l[, c[, m]]]]) + + Return a *m*-column calendar for an entire year as a multi-line string. Optional + parameters *w*, *l*, and *c* are for date column width, lines per week, and + number of spaces between month columns, respectively. Depends on the first + weekday as set by :meth:`setfirstweekday`. The earliest year for which a + calendar can be generated is platform-dependent. + + +.. method:: TextCalendar.pryear(theyear[, w[, l[, c[, m]]]]) + + Print the calendar for an entire year as returned by :meth:`formatyear`. + + +.. class:: HTMLCalendar([firstweekday]) + + This class can be used to generate HTML calendars. + + .. versionadded:: 2.5 + +:class:`HTMLCalendar` instances have the following methods: + + +.. method:: HTMLCalendar.formatmonth(theyear, themonth[, withyear]) + + Return a month's calendar as an HTML table. If *withyear* is true the year will + be included in the header, otherwise just the month name will be used. + + +.. method:: HTMLCalendar.formatyear(theyear, themonth[, width]) + + Return a year's calendar as an HTML table. *width* (defaulting to 3) specifies + the number of months per row. + + +.. method:: HTMLCalendar.formatyearpage(theyear, themonth[, width[, css[, encoding]]]) + + Return a year's calendar as a complete HTML page. *width* (defaulting to 3) + specifies the number of months per row. *css* is the name for the cascading + style sheet to be used. :const:`None` can be passed if no style sheet should be + used. *encoding* specifies the encoding to be used for the output (defaulting to + the system default encoding). + + +.. class:: LocaleTextCalendar([firstweekday[, locale]]) + + This subclass of :class:`TextCalendar` can be passed a locale name in the + constructor and will return month and weekday names in the specified locale. If + this locale includes an encoding all strings containing month and weekday names + will be returned as unicode. + + .. versionadded:: 2.5 + + +.. class:: LocaleHTMLCalendar([firstweekday[, locale]]) + + This subclass of :class:`HTMLCalendar` can be passed a locale name in the + constructor and will return month and weekday names in the specified locale. If + this locale includes an encoding all strings containing month and weekday names + will be returned as unicode. + + .. versionadded:: 2.5 + +For simple text calendars this module provides the following functions. + + +.. function:: setfirstweekday(weekday) + + Sets the weekday (``0`` is Monday, ``6`` is Sunday) to start each week. The + values :const:`MONDAY`, :const:`TUESDAY`, :const:`WEDNESDAY`, :const:`THURSDAY`, + :const:`FRIDAY`, :const:`SATURDAY`, and :const:`SUNDAY` are provided for + convenience. For example, to set the first weekday to Sunday:: + + import calendar + calendar.setfirstweekday(calendar.SUNDAY) + + .. versionadded:: 2.0 + + +.. function:: firstweekday() + + Returns the current setting for the weekday to start each week. + + .. versionadded:: 2.0 + + +.. function:: isleap(year) + + Returns :const:`True` if *year* is a leap year, otherwise :const:`False`. + + +.. function:: leapdays(y1, y2) + + Returns the number of leap years in the range from *y1* to *y2* (exclusive), + where *y1* and *y2* are years. + + .. versionchanged:: 2.0 + This function didn't work for ranges spanning a century change in Python + 1.5.2. + + +.. function:: weekday(year, month, day) + + Returns the day of the week (``0`` is Monday) for *year* (``1970``--...), + *month* (``1``--``12``), *day* (``1``--``31``). + + +.. function:: weekheader(n) + + Return a header containing abbreviated weekday names. *n* specifies the width in + characters for one weekday. + + +.. function:: monthrange(year, month) + + Returns weekday of first day of the month and number of days in month, for the + specified *year* and *month*. + + +.. function:: monthcalendar(year, month) + + Returns a matrix representing a month's calendar. Each row represents a week; + days outside of the month a represented by zeros. Each week begins with Monday + unless set by :func:`setfirstweekday`. + + +.. function:: prmonth(theyear, themonth[, w[, l]]) + + Prints a month's calendar as returned by :func:`month`. + + +.. function:: month(theyear, themonth[, w[, l]]) + + Returns a month's calendar in a multi-line string using the :meth:`formatmonth` + of the :class:`TextCalendar` class. + + .. versionadded:: 2.0 + + +.. function:: prcal(year[, w[, l[c]]]) + + Prints the calendar for an entire year as returned by :func:`calendar`. + + +.. function:: calendar(year[, w[, l[c]]]) + + Returns a 3-column calendar for an entire year as a multi-line string using the + :meth:`formatyear` of the :class:`TextCalendar` class. + + .. versionadded:: 2.0 + + +.. function:: timegm(tuple) + + An unrelated but handy function that takes a time tuple such as returned by the + :func:`gmtime` function in the :mod:`time` module, and returns the corresponding + Unix timestamp value, assuming an epoch of 1970, and the POSIX encoding. In + fact, :func:`time.gmtime` and :func:`timegm` are each others' inverse. + + .. versionadded:: 2.0 + +The :mod:`calendar` module exports the following data attributes: + + +.. data:: day_name + + An array that represents the days of the week in the current locale. + + +.. data:: day_abbr + + An array that represents the abbreviated days of the week in the current locale. + + +.. data:: month_name + + An array that represents the months of the year in the current locale. This + follows normal convention of January being month number 1, so it has a length of + 13 and ``month_name[0]`` is the empty string. + + +.. data:: month_abbr + + An array that represents the abbreviated months of the year in the current + locale. This follows normal convention of January being month number 1, so it + has a length of 13 and ``month_abbr[0]`` is the empty string. + + +.. seealso:: + + Module :mod:`datetime` + Object-oriented interface to dates and times with similar functionality to the + :mod:`time` module. + + Module :mod:`time` + Low-level time related functions. + diff --git a/Doc/library/carbon.rst b/Doc/library/carbon.rst new file mode 100644 index 0000000..ecaf3bb --- /dev/null +++ b/Doc/library/carbon.rst @@ -0,0 +1,288 @@ + +.. _toolbox: + +********************* +MacOS Toolbox Modules +********************* + +There are a set of modules that provide interfaces to various MacOS toolboxes. +If applicable the module will define a number of Python objects for the various +structures declared by the toolbox, and operations will be implemented as +methods of the object. Other operations will be implemented as functions in the +module. Not all operations possible in C will also be possible in Python +(callbacks are often a problem), and parameters will occasionally be different +in Python (input and output buffers, especially). All methods and functions +have a :attr:`__doc__` string describing their arguments and return values, and +for additional description you are referred to `Inside Macintosh +`_ or similar works. + +These modules all live in a package called :mod:`Carbon`. Despite that name they +are not all part of the Carbon framework: CF is really in the CoreFoundation +framework and Qt is in the QuickTime framework. The normal use pattern is :: + + from Carbon import AE + +**Warning!** These modules are not yet documented. If you wish to contribute +documentation of any of these modules, please get in touch with docs@python.org. + + +:mod:`Carbon.AE` --- Apple Events +================================= + +.. module:: Carbon.AE + :platform: Mac + :synopsis: Interface to the Apple Events toolbox. + + + +:mod:`Carbon.AH` --- Apple Help +=============================== + +.. module:: Carbon.AH + :platform: Mac + :synopsis: Interface to the Apple Help manager. + + + +:mod:`Carbon.App` --- Appearance Manager +======================================== + +.. module:: Carbon.App + :platform: Mac + :synopsis: Interface to the Appearance Manager. + + + +:mod:`Carbon.CF` --- Core Foundation +==================================== + +.. module:: Carbon.CF + :platform: Mac + :synopsis: Interface to the Core Foundation. + + +The ``CFBase``, ``CFArray``, ``CFData``, ``CFDictionary``, ``CFString`` and +``CFURL`` objects are supported, some only partially. + + +:mod:`Carbon.CG` --- Core Graphics +================================== + +.. module:: Carbon.CG + :platform: Mac + :synopsis: Interface to the Component Manager. + + + +:mod:`Carbon.CarbonEvt` --- Carbon Event Manager +================================================ + +.. module:: Carbon.CarbonEvt + :platform: Mac + :synopsis: Interface to the Carbon Event Manager. + + + +:mod:`Carbon.Cm` --- Component Manager +====================================== + +.. module:: Carbon.Cm + :platform: Mac + :synopsis: Interface to the Component Manager. + + + +:mod:`Carbon.Ctl` --- Control Manager +===================================== + +.. module:: Carbon.Ctl + :platform: Mac + :synopsis: Interface to the Control Manager. + + + +:mod:`Carbon.Dlg` --- Dialog Manager +==================================== + +.. module:: Carbon.Dlg + :platform: Mac + :synopsis: Interface to the Dialog Manager. + + + +:mod:`Carbon.Evt` --- Event Manager +=================================== + +.. module:: Carbon.Evt + :platform: Mac + :synopsis: Interface to the classic Event Manager. + + + +:mod:`Carbon.Fm` --- Font Manager +================================= + +.. module:: Carbon.Fm + :platform: Mac + :synopsis: Interface to the Font Manager. + + + +:mod:`Carbon.Folder` --- Folder Manager +======================================= + +.. module:: Carbon.Folder + :platform: Mac + :synopsis: Interface to the Folder Manager. + + + +:mod:`Carbon.Help` --- Help Manager +=================================== + +.. module:: Carbon.Help + :platform: Mac + :synopsis: Interface to the Carbon Help Manager. + + + +:mod:`Carbon.List` --- List Manager +=================================== + +.. module:: Carbon.List + :platform: Mac + :synopsis: Interface to the List Manager. + + + +:mod:`Carbon.Menu` --- Menu Manager +=================================== + +.. module:: Carbon.Menu + :platform: Mac + :synopsis: Interface to the Menu Manager. + + + +:mod:`Carbon.Mlte` --- MultiLingual Text Editor +=============================================== + +.. module:: Carbon.Mlte + :platform: Mac + :synopsis: Interface to the MultiLingual Text Editor. + + + +:mod:`Carbon.Qd` --- QuickDraw +============================== + +.. module:: Carbon.Qd + :platform: Mac + :synopsis: Interface to the QuickDraw toolbox. + + + +:mod:`Carbon.Qdoffs` --- QuickDraw Offscreen +============================================ + +.. module:: Carbon.Qdoffs + :platform: Mac + :synopsis: Interface to the QuickDraw Offscreen APIs. + + + +:mod:`Carbon.Qt` --- QuickTime +============================== + +.. module:: Carbon.Qt + :platform: Mac + :synopsis: Interface to the QuickTime toolbox. + + + +:mod:`Carbon.Res` --- Resource Manager and Handles +================================================== + +.. module:: Carbon.Res + :platform: Mac + :synopsis: Interface to the Resource Manager and Handles. + + + +:mod:`Carbon.Scrap` --- Scrap Manager +===================================== + +.. module:: Carbon.Scrap + :platform: Mac + :synopsis: The Scrap Manager provides basic services for implementing cut & paste and + clipboard operations. + + +This module is only fully available on MacOS9 and earlier under classic PPC +MacPython. Very limited functionality is available under Carbon MacPython. + +.. index:: single: Scrap Manager + +The Scrap Manager supports the simplest form of cut & paste operations on the +Macintosh. It can be use for both inter- and intra-application clipboard +operations. + +The :mod:`Scrap` module provides low-level access to the functions of the Scrap +Manager. It contains the following functions: + + +.. function:: InfoScrap() + + Return current information about the scrap. The information is encoded as a + tuple containing the fields ``(size, handle, count, state, path)``. + + +----------+---------------------------------------------+ + | Field | Meaning | + +==========+=============================================+ + | *size* | Size of the scrap in bytes. | + +----------+---------------------------------------------+ + | *handle* | Resource object representing the scrap. | + +----------+---------------------------------------------+ + | *count* | Serial number of the scrap contents. | + +----------+---------------------------------------------+ + | *state* | Integer; positive if in memory, ``0`` if on | + | | disk, negative if uninitialized. | + +----------+---------------------------------------------+ + | *path* | Filename of the scrap when stored on disk. | + +----------+---------------------------------------------+ + + +.. seealso:: + + `Scrap Manager `_ + Apple's documentation for the Scrap Manager gives a lot of useful information + about using the Scrap Manager in applications. + + + +:mod:`Carbon.Snd` --- Sound Manager +=================================== + +.. module:: Carbon.Snd + :platform: Mac + :synopsis: Interface to the Sound Manager. + + + +:mod:`Carbon.TE` --- TextEdit +============================= + +.. module:: Carbon.TE + :platform: Mac + :synopsis: Interface to TextEdit. + + + +:mod:`Carbon.Win` --- Window Manager +==================================== + +.. module:: Carbon.Win + :platform: Mac + :synopsis: Interface to the Window Manager. + + diff --git a/Doc/library/cgi.rst b/Doc/library/cgi.rst new file mode 100644 index 0000000..29ed545 --- /dev/null +++ b/Doc/library/cgi.rst @@ -0,0 +1,558 @@ + +:mod:`cgi` --- Common Gateway Interface support. +================================================ + +.. module:: cgi + :synopsis: Helpers for running Python scripts via the Common Gateway Interface. + + +.. index:: + pair: WWW; server + pair: CGI; protocol + pair: HTTP; protocol + pair: MIME; headers + single: URL + single: Common Gateway Interface + +Support module for Common Gateway Interface (CGI) scripts. + +This module defines a number of utilities for use by CGI scripts written in +Python. + + +Introduction +------------ + +.. _cgi-intro: + +A CGI script is invoked by an HTTP server, usually to process user input +submitted through an HTML ``
    `` or ```` element. + +Most often, CGI scripts live in the server's special :file:`cgi-bin` directory. +The HTTP server places all sorts of information about the request (such as the +client's hostname, the requested URL, the query string, and lots of other +goodies) in the script's shell environment, executes the script, and sends the +script's output back to the client. + +The script's input is connected to the client too, and sometimes the form data +is read this way; at other times the form data is passed via the "query string" +part of the URL. This module is intended to take care of the different cases +and provide a simpler interface to the Python script. It also provides a number +of utilities that help in debugging scripts, and the latest addition is support +for file uploads from a form (if your browser supports it). + +The output of a CGI script should consist of two sections, separated by a blank +line. The first section contains a number of headers, telling the client what +kind of data is following. Python code to generate a minimal header section +looks like this:: + + print "Content-Type: text/html" # HTML is following + print # blank line, end of headers + +The second section is usually HTML, which allows the client software to display +nicely formatted text with header, in-line images, etc. Here's Python code that +prints a simple piece of HTML:: + + print "CGI script output" + print "

    This is my first CGI script

    " + print "Hello, world!" + + +.. _using-the-cgi-module: + +Using the cgi module +-------------------- + +Begin by writing ``import cgi``. Do not use ``from cgi import *`` --- the +module defines all sorts of names for its own use or for backward compatibility +that you don't want in your namespace. + +When you write a new script, consider adding the line:: + + import cgitb; cgitb.enable() + +This activates a special exception handler that will display detailed reports in +the Web browser if any errors occur. If you'd rather not show the guts of your +program to users of your script, you can have the reports saved to files +instead, with a line like this:: + + import cgitb; cgitb.enable(display=0, logdir="/tmp") + +It's very helpful to use this feature during script development. The reports +produced by :mod:`cgitb` provide information that can save you a lot of time in +tracking down bugs. You can always remove the ``cgitb`` line later when you +have tested your script and are confident that it works correctly. + +To get at submitted form data, it's best to use the :class:`FieldStorage` class. +The other classes defined in this module are provided mostly for backward +compatibility. Instantiate it exactly once, without arguments. This reads the +form contents from standard input or the environment (depending on the value of +various environment variables set according to the CGI standard). Since it may +consume standard input, it should be instantiated only once. + +The :class:`FieldStorage` instance can be indexed like a Python dictionary, and +also supports the standard dictionary methods :meth:`has_key` and :meth:`keys`. +The built-in :func:`len` is also supported. Form fields containing empty +strings are ignored and do not appear in the dictionary; to keep such values, +provide a true value for the optional *keep_blank_values* keyword parameter when +creating the :class:`FieldStorage` instance. + +For instance, the following code (which assumes that the +:mailheader:`Content-Type` header and blank line have already been printed) +checks that the fields ``name`` and ``addr`` are both set to a non-empty +string:: + + form = cgi.FieldStorage() + if not (form.has_key("name") and form.has_key("addr")): + print "

    Error

    " + print "Please fill in the name and addr fields." + return + print "

    name:", form["name"].value + print "

    addr:", form["addr"].value + ...further form processing here... + +Here the fields, accessed through ``form[key]``, are themselves instances of +:class:`FieldStorage` (or :class:`MiniFieldStorage`, depending on the form +encoding). The :attr:`value` attribute of the instance yields the string value +of the field. The :meth:`getvalue` method returns this string value directly; +it also accepts an optional second argument as a default to return if the +requested key is not present. + +If the submitted form data contains more than one field with the same name, the +object retrieved by ``form[key]`` is not a :class:`FieldStorage` or +:class:`MiniFieldStorage` instance but a list of such instances. Similarly, in +this situation, ``form.getvalue(key)`` would return a list of strings. If you +expect this possibility (when your HTML form contains multiple fields with the +same name), use the :func:`getlist` function, which always returns a list of +values (so that you do not need to special-case the single item case). For +example, this code concatenates any number of username fields, separated by +commas:: + + value = form.getlist("username") + usernames = ",".join(value) + +If a field represents an uploaded file, accessing the value via the +:attr:`value` attribute or the :func:`getvalue` method reads the entire file in +memory as a string. This may not be what you want. You can test for an uploaded +file by testing either the :attr:`filename` attribute or the :attr:`file` +attribute. You can then read the data at leisure from the :attr:`file` +attribute:: + + fileitem = form["userfile"] + if fileitem.file: + # It's an uploaded file; count lines + linecount = 0 + while 1: + line = fileitem.file.readline() + if not line: break + linecount = linecount + 1 + +The file upload draft standard entertains the possibility of uploading multiple +files from one field (using a recursive :mimetype:`multipart/\*` encoding). +When this occurs, the item will be a dictionary-like :class:`FieldStorage` item. +This can be determined by testing its :attr:`type` attribute, which should be +:mimetype:`multipart/form-data` (or perhaps another MIME type matching +:mimetype:`multipart/\*`). In this case, it can be iterated over recursively +just like the top-level form object. + +When a form is submitted in the "old" format (as the query string or as a single +data part of type :mimetype:`application/x-www-form-urlencoded`), the items will +actually be instances of the class :class:`MiniFieldStorage`. In this case, the +:attr:`list`, :attr:`file`, and :attr:`filename` attributes are always ``None``. + + +Higher Level Interface +---------------------- + +.. versionadded:: 2.2 + +The previous section explains how to read CGI form data using the +:class:`FieldStorage` class. This section describes a higher level interface +which was added to this class to allow one to do it in a more readable and +intuitive way. The interface doesn't make the techniques described in previous +sections obsolete --- they are still useful to process file uploads efficiently, +for example. + +.. % XXX: Is this true ? + +The interface consists of two simple methods. Using the methods you can process +form data in a generic way, without the need to worry whether only one or more +values were posted under one name. + +In the previous section, you learned to write following code anytime you +expected a user to post more than one value under one name:: + + item = form.getvalue("item") + if isinstance(item, list): + # The user is requesting more than one item. + else: + # The user is requesting only one item. + +This situation is common for example when a form contains a group of multiple +checkboxes with the same name:: + + + + +In most situations, however, there's only one form control with a particular +name in a form and then you expect and need only one value associated with this +name. So you write a script containing for example this code:: + + user = form.getvalue("user").upper() + +The problem with the code is that you should never expect that a client will +provide valid input to your scripts. For example, if a curious user appends +another ``user=foo`` pair to the query string, then the script would crash, +because in this situation the ``getvalue("user")`` method call returns a list +instead of a string. Calling the :meth:`toupper` method on a list is not valid +(since lists do not have a method of this name) and results in an +:exc:`AttributeError` exception. + +Therefore, the appropriate way to read form data values was to always use the +code which checks whether the obtained value is a single value or a list of +values. That's annoying and leads to less readable scripts. + +A more convenient approach is to use the methods :meth:`getfirst` and +:meth:`getlist` provided by this higher level interface. + + +.. method:: FieldStorage.getfirst(name[, default]) + + This method always returns only one value associated with form field *name*. + The method returns only the first value in case that more values were posted + under such name. Please note that the order in which the values are received + may vary from browser to browser and should not be counted on. [#]_ If no such + form field or value exists then the method returns the value specified by the + optional parameter *default*. This parameter defaults to ``None`` if not + specified. + + +.. method:: FieldStorage.getlist(name) + + This method always returns a list of values associated with form field *name*. + The method returns an empty list if no such form field or value exists for + *name*. It returns a list consisting of one item if only one such value exists. + +Using these methods you can write nice compact code:: + + import cgi + form = cgi.FieldStorage() + user = form.getfirst("user", "").upper() # This way it's safe. + for item in form.getlist("item"): + do_something(item) + + +Old classes +----------- + +These classes, present in earlier versions of the :mod:`cgi` module, are still +supported for backward compatibility. New applications should use the +:class:`FieldStorage` class. + +:class:`SvFormContentDict` stores single value form content as dictionary; it +assumes each field name occurs in the form only once. + +:class:`FormContentDict` stores multiple value form content as a dictionary (the +form items are lists of values). Useful if your form contains multiple fields +with the same name. + +Other classes (:class:`FormContent`, :class:`InterpFormContentDict`) are present +for backwards compatibility with really old applications only. If you still use +these and would be inconvenienced when they disappeared from a next version of +this module, drop me a note. + + +.. _functions-in-cgi-module: + +Functions +--------- + +These are useful if you want more control, or if you want to employ some of the +algorithms implemented in this module in other circumstances. + + +.. function:: parse(fp[, keep_blank_values[, strict_parsing]]) + + Parse a query in the environment or from a file (the file defaults to + ``sys.stdin``). The *keep_blank_values* and *strict_parsing* parameters are + passed to :func:`parse_qs` unchanged. + + +.. function:: parse_qs(qs[, keep_blank_values[, strict_parsing]]) + + Parse a query string given as a string argument (data of type + :mimetype:`application/x-www-form-urlencoded`). Data are returned as a + dictionary. The dictionary keys are the unique query variable names and the + values are lists of values for each name. + + The optional argument *keep_blank_values* is a flag indicating whether blank + values in URL encoded queries should be treated as blank strings. A true value + indicates that blanks should be retained as blank strings. The default false + value indicates that blank values are to be ignored and treated as if they were + not included. + + The optional argument *strict_parsing* is a flag indicating what to do with + parsing errors. If false (the default), errors are silently ignored. If true, + errors raise a :exc:`ValueError` exception. + + Use the :func:`urllib.urlencode` function to convert such dictionaries into + query strings. + + +.. function:: parse_qsl(qs[, keep_blank_values[, strict_parsing]]) + + Parse a query string given as a string argument (data of type + :mimetype:`application/x-www-form-urlencoded`). Data are returned as a list of + name, value pairs. + + The optional argument *keep_blank_values* is a flag indicating whether blank + values in URL encoded queries should be treated as blank strings. A true value + indicates that blanks should be retained as blank strings. The default false + value indicates that blank values are to be ignored and treated as if they were + not included. + + The optional argument *strict_parsing* is a flag indicating what to do with + parsing errors. If false (the default), errors are silently ignored. If true, + errors raise a :exc:`ValueError` exception. + + Use the :func:`urllib.urlencode` function to convert such lists of pairs into + query strings. + + +.. function:: parse_multipart(fp, pdict) + + Parse input of type :mimetype:`multipart/form-data` (for file uploads). + Arguments are *fp* for the input file and *pdict* for a dictionary containing + other parameters in the :mailheader:`Content-Type` header. + + Returns a dictionary just like :func:`parse_qs` keys are the field names, each + value is a list of values for that field. This is easy to use but not much good + if you are expecting megabytes to be uploaded --- in that case, use the + :class:`FieldStorage` class instead which is much more flexible. + + Note that this does not parse nested multipart parts --- use + :class:`FieldStorage` for that. + + +.. function:: parse_header(string) + + Parse a MIME header (such as :mailheader:`Content-Type`) into a main value and a + dictionary of parameters. + + +.. function:: test() + + Robust test CGI script, usable as main program. Writes minimal HTTP headers and + formats all information provided to the script in HTML form. + + +.. function:: print_environ() + + Format the shell environment in HTML. + + +.. function:: print_form(form) + + Format a form in HTML. + + +.. function:: print_directory() + + Format the current directory in HTML. + + +.. function:: print_environ_usage() + + Print a list of useful (used by CGI) environment variables in HTML. + + +.. function:: escape(s[, quote]) + + Convert the characters ``'&'``, ``'<'`` and ``'>'`` in string *s* to HTML-safe + sequences. Use this if you need to display text that might contain such + characters in HTML. If the optional flag *quote* is true, the quotation mark + character (``'"'``) is also translated; this helps for inclusion in an HTML + attribute value, as in ````. If the value to be quoted might + include single- or double-quote characters, or both, consider using the + :func:`quoteattr` function in the :mod:`xml.sax.saxutils` module instead. + + +.. _cgi-security: + +Caring about security +--------------------- + +.. index:: pair: CGI; security + +There's one important rule: if you invoke an external program (via the +:func:`os.system` or :func:`os.popen` functions. or others with similar +functionality), make very sure you don't pass arbitrary strings received from +the client to the shell. This is a well-known security hole whereby clever +hackers anywhere on the Web can exploit a gullible CGI script to invoke +arbitrary shell commands. Even parts of the URL or field names cannot be +trusted, since the request doesn't have to come from your form! + +To be on the safe side, if you must pass a string gotten from a form to a shell +command, you should make sure the string contains only alphanumeric characters, +dashes, underscores, and periods. + + +Installing your CGI script on a Unix system +------------------------------------------- + +Read the documentation for your HTTP server and check with your local system +administrator to find the directory where CGI scripts should be installed; +usually this is in a directory :file:`cgi-bin` in the server tree. + +Make sure that your script is readable and executable by "others"; the Unix file +mode should be ``0755`` octal (use ``chmod 0755 filename``). Make sure that the +first line of the script contains ``#!`` starting in column 1 followed by the +pathname of the Python interpreter, for instance:: + + #!/usr/local/bin/python + +Make sure the Python interpreter exists and is executable by "others". + +Make sure that any files your script needs to read or write are readable or +writable, respectively, by "others" --- their mode should be ``0644`` for +readable and ``0666`` for writable. This is because, for security reasons, the +HTTP server executes your script as user "nobody", without any special +privileges. It can only read (write, execute) files that everybody can read +(write, execute). The current directory at execution time is also different (it +is usually the server's cgi-bin directory) and the set of environment variables +is also different from what you get when you log in. In particular, don't count +on the shell's search path for executables (:envvar:`PATH`) or the Python module +search path (:envvar:`PYTHONPATH`) to be set to anything interesting. + +If you need to load modules from a directory which is not on Python's default +module search path, you can change the path in your script, before importing +other modules. For example:: + + import sys + sys.path.insert(0, "/usr/home/joe/lib/python") + sys.path.insert(0, "/usr/local/lib/python") + +(This way, the directory inserted last will be searched first!) + +Instructions for non-Unix systems will vary; check your HTTP server's +documentation (it will usually have a section on CGI scripts). + + +Testing your CGI script +----------------------- + +Unfortunately, a CGI script will generally not run when you try it from the +command line, and a script that works perfectly from the command line may fail +mysteriously when run from the server. There's one reason why you should still +test your script from the command line: if it contains a syntax error, the +Python interpreter won't execute it at all, and the HTTP server will most likely +send a cryptic error to the client. + +Assuming your script has no syntax errors, yet it does not work, you have no +choice but to read the next section. + + +Debugging CGI scripts +--------------------- + +.. index:: pair: CGI; debugging + +First of all, check for trivial installation errors --- reading the section +above on installing your CGI script carefully can save you a lot of time. If +you wonder whether you have understood the installation procedure correctly, try +installing a copy of this module file (:file:`cgi.py`) as a CGI script. When +invoked as a script, the file will dump its environment and the contents of the +form in HTML form. Give it the right mode etc, and send it a request. If it's +installed in the standard :file:`cgi-bin` directory, it should be possible to +send it a request by entering a URL into your browser of the form:: + + http://yourhostname/cgi-bin/cgi.py?name=Joe+Blow&addr=At+Home + +If this gives an error of type 404, the server cannot find the script -- perhaps +you need to install it in a different directory. If it gives another error, +there's an installation problem that you should fix before trying to go any +further. If you get a nicely formatted listing of the environment and form +content (in this example, the fields should be listed as "addr" with value "At +Home" and "name" with value "Joe Blow"), the :file:`cgi.py` script has been +installed correctly. If you follow the same procedure for your own script, you +should now be able to debug it. + +The next step could be to call the :mod:`cgi` module's :func:`test` function +from your script: replace its main code with the single statement :: + + cgi.test() + +This should produce the same results as those gotten from installing the +:file:`cgi.py` file itself. + +When an ordinary Python script raises an unhandled exception (for whatever +reason: of a typo in a module name, a file that can't be opened, etc.), the +Python interpreter prints a nice traceback and exits. While the Python +interpreter will still do this when your CGI script raises an exception, most +likely the traceback will end up in one of the HTTP server's log files, or be +discarded altogether. + +Fortunately, once you have managed to get your script to execute *some* code, +you can easily send tracebacks to the Web browser using the :mod:`cgitb` module. +If you haven't done so already, just add the line:: + + import cgitb; cgitb.enable() + +to the top of your script. Then try running it again; when a problem occurs, +you should see a detailed report that will likely make apparent the cause of the +crash. + +If you suspect that there may be a problem in importing the :mod:`cgitb` module, +you can use an even more robust approach (which only uses built-in modules):: + + import sys + sys.stderr = sys.stdout + print "Content-Type: text/plain" + print + ...your code here... + +This relies on the Python interpreter to print the traceback. The content type +of the output is set to plain text, which disables all HTML processing. If your +script works, the raw HTML will be displayed by your client. If it raises an +exception, most likely after the first two lines have been printed, a traceback +will be displayed. Because no HTML interpretation is going on, the traceback +will be readable. + + +Common problems and solutions +----------------------------- + +* Most HTTP servers buffer the output from CGI scripts until the script is + completed. This means that it is not possible to display a progress report on + the client's display while the script is running. + +* Check the installation instructions above. + +* Check the HTTP server's log files. (``tail -f logfile`` in a separate window + may be useful!) + +* Always check a script for syntax errors first, by doing something like + ``python script.py``. + +* If your script does not have any syntax errors, try adding ``import cgitb; + cgitb.enable()`` to the top of the script. + +* When invoking external programs, make sure they can be found. Usually, this + means using absolute path names --- :envvar:`PATH` is usually not set to a very + useful value in a CGI script. + +* When reading or writing external files, make sure they can be read or written + by the userid under which your CGI script will be running: this is typically the + userid under which the web server is running, or some explicitly specified + userid for a web server's ``suexec`` feature. + +* Don't try to give a CGI script a set-uid mode. This doesn't work on most + systems, and is a security liability as well. + +.. rubric:: Footnotes + +.. [#] Note that some recent versions of the HTML specification do state what order the + field values should be supplied in, but knowing whether a request was + received from a conforming browser, or even from a browser at all, is tedious + and error-prone. + diff --git a/Doc/library/cgihttpserver.rst b/Doc/library/cgihttpserver.rst new file mode 100644 index 0000000..4f27627 --- /dev/null +++ b/Doc/library/cgihttpserver.rst @@ -0,0 +1,73 @@ + +:mod:`CGIHTTPServer` --- CGI-capable HTTP request handler +========================================================= + +.. module:: CGIHTTPServer + :synopsis: This module provides a request handler for HTTP servers which can run CGI + scripts. +.. sectionauthor:: Moshe Zadka + + +The :mod:`CGIHTTPServer` module defines a request-handler class, interface +compatible with :class:`BaseHTTPServer.BaseHTTPRequestHandler` and inherits +behavior from :class:`SimpleHTTPServer.SimpleHTTPRequestHandler` but can also +run CGI scripts. + +.. note:: + + This module can run CGI scripts on Unix and Windows systems; on Mac OS it will + only be able to run Python scripts within the same process as itself. + +.. note:: + + CGI scripts run by the :class:`CGIHTTPRequestHandler` class cannot execute + redirects (HTTP code 302), because code 200 (script output follows) is sent + prior to execution of the CGI script. This pre-empts the status code. + +The :mod:`CGIHTTPServer` module defines the following class: + + +.. class:: CGIHTTPRequestHandler(request, client_address, server) + + This class is used to serve either files or output of CGI scripts from the + current directory and below. Note that mapping HTTP hierarchic structure to + local directory structure is exactly as in + :class:`SimpleHTTPServer.SimpleHTTPRequestHandler`. + + The class will however, run the CGI script, instead of serving it as a file, if + it guesses it to be a CGI script. Only directory-based CGI are used --- the + other common server configuration is to treat special extensions as denoting CGI + scripts. + + The :func:`do_GET` and :func:`do_HEAD` functions are modified to run CGI scripts + and serve the output, instead of serving files, if the request leads to + somewhere below the ``cgi_directories`` path. + +The :class:`CGIHTTPRequestHandler` defines the following data member: + + +.. attribute:: CGIHTTPRequestHandler.cgi_directories + + This defaults to ``['/cgi-bin', '/htbin']`` and describes directories to treat + as containing CGI scripts. + +The :class:`CGIHTTPRequestHandler` defines the following methods: + + +.. method:: CGIHTTPRequestHandler.do_POST() + + This method serves the ``'POST'`` request type, only allowed for CGI scripts. + Error 501, "Can only POST to CGI scripts", is output when trying to POST to a + non-CGI url. + +Note that CGI scripts will be run with UID of user nobody, for security reasons. +Problems with the CGI script will be translated to error 403. + +For example usage, see the implementation of the :func:`test` function. + + +.. seealso:: + + Module :mod:`BaseHTTPServer` + Base class implementation for Web server and request handler. + diff --git a/Doc/library/cgitb.rst b/Doc/library/cgitb.rst new file mode 100644 index 0000000..327cd17 --- /dev/null +++ b/Doc/library/cgitb.rst @@ -0,0 +1,64 @@ + +:mod:`cgitb` --- Traceback manager for CGI scripts +================================================== + +.. module:: cgitb + :synopsis: Configurable traceback handler for CGI scripts. +.. moduleauthor:: Ka-Ping Yee +.. sectionauthor:: Fred L. Drake, Jr. + + +.. versionadded:: 2.2 + +.. index:: + single: CGI; exceptions + single: CGI; tracebacks + single: exceptions; in CGI scripts + single: tracebacks; in CGI scripts + +The :mod:`cgitb` module provides a special exception handler for Python scripts. +(Its name is a bit misleading. It was originally designed to display extensive +traceback information in HTML for CGI scripts. It was later generalized to also +display this information in plain text.) After this module is activated, if an +uncaught exception occurs, a detailed, formatted report will be displayed. The +report includes a traceback showing excerpts of the source code for each level, +as well as the values of the arguments and local variables to currently running +functions, to help you debug the problem. Optionally, you can save this +information to a file instead of sending it to the browser. + +To enable this feature, simply add one line to the top of your CGI script:: + + import cgitb; cgitb.enable() + +The options to the :func:`enable` function control whether the report is +displayed in the browser and whether the report is logged to a file for later +analysis. + + +.. function:: enable([display[, logdir[, context[, format]]]]) + + .. index:: single: excepthook() (in module sys) + + This function causes the :mod:`cgitb` module to take over the interpreter's + default handling for exceptions by setting the value of :attr:`sys.excepthook`. + + The optional argument *display* defaults to ``1`` and can be set to ``0`` to + suppress sending the traceback to the browser. If the argument *logdir* is + present, the traceback reports are written to files. The value of *logdir* + should be a directory where these files will be placed. The optional argument + *context* is the number of lines of context to display around the current line + of source code in the traceback; this defaults to ``5``. If the optional + argument *format* is ``"html"``, the output is formatted as HTML. Any other + value forces plain text output. The default value is ``"html"``. + + +.. function:: handler([info]) + + This function handles an exception using the default settings (that is, show a + report in the browser, but don't log to a file). This can be used when you've + caught an exception and want to report it using :mod:`cgitb`. The optional + *info* argument should be a 3-tuple containing an exception type, exception + value, and traceback object, exactly like the tuple returned by + :func:`sys.exc_info`. If the *info* argument is not supplied, the current + exception is obtained from :func:`sys.exc_info`. + diff --git a/Doc/library/chunk.rst b/Doc/library/chunk.rst new file mode 100644 index 0000000..2e1798d --- /dev/null +++ b/Doc/library/chunk.rst @@ -0,0 +1,130 @@ + +:mod:`chunk` --- Read IFF chunked data +====================================== + +.. module:: chunk + :synopsis: Module to read IFF chunks. +.. moduleauthor:: Sjoerd Mullender +.. sectionauthor:: Sjoerd Mullender + + +.. index:: + single: Audio Interchange File Format + single: AIFF + single: AIFF-C + single: Real Media File Format + single: RMFF + +This module provides an interface for reading files that use EA IFF 85 chunks. +[#]_ This format is used in at least the Audio Interchange File Format +(AIFF/AIFF-C) and the Real Media File Format (RMFF). The WAVE audio file format +is closely related and can also be read using this module. + +A chunk has the following structure: + ++---------+--------+-------------------------------+ +| Offset | Length | Contents | ++=========+========+===============================+ +| 0 | 4 | Chunk ID | ++---------+--------+-------------------------------+ +| 4 | 4 | Size of chunk in big-endian | +| | | byte order, not including the | +| | | header | ++---------+--------+-------------------------------+ +| 8 | *n* | Data bytes, where *n* is the | +| | | size given in the preceding | +| | | field | ++---------+--------+-------------------------------+ +| 8 + *n* | 0 or 1 | Pad byte needed if *n* is odd | +| | | and chunk alignment is used | ++---------+--------+-------------------------------+ + +The ID is a 4-byte string which identifies the type of chunk. + +The size field (a 32-bit value, encoded using big-endian byte order) gives the +size of the chunk data, not including the 8-byte header. + +Usually an IFF-type file consists of one or more chunks. The proposed usage of +the :class:`Chunk` class defined here is to instantiate an instance at the start +of each chunk and read from the instance until it reaches the end, after which a +new instance can be instantiated. At the end of the file, creating a new +instance will fail with a :exc:`EOFError` exception. + + +.. class:: Chunk(file[, align, bigendian, inclheader]) + + Class which represents a chunk. The *file* argument is expected to be a + file-like object. An instance of this class is specifically allowed. The + only method that is needed is :meth:`read`. If the methods :meth:`seek` and + :meth:`tell` are present and don't raise an exception, they are also used. + If these methods are present and raise an exception, they are expected to not + have altered the object. If the optional argument *align* is true, chunks + are assumed to be aligned on 2-byte boundaries. If *align* is false, no + alignment is assumed. The default value is true. If the optional argument + *bigendian* is false, the chunk size is assumed to be in little-endian order. + This is needed for WAVE audio files. The default value is true. If the + optional argument *inclheader* is true, the size given in the chunk header + includes the size of the header. The default value is false. + +A :class:`Chunk` object supports the following methods: + + +.. method:: Chunk.getname() + + Returns the name (ID) of the chunk. This is the first 4 bytes of the chunk. + + +.. method:: Chunk.getsize() + + Returns the size of the chunk. + + +.. method:: Chunk.close() + + Close and skip to the end of the chunk. This does not close the underlying + file. + +The remaining methods will raise :exc:`IOError` if called after the +:meth:`close` method has been called. + + +.. method:: Chunk.isatty() + + Returns ``False``. + + +.. method:: Chunk.seek(pos[, whence]) + + Set the chunk's current position. The *whence* argument is optional and + defaults to ``0`` (absolute file positioning); other values are ``1`` (seek + relative to the current position) and ``2`` (seek relative to the file's end). + There is no return value. If the underlying file does not allow seek, only + forward seeks are allowed. + + +.. method:: Chunk.tell() + + Return the current position into the chunk. + + +.. method:: Chunk.read([size]) + + Read at most *size* bytes from the chunk (less if the read hits the end of the + chunk before obtaining *size* bytes). If the *size* argument is negative or + omitted, read all data until the end of the chunk. The bytes are returned as a + string object. An empty string is returned when the end of the chunk is + encountered immediately. + + +.. method:: Chunk.skip() + + Skip to the end of the chunk. All further calls to :meth:`read` for the chunk + will return ``''``. If you are not interested in the contents of the chunk, + this method should be called so that the file points to the start of the next + chunk. + +.. rubric:: Footnotes + +.. [#] "EA IFF 85" Standard for Interchange Format Files, Jerry Morrison, Electronic + Arts, January 1985. + diff --git a/Doc/library/cmath.rst b/Doc/library/cmath.rst new file mode 100644 index 0000000..2bc162c --- /dev/null +++ b/Doc/library/cmath.rst @@ -0,0 +1,156 @@ + +:mod:`cmath` --- Mathematical functions for complex numbers +=========================================================== + +.. module:: cmath + :synopsis: Mathematical functions for complex numbers. + + +This module is always available. It provides access to mathematical functions +for complex numbers. The functions in this module accept integers, +floating-point numbers or complex numbers as arguments. They will also accept +any Python object that has either a :meth:`__complex__` or a :meth:`__float__` +method: these methods are used to convert the object to a complex or +floating-point number, respectively, and the function is then applied to the +result of the conversion. + +The functions are: + + +.. function:: acos(x) + + Return the arc cosine of *x*. There are two branch cuts: One extends right from + 1 along the real axis to ∞, continuous from below. The other extends left from + -1 along the real axis to -∞, continuous from above. + + +.. function:: acosh(x) + + Return the hyperbolic arc cosine of *x*. There is one branch cut, extending left + from 1 along the real axis to -∞, continuous from above. + + +.. function:: asin(x) + + Return the arc sine of *x*. This has the same branch cuts as :func:`acos`. + + +.. function:: asinh(x) + + Return the hyperbolic arc sine of *x*. There are two branch cuts, extending + left from ``±1j`` to ``±∞j``, both continuous from above. These branch cuts + should be considered a bug to be corrected in a future release. The correct + branch cuts should extend along the imaginary axis, one from ``1j`` up to + ``∞j`` and continuous from the right, and one from ``-1j`` down to ``-∞j`` + and continuous from the left. + + +.. function:: atan(x) + + Return the arc tangent of *x*. There are two branch cuts: One extends from + ``1j`` along the imaginary axis to ``∞j``, continuous from the left. The + other extends from ``-1j`` along the imaginary axis to ``-∞j``, continuous + from the left. (This should probably be changed so the upper cut becomes + continuous from the other side.) + + +.. function:: atanh(x) + + Return the hyperbolic arc tangent of *x*. There are two branch cuts: One + extends from ``1`` along the real axis to ``∞``, continuous from above. The + other extends from ``-1`` along the real axis to ``-∞``, continuous from + above. (This should probably be changed so the right cut becomes continuous + from the other side.) + + +.. function:: cos(x) + + Return the cosine of *x*. + + +.. function:: cosh(x) + + Return the hyperbolic cosine of *x*. + + +.. function:: exp(x) + + Return the exponential value ``e**x``. + + +.. function:: log(x[, base]) + + Returns the logarithm of *x* to the given *base*. If the *base* is not + specified, returns the natural logarithm of *x*. There is one branch cut, from 0 + along the negative real axis to -∞, continuous from above. + + .. versionchanged:: 2.4 + *base* argument added. + + +.. function:: log10(x) + + Return the base-10 logarithm of *x*. This has the same branch cut as + :func:`log`. + + +.. function:: sin(x) + + Return the sine of *x*. + + +.. function:: sinh(x) + + Return the hyperbolic sine of *x*. + + +.. function:: sqrt(x) + + Return the square root of *x*. This has the same branch cut as :func:`log`. + + +.. function:: tan(x) + + Return the tangent of *x*. + + +.. function:: tanh(x) + + Return the hyperbolic tangent of *x*. + +The module also defines two mathematical constants: + + +.. data:: pi + + The mathematical constant *pi*, as a float. + + +.. data:: e + + The mathematical constant *e*, as a float. + +.. index:: module: math + +Note that the selection of functions is similar, but not identical, to that in +module :mod:`math`. The reason for having two modules is that some users aren't +interested in complex numbers, and perhaps don't even know what they are. They +would rather have ``math.sqrt(-1)`` raise an exception than return a complex +number. Also note that the functions defined in :mod:`cmath` always return a +complex number, even if the answer can be expressed as a real number (in which +case the complex number has an imaginary part of zero). + +A note on branch cuts: They are curves along which the given function fails to +be continuous. They are a necessary feature of many complex functions. It is +assumed that if you need to compute with complex functions, you will understand +about branch cuts. Consult almost any (not too elementary) book on complex +variables for enlightenment. For information of the proper choice of branch +cuts for numerical purposes, a good reference should be the following: + + +.. seealso:: + + Kahan, W: Branch cuts for complex elementary functions; or, Much ado about + nothing's sign bit. In Iserles, A., and Powell, M. (eds.), The state of the art + in numerical analysis. Clarendon Press (1987) pp165-211. + diff --git a/Doc/library/cmd.rst b/Doc/library/cmd.rst new file mode 100644 index 0000000..9af08e2 --- /dev/null +++ b/Doc/library/cmd.rst @@ -0,0 +1,202 @@ + +:mod:`cmd` --- Support for line-oriented command interpreters +============================================================= + +.. module:: cmd + :synopsis: Build line-oriented command interpreters. +.. sectionauthor:: Eric S. Raymond + + +The :class:`Cmd` class provides a simple framework for writing line-oriented +command interpreters. These are often useful for test harnesses, administrative +tools, and prototypes that will later be wrapped in a more sophisticated +interface. + + +.. class:: Cmd([completekey[, stdin[, stdout]]]) + + A :class:`Cmd` instance or subclass instance is a line-oriented interpreter + framework. There is no good reason to instantiate :class:`Cmd` itself; rather, + it's useful as a superclass of an interpreter class you define yourself in order + to inherit :class:`Cmd`'s methods and encapsulate action methods. + + The optional argument *completekey* is the :mod:`readline` name of a completion + key; it defaults to :kbd:`Tab`. If *completekey* is not :const:`None` and + :mod:`readline` is available, command completion is done automatically. + + The optional arguments *stdin* and *stdout* specify the input and output file + objects that the Cmd instance or subclass instance will use for input and + output. If not specified, they will default to *sys.stdin* and *sys.stdout*. + + .. versionchanged:: 2.3 + The *stdin* and *stdout* parameters were added. + + +.. _cmd-objects: + +Cmd Objects +----------- + +A :class:`Cmd` instance has the following methods: + + +.. method:: Cmd.cmdloop([intro]) + + Repeatedly issue a prompt, accept input, parse an initial prefix off the + received input, and dispatch to action methods, passing them the remainder of + the line as argument. + + The optional argument is a banner or intro string to be issued before the first + prompt (this overrides the :attr:`intro` class member). + + If the :mod:`readline` module is loaded, input will automatically inherit + :program:`bash`\ -like history-list editing (e.g. :kbd:`Control-P` scrolls back + to the last command, :kbd:`Control-N` forward to the next one, :kbd:`Control-F` + moves the cursor to the right non-destructively, :kbd:`Control-B` moves the + cursor to the left non-destructively, etc.). + + An end-of-file on input is passed back as the string ``'EOF'``. + + An interpreter instance will recognize a command name ``foo`` if and only if it + has a method :meth:`do_foo`. As a special case, a line beginning with the + character ``'?'`` is dispatched to the method :meth:`do_help`. As another + special case, a line beginning with the character ``'!'`` is dispatched to the + method :meth:`do_shell` (if such a method is defined). + + This method will return when the :meth:`postcmd` method returns a true value. + The *stop* argument to :meth:`postcmd` is the return value from the command's + corresponding :meth:`do_\*` method. + + If completion is enabled, completing commands will be done automatically, and + completing of commands args is done by calling :meth:`complete_foo` with + arguments *text*, *line*, *begidx*, and *endidx*. *text* is the string prefix + we are attempting to match: all returned matches must begin with it. *line* is + the current input line with leading whitespace removed, *begidx* and *endidx* + are the beginning and ending indexes of the prefix text, which could be used to + provide different completion depending upon which position the argument is in. + + All subclasses of :class:`Cmd` inherit a predefined :meth:`do_help`. This + method, called with an argument ``'bar'``, invokes the corresponding method + :meth:`help_bar`. With no argument, :meth:`do_help` lists all available help + topics (that is, all commands with corresponding :meth:`help_\*` methods), and + also lists any undocumented commands. + + +.. method:: Cmd.onecmd(str) + + Interpret the argument as though it had been typed in response to the prompt. + This may be overridden, but should not normally need to be; see the + :meth:`precmd` and :meth:`postcmd` methods for useful execution hooks. The + return value is a flag indicating whether interpretation of commands by the + interpreter should stop. If there is a :meth:`do_\*` method for the command + *str*, the return value of that method is returned, otherwise the return value + from the :meth:`default` method is returned. + + +.. method:: Cmd.emptyline() + + Method called when an empty line is entered in response to the prompt. If this + method is not overridden, it repeats the last nonempty command entered. + + +.. method:: Cmd.default(line) + + Method called on an input line when the command prefix is not recognized. If + this method is not overridden, it prints an error message and returns. + + +.. method:: Cmd.completedefault(text, line, begidx, endidx) + + Method called to complete an input line when no command-specific + :meth:`complete_\*` method is available. By default, it returns an empty list. + + +.. method:: Cmd.precmd(line) + + Hook method executed just before the command line *line* is interpreted, but + after the input prompt is generated and issued. This method is a stub in + :class:`Cmd`; it exists to be overridden by subclasses. The return value is + used as the command which will be executed by the :meth:`onecmd` method; the + :meth:`precmd` implementation may re-write the command or simply return *line* + unchanged. + + +.. method:: Cmd.postcmd(stop, line) + + Hook method executed just after a command dispatch is finished. This method is + a stub in :class:`Cmd`; it exists to be overridden by subclasses. *line* is the + command line which was executed, and *stop* is a flag which indicates whether + execution will be terminated after the call to :meth:`postcmd`; this will be the + return value of the :meth:`onecmd` method. The return value of this method will + be used as the new value for the internal flag which corresponds to *stop*; + returning false will cause interpretation to continue. + + +.. method:: Cmd.preloop() + + Hook method executed once when :meth:`cmdloop` is called. This method is a stub + in :class:`Cmd`; it exists to be overridden by subclasses. + + +.. method:: Cmd.postloop() + + Hook method executed once when :meth:`cmdloop` is about to return. This method + is a stub in :class:`Cmd`; it exists to be overridden by subclasses. + +Instances of :class:`Cmd` subclasses have some public instance variables: + + +.. attribute:: Cmd.prompt + + The prompt issued to solicit input. + + +.. attribute:: Cmd.identchars + + The string of characters accepted for the command prefix. + + +.. attribute:: Cmd.lastcmd + + The last nonempty command prefix seen. + + +.. attribute:: Cmd.intro + + A string to issue as an intro or banner. May be overridden by giving the + :meth:`cmdloop` method an argument. + + +.. attribute:: Cmd.doc_header + + The header to issue if the help output has a section for documented commands. + + +.. attribute:: Cmd.misc_header + + The header to issue if the help output has a section for miscellaneous help + topics (that is, there are :meth:`help_\*` methods without corresponding + :meth:`do_\*` methods). + + +.. attribute:: Cmd.undoc_header + + The header to issue if the help output has a section for undocumented commands + (that is, there are :meth:`do_\*` methods without corresponding :meth:`help_\*` + methods). + + +.. attribute:: Cmd.ruler + + The character used to draw separator lines under the help-message headers. If + empty, no ruler line is drawn. It defaults to ``'='``. + + +.. attribute:: Cmd.use_rawinput + + A flag, defaulting to true. If true, :meth:`cmdloop` uses :func:`input` to + display a prompt and read the next command; if false, :meth:`sys.stdout.write` + and :meth:`sys.stdin.readline` are used. (This means that by importing + :mod:`readline`, on systems that support it, the interpreter will automatically + support :program:`Emacs`\ -like line editing and command-history keystrokes.) + diff --git a/Doc/library/code.rst b/Doc/library/code.rst new file mode 100644 index 0000000..4e00639 --- /dev/null +++ b/Doc/library/code.rst @@ -0,0 +1,167 @@ + +:mod:`code` --- Interpreter base classes +======================================== + +.. module:: code + :synopsis: Facilities to implement read-eval-print loops. + + + +The ``code`` module provides facilities to implement read-eval-print loops in +Python. Two classes and convenience functions are included which can be used to +build applications which provide an interactive interpreter prompt. + + +.. class:: InteractiveInterpreter([locals]) + + This class deals with parsing and interpreter state (the user's namespace); it + does not deal with input buffering or prompting or input file naming (the + filename is always passed in explicitly). The optional *locals* argument + specifies the dictionary in which code will be executed; it defaults to a newly + created dictionary with key ``'__name__'`` set to ``'__console__'`` and key + ``'__doc__'`` set to ``None``. + + +.. class:: InteractiveConsole([locals[, filename]]) + + Closely emulate the behavior of the interactive Python interpreter. This class + builds on :class:`InteractiveInterpreter` and adds prompting using the familiar + ``sys.ps1`` and ``sys.ps2``, and input buffering. + + +.. function:: interact([banner[, readfunc[, local]]]) + + Convenience function to run a read-eval-print loop. This creates a new instance + of :class:`InteractiveConsole` and sets *readfunc* to be used as the + :meth:`raw_input` method, if provided. If *local* is provided, it is passed to + the :class:`InteractiveConsole` constructor for use as the default namespace for + the interpreter loop. The :meth:`interact` method of the instance is then run + with *banner* passed as the banner to use, if provided. The console object is + discarded after use. + + +.. function:: compile_command(source[, filename[, symbol]]) + + This function is useful for programs that want to emulate Python's interpreter + main loop (a.k.a. the read-eval-print loop). The tricky part is to determine + when the user has entered an incomplete command that can be completed by + entering more text (as opposed to a complete command or a syntax error). This + function *almost* always makes the same decision as the real interpreter main + loop. + + *source* is the source string; *filename* is the optional filename from which + source was read, defaulting to ``''``; and *symbol* is the optional + grammar start symbol, which should be either ``'single'`` (the default) or + ``'eval'``. + + Returns a code object (the same as ``compile(source, filename, symbol)``) if the + command is complete and valid; ``None`` if the command is incomplete; raises + :exc:`SyntaxError` if the command is complete and contains a syntax error, or + raises :exc:`OverflowError` or :exc:`ValueError` if the command contains an + invalid literal. + + +.. _interpreter-objects: + +Interactive Interpreter Objects +------------------------------- + + +.. method:: InteractiveInterpreter.runsource(source[, filename[, symbol]]) + + Compile and run some source in the interpreter. Arguments are the same as for + :func:`compile_command`; the default for *filename* is ``''``, and for + *symbol* is ``'single'``. One several things can happen: + + * The input is incorrect; :func:`compile_command` raised an exception + (:exc:`SyntaxError` or :exc:`OverflowError`). A syntax traceback will be + printed by calling the :meth:`showsyntaxerror` method. :meth:`runsource` + returns ``False``. + + * The input is incomplete, and more input is required; :func:`compile_command` + returned ``None``. :meth:`runsource` returns ``True``. + + * The input is complete; :func:`compile_command` returned a code object. The + code is executed by calling the :meth:`runcode` (which also handles run-time + exceptions, except for :exc:`SystemExit`). :meth:`runsource` returns ``False``. + + The return value can be used to decide whether to use ``sys.ps1`` or ``sys.ps2`` + to prompt the next line. + + +.. method:: InteractiveInterpreter.runcode(code) + + Execute a code object. When an exception occurs, :meth:`showtraceback` is called + to display a traceback. All exceptions are caught except :exc:`SystemExit`, + which is allowed to propagate. + + A note about :exc:`KeyboardInterrupt`: this exception may occur elsewhere in + this code, and may not always be caught. The caller should be prepared to deal + with it. + + +.. method:: InteractiveInterpreter.showsyntaxerror([filename]) + + Display the syntax error that just occurred. This does not display a stack + trace because there isn't one for syntax errors. If *filename* is given, it is + stuffed into the exception instead of the default filename provided by Python's + parser, because it always uses ``''`` when reading from a string. The + output is written by the :meth:`write` method. + + +.. method:: InteractiveInterpreter.showtraceback() + + Display the exception that just occurred. We remove the first stack item + because it is within the interpreter object implementation. The output is + written by the :meth:`write` method. + + +.. method:: InteractiveInterpreter.write(data) + + Write a string to the standard error stream (``sys.stderr``). Derived classes + should override this to provide the appropriate output handling as needed. + + +.. _console-objects: + +Interactive Console Objects +--------------------------- + +The :class:`InteractiveConsole` class is a subclass of +:class:`InteractiveInterpreter`, and so offers all the methods of the +interpreter objects as well as the following additions. + + +.. method:: InteractiveConsole.interact([banner]) + + Closely emulate the interactive Python console. The optional banner argument + specify the banner to print before the first interaction; by default it prints a + banner similar to the one printed by the standard Python interpreter, followed + by the class name of the console object in parentheses (so as not to confuse + this with the real interpreter -- since it's so close!). + + +.. method:: InteractiveConsole.push(line) + + Push a line of source text to the interpreter. The line should not have a + trailing newline; it may have internal newlines. The line is appended to a + buffer and the interpreter's :meth:`runsource` method is called with the + concatenated contents of the buffer as source. If this indicates that the + command was executed or invalid, the buffer is reset; otherwise, the command is + incomplete, and the buffer is left as it was after the line was appended. The + return value is ``True`` if more input is required, ``False`` if the line was + dealt with in some way (this is the same as :meth:`runsource`). + + +.. method:: InteractiveConsole.resetbuffer() + + Remove any unhandled source text from the input buffer. + + +.. method:: InteractiveConsole.raw_input([prompt]) + + Write a prompt and read a line. The returned line does not include the trailing + newline. When the user enters the EOF key sequence, :exc:`EOFError` is raised. + The base implementation reads from ``sys.stdin``; a subclass may replace this + with a different implementation. + diff --git a/Doc/library/codecs.rst b/Doc/library/codecs.rst new file mode 100644 index 0000000..38264df --- /dev/null +++ b/Doc/library/codecs.rst @@ -0,0 +1,1230 @@ + +:mod:`codecs` --- Codec registry and base classes +================================================= + +.. module:: codecs + :synopsis: Encode and decode data and streams. +.. moduleauthor:: Marc-Andre Lemburg +.. sectionauthor:: Marc-Andre Lemburg +.. sectionauthor:: Martin v. Löwis + + +.. index:: + single: Unicode + single: Codecs + pair: Codecs; encode + pair: Codecs; decode + single: streams + pair: stackable; streams + +This module defines base classes for standard Python codecs (encoders and +decoders) and provides access to the internal Python codec registry which +manages the codec and error handling lookup process. + +It defines the following functions: + + +.. function:: register(search_function) + + Register a codec search function. Search functions are expected to take one + argument, the encoding name in all lower case letters, and return a + :class:`CodecInfo` object having the following attributes: + + * ``name`` The name of the encoding; + + * ``encoder`` The stateless encoding function; + + * ``decoder`` The stateless decoding function; + + * ``incrementalencoder`` An incremental encoder class or factory function; + + * ``incrementaldecoder`` An incremental decoder class or factory function; + + * ``streamwriter`` A stream writer class or factory function; + + * ``streamreader`` A stream reader class or factory function. + + The various functions or classes take the following arguments: + + *encoder* and *decoder*: These must be functions or methods which have the same + interface as the :meth:`encode`/:meth:`decode` methods of Codec instances (see + Codec Interface). The functions/methods are expected to work in a stateless + mode. + + *incrementalencoder* and *incrementalencoder*: These have to be factory + functions providing the following interface: + + ``factory(errors='strict')`` + + The factory functions must return objects providing the interfaces defined by + the base classes :class:`IncrementalEncoder` and :class:`IncrementalEncoder`, + respectively. Incremental codecs can maintain state. + + *streamreader* and *streamwriter*: These have to be factory functions providing + the following interface: + + ``factory(stream, errors='strict')`` + + The factory functions must return objects providing the interfaces defined by + the base classes :class:`StreamWriter` and :class:`StreamReader`, respectively. + Stream codecs can maintain state. + + Possible values for errors are ``'strict'`` (raise an exception in case of an + encoding error), ``'replace'`` (replace malformed data with a suitable + replacement marker, such as ``'?'``), ``'ignore'`` (ignore malformed data and + continue without further notice), ``'xmlcharrefreplace'`` (replace with the + appropriate XML character reference (for encoding only)) and + ``'backslashreplace'`` (replace with backslashed escape sequences (for encoding + only)) as well as any other error handling name defined via + :func:`register_error`. + + In case a search function cannot find a given encoding, it should return + ``None``. + + +.. function:: lookup(encoding) + + Looks up the codec info in the Python codec registry and returns a + :class:`CodecInfo` object as defined above. + + Encodings are first looked up in the registry's cache. If not found, the list of + registered search functions is scanned. If no :class:`CodecInfo` object is + found, a :exc:`LookupError` is raised. Otherwise, the :class:`CodecInfo` object + is stored in the cache and returned to the caller. + +To simplify access to the various codecs, the module provides these additional +functions which use :func:`lookup` for the codec lookup: + + +.. function:: getencoder(encoding) + + Look up the codec for the given encoding and return its encoder function. + + Raises a :exc:`LookupError` in case the encoding cannot be found. + + +.. function:: getdecoder(encoding) + + Look up the codec for the given encoding and return its decoder function. + + Raises a :exc:`LookupError` in case the encoding cannot be found. + + +.. function:: getincrementalencoder(encoding) + + Look up the codec for the given encoding and return its incremental encoder + class or factory function. + + Raises a :exc:`LookupError` in case the encoding cannot be found or the codec + doesn't support an incremental encoder. + + .. versionadded:: 2.5 + + +.. function:: getincrementaldecoder(encoding) + + Look up the codec for the given encoding and return its incremental decoder + class or factory function. + + Raises a :exc:`LookupError` in case the encoding cannot be found or the codec + doesn't support an incremental decoder. + + .. versionadded:: 2.5 + + +.. function:: getreader(encoding) + + Look up the codec for the given encoding and return its StreamReader class or + factory function. + + Raises a :exc:`LookupError` in case the encoding cannot be found. + + +.. function:: getwriter(encoding) + + Look up the codec for the given encoding and return its StreamWriter class or + factory function. + + Raises a :exc:`LookupError` in case the encoding cannot be found. + + +.. function:: register_error(name, error_handler) + + Register the error handling function *error_handler* under the name *name*. + *error_handler* will be called during encoding and decoding in case of an error, + when *name* is specified as the errors parameter. + + For encoding *error_handler* will be called with a :exc:`UnicodeEncodeError` + instance, which contains information about the location of the error. The error + handler must either raise this or a different exception or return a tuple with a + replacement for the unencodable part of the input and a position where encoding + should continue. The encoder will encode the replacement and continue encoding + the original input at the specified position. Negative position values will be + treated as being relative to the end of the input string. If the resulting + position is out of bound an :exc:`IndexError` will be raised. + + Decoding and translating works similar, except :exc:`UnicodeDecodeError` or + :exc:`UnicodeTranslateError` will be passed to the handler and that the + replacement from the error handler will be put into the output directly. + + +.. function:: lookup_error(name) + + Return the error handler previously registered under the name *name*. + + Raises a :exc:`LookupError` in case the handler cannot be found. + + +.. function:: strict_errors(exception) + + Implements the ``strict`` error handling. + + +.. function:: replace_errors(exception) + + Implements the ``replace`` error handling. + + +.. function:: ignore_errors(exception) + + Implements the ``ignore`` error handling. + + +.. function:: xmlcharrefreplace_errors_errors(exception) + + Implements the ``xmlcharrefreplace`` error handling. + + +.. function:: backslashreplace_errors_errors(exception) + + Implements the ``backslashreplace`` error handling. + +To simplify working with encoded files or stream, the module also defines these +utility functions: + + +.. function:: open(filename, mode[, encoding[, errors[, buffering]]]) + + Open an encoded file using the given *mode* and return a wrapped version + providing transparent encoding/decoding. + + .. note:: + + The wrapped version will only accept the object format defined by the codecs, + i.e. Unicode objects for most built-in codecs. Output is also codec-dependent + and will usually be Unicode as well. + + *encoding* specifies the encoding which is to be used for the file. + + *errors* may be given to define the error handling. It defaults to ``'strict'`` + which causes a :exc:`ValueError` to be raised in case an encoding error occurs. + + *buffering* has the same meaning as for the built-in :func:`open` function. It + defaults to line buffered. + + +.. function:: EncodedFile(file, input[, output[, errors]]) + + Return a wrapped version of file which provides transparent encoding + translation. + + Strings written to the wrapped file are interpreted according to the given + *input* encoding and then written to the original file as strings using the + *output* encoding. The intermediate encoding will usually be Unicode but depends + on the specified codecs. + + If *output* is not given, it defaults to *input*. + + *errors* may be given to define the error handling. It defaults to ``'strict'``, + which causes :exc:`ValueError` to be raised in case an encoding error occurs. + + +.. function:: iterencode(iterable, encoding[, errors]) + + Uses an incremental encoder to iteratively encode the input provided by + *iterable*. This function is a generator. *errors* (as well as any other keyword + argument) is passed through to the incremental encoder. + + .. versionadded:: 2.5 + + +.. function:: iterdecode(iterable, encoding[, errors]) + + Uses an incremental decoder to iteratively decode the input provided by + *iterable*. This function is a generator. *errors* (as well as any other keyword + argument) is passed through to the incremental decoder. + + .. versionadded:: 2.5 + +The module also provides the following constants which are useful for reading +and writing to platform dependent files: + + +.. data:: BOM + BOM_BE + BOM_LE + BOM_UTF8 + BOM_UTF16 + BOM_UTF16_BE + BOM_UTF16_LE + BOM_UTF32 + BOM_UTF32_BE + BOM_UTF32_LE + + These constants define various encodings of the Unicode byte order mark (BOM) + used in UTF-16 and UTF-32 data streams to indicate the byte order used in the + stream or file and in UTF-8 as a Unicode signature. :const:`BOM_UTF16` is either + :const:`BOM_UTF16_BE` or :const:`BOM_UTF16_LE` depending on the platform's + native byte order, :const:`BOM` is an alias for :const:`BOM_UTF16`, + :const:`BOM_LE` for :const:`BOM_UTF16_LE` and :const:`BOM_BE` for + :const:`BOM_UTF16_BE`. The others represent the BOM in UTF-8 and UTF-32 + encodings. + + +.. _codec-base-classes: + +Codec Base Classes +------------------ + +The :mod:`codecs` module defines a set of base classes which define the +interface and can also be used to easily write you own codecs for use in Python. + +Each codec has to define four interfaces to make it usable as codec in Python: +stateless encoder, stateless decoder, stream reader and stream writer. The +stream reader and writers typically reuse the stateless encoder/decoder to +implement the file protocols. + +The :class:`Codec` class defines the interface for stateless encoders/decoders. + +To simplify and standardize error handling, the :meth:`encode` and +:meth:`decode` methods may implement different error handling schemes by +providing the *errors* string argument. The following string values are defined +and implemented by all standard Python codecs: + ++-------------------------+-----------------------------------------------+ +| Value | Meaning | ++=========================+===============================================+ +| ``'strict'`` | Raise :exc:`UnicodeError` (or a subclass); | +| | this is the default. | ++-------------------------+-----------------------------------------------+ +| ``'ignore'`` | Ignore the character and continue with the | +| | next. | ++-------------------------+-----------------------------------------------+ +| ``'replace'`` | Replace with a suitable replacement | +| | character; Python will use the official | +| | U+FFFD REPLACEMENT CHARACTER for the built-in | +| | Unicode codecs on decoding and '?' on | +| | encoding. | ++-------------------------+-----------------------------------------------+ +| ``'xmlcharrefreplace'`` | Replace with the appropriate XML character | +| | reference (only for encoding). | ++-------------------------+-----------------------------------------------+ +| ``'backslashreplace'`` | Replace with backslashed escape sequences | +| | (only for encoding). | ++-------------------------+-----------------------------------------------+ + +The set of allowed values can be extended via :meth:`register_error`. + + +.. _codec-objects: + +Codec Objects +^^^^^^^^^^^^^ + +The :class:`Codec` class defines these methods which also define the function +interfaces of the stateless encoder and decoder: + + +.. method:: Codec.encode(input[, errors]) + + Encodes the object *input* and returns a tuple (output object, length consumed). + While codecs are not restricted to use with Unicode, in a Unicode context, + encoding converts a Unicode object to a plain string using a particular + character set encoding (e.g., ``cp1252`` or ``iso-8859-1``). + + *errors* defines the error handling to apply. It defaults to ``'strict'`` + handling. + + The method may not store state in the :class:`Codec` instance. Use + :class:`StreamCodec` for codecs which have to keep state in order to make + encoding/decoding efficient. + + The encoder must be able to handle zero length input and return an empty object + of the output object type in this situation. + + +.. method:: Codec.decode(input[, errors]) + + Decodes the object *input* and returns a tuple (output object, length consumed). + In a Unicode context, decoding converts a plain string encoded using a + particular character set encoding to a Unicode object. + + *input* must be an object which provides the ``bf_getreadbuf`` buffer slot. + Python strings, buffer objects and memory mapped files are examples of objects + providing this slot. + + *errors* defines the error handling to apply. It defaults to ``'strict'`` + handling. + + The method may not store state in the :class:`Codec` instance. Use + :class:`StreamCodec` for codecs which have to keep state in order to make + encoding/decoding efficient. + + The decoder must be able to handle zero length input and return an empty object + of the output object type in this situation. + +The :class:`IncrementalEncoder` and :class:`IncrementalDecoder` classes provide +the basic interface for incremental encoding and decoding. Encoding/decoding the +input isn't done with one call to the stateless encoder/decoder function, but +with multiple calls to the :meth:`encode`/:meth:`decode` method of the +incremental encoder/decoder. The incremental encoder/decoder keeps track of the +encoding/decoding process during method calls. + +The joined output of calls to the :meth:`encode`/:meth:`decode` method is the +same as if all the single inputs were joined into one, and this input was +encoded/decoded with the stateless encoder/decoder. + + +.. _incremental-encoder-objects: + +IncrementalEncoder Objects +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +.. versionadded:: 2.5 + +The :class:`IncrementalEncoder` class is used for encoding an input in multiple +steps. It defines the following methods which every incremental encoder must +define in order to be compatible with the Python codec registry. + + +.. class:: IncrementalEncoder([errors]) + + Constructor for an :class:`IncrementalEncoder` instance. + + All incremental encoders must provide this constructor interface. They are free + to add additional keyword arguments, but only the ones defined here are used by + the Python codec registry. + + The :class:`IncrementalEncoder` may implement different error handling schemes + by providing the *errors* keyword argument. These parameters are predefined: + + * ``'strict'`` Raise :exc:`ValueError` (or a subclass); this is the default. + + * ``'ignore'`` Ignore the character and continue with the next. + + * ``'replace'`` Replace with a suitable replacement character + + * ``'xmlcharrefreplace'`` Replace with the appropriate XML character reference + + * ``'backslashreplace'`` Replace with backslashed escape sequences. + + The *errors* argument will be assigned to an attribute of the same name. + Assigning to this attribute makes it possible to switch between different error + handling strategies during the lifetime of the :class:`IncrementalEncoder` + object. + + The set of allowed values for the *errors* argument can be extended with + :func:`register_error`. + + +.. method:: IncrementalEncoder.encode(object[, final]) + + Encodes *object* (taking the current state of the encoder into account) and + returns the resulting encoded object. If this is the last call to :meth:`encode` + *final* must be true (the default is false). + + +.. method:: IncrementalEncoder.reset() + + Reset the encoder to the initial state. + + +.. method:: IncrementalEncoder.getstate() + + Return the current state of the encoder which must be an integer. The + implementation should make sure that ``0`` is the most common state. (States + that are more complicated than integers can be converted into an integer by + marshaling/pickling the state and encoding the bytes of the resulting string + into an integer). + + .. versionadded:: 3.0 + + +.. method:: IncrementalEncoder.setstate(state) + + Set the state of the encoder to *state*. *state* must be an encoder state + returned by :meth:`getstate`. + + .. versionadded:: 3.0 + + +.. _incremental-decoder-objects: + +IncrementalDecoder Objects +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The :class:`IncrementalDecoder` class is used for decoding an input in multiple +steps. It defines the following methods which every incremental decoder must +define in order to be compatible with the Python codec registry. + + +.. class:: IncrementalDecoder([errors]) + + Constructor for an :class:`IncrementalDecoder` instance. + + All incremental decoders must provide this constructor interface. They are free + to add additional keyword arguments, but only the ones defined here are used by + the Python codec registry. + + The :class:`IncrementalDecoder` may implement different error handling schemes + by providing the *errors* keyword argument. These parameters are predefined: + + * ``'strict'`` Raise :exc:`ValueError` (or a subclass); this is the default. + + * ``'ignore'`` Ignore the character and continue with the next. + + * ``'replace'`` Replace with a suitable replacement character. + + The *errors* argument will be assigned to an attribute of the same name. + Assigning to this attribute makes it possible to switch between different error + handling strategies during the lifetime of the :class:`IncrementalEncoder` + object. + + The set of allowed values for the *errors* argument can be extended with + :func:`register_error`. + + +.. method:: IncrementalDecoder.decode(object[, final]) + + Decodes *object* (taking the current state of the decoder into account) and + returns the resulting decoded object. If this is the last call to :meth:`decode` + *final* must be true (the default is false). If *final* is true the decoder must + decode the input completely and must flush all buffers. If this isn't possible + (e.g. because of incomplete byte sequences at the end of the input) it must + initiate error handling just like in the stateless case (which might raise an + exception). + + +.. method:: IncrementalDecoder.reset() + + Reset the decoder to the initial state. + + +.. method:: IncrementalDecoder.getstate() + + Return the current state of the decoder. This must be a tuple with two items, + the first must be the buffer containing the still undecoded input. The second + must be an integer and can be additional state info. (The implementation should + make sure that ``0`` is the most common additional state info.) If this + additional state info is ``0`` it must be possible to set the decoder to the + state which has no input buffered and ``0`` as the additional state info, so + that feeding the previously buffered input to the decoder returns it to the + previous state without producing any output. (Additional state info that is more + complicated than integers can be converted into an integer by + marshaling/pickling the info and encoding the bytes of the resulting string into + an integer.) + + .. versionadded:: 3.0 + + +.. method:: IncrementalDecoder.setstate(state) + + Set the state of the encoder to *state*. *state* must be a decoder state + returned by :meth:`getstate`. + + .. versionadded:: 3.0 + +The :class:`StreamWriter` and :class:`StreamReader` classes provide generic +working interfaces which can be used to implement new encoding submodules very +easily. See :mod:`encodings.utf_8` for an example of how this is done. + + +.. _stream-writer-objects: + +StreamWriter Objects +^^^^^^^^^^^^^^^^^^^^ + +The :class:`StreamWriter` class is a subclass of :class:`Codec` and defines the +following methods which every stream writer must define in order to be +compatible with the Python codec registry. + + +.. class:: StreamWriter(stream[, errors]) + + Constructor for a :class:`StreamWriter` instance. + + All stream writers must provide this constructor interface. They are free to add + additional keyword arguments, but only the ones defined here are used by the + Python codec registry. + + *stream* must be a file-like object open for writing binary data. + + The :class:`StreamWriter` may implement different error handling schemes by + providing the *errors* keyword argument. These parameters are predefined: + + * ``'strict'`` Raise :exc:`ValueError` (or a subclass); this is the default. + + * ``'ignore'`` Ignore the character and continue with the next. + + * ``'replace'`` Replace with a suitable replacement character + + * ``'xmlcharrefreplace'`` Replace with the appropriate XML character reference + + * ``'backslashreplace'`` Replace with backslashed escape sequences. + + The *errors* argument will be assigned to an attribute of the same name. + Assigning to this attribute makes it possible to switch between different error + handling strategies during the lifetime of the :class:`StreamWriter` object. + + The set of allowed values for the *errors* argument can be extended with + :func:`register_error`. + + +.. method:: StreamWriter.write(object) + + Writes the object's contents encoded to the stream. + + +.. method:: StreamWriter.writelines(list) + + Writes the concatenated list of strings to the stream (possibly by reusing the + :meth:`write` method). + + +.. method:: StreamWriter.reset() + + Flushes and resets the codec buffers used for keeping state. + + Calling this method should ensure that the data on the output is put into a + clean state that allows appending of new fresh data without having to rescan the + whole stream to recover state. + +In addition to the above methods, the :class:`StreamWriter` must also inherit +all other methods and attributes from the underlying stream. + + +.. _stream-reader-objects: + +StreamReader Objects +^^^^^^^^^^^^^^^^^^^^ + +The :class:`StreamReader` class is a subclass of :class:`Codec` and defines the +following methods which every stream reader must define in order to be +compatible with the Python codec registry. + + +.. class:: StreamReader(stream[, errors]) + + Constructor for a :class:`StreamReader` instance. + + All stream readers must provide this constructor interface. They are free to add + additional keyword arguments, but only the ones defined here are used by the + Python codec registry. + + *stream* must be a file-like object open for reading (binary) data. + + The :class:`StreamReader` may implement different error handling schemes by + providing the *errors* keyword argument. These parameters are defined: + + * ``'strict'`` Raise :exc:`ValueError` (or a subclass); this is the default. + + * ``'ignore'`` Ignore the character and continue with the next. + + * ``'replace'`` Replace with a suitable replacement character. + + The *errors* argument will be assigned to an attribute of the same name. + Assigning to this attribute makes it possible to switch between different error + handling strategies during the lifetime of the :class:`StreamReader` object. + + The set of allowed values for the *errors* argument can be extended with + :func:`register_error`. + + +.. method:: StreamReader.read([size[, chars, [firstline]]]) + + Decodes data from the stream and returns the resulting object. + + *chars* indicates the number of characters to read from the stream. :func:`read` + will never return more than *chars* characters, but it might return less, if + there are not enough characters available. + + *size* indicates the approximate maximum number of bytes to read from the stream + for decoding purposes. The decoder can modify this setting as appropriate. The + default value -1 indicates to read and decode as much as possible. *size* is + intended to prevent having to decode huge files in one step. + + *firstline* indicates that it would be sufficient to only return the first line, + if there are decoding errors on later lines. + + The method should use a greedy read strategy meaning that it should read as much + data as is allowed within the definition of the encoding and the given size, + e.g. if optional encoding endings or state markers are available on the stream, + these should be read too. + + .. versionchanged:: 2.4 + *chars* argument added. + + .. versionchanged:: 2.4.2 + *firstline* argument added. + + +.. method:: StreamReader.readline([size[, keepends]]) + + Read one line from the input stream and return the decoded data. + + *size*, if given, is passed as size argument to the stream's :meth:`readline` + method. + + If *keepends* is false line-endings will be stripped from the lines returned. + + .. versionchanged:: 2.4 + *keepends* argument added. + + +.. method:: StreamReader.readlines([sizehint[, keepends]]) + + Read all lines available on the input stream and return them as a list of lines. + + Line-endings are implemented using the codec's decoder method and are included + in the list entries if *keepends* is true. + + *sizehint*, if given, is passed as the *size* argument to the stream's + :meth:`read` method. + + +.. method:: StreamReader.reset() + + Resets the codec buffers used for keeping state. + + Note that no stream repositioning should take place. This method is primarily + intended to be able to recover from decoding errors. + +In addition to the above methods, the :class:`StreamReader` must also inherit +all other methods and attributes from the underlying stream. + +The next two base classes are included for convenience. They are not needed by +the codec registry, but may provide useful in practice. + + +.. _stream-reader-writer: + +StreamReaderWriter Objects +^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The :class:`StreamReaderWriter` allows wrapping streams which work in both read +and write modes. + +The design is such that one can use the factory functions returned by the +:func:`lookup` function to construct the instance. + + +.. class:: StreamReaderWriter(stream, Reader, Writer, errors) + + Creates a :class:`StreamReaderWriter` instance. *stream* must be a file-like + object. *Reader* and *Writer* must be factory functions or classes providing the + :class:`StreamReader` and :class:`StreamWriter` interface resp. Error handling + is done in the same way as defined for the stream readers and writers. + +:class:`StreamReaderWriter` instances define the combined interfaces of +:class:`StreamReader` and :class:`StreamWriter` classes. They inherit all other +methods and attributes from the underlying stream. + + +.. _stream-recoder-objects: + +StreamRecoder Objects +^^^^^^^^^^^^^^^^^^^^^ + +The :class:`StreamRecoder` provide a frontend - backend view of encoding data +which is sometimes useful when dealing with different encoding environments. + +The design is such that one can use the factory functions returned by the +:func:`lookup` function to construct the instance. + + +.. class:: StreamRecoder(stream, encode, decode, Reader, Writer, errors) + + Creates a :class:`StreamRecoder` instance which implements a two-way conversion: + *encode* and *decode* work on the frontend (the input to :meth:`read` and output + of :meth:`write`) while *Reader* and *Writer* work on the backend (reading and + writing to the stream). + + You can use these objects to do transparent direct recodings from e.g. Latin-1 + to UTF-8 and back. + + *stream* must be a file-like object. + + *encode*, *decode* must adhere to the :class:`Codec` interface. *Reader*, + *Writer* must be factory functions or classes providing objects of the + :class:`StreamReader` and :class:`StreamWriter` interface respectively. + + *encode* and *decode* are needed for the frontend translation, *Reader* and + *Writer* for the backend translation. The intermediate format used is + determined by the two sets of codecs, e.g. the Unicode codecs will use Unicode + as the intermediate encoding. + + Error handling is done in the same way as defined for the stream readers and + writers. + +:class:`StreamRecoder` instances define the combined interfaces of +:class:`StreamReader` and :class:`StreamWriter` classes. They inherit all other +methods and attributes from the underlying stream. + + +.. _encodings-overview: + +Encodings and Unicode +--------------------- + +Unicode strings are stored internally as sequences of codepoints (to be precise +as :ctype:`Py_UNICODE` arrays). Depending on the way Python is compiled (either +via :option:`--enable-unicode=ucs2` or :option:`--enable-unicode=ucs4`, with the +former being the default) :ctype:`Py_UNICODE` is either a 16-bit or 32-bit data +type. Once a Unicode object is used outside of CPU and memory, CPU endianness +and how these arrays are stored as bytes become an issue. Transforming a +unicode object into a sequence of bytes is called encoding and recreating the +unicode object from the sequence of bytes is known as decoding. There are many +different methods for how this transformation can be done (these methods are +also called encodings). The simplest method is to map the codepoints 0-255 to +the bytes ``0x0``-``0xff``. This means that a unicode object that contains +codepoints above ``U+00FF`` can't be encoded with this method (which is called +``'latin-1'`` or ``'iso-8859-1'``). :func:`unicode.encode` will raise a +:exc:`UnicodeEncodeError` that looks like this: ``UnicodeEncodeError: 'latin-1' +codec can't encode character u'\u1234' in position 3: ordinal not in +range(256)``. + +There's another group of encodings (the so called charmap encodings) that choose +a different subset of all unicode code points and how these codepoints are +mapped to the bytes ``0x0``-``0xff``. To see how this is done simply open +e.g. :file:`encodings/cp1252.py` (which is an encoding that is used primarily on +Windows). There's a string constant with 256 characters that shows you which +character is mapped to which byte value. + +All of these encodings can only encode 256 of the 65536 (or 1114111) codepoints +defined in unicode. A simple and straightforward way that can store each Unicode +code point, is to store each codepoint as two consecutive bytes. There are two +possibilities: Store the bytes in big endian or in little endian order. These +two encodings are called UTF-16-BE and UTF-16-LE respectively. Their +disadvantage is that if e.g. you use UTF-16-BE on a little endian machine you +will always have to swap bytes on encoding and decoding. UTF-16 avoids this +problem: Bytes will always be in natural endianness. When these bytes are read +by a CPU with a different endianness, then bytes have to be swapped though. To +be able to detect the endianness of a UTF-16 byte sequence, there's the so +called BOM (the "Byte Order Mark"). This is the Unicode character ``U+FEFF``. +This character will be prepended to every UTF-16 byte sequence. The byte swapped +version of this character (``0xFFFE``) is an illegal character that may not +appear in a Unicode text. So when the first character in an UTF-16 byte sequence +appears to be a ``U+FFFE`` the bytes have to be swapped on decoding. +Unfortunately upto Unicode 4.0 the character ``U+FEFF`` had a second purpose as +a ``ZERO WIDTH NO-BREAK SPACE``: A character that has no width and doesn't allow +a word to be split. It can e.g. be used to give hints to a ligature algorithm. +With Unicode 4.0 using ``U+FEFF`` as a ``ZERO WIDTH NO-BREAK SPACE`` has been +deprecated (with ``U+2060`` (``WORD JOINER``) assuming this role). Nevertheless +Unicode software still must be able to handle ``U+FEFF`` in both roles: As a BOM +it's a device to determine the storage layout of the encoded bytes, and vanishes +once the byte sequence has been decoded into a Unicode string; as a ``ZERO WIDTH +NO-BREAK SPACE`` it's a normal character that will be decoded like any other. + +There's another encoding that is able to encoding the full range of Unicode +characters: UTF-8. UTF-8 is an 8-bit encoding, which means there are no issues +with byte order in UTF-8. Each byte in a UTF-8 byte sequence consists of two +parts: Marker bits (the most significant bits) and payload bits. The marker bits +are a sequence of zero to six 1 bits followed by a 0 bit. Unicode characters are +encoded like this (with x being payload bits, which when concatenated give the +Unicode character): + ++-----------------------------------+----------------------------------------------+ +| Range | Encoding | ++===================================+==============================================+ +| ``U-00000000`` ... ``U-0000007F`` | 0xxxxxxx | ++-----------------------------------+----------------------------------------------+ +| ``U-00000080`` ... ``U-000007FF`` | 110xxxxx 10xxxxxx | ++-----------------------------------+----------------------------------------------+ +| ``U-00000800`` ... ``U-0000FFFF`` | 1110xxxx 10xxxxxx 10xxxxxx | ++-----------------------------------+----------------------------------------------+ +| ``U-00010000`` ... ``U-001FFFFF`` | 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx | ++-----------------------------------+----------------------------------------------+ +| ``U-00200000`` ... ``U-03FFFFFF`` | 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx | ++-----------------------------------+----------------------------------------------+ +| ``U-04000000`` ... ``U-7FFFFFFF`` | 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx | +| | 10xxxxxx | ++-----------------------------------+----------------------------------------------+ + +The least significant bit of the Unicode character is the rightmost x bit. + +As UTF-8 is an 8-bit encoding no BOM is required and any ``U+FEFF`` character in +the decoded Unicode string (even if it's the first character) is treated as a +``ZERO WIDTH NO-BREAK SPACE``. + +Without external information it's impossible to reliably determine which +encoding was used for encoding a Unicode string. Each charmap encoding can +decode any random byte sequence. However that's not possible with UTF-8, as +UTF-8 byte sequences have a structure that doesn't allow arbitrary byte +sequence. To increase the reliability with which a UTF-8 encoding can be +detected, Microsoft invented a variant of UTF-8 (that Python 2.5 calls +``"utf-8-sig"``) for its Notepad program: Before any of the Unicode characters +is written to the file, a UTF-8 encoded BOM (which looks like this as a byte +sequence: ``0xef``, ``0xbb``, ``0xbf``) is written. As it's rather improbable +that any charmap encoded file starts with these byte values (which would e.g. +map to + + | LATIN SMALL LETTER I WITH DIAERESIS + | RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK + | INVERTED QUESTION MARK + +in iso-8859-1), this increases the probability that a utf-8-sig encoding can be +correctly guessed from the byte sequence. So here the BOM is not used to be able +to determine the byte order used for generating the byte sequence, but as a +signature that helps in guessing the encoding. On encoding the utf-8-sig codec +will write ``0xef``, ``0xbb``, ``0xbf`` as the first three bytes to the file. On +decoding utf-8-sig will skip those three bytes if they appear as the first three +bytes in the file. + + +.. _standard-encodings: + +Standard Encodings +------------------ + +Python comes with a number of codecs built-in, either implemented as C functions +or with dictionaries as mapping tables. The following table lists the codecs by +name, together with a few common aliases, and the languages for which the +encoding is likely used. Neither the list of aliases nor the list of languages +is meant to be exhaustive. Notice that spelling alternatives that only differ in +case or use a hyphen instead of an underscore are also valid aliases. + +Many of the character sets support the same languages. They vary in individual +characters (e.g. whether the EURO SIGN is supported or not), and in the +assignment of characters to code positions. For the European languages in +particular, the following variants typically exist: + +* an ISO 8859 codeset + +* a Microsoft Windows code page, which is typically derived from a 8859 codeset, + but replaces control characters with additional graphic characters + +* an IBM EBCDIC code page + +* an IBM PC code page, which is ASCII compatible + ++-----------------+--------------------------------+--------------------------------+ +| Codec | Aliases | Languages | ++=================+================================+================================+ +| ascii | 646, us-ascii | English | ++-----------------+--------------------------------+--------------------------------+ +| big5 | big5-tw, csbig5 | Traditional Chinese | ++-----------------+--------------------------------+--------------------------------+ +| big5hkscs | big5-hkscs, hkscs | Traditional Chinese | ++-----------------+--------------------------------+--------------------------------+ +| cp037 | IBM037, IBM039 | English | ++-----------------+--------------------------------+--------------------------------+ +| cp424 | EBCDIC-CP-HE, IBM424 | Hebrew | ++-----------------+--------------------------------+--------------------------------+ +| cp437 | 437, IBM437 | English | ++-----------------+--------------------------------+--------------------------------+ +| cp500 | EBCDIC-CP-BE, EBCDIC-CP-CH, | Western Europe | +| | IBM500 | | ++-----------------+--------------------------------+--------------------------------+ +| cp737 | | Greek | ++-----------------+--------------------------------+--------------------------------+ +| cp775 | IBM775 | Baltic languages | ++-----------------+--------------------------------+--------------------------------+ +| cp850 | 850, IBM850 | Western Europe | ++-----------------+--------------------------------+--------------------------------+ +| cp852 | 852, IBM852 | Central and Eastern Europe | ++-----------------+--------------------------------+--------------------------------+ +| cp855 | 855, IBM855 | Bulgarian, Byelorussian, | +| | | Macedonian, Russian, Serbian | ++-----------------+--------------------------------+--------------------------------+ +| cp856 | | Hebrew | ++-----------------+--------------------------------+--------------------------------+ +| cp857 | 857, IBM857 | Turkish | ++-----------------+--------------------------------+--------------------------------+ +| cp860 | 860, IBM860 | Portuguese | ++-----------------+--------------------------------+--------------------------------+ +| cp861 | 861, CP-IS, IBM861 | Icelandic | ++-----------------+--------------------------------+--------------------------------+ +| cp862 | 862, IBM862 | Hebrew | ++-----------------+--------------------------------+--------------------------------+ +| cp863 | 863, IBM863 | Canadian | ++-----------------+--------------------------------+--------------------------------+ +| cp864 | IBM864 | Arabic | ++-----------------+--------------------------------+--------------------------------+ +| cp865 | 865, IBM865 | Danish, Norwegian | ++-----------------+--------------------------------+--------------------------------+ +| cp866 | 866, IBM866 | Russian | ++-----------------+--------------------------------+--------------------------------+ +| cp869 | 869, CP-GR, IBM869 | Greek | ++-----------------+--------------------------------+--------------------------------+ +| cp874 | | Thai | ++-----------------+--------------------------------+--------------------------------+ +| cp875 | | Greek | ++-----------------+--------------------------------+--------------------------------+ +| cp932 | 932, ms932, mskanji, ms-kanji | Japanese | ++-----------------+--------------------------------+--------------------------------+ +| cp949 | 949, ms949, uhc | Korean | ++-----------------+--------------------------------+--------------------------------+ +| cp950 | 950, ms950 | Traditional Chinese | ++-----------------+--------------------------------+--------------------------------+ +| cp1006 | | Urdu | ++-----------------+--------------------------------+--------------------------------+ +| cp1026 | ibm1026 | Turkish | ++-----------------+--------------------------------+--------------------------------+ +| cp1140 | ibm1140 | Western Europe | ++-----------------+--------------------------------+--------------------------------+ +| cp1250 | windows-1250 | Central and Eastern Europe | ++-----------------+--------------------------------+--------------------------------+ +| cp1251 | windows-1251 | Bulgarian, Byelorussian, | +| | | Macedonian, Russian, Serbian | ++-----------------+--------------------------------+--------------------------------+ +| cp1252 | windows-1252 | Western Europe | ++-----------------+--------------------------------+--------------------------------+ +| cp1253 | windows-1253 | Greek | ++-----------------+--------------------------------+--------------------------------+ +| cp1254 | windows-1254 | Turkish | ++-----------------+--------------------------------+--------------------------------+ +| cp1255 | windows-1255 | Hebrew | ++-----------------+--------------------------------+--------------------------------+ +| cp1256 | windows1256 | Arabic | ++-----------------+--------------------------------+--------------------------------+ +| cp1257 | windows-1257 | Baltic languages | ++-----------------+--------------------------------+--------------------------------+ +| cp1258 | windows-1258 | Vietnamese | ++-----------------+--------------------------------+--------------------------------+ +| euc_jp | eucjp, ujis, u-jis | Japanese | ++-----------------+--------------------------------+--------------------------------+ +| euc_jis_2004 | jisx0213, eucjis2004 | Japanese | ++-----------------+--------------------------------+--------------------------------+ +| euc_jisx0213 | eucjisx0213 | Japanese | ++-----------------+--------------------------------+--------------------------------+ +| euc_kr | euckr, korean, ksc5601, | Korean | +| | ks_c-5601, ks_c-5601-1987, | | +| | ksx1001, ks_x-1001 | | ++-----------------+--------------------------------+--------------------------------+ +| gb2312 | chinese, csiso58gb231280, euc- | Simplified Chinese | +| | cn, euccn, eucgb2312-cn, | | +| | gb2312-1980, gb2312-80, iso- | | +| | ir-58 | | ++-----------------+--------------------------------+--------------------------------+ +| gbk | 936, cp936, ms936 | Unified Chinese | ++-----------------+--------------------------------+--------------------------------+ +| gb18030 | gb18030-2000 | Unified Chinese | ++-----------------+--------------------------------+--------------------------------+ +| hz | hzgb, hz-gb, hz-gb-2312 | Simplified Chinese | ++-----------------+--------------------------------+--------------------------------+ +| iso2022_jp | csiso2022jp, iso2022jp, | Japanese | +| | iso-2022-jp | | ++-----------------+--------------------------------+--------------------------------+ +| iso2022_jp_1 | iso2022jp-1, iso-2022-jp-1 | Japanese | ++-----------------+--------------------------------+--------------------------------+ +| iso2022_jp_2 | iso2022jp-2, iso-2022-jp-2 | Japanese, Korean, Simplified | +| | | Chinese, Western Europe, Greek | ++-----------------+--------------------------------+--------------------------------+ +| iso2022_jp_2004 | iso2022jp-2004, | Japanese | +| | iso-2022-jp-2004 | | ++-----------------+--------------------------------+--------------------------------+ +| iso2022_jp_3 | iso2022jp-3, iso-2022-jp-3 | Japanese | ++-----------------+--------------------------------+--------------------------------+ +| iso2022_jp_ext | iso2022jp-ext, iso-2022-jp-ext | Japanese | ++-----------------+--------------------------------+--------------------------------+ +| iso2022_kr | csiso2022kr, iso2022kr, | Korean | +| | iso-2022-kr | | ++-----------------+--------------------------------+--------------------------------+ +| latin_1 | iso-8859-1, iso8859-1, 8859, | West Europe | +| | cp819, latin, latin1, L1 | | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_2 | iso-8859-2, latin2, L2 | Central and Eastern Europe | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_3 | iso-8859-3, latin3, L3 | Esperanto, Maltese | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_4 | iso-8859-4, latin4, L4 | Baltic languagues | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_5 | iso-8859-5, cyrillic | Bulgarian, Byelorussian, | +| | | Macedonian, Russian, Serbian | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_6 | iso-8859-6, arabic | Arabic | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_7 | iso-8859-7, greek, greek8 | Greek | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_8 | iso-8859-8, hebrew | Hebrew | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_9 | iso-8859-9, latin5, L5 | Turkish | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_10 | iso-8859-10, latin6, L6 | Nordic languages | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_13 | iso-8859-13 | Baltic languages | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_14 | iso-8859-14, latin8, L8 | Celtic languages | ++-----------------+--------------------------------+--------------------------------+ +| iso8859_15 | iso-8859-15 | Western Europe | ++-----------------+--------------------------------+--------------------------------+ +| johab | cp1361, ms1361 | Korean | ++-----------------+--------------------------------+--------------------------------+ +| koi8_r | | Russian | ++-----------------+--------------------------------+--------------------------------+ +| koi8_u | | Ukrainian | ++-----------------+--------------------------------+--------------------------------+ +| mac_cyrillic | maccyrillic | Bulgarian, Byelorussian, | +| | | Macedonian, Russian, Serbian | ++-----------------+--------------------------------+--------------------------------+ +| mac_greek | macgreek | Greek | ++-----------------+--------------------------------+--------------------------------+ +| mac_iceland | maciceland | Icelandic | ++-----------------+--------------------------------+--------------------------------+ +| mac_latin2 | maclatin2, maccentraleurope | Central and Eastern Europe | ++-----------------+--------------------------------+--------------------------------+ +| mac_roman | macroman | Western Europe | ++-----------------+--------------------------------+--------------------------------+ +| mac_turkish | macturkish | Turkish | ++-----------------+--------------------------------+--------------------------------+ +| ptcp154 | csptcp154, pt154, cp154, | Kazakh | +| | cyrillic-asian | | ++-----------------+--------------------------------+--------------------------------+ +| shift_jis | csshiftjis, shiftjis, sjis, | Japanese | +| | s_jis | | ++-----------------+--------------------------------+--------------------------------+ +| shift_jis_2004 | shiftjis2004, sjis_2004, | Japanese | +| | sjis2004 | | ++-----------------+--------------------------------+--------------------------------+ +| shift_jisx0213 | shiftjisx0213, sjisx0213, | Japanese | +| | s_jisx0213 | | ++-----------------+--------------------------------+--------------------------------+ +| utf_16 | U16, utf16 | all languages | ++-----------------+--------------------------------+--------------------------------+ +| utf_16_be | UTF-16BE | all languages (BMP only) | ++-----------------+--------------------------------+--------------------------------+ +| utf_16_le | UTF-16LE | all languages (BMP only) | ++-----------------+--------------------------------+--------------------------------+ +| utf_7 | U7, unicode-1-1-utf-7 | all languages | ++-----------------+--------------------------------+--------------------------------+ +| utf_8 | U8, UTF, utf8 | all languages | ++-----------------+--------------------------------+--------------------------------+ +| utf_8_sig | | all languages | ++-----------------+--------------------------------+--------------------------------+ + +A number of codecs are specific to Python, so their codec names have no meaning +outside Python. Some of them don't convert from Unicode strings to byte strings, +but instead use the property of the Python codecs machinery that any bijective +function with one argument can be considered as an encoding. + +For the codecs listed below, the result in the "encoding" direction is always a +byte string. The result of the "decoding" direction is listed as operand type in +the table. + ++--------------------+---------+----------------+---------------------------+ +| Codec | Aliases | Operand type | Purpose | ++====================+=========+================+===========================+ +| idna | | Unicode string | Implements :rfc:`3490`, | +| | | | see also | +| | | | :mod:`encodings.idna` | ++--------------------+---------+----------------+---------------------------+ +| mbcs | dbcs | Unicode string | Windows only: Encode | +| | | | operand according to the | +| | | | ANSI codepage (CP_ACP) | ++--------------------+---------+----------------+---------------------------+ +| palmos | | Unicode string | Encoding of PalmOS 3.5 | ++--------------------+---------+----------------+---------------------------+ +| punycode | | Unicode string | Implements :rfc:`3492` | ++--------------------+---------+----------------+---------------------------+ +| raw_unicode_escape | | Unicode string | Produce a string that is | +| | | | suitable as raw Unicode | +| | | | literal in Python source | +| | | | code | ++--------------------+---------+----------------+---------------------------+ +| undefined | | any | Raise an exception for | +| | | | all conversions. Can be | +| | | | used as the system | +| | | | encoding if no automatic | +| | | | coercion between byte and | +| | | | Unicode strings is | +| | | | desired. | ++--------------------+---------+----------------+---------------------------+ +| unicode_escape | | Unicode string | Produce a string that is | +| | | | suitable as Unicode | +| | | | literal in Python source | +| | | | code | ++--------------------+---------+----------------+---------------------------+ +| unicode_internal | | Unicode string | Return the internal | +| | | | representation of the | +| | | | operand | ++--------------------+---------+----------------+---------------------------+ + +.. versionadded:: 2.3 + The ``idna`` and ``punycode`` encodings. + + +:mod:`encodings.idna` --- Internationalized Domain Names in Applications +------------------------------------------------------------------------ + +.. module:: encodings.idna + :synopsis: Internationalized Domain Names implementation +.. moduleauthor:: Martin v. Löwis + +.. versionadded:: 2.3 + +This module implements :rfc:`3490` (Internationalized Domain Names in +Applications) and :rfc:`3492` (Nameprep: A Stringprep Profile for +Internationalized Domain Names (IDN)). It builds upon the ``punycode`` encoding +and :mod:`stringprep`. + +These RFCs together define a protocol to support non-ASCII characters in domain +names. A domain name containing non-ASCII characters (such as +``www.Alliancefrançaise.nu``) is converted into an ASCII-compatible encoding +(ACE, such as ``www.xn--alliancefranaise-npb.nu``). The ACE form of the domain +name is then used in all places where arbitrary characters are not allowed by +the protocol, such as DNS queries, HTTP :mailheader:`Host` fields, and so +on. This conversion is carried out in the application; if possible invisible to +the user: The application should transparently convert Unicode domain labels to +IDNA on the wire, and convert back ACE labels to Unicode before presenting them +to the user. + +Python supports this conversion in several ways: The ``idna`` codec allows to +convert between Unicode and the ACE. Furthermore, the :mod:`socket` module +transparently converts Unicode host names to ACE, so that applications need not +be concerned about converting host names themselves when they pass them to the +socket module. On top of that, modules that have host names as function +parameters, such as :mod:`httplib` and :mod:`ftplib`, accept Unicode host names +(:mod:`httplib` then also transparently sends an IDNA hostname in the +:mailheader:`Host` field if it sends that field at all). + +When receiving host names from the wire (such as in reverse name lookup), no +automatic conversion to Unicode is performed: Applications wishing to present +such host names to the user should decode them to Unicode. + +The module :mod:`encodings.idna` also implements the nameprep procedure, which +performs certain normalizations on host names, to achieve case-insensitivity of +international domain names, and to unify similar characters. The nameprep +functions can be used directly if desired. + + +.. function:: nameprep(label) + + Return the nameprepped version of *label*. The implementation currently assumes + query strings, so ``AllowUnassigned`` is true. + + +.. function:: ToASCII(label) + + Convert a label to ASCII, as specified in :rfc:`3490`. ``UseSTD3ASCIIRules`` is + assumed to be false. + + +.. function:: ToUnicode(label) + + Convert a label to Unicode, as specified in :rfc:`3490`. + + +:mod:`encodings.utf_8_sig` --- UTF-8 codec with BOM signature +------------------------------------------------------------- + +.. module:: encodings.utf_8_sig + :synopsis: UTF-8 codec with BOM signature +.. moduleauthor:: Walter Dörwald + +.. versionadded:: 2.5 + +This module implements a variant of the UTF-8 codec: On encoding a UTF-8 encoded +BOM will be prepended to the UTF-8 encoded bytes. For the stateful encoder this +is only done once (on the first write to the byte stream). For decoding an +optional UTF-8 encoded BOM at the start of the data will be skipped. + diff --git a/Doc/library/codeop.rst b/Doc/library/codeop.rst new file mode 100644 index 0000000..8a730ec --- /dev/null +++ b/Doc/library/codeop.rst @@ -0,0 +1,95 @@ + +:mod:`codeop` --- Compile Python code +===================================== + +.. module:: codeop + :synopsis: Compile (possibly incomplete) Python code. +.. sectionauthor:: Moshe Zadka +.. sectionauthor:: Michael Hudson + + +.. % LaTeXed from excellent doc-string. + +The :mod:`codeop` module provides utilities upon which the Python +read-eval-print loop can be emulated, as is done in the :mod:`code` module. As +a result, you probably don't want to use the module directly; if you want to +include such a loop in your program you probably want to use the :mod:`code` +module instead. + +There are two parts to this job: + +#. Being able to tell if a line of input completes a Python statement: in + short, telling whether to print '``>>>``' or '``...``' next. + +#. Remembering which future statements the user has entered, so subsequent + input can be compiled with these in effect. + +The :mod:`codeop` module provides a way of doing each of these things, and a way +of doing them both. + +To do just the former: + + +.. function:: compile_command(source[, filename[, symbol]]) + + Tries to compile *source*, which should be a string of Python code and return a + code object if *source* is valid Python code. In that case, the filename + attribute of the code object will be *filename*, which defaults to + ``''``. Returns ``None`` if *source* is *not* valid Python code, but is a + prefix of valid Python code. + + If there is a problem with *source*, an exception will be raised. + :exc:`SyntaxError` is raised if there is invalid Python syntax, and + :exc:`OverflowError` or :exc:`ValueError` if there is an invalid literal. + + The *symbol* argument determines whether *source* is compiled as a statement + (``'single'``, the default) or as an expression (``'eval'``). Any other value + will cause :exc:`ValueError` to be raised. + + **Caveat:** It is possible (but not likely) that the parser stops parsing with a + successful outcome before reaching the end of the source; in this case, trailing + symbols may be ignored instead of causing an error. For example, a backslash + followed by two newlines may be followed by arbitrary garbage. This will be + fixed once the API for the parser is better. + + +.. class:: Compile() + + Instances of this class have :meth:`__call__` methods identical in signature to + the built-in function :func:`compile`, but with the difference that if the + instance compiles program text containing a :mod:`__future__` statement, the + instance 'remembers' and compiles all subsequent program texts with the + statement in force. + + +.. class:: CommandCompiler() + + Instances of this class have :meth:`__call__` methods identical in signature to + :func:`compile_command`; the difference is that if the instance compiles program + text containing a ``__future__`` statement, the instance 'remembers' and + compiles all subsequent program texts with the statement in force. + +A note on version compatibility: the :class:`Compile` and +:class:`CommandCompiler` are new in Python 2.2. If you want to enable the +future-tracking features of 2.2 but also retain compatibility with 2.1 and +earlier versions of Python you can either write :: + + try: + from codeop import CommandCompiler + compile_command = CommandCompiler() + del CommandCompiler + except ImportError: + from codeop import compile_command + +which is a low-impact change, but introduces possibly unwanted global state into +your program, or you can write:: + + try: + from codeop import CommandCompiler + except ImportError: + def CommandCompiler(): + from codeop import compile_command + return compile_command + +and then call ``CommandCompiler`` every time you need a fresh compiler object. + diff --git a/Doc/library/collections.rst b/Doc/library/collections.rst new file mode 100644 index 0000000..c2c9262 --- /dev/null +++ b/Doc/library/collections.rst @@ -0,0 +1,414 @@ + +:mod:`collections` --- High-performance container datatypes +=========================================================== + +.. module:: collections + :synopsis: High-performance datatypes +.. moduleauthor:: Raymond Hettinger +.. sectionauthor:: Raymond Hettinger + + +.. versionadded:: 2.4 + +This module implements high-performance container datatypes. Currently, +there are two datatypes, :class:`deque` and :class:`defaultdict`, and +one datatype factory function, :func:`NamedTuple`. Python already +includes built-in containers, :class:`dict`, :class:`list`, +:class:`set`, and :class:`tuple`. In addition, the optional :mod:`bsddb` +module has a :meth:`bsddb.btopen` method that can be used to create in-memory +or file based ordered dictionaries with string keys. + +Future editions of the standard library may include balanced trees and +ordered dictionaries. + +.. versionchanged:: 2.5 + Added :class:`defaultdict`. + +.. versionchanged:: 2.6 + Added :class:`NamedTuple`. + + +.. _deque-objects: + +:class:`deque` objects +---------------------- + + +.. class:: deque([iterable]) + + Returns a new deque object initialized left-to-right (using :meth:`append`) with + data from *iterable*. If *iterable* is not specified, the new deque is empty. + + Deques are a generalization of stacks and queues (the name is pronounced "deck" + and is short for "double-ended queue"). Deques support thread-safe, memory + efficient appends and pops from either side of the deque with approximately the + same O(1) performance in either direction. + + Though :class:`list` objects support similar operations, they are optimized for + fast fixed-length operations and incur O(n) memory movement costs for + ``pop(0)`` and ``insert(0, v)`` operations which change both the size and + position of the underlying data representation. + + .. versionadded:: 2.4 + +Deque objects support the following methods: + + +.. method:: deque.append(x) + + Add *x* to the right side of the deque. + + +.. method:: deque.appendleft(x) + + Add *x* to the left side of the deque. + + +.. method:: deque.clear() + + Remove all elements from the deque leaving it with length 0. + + +.. method:: deque.extend(iterable) + + Extend the right side of the deque by appending elements from the iterable + argument. + + +.. method:: deque.extendleft(iterable) + + Extend the left side of the deque by appending elements from *iterable*. Note, + the series of left appends results in reversing the order of elements in the + iterable argument. + + +.. method:: deque.pop() + + Remove and return an element from the right side of the deque. If no elements + are present, raises an :exc:`IndexError`. + + +.. method:: deque.popleft() + + Remove and return an element from the left side of the deque. If no elements are + present, raises an :exc:`IndexError`. + + +.. method:: deque.remove(value) + + Removed the first occurrence of *value*. If not found, raises a + :exc:`ValueError`. + + .. versionadded:: 2.5 + + +.. method:: deque.rotate(n) + + Rotate the deque *n* steps to the right. If *n* is negative, rotate to the + left. Rotating one step to the right is equivalent to: + ``d.appendleft(d.pop())``. + +In addition to the above, deques support iteration, pickling, ``len(d)``, +``reversed(d)``, ``copy.copy(d)``, ``copy.deepcopy(d)``, membership testing with +the :keyword:`in` operator, and subscript references such as ``d[-1]``. + +Example:: + + >>> from collections import deque + >>> d = deque('ghi') # make a new deque with three items + >>> for elem in d: # iterate over the deque's elements + ... print elem.upper() + G + H + I + + >>> d.append('j') # add a new entry to the right side + >>> d.appendleft('f') # add a new entry to the left side + >>> d # show the representation of the deque + deque(['f', 'g', 'h', 'i', 'j']) + + >>> d.pop() # return and remove the rightmost item + 'j' + >>> d.popleft() # return and remove the leftmost item + 'f' + >>> list(d) # list the contents of the deque + ['g', 'h', 'i'] + >>> d[0] # peek at leftmost item + 'g' + >>> d[-1] # peek at rightmost item + 'i' + + >>> list(reversed(d)) # list the contents of a deque in reverse + ['i', 'h', 'g'] + >>> 'h' in d # search the deque + True + >>> d.extend('jkl') # add multiple elements at once + >>> d + deque(['g', 'h', 'i', 'j', 'k', 'l']) + >>> d.rotate(1) # right rotation + >>> d + deque(['l', 'g', 'h', 'i', 'j', 'k']) + >>> d.rotate(-1) # left rotation + >>> d + deque(['g', 'h', 'i', 'j', 'k', 'l']) + + >>> deque(reversed(d)) # make a new deque in reverse order + deque(['l', 'k', 'j', 'i', 'h', 'g']) + >>> d.clear() # empty the deque + >>> d.pop() # cannot pop from an empty deque + Traceback (most recent call last): + File "", line 1, in -toplevel- + d.pop() + IndexError: pop from an empty deque + + >>> d.extendleft('abc') # extendleft() reverses the input order + >>> d + deque(['c', 'b', 'a']) + + +.. _deque-recipes: + +Recipes +^^^^^^^ + +This section shows various approaches to working with deques. + +The :meth:`rotate` method provides a way to implement :class:`deque` slicing and +deletion. For example, a pure python implementation of ``del d[n]`` relies on +the :meth:`rotate` method to position elements to be popped:: + + def delete_nth(d, n): + d.rotate(-n) + d.popleft() + d.rotate(n) + +To implement :class:`deque` slicing, use a similar approach applying +:meth:`rotate` to bring a target element to the left side of the deque. Remove +old entries with :meth:`popleft`, add new entries with :meth:`extend`, and then +reverse the rotation. + +With minor variations on that approach, it is easy to implement Forth style +stack manipulations such as ``dup``, ``drop``, ``swap``, ``over``, ``pick``, +``rot``, and ``roll``. + +A roundrobin task server can be built from a :class:`deque` using +:meth:`popleft` to select the current task and :meth:`append` to add it back to +the tasklist if the input stream is not exhausted:: + + >>> def roundrobin(*iterables): + ... pending = deque(iter(i) for i in iterables) + ... while pending: + ... task = pending.popleft() + ... try: + ... yield next(task) + ... except StopIteration: + ... continue + ... pending.append(task) + ... + >>> for value in roundrobin('abc', 'd', 'efgh'): + ... print value + + a + d + e + b + f + c + g + h + + +Multi-pass data reduction algorithms can be succinctly expressed and efficiently +coded by extracting elements with multiple calls to :meth:`popleft`, applying +the reduction function, and calling :meth:`append` to add the result back to the +queue. + +For example, building a balanced binary tree of nested lists entails reducing +two adjacent nodes into one by grouping them in a list:: + + >>> def maketree(iterable): + ... d = deque(iterable) + ... while len(d) > 1: + ... pair = [d.popleft(), d.popleft()] + ... d.append(pair) + ... return list(d) + ... + >>> print maketree('abcdefgh') + [[[['a', 'b'], ['c', 'd']], [['e', 'f'], ['g', 'h']]]] + + + +.. _defaultdict-objects: + +:class:`defaultdict` objects +---------------------------- + + +.. class:: defaultdict([default_factory[, ...]]) + + Returns a new dictionary-like object. :class:`defaultdict` is a subclass of the + builtin :class:`dict` class. It overrides one method and adds one writable + instance variable. The remaining functionality is the same as for the + :class:`dict` class and is not documented here. + + The first argument provides the initial value for the :attr:`default_factory` + attribute; it defaults to ``None``. All remaining arguments are treated the same + as if they were passed to the :class:`dict` constructor, including keyword + arguments. + + .. versionadded:: 2.5 + +:class:`defaultdict` objects support the following method in addition to the +standard :class:`dict` operations: + + +.. method:: defaultdict.__missing__(key) + + If the :attr:`default_factory` attribute is ``None``, this raises an + :exc:`KeyError` exception with the *key* as argument. + + If :attr:`default_factory` is not ``None``, it is called without arguments to + provide a default value for the given *key*, this value is inserted in the + dictionary for the *key*, and returned. + + If calling :attr:`default_factory` raises an exception this exception is + propagated unchanged. + + This method is called by the :meth:`__getitem__` method of the :class:`dict` + class when the requested key is not found; whatever it returns or raises is then + returned or raised by :meth:`__getitem__`. + +:class:`defaultdict` objects support the following instance variable: + + +.. attribute:: defaultdict.default_factory + + This attribute is used by the :meth:`__missing__` method; it is initialized from + the first argument to the constructor, if present, or to ``None``, if absent. + + +.. _defaultdict-examples: + +:class:`defaultdict` Examples +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Using :class:`list` as the :attr:`default_factory`, it is easy to group a +sequence of key-value pairs into a dictionary of lists:: + + >>> s = [('yellow', 1), ('blue', 2), ('yellow', 3), ('blue', 4), ('red', 1)] + >>> d = defaultdict(list) + >>> for k, v in s: + ... d[k].append(v) + ... + >>> d.items() + [('blue', [2, 4]), ('red', [1]), ('yellow', [1, 3])] + +When each key is encountered for the first time, it is not already in the +mapping; so an entry is automatically created using the :attr:`default_factory` +function which returns an empty :class:`list`. The :meth:`list.append` +operation then attaches the value to the new list. When keys are encountered +again, the look-up proceeds normally (returning the list for that key) and the +:meth:`list.append` operation adds another value to the list. This technique is +simpler and faster than an equivalent technique using :meth:`dict.setdefault`:: + + >>> d = {} + >>> for k, v in s: + ... d.setdefault(k, []).append(v) + ... + >>> d.items() + [('blue', [2, 4]), ('red', [1]), ('yellow', [1, 3])] + +Setting the :attr:`default_factory` to :class:`int` makes the +:class:`defaultdict` useful for counting (like a bag or multiset in other +languages):: + + >>> s = 'mississippi' + >>> d = defaultdict(int) + >>> for k in s: + ... d[k] += 1 + ... + >>> d.items() + [('i', 4), ('p', 2), ('s', 4), ('m', 1)] + +When a letter is first encountered, it is missing from the mapping, so the +:attr:`default_factory` function calls :func:`int` to supply a default count of +zero. The increment operation then builds up the count for each letter. + +The function :func:`int` which always returns zero is just a special case of +constant functions. A faster and more flexible way to create constant functions +is to use a lambda function which can supply any constant value (not just +zero):: + + >>> def constant_factory(value): + ... return lambda: value + >>> d = defaultdict(constant_factory('')) + >>> d.update(name='John', action='ran') + >>> '%(name)s %(action)s to %(object)s' % d + 'John ran to ' + +Setting the :attr:`default_factory` to :class:`set` makes the +:class:`defaultdict` useful for building a dictionary of sets:: + + >>> s = [('red', 1), ('blue', 2), ('red', 3), ('blue', 4), ('red', 1), ('blue', 4)] + >>> d = defaultdict(set) + >>> for k, v in s: + ... d[k].add(v) + ... + >>> d.items() + [('blue', set([2, 4])), ('red', set([1, 3]))] + + +.. _named-tuple-factory: + +:func:`NamedTuple` datatype factory function +-------------------------------------------- + + +.. function:: NamedTuple(typename, fieldnames) + + Returns a new tuple subclass named *typename*. The new subclass is used to + create tuple-like objects that have fields accessable by attribute lookup as + well as being indexable and iterable. Instances of the subclass also have a + helpful docstring (with typename and fieldnames) and a helpful :meth:`__repr__` + method which lists the tuple contents in a ``name=value`` format. + + .. versionadded:: 2.6 + + The *fieldnames* are specified in a single string and are separated by spaces. + Any valid Python identifier may be used for a field name. + + Example:: + + >>> Point = NamedTuple('Point', 'x y') + >>> Point.__doc__ # docstring for the new datatype + 'Point(x, y)' + >>> p = Point(11, y=22) # instantiate with positional or keyword arguments + >>> p[0] + p[1] # works just like the tuple (11, 22) + 33 + >>> x, y = p # unpacks just like a tuple + >>> x, y + (11, 22) + >>> p.x + p.y # fields also accessable by name + 33 + >>> p # readable __repr__ with name=value style + Point(x=11, y=22) + + The use cases are the same as those for tuples. The named factories assign + meaning to each tuple position and allow for more readable, self-documenting + code. Named tuples can also be used to assign field names to tuples returned + by the :mod:`csv` or :mod:`sqlite3` modules. For example:: + + from itertools import starmap + import csv + EmployeeRecord = NamedTuple('EmployeeRecord', 'name age title department paygrade') + for record in starmap(EmployeeRecord, csv.reader(open("employees.csv", "rb"))): + print record + + To cast an individual record stored as :class:`list`, :class:`tuple`, or some + other iterable type, use the star-operator to unpack the values:: + + >>> Color = NamedTuple('Color', 'name code') + >>> m = dict(red=1, green=2, blue=3) + >>> print Color(*m.popitem()) + Color(name='blue', code=3) + diff --git a/Doc/library/colorpicker.rst b/Doc/library/colorpicker.rst new file mode 100644 index 0000000..4244104 --- /dev/null +++ b/Doc/library/colorpicker.rst @@ -0,0 +1,23 @@ + +:mod:`ColorPicker` --- Color selection dialog +============================================= + +.. module:: ColorPicker + :platform: Mac + :synopsis: Interface to the standard color selection dialog. +.. moduleauthor:: Just van Rossum +.. sectionauthor:: Fred L. Drake, Jr. + + +The :mod:`ColorPicker` module provides access to the standard color picker +dialog. + + +.. function:: GetColor(prompt, rgb) + + Show a standard color selection dialog and allow the user to select a color. + The user is given instruction by the *prompt* string, and the default color is + set to *rgb*. *rgb* must be a tuple giving the red, green, and blue components + of the color. :func:`GetColor` returns a tuple giving the user's selected color + and a flag indicating whether they accepted the selection of cancelled. + diff --git a/Doc/library/colorsys.rst b/Doc/library/colorsys.rst new file mode 100644 index 0000000..2e7f3b7 --- /dev/null +++ b/Doc/library/colorsys.rst @@ -0,0 +1,60 @@ + +:mod:`colorsys` --- Conversions between color systems +===================================================== + +.. module:: colorsys + :synopsis: Conversion functions between RGB and other color systems. +.. sectionauthor:: David Ascher + + +The :mod:`colorsys` module defines bidirectional conversions of color values +between colors expressed in the RGB (Red Green Blue) color space used in +computer monitors and three other coordinate systems: YIQ, HLS (Hue Lightness +Saturation) and HSV (Hue Saturation Value). Coordinates in all of these color +spaces are floating point values. In the YIQ space, the Y coordinate is between +0 and 1, but the I and Q coordinates can be positive or negative. In all other +spaces, the coordinates are all between 0 and 1. + +More information about color spaces can be found at +http://www.poynton.com/ColorFAQ.html. + +The :mod:`colorsys` module defines the following functions: + + +.. function:: rgb_to_yiq(r, g, b) + + Convert the color from RGB coordinates to YIQ coordinates. + + +.. function:: yiq_to_rgb(y, i, q) + + Convert the color from YIQ coordinates to RGB coordinates. + + +.. function:: rgb_to_hls(r, g, b) + + Convert the color from RGB coordinates to HLS coordinates. + + +.. function:: hls_to_rgb(h, l, s) + + Convert the color from HLS coordinates to RGB coordinates. + + +.. function:: rgb_to_hsv(r, g, b) + + Convert the color from RGB coordinates to HSV coordinates. + + +.. function:: hsv_to_rgb(h, s, v) + + Convert the color from HSV coordinates to RGB coordinates. + +Example:: + + >>> import colorsys + >>> colorsys.rgb_to_hsv(.3, .4, .2) + (0.25, 0.5, 0.4) + >>> colorsys.hsv_to_rgb(0.25, 0.5, 0.4) + (0.3, 0.4, 0.2) + diff --git a/Doc/library/commands.rst b/Doc/library/commands.rst new file mode 100644 index 0000000..79e3d73 --- /dev/null +++ b/Doc/library/commands.rst @@ -0,0 +1,53 @@ + +:mod:`commands` --- Utilities for running commands +================================================== + +.. module:: commands + :platform: Unix + :synopsis: Utility functions for running external commands. +.. sectionauthor:: Sue Williams + + +The :mod:`commands` module contains wrapper functions for :func:`os.popen` which +take a system command as a string and return any output generated by the command +and, optionally, the exit status. + +The :mod:`subprocess` module provides more powerful facilities for spawning new +processes and retrieving their results. Using the :mod:`subprocess` module is +preferable to using the :mod:`commands` module. + +The :mod:`commands` module defines the following functions: + + +.. function:: getstatusoutput(cmd) + + Execute the string *cmd* in a shell with :func:`os.popen` and return a 2-tuple + ``(status, output)``. *cmd* is actually run as ``{ cmd ; } 2>&1``, so that the + returned output will contain output or error messages. A trailing newline is + stripped from the output. The exit status for the command can be interpreted + according to the rules for the C function :cfunc:`wait`. + + +.. function:: getoutput(cmd) + + Like :func:`getstatusoutput`, except the exit status is ignored and the return + value is a string containing the command's output. + +Example:: + + >>> import commands + >>> commands.getstatusoutput('ls /bin/ls') + (0, '/bin/ls') + >>> commands.getstatusoutput('cat /bin/junk') + (256, 'cat: /bin/junk: No such file or directory') + >>> commands.getstatusoutput('/bin/junk') + (256, 'sh: /bin/junk: not found') + >>> commands.getoutput('ls /bin/ls') + '/bin/ls' + + +.. seealso:: + + Module :mod:`subprocess` + Module for spawning and managing subprocesses. + diff --git a/Doc/library/compileall.rst b/Doc/library/compileall.rst new file mode 100644 index 0000000..d62b785 --- /dev/null +++ b/Doc/library/compileall.rst @@ -0,0 +1,57 @@ + +:mod:`compileall` --- Byte-compile Python libraries +=================================================== + +.. module:: compileall + :synopsis: Tools for byte-compiling all Python source files in a directory tree. + + +This module provides some utility functions to support installing Python +libraries. These functions compile Python source files in a directory tree, +allowing users without permission to write to the libraries to take advantage of +cached byte-code files. + +The source file for this module may also be used as a script to compile Python +sources in directories named on the command line or in ``sys.path``. + + +.. function:: compile_dir(dir[, maxlevels[, ddir[, force[, rx[, quiet]]]]]) + + Recursively descend the directory tree named by *dir*, compiling all :file:`.py` + files along the way. The *maxlevels* parameter is used to limit the depth of + the recursion; it defaults to ``10``. If *ddir* is given, it is used as the + base path from which the filenames used in error messages will be generated. + If *force* is true, modules are re-compiled even if the timestamps are up to + date. + + If *rx* is given, it specifies a regular expression of file names to exclude + from the search; that expression is searched for in the full path. + + If *quiet* is true, nothing is printed to the standard output in normal + operation. + + +.. function:: compile_path([skip_curdir[, maxlevels[, force]]]) + + Byte-compile all the :file:`.py` files found along ``sys.path``. If + *skip_curdir* is true (the default), the current directory is not included in + the search. The *maxlevels* and *force* parameters default to ``0`` and are + passed to the :func:`compile_dir` function. + +To force a recompile of all the :file:`.py` files in the :file:`Lib/` +subdirectory and all its subdirectories:: + + import compileall + + compileall.compile_dir('Lib/', force=True) + + # Perform same compilation, excluding files in .svn directories. + import re + compileall.compile_dir('Lib/', rx=re.compile('/[.]svn'), force=True) + + +.. seealso:: + + Module :mod:`py_compile` + Byte-compile a single source file. + diff --git a/Doc/library/configparser.rst b/Doc/library/configparser.rst new file mode 100644 index 0000000..dd91d59 --- /dev/null +++ b/Doc/library/configparser.rst @@ -0,0 +1,361 @@ + +:mod:`ConfigParser` --- Configuration file parser +================================================= + +.. module:: ConfigParser + :synopsis: Configuration file parser. +.. moduleauthor:: Ken Manheimer +.. moduleauthor:: Barry Warsaw +.. moduleauthor:: Eric S. Raymond +.. sectionauthor:: Christopher G. Petrilli + + +.. index:: + pair: .ini; file + pair: configuration; file + single: ini file + single: Windows ini file + +This module defines the class :class:`ConfigParser`. The :class:`ConfigParser` +class implements a basic configuration file parser language which provides a +structure similar to what you would find on Microsoft Windows INI files. You +can use this to write Python programs which can be customized by end users +easily. + +.. warning:: + + This library does *not* interpret or write the value-type prefixes used in the + Windows Registry extended version of INI syntax. + +The configuration file consists of sections, led by a ``[section]`` header and +followed by ``name: value`` entries, with continuations in the style of +:rfc:`822`; ``name=value`` is also accepted. Note that leading whitespace is +removed from values. The optional values can contain format strings which refer +to other values in the same section, or values in a special ``DEFAULT`` section. +Additional defaults can be provided on initialization and retrieval. Lines +beginning with ``'#'`` or ``';'`` are ignored and may be used to provide +comments. + +For example:: + + [My Section] + foodir: %(dir)s/whatever + dir=frob + +would resolve the ``%(dir)s`` to the value of ``dir`` (``frob`` in this case). +All reference expansions are done on demand. + +Default values can be specified by passing them into the :class:`ConfigParser` +constructor as a dictionary. Additional defaults may be passed into the +:meth:`get` method which will override all others. + +Sections are normally stored in a builtin dictionary. An alternative dictionary +type can be passed to the :class:`ConfigParser` constructor. For example, if a +dictionary type is passed that sorts its keys, the sections will be sorted on +write-back, as will be the keys within each section. + + +.. class:: RawConfigParser([defaults[, dict_type]]) + + The basic configuration object. When *defaults* is given, it is initialized + into the dictionary of intrinsic defaults. When *dict_type* is given, it will + be used to create the dictionary objects for the list of sections, for the + options within a section, and for the default values. This class does not + support the magical interpolation behavior. + + .. versionadded:: 2.3 + + .. versionchanged:: 2.6 + *dict_type* was added. + + +.. class:: ConfigParser([defaults]) + + Derived class of :class:`RawConfigParser` that implements the magical + interpolation feature and adds optional arguments to the :meth:`get` and + :meth:`items` methods. The values in *defaults* must be appropriate for the + ``%()s`` string interpolation. Note that *__name__* is an intrinsic default; + its value is the section name, and will override any value provided in + *defaults*. + + All option names used in interpolation will be passed through the + :meth:`optionxform` method just like any other option name reference. For + example, using the default implementation of :meth:`optionxform` (which converts + option names to lower case), the values ``foo %(bar)s`` and ``foo %(BAR)s`` are + equivalent. + + +.. class:: SafeConfigParser([defaults]) + + Derived class of :class:`ConfigParser` that implements a more-sane variant of + the magical interpolation feature. This implementation is more predictable as + well. New applications should prefer this version if they don't need to be + compatible with older versions of Python. + + .. % XXX Need to explain what's safer/more predictable about it. + + .. versionadded:: 2.3 + + +.. exception:: NoSectionError + + Exception raised when a specified section is not found. + + +.. exception:: DuplicateSectionError + + Exception raised if :meth:`add_section` is called with the name of a section + that is already present. + + +.. exception:: NoOptionError + + Exception raised when a specified option is not found in the specified section. + + +.. exception:: InterpolationError + + Base class for exceptions raised when problems occur performing string + interpolation. + + +.. exception:: InterpolationDepthError + + Exception raised when string interpolation cannot be completed because the + number of iterations exceeds :const:`MAX_INTERPOLATION_DEPTH`. Subclass of + :exc:`InterpolationError`. + + +.. exception:: InterpolationMissingOptionError + + Exception raised when an option referenced from a value does not exist. Subclass + of :exc:`InterpolationError`. + + .. versionadded:: 2.3 + + +.. exception:: InterpolationSyntaxError + + Exception raised when the source text into which substitutions are made does not + conform to the required syntax. Subclass of :exc:`InterpolationError`. + + .. versionadded:: 2.3 + + +.. exception:: MissingSectionHeaderError + + Exception raised when attempting to parse a file which has no section headers. + + +.. exception:: ParsingError + + Exception raised when errors occur attempting to parse a file. + + +.. data:: MAX_INTERPOLATION_DEPTH + + The maximum depth for recursive interpolation for :meth:`get` when the *raw* + parameter is false. This is relevant only for the :class:`ConfigParser` class. + + +.. seealso:: + + Module :mod:`shlex` + Support for a creating Unix shell-like mini-languages which can be used as an + alternate format for application configuration files. + + +.. _rawconfigparser-objects: + +RawConfigParser Objects +----------------------- + +:class:`RawConfigParser` instances have the following methods: + + +.. method:: RawConfigParser.defaults() + + Return a dictionary containing the instance-wide defaults. + + +.. method:: RawConfigParser.sections() + + Return a list of the sections available; ``DEFAULT`` is not included in the + list. + + +.. method:: RawConfigParser.add_section(section) + + Add a section named *section* to the instance. If a section by the given name + already exists, :exc:`DuplicateSectionError` is raised. + + +.. method:: RawConfigParser.has_section(section) + + Indicates whether the named section is present in the configuration. The + ``DEFAULT`` section is not acknowledged. + + +.. method:: RawConfigParser.options(section) + + Returns a list of options available in the specified *section*. + + +.. method:: RawConfigParser.has_option(section, option) + + If the given section exists, and contains the given option, return + :const:`True`; otherwise return :const:`False`. + + .. versionadded:: 1.6 + + +.. method:: RawConfigParser.read(filenames) + + Attempt to read and parse a list of filenames, returning a list of filenames + which were successfully parsed. If *filenames* is a string or Unicode string, + it is treated as a single filename. If a file named in *filenames* cannot be + opened, that file will be ignored. This is designed so that you can specify a + list of potential configuration file locations (for example, the current + directory, the user's home directory, and some system-wide directory), and all + existing configuration files in the list will be read. If none of the named + files exist, the :class:`ConfigParser` instance will contain an empty dataset. + An application which requires initial values to be loaded from a file should + load the required file or files using :meth:`readfp` before calling :meth:`read` + for any optional files:: + + import ConfigParser, os + + config = ConfigParser.ConfigParser() + config.readfp(open('defaults.cfg')) + config.read(['site.cfg', os.path.expanduser('~/.myapp.cfg')]) + + .. versionchanged:: 2.4 + Returns list of successfully parsed filenames. + + +.. method:: RawConfigParser.readfp(fp[, filename]) + + Read and parse configuration data from the file or file-like object in *fp* + (only the :meth:`readline` method is used). If *filename* is omitted and *fp* + has a :attr:`name` attribute, that is used for *filename*; the default is + ````. + + +.. method:: RawConfigParser.get(section, option) + + Get an *option* value for the named *section*. + + +.. method:: RawConfigParser.getint(section, option) + + A convenience method which coerces the *option* in the specified *section* to an + integer. + + +.. method:: RawConfigParser.getfloat(section, option) + + A convenience method which coerces the *option* in the specified *section* to a + floating point number. + + +.. method:: RawConfigParser.getboolean(section, option) + + A convenience method which coerces the *option* in the specified *section* to a + Boolean value. Note that the accepted values for the option are ``"1"``, + ``"yes"``, ``"true"``, and ``"on"``, which cause this method to return ``True``, + and ``"0"``, ``"no"``, ``"false"``, and ``"off"``, which cause it to return + ``False``. These string values are checked in a case-insensitive manner. Any + other value will cause it to raise :exc:`ValueError`. + + +.. method:: RawConfigParser.items(section) + + Return a list of ``(name, value)`` pairs for each option in the given *section*. + + +.. method:: RawConfigParser.set(section, option, value) + + If the given section exists, set the given option to the specified value; + otherwise raise :exc:`NoSectionError`. While it is possible to use + :class:`RawConfigParser` (or :class:`ConfigParser` with *raw* parameters set to + true) for *internal* storage of non-string values, full functionality (including + interpolation and output to files) can only be achieved using string values. + + .. versionadded:: 1.6 + + +.. method:: RawConfigParser.write(fileobject) + + Write a representation of the configuration to the specified file object. This + representation can be parsed by a future :meth:`read` call. + + .. versionadded:: 1.6 + + +.. method:: RawConfigParser.remove_option(section, option) + + Remove the specified *option* from the specified *section*. If the section does + not exist, raise :exc:`NoSectionError`. If the option existed to be removed, + return :const:`True`; otherwise return :const:`False`. + + .. versionadded:: 1.6 + + +.. method:: RawConfigParser.remove_section(section) + + Remove the specified *section* from the configuration. If the section in fact + existed, return ``True``. Otherwise return ``False``. + + +.. method:: RawConfigParser.optionxform(option) + + Transforms the option name *option* as found in an input file or as passed in by + client code to the form that should be used in the internal structures. The + default implementation returns a lower-case version of *option*; subclasses may + override this or client code can set an attribute of this name on instances to + affect this behavior. Setting this to :func:`str`, for example, would make + option names case sensitive. + + +.. _configparser-objects: + +ConfigParser Objects +-------------------- + +The :class:`ConfigParser` class extends some methods of the +:class:`RawConfigParser` interface, adding some optional arguments. + + +.. method:: ConfigParser.get(section, option[, raw[, vars]]) + + Get an *option* value for the named *section*. All the ``'%'`` interpolations + are expanded in the return values, based on the defaults passed into the + constructor, as well as the options *vars* provided, unless the *raw* argument + is true. + + +.. method:: ConfigParser.items(section[, raw[, vars]]) + + Return a list of ``(name, value)`` pairs for each option in the given *section*. + Optional arguments have the same meaning as for the :meth:`get` method. + + .. versionadded:: 2.3 + + +.. _safeconfigparser-objects: + +SafeConfigParser Objects +------------------------ + +The :class:`SafeConfigParser` class implements the same extended interface as +:class:`ConfigParser`, with the following addition: + + +.. method:: SafeConfigParser.set(section, option, value) + + If the given section exists, set the given option to the specified value; + otherwise raise :exc:`NoSectionError`. *value* must be a string (:class:`str` + or :class:`unicode`); if not, :exc:`TypeError` is raised. + + .. versionadded:: 2.4 + diff --git a/Doc/library/constants.rst b/Doc/library/constants.rst new file mode 100644 index 0000000..fecd836 --- /dev/null +++ b/Doc/library/constants.rst @@ -0,0 +1,42 @@ + +Built-in Constants +================== + +A small number of constants live in the built-in namespace. They are: + + +.. data:: False + + The false value of the :class:`bool` type. + + .. versionadded:: 2.3 + + +.. data:: True + + The true value of the :class:`bool` type. + + .. versionadded:: 2.3 + + +.. data:: None + + The sole value of :attr:`types.NoneType`. ``None`` is frequently used to + represent the absence of a value, as when default arguments are not passed to a + function. + + +.. data:: NotImplemented + + Special value which can be returned by the "rich comparison" special methods + (:meth:`__eq__`, :meth:`__lt__`, and friends), to indicate that the comparison + is not implemented with respect to the other type. + + +.. data:: Ellipsis + + The same as ``...``. Special value used mostly in conjunction with extended + slicing syntax for user-defined container data types. + + .. % XXX Someone who understands extended slicing should fill in here. + diff --git a/Doc/library/contextlib.rst b/Doc/library/contextlib.rst new file mode 100644 index 0000000..fffb99c --- /dev/null +++ b/Doc/library/contextlib.rst @@ -0,0 +1,120 @@ + +:mod:`contextlib` --- Utilities for :keyword:`with`\ -statement contexts. +========================================================================= + +.. module:: contextlib + :synopsis: Utilities for with-statement contexts. + + +.. versionadded:: 2.5 + +This module provides utilities for common tasks involving the :keyword:`with` +statement. For more information see also :ref:`typecontextmanager` and +:ref:`context-managers`. + +Functions provided: + + +.. function:: contextmanager(func) + + This function is a decorator that can be used to define a factory function for + :keyword:`with` statement context managers, without needing to create a class or + separate :meth:`__enter__` and :meth:`__exit__` methods. + + A simple example (this is not recommended as a real way of generating HTML!):: + + from __future__ import with_statement + from contextlib import contextmanager + + @contextmanager + def tag(name): + print "<%s>" % name + yield + print "" % name + + >>> with tag("h1"): + ... print "foo" + ... +

    + foo +

    + + The function being decorated must return a generator-iterator when called. This + iterator must yield exactly one value, which will be bound to the targets in the + :keyword:`with` statement's :keyword:`as` clause, if any. + + At the point where the generator yields, the block nested in the :keyword:`with` + statement is executed. The generator is then resumed after the block is exited. + If an unhandled exception occurs in the block, it is reraised inside the + generator at the point where the yield occurred. Thus, you can use a + :keyword:`try`...\ :keyword:`except`...\ :keyword:`finally` statement to trap + the error (if any), or ensure that some cleanup takes place. If an exception is + trapped merely in order to log it or to perform some action (rather than to + suppress it entirely), the generator must reraise that exception. Otherwise the + generator context manager will indicate to the :keyword:`with` statement that + the exception has been handled, and execution will resume with the statement + immediately following the :keyword:`with` statement. + + +.. function:: nested(mgr1[, mgr2[, ...]]) + + Combine multiple context managers into a single nested context manager. + + Code like this:: + + from contextlib import nested + + with nested(A, B, C) as (X, Y, Z): + do_something() + + is equivalent to this:: + + with A as X: + with B as Y: + with C as Z: + do_something() + + Note that if the :meth:`__exit__` method of one of the nested context managers + indicates an exception should be suppressed, no exception information will be + passed to any remaining outer context managers. Similarly, if the + :meth:`__exit__` method of one of the nested managers raises an exception, any + previous exception state will be lost; the new exception will be passed to the + :meth:`__exit__` methods of any remaining outer context managers. In general, + :meth:`__exit__` methods should avoid raising exceptions, and in particular they + should not re-raise a passed-in exception. + + +.. function:: closing(thing) + + Return a context manager that closes *thing* upon completion of the block. This + is basically equivalent to:: + + from contextlib import contextmanager + + @contextmanager + def closing(thing): + try: + yield thing + finally: + thing.close() + + And lets you write code like this:: + + from __future__ import with_statement + from contextlib import closing + import urllib + + with closing(urllib.urlopen('http://www.python.org')) as page: + for line in page: + print line + + without needing to explicitly close ``page``. Even if an error occurs, + ``page.close()`` will be called when the :keyword:`with` block is exited. + + +.. seealso:: + + :pep:`0343` - The "with" statement + The specification, background, and examples for the Python :keyword:`with` + statement. + diff --git a/Doc/library/cookie.rst b/Doc/library/cookie.rst new file mode 100644 index 0000000..5a5808f --- /dev/null +++ b/Doc/library/cookie.rst @@ -0,0 +1,282 @@ + +:mod:`Cookie` --- HTTP state management +======================================= + +.. module:: Cookie + :synopsis: Support for HTTP state management (cookies). +.. moduleauthor:: Timothy O'Malley +.. sectionauthor:: Moshe Zadka + + +The :mod:`Cookie` module defines classes for abstracting the concept of +cookies, an HTTP state management mechanism. It supports both simple string-only +cookies, and provides an abstraction for having any serializable data-type as +cookie value. + +The module formerly strictly applied the parsing rules described in the +:rfc:`2109` and :rfc:`2068` specifications. It has since been discovered that +MSIE 3.0x doesn't follow the character rules outlined in those specs. As a +result, the parsing rules used are a bit less strict. + + +.. exception:: CookieError + + Exception failing because of :rfc:`2109` invalidity: incorrect attributes, + incorrect :mailheader:`Set-Cookie` header, etc. + + +.. class:: BaseCookie([input]) + + This class is a dictionary-like object whose keys are strings and whose values + are :class:`Morsel` instances. Note that upon setting a key to a value, the + value is first converted to a :class:`Morsel` containing the key and the value. + + If *input* is given, it is passed to the :meth:`load` method. + + +.. class:: SimpleCookie([input]) + + This class derives from :class:`BaseCookie` and overrides :meth:`value_decode` + and :meth:`value_encode` to be the identity and :func:`str` respectively. + + +.. class:: SerialCookie([input]) + + This class derives from :class:`BaseCookie` and overrides :meth:`value_decode` + and :meth:`value_encode` to be the :func:`pickle.loads` and + :func:`pickle.dumps`. + + .. deprecated:: 2.3 + Reading pickled values from untrusted cookie data is a huge security hole, as + pickle strings can be crafted to cause arbitrary code to execute on your server. + It is supported for backwards compatibility only, and may eventually go away. + + +.. class:: SmartCookie([input]) + + This class derives from :class:`BaseCookie`. It overrides :meth:`value_decode` + to be :func:`pickle.loads` if it is a valid pickle, and otherwise the value + itself. It overrides :meth:`value_encode` to be :func:`pickle.dumps` unless it + is a string, in which case it returns the value itself. + + .. deprecated:: 2.3 + The same security warning from :class:`SerialCookie` applies here. + +A further security note is warranted. For backwards compatibility, the +:mod:`Cookie` module exports a class named :class:`Cookie` which is just an +alias for :class:`SmartCookie`. This is probably a mistake and will likely be +removed in a future version. You should not use the :class:`Cookie` class in +your applications, for the same reason why you should not use the +:class:`SerialCookie` class. + + +.. seealso:: + + Module :mod:`cookielib` + HTTP cookie handling for web *clients*. The :mod:`cookielib` and :mod:`Cookie` + modules do not depend on each other. + + :rfc:`2109` - HTTP State Management Mechanism + This is the state management specification implemented by this module. + + +.. _cookie-objects: + +Cookie Objects +-------------- + + +.. method:: BaseCookie.value_decode(val) + + Return a decoded value from a string representation. Return value can be any + type. This method does nothing in :class:`BaseCookie` --- it exists so it can be + overridden. + + +.. method:: BaseCookie.value_encode(val) + + Return an encoded value. *val* can be any type, but return value must be a + string. This method does nothing in :class:`BaseCookie` --- it exists so it can + be overridden + + In general, it should be the case that :meth:`value_encode` and + :meth:`value_decode` are inverses on the range of *value_decode*. + + +.. method:: BaseCookie.output([attrs[, header[, sep]]]) + + Return a string representation suitable to be sent as HTTP headers. *attrs* and + *header* are sent to each :class:`Morsel`'s :meth:`output` method. *sep* is used + to join the headers together, and is by default the combination ``'\r\n'`` + (CRLF). + + .. versionchanged:: 2.5 + The default separator has been changed from ``'\n'`` to match the cookie + specification. + + +.. method:: BaseCookie.js_output([attrs]) + + Return an embeddable JavaScript snippet, which, if run on a browser which + supports JavaScript, will act the same as if the HTTP headers was sent. + + The meaning for *attrs* is the same as in :meth:`output`. + + +.. method:: BaseCookie.load(rawdata) + + If *rawdata* is a string, parse it as an ``HTTP_COOKIE`` and add the values + found there as :class:`Morsel`\ s. If it is a dictionary, it is equivalent to:: + + for k, v in rawdata.items(): + cookie[k] = v + + +.. _morsel-objects: + +Morsel Objects +-------------- + + +.. class:: Morsel() + + Abstract a key/value pair, which has some :rfc:`2109` attributes. + + Morsels are dictionary-like objects, whose set of keys is constant --- the valid + :rfc:`2109` attributes, which are + + * ``expires`` + * ``path`` + * ``comment`` + * ``domain`` + * ``max-age`` + * ``secure`` + * ``version`` + + The keys are case-insensitive. + + +.. attribute:: Morsel.value + + The value of the cookie. + + +.. attribute:: Morsel.coded_value + + The encoded value of the cookie --- this is what should be sent. + + +.. attribute:: Morsel.key + + The name of the cookie. + + +.. method:: Morsel.set(key, value, coded_value) + + Set the *key*, *value* and *coded_value* members. + + +.. method:: Morsel.isReservedKey(K) + + Whether *K* is a member of the set of keys of a :class:`Morsel`. + + +.. method:: Morsel.output([attrs[, header]]) + + Return a string representation of the Morsel, suitable to be sent as an HTTP + header. By default, all the attributes are included, unless *attrs* is given, in + which case it should be a list of attributes to use. *header* is by default + ``"Set-Cookie:"``. + + +.. method:: Morsel.js_output([attrs]) + + Return an embeddable JavaScript snippet, which, if run on a browser which + supports JavaScript, will act the same as if the HTTP header was sent. + + The meaning for *attrs* is the same as in :meth:`output`. + + +.. method:: Morsel.OutputString([attrs]) + + Return a string representing the Morsel, without any surrounding HTTP or + JavaScript. + + The meaning for *attrs* is the same as in :meth:`output`. + + +.. _cookie-example: + +Example +------- + +The following example demonstrates how to use the :mod:`Cookie` module. :: + + >>> import Cookie + >>> C = Cookie.SimpleCookie() + >>> C = Cookie.SerialCookie() + >>> C = Cookie.SmartCookie() + >>> C["fig"] = "newton" + >>> C["sugar"] = "wafer" + >>> print C # generate HTTP headers + Set-Cookie: sugar=wafer + Set-Cookie: fig=newton + >>> print C.output() # same thing + Set-Cookie: sugar=wafer + Set-Cookie: fig=newton + >>> C = Cookie.SmartCookie() + >>> C["rocky"] = "road" + >>> C["rocky"]["path"] = "/cookie" + >>> print C.output(header="Cookie:") + Cookie: rocky=road; Path=/cookie + >>> print C.output(attrs=[], header="Cookie:") + Cookie: rocky=road + >>> C = Cookie.SmartCookie() + >>> C.load("chips=ahoy; vienna=finger") # load from a string (HTTP header) + >>> print C + Set-Cookie: vienna=finger + Set-Cookie: chips=ahoy + >>> C = Cookie.SmartCookie() + >>> C.load('keebler="E=everybody; L=\\"Loves\\"; fudge=\\012;";') + >>> print C + Set-Cookie: keebler="E=everybody; L=\"Loves\"; fudge=\012;" + >>> C = Cookie.SmartCookie() + >>> C["oreo"] = "doublestuff" + >>> C["oreo"]["path"] = "/" + >>> print C + Set-Cookie: oreo=doublestuff; Path=/ + >>> C = Cookie.SmartCookie() + >>> C["twix"] = "none for you" + >>> C["twix"].value + 'none for you' + >>> C = Cookie.SimpleCookie() + >>> C["number"] = 7 # equivalent to C["number"] = str(7) + >>> C["string"] = "seven" + >>> C["number"].value + '7' + >>> C["string"].value + 'seven' + >>> print C + Set-Cookie: number=7 + Set-Cookie: string=seven + >>> C = Cookie.SerialCookie() + >>> C["number"] = 7 + >>> C["string"] = "seven" + >>> C["number"].value + 7 + >>> C["string"].value + 'seven' + >>> print C + Set-Cookie: number="I7\012." + Set-Cookie: string="S'seven'\012p1\012." + >>> C = Cookie.SmartCookie() + >>> C["number"] = 7 + >>> C["string"] = "seven" + >>> C["number"].value + 7 + >>> C["string"].value + 'seven' + >>> print C + Set-Cookie: number="I7\012." + Set-Cookie: string=seven + diff --git a/Doc/library/cookielib.rst b/Doc/library/cookielib.rst new file mode 100644 index 0000000..44045d3 --- /dev/null +++ b/Doc/library/cookielib.rst @@ -0,0 +1,768 @@ + +:mod:`cookielib` --- Cookie handling for HTTP clients +===================================================== + +.. module:: cookielib + :synopsis: Classes for automatic handling of HTTP cookies. +.. moduleauthor:: John J. Lee +.. sectionauthor:: John J. Lee + + +.. versionadded:: 2.4 + + + +The :mod:`cookielib` module defines classes for automatic handling of HTTP +cookies. It is useful for accessing web sites that require small pieces of data +-- :dfn:`cookies` -- to be set on the client machine by an HTTP response from a +web server, and then returned to the server in later HTTP requests. + +Both the regular Netscape cookie protocol and the protocol defined by +:rfc:`2965` are handled. RFC 2965 handling is switched off by default. +:rfc:`2109` cookies are parsed as Netscape cookies and subsequently treated +either as Netscape or RFC 2965 cookies according to the 'policy' in effect. +Note that the great majority of cookies on the Internet are Netscape cookies. +:mod:`cookielib` attempts to follow the de-facto Netscape cookie protocol (which +differs substantially from that set out in the original Netscape specification), +including taking note of the ``max-age`` and ``port`` cookie-attributes +introduced with RFC 2965. + +.. note:: + + The various named parameters found in :mailheader:`Set-Cookie` and + :mailheader:`Set-Cookie2` headers (eg. ``domain`` and ``expires``) are + conventionally referred to as :dfn:`attributes`. To distinguish them from + Python attributes, the documentation for this module uses the term + :dfn:`cookie-attribute` instead. + + +The module defines the following exception: + + +.. exception:: LoadError + + Instances of :class:`FileCookieJar` raise this exception on failure to load + cookies from a file. + + .. note:: + + For backwards-compatibility with Python 2.4 (which raised an :exc:`IOError`), + :exc:`LoadError` is a subclass of :exc:`IOError`. + + +The following classes are provided: + + +.. class:: CookieJar(policy=None) + + *policy* is an object implementing the :class:`CookiePolicy` interface. + + The :class:`CookieJar` class stores HTTP cookies. It extracts cookies from HTTP + requests, and returns them in HTTP responses. :class:`CookieJar` instances + automatically expire contained cookies when necessary. Subclasses are also + responsible for storing and retrieving cookies from a file or database. + + +.. class:: FileCookieJar(filename, delayload=None, policy=None) + + *policy* is an object implementing the :class:`CookiePolicy` interface. For the + other arguments, see the documentation for the corresponding attributes. + + A :class:`CookieJar` which can load cookies from, and perhaps save cookies to, a + file on disk. Cookies are **NOT** loaded from the named file until either the + :meth:`load` or :meth:`revert` method is called. Subclasses of this class are + documented in section :ref:`file-cookie-jar-classes`. + + +.. class:: CookiePolicy() + + This class is responsible for deciding whether each cookie should be accepted + from / returned to the server. + + +.. class:: DefaultCookiePolicy( blocked_domains=None, allowed_domains=None, netscape=True, rfc2965=False, rfc2109_as_netscape=None, hide_cookie2=False, strict_domain=False, strict_rfc2965_unverifiable=True, strict_ns_unverifiable=False, strict_ns_domain=DefaultCookiePolicy.DomainLiberal, strict_ns_set_initial_dollar=False, strict_ns_set_path=False ) + + Constructor arguments should be passed as keyword arguments only. + *blocked_domains* is a sequence of domain names that we never accept cookies + from, nor return cookies to. *allowed_domains* if not :const:`None`, this is a + sequence of the only domains for which we accept and return cookies. For all + other arguments, see the documentation for :class:`CookiePolicy` and + :class:`DefaultCookiePolicy` objects. + + :class:`DefaultCookiePolicy` implements the standard accept / reject rules for + Netscape and RFC 2965 cookies. By default, RFC 2109 cookies (ie. cookies + received in a :mailheader:`Set-Cookie` header with a version cookie-attribute of + 1) are treated according to the RFC 2965 rules. However, if RFC 2965 handling + is turned off or :attr:`rfc2109_as_netscape` is True, RFC 2109 cookies are + 'downgraded' by the :class:`CookieJar` instance to Netscape cookies, by + setting the :attr:`version` attribute of the :class:`Cookie` instance to 0. + :class:`DefaultCookiePolicy` also provides some parameters to allow some + fine-tuning of policy. + + +.. class:: Cookie() + + This class represents Netscape, RFC 2109 and RFC 2965 cookies. It is not + expected that users of :mod:`cookielib` construct their own :class:`Cookie` + instances. Instead, if necessary, call :meth:`make_cookies` on a + :class:`CookieJar` instance. + + +.. seealso:: + + Module :mod:`urllib2` + URL opening with automatic cookie handling. + + Module :mod:`Cookie` + HTTP cookie classes, principally useful for server-side code. The + :mod:`cookielib` and :mod:`Cookie` modules do not depend on each other. + + http://wwwsearch.sf.net/ClientCookie/ + Extensions to this module, including a class for reading Microsoft Internet + Explorer cookies on Windows. + + http://www.netscape.com/newsref/std/cookie_spec.html + The specification of the original Netscape cookie protocol. Though this is + still the dominant protocol, the 'Netscape cookie protocol' implemented by all + the major browsers (and :mod:`cookielib`) only bears a passing resemblance to + the one sketched out in ``cookie_spec.html``. + + :rfc:`2109` - HTTP State Management Mechanism + Obsoleted by RFC 2965. Uses :mailheader:`Set-Cookie` with version=1. + + :rfc:`2965` - HTTP State Management Mechanism + The Netscape protocol with the bugs fixed. Uses :mailheader:`Set-Cookie2` in + place of :mailheader:`Set-Cookie`. Not widely used. + + http://kristol.org/cookie/errata.html + Unfinished errata to RFC 2965. + + :rfc:`2964` - Use of HTTP State Management + +.. _cookie-jar-objects: + +CookieJar and FileCookieJar Objects +----------------------------------- + +:class:`CookieJar` objects support the iterator protocol for iterating over +contained :class:`Cookie` objects. + +:class:`CookieJar` has the following methods: + + +.. method:: CookieJar.add_cookie_header(request) + + Add correct :mailheader:`Cookie` header to *request*. + + If policy allows (ie. the :attr:`rfc2965` and :attr:`hide_cookie2` attributes of + the :class:`CookieJar`'s :class:`CookiePolicy` instance are true and false + respectively), the :mailheader:`Cookie2` header is also added when appropriate. + + The *request* object (usually a :class:`urllib2.Request` instance) must support + the methods :meth:`get_full_url`, :meth:`get_host`, :meth:`get_type`, + :meth:`unverifiable`, :meth:`get_origin_req_host`, :meth:`has_header`, + :meth:`get_header`, :meth:`header_items`, and :meth:`add_unredirected_header`,as + documented by :mod:`urllib2`. + + +.. method:: CookieJar.extract_cookies(response, request) + + Extract cookies from HTTP *response* and store them in the :class:`CookieJar`, + where allowed by policy. + + The :class:`CookieJar` will look for allowable :mailheader:`Set-Cookie` and + :mailheader:`Set-Cookie2` headers in the *response* argument, and store cookies + as appropriate (subject to the :meth:`CookiePolicy.set_ok` method's approval). + + The *response* object (usually the result of a call to :meth:`urllib2.urlopen`, + or similar) should support an :meth:`info` method, which returns an object with + a :meth:`getallmatchingheaders` method (usually a :class:`mimetools.Message` + instance). + + The *request* object (usually a :class:`urllib2.Request` instance) must support + the methods :meth:`get_full_url`, :meth:`get_host`, :meth:`unverifiable`, and + :meth:`get_origin_req_host`, as documented by :mod:`urllib2`. The request is + used to set default values for cookie-attributes as well as for checking that + the cookie is allowed to be set. + + +.. method:: CookieJar.set_policy(policy) + + Set the :class:`CookiePolicy` instance to be used. + + +.. method:: CookieJar.make_cookies(response, request) + + Return sequence of :class:`Cookie` objects extracted from *response* object. + + See the documentation for :meth:`extract_cookies` for the interfaces required of + the *response* and *request* arguments. + + +.. method:: CookieJar.set_cookie_if_ok(cookie, request) + + Set a :class:`Cookie` if policy says it's OK to do so. + + +.. method:: CookieJar.set_cookie(cookie) + + Set a :class:`Cookie`, without checking with policy to see whether or not it + should be set. + + +.. method:: CookieJar.clear([domain[, path[, name]]]) + + Clear some cookies. + + If invoked without arguments, clear all cookies. If given a single argument, + only cookies belonging to that *domain* will be removed. If given two arguments, + cookies belonging to the specified *domain* and URL *path* are removed. If + given three arguments, then the cookie with the specified *domain*, *path* and + *name* is removed. + + Raises :exc:`KeyError` if no matching cookie exists. + + +.. method:: CookieJar.clear_session_cookies() + + Discard all session cookies. + + Discards all contained cookies that have a true :attr:`discard` attribute + (usually because they had either no ``max-age`` or ``expires`` cookie-attribute, + or an explicit ``discard`` cookie-attribute). For interactive browsers, the end + of a session usually corresponds to closing the browser window. + + Note that the :meth:`save` method won't save session cookies anyway, unless you + ask otherwise by passing a true *ignore_discard* argument. + +:class:`FileCookieJar` implements the following additional methods: + + +.. method:: FileCookieJar.save(filename=None, ignore_discard=False, ignore_expires=False) + + Save cookies to a file. + + This base class raises :exc:`NotImplementedError`. Subclasses may leave this + method unimplemented. + + *filename* is the name of file in which to save cookies. If *filename* is not + specified, :attr:`self.filename` is used (whose default is the value passed to + the constructor, if any); if :attr:`self.filename` is :const:`None`, + :exc:`ValueError` is raised. + + *ignore_discard*: save even cookies set to be discarded. *ignore_expires*: save + even cookies that have expired + + The file is overwritten if it already exists, thus wiping all the cookies it + contains. Saved cookies can be restored later using the :meth:`load` or + :meth:`revert` methods. + + +.. method:: FileCookieJar.load(filename=None, ignore_discard=False, ignore_expires=False) + + Load cookies from a file. + + Old cookies are kept unless overwritten by newly loaded ones. + + Arguments are as for :meth:`save`. + + The named file must be in the format understood by the class, or + :exc:`LoadError` will be raised. Also, :exc:`IOError` may be raised, for + example if the file does not exist. + + .. note:: + + For backwards-compatibility with Python 2.4 (which raised an :exc:`IOError`), + :exc:`LoadError` is a subclass of :exc:`IOError`. + + +.. method:: FileCookieJar.revert(filename=None, ignore_discard=False, ignore_expires=False) + + Clear all cookies and reload cookies from a saved file. + + :meth:`revert` can raise the same exceptions as :meth:`load`. If there is a + failure, the object's state will not be altered. + +:class:`FileCookieJar` instances have the following public attributes: + + +.. attribute:: FileCookieJar.filename + + Filename of default file in which to keep cookies. This attribute may be + assigned to. + + +.. attribute:: FileCookieJar.delayload + + If true, load cookies lazily from disk. This attribute should not be assigned + to. This is only a hint, since this only affects performance, not behaviour + (unless the cookies on disk are changing). A :class:`CookieJar` object may + ignore it. None of the :class:`FileCookieJar` classes included in the standard + library lazily loads cookies. + + +.. _file-cookie-jar-classes: + +FileCookieJar subclasses and co-operation with web browsers +----------------------------------------------------------- + +The following :class:`CookieJar` subclasses are provided for reading and writing +. Further :class:`CookieJar` subclasses, including one that reads Microsoft +Internet Explorer cookies, are available at +http://wwwsearch.sf.net/ClientCookie/. + + +.. class:: MozillaCookieJar(filename, delayload=None, policy=None) + + A :class:`FileCookieJar` that can load from and save cookies to disk in the + Mozilla ``cookies.txt`` file format (which is also used by the Lynx and Netscape + browsers). + + .. note:: + + This loses information about RFC 2965 cookies, and also about newer or + non-standard cookie-attributes such as ``port``. + + .. warning:: + + Back up your cookies before saving if you have cookies whose loss / corruption + would be inconvenient (there are some subtleties which may lead to slight + changes in the file over a load / save round-trip). + + Also note that cookies saved while Mozilla is running will get clobbered by + Mozilla. + + +.. class:: LWPCookieJar(filename, delayload=None, policy=None) + + A :class:`FileCookieJar` that can load from and save cookies to disk in format + compatible with the libwww-perl library's ``Set-Cookie3`` file format. This is + convenient if you want to store cookies in a human-readable file. + + +.. _cookie-policy-objects: + +CookiePolicy Objects +-------------------- + +Objects implementing the :class:`CookiePolicy` interface have the following +methods: + + +.. method:: CookiePolicy.set_ok(cookie, request) + + Return boolean value indicating whether cookie should be accepted from server. + + *cookie* is a :class:`cookielib.Cookie` instance. *request* is an object + implementing the interface defined by the documentation for + :meth:`CookieJar.extract_cookies`. + + +.. method:: CookiePolicy.return_ok(cookie, request) + + Return boolean value indicating whether cookie should be returned to server. + + *cookie* is a :class:`cookielib.Cookie` instance. *request* is an object + implementing the interface defined by the documentation for + :meth:`CookieJar.add_cookie_header`. + + +.. method:: CookiePolicy.domain_return_ok(domain, request) + + Return false if cookies should not be returned, given cookie domain. + + This method is an optimization. It removes the need for checking every cookie + with a particular domain (which might involve reading many files). Returning + true from :meth:`domain_return_ok` and :meth:`path_return_ok` leaves all the + work to :meth:`return_ok`. + + If :meth:`domain_return_ok` returns true for the cookie domain, + :meth:`path_return_ok` is called for the cookie path. Otherwise, + :meth:`path_return_ok` and :meth:`return_ok` are never called for that cookie + domain. If :meth:`path_return_ok` returns true, :meth:`return_ok` is called + with the :class:`Cookie` object itself for a full check. Otherwise, + :meth:`return_ok` is never called for that cookie path. + + Note that :meth:`domain_return_ok` is called for every *cookie* domain, not just + for the *request* domain. For example, the function might be called with both + ``".example.com"`` and ``"www.example.com"`` if the request domain is + ``"www.example.com"``. The same goes for :meth:`path_return_ok`. + + The *request* argument is as documented for :meth:`return_ok`. + + +.. method:: CookiePolicy.path_return_ok(path, request) + + Return false if cookies should not be returned, given cookie path. + + See the documentation for :meth:`domain_return_ok`. + +In addition to implementing the methods above, implementations of the +:class:`CookiePolicy` interface must also supply the following attributes, +indicating which protocols should be used, and how. All of these attributes may +be assigned to. + + +.. attribute:: CookiePolicy.netscape + + Implement Netscape protocol. + + +.. attribute:: CookiePolicy.rfc2965 + + Implement RFC 2965 protocol. + + +.. attribute:: CookiePolicy.hide_cookie2 + + Don't add :mailheader:`Cookie2` header to requests (the presence of this header + indicates to the server that we understand RFC 2965 cookies). + +The most useful way to define a :class:`CookiePolicy` class is by subclassing +from :class:`DefaultCookiePolicy` and overriding some or all of the methods +above. :class:`CookiePolicy` itself may be used as a 'null policy' to allow +setting and receiving any and all cookies (this is unlikely to be useful). + + +.. _default-cookie-policy-objects: + +DefaultCookiePolicy Objects +--------------------------- + +Implements the standard rules for accepting and returning cookies. + +Both RFC 2965 and Netscape cookies are covered. RFC 2965 handling is switched +off by default. + +The easiest way to provide your own policy is to override this class and call +its methods in your overridden implementations before adding your own additional +checks:: + + import cookielib + class MyCookiePolicy(cookielib.DefaultCookiePolicy): + def set_ok(self, cookie, request): + if not cookielib.DefaultCookiePolicy.set_ok(self, cookie, request): + return False + if i_dont_want_to_store_this_cookie(cookie): + return False + return True + +In addition to the features required to implement the :class:`CookiePolicy` +interface, this class allows you to block and allow domains from setting and +receiving cookies. There are also some strictness switches that allow you to +tighten up the rather loose Netscape protocol rules a little bit (at the cost of +blocking some benign cookies). + +A domain blacklist and whitelist is provided (both off by default). Only domains +not in the blacklist and present in the whitelist (if the whitelist is active) +participate in cookie setting and returning. Use the *blocked_domains* +constructor argument, and :meth:`blocked_domains` and +:meth:`set_blocked_domains` methods (and the corresponding argument and methods +for *allowed_domains*). If you set a whitelist, you can turn it off again by +setting it to :const:`None`. + +Domains in block or allow lists that do not start with a dot must equal the +cookie domain to be matched. For example, ``"example.com"`` matches a blacklist +entry of ``"example.com"``, but ``"www.example.com"`` does not. Domains that do +start with a dot are matched by more specific domains too. For example, both +``"www.example.com"`` and ``"www.coyote.example.com"`` match ``".example.com"`` +(but ``"example.com"`` itself does not). IP addresses are an exception, and +must match exactly. For example, if blocked_domains contains ``"192.168.1.2"`` +and ``".168.1.2"``, 192.168.1.2 is blocked, but 193.168.1.2 is not. + +:class:`DefaultCookiePolicy` implements the following additional methods: + + +.. method:: DefaultCookiePolicy.blocked_domains() + + Return the sequence of blocked domains (as a tuple). + + +.. method:: DefaultCookiePolicy.set_blocked_domains(blocked_domains) + + Set the sequence of blocked domains. + + +.. method:: DefaultCookiePolicy.is_blocked(domain) + + Return whether *domain* is on the blacklist for setting or receiving cookies. + + +.. method:: DefaultCookiePolicy.allowed_domains() + + Return :const:`None`, or the sequence of allowed domains (as a tuple). + + +.. method:: DefaultCookiePolicy.set_allowed_domains(allowed_domains) + + Set the sequence of allowed domains, or :const:`None`. + + +.. method:: DefaultCookiePolicy.is_not_allowed(domain) + + Return whether *domain* is not on the whitelist for setting or receiving + cookies. + +:class:`DefaultCookiePolicy` instances have the following attributes, which are +all initialised from the constructor arguments of the same name, and which may +all be assigned to. + + +.. attribute:: DefaultCookiePolicy.rfc2109_as_netscape + + If true, request that the :class:`CookieJar` instance downgrade RFC 2109 cookies + (ie. cookies received in a :mailheader:`Set-Cookie` header with a version + cookie-attribute of 1) to Netscape cookies by setting the version attribute of + the :class:`Cookie` instance to 0. The default value is :const:`None`, in which + case RFC 2109 cookies are downgraded if and only if RFC 2965 handling is turned + off. Therefore, RFC 2109 cookies are downgraded by default. + + .. versionadded:: 2.5 + +General strictness switches: + + +.. attribute:: DefaultCookiePolicy.strict_domain + + Don't allow sites to set two-component domains with country-code top-level + domains like ``.co.uk``, ``.gov.uk``, ``.co.nz``.etc. This is far from perfect + and isn't guaranteed to work! + +RFC 2965 protocol strictness switches: + + +.. attribute:: DefaultCookiePolicy.strict_rfc2965_unverifiable + + Follow RFC 2965 rules on unverifiable transactions (usually, an unverifiable + transaction is one resulting from a redirect or a request for an image hosted on + another site). If this is false, cookies are *never* blocked on the basis of + verifiability + +Netscape protocol strictness switches: + + +.. attribute:: DefaultCookiePolicy.strict_ns_unverifiable + + apply RFC 2965 rules on unverifiable transactions even to Netscape cookies + + +.. attribute:: DefaultCookiePolicy.strict_ns_domain + + Flags indicating how strict to be with domain-matching rules for Netscape + cookies. See below for acceptable values. + + +.. attribute:: DefaultCookiePolicy.strict_ns_set_initial_dollar + + Ignore cookies in Set-Cookie: headers that have names starting with ``'$'``. + + +.. attribute:: DefaultCookiePolicy.strict_ns_set_path + + Don't allow setting cookies whose path doesn't path-match request URI. + +:attr:`strict_ns_domain` is a collection of flags. Its value is constructed by +or-ing together (for example, ``DomainStrictNoDots|DomainStrictNonDomain`` means +both flags are set). + + +.. attribute:: DefaultCookiePolicy.DomainStrictNoDots + + When setting cookies, the 'host prefix' must not contain a dot (eg. + ``www.foo.bar.com`` can't set a cookie for ``.bar.com``, because ``www.foo`` + contains a dot). + + +.. attribute:: DefaultCookiePolicy.DomainStrictNonDomain + + Cookies that did not explicitly specify a ``domain`` cookie-attribute can only + be returned to a domain equal to the domain that set the cookie (eg. + ``spam.example.com`` won't be returned cookies from ``example.com`` that had no + ``domain`` cookie-attribute). + + +.. attribute:: DefaultCookiePolicy.DomainRFC2965Match + + When setting cookies, require a full RFC 2965 domain-match. + +The following attributes are provided for convenience, and are the most useful +combinations of the above flags: + + +.. attribute:: DefaultCookiePolicy.DomainLiberal + + Equivalent to 0 (ie. all of the above Netscape domain strictness flags switched + off). + + +.. attribute:: DefaultCookiePolicy.DomainStrict + + Equivalent to ``DomainStrictNoDots|DomainStrictNonDomain``. + + +.. _cookielib-cookie-objects: + +Cookie Objects +-------------- + +:class:`Cookie` instances have Python attributes roughly corresponding to the +standard cookie-attributes specified in the various cookie standards. The +correspondence is not one-to-one, because there are complicated rules for +assigning default values, because the ``max-age`` and ``expires`` +cookie-attributes contain equivalent information, and because RFC 2109 cookies +may be 'downgraded' by :mod:`cookielib` from version 1 to version 0 (Netscape) +cookies. + +Assignment to these attributes should not be necessary other than in rare +circumstances in a :class:`CookiePolicy` method. The class does not enforce +internal consistency, so you should know what you're doing if you do that. + + +.. attribute:: Cookie.version + + Integer or :const:`None`. Netscape cookies have :attr:`version` 0. RFC 2965 and + RFC 2109 cookies have a ``version`` cookie-attribute of 1. However, note that + :mod:`cookielib` may 'downgrade' RFC 2109 cookies to Netscape cookies, in which + case :attr:`version` is 0. + + +.. attribute:: Cookie.name + + Cookie name (a string). + + +.. attribute:: Cookie.value + + Cookie value (a string), or :const:`None`. + + +.. attribute:: Cookie.port + + String representing a port or a set of ports (eg. '80', or '80,8080'), or + :const:`None`. + + +.. attribute:: Cookie.path + + Cookie path (a string, eg. ``'/acme/rocket_launchers'``). + + +.. attribute:: Cookie.secure + + True if cookie should only be returned over a secure connection. + + +.. attribute:: Cookie.expires + + Integer expiry date in seconds since epoch, or :const:`None`. See also the + :meth:`is_expired` method. + + +.. attribute:: Cookie.discard + + True if this is a session cookie. + + +.. attribute:: Cookie.comment + + String comment from the server explaining the function of this cookie, or + :const:`None`. + + +.. attribute:: Cookie.comment_url + + URL linking to a comment from the server explaining the function of this cookie, + or :const:`None`. + + +.. attribute:: Cookie.rfc2109 + + True if this cookie was received as an RFC 2109 cookie (ie. the cookie + arrived in a :mailheader:`Set-Cookie` header, and the value of the Version + cookie-attribute in that header was 1). This attribute is provided because + :mod:`cookielib` may 'downgrade' RFC 2109 cookies to Netscape cookies, in + which case :attr:`version` is 0. + + .. versionadded:: 2.5 + + +.. attribute:: Cookie.port_specified + + True if a port or set of ports was explicitly specified by the server (in the + :mailheader:`Set-Cookie` / :mailheader:`Set-Cookie2` header). + + +.. attribute:: Cookie.domain_specified + + True if a domain was explicitly specified by the server. + + +.. attribute:: Cookie.domain_initial_dot + + True if the domain explicitly specified by the server began with a dot + (``'.'``). + +Cookies may have additional non-standard cookie-attributes. These may be +accessed using the following methods: + + +.. method:: Cookie.has_nonstandard_attr(name) + + Return true if cookie has the named cookie-attribute. + + +.. method:: Cookie.get_nonstandard_attr(name, default=None) + + If cookie has the named cookie-attribute, return its value. Otherwise, return + *default*. + + +.. method:: Cookie.set_nonstandard_attr(name, value) + + Set the value of the named cookie-attribute. + +The :class:`Cookie` class also defines the following method: + + +.. method:: Cookie.is_expired([now=:const:`None`]) + + True if cookie has passed the time at which the server requested it should + expire. If *now* is given (in seconds since the epoch), return whether the + cookie has expired at the specified time. + + +.. _cookielib-examples: + +Examples +-------- + +The first example shows the most common usage of :mod:`cookielib`:: + + import cookielib, urllib2 + cj = cookielib.CookieJar() + opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj)) + r = opener.open("http://example.com/") + +This example illustrates how to open a URL using your Netscape, Mozilla, or Lynx +cookies (assumes Unix/Netscape convention for location of the cookies file):: + + import os, cookielib, urllib2 + cj = cookielib.MozillaCookieJar() + cj.load(os.path.join(os.environ["HOME"], ".netscape/cookies.txt")) + opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj)) + r = opener.open("http://example.com/") + +The next example illustrates the use of :class:`DefaultCookiePolicy`. Turn on +RFC 2965 cookies, be more strict about domains when setting and returning +Netscape cookies, and block some domains from setting cookies or having them +returned:: + + import urllib2 + from cookielib import CookieJar, DefaultCookiePolicy + policy = DefaultCookiePolicy( + rfc2965=True, strict_ns_domain=Policy.DomainStrict, + blocked_domains=["ads.net", ".ads.net"]) + cj = CookieJar(policy) + opener = urllib2.build_opener(urllib2.HTTPCookieProcessor(cj)) + r = opener.open("http://example.com/") + diff --git a/Doc/library/copy.rst b/Doc/library/copy.rst new file mode 100644 index 0000000..6fb3100 --- /dev/null +++ b/Doc/library/copy.rst @@ -0,0 +1,85 @@ + +:mod:`copy` --- Shallow and deep copy operations +================================================ + +.. module:: copy + :synopsis: Shallow and deep copy operations. + + +.. index:: + single: copy() (in copy) + single: deepcopy() (in copy) + +This module provides generic (shallow and deep) copying operations. + +Interface summary:: + + import copy + + x = copy.copy(y) # make a shallow copy of y + x = copy.deepcopy(y) # make a deep copy of y + +For module specific errors, :exc:`copy.error` is raised. + +.. % + +The difference between shallow and deep copying is only relevant for compound +objects (objects that contain other objects, like lists or class instances): + +* A *shallow copy* constructs a new compound object and then (to the extent + possible) inserts *references* into it to the objects found in the original. + +* A *deep copy* constructs a new compound object and then, recursively, inserts + *copies* into it of the objects found in the original. + +Two problems often exist with deep copy operations that don't exist with shallow +copy operations: + +* Recursive objects (compound objects that, directly or indirectly, contain a + reference to themselves) may cause a recursive loop. + +* Because deep copy copies *everything* it may copy too much, e.g., + administrative data structures that should be shared even between copies. + +The :func:`deepcopy` function avoids these problems by: + +* keeping a "memo" dictionary of objects already copied during the current + copying pass; and + +* letting user-defined classes override the copying operation or the set of + components copied. + +This module does not copy types like module, method, stack trace, stack frame, +file, socket, window, array, or any similar types. It does "copy" functions and +classes (shallow and deeply), by returning the original object unchanged; this +is compatible with the way these are treated by the :mod:`pickle` module. + +.. versionchanged:: 2.5 + Added copying functions. + +.. index:: module: pickle + +Classes can use the same interfaces to control copying that they use to control +pickling. See the description of module :mod:`pickle` for information on these +methods. The :mod:`copy` module does not use the :mod:`copy_reg` registration +module. + +.. index:: + single: __copy__() (copy protocol) + single: __deepcopy__() (copy protocol) + +In order for a class to define its own copy implementation, it can define +special methods :meth:`__copy__` and :meth:`__deepcopy__`. The former is called +to implement the shallow copy operation; no additional arguments are passed. +The latter is called to implement the deep copy operation; it is passed one +argument, the memo dictionary. If the :meth:`__deepcopy__` implementation needs +to make a deep copy of a component, it should call the :func:`deepcopy` function +with the component as first argument and the memo dictionary as second argument. + + +.. seealso:: + + Module :mod:`pickle` + Discussion of the special methods used to support object state retrieval and + restoration. + diff --git a/Doc/library/copy_reg.rst b/Doc/library/copy_reg.rst new file mode 100644 index 0000000..9b82a31 --- /dev/null +++ b/Doc/library/copy_reg.rst @@ -0,0 +1,42 @@ + +:mod:`copy_reg` --- Register :mod:`pickle` support functions +============================================================ + +.. module:: copy_reg + :synopsis: Register pickle support functions. + + +.. index:: + module: pickle + module: cPickle + module: copy + +The :mod:`copy_reg` module provides support for the :mod:`pickle` and +:mod:`cPickle` modules. The :mod:`copy` module is likely to use this in the +future as well. It provides configuration information about object constructors +which are not classes. Such constructors may be factory functions or class +instances. + + +.. function:: constructor(object) + + Declares *object* to be a valid constructor. If *object* is not callable (and + hence not valid as a constructor), raises :exc:`TypeError`. + + +.. function:: pickle(type, function[, constructor]) + + Declares that *function* should be used as a "reduction" function for objects of + type *type*; *type* must not be a "classic" class object. (Classic classes are + handled differently; see the documentation for the :mod:`pickle` module for + details.) *function* should return either a string or a tuple containing two or + three elements. + + The optional *constructor* parameter, if provided, is a callable object which + can be used to reconstruct the object when called with the tuple of arguments + returned by *function* at pickling time. :exc:`TypeError` will be raised if + *object* is a class or *constructor* is not callable. + + See the :mod:`pickle` module for more details on the interface expected of + *function* and *constructor*. + diff --git a/Doc/library/crypt.rst b/Doc/library/crypt.rst new file mode 100644 index 0000000..8840fc7 --- /dev/null +++ b/Doc/library/crypt.rst @@ -0,0 +1,66 @@ + +:mod:`crypt` --- Function to check Unix passwords +================================================= + +.. module:: crypt + :platform: Unix + :synopsis: The crypt() function used to check Unix passwords. +.. moduleauthor:: Steven D. Majewski +.. sectionauthor:: Steven D. Majewski +.. sectionauthor:: Peter Funk + + +.. index:: + single: crypt(3) + pair: cipher; DES + +This module implements an interface to the :manpage:`crypt(3)` routine, which is +a one-way hash function based upon a modified DES algorithm; see the Unix man +page for further details. Possible uses include allowing Python scripts to +accept typed passwords from the user, or attempting to crack Unix passwords with +a dictionary. + +.. index:: single: crypt(3) + +Notice that the behavior of this module depends on the actual implementation of +the :manpage:`crypt(3)` routine in the running system. Therefore, any +extensions available on the current implementation will also be available on +this module. + + +.. function:: crypt(word, salt) + + *word* will usually be a user's password as typed at a prompt or in a graphical + interface. *salt* is usually a random two-character string which will be used + to perturb the DES algorithm in one of 4096 ways. The characters in *salt* must + be in the set ``[./a-zA-Z0-9]``. Returns the hashed password as a string, which + will be composed of characters from the same alphabet as the salt (the first two + characters represent the salt itself). + + .. index:: single: crypt(3) + + Since a few :manpage:`crypt(3)` extensions allow different values, with + different sizes in the *salt*, it is recommended to use the full crypted + password as salt when checking for a password. + +A simple example illustrating typical use:: + + import crypt, getpass, pwd + + def raw_input(prompt): + import sys + sys.stdout.write(prompt) + sys.stdout.flush() + return sys.stdin.readline() + + def login(): + username = raw_input('Python login:') + cryptedpasswd = pwd.getpwnam(username)[1] + if cryptedpasswd: + if cryptedpasswd == 'x' or cryptedpasswd == '*': + raise "Sorry, currently no support for shadow passwords" + cleartext = getpass.getpass() + return crypt.crypt(cleartext, cryptedpasswd) == cryptedpasswd + else: + return 1 + diff --git a/Doc/library/crypto.rst b/Doc/library/crypto.rst new file mode 100644 index 0000000..dce5a01 --- /dev/null +++ b/Doc/library/crypto.rst @@ -0,0 +1,30 @@ + +.. _crypto: + +********************** +Cryptographic Services +********************** + +.. index:: single: cryptography + +The modules described in this chapter implement various algorithms of a +cryptographic nature. They are available at the discretion of the installation. +Here's an overview: + + +.. toctree:: + + hashlib.rst + hmac.rst + +.. index:: + pair: AES; algorithm + single: cryptography + single: Kuchling, Andrew + +Hardcore cypherpunks will probably find the cryptographic modules written by +A.M. Kuchling of further interest; the package contains modules for various +encryption algorithms, most notably AES. These modules are not distributed with +Python but available separately. See the URL +http://www.amk.ca/python/code/crypto.html for more information. + diff --git a/Doc/library/csv.rst b/Doc/library/csv.rst new file mode 100644 index 0000000..19123c6 --- /dev/null +++ b/Doc/library/csv.rst @@ -0,0 +1,530 @@ + +:mod:`csv` --- CSV File Reading and Writing +=========================================== + +.. module:: csv + :synopsis: Write and read tabular data to and from delimited files. +.. sectionauthor:: Skip Montanaro + + +.. versionadded:: 2.3 + +.. index:: + single: csv + pair: data; tabular + +The so-called CSV (Comma Separated Values) format is the most common import and +export format for spreadsheets and databases. There is no "CSV standard", so +the format is operationally defined by the many applications which read and +write it. The lack of a standard means that subtle differences often exist in +the data produced and consumed by different applications. These differences can +make it annoying to process CSV files from multiple sources. Still, while the +delimiters and quoting characters vary, the overall format is similar enough +that it is possible to write a single module which can efficiently manipulate +such data, hiding the details of reading and writing the data from the +programmer. + +The :mod:`csv` module implements classes to read and write tabular data in CSV +format. It allows programmers to say, "write this data in the format preferred +by Excel," or "read data from this file which was generated by Excel," without +knowing the precise details of the CSV format used by Excel. Programmers can +also describe the CSV formats understood by other applications or define their +own special-purpose CSV formats. + +The :mod:`csv` module's :class:`reader` and :class:`writer` objects read and +write sequences. Programmers can also read and write data in dictionary form +using the :class:`DictReader` and :class:`DictWriter` classes. + +.. note:: + + This version of the :mod:`csv` module doesn't support Unicode input. Also, + there are currently some issues regarding ASCII NUL characters. Accordingly, + all input should be UTF-8 or printable ASCII to be safe; see the examples in + section :ref:`csv-examples`. These restrictions will be removed in the future. + + +.. seealso:: + + .. % \seemodule{array}{Arrays of uniformly types numeric values.} + + :pep:`305` - CSV File API + The Python Enhancement Proposal which proposed this addition to Python. + + +.. _csv-contents: + +Module Contents +--------------- + +The :mod:`csv` module defines the following functions: + + +.. function:: reader(csvfile[, dialect='excel'][, fmtparam]) + + Return a reader object which will iterate over lines in the given *csvfile*. + *csvfile* can be any object which supports the iterator protocol and returns a + string each time its :meth:`next` method is called --- file objects and list + objects are both suitable. If *csvfile* is a file object, it must be opened + with the 'b' flag on platforms where that makes a difference. An optional + *dialect* parameter can be given which is used to define a set of parameters + specific to a particular CSV dialect. It may be an instance of a subclass of + the :class:`Dialect` class or one of the strings returned by the + :func:`list_dialects` function. The other optional *fmtparam* keyword arguments + can be given to override individual formatting parameters in the current + dialect. For full details about the dialect and formatting parameters, see + section :ref:`csv-fmt-params`. + + All data read are returned as strings. No automatic data type conversion is + performed. + + .. versionchanged:: 2.5 + The parser is now stricter with respect to multi-line quoted fields. Previously, + if a line ended within a quoted field without a terminating newline character, a + newline would be inserted into the returned field. This behavior caused problems + when reading files which contained carriage return characters within fields. + The behavior was changed to return the field without inserting newlines. As a + consequence, if newlines embedded within fields are important, the input should + be split into lines in a manner which preserves the newline characters. + + +.. function:: writer(csvfile[, dialect='excel'][, fmtparam]) + + Return a writer object responsible for converting the user's data into delimited + strings on the given file-like object. *csvfile* can be any object with a + :func:`write` method. If *csvfile* is a file object, it must be opened with the + 'b' flag on platforms where that makes a difference. An optional *dialect* + parameter can be given which is used to define a set of parameters specific to a + particular CSV dialect. It may be an instance of a subclass of the + :class:`Dialect` class or one of the strings returned by the + :func:`list_dialects` function. The other optional *fmtparam* keyword arguments + can be given to override individual formatting parameters in the current + dialect. For full details about the dialect and formatting parameters, see + section :ref:`csv-fmt-params`. To make it + as easy as possible to interface with modules which implement the DB API, the + value :const:`None` is written as the empty string. While this isn't a + reversible transformation, it makes it easier to dump SQL NULL data values to + CSV files without preprocessing the data returned from a ``cursor.fetch*`` call. + All other non-string data are stringified with :func:`str` before being written. + + +.. function:: register_dialect(name[, dialect][, fmtparam]) + + Associate *dialect* with *name*. *name* must be a string or Unicode object. The + dialect can be specified either by passing a sub-class of :class:`Dialect`, or + by *fmtparam* keyword arguments, or both, with keyword arguments overriding + parameters of the dialect. For full details about the dialect and formatting + parameters, see section :ref:`csv-fmt-params`. + + +.. function:: unregister_dialect(name) + + Delete the dialect associated with *name* from the dialect registry. An + :exc:`Error` is raised if *name* is not a registered dialect name. + + +.. function:: get_dialect(name) + + Return the dialect associated with *name*. An :exc:`Error` is raised if *name* + is not a registered dialect name. + + +.. function:: list_dialects() + + Return the names of all registered dialects. + + +.. function:: field_size_limit([new_limit]) + + Returns the current maximum field size allowed by the parser. If *new_limit* is + given, this becomes the new limit. + + .. versionadded:: 2.5 + +The :mod:`csv` module defines the following classes: + + +.. class:: DictReader(csvfile[, fieldnames=:const:None,[, restkey=:const:None[, restval=None[, dialect='excel'[, *args, **kwds]]]]]) + + Create an object which operates like a regular reader but maps the information + read into a dict whose keys are given by the optional *fieldnames* parameter. + If the *fieldnames* parameter is omitted, the values in the first row of the + *csvfile* will be used as the fieldnames. If the row read has fewer fields than + the fieldnames sequence, the value of *restval* will be used as the default + value. If the row read has more fields than the fieldnames sequence, the + remaining data is added as a sequence keyed by the value of *restkey*. If the + row read has fewer fields than the fieldnames sequence, the remaining keys take + the value of the optional *restval* parameter. Any other optional or keyword + arguments are passed to the underlying :class:`reader` instance. + + +.. class:: DictWriter(csvfile, fieldnames[, restval=''[, extrasaction='raise'[, dialect='excel'[, *args, **kwds]]]]) + + Create an object which operates like a regular writer but maps dictionaries onto + output rows. The *fieldnames* parameter identifies the order in which values in + the dictionary passed to the :meth:`writerow` method are written to the + *csvfile*. The optional *restval* parameter specifies the value to be written + if the dictionary is missing a key in *fieldnames*. If the dictionary passed to + the :meth:`writerow` method contains a key not found in *fieldnames*, the + optional *extrasaction* parameter indicates what action to take. If it is set + to ``'raise'`` a :exc:`ValueError` is raised. If it is set to ``'ignore'``, + extra values in the dictionary are ignored. Any other optional or keyword + arguments are passed to the underlying :class:`writer` instance. + + Note that unlike the :class:`DictReader` class, the *fieldnames* parameter of + the :class:`DictWriter` is not optional. Since Python's :class:`dict` objects + are not ordered, there is not enough information available to deduce the order + in which the row should be written to the *csvfile*. + + +.. class:: Dialect + + The :class:`Dialect` class is a container class relied on primarily for its + attributes, which are used to define the parameters for a specific + :class:`reader` or :class:`writer` instance. + + +.. class:: excel() + + The :class:`excel` class defines the usual properties of an Excel-generated CSV + file. It is registered with the dialect name ``'excel'``. + + +.. class:: excel_tab() + + The :class:`excel_tab` class defines the usual properties of an Excel-generated + TAB-delimited file. It is registered with the dialect name ``'excel-tab'``. + + +.. class:: Sniffer() + + The :class:`Sniffer` class is used to deduce the format of a CSV file. + +The :class:`Sniffer` class provides two methods: + + +.. method:: Sniffer.sniff(sample[, delimiters=None]) + + Analyze the given *sample* and return a :class:`Dialect` subclass reflecting the + parameters found. If the optional *delimiters* parameter is given, it is + interpreted as a string containing possible valid delimiter characters. + + +.. method:: Sniffer.has_header(sample) + + Analyze the sample text (presumed to be in CSV format) and return :const:`True` + if the first row appears to be a series of column headers. + +The :mod:`csv` module defines the following constants: + + +.. data:: QUOTE_ALL + + Instructs :class:`writer` objects to quote all fields. + + +.. data:: QUOTE_MINIMAL + + Instructs :class:`writer` objects to only quote those fields which contain + special characters such as *delimiter*, *quotechar* or any of the characters in + *lineterminator*. + + +.. data:: QUOTE_NONNUMERIC + + Instructs :class:`writer` objects to quote all non-numeric fields. + + Instructs the reader to convert all non-quoted fields to type *float*. + + +.. data:: QUOTE_NONE + + Instructs :class:`writer` objects to never quote fields. When the current + *delimiter* occurs in output data it is preceded by the current *escapechar* + character. If *escapechar* is not set, the writer will raise :exc:`Error` if + any characters that require escaping are encountered. + + Instructs :class:`reader` to perform no special processing of quote characters. + +The :mod:`csv` module defines the following exception: + + +.. exception:: Error + + Raised by any of the functions when an error is detected. + + +.. _csv-fmt-params: + +Dialects and Formatting Parameters +---------------------------------- + +To make it easier to specify the format of input and output records, specific +formatting parameters are grouped together into dialects. A dialect is a +subclass of the :class:`Dialect` class having a set of specific methods and a +single :meth:`validate` method. When creating :class:`reader` or +:class:`writer` objects, the programmer can specify a string or a subclass of +the :class:`Dialect` class as the dialect parameter. In addition to, or instead +of, the *dialect* parameter, the programmer can also specify individual +formatting parameters, which have the same names as the attributes defined below +for the :class:`Dialect` class. + +Dialects support the following attributes: + + +.. attribute:: Dialect.delimiter + + A one-character string used to separate fields. It defaults to ``','``. + + +.. attribute:: Dialect.doublequote + + Controls how instances of *quotechar* appearing inside a field should be + themselves be quoted. When :const:`True`, the character is doubled. When + :const:`False`, the *escapechar* is used as a prefix to the *quotechar*. It + defaults to :const:`True`. + + On output, if *doublequote* is :const:`False` and no *escapechar* is set, + :exc:`Error` is raised if a *quotechar* is found in a field. + + +.. attribute:: Dialect.escapechar + + A one-character string used by the writer to escape the *delimiter* if *quoting* + is set to :const:`QUOTE_NONE` and the *quotechar* if *doublequote* is + :const:`False`. On reading, the *escapechar* removes any special meaning from + the following character. It defaults to :const:`None`, which disables escaping. + + +.. attribute:: Dialect.lineterminator + + The string used to terminate lines produced by the :class:`writer`. It defaults + to ``'\r\n'``. + + .. note:: + + The :class:`reader` is hard-coded to recognise either ``'\r'`` or ``'\n'`` as + end-of-line, and ignores *lineterminator*. This behavior may change in the + future. + + +.. attribute:: Dialect.quotechar + + A one-character string used to quote fields containing special characters, such + as the *delimiter* or *quotechar*, or which contain new-line characters. It + defaults to ``'"'``. + + +.. attribute:: Dialect.quoting + + Controls when quotes should be generated by the writer and recognised by the + reader. It can take on any of the :const:`QUOTE_\*` constants (see section + :ref:`csv-contents`) and defaults to :const:`QUOTE_MINIMAL`. + + +.. attribute:: Dialect.skipinitialspace + + When :const:`True`, whitespace immediately following the *delimiter* is ignored. + The default is :const:`False`. + + +Reader Objects +-------------- + +Reader objects (:class:`DictReader` instances and objects returned by the +:func:`reader` function) have the following public methods: + + +.. method:: csvreader.next() + + Return the next row of the reader's iterable object as a list, parsed according + to the current dialect. + +Reader objects have the following public attributes: + + +.. attribute:: csvreader.dialect + + A read-only description of the dialect in use by the parser. + + +.. attribute:: csvreader.line_num + + The number of lines read from the source iterator. This is not the same as the + number of records returned, as records can span multiple lines. + + .. versionadded:: 2.5 + + +Writer Objects +-------------- + +:class:`Writer` objects (:class:`DictWriter` instances and objects returned by +the :func:`writer` function) have the following public methods. A *row* must be +a sequence of strings or numbers for :class:`Writer` objects and a dictionary +mapping fieldnames to strings or numbers (by passing them through :func:`str` +first) for :class:`DictWriter` objects. Note that complex numbers are written +out surrounded by parens. This may cause some problems for other programs which +read CSV files (assuming they support complex numbers at all). + + +.. method:: csvwriter.writerow(row) + + Write the *row* parameter to the writer's file object, formatted according to + the current dialect. + + +.. method:: csvwriter.writerows(rows) + + Write all the *rows* parameters (a list of *row* objects as described above) to + the writer's file object, formatted according to the current dialect. + +Writer objects have the following public attribute: + + +.. attribute:: csvwriter.dialect + + A read-only description of the dialect in use by the writer. + + +.. _csv-examples: + +Examples +-------- + +The simplest example of reading a CSV file:: + + import csv + reader = csv.reader(open("some.csv", "rb")) + for row in reader: + print row + +Reading a file with an alternate format:: + + import csv + reader = csv.reader(open("passwd", "rb"), delimiter=':', quoting=csv.QUOTE_NONE) + for row in reader: + print row + +The corresponding simplest possible writing example is:: + + import csv + writer = csv.writer(open("some.csv", "wb")) + writer.writerows(someiterable) + +Registering a new dialect:: + + import csv + + csv.register_dialect('unixpwd', delimiter=':', quoting=csv.QUOTE_NONE) + + reader = csv.reader(open("passwd", "rb"), 'unixpwd') + +A slightly more advanced use of the reader --- catching and reporting errors:: + + import csv, sys + filename = "some.csv" + reader = csv.reader(open(filename, "rb")) + try: + for row in reader: + print row + except csv.Error as e: + sys.exit('file %s, line %d: %s' % (filename, reader.line_num, e)) + +And while the module doesn't directly support parsing strings, it can easily be +done:: + + import csv + for row in csv.reader(['one,two,three']): + print row + +The :mod:`csv` module doesn't directly support reading and writing Unicode, but +it is 8-bit-clean save for some problems with ASCII NUL characters. So you can +write functions or classes that handle the encoding and decoding for you as long +as you avoid encodings like UTF-16 that use NULs. UTF-8 is recommended. + +:func:`unicode_csv_reader` below is a generator that wraps :class:`csv.reader` +to handle Unicode CSV data (a list of Unicode strings). :func:`utf_8_encoder` +is a generator that encodes the Unicode strings as UTF-8, one string (or row) at +a time. The encoded strings are parsed by the CSV reader, and +:func:`unicode_csv_reader` decodes the UTF-8-encoded cells back into Unicode:: + + import csv + + def unicode_csv_reader(unicode_csv_data, dialect=csv.excel, **kwargs): + # csv.py doesn't do Unicode; encode temporarily as UTF-8: + csv_reader = csv.reader(utf_8_encoder(unicode_csv_data), + dialect=dialect, **kwargs) + for row in csv_reader: + # decode UTF-8 back to Unicode, cell by cell: + yield [unicode(cell, 'utf-8') for cell in row] + + def utf_8_encoder(unicode_csv_data): + for line in unicode_csv_data: + yield line.encode('utf-8') + +For all other encodings the following :class:`UnicodeReader` and +:class:`UnicodeWriter` classes can be used. They take an additional *encoding* +parameter in their constructor and make sure that the data passes the real +reader or writer encoded as UTF-8:: + + import csv, codecs, cStringIO + + class UTF8Recoder: + """ + Iterator that reads an encoded stream and reencodes the input to UTF-8 + """ + def __init__(self, f, encoding): + self.reader = codecs.getreader(encoding)(f) + + def __iter__(self): + return self + + def __next__(self): + return next(self.reader).encode("utf-8") + + class UnicodeReader: + """ + A CSV reader which will iterate over lines in the CSV file "f", + which is encoded in the given encoding. + """ + + def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds): + f = UTF8Recoder(f, encoding) + self.reader = csv.reader(f, dialect=dialect, **kwds) + + def __next__(self): + row = next(self.reader) + return [unicode(s, "utf-8") for s in row] + + def __iter__(self): + return self + + class UnicodeWriter: + """ + A CSV writer which will write rows to CSV file "f", + which is encoded in the given encoding. + """ + + def __init__(self, f, dialect=csv.excel, encoding="utf-8", **kwds): + # Redirect output to a queue + self.queue = cStringIO.StringIO() + self.writer = csv.writer(self.queue, dialect=dialect, **kwds) + self.stream = f + self.encoder = codecs.getincrementalencoder(encoding)() + + def writerow(self, row): + self.writer.writerow([s.encode("utf-8") for s in row]) + # Fetch UTF-8 output from the queue ... + data = self.queue.getvalue() + data = data.decode("utf-8") + # ... and reencode it into the target encoding + data = self.encoder.encode(data) + # write to the target stream + self.stream.write(data) + # empty queue + self.queue.truncate(0) + + def writerows(self, rows): + for row in rows: + self.writerow(row) + diff --git a/Doc/library/ctypes.rst b/Doc/library/ctypes.rst new file mode 100644 index 0000000..dc37565 --- /dev/null +++ b/Doc/library/ctypes.rst @@ -0,0 +1,2364 @@ + +:mod:`ctypes` --- A foreign function library for Python. +======================================================== + +.. module:: ctypes + :synopsis: A foreign function library for Python. +.. moduleauthor:: Thomas Heller + + +.. versionadded:: 2.5 + +``ctypes`` is a foreign function library for Python. It provides C compatible +data types, and allows calling functions in dlls/shared libraries. It can be +used to wrap these libraries in pure Python. + + +.. _ctypes-ctypes-tutorial: + +ctypes tutorial +--------------- + +Note: The code samples in this tutorial use ``doctest`` to make sure that they +actually work. Since some code samples behave differently under Linux, Windows, +or Mac OS X, they contain doctest directives in comments. + +Note: Some code sample references the ctypes :class:`c_int` type. This type is +an alias to the :class:`c_long` type on 32-bit systems. So, you should not be +confused if :class:`c_long` is printed if you would expect :class:`c_int` --- +they are actually the same type. + + +.. _ctypes-loading-dynamic-link-libraries: + +Loading dynamic link libraries +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +``ctypes`` exports the *cdll*, and on Windows also *windll* and *oledll* objects +to load dynamic link libraries. + +You load libraries by accessing them as attributes of these objects. *cdll* +loads libraries which export functions using the standard ``cdecl`` calling +convention, while *windll* libraries call functions using the ``stdcall`` +calling convention. *oledll* also uses the ``stdcall`` calling convention, and +assumes the functions return a Windows :class:`HRESULT` error code. The error +code is used to automatically raise :class:`WindowsError` Python exceptions when +the function call fails. + +Here are some examples for Windows. Note that ``msvcrt`` is the MS standard C +library containing most standard C functions, and uses the cdecl calling +convention:: + + >>> from ctypes import * + >>> print windll.kernel32 # doctest: +WINDOWS + + >>> print cdll.msvcrt # doctest: +WINDOWS + + >>> libc = cdll.msvcrt # doctest: +WINDOWS + >>> + +Windows appends the usual '.dll' file suffix automatically. + +On Linux, it is required to specify the filename *including* the extension to +load a library, so attribute access does not work. Either the +:meth:`LoadLibrary` method of the dll loaders should be used, or you should load +the library by creating an instance of CDLL by calling the constructor:: + + >>> cdll.LoadLibrary("libc.so.6") # doctest: +LINUX + + >>> libc = CDLL("libc.so.6") # doctest: +LINUX + >>> libc # doctest: +LINUX + + >>> + +.. % XXX Add section for Mac OS X. + + +.. _ctypes-accessing-functions-from-loaded-dlls: + +Accessing functions from loaded dlls +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Functions are accessed as attributes of dll objects:: + + >>> from ctypes import * + >>> libc.printf + <_FuncPtr object at 0x...> + >>> print windll.kernel32.GetModuleHandleA # doctest: +WINDOWS + <_FuncPtr object at 0x...> + >>> print windll.kernel32.MyOwnFunction # doctest: +WINDOWS + Traceback (most recent call last): + File "", line 1, in ? + File "ctypes.py", line 239, in __getattr__ + func = _StdcallFuncPtr(name, self) + AttributeError: function 'MyOwnFunction' not found + >>> + +Note that win32 system dlls like ``kernel32`` and ``user32`` often export ANSI +as well as UNICODE versions of a function. The UNICODE version is exported with +an ``W`` appended to the name, while the ANSI version is exported with an ``A`` +appended to the name. The win32 ``GetModuleHandle`` function, which returns a +*module handle* for a given module name, has the following C prototype, and a +macro is used to expose one of them as ``GetModuleHandle`` depending on whether +UNICODE is defined or not:: + + /* ANSI version */ + HMODULE GetModuleHandleA(LPCSTR lpModuleName); + /* UNICODE version */ + HMODULE GetModuleHandleW(LPCWSTR lpModuleName); + +*windll* does not try to select one of them by magic, you must access the +version you need by specifying ``GetModuleHandleA`` or ``GetModuleHandleW`` +explicitely, and then call it with normal strings or unicode strings +respectively. + +Sometimes, dlls export functions with names which aren't valid Python +identifiers, like ``"??2@YAPAXI@Z"``. In this case you have to use ``getattr`` +to retrieve the function:: + + >>> getattr(cdll.msvcrt, "??2@YAPAXI@Z") # doctest: +WINDOWS + <_FuncPtr object at 0x...> + >>> + +On Windows, some dlls export functions not by name but by ordinal. These +functions can be accessed by indexing the dll object with the ordinal number:: + + >>> cdll.kernel32[1] # doctest: +WINDOWS + <_FuncPtr object at 0x...> + >>> cdll.kernel32[0] # doctest: +WINDOWS + Traceback (most recent call last): + File "", line 1, in ? + File "ctypes.py", line 310, in __getitem__ + func = _StdcallFuncPtr(name, self) + AttributeError: function ordinal 0 not found + >>> + + +.. _ctypes-calling-functions: + +Calling functions +^^^^^^^^^^^^^^^^^ + +You can call these functions like any other Python callable. This example uses +the ``time()`` function, which returns system time in seconds since the Unix +epoch, and the ``GetModuleHandleA()`` function, which returns a win32 module +handle. + +This example calls both functions with a NULL pointer (``None`` should be used +as the NULL pointer):: + + >>> print libc.time(None) # doctest: +SKIP + 1150640792 + >>> print hex(windll.kernel32.GetModuleHandleA(None)) # doctest: +WINDOWS + 0x1d000000 + >>> + +``ctypes`` tries to protect you from calling functions with the wrong number of +arguments or the wrong calling convention. Unfortunately this only works on +Windows. It does this by examining the stack after the function returns, so +although an error is raised the function *has* been called:: + + >>> windll.kernel32.GetModuleHandleA() # doctest: +WINDOWS + Traceback (most recent call last): + File "", line 1, in ? + ValueError: Procedure probably called with not enough arguments (4 bytes missing) + >>> windll.kernel32.GetModuleHandleA(0, 0) # doctest: +WINDOWS + Traceback (most recent call last): + File "", line 1, in ? + ValueError: Procedure probably called with too many arguments (4 bytes in excess) + >>> + +The same exception is raised when you call an ``stdcall`` function with the +``cdecl`` calling convention, or vice versa:: + + >>> cdll.kernel32.GetModuleHandleA(None) # doctest: +WINDOWS + Traceback (most recent call last): + File "", line 1, in ? + ValueError: Procedure probably called with not enough arguments (4 bytes missing) + >>> + + >>> windll.msvcrt.printf("spam") # doctest: +WINDOWS + Traceback (most recent call last): + File "", line 1, in ? + ValueError: Procedure probably called with too many arguments (4 bytes in excess) + >>> + +To find out the correct calling convention you have to look into the C header +file or the documentation for the function you want to call. + +On Windows, ``ctypes`` uses win32 structured exception handling to prevent +crashes from general protection faults when functions are called with invalid +argument values:: + + >>> windll.kernel32.GetModuleHandleA(32) # doctest: +WINDOWS + Traceback (most recent call last): + File "", line 1, in ? + WindowsError: exception: access violation reading 0x00000020 + >>> + +There are, however, enough ways to crash Python with ``ctypes``, so you should +be careful anyway. + +``None``, integers, longs, byte strings and unicode strings are the only native +Python objects that can directly be used as parameters in these function calls. +``None`` is passed as a C ``NULL`` pointer, byte strings and unicode strings are +passed as pointer to the memory block that contains their data (``char *`` or +``wchar_t *``). Python integers and Python longs are passed as the platforms +default C ``int`` type, their value is masked to fit into the C type. + +Before we move on calling functions with other parameter types, we have to learn +more about ``ctypes`` data types. + + +.. _ctypes-fundamental-data-types: + +Fundamental data types +^^^^^^^^^^^^^^^^^^^^^^ + +``ctypes`` defines a number of primitive C compatible data types : + + +----------------------+--------------------------------+----------------------------+ + | ctypes type | C type | Python type | + +======================+================================+============================+ + | :class:`c_char` | ``char`` | 1-character string | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_wchar` | ``wchar_t`` | 1-character unicode string | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_byte` | ``char`` | int/long | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_ubyte` | ``unsigned char`` | int/long | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_short` | ``short`` | int/long | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_ushort` | ``unsigned short`` | int/long | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_int` | ``int`` | int/long | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_uint` | ``unsigned int`` | int/long | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_long` | ``long`` | int/long | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_ulong` | ``unsigned long`` | int/long | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_longlong` | ``__int64`` or ``long long`` | int/long | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_ulonglong` | ``unsigned __int64`` or | int/long | + | | ``unsigned long long`` | | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_float` | ``float`` | float | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_double` | ``double`` | float | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_char_p` | ``char *`` (NUL terminated) | string or ``None`` | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_wchar_p` | ``wchar_t *`` (NUL terminated) | unicode or ``None`` | + +----------------------+--------------------------------+----------------------------+ + | :class:`c_void_p` | ``void *`` | int/long or ``None`` | + +----------------------+--------------------------------+----------------------------+ + + +All these types can be created by calling them with an optional initializer of +the correct type and value:: + + >>> c_int() + c_long(0) + >>> c_char_p("Hello, World") + c_char_p('Hello, World') + >>> c_ushort(-3) + c_ushort(65533) + >>> + +Since these types are mutable, their value can also be changed afterwards:: + + >>> i = c_int(42) + >>> print i + c_long(42) + >>> print i.value + 42 + >>> i.value = -99 + >>> print i.value + -99 + >>> + +Assigning a new value to instances of the pointer types :class:`c_char_p`, +:class:`c_wchar_p`, and :class:`c_void_p` changes the *memory location* they +point to, *not the contents* of the memory block (of course not, because Python +strings are immutable):: + + >>> s = "Hello, World" + >>> c_s = c_char_p(s) + >>> print c_s + c_char_p('Hello, World') + >>> c_s.value = "Hi, there" + >>> print c_s + c_char_p('Hi, there') + >>> print s # first string is unchanged + Hello, World + >>> + +You should be careful, however, not to pass them to functions expecting pointers +to mutable memory. If you need mutable memory blocks, ctypes has a +``create_string_buffer`` function which creates these in various ways. The +current memory block contents can be accessed (or changed) with the ``raw`` +property; if you want to access it as NUL terminated string, use the ``value`` +property:: + + >>> from ctypes import * + >>> p = create_string_buffer(3) # create a 3 byte buffer, initialized to NUL bytes + >>> print sizeof(p), repr(p.raw) + 3 '\x00\x00\x00' + >>> p = create_string_buffer("Hello") # create a buffer containing a NUL terminated string + >>> print sizeof(p), repr(p.raw) + 6 'Hello\x00' + >>> print repr(p.value) + 'Hello' + >>> p = create_string_buffer("Hello", 10) # create a 10 byte buffer + >>> print sizeof(p), repr(p.raw) + 10 'Hello\x00\x00\x00\x00\x00' + >>> p.value = "Hi" + >>> print sizeof(p), repr(p.raw) + 10 'Hi\x00lo\x00\x00\x00\x00\x00' + >>> + +The ``create_string_buffer`` function replaces the ``c_buffer`` function (which +is still available as an alias), as well as the ``c_string`` function from +earlier ctypes releases. To create a mutable memory block containing unicode +characters of the C type ``wchar_t`` use the ``create_unicode_buffer`` function. + + +.. _ctypes-calling-functions-continued: + +Calling functions, continued +^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Note that printf prints to the real standard output channel, *not* to +``sys.stdout``, so these examples will only work at the console prompt, not from +within *IDLE* or *PythonWin*:: + + >>> printf = libc.printf + >>> printf("Hello, %s\n", "World!") + Hello, World! + 14 + >>> printf("Hello, %S", u"World!") + Hello, World! + 13 + >>> printf("%d bottles of beer\n", 42) + 42 bottles of beer + 19 + >>> printf("%f bottles of beer\n", 42.5) + Traceback (most recent call last): + File "", line 1, in ? + ArgumentError: argument 2: exceptions.TypeError: Don't know how to convert parameter 2 + >>> + +As has been mentioned before, all Python types except integers, strings, and +unicode strings have to be wrapped in their corresponding ``ctypes`` type, so +that they can be converted to the required C data type:: + + >>> printf("An int %d, a double %f\n", 1234, c_double(3.14)) + Integer 1234, double 3.1400001049 + 31 + >>> + + +.. _ctypes-calling-functions-with-own-custom-data-types: + +Calling functions with your own custom data types +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +You can also customize ``ctypes`` argument conversion to allow instances of your +own classes be used as function arguments. ``ctypes`` looks for an +:attr:`_as_parameter_` attribute and uses this as the function argument. Of +course, it must be one of integer, string, or unicode:: + + >>> class Bottles(object): + ... def __init__(self, number): + ... self._as_parameter_ = number + ... + >>> bottles = Bottles(42) + >>> printf("%d bottles of beer\n", bottles) + 42 bottles of beer + 19 + >>> + +If you don't want to store the instance's data in the :attr:`_as_parameter_` +instance variable, you could define a ``property`` which makes the data +avaiblable. + + +.. _ctypes-specifying-required-argument-types: + +Specifying the required argument types (function prototypes) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +It is possible to specify the required argument types of functions exported from +DLLs by setting the :attr:`argtypes` attribute. + +:attr:`argtypes` must be a sequence of C data types (the ``printf`` function is +probably not a good example here, because it takes a variable number and +different types of parameters depending on the format string, on the other hand +this is quite handy to experiment with this feature):: + + >>> printf.argtypes = [c_char_p, c_char_p, c_int, c_double] + >>> printf("String '%s', Int %d, Double %f\n", "Hi", 10, 2.2) + String 'Hi', Int 10, Double 2.200000 + 37 + >>> + +Specifying a format protects against incompatible argument types (just as a +prototype for a C function), and tries to convert the arguments to valid types:: + + >>> printf("%d %d %d", 1, 2, 3) + Traceback (most recent call last): + File "", line 1, in ? + ArgumentError: argument 2: exceptions.TypeError: wrong type + >>> printf("%s %d %f", "X", 2, 3) + X 2 3.00000012 + 12 + >>> + +If you have defined your own classes which you pass to function calls, you have +to implement a :meth:`from_param` class method for them to be able to use them +in the :attr:`argtypes` sequence. The :meth:`from_param` class method receives +the Python object passed to the function call, it should do a typecheck or +whatever is needed to make sure this object is acceptable, and then return the +object itself, it's :attr:`_as_parameter_` attribute, or whatever you want to +pass as the C function argument in this case. Again, the result should be an +integer, string, unicode, a ``ctypes`` instance, or something having the +:attr:`_as_parameter_` attribute. + + +.. _ctypes-return-types: + +Return types +^^^^^^^^^^^^ + +By default functions are assumed to return the C ``int`` type. Other return +types can be specified by setting the :attr:`restype` attribute of the function +object. + +Here is a more advanced example, it uses the ``strchr`` function, which expects +a string pointer and a char, and returns a pointer to a string:: + + >>> strchr = libc.strchr + >>> strchr("abcdef", ord("d")) # doctest: +SKIP + 8059983 + >>> strchr.restype = c_char_p # c_char_p is a pointer to a string + >>> strchr("abcdef", ord("d")) + 'def' + >>> print strchr("abcdef", ord("x")) + None + >>> + +If you want to avoid the ``ord("x")`` calls above, you can set the +:attr:`argtypes` attribute, and the second argument will be converted from a +single character Python string into a C char:: + + >>> strchr.restype = c_char_p + >>> strchr.argtypes = [c_char_p, c_char] + >>> strchr("abcdef", "d") + 'def' + >>> strchr("abcdef", "def") + Traceback (most recent call last): + File "", line 1, in ? + ArgumentError: argument 2: exceptions.TypeError: one character string expected + >>> print strchr("abcdef", "x") + None + >>> strchr("abcdef", "d") + 'def' + >>> + +You can also use a callable Python object (a function or a class for example) as +the :attr:`restype` attribute, if the foreign function returns an integer. The +callable will be called with the ``integer`` the C function returns, and the +result of this call will be used as the result of your function call. This is +useful to check for error return values and automatically raise an exception:: + + >>> GetModuleHandle = windll.kernel32.GetModuleHandleA # doctest: +WINDOWS + >>> def ValidHandle(value): + ... if value == 0: + ... raise WinError() + ... return value + ... + >>> + >>> GetModuleHandle.restype = ValidHandle # doctest: +WINDOWS + >>> GetModuleHandle(None) # doctest: +WINDOWS + 486539264 + >>> GetModuleHandle("something silly") # doctest: +WINDOWS + Traceback (most recent call last): + File "", line 1, in ? + File "", line 3, in ValidHandle + WindowsError: [Errno 126] The specified module could not be found. + >>> + +``WinError`` is a function which will call Windows ``FormatMessage()`` api to +get the string representation of an error code, and *returns* an exception. +``WinError`` takes an optional error code parameter, if no one is used, it calls +:func:`GetLastError` to retrieve it. + +Please note that a much more powerful error checking mechanism is available +through the :attr:`errcheck` attribute; see the reference manual for details. + + +.. _ctypes-passing-pointers: + +Passing pointers (or: passing parameters by reference) +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Sometimes a C api function expects a *pointer* to a data type as parameter, +probably to write into the corresponding location, or if the data is too large +to be passed by value. This is also known as *passing parameters by reference*. + +``ctypes`` exports the :func:`byref` function which is used to pass parameters +by reference. The same effect can be achieved with the ``pointer`` function, +although ``pointer`` does a lot more work since it constructs a real pointer +object, so it is faster to use :func:`byref` if you don't need the pointer +object in Python itself:: + + >>> i = c_int() + >>> f = c_float() + >>> s = create_string_buffer('\000' * 32) + >>> print i.value, f.value, repr(s.value) + 0 0.0 '' + >>> libc.sscanf("1 3.14 Hello", "%d %f %s", + ... byref(i), byref(f), s) + 3 + >>> print i.value, f.value, repr(s.value) + 1 3.1400001049 'Hello' + >>> + + +.. _ctypes-structures-unions: + +Structures and unions +^^^^^^^^^^^^^^^^^^^^^ + +Structures and unions must derive from the :class:`Structure` and :class:`Union` +base classes which are defined in the ``ctypes`` module. Each subclass must +define a :attr:`_fields_` attribute. :attr:`_fields_` must be a list of +*2-tuples*, containing a *field name* and a *field type*. + +The field type must be a ``ctypes`` type like :class:`c_int`, or any other +derived ``ctypes`` type: structure, union, array, pointer. + +Here is a simple example of a POINT structure, which contains two integers named +``x`` and ``y``, and also shows how to initialize a structure in the +constructor:: + + >>> from ctypes import * + >>> class POINT(Structure): + ... _fields_ = [("x", c_int), + ... ("y", c_int)] + ... + >>> point = POINT(10, 20) + >>> print point.x, point.y + 10 20 + >>> point = POINT(y=5) + >>> print point.x, point.y + 0 5 + >>> POINT(1, 2, 3) + Traceback (most recent call last): + File "", line 1, in ? + ValueError: too many initializers + >>> + +You can, however, build much more complicated structures. Structures can itself +contain other structures by using a structure as a field type. + +Here is a RECT structure which contains two POINTs named ``upperleft`` and +``lowerright`` :: + + >>> class RECT(Structure): + ... _fields_ = [("upperleft", POINT), + ... ("lowerright", POINT)] + ... + >>> rc = RECT(point) + >>> print rc.upperleft.x, rc.upperleft.y + 0 5 + >>> print rc.lowerright.x, rc.lowerright.y + 0 0 + >>> + +Nested structures can also be initialized in the constructor in several ways:: + + >>> r = RECT(POINT(1, 2), POINT(3, 4)) + >>> r = RECT((1, 2), (3, 4)) + +Fields descriptors can be retrieved from the *class*, they are useful for +debugging because they can provide useful information:: + + >>> print POINT.x + + >>> print POINT.y + + >>> + + +.. _ctypes-structureunion-alignment-byte-order: + +Structure/union alignment and byte order +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +By default, Structure and Union fields are aligned in the same way the C +compiler does it. It is possible to override this behaviour be specifying a +:attr:`_pack_` class attribute in the subclass definition. This must be set to a +positive integer and specifies the maximum alignment for the fields. This is +what ``#pragma pack(n)`` also does in MSVC. + +``ctypes`` uses the native byte order for Structures and Unions. To build +structures with non-native byte order, you can use one of the +BigEndianStructure, LittleEndianStructure, BigEndianUnion, and LittleEndianUnion +base classes. These classes cannot contain pointer fields. + + +.. _ctypes-bit-fields-in-structures-unions: + +Bit fields in structures and unions +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +It is possible to create structures and unions containing bit fields. Bit fields +are only possible for integer fields, the bit width is specified as the third +item in the :attr:`_fields_` tuples:: + + >>> class Int(Structure): + ... _fields_ = [("first_16", c_int, 16), + ... ("second_16", c_int, 16)] + ... + >>> print Int.first_16 + + >>> print Int.second_16 + + >>> + + +.. _ctypes-arrays: + +Arrays +^^^^^^ + +Arrays are sequences, containing a fixed number of instances of the same type. + +The recommended way to create array types is by multiplying a data type with a +positive integer:: + + TenPointsArrayType = POINT * 10 + +Here is an example of an somewhat artifical data type, a structure containing 4 +POINTs among other stuff:: + + >>> from ctypes import * + >>> class POINT(Structure): + ... _fields_ = ("x", c_int), ("y", c_int) + ... + >>> class MyStruct(Structure): + ... _fields_ = [("a", c_int), + ... ("b", c_float), + ... ("point_array", POINT * 4)] + >>> + >>> print len(MyStruct().point_array) + 4 + >>> + +Instances are created in the usual way, by calling the class:: + + arr = TenPointsArrayType() + for pt in arr: + print pt.x, pt.y + +The above code print a series of ``0 0`` lines, because the array contents is +initialized to zeros. + +Initializers of the correct type can also be specified:: + + >>> from ctypes import * + >>> TenIntegers = c_int * 10 + >>> ii = TenIntegers(1, 2, 3, 4, 5, 6, 7, 8, 9, 10) + >>> print ii + + >>> for i in ii: print i, + ... + 1 2 3 4 5 6 7 8 9 10 + >>> + + +.. _ctypes-pointers: + +Pointers +^^^^^^^^ + +Pointer instances are created by calling the ``pointer`` function on a +``ctypes`` type:: + + >>> from ctypes import * + >>> i = c_int(42) + >>> pi = pointer(i) + >>> + +Pointer instances have a ``contents`` attribute which returns the object to +which the pointer points, the ``i`` object above:: + + >>> pi.contents + c_long(42) + >>> + +Note that ``ctypes`` does not have OOR (original object return), it constructs a +new, equivalent object each time you retrieve an attribute:: + + >>> pi.contents is i + False + >>> pi.contents is pi.contents + False + >>> + +Assigning another :class:`c_int` instance to the pointer's contents attribute +would cause the pointer to point to the memory location where this is stored:: + + >>> i = c_int(99) + >>> pi.contents = i + >>> pi.contents + c_long(99) + >>> + +Pointer instances can also be indexed with integers:: + + >>> pi[0] + 99 + >>> + +Assigning to an integer index changes the pointed to value:: + + >>> print i + c_long(99) + >>> pi[0] = 22 + >>> print i + c_long(22) + >>> + +It is also possible to use indexes different from 0, but you must know what +you're doing, just as in C: You can access or change arbitrary memory locations. +Generally you only use this feature if you receive a pointer from a C function, +and you *know* that the pointer actually points to an array instead of a single +item. + +Behind the scenes, the ``pointer`` function does more than simply create pointer +instances, it has to create pointer *types* first. This is done with the +``POINTER`` function, which accepts any ``ctypes`` type, and returns a new +type:: + + >>> PI = POINTER(c_int) + >>> PI + + >>> PI(42) + Traceback (most recent call last): + File "", line 1, in ? + TypeError: expected c_long instead of int + >>> PI(c_int(42)) + + >>> + +Calling the pointer type without an argument creates a ``NULL`` pointer. +``NULL`` pointers have a ``False`` boolean value:: + + >>> null_ptr = POINTER(c_int)() + >>> print bool(null_ptr) + False + >>> + +``ctypes`` checks for ``NULL`` when dereferencing pointers (but dereferencing +non-\ ``NULL`` pointers would crash Python):: + + >>> null_ptr[0] + Traceback (most recent call last): + .... + ValueError: NULL pointer access + >>> + + >>> null_ptr[0] = 1234 + Traceback (most recent call last): + .... + ValueError: NULL pointer access + >>> + + +.. _ctypes-type-conversions: + +Type conversions +^^^^^^^^^^^^^^^^ + +Usually, ctypes does strict type checking. This means, if you have +``POINTER(c_int)`` in the :attr:`argtypes` list of a function or as the type of +a member field in a structure definition, only instances of exactly the same +type are accepted. There are some exceptions to this rule, where ctypes accepts +other objects. For example, you can pass compatible array instances instead of +pointer types. So, for ``POINTER(c_int)``, ctypes accepts an array of c_int:: + + >>> class Bar(Structure): + ... _fields_ = [("count", c_int), ("values", POINTER(c_int))] + ... + >>> bar = Bar() + >>> bar.values = (c_int * 3)(1, 2, 3) + >>> bar.count = 3 + >>> for i in range(bar.count): + ... print bar.values[i] + ... + 1 + 2 + 3 + >>> + +To set a POINTER type field to ``NULL``, you can assign ``None``:: + + >>> bar.values = None + >>> + +XXX list other conversions... + +Sometimes you have instances of incompatible types. In ``C``, you can cast one +type into another type. ``ctypes`` provides a ``cast`` function which can be +used in the same way. The ``Bar`` structure defined above accepts +``POINTER(c_int)`` pointers or :class:`c_int` arrays for its ``values`` field, +but not instances of other types:: + + >>> bar.values = (c_byte * 4)() + Traceback (most recent call last): + File "", line 1, in ? + TypeError: incompatible types, c_byte_Array_4 instance instead of LP_c_long instance + >>> + +For these cases, the ``cast`` function is handy. + +The ``cast`` function can be used to cast a ctypes instance into a pointer to a +different ctypes data type. ``cast`` takes two parameters, a ctypes object that +is or can be converted to a pointer of some kind, and a ctypes pointer type. It +returns an instance of the second argument, which references the same memory +block as the first argument:: + + >>> a = (c_byte * 4)() + >>> cast(a, POINTER(c_int)) + + >>> + +So, ``cast`` can be used to assign to the ``values`` field of ``Bar`` the +structure:: + + >>> bar = Bar() + >>> bar.values = cast((c_byte * 4)(), POINTER(c_int)) + >>> print bar.values[0] + 0 + >>> + + +.. _ctypes-incomplete-types: + +Incomplete Types +^^^^^^^^^^^^^^^^ + +*Incomplete Types* are structures, unions or arrays whose members are not yet +specified. In C, they are specified by forward declarations, which are defined +later:: + + struct cell; /* forward declaration */ + + struct { + char *name; + struct cell *next; + } cell; + +The straightforward translation into ctypes code would be this, but it does not +work:: + + >>> class cell(Structure): + ... _fields_ = [("name", c_char_p), + ... ("next", POINTER(cell))] + ... + Traceback (most recent call last): + File "", line 1, in ? + File "", line 2, in cell + NameError: name 'cell' is not defined + >>> + +because the new ``class cell`` is not available in the class statement itself. +In ``ctypes``, we can define the ``cell`` class and set the :attr:`_fields_` +attribute later, after the class statement:: + + >>> from ctypes import * + >>> class cell(Structure): + ... pass + ... + >>> cell._fields_ = [("name", c_char_p), + ... ("next", POINTER(cell))] + >>> + +Lets try it. We create two instances of ``cell``, and let them point to each +other, and finally follow the pointer chain a few times:: + + >>> c1 = cell() + >>> c1.name = "foo" + >>> c2 = cell() + >>> c2.name = "bar" + >>> c1.next = pointer(c2) + >>> c2.next = pointer(c1) + >>> p = c1 + >>> for i in range(8): + ... print p.name, + ... p = p.next[0] + ... + foo bar foo bar foo bar foo bar + >>> + + +.. _ctypes-callback-functions: + +Callback functions +^^^^^^^^^^^^^^^^^^ + +``ctypes`` allows to create C callable function pointers from Python callables. +These are sometimes called *callback functions*. + +First, you must create a class for the callback function, the class knows the +calling convention, the return type, and the number and types of arguments this +function will receive. + +The CFUNCTYPE factory function creates types for callback functions using the +normal cdecl calling convention, and, on Windows, the WINFUNCTYPE factory +function creates types for callback functions using the stdcall calling +convention. + +Both of these factory functions are called with the result type as first +argument, and the callback functions expected argument types as the remaining +arguments. + +I will present an example here which uses the standard C library's :func:`qsort` +function, this is used to sort items with the help of a callback function. +:func:`qsort` will be used to sort an array of integers:: + + >>> IntArray5 = c_int * 5 + >>> ia = IntArray5(5, 1, 7, 33, 99) + >>> qsort = libc.qsort + >>> qsort.restype = None + >>> + +:func:`qsort` must be called with a pointer to the data to sort, the number of +items in the data array, the size of one item, and a pointer to the comparison +function, the callback. The callback will then be called with two pointers to +items, and it must return a negative integer if the first item is smaller than +the second, a zero if they are equal, and a positive integer else. + +So our callback function receives pointers to integers, and must return an +integer. First we create the ``type`` for the callback function:: + + >>> CMPFUNC = CFUNCTYPE(c_int, POINTER(c_int), POINTER(c_int)) + >>> + +For the first implementation of the callback function, we simply print the +arguments we get, and return 0 (incremental development ;-):: + + >>> def py_cmp_func(a, b): + ... print "py_cmp_func", a, b + ... return 0 + ... + >>> + +Create the C callable callback:: + + >>> cmp_func = CMPFUNC(py_cmp_func) + >>> + +And we're ready to go:: + + >>> qsort(ia, len(ia), sizeof(c_int), cmp_func) # doctest: +WINDOWS + py_cmp_func + py_cmp_func + py_cmp_func + py_cmp_func + py_cmp_func + py_cmp_func + py_cmp_func + py_cmp_func + py_cmp_func + py_cmp_func + >>> + +We know how to access the contents of a pointer, so lets redefine our callback:: + + >>> def py_cmp_func(a, b): + ... print "py_cmp_func", a[0], b[0] + ... return 0 + ... + >>> cmp_func = CMPFUNC(py_cmp_func) + >>> + +Here is what we get on Windows:: + + >>> qsort(ia, len(ia), sizeof(c_int), cmp_func) # doctest: +WINDOWS + py_cmp_func 7 1 + py_cmp_func 33 1 + py_cmp_func 99 1 + py_cmp_func 5 1 + py_cmp_func 7 5 + py_cmp_func 33 5 + py_cmp_func 99 5 + py_cmp_func 7 99 + py_cmp_func 33 99 + py_cmp_func 7 33 + >>> + +It is funny to see that on linux the sort function seems to work much more +efficient, it is doing less comparisons:: + + >>> qsort(ia, len(ia), sizeof(c_int), cmp_func) # doctest: +LINUX + py_cmp_func 5 1 + py_cmp_func 33 99 + py_cmp_func 7 33 + py_cmp_func 5 7 + py_cmp_func 1 7 + >>> + +Ah, we're nearly done! The last step is to actually compare the two items and +return a useful result:: + + >>> def py_cmp_func(a, b): + ... print "py_cmp_func", a[0], b[0] + ... return a[0] - b[0] + ... + >>> + +Final run on Windows:: + + >>> qsort(ia, len(ia), sizeof(c_int), CMPFUNC(py_cmp_func)) # doctest: +WINDOWS + py_cmp_func 33 7 + py_cmp_func 99 33 + py_cmp_func 5 99 + py_cmp_func 1 99 + py_cmp_func 33 7 + py_cmp_func 1 33 + py_cmp_func 5 33 + py_cmp_func 5 7 + py_cmp_func 1 7 + py_cmp_func 5 1 + >>> + +and on Linux:: + + >>> qsort(ia, len(ia), sizeof(c_int), CMPFUNC(py_cmp_func)) # doctest: +LINUX + py_cmp_func 5 1 + py_cmp_func 33 99 + py_cmp_func 7 33 + py_cmp_func 1 7 + py_cmp_func 5 7 + >>> + +It is quite interesting to see that the Windows :func:`qsort` function needs +more comparisons than the linux version! + +As we can easily check, our array is sorted now:: + + >>> for i in ia: print i, + ... + 1 5 7 33 99 + >>> + +**Important note for callback functions:** + +Make sure you keep references to CFUNCTYPE objects as long as they are used from +C code. ``ctypes`` doesn't, and if you don't, they may be garbage collected, +crashing your program when a callback is made. + + +.. _ctypes-accessing-values-exported-from-dlls: + +Accessing values exported from dlls +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Sometimes, a dll not only exports functions, it also exports variables. An +example in the Python library itself is the ``Py_OptimizeFlag``, an integer set +to 0, 1, or 2, depending on the :option:`-O` or :option:`-OO` flag given on +startup. + +``ctypes`` can access values like this with the :meth:`in_dll` class methods of +the type. *pythonapi* is a predefined symbol giving access to the Python C +api:: + + >>> opt_flag = c_int.in_dll(pythonapi, "Py_OptimizeFlag") + >>> print opt_flag + c_long(0) + >>> + +If the interpreter would have been started with :option:`-O`, the sample would +have printed ``c_long(1)``, or ``c_long(2)`` if :option:`-OO` would have been +specified. + +An extended example which also demonstrates the use of pointers accesses the +``PyImport_FrozenModules`` pointer exported by Python. + +Quoting the Python docs: *This pointer is initialized to point to an array of +"struct _frozen" records, terminated by one whose members are all NULL or zero. +When a frozen module is imported, it is searched in this table. Third-party code +could play tricks with this to provide a dynamically created collection of +frozen modules.* + +So manipulating this pointer could even prove useful. To restrict the example +size, we show only how this table can be read with ``ctypes``:: + + >>> from ctypes import * + >>> + >>> class struct_frozen(Structure): + ... _fields_ = [("name", c_char_p), + ... ("code", POINTER(c_ubyte)), + ... ("size", c_int)] + ... + >>> + +We have defined the ``struct _frozen`` data type, so we can get the pointer to +the table:: + + >>> FrozenTable = POINTER(struct_frozen) + >>> table = FrozenTable.in_dll(pythonapi, "PyImport_FrozenModules") + >>> + +Since ``table`` is a ``pointer`` to the array of ``struct_frozen`` records, we +can iterate over it, but we just have to make sure that our loop terminates, +because pointers have no size. Sooner or later it would probably crash with an +access violation or whatever, so it's better to break out of the loop when we +hit the NULL entry:: + + >>> for item in table: + ... print item.name, item.size + ... if item.name is None: + ... break + ... + __hello__ 104 + __phello__ -104 + __phello__.spam 104 + None 0 + >>> + +The fact that standard Python has a frozen module and a frozen package +(indicated by the negative size member) is not wellknown, it is only used for +testing. Try it out with ``import __hello__`` for example. + + +.. _ctypes-surprises: + +Surprises +^^^^^^^^^ + +There are some edges in ``ctypes`` where you may be expect something else than +what actually happens. + +Consider the following example:: + + >>> from ctypes import * + >>> class POINT(Structure): + ... _fields_ = ("x", c_int), ("y", c_int) + ... + >>> class RECT(Structure): + ... _fields_ = ("a", POINT), ("b", POINT) + ... + >>> p1 = POINT(1, 2) + >>> p2 = POINT(3, 4) + >>> rc = RECT(p1, p2) + >>> print rc.a.x, rc.a.y, rc.b.x, rc.b.y + 1 2 3 4 + >>> # now swap the two points + >>> rc.a, rc.b = rc.b, rc.a + >>> print rc.a.x, rc.a.y, rc.b.x, rc.b.y + 3 4 3 4 + >>> + +Hm. We certainly expected the last statement to print ``3 4 1 2``. What +happended? Here are the steps of the ``rc.a, rc.b = rc.b, rc.a`` line above:: + + >>> temp0, temp1 = rc.b, rc.a + >>> rc.a = temp0 + >>> rc.b = temp1 + >>> + +Note that ``temp0`` and ``temp1`` are objects still using the internal buffer of +the ``rc`` object above. So executing ``rc.a = temp0`` copies the buffer +contents of ``temp0`` into ``rc`` 's buffer. This, in turn, changes the +contents of ``temp1``. So, the last assignment ``rc.b = temp1``, doesn't have +the expected effect. + +Keep in mind that retrieving subobjects from Structure, Unions, and Arrays +doesn't *copy* the subobject, instead it retrieves a wrapper object accessing +the root-object's underlying buffer. + +Another example that may behave different from what one would expect is this:: + + >>> s = c_char_p() + >>> s.value = "abc def ghi" + >>> s.value + 'abc def ghi' + >>> s.value is s.value + False + >>> + +Why is it printing ``False``? ctypes instances are objects containing a memory +block plus some descriptors accessing the contents of the memory. Storing a +Python object in the memory block does not store the object itself, instead the +``contents`` of the object is stored. Accessing the contents again constructs a +new Python each time! + + +.. _ctypes-variable-sized-data-types: + +Variable-sized data types +^^^^^^^^^^^^^^^^^^^^^^^^^ + +``ctypes`` provides some support for variable-sized arrays and structures (this +was added in version 0.9.9.7). + +The ``resize`` function can be used to resize the memory buffer of an existing +ctypes object. The function takes the object as first argument, and the +requested size in bytes as the second argument. The memory block cannot be made +smaller than the natural memory block specified by the objects type, a +``ValueError`` is raised if this is tried:: + + >>> short_array = (c_short * 4)() + >>> print sizeof(short_array) + 8 + >>> resize(short_array, 4) + Traceback (most recent call last): + ... + ValueError: minimum size is 8 + >>> resize(short_array, 32) + >>> sizeof(short_array) + 32 + >>> sizeof(type(short_array)) + 8 + >>> + +This is nice and fine, but how would one access the additional elements +contained in this array? Since the type still only knows about 4 elements, we +get errors accessing other elements:: + + >>> short_array[:] + [0, 0, 0, 0] + >>> short_array[7] + Traceback (most recent call last): + ... + IndexError: invalid index + >>> + +Another way to use variable-sized data types with ``ctypes`` is to use the +dynamic nature of Python, and (re-)define the data type after the required size +is already known, on a case by case basis. + + +.. _ctypes-bugs-todo-non-implemented-things: + +Bugs, ToDo and non-implemented things +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Enumeration types are not implemented. You can do it easily yourself, using +:class:`c_int` as the base class. + +``long double`` is not implemented. + +.. % Local Variables: +.. % compile-command: "make.bat" +.. % End: + + +.. _ctypes-ctypes-reference: + +ctypes reference +---------------- + + +.. _ctypes-finding-shared-libraries: + +Finding shared libraries +^^^^^^^^^^^^^^^^^^^^^^^^ + +When programming in a compiled language, shared libraries are accessed when +compiling/linking a program, and when the program is run. + +The purpose of the ``find_library`` function is to locate a library in a way +similar to what the compiler does (on platforms with several versions of a +shared library the most recent should be loaded), while the ctypes library +loaders act like when a program is run, and call the runtime loader directly. + +The ``ctypes.util`` module provides a function which can help to determine the +library to load. + + +.. data:: find_library(name) + :noindex: + + Try to find a library and return a pathname. *name* is the library name without + any prefix like *lib*, suffix like ``.so``, ``.dylib`` or version number (this + is the form used for the posix linker option :option:`-l`). If no library can + be found, returns ``None``. + +The exact functionality is system dependend. + +On Linux, ``find_library`` tries to run external programs (/sbin/ldconfig, gcc, +and objdump) to find the library file. It returns the filename of the library +file. Here are sone examples:: + + >>> from ctypes.util import find_library + >>> find_library("m") + 'libm.so.6' + >>> find_library("c") + 'libc.so.6' + >>> find_library("bz2") + 'libbz2.so.1.0' + >>> + +On OS X, ``find_library`` tries several predefined naming schemes and paths to +locate the library, and returns a full pathname if successfull:: + + >>> from ctypes.util import find_library + >>> find_library("c") + '/usr/lib/libc.dylib' + >>> find_library("m") + '/usr/lib/libm.dylib' + >>> find_library("bz2") + '/usr/lib/libbz2.dylib' + >>> find_library("AGL") + '/System/Library/Frameworks/AGL.framework/AGL' + >>> + +On Windows, ``find_library`` searches along the system search path, and returns +the full pathname, but since there is no predefined naming scheme a call like +``find_library("c")`` will fail and return ``None``. + +If wrapping a shared library with ``ctypes``, it *may* be better to determine +the shared library name at development type, and hardcode that into the wrapper +module instead of using ``find_library`` to locate the library at runtime. + + +.. _ctypes-loading-shared-libraries: + +Loading shared libraries +^^^^^^^^^^^^^^^^^^^^^^^^ + +There are several ways to loaded shared libraries into the Python process. One +way is to instantiate one of the following classes: + + +.. class:: CDLL(name, mode=DEFAULT_MODE, handle=None) + + Instances of this class represent loaded shared libraries. Functions in these + libraries use the standard C calling convention, and are assumed to return + ``int``. + + +.. class:: OleDLL(name, mode=DEFAULT_MODE, handle=None) + + Windows only: Instances of this class represent loaded shared libraries, + functions in these libraries use the ``stdcall`` calling convention, and are + assumed to return the windows specific :class:`HRESULT` code. :class:`HRESULT` + values contain information specifying whether the function call failed or + succeeded, together with additional error code. If the return value signals a + failure, an :class:`WindowsError` is automatically raised. + + +.. class:: WinDLL(name, mode=DEFAULT_MODE, handle=None) + + Windows only: Instances of this class represent loaded shared libraries, + functions in these libraries use the ``stdcall`` calling convention, and are + assumed to return ``int`` by default. + + On Windows CE only the standard calling convention is used, for convenience the + :class:`WinDLL` and :class:`OleDLL` use the standard calling convention on this + platform. + +The Python GIL is released before calling any function exported by these +libraries, and reaquired afterwards. + + +.. class:: PyDLL(name, mode=DEFAULT_MODE, handle=None) + + Instances of this class behave like :class:`CDLL` instances, except that the + Python GIL is *not* released during the function call, and after the function + execution the Python error flag is checked. If the error flag is set, a Python + exception is raised. + + Thus, this is only useful to call Python C api functions directly. + +All these classes can be instantiated by calling them with at least one +argument, the pathname of the shared library. If you have an existing handle to +an already loaded shard library, it can be passed as the ``handle`` named +parameter, otherwise the underlying platforms ``dlopen`` or :meth:`LoadLibrary` +function is used to load the library into the process, and to get a handle to +it. + +The *mode* parameter can be used to specify how the library is loaded. For +details, consult the ``dlopen(3)`` manpage, on Windows, *mode* is ignored. + + +.. data:: RTLD_GLOBAL + :noindex: + + Flag to use as *mode* parameter. On platforms where this flag is not available, + it is defined as the integer zero. + + +.. data:: RTLD_LOCAL + :noindex: + + Flag to use as *mode* parameter. On platforms where this is not available, it + is the same as *RTLD_GLOBAL*. + + +.. data:: DEFAULT_MODE + :noindex: + + The default mode which is used to load shared libraries. On OSX 10.3, this is + *RTLD_GLOBAL*, otherwise it is the same as *RTLD_LOCAL*. + +Instances of these classes have no public methods, however :meth:`__getattr__` +and :meth:`__getitem__` have special behaviour: functions exported by the shared +library can be accessed as attributes of by index. Please note that both +:meth:`__getattr__` and :meth:`__getitem__` cache their result, so calling them +repeatedly returns the same object each time. + +The following public attributes are available, their name starts with an +underscore to not clash with exported function names: + + +.. attribute:: PyDLL._handle + + The system handle used to access the library. + + +.. attribute:: PyDLL._name + + The name of the library passed in the contructor. + +Shared libraries can also be loaded by using one of the prefabricated objects, +which are instances of the :class:`LibraryLoader` class, either by calling the +:meth:`LoadLibrary` method, or by retrieving the library as attribute of the +loader instance. + + +.. class:: LibraryLoader(dlltype) + + Class which loads shared libraries. ``dlltype`` should be one of the + :class:`CDLL`, :class:`PyDLL`, :class:`WinDLL`, or :class:`OleDLL` types. + + :meth:`__getattr__` has special behaviour: It allows to load a shared library by + accessing it as attribute of a library loader instance. The result is cached, + so repeated attribute accesses return the same library each time. + + +.. method:: LibraryLoader.LoadLibrary(name) + + Load a shared library into the process and return it. This method always + returns a new instance of the library. + +These prefabricated library loaders are available: + + +.. data:: cdll + :noindex: + + Creates :class:`CDLL` instances. + + +.. data:: windll + :noindex: + + Windows only: Creates :class:`WinDLL` instances. + + +.. data:: oledll + :noindex: + + Windows only: Creates :class:`OleDLL` instances. + + +.. data:: pydll + :noindex: + + Creates :class:`PyDLL` instances. + +For accessing the C Python api directly, a ready-to-use Python shared library +object is available: + + +.. data:: pythonapi + :noindex: + + An instance of :class:`PyDLL` that exposes Python C api functions as attributes. + Note that all these functions are assumed to return C ``int``, which is of + course not always the truth, so you have to assign the correct :attr:`restype` + attribute to use these functions. + + +.. _ctypes-foreign-functions: + +Foreign functions +^^^^^^^^^^^^^^^^^ + +As explained in the previous section, foreign functions can be accessed as +attributes of loaded shared libraries. The function objects created in this way +by default accept any number of arguments, accept any ctypes data instances as +arguments, and return the default result type specified by the library loader. +They are instances of a private class: + + +.. class:: _FuncPtr + + Base class for C callable foreign functions. + +Instances of foreign functions are also C compatible data types; they represent +C function pointers. + +This behaviour can be customized by assigning to special attributes of the +foreign function object. + + +.. attribute:: _FuncPtr.restype + + Assign a ctypes type to specify the result type of the foreign function. Use + ``None`` for ``void`` a function not returning anything. + + It is possible to assign a callable Python object that is not a ctypes type, in + this case the function is assumed to return a C ``int``, and the callable will + be called with this integer, allowing to do further processing or error + checking. Using this is deprecated, for more flexible postprocessing or error + checking use a ctypes data type as :attr:`restype` and assign a callable to the + :attr:`errcheck` attribute. + + +.. attribute:: _FuncPtr.argtypes + + Assign a tuple of ctypes types to specify the argument types that the function + accepts. Functions using the ``stdcall`` calling convention can only be called + with the same number of arguments as the length of this tuple; functions using + the C calling convention accept additional, unspecified arguments as well. + + When a foreign function is called, each actual argument is passed to the + :meth:`from_param` class method of the items in the :attr:`argtypes` tuple, this + method allows to adapt the actual argument to an object that the foreign + function accepts. For example, a :class:`c_char_p` item in the :attr:`argtypes` + tuple will convert a unicode string passed as argument into an byte string using + ctypes conversion rules. + + New: It is now possible to put items in argtypes which are not ctypes types, but + each item must have a :meth:`from_param` method which returns a value usable as + argument (integer, string, ctypes instance). This allows to define adapters + that can adapt custom objects as function parameters. + + +.. attribute:: _FuncPtr.errcheck + + Assign a Python function or another callable to this attribute. The callable + will be called with three or more arguments: + + +.. function:: callable(result, func, arguments) + :noindex: + + ``result`` is what the foreign function returns, as specified by the + :attr:`restype` attribute. + + ``func`` is the foreign function object itself, this allows to reuse the same + callable object to check or postprocess the results of several functions. + + ``arguments`` is a tuple containing the parameters originally passed to the + function call, this allows to specialize the behaviour on the arguments used. + + The object that this function returns will be returned from the foreign function + call, but it can also check the result value and raise an exception if the + foreign function call failed. + + +.. exception:: ArgumentError() + + This exception is raised when a foreign function call cannot convert one of the + passed arguments. + + +.. _ctypes-function-prototypes: + +Function prototypes +^^^^^^^^^^^^^^^^^^^ + +Foreign functions can also be created by instantiating function prototypes. +Function prototypes are similar to function prototypes in C; they describe a +function (return type, argument types, calling convention) without defining an +implementation. The factory functions must be called with the desired result +type and the argument types of the function. + + +.. function:: CFUNCTYPE(restype, *argtypes) + + The returned function prototype creates functions that use the standard C + calling convention. The function will release the GIL during the call. + + +.. function:: WINFUNCTYPE(restype, *argtypes) + + Windows only: The returned function prototype creates functions that use the + ``stdcall`` calling convention, except on Windows CE where :func:`WINFUNCTYPE` + is the same as :func:`CFUNCTYPE`. The function will release the GIL during the + call. + + +.. function:: PYFUNCTYPE(restype, *argtypes) + + The returned function prototype creates functions that use the Python calling + convention. The function will *not* release the GIL during the call. + +Function prototypes created by the factory functions can be instantiated in +different ways, depending on the type and number of the parameters in the call. + + +.. function:: prototype(address) + :noindex: + + Returns a foreign function at the specified address. + + +.. function:: prototype(callable) + :noindex: + + Create a C callable function (a callback function) from a Python ``callable``. + + +.. function:: prototype(func_spec[, paramflags]) + :noindex: + + Returns a foreign function exported by a shared library. ``func_spec`` must be a + 2-tuple ``(name_or_ordinal, library)``. The first item is the name of the + exported function as string, or the ordinal of the exported function as small + integer. The second item is the shared library instance. + + +.. function:: prototype(vtbl_index, name[, paramflags[, iid]]) + :noindex: + + Returns a foreign function that will call a COM method. ``vtbl_index`` is the + index into the virtual function table, a small nonnegative integer. *name* is + name of the COM method. *iid* is an optional pointer to the interface identifier + which is used in extended error reporting. + + COM methods use a special calling convention: They require a pointer to the COM + interface as first argument, in addition to those parameters that are specified + in the :attr:`argtypes` tuple. + +The optional *paramflags* parameter creates foreign function wrappers with much +more functionality than the features described above. + +*paramflags* must be a tuple of the same length as :attr:`argtypes`. + +Each item in this tuple contains further information about a parameter, it must +be a tuple containing 1, 2, or 3 items. + +The first item is an integer containing flags for the parameter: + + +.. data:: 1 + :noindex: + + Specifies an input parameter to the function. + + +.. data:: 2 + :noindex: + + Output parameter. The foreign function fills in a value. + + +.. data:: 4 + :noindex: + + Input parameter which defaults to the integer zero. + +The optional second item is the parameter name as string. If this is specified, +the foreign function can be called with named parameters. + +The optional third item is the default value for this parameter. + +This example demonstrates how to wrap the Windows ``MessageBoxA`` function so +that it supports default parameters and named arguments. The C declaration from +the windows header file is this:: + + WINUSERAPI int WINAPI + MessageBoxA( + HWND hWnd , + LPCSTR lpText, + LPCSTR lpCaption, + UINT uType); + +Here is the wrapping with ``ctypes``: + + :: + + >>> from ctypes import c_int, WINFUNCTYPE, windll + >>> from ctypes.wintypes import HWND, LPCSTR, UINT + >>> prototype = WINFUNCTYPE(c_int, HWND, LPCSTR, LPCSTR, UINT) + >>> paramflags = (1, "hwnd", 0), (1, "text", "Hi"), (1, "caption", None), (1, "flags", 0) + >>> MessageBox = prototype(("MessageBoxA", windll.user32), paramflags) + >>> + +The MessageBox foreign function can now be called in these ways:: + + >>> MessageBox() + >>> MessageBox(text="Spam, spam, spam") + >>> MessageBox(flags=2, text="foo bar") + >>> + +A second example demonstrates output parameters. The win32 ``GetWindowRect`` +function retrieves the dimensions of a specified window by copying them into +``RECT`` structure that the caller has to supply. Here is the C declaration:: + + WINUSERAPI BOOL WINAPI + GetWindowRect( + HWND hWnd, + LPRECT lpRect); + +Here is the wrapping with ``ctypes``: + + :: + + >>> from ctypes import POINTER, WINFUNCTYPE, windll, WinError + >>> from ctypes.wintypes import BOOL, HWND, RECT + >>> prototype = WINFUNCTYPE(BOOL, HWND, POINTER(RECT)) + >>> paramflags = (1, "hwnd"), (2, "lprect") + >>> GetWindowRect = prototype(("GetWindowRect", windll.user32), paramflags) + >>> + +Functions with output parameters will automatically return the output parameter +value if there is a single one, or a tuple containing the output parameter +values when there are more than one, so the GetWindowRect function now returns a +RECT instance, when called. + +Output parameters can be combined with the :attr:`errcheck` protocol to do +further output processing and error checking. The win32 ``GetWindowRect`` api +function returns a ``BOOL`` to signal success or failure, so this function could +do the error checking, and raises an exception when the api call failed:: + + >>> def errcheck(result, func, args): + ... if not result: + ... raise WinError() + ... return args + >>> GetWindowRect.errcheck = errcheck + >>> + +If the :attr:`errcheck` function returns the argument tuple it receives +unchanged, ``ctypes`` continues the normal processing it does on the output +parameters. If you want to return a tuple of window coordinates instead of a +``RECT`` instance, you can retrieve the fields in the function and return them +instead, the normal processing will no longer take place:: + + >>> def errcheck(result, func, args): + ... if not result: + ... raise WinError() + ... rc = args[1] + ... return rc.left, rc.top, rc.bottom, rc.right + >>> + >>> GetWindowRect.errcheck = errcheck + >>> + + +.. _ctypes-utility-functions: + +Utility functions +^^^^^^^^^^^^^^^^^ + + +.. function:: addressof(obj) + + Returns the address of the memory buffer as integer. ``obj`` must be an + instance of a ctypes type. + + +.. function:: alignment(obj_or_type) + + Returns the alignment requirements of a ctypes type. ``obj_or_type`` must be a + ctypes type or instance. + + +.. function:: byref(obj) + + Returns a light-weight pointer to ``obj``, which must be an instance of a ctypes + type. The returned object can only be used as a foreign function call parameter. + It behaves similar to ``pointer(obj)``, but the construction is a lot faster. + + +.. function:: cast(obj, type) + + This function is similar to the cast operator in C. It returns a new instance of + ``type`` which points to the same memory block as ``obj``. ``type`` must be a + pointer type, and ``obj`` must be an object that can be interpreted as a + pointer. + + +.. function:: create_string_buffer(init_or_size[, size]) + + This function creates a mutable character buffer. The returned object is a + ctypes array of :class:`c_char`. + + ``init_or_size`` must be an integer which specifies the size of the array, or a + string which will be used to initialize the array items. + + If a string is specified as first argument, the buffer is made one item larger + than the length of the string so that the last element in the array is a NUL + termination character. An integer can be passed as second argument which allows + to specify the size of the array if the length of the string should not be used. + + If the first parameter is a unicode string, it is converted into an 8-bit string + according to ctypes conversion rules. + + +.. function:: create_unicode_buffer(init_or_size[, size]) + + This function creates a mutable unicode character buffer. The returned object is + a ctypes array of :class:`c_wchar`. + + ``init_or_size`` must be an integer which specifies the size of the array, or a + unicode string which will be used to initialize the array items. + + If a unicode string is specified as first argument, the buffer is made one item + larger than the length of the string so that the last element in the array is a + NUL termination character. An integer can be passed as second argument which + allows to specify the size of the array if the length of the string should not + be used. + + If the first parameter is a 8-bit string, it is converted into an unicode string + according to ctypes conversion rules. + + +.. function:: DllCanUnloadNow() + + Windows only: This function is a hook which allows to implement inprocess COM + servers with ctypes. It is called from the DllCanUnloadNow function that the + _ctypes extension dll exports. + + +.. function:: DllGetClassObject() + + Windows only: This function is a hook which allows to implement inprocess COM + servers with ctypes. It is called from the DllGetClassObject function that the + ``_ctypes`` extension dll exports. + + +.. function:: FormatError([code]) + + Windows only: Returns a textual description of the error code. If no error code + is specified, the last error code is used by calling the Windows api function + GetLastError. + + +.. function:: GetLastError() + + Windows only: Returns the last error code set by Windows in the calling thread. + + +.. function:: memmove(dst, src, count) + + Same as the standard C memmove library function: copies *count* bytes from + ``src`` to *dst*. *dst* and ``src`` must be integers or ctypes instances that + can be converted to pointers. + + +.. function:: memset(dst, c, count) + + Same as the standard C memset library function: fills the memory block at + address *dst* with *count* bytes of value *c*. *dst* must be an integer + specifying an address, or a ctypes instance. + + +.. function:: POINTER(type) + + This factory function creates and returns a new ctypes pointer type. Pointer + types are cached an reused internally, so calling this function repeatedly is + cheap. type must be a ctypes type. + + +.. function:: pointer(obj) + + This function creates a new pointer instance, pointing to ``obj``. The returned + object is of the type POINTER(type(obj)). + + Note: If you just want to pass a pointer to an object to a foreign function + call, you should use ``byref(obj)`` which is much faster. + + +.. function:: resize(obj, size) + + This function resizes the internal memory buffer of obj, which must be an + instance of a ctypes type. It is not possible to make the buffer smaller than + the native size of the objects type, as given by sizeof(type(obj)), but it is + possible to enlarge the buffer. + + +.. function:: set_conversion_mode(encoding, errors) + + This function sets the rules that ctypes objects use when converting between + 8-bit strings and unicode strings. encoding must be a string specifying an + encoding, like ``'utf-8'`` or ``'mbcs'``, errors must be a string specifying the + error handling on encoding/decoding errors. Examples of possible values are + ``"strict"``, ``"replace"``, or ``"ignore"``. + + ``set_conversion_mode`` returns a 2-tuple containing the previous conversion + rules. On windows, the initial conversion rules are ``('mbcs', 'ignore')``, on + other systems ``('ascii', 'strict')``. + + +.. function:: sizeof(obj_or_type) + + Returns the size in bytes of a ctypes type or instance memory buffer. Does the + same as the C ``sizeof()`` function. + + +.. function:: string_at(address[, size]) + + This function returns the string starting at memory address address. If size + is specified, it is used as size, otherwise the string is assumed to be + zero-terminated. + + +.. function:: WinError(code=None, descr=None) + + Windows only: this function is probably the worst-named thing in ctypes. It + creates an instance of WindowsError. If *code* is not specified, + ``GetLastError`` is called to determine the error code. If ``descr`` is not + spcified, :func:`FormatError` is called to get a textual description of the + error. + + +.. function:: wstring_at(address) + + This function returns the wide character string starting at memory address + ``address`` as unicode string. If ``size`` is specified, it is used as the + number of characters of the string, otherwise the string is assumed to be + zero-terminated. + + +.. _ctypes-data-types: + +Data types +^^^^^^^^^^ + + +.. class:: _CData + + This non-public class is the common base class of all ctypes data types. Among + other things, all ctypes type instances contain a memory block that hold C + compatible data; the address of the memory block is returned by the + ``addressof()`` helper function. Another instance variable is exposed as + :attr:`_objects`; this contains other Python objects that need to be kept alive + in case the memory block contains pointers. + +Common methods of ctypes data types, these are all class methods (to be exact, +they are methods of the metaclass): + + +.. method:: _CData.from_address(address) + + This method returns a ctypes type instance using the memory specified by address + which must be an integer. + + +.. method:: _CData.from_param(obj) + + This method adapts obj to a ctypes type. It is called with the actual object + used in a foreign function call, when the type is present in the foreign + functions :attr:`argtypes` tuple; it must return an object that can be used as + function call parameter. + + All ctypes data types have a default implementation of this classmethod, + normally it returns ``obj`` if that is an instance of the type. Some types + accept other objects as well. + + +.. method:: _CData.in_dll(library, name) + + This method returns a ctypes type instance exported by a shared library. *name* + is the name of the symbol that exports the data, *library* is the loaded shared + library. + +Common instance variables of ctypes data types: + + +.. attribute:: _CData._b_base_ + + Sometimes ctypes data instances do not own the memory block they contain, + instead they share part of the memory block of a base object. The + :attr:`_b_base_` readonly member is the root ctypes object that owns the memory + block. + + +.. attribute:: _CData._b_needsfree_ + + This readonly variable is true when the ctypes data instance has allocated the + memory block itself, false otherwise. + + +.. attribute:: _CData._objects + + This member is either ``None`` or a dictionary containing Python objects that + need to be kept alive so that the memory block contents is kept valid. This + object is only exposed for debugging; never modify the contents of this + dictionary. + + +.. _ctypes-fundamental-data-types-2: + +Fundamental data types +^^^^^^^^^^^^^^^^^^^^^^ + + +.. class:: _SimpleCData + + This non-public class is the base class of all fundamental ctypes data types. It + is mentioned here because it contains the common attributes of the fundamental + ctypes data types. ``_SimpleCData`` is a subclass of ``_CData``, so it inherits + their methods and attributes. + +Instances have a single attribute: + + +.. attribute:: _SimpleCData.value + + This attribute contains the actual value of the instance. For integer and + pointer types, it is an integer, for character types, it is a single character + string, for character pointer types it is a Python string or unicode string. + + When the ``value`` attribute is retrieved from a ctypes instance, usually a new + object is returned each time. ``ctypes`` does *not* implement original object + return, always a new object is constructed. The same is true for all other + ctypes object instances. + +Fundamental data types, when returned as foreign function call results, or, for +example, by retrieving structure field members or array items, are transparently +converted to native Python types. In other words, if a foreign function has a +:attr:`restype` of :class:`c_char_p`, you will always receive a Python string, +*not* a :class:`c_char_p` instance. + +Subclasses of fundamental data types do *not* inherit this behaviour. So, if a +foreign functions :attr:`restype` is a subclass of :class:`c_void_p`, you will +receive an instance of this subclass from the function call. Of course, you can +get the value of the pointer by accessing the ``value`` attribute. + +These are the fundamental ctypes data types: + + +.. class:: c_byte + + Represents the C signed char datatype, and interprets the value as small + integer. The constructor accepts an optional integer initializer; no overflow + checking is done. + + +.. class:: c_char + + Represents the C char datatype, and interprets the value as a single character. + The constructor accepts an optional string initializer, the length of the string + must be exactly one character. + + +.. class:: c_char_p + + Represents the C char \* datatype, which must be a pointer to a zero-terminated + string. The constructor accepts an integer address, or a string. + + +.. class:: c_double + + Represents the C double datatype. The constructor accepts an optional float + initializer. + + +.. class:: c_float + + Represents the C double datatype. The constructor accepts an optional float + initializer. + + +.. class:: c_int + + Represents the C signed int datatype. The constructor accepts an optional + integer initializer; no overflow checking is done. On platforms where + ``sizeof(int) == sizeof(long)`` it is an alias to :class:`c_long`. + + +.. class:: c_int8 + + Represents the C 8-bit ``signed int`` datatype. Usually an alias for + :class:`c_byte`. + + +.. class:: c_int16 + + Represents the C 16-bit signed int datatype. Usually an alias for + :class:`c_short`. + + +.. class:: c_int32 + + Represents the C 32-bit signed int datatype. Usually an alias for + :class:`c_int`. + + +.. class:: c_int64 + + Represents the C 64-bit ``signed int`` datatype. Usually an alias for + :class:`c_longlong`. + + +.. class:: c_long + + Represents the C ``signed long`` datatype. The constructor accepts an optional + integer initializer; no overflow checking is done. + + +.. class:: c_longlong + + Represents the C ``signed long long`` datatype. The constructor accepts an + optional integer initializer; no overflow checking is done. + + +.. class:: c_short + + Represents the C ``signed short`` datatype. The constructor accepts an optional + integer initializer; no overflow checking is done. + + +.. class:: c_size_t + + Represents the C ``size_t`` datatype. + + +.. class:: c_ubyte + + Represents the C ``unsigned char`` datatype, it interprets the value as small + integer. The constructor accepts an optional integer initializer; no overflow + checking is done. + + +.. class:: c_uint + + Represents the C ``unsigned int`` datatype. The constructor accepts an optional + integer initializer; no overflow checking is done. On platforms where + ``sizeof(int) == sizeof(long)`` it is an alias for :class:`c_ulong`. + + +.. class:: c_uint8 + + Represents the C 8-bit unsigned int datatype. Usually an alias for + :class:`c_ubyte`. + + +.. class:: c_uint16 + + Represents the C 16-bit unsigned int datatype. Usually an alias for + :class:`c_ushort`. + + +.. class:: c_uint32 + + Represents the C 32-bit unsigned int datatype. Usually an alias for + :class:`c_uint`. + + +.. class:: c_uint64 + + Represents the C 64-bit unsigned int datatype. Usually an alias for + :class:`c_ulonglong`. + + +.. class:: c_ulong + + Represents the C ``unsigned long`` datatype. The constructor accepts an optional + integer initializer; no overflow checking is done. + + +.. class:: c_ulonglong + + Represents the C ``unsigned long long`` datatype. The constructor accepts an + optional integer initializer; no overflow checking is done. + + +.. class:: c_ushort + + Represents the C ``unsigned short`` datatype. The constructor accepts an + optional integer initializer; no overflow checking is done. + + +.. class:: c_void_p + + Represents the C ``void *`` type. The value is represented as integer. The + constructor accepts an optional integer initializer. + + +.. class:: c_wchar + + Represents the C ``wchar_t`` datatype, and interprets the value as a single + character unicode string. The constructor accepts an optional string + initializer, the length of the string must be exactly one character. + + +.. class:: c_wchar_p + + Represents the C ``wchar_t *`` datatype, which must be a pointer to a + zero-terminated wide character string. The constructor accepts an integer + address, or a string. + + +.. class:: c_bool + + Represent the C ``bool`` datatype (more accurately, _Bool from C99). Its value + can be True or False, and the constructor accepts any object that has a truth + value. + + .. versionadded:: 2.6 + + +.. class:: HRESULT + + Windows only: Represents a :class:`HRESULT` value, which contains success or + error information for a function or method call. + + +.. class:: py_object + + Represents the C ``PyObject *`` datatype. Calling this without an argument + creates a ``NULL`` ``PyObject *`` pointer. + +The ``ctypes.wintypes`` module provides quite some other Windows specific data +types, for example ``HWND``, ``WPARAM``, or ``DWORD``. Some useful structures +like ``MSG`` or ``RECT`` are also defined. + + +.. _ctypes-structured-data-types: + +Structured data types +^^^^^^^^^^^^^^^^^^^^^ + + +.. class:: Union(*args, **kw) + + Abstract base class for unions in native byte order. + + +.. class:: BigEndianStructure(*args, **kw) + + Abstract base class for structures in *big endian* byte order. + + +.. class:: LittleEndianStructure(*args, **kw) + + Abstract base class for structures in *little endian* byte order. + +Structures with non-native byte order cannot contain pointer type fields, or any +other data types containing pointer type fields. + + +.. class:: Structure(*args, **kw) + + Abstract base class for structures in *native* byte order. + +Concrete structure and union types must be created by subclassing one of these +types, and at least define a :attr:`_fields_` class variable. ``ctypes`` will +create descriptors which allow reading and writing the fields by direct +attribute accesses. These are the + + +.. attribute:: Structure._fields_ + + A sequence defining the structure fields. The items must be 2-tuples or + 3-tuples. The first item is the name of the field, the second item specifies + the type of the field; it can be any ctypes data type. + + For integer type fields like :class:`c_int`, a third optional item can be given. + It must be a small positive integer defining the bit width of the field. + + Field names must be unique within one structure or union. This is not checked, + only one field can be accessed when names are repeated. + + It is possible to define the :attr:`_fields_` class variable *after* the class + statement that defines the Structure subclass, this allows to create data types + that directly or indirectly reference themselves:: + + class List(Structure): + pass + List._fields_ = [("pnext", POINTER(List)), + ... + ] + + The :attr:`_fields_` class variable must, however, be defined before the type is + first used (an instance is created, ``sizeof()`` is called on it, and so on). + Later assignments to the :attr:`_fields_` class variable will raise an + AttributeError. + + Structure and union subclass constructors accept both positional and named + arguments. Positional arguments are used to initialize the fields in the same + order as they appear in the :attr:`_fields_` definition, named arguments are + used to initialize the fields with the corresponding name. + + It is possible to defined sub-subclasses of structure types, they inherit the + fields of the base class plus the :attr:`_fields_` defined in the sub-subclass, + if any. + + +.. attribute:: Structure._pack_ + + An optional small integer that allows to override the alignment of structure + fields in the instance. :attr:`_pack_` must already be defined when + :attr:`_fields_` is assigned, otherwise it will have no effect. + + +.. attribute:: Structure._anonymous_ + + An optional sequence that lists the names of unnamed (anonymous) fields. + ``_anonymous_`` must be already defined when :attr:`_fields_` is assigned, + otherwise it will have no effect. + + The fields listed in this variable must be structure or union type fields. + ``ctypes`` will create descriptors in the structure type that allows to access + the nested fields directly, without the need to create the structure or union + field. + + Here is an example type (Windows):: + + class _U(Union): + _fields_ = [("lptdesc", POINTER(TYPEDESC)), + ("lpadesc", POINTER(ARRAYDESC)), + ("hreftype", HREFTYPE)] + + class TYPEDESC(Structure): + _fields_ = [("u", _U), + ("vt", VARTYPE)] + + _anonymous_ = ("u",) + + The ``TYPEDESC`` structure describes a COM data type, the ``vt`` field specifies + which one of the union fields is valid. Since the ``u`` field is defined as + anonymous field, it is now possible to access the members directly off the + TYPEDESC instance. ``td.lptdesc`` and ``td.u.lptdesc`` are equivalent, but the + former is faster since it does not need to create a temporary union instance:: + + td = TYPEDESC() + td.vt = VT_PTR + td.lptdesc = POINTER(some_type) + td.u.lptdesc = POINTER(some_type) + +It is possible to defined sub-subclasses of structures, they inherit the fields +of the base class. If the subclass definition has a separate :attr:`_fields_` +variable, the fields specified in this are appended to the fields of the base +class. + +Structure and union constructors accept both positional and keyword arguments. +Positional arguments are used to initialize member fields in the same order as +they are appear in :attr:`_fields_`. Keyword arguments in the constructor are +interpreted as attribute assignments, so they will initialize :attr:`_fields_` +with the same name, or create new attributes for names not present in +:attr:`_fields_`. + + +.. _ctypes-arrays-pointers: + +Arrays and pointers +^^^^^^^^^^^^^^^^^^^ + +Not yet written - please see the sections :ref:`ctypes-pointers` and +section :ref:`ctypes-arrays` in the tutorial. + diff --git a/Doc/library/curses.ascii.rst b/Doc/library/curses.ascii.rst new file mode 100644 index 0000000..0a45c2a --- /dev/null +++ b/Doc/library/curses.ascii.rst @@ -0,0 +1,228 @@ + +:mod:`curses.ascii` --- Utilities for ASCII characters +====================================================== + +.. module:: curses.ascii + :synopsis: Constants and set-membership functions for ASCII characters. +.. moduleauthor:: Eric S. Raymond +.. sectionauthor:: Eric S. Raymond + + +.. versionadded:: 1.6 + +The :mod:`curses.ascii` module supplies name constants for ASCII characters and +functions to test membership in various ASCII character classes. The constants +supplied are names for control characters as follows: + ++--------------+----------------------------------------------+ +| Name | Meaning | ++==============+==============================================+ +| :const:`NUL` | | ++--------------+----------------------------------------------+ +| :const:`SOH` | Start of heading, console interrupt | ++--------------+----------------------------------------------+ +| :const:`STX` | Start of text | ++--------------+----------------------------------------------+ +| :const:`ETX` | End of text | ++--------------+----------------------------------------------+ +| :const:`EOT` | End of transmission | ++--------------+----------------------------------------------+ +| :const:`ENQ` | Enquiry, goes with :const:`ACK` flow control | ++--------------+----------------------------------------------+ +| :const:`ACK` | Acknowledgement | ++--------------+----------------------------------------------+ +| :const:`BEL` | Bell | ++--------------+----------------------------------------------+ +| :const:`BS` | Backspace | ++--------------+----------------------------------------------+ +| :const:`TAB` | Tab | ++--------------+----------------------------------------------+ +| :const:`HT` | Alias for :const:`TAB`: "Horizontal tab" | ++--------------+----------------------------------------------+ +| :const:`LF` | Line feed | ++--------------+----------------------------------------------+ +| :const:`NL` | Alias for :const:`LF`: "New line" | ++--------------+----------------------------------------------+ +| :const:`VT` | Vertical tab | ++--------------+----------------------------------------------+ +| :const:`FF` | Form feed | ++--------------+----------------------------------------------+ +| :const:`CR` | Carriage return | ++--------------+----------------------------------------------+ +| :const:`SO` | Shift-out, begin alternate character set | ++--------------+----------------------------------------------+ +| :const:`SI` | Shift-in, resume default character set | ++--------------+----------------------------------------------+ +| :const:`DLE` | Data-link escape | ++--------------+----------------------------------------------+ +| :const:`DC1` | XON, for flow control | ++--------------+----------------------------------------------+ +| :const:`DC2` | Device control 2, block-mode flow control | ++--------------+----------------------------------------------+ +| :const:`DC3` | XOFF, for flow control | ++--------------+----------------------------------------------+ +| :const:`DC4` | Device control 4 | ++--------------+----------------------------------------------+ +| :const:`NAK` | Negative acknowledgement | ++--------------+----------------------------------------------+ +| :const:`SYN` | Synchronous idle | ++--------------+----------------------------------------------+ +| :const:`ETB` | End transmission block | ++--------------+----------------------------------------------+ +| :const:`CAN` | Cancel | ++--------------+----------------------------------------------+ +| :const:`EM` | End of medium | ++--------------+----------------------------------------------+ +| :const:`SUB` | Substitute | ++--------------+----------------------------------------------+ +| :const:`ESC` | Escape | ++--------------+----------------------------------------------+ +| :const:`FS` | File separator | ++--------------+----------------------------------------------+ +| :const:`GS` | Group separator | ++--------------+----------------------------------------------+ +| :const:`RS` | Record separator, block-mode terminator | ++--------------+----------------------------------------------+ +| :const:`US` | Unit separator | ++--------------+----------------------------------------------+ +| :const:`SP` | Space | ++--------------+----------------------------------------------+ +| :const:`DEL` | Delete | ++--------------+----------------------------------------------+ + +Note that many of these have little practical significance in modern usage. The +mnemonics derive from teleprinter conventions that predate digital computers. + +The module supplies the following functions, patterned on those in the standard +C library: + + +.. function:: isalnum(c) + + Checks for an ASCII alphanumeric character; it is equivalent to ``isalpha(c) or + isdigit(c)``. + + +.. function:: isalpha(c) + + Checks for an ASCII alphabetic character; it is equivalent to ``isupper(c) or + islower(c)``. + + +.. function:: isascii(c) + + Checks for a character value that fits in the 7-bit ASCII set. + + +.. function:: isblank(c) + + Checks for an ASCII whitespace character. + + +.. function:: iscntrl(c) + + Checks for an ASCII control character (in the range 0x00 to 0x1f). + + +.. function:: isdigit(c) + + Checks for an ASCII decimal digit, ``'0'`` through ``'9'``. This is equivalent + to ``c in string.digits``. + + +.. function:: isgraph(c) + + Checks for ASCII any printable character except space. + + +.. function:: islower(c) + + Checks for an ASCII lower-case character. + + +.. function:: isprint(c) + + Checks for any ASCII printable character including space. + + +.. function:: ispunct(c) + + Checks for any printable ASCII character which is not a space or an alphanumeric + character. + + +.. function:: isspace(c) + + Checks for ASCII white-space characters; space, line feed, carriage return, form + feed, horizontal tab, vertical tab. + + +.. function:: isupper(c) + + Checks for an ASCII uppercase letter. + + +.. function:: isxdigit(c) + + Checks for an ASCII hexadecimal digit. This is equivalent to ``c in + string.hexdigits``. + + +.. function:: isctrl(c) + + Checks for an ASCII control character (ordinal values 0 to 31). + + +.. function:: ismeta(c) + + Checks for a non-ASCII character (ordinal values 0x80 and above). + +These functions accept either integers or strings; when the argument is a +string, it is first converted using the built-in function :func:`ord`. + +Note that all these functions check ordinal bit values derived from the first +character of the string you pass in; they do not actually know anything about +the host machine's character encoding. For functions that know about the +character encoding (and handle internationalization properly) see the +:mod:`string` module. + +The following two functions take either a single-character string or integer +byte value; they return a value of the same type. + + +.. function:: ascii(c) + + Return the ASCII value corresponding to the low 7 bits of *c*. + + +.. function:: ctrl(c) + + Return the control character corresponding to the given character (the character + bit value is bitwise-anded with 0x1f). + + +.. function:: alt(c) + + Return the 8-bit character corresponding to the given ASCII character (the + character bit value is bitwise-ored with 0x80). + +The following function takes either a single-character string or integer value; +it returns a string. + + +.. function:: unctrl(c) + + Return a string representation of the ASCII character *c*. If *c* is printable, + this string is the character itself. If the character is a control character + (0x00-0x1f) the string consists of a caret (``'^'``) followed by the + corresponding uppercase letter. If the character is an ASCII delete (0x7f) the + string is ``'^?'``. If the character has its meta bit (0x80) set, the meta bit + is stripped, the preceding rules applied, and ``'!'`` prepended to the result. + + +.. data:: controlnames + + A 33-element string array that contains the ASCII mnemonics for the thirty-two + ASCII control characters from 0 (NUL) to 0x1f (US), in order, plus the mnemonic + ``SP`` for the space character. + diff --git a/Doc/library/curses.panel.rst b/Doc/library/curses.panel.rst new file mode 100644 index 0000000..59e5b86 --- /dev/null +++ b/Doc/library/curses.panel.rst @@ -0,0 +1,119 @@ + +:mod:`curses.panel` --- A panel stack extension for curses. +=========================================================== + +.. module:: curses.panel + :synopsis: A panel stack extension that adds depth to curses windows. +.. sectionauthor:: A.M. Kuchling + + +Panels are windows with the added feature of depth, so they can be stacked on +top of each other, and only the visible portions of each window will be +displayed. Panels can be added, moved up or down in the stack, and removed. + + +.. _cursespanel-functions: + +Functions +--------- + +The module :mod:`curses.panel` defines the following functions: + + +.. function:: bottom_panel() + + Returns the bottom panel in the panel stack. + + +.. function:: new_panel(win) + + Returns a panel object, associating it with the given window *win*. Be aware + that you need to keep the returned panel object referenced explicitly. If you + don't, the panel object is garbage collected and removed from the panel stack. + + +.. function:: top_panel() + + Returns the top panel in the panel stack. + + +.. function:: update_panels() + + Updates the virtual screen after changes in the panel stack. This does not call + :func:`curses.doupdate`, so you'll have to do this yourself. + + +.. _curses-panel-objects: + +Panel Objects +------------- + +Panel objects, as returned by :func:`new_panel` above, are windows with a +stacking order. There's always a window associated with a panel which determines +the content, while the panel methods are responsible for the window's depth in +the panel stack. + +Panel objects have the following methods: + + +.. method:: Panel.above() + + Returns the panel above the current panel. + + +.. method:: Panel.below() + + Returns the panel below the current panel. + + +.. method:: Panel.bottom() + + Push the panel to the bottom of the stack. + + +.. method:: Panel.hidden() + + Returns true if the panel is hidden (not visible), false otherwise. + + +.. method:: Panel.hide() + + Hide the panel. This does not delete the object, it just makes the window on + screen invisible. + + +.. method:: Panel.move(y, x) + + Move the panel to the screen coordinates ``(y, x)``. + + +.. method:: Panel.replace(win) + + Change the window associated with the panel to the window *win*. + + +.. method:: Panel.set_userptr(obj) + + Set the panel's user pointer to *obj*. This is used to associate an arbitrary + piece of data with the panel, and can be any Python object. + + +.. method:: Panel.show() + + Display the panel (which might have been hidden). + + +.. method:: Panel.top() + + Push panel to the top of the stack. + + +.. method:: Panel.userptr() + + Returns the user pointer for the panel. This might be any Python object. + + +.. method:: Panel.window() + + Returns the window object associated with the panel. + diff --git a/Doc/library/curses.rst b/Doc/library/curses.rst new file mode 100644 index 0000000..91af757 --- /dev/null +++ b/Doc/library/curses.rst @@ -0,0 +1,1679 @@ + +:mod:`curses` --- Terminal handling for character-cell displays +=============================================================== + +.. module:: curses + :synopsis: An interface to the curses library, providing portable terminal handling. +.. sectionauthor:: Moshe Zadka +.. sectionauthor:: Eric Raymond + + +.. versionchanged:: 1.6 + Added support for the ``ncurses`` library and converted to a package. + +The :mod:`curses` module provides an interface to the curses library, the +de-facto standard for portable advanced terminal handling. + +While curses is most widely used in the Unix environment, versions are available +for DOS, OS/2, and possibly other systems as well. This extension module is +designed to match the API of ncurses, an open-source curses library hosted on +Linux and the BSD variants of Unix. + + +.. seealso:: + + Module :mod:`curses.ascii` + Utilities for working with ASCII characters, regardless of your locale settings. + + Module :mod:`curses.panel` + A panel stack extension that adds depth to curses windows. + + Module :mod:`curses.textpad` + Editable text widget for curses supporting :program:`Emacs`\ -like bindings. + + Module :mod:`curses.wrapper` + Convenience function to ensure proper terminal setup and resetting on + application entry and exit. + + `Curses Programming with Python `_ + Tutorial material on using curses with Python, by Andrew Kuchling and Eric + Raymond, is available on the Python Web site. + + The :file:`Demo/curses/` directory in the Python source distribution contains + some example programs using the curses bindings provided by this module. + + +.. _curses-functions: + +Functions +--------- + +The module :mod:`curses` defines the following exception: + + +.. exception:: error + + Exception raised when a curses library function returns an error. + +.. note:: + + Whenever *x* or *y* arguments to a function or a method are optional, they + default to the current cursor location. Whenever *attr* is optional, it defaults + to :const:`A_NORMAL`. + +The module :mod:`curses` defines the following functions: + + +.. function:: baudrate() + + Returns the output speed of the terminal in bits per second. On software + terminal emulators it will have a fixed high value. Included for historical + reasons; in former times, it was used to write output loops for time delays and + occasionally to change interfaces depending on the line speed. + + +.. function:: beep() + + Emit a short attention sound. + + +.. function:: can_change_color() + + Returns true or false, depending on whether the programmer can change the colors + displayed by the terminal. + + +.. function:: cbreak() + + Enter cbreak mode. In cbreak mode (sometimes called "rare" mode) normal tty + line buffering is turned off and characters are available to be read one by one. + However, unlike raw mode, special characters (interrupt, quit, suspend, and flow + control) retain their effects on the tty driver and calling program. Calling + first :func:`raw` then :func:`cbreak` leaves the terminal in cbreak mode. + + +.. function:: color_content(color_number) + + Returns the intensity of the red, green, and blue (RGB) components in the color + *color_number*, which must be between ``0`` and :const:`COLORS`. A 3-tuple is + returned, containing the R,G,B values for the given color, which will be between + ``0`` (no component) and ``1000`` (maximum amount of component). + + +.. function:: color_pair(color_number) + + Returns the attribute value for displaying text in the specified color. This + attribute value can be combined with :const:`A_STANDOUT`, :const:`A_REVERSE`, + and the other :const:`A_\*` attributes. :func:`pair_number` is the counterpart + to this function. + + +.. function:: curs_set(visibility) + + Sets the cursor state. *visibility* can be set to 0, 1, or 2, for invisible, + normal, or very visible. If the terminal supports the visibility requested, the + previous cursor state is returned; otherwise, an exception is raised. On many + terminals, the "visible" mode is an underline cursor and the "very visible" mode + is a block cursor. + + +.. function:: def_prog_mode() + + Saves the current terminal mode as the "program" mode, the mode when the running + program is using curses. (Its counterpart is the "shell" mode, for when the + program is not in curses.) Subsequent calls to :func:`reset_prog_mode` will + restore this mode. + + +.. function:: def_shell_mode() + + Saves the current terminal mode as the "shell" mode, the mode when the running + program is not using curses. (Its counterpart is the "program" mode, when the + program is using curses capabilities.) Subsequent calls to + :func:`reset_shell_mode` will restore this mode. + + +.. function:: delay_output(ms) + + Inserts an *ms* millisecond pause in output. + + +.. function:: doupdate() + + Update the physical screen. The curses library keeps two data structures, one + representing the current physical screen contents and a virtual screen + representing the desired next state. The :func:`doupdate` ground updates the + physical screen to match the virtual screen. + + The virtual screen may be updated by a :meth:`noutrefresh` call after write + operations such as :meth:`addstr` have been performed on a window. The normal + :meth:`refresh` call is simply :meth:`noutrefresh` followed by :func:`doupdate`; + if you have to update multiple windows, you can speed performance and perhaps + reduce screen flicker by issuing :meth:`noutrefresh` calls on all windows, + followed by a single :func:`doupdate`. + + +.. function:: echo() + + Enter echo mode. In echo mode, each character input is echoed to the screen as + it is entered. + + +.. function:: endwin() + + De-initialize the library, and return terminal to normal status. + + +.. function:: erasechar() + + Returns the user's current erase character. Under Unix operating systems this + is a property of the controlling tty of the curses program, and is not set by + the curses library itself. + + +.. function:: filter() + + The :func:`filter` routine, if used, must be called before :func:`initscr` is + called. The effect is that, during those calls, LINES is set to 1; the + capabilities clear, cup, cud, cud1, cuu1, cuu, vpa are disabled; and the home + string is set to the value of cr. The effect is that the cursor is confined to + the current line, and so are screen updates. This may be used for enabling + character-at-a-time line editing without touching the rest of the screen. + + +.. function:: flash() + + Flash the screen. That is, change it to reverse-video and then change it back + in a short interval. Some people prefer such as 'visible bell' to the audible + attention signal produced by :func:`beep`. + + +.. function:: flushinp() + + Flush all input buffers. This throws away any typeahead that has been typed + by the user and has not yet been processed by the program. + + +.. function:: getmouse() + + After :meth:`getch` returns :const:`KEY_MOUSE` to signal a mouse event, this + method should be call to retrieve the queued mouse event, represented as a + 5-tuple ``(id, x, y, z, bstate)``. *id* is an ID value used to distinguish + multiple devices, and *x*, *y*, *z* are the event's coordinates. (*z* is + currently unused.). *bstate* is an integer value whose bits will be set to + indicate the type of event, and will be the bitwise OR of one or more of the + following constants, where *n* is the button number from 1 to 4: + :const:`BUTTONn_PRESSED`, :const:`BUTTONn_RELEASED`, :const:`BUTTONn_CLICKED`, + :const:`BUTTONn_DOUBLE_CLICKED`, :const:`BUTTONn_TRIPLE_CLICKED`, + :const:`BUTTON_SHIFT`, :const:`BUTTON_CTRL`, :const:`BUTTON_ALT`. + + +.. function:: getsyx() + + Returns the current coordinates of the virtual screen cursor in y and x. If + leaveok is currently true, then -1,-1 is returned. + + +.. function:: getwin(file) + + Reads window related data stored in the file by an earlier :func:`putwin` call. + The routine then creates and initializes a new window using that data, returning + the new window object. + + +.. function:: has_colors() + + Returns true if the terminal can display colors; otherwise, it returns false. + + +.. function:: has_ic() + + Returns true if the terminal has insert- and delete- character capabilities. + This function is included for historical reasons only, as all modern software + terminal emulators have such capabilities. + + +.. function:: has_il() + + Returns true if the terminal has insert- and delete-line capabilities, or can + simulate them using scrolling regions. This function is included for + historical reasons only, as all modern software terminal emulators have such + capabilities. + + +.. function:: has_key(ch) + + Takes a key value *ch*, and returns true if the current terminal type recognizes + a key with that value. + + +.. function:: halfdelay(tenths) + + Used for half-delay mode, which is similar to cbreak mode in that characters + typed by the user are immediately available to the program. However, after + blocking for *tenths* tenths of seconds, an exception is raised if nothing has + been typed. The value of *tenths* must be a number between 1 and 255. Use + :func:`nocbreak` to leave half-delay mode. + + +.. function:: init_color(color_number, r, g, b) + + Changes the definition of a color, taking the number of the color to be changed + followed by three RGB values (for the amounts of red, green, and blue + components). The value of *color_number* must be between ``0`` and + :const:`COLORS`. Each of *r*, *g*, *b*, must be a value between ``0`` and + ``1000``. When :func:`init_color` is used, all occurrences of that color on the + screen immediately change to the new definition. This function is a no-op on + most terminals; it is active only if :func:`can_change_color` returns ``1``. + + +.. function:: init_pair(pair_number, fg, bg) + + Changes the definition of a color-pair. It takes three arguments: the number of + the color-pair to be changed, the foreground color number, and the background + color number. The value of *pair_number* must be between ``1`` and + ``COLOR_PAIRS - 1`` (the ``0`` color pair is wired to white on black and cannot + be changed). The value of *fg* and *bg* arguments must be between ``0`` and + :const:`COLORS`. If the color-pair was previously initialized, the screen is + refreshed and all occurrences of that color-pair are changed to the new + definition. + + +.. function:: initscr() + + Initialize the library. Returns a :class:`WindowObject` which represents the + whole screen. + + .. note:: + + If there is an error opening the terminal, the underlying curses library may + cause the interpreter to exit. + + +.. function:: isendwin() + + Returns true if :func:`endwin` has been called (that is, the curses library has + been deinitialized). + + +.. function:: keyname(k) + + Return the name of the key numbered *k*. The name of a key generating printable + ASCII character is the key's character. The name of a control-key combination + is a two-character string consisting of a caret followed by the corresponding + printable ASCII character. The name of an alt-key combination (128-255) is a + string consisting of the prefix 'M-' followed by the name of the corresponding + ASCII character. + + +.. function:: killchar() + + Returns the user's current line kill character. Under Unix operating systems + this is a property of the controlling tty of the curses program, and is not set + by the curses library itself. + + +.. function:: longname() + + Returns a string containing the terminfo long name field describing the current + terminal. The maximum length of a verbose description is 128 characters. It is + defined only after the call to :func:`initscr`. + + +.. function:: meta(yes) + + If *yes* is 1, allow 8-bit characters to be input. If *yes* is 0, allow only + 7-bit chars. + + +.. function:: mouseinterval(interval) + + Sets the maximum time in milliseconds that can elapse between press and release + events in order for them to be recognized as a click, and returns the previous + interval value. The default value is 200 msec, or one fifth of a second. + + +.. function:: mousemask(mousemask) + + Sets the mouse events to be reported, and returns a tuple ``(availmask, + oldmask)``. *availmask* indicates which of the specified mouse events can be + reported; on complete failure it returns 0. *oldmask* is the previous value of + the given window's mouse event mask. If this function is never called, no mouse + events are ever reported. + + +.. function:: napms(ms) + + Sleep for *ms* milliseconds. + + +.. function:: newpad(nlines, ncols) + + Creates and returns a pointer to a new pad data structure with the given number + of lines and columns. A pad is returned as a window object. + + A pad is like a window, except that it is not restricted by the screen size, and + is not necessarily associated with a particular part of the screen. Pads can be + used when a large window is needed, and only a part of the window will be on the + screen at one time. Automatic refreshes of pads (such as from scrolling or + echoing of input) do not occur. The :meth:`refresh` and :meth:`noutrefresh` + methods of a pad require 6 arguments to specify the part of the pad to be + displayed and the location on the screen to be used for the display. The + arguments are pminrow, pmincol, sminrow, smincol, smaxrow, smaxcol; the p + arguments refer to the upper left corner of the pad region to be displayed and + the s arguments define a clipping box on the screen within which the pad region + is to be displayed. + + +.. function:: newwin([nlines, ncols,] begin_y, begin_x) + + Return a new window, whose left-upper corner is at ``(begin_y, begin_x)``, and + whose height/width is *nlines*/*ncols*. + + By default, the window will extend from the specified position to the lower + right corner of the screen. + + +.. function:: nl() + + Enter newline mode. This mode translates the return key into newline on input, + and translates newline into return and line-feed on output. Newline mode is + initially on. + + +.. function:: nocbreak() + + Leave cbreak mode. Return to normal "cooked" mode with line buffering. + + +.. function:: noecho() + + Leave echo mode. Echoing of input characters is turned off. + + +.. function:: nonl() + + Leave newline mode. Disable translation of return into newline on input, and + disable low-level translation of newline into newline/return on output (but this + does not change the behavior of ``addch('\n')``, which always does the + equivalent of return and line feed on the virtual screen). With translation + off, curses can sometimes speed up vertical motion a little; also, it will be + able to detect the return key on input. + + +.. function:: noqiflush() + + When the noqiflush routine is used, normal flush of input and output queues + associated with the INTR, QUIT and SUSP characters will not be done. You may + want to call :func:`noqiflush` in a signal handler if you want output to + continue as though the interrupt had not occurred, after the handler exits. + + +.. function:: noraw() + + Leave raw mode. Return to normal "cooked" mode with line buffering. + + +.. function:: pair_content(pair_number) + + Returns a tuple ``(fg, bg)`` containing the colors for the requested color pair. + The value of *pair_number* must be between ``1`` and ``COLOR_PAIRS - 1``. + + +.. function:: pair_number(attr) + + Returns the number of the color-pair set by the attribute value *attr*. + :func:`color_pair` is the counterpart to this function. + + +.. function:: putp(string) + + Equivalent to ``tputs(str, 1, putchar)``; emits the value of a specified + terminfo capability for the current terminal. Note that the output of putp + always goes to standard output. + + +.. function:: qiflush( [flag] ) + + If *flag* is false, the effect is the same as calling :func:`noqiflush`. If + *flag* is true, or no argument is provided, the queues will be flushed when + these control characters are read. + + +.. function:: raw() + + Enter raw mode. In raw mode, normal line buffering and processing of + interrupt, quit, suspend, and flow control keys are turned off; characters are + presented to curses input functions one by one. + + +.. function:: reset_prog_mode() + + Restores the terminal to "program" mode, as previously saved by + :func:`def_prog_mode`. + + +.. function:: reset_shell_mode() + + Restores the terminal to "shell" mode, as previously saved by + :func:`def_shell_mode`. + + +.. function:: setsyx(y, x) + + Sets the virtual screen cursor to *y*, *x*. If *y* and *x* are both -1, then + leaveok is set. + + +.. function:: setupterm([termstr, fd]) + + Initializes the terminal. *termstr* is a string giving the terminal name; if + omitted, the value of the TERM environment variable will be used. *fd* is the + file descriptor to which any initialization sequences will be sent; if not + supplied, the file descriptor for ``sys.stdout`` will be used. + + +.. function:: start_color() + + Must be called if the programmer wants to use colors, and before any other color + manipulation routine is called. It is good practice to call this routine right + after :func:`initscr`. + + :func:`start_color` initializes eight basic colors (black, red, green, yellow, + blue, magenta, cyan, and white), and two global variables in the :mod:`curses` + module, :const:`COLORS` and :const:`COLOR_PAIRS`, containing the maximum number + of colors and color-pairs the terminal can support. It also restores the colors + on the terminal to the values they had when the terminal was just turned on. + + +.. function:: termattrs() + + Returns a logical OR of all video attributes supported by the terminal. This + information is useful when a curses program needs complete control over the + appearance of the screen. + + +.. function:: termname() + + Returns the value of the environment variable TERM, truncated to 14 characters. + + +.. function:: tigetflag(capname) + + Returns the value of the Boolean capability corresponding to the terminfo + capability name *capname*. The value ``-1`` is returned if *capname* is not a + Boolean capability, or ``0`` if it is canceled or absent from the terminal + description. + + +.. function:: tigetnum(capname) + + Returns the value of the numeric capability corresponding to the terminfo + capability name *capname*. The value ``-2`` is returned if *capname* is not a + numeric capability, or ``-1`` if it is canceled or absent from the terminal + description. + + +.. function:: tigetstr(capname) + + Returns the value of the string capability corresponding to the terminfo + capability name *capname*. ``None`` is returned if *capname* is not a string + capability, or is canceled or absent from the terminal description. + + +.. function:: tparm(str[,...]) + + Instantiates the string *str* with the supplied parameters, where *str* should + be a parameterized string obtained from the terminfo database. E.g. + ``tparm(tigetstr("cup"), 5, 3)`` could result in ``'\033[6;4H'``, the exact + result depending on terminal type. + + +.. function:: typeahead(fd) + + Specifies that the file descriptor *fd* be used for typeahead checking. If *fd* + is ``-1``, then no typeahead checking is done. + + The curses library does "line-breakout optimization" by looking for typeahead + periodically while updating the screen. If input is found, and it is coming + from a tty, the current update is postponed until refresh or doupdate is called + again, allowing faster response to commands typed in advance. This function + allows specifying a different file descriptor for typeahead checking. + + +.. function:: unctrl(ch) + + Returns a string which is a printable representation of the character *ch*. + Control characters are displayed as a caret followed by the character, for + example as ``^C``. Printing characters are left as they are. + + +.. function:: ungetch(ch) + + Push *ch* so the next :meth:`getch` will return it. + + .. note:: + + Only one *ch* can be pushed before :meth:`getch` is called. + + +.. function:: ungetmouse(id, x, y, z, bstate) + + Push a :const:`KEY_MOUSE` event onto the input queue, associating the given + state data with it. + + +.. function:: use_env(flag) + + If used, this function should be called before :func:`initscr` or newterm are + called. When *flag* is false, the values of lines and columns specified in the + terminfo database will be used, even if environment variables :envvar:`LINES` + and :envvar:`COLUMNS` (used by default) are set, or if curses is running in a + window (in which case default behavior would be to use the window size if + :envvar:`LINES` and :envvar:`COLUMNS` are not set). + + +.. function:: use_default_colors() + + Allow use of default values for colors on terminals supporting this feature. Use + this to support transparency in your application. The default color is assigned + to the color number -1. After calling this function, ``init_pair(x, + curses.COLOR_RED, -1)`` initializes, for instance, color pair *x* to a red + foreground color on the default background. + + +.. _curses-window-objects: + +Window Objects +-------------- + +Window objects, as returned by :func:`initscr` and :func:`newwin` above, have +the following methods: + + +.. method:: window.addch([y, x,] ch[, attr]) + + .. note:: + + A *character* means a C character (an ASCII code), rather then a Python + character (a string of length 1). (This note is true whenever the documentation + mentions a character.) The builtin :func:`ord` is handy for conveying strings to + codes. + + Paint character *ch* at ``(y, x)`` with attributes *attr*, overwriting any + character previously painter at that location. By default, the character + position and attributes are the current settings for the window object. + + +.. method:: window.addnstr([y, x,] str, n[, attr]) + + Paint at most *n* characters of the string *str* at ``(y, x)`` with attributes + *attr*, overwriting anything previously on the display. + + +.. method:: window.addstr([y, x,] str[, attr]) + + Paint the string *str* at ``(y, x)`` with attributes *attr*, overwriting + anything previously on the display. + + +.. method:: window.attroff(attr) + + Remove attribute *attr* from the "background" set applied to all writes to the + current window. + + +.. method:: window.attron(attr) + + Add attribute *attr* from the "background" set applied to all writes to the + current window. + + +.. method:: window.attrset(attr) + + Set the "background" set of attributes to *attr*. This set is initially 0 (no + attributes). + + +.. method:: window.bkgd(ch[, attr]) + + Sets the background property of the window to the character *ch*, with + attributes *attr*. The change is then applied to every character position in + that window: + + * The attribute of every character in the window is changed to the new + background attribute. + + * Wherever the former background character appears, it is changed to the new + background character. + + +.. method:: window.bkgdset(ch[, attr]) + + Sets the window's background. A window's background consists of a character and + any combination of attributes. The attribute part of the background is combined + (OR'ed) with all non-blank characters that are written into the window. Both + the character and attribute parts of the background are combined with the blank + characters. The background becomes a property of the character and moves with + the character through any scrolling and insert/delete line/character operations. + + +.. method:: window.border([ls[, rs[, ts[, bs[, tl[, tr[, bl[, br]]]]]]]]) + + Draw a border around the edges of the window. Each parameter specifies the + character to use for a specific part of the border; see the table below for more + details. The characters can be specified as integers or as one-character + strings. + + .. note:: + + A ``0`` value for any parameter will cause the default character to be used for + that parameter. Keyword parameters can *not* be used. The defaults are listed + in this table: + + +-----------+---------------------+-----------------------+ + | Parameter | Description | Default value | + +===========+=====================+=======================+ + | *ls* | Left side | :const:`ACS_VLINE` | + +-----------+---------------------+-----------------------+ + | *rs* | Right side | :const:`ACS_VLINE` | + +-----------+---------------------+-----------------------+ + | *ts* | Top | :const:`ACS_HLINE` | + +-----------+---------------------+-----------------------+ + | *bs* | Bottom | :const:`ACS_HLINE` | + +-----------+---------------------+-----------------------+ + | *tl* | Upper-left corner | :const:`ACS_ULCORNER` | + +-----------+---------------------+-----------------------+ + | *tr* | Upper-right corner | :const:`ACS_URCORNER` | + +-----------+---------------------+-----------------------+ + | *bl* | Bottom-left corner | :const:`ACS_LLCORNER` | + +-----------+---------------------+-----------------------+ + | *br* | Bottom-right corner | :const:`ACS_LRCORNER` | + +-----------+---------------------+-----------------------+ + + +.. method:: window.box([vertch, horch]) + + Similar to :meth:`border`, but both *ls* and *rs* are *vertch* and both *ts* and + bs are *horch*. The default corner characters are always used by this function. + + +.. method:: window.chgat([y, x, ] [num,] attr) + + Sets the attributes of *num* characters at the current cursor position, or at + position ``(y, x)`` if supplied. If no value of *num* is given or *num* = -1, + the attribute will be set on all the characters to the end of the line. This + function does not move the cursor. The changed line will be touched using the + :meth:`touchline` method so that the contents will be redisplayed by the next + window refresh. + + +.. method:: window.clear() + + Like :meth:`erase`, but also causes the whole window to be repainted upon next + call to :meth:`refresh`. + + +.. method:: window.clearok(yes) + + If *yes* is 1, the next call to :meth:`refresh` will clear the window + completely. + + +.. method:: window.clrtobot() + + Erase from cursor to the end of the window: all lines below the cursor are + deleted, and then the equivalent of :meth:`clrtoeol` is performed. + + +.. method:: window.clrtoeol() + + Erase from cursor to the end of the line. + + +.. method:: window.cursyncup() + + Updates the current cursor position of all the ancestors of the window to + reflect the current cursor position of the window. + + +.. method:: window.delch([y, x]) + + Delete any character at ``(y, x)``. + + +.. method:: window.deleteln() + + Delete the line under the cursor. All following lines are moved up by 1 line. + + +.. method:: window.derwin([nlines, ncols,] begin_y, begin_x) + + An abbreviation for "derive window", :meth:`derwin` is the same as calling + :meth:`subwin`, except that *begin_y* and *begin_x* are relative to the origin + of the window, rather than relative to the entire screen. Returns a window + object for the derived window. + + +.. method:: window.echochar(ch[, attr]) + + Add character *ch* with attribute *attr*, and immediately call :meth:`refresh` + on the window. + + +.. method:: window.enclose(y, x) + + Tests whether the given pair of screen-relative character-cell coordinates are + enclosed by the given window, returning true or false. It is useful for + determining what subset of the screen windows enclose the location of a mouse + event. + + +.. method:: window.erase() + + Clear the window. + + +.. method:: window.getbegyx() + + Return a tuple ``(y, x)`` of co-ordinates of upper-left corner. + + +.. method:: window.getch([y, x]) + + Get a character. Note that the integer returned does *not* have to be in ASCII + range: function keys, keypad keys and so on return numbers higher than 256. In + no-delay mode, -1 is returned if there is no input. + + +.. method:: window.getkey([y, x]) + + Get a character, returning a string instead of an integer, as :meth:`getch` + does. Function keys, keypad keys and so on return a multibyte string containing + the key name. In no-delay mode, an exception is raised if there is no input. + + +.. method:: window.getmaxyx() + + Return a tuple ``(y, x)`` of the height and width of the window. + + +.. method:: window.getparyx() + + Returns the beginning coordinates of this window relative to its parent window + into two integer variables y and x. Returns ``-1,-1`` if this window has no + parent. + + +.. method:: window.getstr([y, x]) + + Read a string from the user, with primitive line editing capacity. + + +.. method:: window.getyx() + + Return a tuple ``(y, x)`` of current cursor position relative to the window's + upper-left corner. + + +.. method:: window.hline([y, x,] ch, n) + + Display a horizontal line starting at ``(y, x)`` with length *n* consisting of + the character *ch*. + + +.. method:: window.idcok(flag) + + If *flag* is false, curses no longer considers using the hardware insert/delete + character feature of the terminal; if *flag* is true, use of character insertion + and deletion is enabled. When curses is first initialized, use of character + insert/delete is enabled by default. + + +.. method:: window.idlok(yes) + + If called with *yes* equal to 1, :mod:`curses` will try and use hardware line + editing facilities. Otherwise, line insertion/deletion are disabled. + + +.. method:: window.immedok(flag) + + If *flag* is true, any change in the window image automatically causes the + window to be refreshed; you no longer have to call :meth:`refresh` yourself. + However, it may degrade performance considerably, due to repeated calls to + wrefresh. This option is disabled by default. + + +.. method:: window.inch([y, x]) + + Return the character at the given position in the window. The bottom 8 bits are + the character proper, and upper bits are the attributes. + + +.. method:: window.insch([y, x,] ch[, attr]) + + Paint character *ch* at ``(y, x)`` with attributes *attr*, moving the line from + position *x* right by one character. + + +.. method:: window.insdelln(nlines) + + Inserts *nlines* lines into the specified window above the current line. The + *nlines* bottom lines are lost. For negative *nlines*, delete *nlines* lines + starting with the one under the cursor, and move the remaining lines up. The + bottom *nlines* lines are cleared. The current cursor position remains the + same. + + +.. method:: window.insertln() + + Insert a blank line under the cursor. All following lines are moved down by 1 + line. + + +.. method:: window.insnstr([y, x,] str, n [, attr]) + + Insert a character string (as many characters as will fit on the line) before + the character under the cursor, up to *n* characters. If *n* is zero or + negative, the entire string is inserted. All characters to the right of the + cursor are shifted right, with the rightmost characters on the line being lost. + The cursor position does not change (after moving to *y*, *x*, if specified). + + +.. method:: window.insstr([y, x, ] str [, attr]) + + Insert a character string (as many characters as will fit on the line) before + the character under the cursor. All characters to the right of the cursor are + shifted right, with the rightmost characters on the line being lost. The cursor + position does not change (after moving to *y*, *x*, if specified). + + +.. method:: window.instr([y, x] [, n]) + + Returns a string of characters, extracted from the window starting at the + current cursor position, or at *y*, *x* if specified. Attributes are stripped + from the characters. If *n* is specified, :meth:`instr` returns return a string + at most *n* characters long (exclusive of the trailing NUL). + + +.. method:: window.is_linetouched(line) + + Returns true if the specified line was modified since the last call to + :meth:`refresh`; otherwise returns false. Raises a :exc:`curses.error` + exception if *line* is not valid for the given window. + + +.. method:: window.is_wintouched() + + Returns true if the specified window was modified since the last call to + :meth:`refresh`; otherwise returns false. + + +.. method:: window.keypad(yes) + + If *yes* is 1, escape sequences generated by some keys (keypad, function keys) + will be interpreted by :mod:`curses`. If *yes* is 0, escape sequences will be + left as is in the input stream. + + +.. method:: window.leaveok(yes) + + If *yes* is 1, cursor is left where it is on update, instead of being at "cursor + position." This reduces cursor movement where possible. If possible the cursor + will be made invisible. + + If *yes* is 0, cursor will always be at "cursor position" after an update. + + +.. method:: window.move(new_y, new_x) + + Move cursor to ``(new_y, new_x)``. + + +.. method:: window.mvderwin(y, x) + + Moves the window inside its parent window. The screen-relative parameters of + the window are not changed. This routine is used to display different parts of + the parent window at the same physical position on the screen. + + +.. method:: window.mvwin(new_y, new_x) + + Move the window so its upper-left corner is at ``(new_y, new_x)``. + + +.. method:: window.nodelay(yes) + + If *yes* is ``1``, :meth:`getch` will be non-blocking. + + +.. method:: window.notimeout(yes) + + If *yes* is ``1``, escape sequences will not be timed out. + + If *yes* is ``0``, after a few milliseconds, an escape sequence will not be + interpreted, and will be left in the input stream as is. + + +.. method:: window.noutrefresh() + + Mark for refresh but wait. This function updates the data structure + representing the desired state of the window, but does not force an update of + the physical screen. To accomplish that, call :func:`doupdate`. + + +.. method:: window.overlay(destwin[, sminrow, smincol, dminrow, dmincol, dmaxrow, dmaxcol]) + + Overlay the window on top of *destwin*. The windows need not be the same size, + only the overlapping region is copied. This copy is non-destructive, which means + that the current background character does not overwrite the old contents of + *destwin*. + + To get fine-grained control over the copied region, the second form of + :meth:`overlay` can be used. *sminrow* and *smincol* are the upper-left + coordinates of the source window, and the other variables mark a rectangle in + the destination window. + + +.. method:: window.overwrite(destwin[, sminrow, smincol, dminrow, dmincol, dmaxrow, dmaxcol]) + + Overwrite the window on top of *destwin*. The windows need not be the same size, + in which case only the overlapping region is copied. This copy is destructive, + which means that the current background character overwrites the old contents of + *destwin*. + + To get fine-grained control over the copied region, the second form of + :meth:`overwrite` can be used. *sminrow* and *smincol* are the upper-left + coordinates of the source window, the other variables mark a rectangle in the + destination window. + + +.. method:: window.putwin(file) + + Writes all data associated with the window into the provided file object. This + information can be later retrieved using the :func:`getwin` function. + + +.. method:: window.redrawln(beg, num) + + Indicates that the *num* screen lines, starting at line *beg*, are corrupted and + should be completely redrawn on the next :meth:`refresh` call. + + +.. method:: window.redrawwin() + + Touches the entire window, causing it to be completely redrawn on the next + :meth:`refresh` call. + + +.. method:: window.refresh([pminrow, pmincol, sminrow, smincol, smaxrow, smaxcol]) + + Update the display immediately (sync actual screen with previous + drawing/deleting methods). + + The 6 optional arguments can only be specified when the window is a pad created + with :func:`newpad`. The additional parameters are needed to indicate what part + of the pad and screen are involved. *pminrow* and *pmincol* specify the upper + left-hand corner of the rectangle to be displayed in the pad. *sminrow*, + *smincol*, *smaxrow*, and *smaxcol* specify the edges of the rectangle to be + displayed on the screen. The lower right-hand corner of the rectangle to be + displayed in the pad is calculated from the screen coordinates, since the + rectangles must be the same size. Both rectangles must be entirely contained + within their respective structures. Negative values of *pminrow*, *pmincol*, + *sminrow*, or *smincol* are treated as if they were zero. + + +.. method:: window.scroll([lines=1]) + + Scroll the screen or scrolling region upward by *lines* lines. + + +.. method:: window.scrollok(flag) + + Controls what happens when the cursor of a window is moved off the edge of the + window or scrolling region, either as a result of a newline action on the bottom + line, or typing the last character of the last line. If *flag* is false, the + cursor is left on the bottom line. If *flag* is true, the window is scrolled up + one line. Note that in order to get the physical scrolling effect on the + terminal, it is also necessary to call :meth:`idlok`. + + +.. method:: window.setscrreg(top, bottom) + + Set the scrolling region from line *top* to line *bottom*. All scrolling actions + will take place in this region. + + +.. method:: window.standend() + + Turn off the standout attribute. On some terminals this has the side effect of + turning off all attributes. + + +.. method:: window.standout() + + Turn on attribute *A_STANDOUT*. + + +.. method:: window.subpad([nlines, ncols,] begin_y, begin_x) + + Return a sub-window, whose upper-left corner is at ``(begin_y, begin_x)``, and + whose width/height is *ncols*/*nlines*. + + +.. method:: window.subwin([nlines, ncols,] begin_y, begin_x) + + Return a sub-window, whose upper-left corner is at ``(begin_y, begin_x)``, and + whose width/height is *ncols*/*nlines*. + + By default, the sub-window will extend from the specified position to the lower + right corner of the window. + + +.. method:: window.syncdown() + + Touches each location in the window that has been touched in any of its ancestor + windows. This routine is called by :meth:`refresh`, so it should almost never + be necessary to call it manually. + + +.. method:: window.syncok(flag) + + If called with *flag* set to true, then :meth:`syncup` is called automatically + whenever there is a change in the window. + + +.. method:: window.syncup() + + Touches all locations in ancestors of the window that have been changed in the + window. + + +.. method:: window.timeout(delay) + + Sets blocking or non-blocking read behavior for the window. If *delay* is + negative, blocking read is used (which will wait indefinitely for input). If + *delay* is zero, then non-blocking read is used, and -1 will be returned by + :meth:`getch` if no input is waiting. If *delay* is positive, then + :meth:`getch` will block for *delay* milliseconds, and return -1 if there is + still no input at the end of that time. + + +.. method:: window.touchline(start, count[, changed]) + + Pretend *count* lines have been changed, starting with line *start*. If + *changed* is supplied, it specifies whether the affected lines are marked as + having been changed (*changed*\ =1) or unchanged (*changed*\ =0). + + +.. method:: window.touchwin() + + Pretend the whole window has been changed, for purposes of drawing + optimizations. + + +.. method:: window.untouchwin() + + Marks all lines in the window as unchanged since the last call to + :meth:`refresh`. + + +.. method:: window.vline([y, x,] ch, n) + + Display a vertical line starting at ``(y, x)`` with length *n* consisting of the + character *ch*. + + +Constants +--------- + +The :mod:`curses` module defines the following data members: + + +.. data:: ERR + + Some curses routines that return an integer, such as :func:`getch`, return + :const:`ERR` upon failure. + + +.. data:: OK + + Some curses routines that return an integer, such as :func:`napms`, return + :const:`OK` upon success. + + +.. data:: version + + A string representing the current version of the module. Also available as + :const:`__version__`. + +Several constants are available to specify character cell attributes: + ++------------------+-------------------------------+ +| Attribute | Meaning | ++==================+===============================+ +| ``A_ALTCHARSET`` | Alternate character set mode. | ++------------------+-------------------------------+ +| ``A_BLINK`` | Blink mode. | ++------------------+-------------------------------+ +| ``A_BOLD`` | Bold mode. | ++------------------+-------------------------------+ +| ``A_DIM`` | Dim mode. | ++------------------+-------------------------------+ +| ``A_NORMAL`` | Normal attribute. | ++------------------+-------------------------------+ +| ``A_STANDOUT`` | Standout mode. | ++------------------+-------------------------------+ +| ``A_UNDERLINE`` | Underline mode. | ++------------------+-------------------------------+ + +Keys are referred to by integer constants with names starting with ``KEY_``. +The exact keycaps available are system dependent. + +.. % XXX this table is far too large! +.. % XXX should this table be alphabetized? + ++-------------------+--------------------------------------------+ +| Key constant | Key | ++===================+============================================+ +| ``KEY_MIN`` | Minimum key value | ++-------------------+--------------------------------------------+ +| ``KEY_BREAK`` | Break key (unreliable) | ++-------------------+--------------------------------------------+ +| ``KEY_DOWN`` | Down-arrow | ++-------------------+--------------------------------------------+ +| ``KEY_UP`` | Up-arrow | ++-------------------+--------------------------------------------+ +| ``KEY_LEFT`` | Left-arrow | ++-------------------+--------------------------------------------+ +| ``KEY_RIGHT`` | Right-arrow | ++-------------------+--------------------------------------------+ +| ``KEY_HOME`` | Home key (upward+left arrow) | ++-------------------+--------------------------------------------+ +| ``KEY_BACKSPACE`` | Backspace (unreliable) | ++-------------------+--------------------------------------------+ +| ``KEY_F0`` | Function keys. Up to 64 function keys are | +| | supported. | ++-------------------+--------------------------------------------+ +| ``KEY_Fn`` | Value of function key *n* | ++-------------------+--------------------------------------------+ +| ``KEY_DL`` | Delete line | ++-------------------+--------------------------------------------+ +| ``KEY_IL`` | Insert line | ++-------------------+--------------------------------------------+ +| ``KEY_DC`` | Delete character | ++-------------------+--------------------------------------------+ +| ``KEY_IC`` | Insert char or enter insert mode | ++-------------------+--------------------------------------------+ +| ``KEY_EIC`` | Exit insert char mode | ++-------------------+--------------------------------------------+ +| ``KEY_CLEAR`` | Clear screen | ++-------------------+--------------------------------------------+ +| ``KEY_EOS`` | Clear to end of screen | ++-------------------+--------------------------------------------+ +| ``KEY_EOL`` | Clear to end of line | ++-------------------+--------------------------------------------+ +| ``KEY_SF`` | Scroll 1 line forward | ++-------------------+--------------------------------------------+ +| ``KEY_SR`` | Scroll 1 line backward (reverse) | ++-------------------+--------------------------------------------+ +| ``KEY_NPAGE`` | Next page | ++-------------------+--------------------------------------------+ +| ``KEY_PPAGE`` | Previous page | ++-------------------+--------------------------------------------+ +| ``KEY_STAB`` | Set tab | ++-------------------+--------------------------------------------+ +| ``KEY_CTAB`` | Clear tab | ++-------------------+--------------------------------------------+ +| ``KEY_CATAB`` | Clear all tabs | ++-------------------+--------------------------------------------+ +| ``KEY_ENTER`` | Enter or send (unreliable) | ++-------------------+--------------------------------------------+ +| ``KEY_SRESET`` | Soft (partial) reset (unreliable) | ++-------------------+--------------------------------------------+ +| ``KEY_RESET`` | Reset or hard reset (unreliable) | ++-------------------+--------------------------------------------+ +| ``KEY_PRINT`` | Print | ++-------------------+--------------------------------------------+ +| ``KEY_LL`` | Home down or bottom (lower left) | ++-------------------+--------------------------------------------+ +| ``KEY_A1`` | Upper left of keypad | ++-------------------+--------------------------------------------+ +| ``KEY_A3`` | Upper right of keypad | ++-------------------+--------------------------------------------+ +| ``KEY_B2`` | Center of keypad | ++-------------------+--------------------------------------------+ +| ``KEY_C1`` | Lower left of keypad | ++-------------------+--------------------------------------------+ +| ``KEY_C3`` | Lower right of keypad | ++-------------------+--------------------------------------------+ +| ``KEY_BTAB`` | Back tab | ++-------------------+--------------------------------------------+ +| ``KEY_BEG`` | Beg (beginning) | ++-------------------+--------------------------------------------+ +| ``KEY_CANCEL`` | Cancel | ++-------------------+--------------------------------------------+ +| ``KEY_CLOSE`` | Close | ++-------------------+--------------------------------------------+ +| ``KEY_COMMAND`` | Cmd (command) | ++-------------------+--------------------------------------------+ +| ``KEY_COPY`` | Copy | ++-------------------+--------------------------------------------+ +| ``KEY_CREATE`` | Create | ++-------------------+--------------------------------------------+ +| ``KEY_END`` | End | ++-------------------+--------------------------------------------+ +| ``KEY_EXIT`` | Exit | ++-------------------+--------------------------------------------+ +| ``KEY_FIND`` | Find | ++-------------------+--------------------------------------------+ +| ``KEY_HELP`` | Help | ++-------------------+--------------------------------------------+ +| ``KEY_MARK`` | Mark | ++-------------------+--------------------------------------------+ +| ``KEY_MESSAGE`` | Message | ++-------------------+--------------------------------------------+ +| ``KEY_MOVE`` | Move | ++-------------------+--------------------------------------------+ +| ``KEY_NEXT`` | Next | ++-------------------+--------------------------------------------+ +| ``KEY_OPEN`` | Open | ++-------------------+--------------------------------------------+ +| ``KEY_OPTIONS`` | Options | ++-------------------+--------------------------------------------+ +| ``KEY_PREVIOUS`` | Prev (previous) | ++-------------------+--------------------------------------------+ +| ``KEY_REDO`` | Redo | ++-------------------+--------------------------------------------+ +| ``KEY_REFERENCE`` | Ref (reference) | ++-------------------+--------------------------------------------+ +| ``KEY_REFRESH`` | Refresh | ++-------------------+--------------------------------------------+ +| ``KEY_REPLACE`` | Replace | ++-------------------+--------------------------------------------+ +| ``KEY_RESTART`` | Restart | ++-------------------+--------------------------------------------+ +| ``KEY_RESUME`` | Resume | ++-------------------+--------------------------------------------+ +| ``KEY_SAVE`` | Save | ++-------------------+--------------------------------------------+ +| ``KEY_SBEG`` | Shifted Beg (beginning) | ++-------------------+--------------------------------------------+ +| ``KEY_SCANCEL`` | Shifted Cancel | ++-------------------+--------------------------------------------+ +| ``KEY_SCOMMAND`` | Shifted Command | ++-------------------+--------------------------------------------+ +| ``KEY_SCOPY`` | Shifted Copy | ++-------------------+--------------------------------------------+ +| ``KEY_SCREATE`` | Shifted Create | ++-------------------+--------------------------------------------+ +| ``KEY_SDC`` | Shifted Delete char | ++-------------------+--------------------------------------------+ +| ``KEY_SDL`` | Shifted Delete line | ++-------------------+--------------------------------------------+ +| ``KEY_SELECT`` | Select | ++-------------------+--------------------------------------------+ +| ``KEY_SEND`` | Shifted End | ++-------------------+--------------------------------------------+ +| ``KEY_SEOL`` | Shifted Clear line | ++-------------------+--------------------------------------------+ +| ``KEY_SEXIT`` | Shifted Dxit | ++-------------------+--------------------------------------------+ +| ``KEY_SFIND`` | Shifted Find | ++-------------------+--------------------------------------------+ +| ``KEY_SHELP`` | Shifted Help | ++-------------------+--------------------------------------------+ +| ``KEY_SHOME`` | Shifted Home | ++-------------------+--------------------------------------------+ +| ``KEY_SIC`` | Shifted Input | ++-------------------+--------------------------------------------+ +| ``KEY_SLEFT`` | Shifted Left arrow | ++-------------------+--------------------------------------------+ +| ``KEY_SMESSAGE`` | Shifted Message | ++-------------------+--------------------------------------------+ +| ``KEY_SMOVE`` | Shifted Move | ++-------------------+--------------------------------------------+ +| ``KEY_SNEXT`` | Shifted Next | ++-------------------+--------------------------------------------+ +| ``KEY_SOPTIONS`` | Shifted Options | ++-------------------+--------------------------------------------+ +| ``KEY_SPREVIOUS`` | Shifted Prev | ++-------------------+--------------------------------------------+ +| ``KEY_SPRINT`` | Shifted Print | ++-------------------+--------------------------------------------+ +| ``KEY_SREDO`` | Shifted Redo | ++-------------------+--------------------------------------------+ +| ``KEY_SREPLACE`` | Shifted Replace | ++-------------------+--------------------------------------------+ +| ``KEY_SRIGHT`` | Shifted Right arrow | ++-------------------+--------------------------------------------+ +| ``KEY_SRSUME`` | Shifted Resume | ++-------------------+--------------------------------------------+ +| ``KEY_SSAVE`` | Shifted Save | ++-------------------+--------------------------------------------+ +| ``KEY_SSUSPEND`` | Shifted Suspend | ++-------------------+--------------------------------------------+ +| ``KEY_SUNDO`` | Shifted Undo | ++-------------------+--------------------------------------------+ +| ``KEY_SUSPEND`` | Suspend | ++-------------------+--------------------------------------------+ +| ``KEY_UNDO`` | Undo | ++-------------------+--------------------------------------------+ +| ``KEY_MOUSE`` | Mouse event has occurred | ++-------------------+--------------------------------------------+ +| ``KEY_RESIZE`` | Terminal resize event | ++-------------------+--------------------------------------------+ +| ``KEY_MAX`` | Maximum key value | ++-------------------+--------------------------------------------+ + +On VT100s and their software emulations, such as X terminal emulators, there are +normally at least four function keys (:const:`KEY_F1`, :const:`KEY_F2`, +:const:`KEY_F3`, :const:`KEY_F4`) available, and the arrow keys mapped to +:const:`KEY_UP`, :const:`KEY_DOWN`, :const:`KEY_LEFT` and :const:`KEY_RIGHT` in +the obvious way. If your machine has a PC keyboard, it is safe to expect arrow +keys and twelve function keys (older PC keyboards may have only ten function +keys); also, the following keypad mappings are standard: + ++------------------+-----------+ +| Keycap | Constant | ++==================+===========+ +| :kbd:`Insert` | KEY_IC | ++------------------+-----------+ +| :kbd:`Delete` | KEY_DC | ++------------------+-----------+ +| :kbd:`Home` | KEY_HOME | ++------------------+-----------+ +| :kbd:`End` | KEY_END | ++------------------+-----------+ +| :kbd:`Page Up` | KEY_NPAGE | ++------------------+-----------+ +| :kbd:`Page Down` | KEY_PPAGE | ++------------------+-----------+ + +The following table lists characters from the alternate character set. These are +inherited from the VT100 terminal, and will generally be available on software +emulations such as X terminals. When there is no graphic available, curses +falls back on a crude printable ASCII approximation. + +.. note:: + + These are available only after :func:`initscr` has been called. + ++------------------+------------------------------------------+ +| ACS code | Meaning | ++==================+==========================================+ +| ``ACS_BBSS`` | alternate name for upper right corner | ++------------------+------------------------------------------+ +| ``ACS_BLOCK`` | solid square block | ++------------------+------------------------------------------+ +| ``ACS_BOARD`` | board of squares | ++------------------+------------------------------------------+ +| ``ACS_BSBS`` | alternate name for horizontal line | ++------------------+------------------------------------------+ +| ``ACS_BSSB`` | alternate name for upper left corner | ++------------------+------------------------------------------+ +| ``ACS_BSSS`` | alternate name for top tee | ++------------------+------------------------------------------+ +| ``ACS_BTEE`` | bottom tee | ++------------------+------------------------------------------+ +| ``ACS_BULLET`` | bullet | ++------------------+------------------------------------------+ +| ``ACS_CKBOARD`` | checker board (stipple) | ++------------------+------------------------------------------+ +| ``ACS_DARROW`` | arrow pointing down | ++------------------+------------------------------------------+ +| ``ACS_DEGREE`` | degree symbol | ++------------------+------------------------------------------+ +| ``ACS_DIAMOND`` | diamond | ++------------------+------------------------------------------+ +| ``ACS_GEQUAL`` | greater-than-or-equal-to | ++------------------+------------------------------------------+ +| ``ACS_HLINE`` | horizontal line | ++------------------+------------------------------------------+ +| ``ACS_LANTERN`` | lantern symbol | ++------------------+------------------------------------------+ +| ``ACS_LARROW`` | left arrow | ++------------------+------------------------------------------+ +| ``ACS_LEQUAL`` | less-than-or-equal-to | ++------------------+------------------------------------------+ +| ``ACS_LLCORNER`` | lower left-hand corner | ++------------------+------------------------------------------+ +| ``ACS_LRCORNER`` | lower right-hand corner | ++------------------+------------------------------------------+ +| ``ACS_LTEE`` | left tee | ++------------------+------------------------------------------+ +| ``ACS_NEQUAL`` | not-equal sign | ++------------------+------------------------------------------+ +| ``ACS_PI`` | letter pi | ++------------------+------------------------------------------+ +| ``ACS_PLMINUS`` | plus-or-minus sign | ++------------------+------------------------------------------+ +| ``ACS_PLUS`` | big plus sign | ++------------------+------------------------------------------+ +| ``ACS_RARROW`` | right arrow | ++------------------+------------------------------------------+ +| ``ACS_RTEE`` | right tee | ++------------------+------------------------------------------+ +| ``ACS_S1`` | scan line 1 | ++------------------+------------------------------------------+ +| ``ACS_S3`` | scan line 3 | ++------------------+------------------------------------------+ +| ``ACS_S7`` | scan line 7 | ++------------------+------------------------------------------+ +| ``ACS_S9`` | scan line 9 | ++------------------+------------------------------------------+ +| ``ACS_SBBS`` | alternate name for lower right corner | ++------------------+------------------------------------------+ +| ``ACS_SBSB`` | alternate name for vertical line | ++------------------+------------------------------------------+ +| ``ACS_SBSS`` | alternate name for right tee | ++------------------+------------------------------------------+ +| ``ACS_SSBB`` | alternate name for lower left corner | ++------------------+------------------------------------------+ +| ``ACS_SSBS`` | alternate name for bottom tee | ++------------------+------------------------------------------+ +| ``ACS_SSSB`` | alternate name for left tee | ++------------------+------------------------------------------+ +| ``ACS_SSSS`` | alternate name for crossover or big plus | ++------------------+------------------------------------------+ +| ``ACS_STERLING`` | pound sterling | ++------------------+------------------------------------------+ +| ``ACS_TTEE`` | top tee | ++------------------+------------------------------------------+ +| ``ACS_UARROW`` | up arrow | ++------------------+------------------------------------------+ +| ``ACS_ULCORNER`` | upper left corner | ++------------------+------------------------------------------+ +| ``ACS_URCORNER`` | upper right corner | ++------------------+------------------------------------------+ +| ``ACS_VLINE`` | vertical line | ++------------------+------------------------------------------+ + +The following table lists the predefined colors: + ++-------------------+----------------------------+ +| Constant | Color | ++===================+============================+ +| ``COLOR_BLACK`` | Black | ++-------------------+----------------------------+ +| ``COLOR_BLUE`` | Blue | ++-------------------+----------------------------+ +| ``COLOR_CYAN`` | Cyan (light greenish blue) | ++-------------------+----------------------------+ +| ``COLOR_GREEN`` | Green | ++-------------------+----------------------------+ +| ``COLOR_MAGENTA`` | Magenta (purplish red) | ++-------------------+----------------------------+ +| ``COLOR_RED`` | Red | ++-------------------+----------------------------+ +| ``COLOR_WHITE`` | White | ++-------------------+----------------------------+ +| ``COLOR_YELLOW`` | Yellow | ++-------------------+----------------------------+ + + +:mod:`curses.textpad` --- Text input widget for curses programs +=============================================================== + +.. module:: curses.textpad + :synopsis: Emacs-like input editing in a curses window. +.. moduleauthor:: Eric Raymond +.. sectionauthor:: Eric Raymond + + +.. versionadded:: 1.6 + +The :mod:`curses.textpad` module provides a :class:`Textbox` class that handles +elementary text editing in a curses window, supporting a set of keybindings +resembling those of Emacs (thus, also of Netscape Navigator, BBedit 6.x, +FrameMaker, and many other programs). The module also provides a +rectangle-drawing function useful for framing text boxes or for other purposes. + +The module :mod:`curses.textpad` defines the following function: + + +.. function:: rectangle(win, uly, ulx, lry, lrx) + + Draw a rectangle. The first argument must be a window object; the remaining + arguments are coordinates relative to that window. The second and third + arguments are the y and x coordinates of the upper left hand corner of the + rectangle to be drawn; the fourth and fifth arguments are the y and x + coordinates of the lower right hand corner. The rectangle will be drawn using + VT100/IBM PC forms characters on terminals that make this possible (including + xterm and most other software terminal emulators). Otherwise it will be drawn + with ASCII dashes, vertical bars, and plus signs. + + +.. _curses-textpad-objects: + +Textbox objects +--------------- + +You can instantiate a :class:`Textbox` object as follows: + + +.. class:: Textbox(win) + + Return a textbox widget object. The *win* argument should be a curses + :class:`WindowObject` in which the textbox is to be contained. The edit cursor + of the textbox is initially located at the upper left hand corner of the + containing window, with coordinates ``(0, 0)``. The instance's + :attr:`stripspaces` flag is initially on. + +:class:`Textbox` objects have the following methods: + + +.. method:: Textbox.edit([validator]) + + This is the entry point you will normally use. It accepts editing keystrokes + until one of the termination keystrokes is entered. If *validator* is supplied, + it must be a function. It will be called for each keystroke entered with the + keystroke as a parameter; command dispatch is done on the result. This method + returns the window contents as a string; whether blanks in the window are + included is affected by the :attr:`stripspaces` member. + + +.. method:: Textbox.do_command(ch) + + Process a single command keystroke. Here are the supported special keystrokes: + + +------------------+-------------------------------------------+ + | Keystroke | Action | + +==================+===========================================+ + | :kbd:`Control-A` | Go to left edge of window. | + +------------------+-------------------------------------------+ + | :kbd:`Control-B` | Cursor left, wrapping to previous line if | + | | appropriate. | + +------------------+-------------------------------------------+ + | :kbd:`Control-D` | Delete character under cursor. | + +------------------+-------------------------------------------+ + | :kbd:`Control-E` | Go to right edge (stripspaces off) or end | + | | of line (stripspaces on). | + +------------------+-------------------------------------------+ + | :kbd:`Control-F` | Cursor right, wrapping to next line when | + | | appropriate. | + +------------------+-------------------------------------------+ + | :kbd:`Control-G` | Terminate, returning the window contents. | + +------------------+-------------------------------------------+ + | :kbd:`Control-H` | Delete character backward. | + +------------------+-------------------------------------------+ + | :kbd:`Control-J` | Terminate if the window is 1 line, | + | | otherwise insert newline. | + +------------------+-------------------------------------------+ + | :kbd:`Control-K` | If line is blank, delete it, otherwise | + | | clear to end of line. | + +------------------+-------------------------------------------+ + | :kbd:`Control-L` | Refresh screen. | + +------------------+-------------------------------------------+ + | :kbd:`Control-N` | Cursor down; move down one line. | + +------------------+-------------------------------------------+ + | :kbd:`Control-O` | Insert a blank line at cursor location. | + +------------------+-------------------------------------------+ + | :kbd:`Control-P` | Cursor up; move up one line. | + +------------------+-------------------------------------------+ + + Move operations do nothing if the cursor is at an edge where the movement is not + possible. The following synonyms are supported where possible: + + +------------------------+------------------+ + | Constant | Keystroke | + +========================+==================+ + | :const:`KEY_LEFT` | :kbd:`Control-B` | + +------------------------+------------------+ + | :const:`KEY_RIGHT` | :kbd:`Control-F` | + +------------------------+------------------+ + | :const:`KEY_UP` | :kbd:`Control-P` | + +------------------------+------------------+ + | :const:`KEY_DOWN` | :kbd:`Control-N` | + +------------------------+------------------+ + | :const:`KEY_BACKSPACE` | :kbd:`Control-h` | + +------------------------+------------------+ + + All other keystrokes are treated as a command to insert the given character and + move right (with line wrapping). + + +.. method:: Textbox.gather() + + This method returns the window contents as a string; whether blanks in the + window are included is affected by the :attr:`stripspaces` member. + + +.. attribute:: Textbox.stripspaces + + This data member is a flag which controls the interpretation of blanks in the + window. When it is on, trailing blanks on each line are ignored; any cursor + motion that would land the cursor on a trailing blank goes to the end of that + line instead, and trailing blanks are stripped when the window contents are + gathered. + + +:mod:`curses.wrapper` --- Terminal handler for curses programs +============================================================== + +.. module:: curses.wrapper + :synopsis: Terminal configuration wrapper for curses programs. +.. moduleauthor:: Eric Raymond +.. sectionauthor:: Eric Raymond + + +.. versionadded:: 1.6 + +This module supplies one function, :func:`wrapper`, which runs another function +which should be the rest of your curses-using application. If the application +raises an exception, :func:`wrapper` will restore the terminal to a sane state +before re-raising the exception and generating a traceback. + + +.. function:: wrapper(func, ...) + + Wrapper function that initializes curses and calls another function, *func*, + restoring normal keyboard/screen behavior on error. The callable object *func* + is then passed the main window 'stdscr' as its first argument, followed by any + other arguments passed to :func:`wrapper`. + +Before calling the hook function, :func:`wrapper` turns on cbreak mode, turns +off echo, enables the terminal keypad, and initializes colors if the terminal +has color support. On exit (whether normally or by exception) it restores +cooked mode, turns on echo, and disables the terminal keypad. + diff --git a/Doc/library/custominterp.rst b/Doc/library/custominterp.rst new file mode 100644 index 0000000..2a9f0a4 --- /dev/null +++ b/Doc/library/custominterp.rst @@ -0,0 +1,20 @@ + +.. _custominterp: + +************************** +Custom Python Interpreters +************************** + +The modules described in this chapter allow writing interfaces similar to +Python's interactive interpreter. If you want a Python interpreter that +supports some special feature in addition to the Python language, you should +look at the :mod:`code` module. (The :mod:`codeop` module is lower-level, used +to support compiling a possibly-incomplete chunk of Python code.) + +The full list of modules described in this chapter is: + + +.. toctree:: + + code.rst + codeop.rst diff --git a/Doc/library/datatypes.rst b/Doc/library/datatypes.rst new file mode 100644 index 0000000..4cd042d --- /dev/null +++ b/Doc/library/datatypes.rst @@ -0,0 +1,37 @@ + +.. _datatypes: + +********** +Data Types +********** + +The modules described in this chapter provide a variety of specialized data +types such as dates and times, fixed-type arrays, heap queues, synchronized +queues, and sets. + +Python also provides some built-in data types, in particular, +:class:`dict`, :class:`list`, :class:`set` and :class:`frozenset`, and +:class:`tuple`. The :class:`str` class can be used to handle binary data +and 8-bit text, and the :class:`unicode` class to handle Unicode text. + +The following modules are documented in this chapter: + + +.. toctree:: + + datetime.rst + calendar.rst + collections.rst + heapq.rst + bisect.rst + array.rst + sched.rst + mutex.rst + queue.rst + weakref.rst + userdict.rst + types.rst + new.rst + copy.rst + pprint.rst + repr.rst diff --git a/Doc/library/datetime.rst b/Doc/library/datetime.rst new file mode 100644 index 0000000..24d4f69 --- /dev/null +++ b/Doc/library/datetime.rst @@ -0,0 +1,1348 @@ +.. % XXX what order should the types be discussed in? + + +:mod:`datetime` --- Basic date and time types +============================================= + +.. module:: datetime + :synopsis: Basic date and time types. +.. moduleauthor:: Tim Peters +.. sectionauthor:: Tim Peters +.. sectionauthor:: A.M. Kuchling + + +.. versionadded:: 2.3 + +The :mod:`datetime` module supplies classes for manipulating dates and times in +both simple and complex ways. While date and time arithmetic is supported, the +focus of the implementation is on efficient member extraction for output +formatting and manipulation. For related +functionality, see also the :mod:`time` and :mod:`calendar` modules. + +There are two kinds of date and time objects: "naive" and "aware". This +distinction refers to whether the object has any notion of time zone, daylight +saving time, or other kind of algorithmic or political time adjustment. Whether +a naive :class:`datetime` object represents Coordinated Universal Time (UTC), +local time, or time in some other timezone is purely up to the program, just +like it's up to the program whether a particular number represents metres, +miles, or mass. Naive :class:`datetime` objects are easy to understand and to +work with, at the cost of ignoring some aspects of reality. + +For applications requiring more, :class:`datetime` and :class:`time` objects +have an optional time zone information member, :attr:`tzinfo`, that can contain +an instance of a subclass of the abstract :class:`tzinfo` class. These +:class:`tzinfo` objects capture information about the offset from UTC time, the +time zone name, and whether Daylight Saving Time is in effect. Note that no +concrete :class:`tzinfo` classes are supplied by the :mod:`datetime` module. +Supporting timezones at whatever level of detail is required is up to the +application. The rules for time adjustment across the world are more political +than rational, and there is no standard suitable for every application. + +The :mod:`datetime` module exports the following constants: + + +.. data:: MINYEAR + + The smallest year number allowed in a :class:`date` or :class:`datetime` object. + :const:`MINYEAR` is ``1``. + + +.. data:: MAXYEAR + + The largest year number allowed in a :class:`date` or :class:`datetime` object. + :const:`MAXYEAR` is ``9999``. + + +.. seealso:: + + Module :mod:`calendar` + General calendar related functions. + + Module :mod:`time` + Time access and conversions. + + +Available Types +--------------- + + +.. class:: date + + An idealized naive date, assuming the current Gregorian calendar always was, and + always will be, in effect. Attributes: :attr:`year`, :attr:`month`, and + :attr:`day`. + + +.. class:: time + + An idealized time, independent of any particular day, assuming that every day + has exactly 24\*60\*60 seconds (there is no notion of "leap seconds" here). + Attributes: :attr:`hour`, :attr:`minute`, :attr:`second`, :attr:`microsecond`, + and :attr:`tzinfo`. + + +.. class:: datetime + + A combination of a date and a time. Attributes: :attr:`year`, :attr:`month`, + :attr:`day`, :attr:`hour`, :attr:`minute`, :attr:`second`, :attr:`microsecond`, + and :attr:`tzinfo`. + + +.. class:: timedelta + + A duration expressing the difference between two :class:`date`, :class:`time`, + or :class:`datetime` instances to microsecond resolution. + + +.. class:: tzinfo + + An abstract base class for time zone information objects. These are used by the + :class:`datetime` and :class:`time` classes to provide a customizable notion of + time adjustment (for example, to account for time zone and/or daylight saving + time). + +Objects of these types are immutable. + +Objects of the :class:`date` type are always naive. + +An object *d* of type :class:`time` or :class:`datetime` may be naive or aware. +*d* is aware if ``d.tzinfo`` is not ``None`` and ``d.tzinfo.utcoffset(d)`` does +not return ``None``. If ``d.tzinfo`` is ``None``, or if ``d.tzinfo`` is not +``None`` but ``d.tzinfo.utcoffset(d)`` returns ``None``, *d* is naive. + +The distinction between naive and aware doesn't apply to :class:`timedelta` +objects. + +Subclass relationships:: + + object + timedelta + tzinfo + time + date + datetime + + +.. _datetime-timedelta: + +:class:`timedelta` Objects +-------------------------- + +A :class:`timedelta` object represents a duration, the difference between two +dates or times. + + +.. class:: timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]]]) + + All arguments are optional and default to ``0``. Arguments may be ints, longs, + or floats, and may be positive or negative. + + Only *days*, *seconds* and *microseconds* are stored internally. Arguments are + converted to those units: + + * A millisecond is converted to 1000 microseconds. + * A minute is converted to 60 seconds. + * An hour is converted to 3600 seconds. + * A week is converted to 7 days. + + and days, seconds and microseconds are then normalized so that the + representation is unique, with + + * ``0 <= microseconds < 1000000`` + * ``0 <= seconds < 3600*24`` (the number of seconds in one day) + * ``-999999999 <= days <= 999999999`` + + If any argument is a float and there are fractional microseconds, the fractional + microseconds left over from all arguments are combined and their sum is rounded + to the nearest microsecond. If no argument is a float, the conversion and + normalization processes are exact (no information is lost). + + If the normalized value of days lies outside the indicated range, + :exc:`OverflowError` is raised. + + Note that normalization of negative values may be surprising at first. For + example, :: + + >>> d = timedelta(microseconds=-1) + >>> (d.days, d.seconds, d.microseconds) + (-1, 86399, 999999) + +Class attributes are: + + +.. attribute:: timedelta.min + + The most negative :class:`timedelta` object, ``timedelta(-999999999)``. + + +.. attribute:: timedelta.max + + The most positive :class:`timedelta` object, ``timedelta(days=999999999, + hours=23, minutes=59, seconds=59, microseconds=999999)``. + + +.. attribute:: timedelta.resolution + + The smallest possible difference between non-equal :class:`timedelta` objects, + ``timedelta(microseconds=1)``. + +Note that, because of normalization, ``timedelta.max`` > ``-timedelta.min``. +``-timedelta.max`` is not representable as a :class:`timedelta` object. + +Instance attributes (read-only): + ++------------------+--------------------------------------------+ +| Attribute | Value | ++==================+============================================+ +| ``days`` | Between -999999999 and 999999999 inclusive | ++------------------+--------------------------------------------+ +| ``seconds`` | Between 0 and 86399 inclusive | ++------------------+--------------------------------------------+ +| ``microseconds`` | Between 0 and 999999 inclusive | ++------------------+--------------------------------------------+ + +Supported operations: + +.. % XXX this table is too wide! + ++--------------------------------+-----------------------------------------------+ +| Operation | Result | ++================================+===============================================+ +| ``t1 = t2 + t3`` | Sum of *t2* and *t3*. Afterwards *t1*-*t2* == | +| | *t3* and *t1*-*t3* == *t2* are true. (1) | ++--------------------------------+-----------------------------------------------+ +| ``t1 = t2 - t3`` | Difference of *t2* and *t3*. Afterwards *t1* | +| | == *t2* - *t3* and *t2* == *t1* + *t3* are | +| | true. (1) | ++--------------------------------+-----------------------------------------------+ +| ``t1 = t2 * i or t1 = i * t2`` | Delta multiplied by an integer or long. | +| | Afterwards *t1* // i == *t2* is true, | +| | provided ``i != 0``. | ++--------------------------------+-----------------------------------------------+ +| | In general, *t1* \* i == *t1* \* (i-1) + *t1* | +| | is true. (1) | ++--------------------------------+-----------------------------------------------+ +| ``t1 = t2 // i`` | The floor is computed and the remainder (if | +| | any) is thrown away. (3) | ++--------------------------------+-----------------------------------------------+ +| ``+t1`` | Returns a :class:`timedelta` object with the | +| | same value. (2) | ++--------------------------------+-----------------------------------------------+ +| ``-t1`` | equivalent to :class:`timedelta`\ | +| | (-*t1.days*, -*t1.seconds*, | +| | -*t1.microseconds*), and to *t1*\* -1. (1)(4) | ++--------------------------------+-----------------------------------------------+ +| ``abs(t)`` | equivalent to +*t* when ``t.days >= 0``, and | +| | to -*t* when ``t.days < 0``. (2) | ++--------------------------------+-----------------------------------------------+ + +Notes: + +(1) + This is exact, but may overflow. + +(2) + This is exact, and cannot overflow. + +(3) + Division by 0 raises :exc:`ZeroDivisionError`. + +(4) + -*timedelta.max* is not representable as a :class:`timedelta` object. + +In addition to the operations listed above :class:`timedelta` objects support +certain additions and subtractions with :class:`date` and :class:`datetime` +objects (see below). + +Comparisons of :class:`timedelta` objects are supported with the +:class:`timedelta` object representing the smaller duration considered to be the +smaller timedelta. In order to stop mixed-type comparisons from falling back to +the default comparison by object address, when a :class:`timedelta` object is +compared to an object of a different type, :exc:`TypeError` is raised unless the +comparison is ``==`` or ``!=``. The latter cases return :const:`False` or +:const:`True`, respectively. + +:class:`timedelta` objects are hashable (usable as dictionary keys), support +efficient pickling, and in Boolean contexts, a :class:`timedelta` object is +considered to be true if and only if it isn't equal to ``timedelta(0)``. + + +.. _datetime-date: + +:class:`date` Objects +--------------------- + +A :class:`date` object represents a date (year, month and day) in an idealized +calendar, the current Gregorian calendar indefinitely extended in both +directions. January 1 of year 1 is called day number 1, January 2 of year 1 is +called day number 2, and so on. This matches the definition of the "proleptic +Gregorian" calendar in Dershowitz and Reingold's book Calendrical Calculations, +where it's the base calendar for all computations. See the book for algorithms +for converting between proleptic Gregorian ordinals and many other calendar +systems. + + +.. class:: date(year, month, day) + + All arguments are required. Arguments may be ints or longs, in the following + ranges: + + * ``MINYEAR <= year <= MAXYEAR`` + * ``1 <= month <= 12`` + * ``1 <= day <= number of days in the given month and year`` + + If an argument outside those ranges is given, :exc:`ValueError` is raised. + +Other constructors, all class methods: + + +.. method:: date.today() + + Return the current local date. This is equivalent to + ``date.fromtimestamp(time.time())``. + + +.. method:: date.fromtimestamp(timestamp) + + Return the local date corresponding to the POSIX timestamp, such as is returned + by :func:`time.time`. This may raise :exc:`ValueError`, if the timestamp is out + of the range of values supported by the platform C :cfunc:`localtime` function. + It's common for this to be restricted to years from 1970 through 2038. Note + that on non-POSIX systems that include leap seconds in their notion of a + timestamp, leap seconds are ignored by :meth:`fromtimestamp`. + + +.. method:: date.fromordinal(ordinal) + + Return the date corresponding to the proleptic Gregorian ordinal, where January + 1 of year 1 has ordinal 1. :exc:`ValueError` is raised unless ``1 <= ordinal <= + date.max.toordinal()``. For any date *d*, ``date.fromordinal(d.toordinal()) == + d``. + +Class attributes: + + +.. attribute:: date.min + + The earliest representable date, ``date(MINYEAR, 1, 1)``. + + +.. attribute:: date.max + + The latest representable date, ``date(MAXYEAR, 12, 31)``. + + +.. attribute:: date.resolution + + The smallest possible difference between non-equal date objects, + ``timedelta(days=1)``. + +Instance attributes (read-only): + + +.. attribute:: date.year + + Between :const:`MINYEAR` and :const:`MAXYEAR` inclusive. + + +.. attribute:: date.month + + Between 1 and 12 inclusive. + + +.. attribute:: date.day + + Between 1 and the number of days in the given month of the given year. + +Supported operations: + ++-------------------------------+----------------------------------------------+ +| Operation | Result | ++===============================+==============================================+ +| ``date2 = date1 + timedelta`` | *date2* is ``timedelta.days`` days removed | +| | from *date1*. (1) | ++-------------------------------+----------------------------------------------+ +| ``date2 = date1 - timedelta`` | Computes *date2* such that ``date2 + | +| | timedelta == date1``. (2) | ++-------------------------------+----------------------------------------------+ +| ``timedelta = date1 - date2`` | \(3) | ++-------------------------------+----------------------------------------------+ +| ``date1 < date2`` | *date1* is considered less than *date2* when | +| | *date1* precedes *date2* in time. (4) | ++-------------------------------+----------------------------------------------+ + +Notes: + +(1) + *date2* is moved forward in time if ``timedelta.days > 0``, or backward if + ``timedelta.days < 0``. Afterward ``date2 - date1 == timedelta.days``. + ``timedelta.seconds`` and ``timedelta.microseconds`` are ignored. + :exc:`OverflowError` is raised if ``date2.year`` would be smaller than + :const:`MINYEAR` or larger than :const:`MAXYEAR`. + +(2) + This isn't quite equivalent to date1 + (-timedelta), because -timedelta in + isolation can overflow in cases where date1 - timedelta does not. + ``timedelta.seconds`` and ``timedelta.microseconds`` are ignored. + +(3) + This is exact, and cannot overflow. timedelta.seconds and + timedelta.microseconds are 0, and date2 + timedelta == date1 after. + +(4) + In other words, ``date1 < date2`` if and only if ``date1.toordinal() < + date2.toordinal()``. In order to stop comparison from falling back to the + default scheme of comparing object addresses, date comparison normally raises + :exc:`TypeError` if the other comparand isn't also a :class:`date` object. + However, ``NotImplemented`` is returned instead if the other comparand has a + :meth:`timetuple` attribute. This hook gives other kinds of date objects a + chance at implementing mixed-type comparison. If not, when a :class:`date` + object is compared to an object of a different type, :exc:`TypeError` is raised + unless the comparison is ``==`` or ``!=``. The latter cases return + :const:`False` or :const:`True`, respectively. + +Dates can be used as dictionary keys. In Boolean contexts, all :class:`date` +objects are considered to be true. + +Instance methods: + + +.. method:: date.replace(year, month, day) + + Return a date with the same value, except for those members given new values by + whichever keyword arguments are specified. For example, if ``d == date(2002, + 12, 31)``, then ``d.replace(day=26) == date(2002, 12, 26)``. + + +.. method:: date.timetuple() + + Return a :class:`time.struct_time` such as returned by :func:`time.localtime`. + The hours, minutes and seconds are 0, and the DST flag is -1. ``d.timetuple()`` + is equivalent to ``time.struct_time((d.year, d.month, d.day, 0, 0, 0, + d.weekday(), d.toordinal() - date(d.year, 1, 1).toordinal() + 1, -1))`` + + +.. method:: date.toordinal() + + Return the proleptic Gregorian ordinal of the date, where January 1 of year 1 + has ordinal 1. For any :class:`date` object *d*, + ``date.fromordinal(d.toordinal()) == d``. + + +.. method:: date.weekday() + + Return the day of the week as an integer, where Monday is 0 and Sunday is 6. + For example, ``date(2002, 12, 4).weekday() == 2``, a Wednesday. See also + :meth:`isoweekday`. + + +.. method:: date.isoweekday() + + Return the day of the week as an integer, where Monday is 1 and Sunday is 7. + For example, ``date(2002, 12, 4).isoweekday() == 3``, a Wednesday. See also + :meth:`weekday`, :meth:`isocalendar`. + + +.. method:: date.isocalendar() + + Return a 3-tuple, (ISO year, ISO week number, ISO weekday). + + The ISO calendar is a widely used variant of the Gregorian calendar. See + http://www.phys.uu.nl/ vgent/calendar/isocalendar.htm for a good explanation. + + The ISO year consists of 52 or 53 full weeks, and where a week starts on a + Monday and ends on a Sunday. The first week of an ISO year is the first + (Gregorian) calendar week of a year containing a Thursday. This is called week + number 1, and the ISO year of that Thursday is the same as its Gregorian year. + + For example, 2004 begins on a Thursday, so the first week of ISO year 2004 + begins on Monday, 29 Dec 2003 and ends on Sunday, 4 Jan 2004, so that + ``date(2003, 12, 29).isocalendar() == (2004, 1, 1)`` and ``date(2004, 1, + 4).isocalendar() == (2004, 1, 7)``. + + +.. method:: date.isoformat() + + Return a string representing the date in ISO 8601 format, 'YYYY-MM-DD'. For + example, ``date(2002, 12, 4).isoformat() == '2002-12-04'``. + + +.. method:: date.__str__() + + For a date *d*, ``str(d)`` is equivalent to ``d.isoformat()``. + + +.. method:: date.ctime() + + Return a string representing the date, for example ``date(2002, 12, + 4).ctime() == 'Wed Dec 4 00:00:00 2002'``. ``d.ctime()`` is equivalent to + ``time.ctime(time.mktime(d.timetuple()))`` on platforms where the native C + :cfunc:`ctime` function (which :func:`time.ctime` invokes, but which + :meth:`date.ctime` does not invoke) conforms to the C standard. + + +.. method:: date.strftime(format) + + Return a string representing the date, controlled by an explicit format string. + Format codes referring to hours, minutes or seconds will see 0 values. See + section :ref:`strftime-behavior`. + + +.. _datetime-datetime: + +:class:`datetime` Objects +------------------------- + +A :class:`datetime` object is a single object containing all the information +from a :class:`date` object and a :class:`time` object. Like a :class:`date` +object, :class:`datetime` assumes the current Gregorian calendar extended in +both directions; like a time object, :class:`datetime` assumes there are exactly +3600\*24 seconds in every day. + +Constructor: + + +.. class:: datetime(year, month, day[, hour[, minute[, second[, microsecond[, tzinfo]]]]]) + + The year, month and day arguments are required. *tzinfo* may be ``None``, or an + instance of a :class:`tzinfo` subclass. The remaining arguments may be ints or + longs, in the following ranges: + + * ``MINYEAR <= year <= MAXYEAR`` + * ``1 <= month <= 12`` + * ``1 <= day <= number of days in the given month and year`` + * ``0 <= hour < 24`` + * ``0 <= minute < 60`` + * ``0 <= second < 60`` + * ``0 <= microsecond < 1000000`` + + If an argument outside those ranges is given, :exc:`ValueError` is raised. + +Other constructors, all class methods: + + +.. method:: datetime.today() + + Return the current local datetime, with :attr:`tzinfo` ``None``. This is + equivalent to ``datetime.fromtimestamp(time.time())``. See also :meth:`now`, + :meth:`fromtimestamp`. + + +.. method:: datetime.now([tz]) + + Return the current local date and time. If optional argument *tz* is ``None`` + or not specified, this is like :meth:`today`, but, if possible, supplies more + precision than can be gotten from going through a :func:`time.time` timestamp + (for example, this may be possible on platforms supplying the C + :cfunc:`gettimeofday` function). + + Else *tz* must be an instance of a class :class:`tzinfo` subclass, and the + current date and time are converted to *tz*'s time zone. In this case the + result is equivalent to ``tz.fromutc(datetime.utcnow().replace(tzinfo=tz))``. + See also :meth:`today`, :meth:`utcnow`. + + +.. method:: datetime.utcnow() + + Return the current UTC date and time, with :attr:`tzinfo` ``None``. This is like + :meth:`now`, but returns the current UTC date and time, as a naive + :class:`datetime` object. See also :meth:`now`. + + +.. method:: datetime.fromtimestamp(timestamp[, tz]) + + Return the local date and time corresponding to the POSIX timestamp, such as is + returned by :func:`time.time`. If optional argument *tz* is ``None`` or not + specified, the timestamp is converted to the platform's local date and time, and + the returned :class:`datetime` object is naive. + + Else *tz* must be an instance of a class :class:`tzinfo` subclass, and the + timestamp is converted to *tz*'s time zone. In this case the result is + equivalent to + ``tz.fromutc(datetime.utcfromtimestamp(timestamp).replace(tzinfo=tz))``. + + :meth:`fromtimestamp` may raise :exc:`ValueError`, if the timestamp is out of + the range of values supported by the platform C :cfunc:`localtime` or + :cfunc:`gmtime` functions. It's common for this to be restricted to years in + 1970 through 2038. Note that on non-POSIX systems that include leap seconds in + their notion of a timestamp, leap seconds are ignored by :meth:`fromtimestamp`, + and then it's possible to have two timestamps differing by a second that yield + identical :class:`datetime` objects. See also :meth:`utcfromtimestamp`. + + +.. method:: datetime.utcfromtimestamp(timestamp) + + Return the UTC :class:`datetime` corresponding to the POSIX timestamp, with + :attr:`tzinfo` ``None``. This may raise :exc:`ValueError`, if the timestamp is + out of the range of values supported by the platform C :cfunc:`gmtime` function. + It's common for this to be restricted to years in 1970 through 2038. See also + :meth:`fromtimestamp`. + + +.. method:: datetime.fromordinal(ordinal) + + Return the :class:`datetime` corresponding to the proleptic Gregorian ordinal, + where January 1 of year 1 has ordinal 1. :exc:`ValueError` is raised unless ``1 + <= ordinal <= datetime.max.toordinal()``. The hour, minute, second and + microsecond of the result are all 0, and :attr:`tzinfo` is ``None``. + + +.. method:: datetime.combine(date, time) + + Return a new :class:`datetime` object whose date members are equal to the given + :class:`date` object's, and whose time and :attr:`tzinfo` members are equal to + the given :class:`time` object's. For any :class:`datetime` object *d*, ``d == + datetime.combine(d.date(), d.timetz())``. If date is a :class:`datetime` + object, its time and :attr:`tzinfo` members are ignored. + + +.. method:: datetime.strptime(date_string, format) + + Return a :class:`datetime` corresponding to *date_string*, parsed according to + *format*. This is equivalent to ``datetime(*(time.strptime(date_string, + format)[0:6]))``. :exc:`ValueError` is raised if the date_string and format + can't be parsed by :func:`time.strptime` or if it returns a value which isn't a + time tuple. + + .. versionadded:: 2.5 + +Class attributes: + + +.. attribute:: datetime.min + + The earliest representable :class:`datetime`, ``datetime(MINYEAR, 1, 1, + tzinfo=None)``. + + +.. attribute:: datetime.max + + The latest representable :class:`datetime`, ``datetime(MAXYEAR, 12, 31, 23, 59, + 59, 999999, tzinfo=None)``. + + +.. attribute:: datetime.resolution + + The smallest possible difference between non-equal :class:`datetime` objects, + ``timedelta(microseconds=1)``. + +Instance attributes (read-only): + + +.. attribute:: datetime.year + + Between :const:`MINYEAR` and :const:`MAXYEAR` inclusive. + + +.. attribute:: datetime.month + + Between 1 and 12 inclusive. + + +.. attribute:: datetime.day + + Between 1 and the number of days in the given month of the given year. + + +.. attribute:: datetime.hour + + In ``range(24)``. + + +.. attribute:: datetime.minute + + In ``range(60)``. + + +.. attribute:: datetime.second + + In ``range(60)``. + + +.. attribute:: datetime.microsecond + + In ``range(1000000)``. + + +.. attribute:: datetime.tzinfo + + The object passed as the *tzinfo* argument to the :class:`datetime` constructor, + or ``None`` if none was passed. + +Supported operations: + ++---------------------------------------+-------------------------------+ +| Operation | Result | ++=======================================+===============================+ +| ``datetime2 = datetime1 + timedelta`` | \(1) | ++---------------------------------------+-------------------------------+ +| ``datetime2 = datetime1 - timedelta`` | \(2) | ++---------------------------------------+-------------------------------+ +| ``timedelta = datetime1 - datetime2`` | \(3) | ++---------------------------------------+-------------------------------+ +| ``datetime1 < datetime2`` | Compares :class:`datetime` to | +| | :class:`datetime`. (4) | ++---------------------------------------+-------------------------------+ + +(1) + datetime2 is a duration of timedelta removed from datetime1, moving forward in + time if ``timedelta.days`` > 0, or backward if ``timedelta.days`` < 0. The + result has the same :attr:`tzinfo` member as the input datetime, and datetime2 - + datetime1 == timedelta after. :exc:`OverflowError` is raised if datetime2.year + would be smaller than :const:`MINYEAR` or larger than :const:`MAXYEAR`. Note + that no time zone adjustments are done even if the input is an aware object. + +(2) + Computes the datetime2 such that datetime2 + timedelta == datetime1. As for + addition, the result has the same :attr:`tzinfo` member as the input datetime, + and no time zone adjustments are done even if the input is aware. This isn't + quite equivalent to datetime1 + (-timedelta), because -timedelta in isolation + can overflow in cases where datetime1 - timedelta does not. + +(3) + Subtraction of a :class:`datetime` from a :class:`datetime` is defined only if + both operands are naive, or if both are aware. If one is aware and the other is + naive, :exc:`TypeError` is raised. + + If both are naive, or both are aware and have the same :attr:`tzinfo` member, + the :attr:`tzinfo` members are ignored, and the result is a :class:`timedelta` + object *t* such that ``datetime2 + t == datetime1``. No time zone adjustments + are done in this case. + + If both are aware and have different :attr:`tzinfo` members, ``a-b`` acts as if + *a* and *b* were first converted to naive UTC datetimes first. The result is + ``(a.replace(tzinfo=None) - a.utcoffset()) - (b.replace(tzinfo=None) - + b.utcoffset())`` except that the implementation never overflows. + +(4) + *datetime1* is considered less than *datetime2* when *datetime1* precedes + *datetime2* in time. + + If one comparand is naive and the other is aware, :exc:`TypeError` is raised. + If both comparands are aware, and have the same :attr:`tzinfo` member, the + common :attr:`tzinfo` member is ignored and the base datetimes are compared. If + both comparands are aware and have different :attr:`tzinfo` members, the + comparands are first adjusted by subtracting their UTC offsets (obtained from + ``self.utcoffset()``). + + .. note:: + + In order to stop comparison from falling back to the default scheme of comparing + object addresses, datetime comparison normally raises :exc:`TypeError` if the + other comparand isn't also a :class:`datetime` object. However, + ``NotImplemented`` is returned instead if the other comparand has a + :meth:`timetuple` attribute. This hook gives other kinds of date objects a + chance at implementing mixed-type comparison. If not, when a :class:`datetime` + object is compared to an object of a different type, :exc:`TypeError` is raised + unless the comparison is ``==`` or ``!=``. The latter cases return + :const:`False` or :const:`True`, respectively. + +:class:`datetime` objects can be used as dictionary keys. In Boolean contexts, +all :class:`datetime` objects are considered to be true. + +Instance methods: + + +.. method:: datetime.date() + + Return :class:`date` object with same year, month and day. + + +.. method:: datetime.time() + + Return :class:`time` object with same hour, minute, second and microsecond. + :attr:`tzinfo` is ``None``. See also method :meth:`timetz`. + + +.. method:: datetime.timetz() + + Return :class:`time` object with same hour, minute, second, microsecond, and + tzinfo members. See also method :meth:`time`. + + +.. method:: datetime.replace([year[, month[, day[, hour[, minute[, second[, microsecond[, tzinfo]]]]]]]]) + + Return a datetime with the same members, except for those members given new + values by whichever keyword arguments are specified. Note that ``tzinfo=None`` + can be specified to create a naive datetime from an aware datetime with no + conversion of date and time members. + + +.. method:: datetime.astimezone(tz) + + Return a :class:`datetime` object with new :attr:`tzinfo` member *tz*, adjusting + the date and time members so the result is the same UTC time as *self*, but in + *tz*'s local time. + + *tz* must be an instance of a :class:`tzinfo` subclass, and its + :meth:`utcoffset` and :meth:`dst` methods must not return ``None``. *self* must + be aware (``self.tzinfo`` must not be ``None``, and ``self.utcoffset()`` must + not return ``None``). + + If ``self.tzinfo`` is *tz*, ``self.astimezone(tz)`` is equal to *self*: no + adjustment of date or time members is performed. Else the result is local time + in time zone *tz*, representing the same UTC time as *self*: after ``astz = + dt.astimezone(tz)``, ``astz - astz.utcoffset()`` will usually have the same date + and time members as ``dt - dt.utcoffset()``. The discussion of class + :class:`tzinfo` explains the cases at Daylight Saving Time transition boundaries + where this cannot be achieved (an issue only if *tz* models both standard and + daylight time). + + If you merely want to attach a time zone object *tz* to a datetime *dt* without + adjustment of date and time members, use ``dt.replace(tzinfo=tz)``. If you + merely want to remove the time zone object from an aware datetime *dt* without + conversion of date and time members, use ``dt.replace(tzinfo=None)``. + + Note that the default :meth:`tzinfo.fromutc` method can be overridden in a + :class:`tzinfo` subclass to affect the result returned by :meth:`astimezone`. + Ignoring error cases, :meth:`astimezone` acts like:: + + def astimezone(self, tz): + if self.tzinfo is tz: + return self + # Convert self to UTC, and attach the new time zone object. + utc = (self - self.utcoffset()).replace(tzinfo=tz) + # Convert from UTC to tz's local time. + return tz.fromutc(utc) + + +.. method:: datetime.utcoffset() + + If :attr:`tzinfo` is ``None``, returns ``None``, else returns + ``self.tzinfo.utcoffset(self)``, and raises an exception if the latter doesn't + return ``None``, or a :class:`timedelta` object representing a whole number of + minutes with magnitude less than one day. + + +.. method:: datetime.dst() + + If :attr:`tzinfo` is ``None``, returns ``None``, else returns + ``self.tzinfo.dst(self)``, and raises an exception if the latter doesn't return + ``None``, or a :class:`timedelta` object representing a whole number of minutes + with magnitude less than one day. + + +.. method:: datetime.tzname() + + If :attr:`tzinfo` is ``None``, returns ``None``, else returns + ``self.tzinfo.tzname(self)``, raises an exception if the latter doesn't return + ``None`` or a string object, + + +.. method:: datetime.timetuple() + + Return a :class:`time.struct_time` such as returned by :func:`time.localtime`. + ``d.timetuple()`` is equivalent to ``time.struct_time((d.year, d.month, d.day, + d.hour, d.minute, d.second, d.weekday(), d.toordinal() - date(d.year, 1, + 1).toordinal() + 1, dst))`` The :attr:`tm_isdst` flag of the result is set + according to the :meth:`dst` method: :attr:`tzinfo` is ``None`` or :meth:`dst` + returns ``None``, :attr:`tm_isdst` is set to ``-1``; else if :meth:`dst` + returns a non-zero value, :attr:`tm_isdst` is set to ``1``; else ``tm_isdst`` is + set to ``0``. + + +.. method:: datetime.utctimetuple() + + If :class:`datetime` instance *d* is naive, this is the same as + ``d.timetuple()`` except that :attr:`tm_isdst` is forced to 0 regardless of what + ``d.dst()`` returns. DST is never in effect for a UTC time. + + If *d* is aware, *d* is normalized to UTC time, by subtracting + ``d.utcoffset()``, and a :class:`time.struct_time` for the normalized time is + returned. :attr:`tm_isdst` is forced to 0. Note that the result's + :attr:`tm_year` member may be :const:`MINYEAR`\ -1 or :const:`MAXYEAR`\ +1, if + *d*.year was ``MINYEAR`` or ``MAXYEAR`` and UTC adjustment spills over a year + boundary. + + +.. method:: datetime.toordinal() + + Return the proleptic Gregorian ordinal of the date. The same as + ``self.date().toordinal()``. + + +.. method:: datetime.weekday() + + Return the day of the week as an integer, where Monday is 0 and Sunday is 6. + The same as ``self.date().weekday()``. See also :meth:`isoweekday`. + + +.. method:: datetime.isoweekday() + + Return the day of the week as an integer, where Monday is 1 and Sunday is 7. + The same as ``self.date().isoweekday()``. See also :meth:`weekday`, + :meth:`isocalendar`. + + +.. method:: datetime.isocalendar() + + Return a 3-tuple, (ISO year, ISO week number, ISO weekday). The same as + ``self.date().isocalendar()``. + + +.. method:: datetime.isoformat([sep]) + + Return a string representing the date and time in ISO 8601 format, + YYYY-MM-DDTHH:MM:SS.mmmmmm or, if :attr:`microsecond` is 0, + YYYY-MM-DDTHH:MM:SS + + If :meth:`utcoffset` does not return ``None``, a 6-character string is + appended, giving the UTC offset in (signed) hours and minutes: + YYYY-MM-DDTHH:MM:SS.mmmmmm+HH:MM or, if :attr:`microsecond` is 0 + YYYY-MM-DDTHH:MM:SS+HH:MM + + The optional argument *sep* (default ``'T'``) is a one-character separator, + placed between the date and time portions of the result. For example, :: + + >>> from datetime import tzinfo, timedelta, datetime + >>> class TZ(tzinfo): + ... def utcoffset(self, dt): return timedelta(minutes=-399) + ... + >>> datetime(2002, 12, 25, tzinfo=TZ()).isoformat(' ') + '2002-12-25 00:00:00-06:39' + + +.. method:: datetime.__str__() + + For a :class:`datetime` instance *d*, ``str(d)`` is equivalent to + ``d.isoformat(' ')``. + + +.. method:: datetime.ctime() + + Return a string representing the date and time, for example ``datetime(2002, 12, + 4, 20, 30, 40).ctime() == 'Wed Dec 4 20:30:40 2002'``. ``d.ctime()`` is + equivalent to ``time.ctime(time.mktime(d.timetuple()))`` on platforms where the + native C :cfunc:`ctime` function (which :func:`time.ctime` invokes, but which + :meth:`datetime.ctime` does not invoke) conforms to the C standard. + + +.. method:: datetime.strftime(format) + + Return a string representing the date and time, controlled by an explicit format + string. See section :ref:`strftime-behavior`. + + +.. _datetime-time: + +:class:`time` Objects +--------------------- + +A time object represents a (local) time of day, independent of any particular +day, and subject to adjustment via a :class:`tzinfo` object. + + +.. class:: time(hour[, minute[, second[, microsecond[, tzinfo]]]]) + + All arguments are optional. *tzinfo* may be ``None``, or an instance of a + :class:`tzinfo` subclass. The remaining arguments may be ints or longs, in the + following ranges: + + * ``0 <= hour < 24`` + * ``0 <= minute < 60`` + * ``0 <= second < 60`` + * ``0 <= microsecond < 1000000``. + + If an argument outside those ranges is given, :exc:`ValueError` is raised. All + default to ``0`` except *tzinfo*, which defaults to :const:`None`. + +Class attributes: + + +.. attribute:: time.min + + The earliest representable :class:`time`, ``time(0, 0, 0, 0)``. + + +.. attribute:: time.max + + The latest representable :class:`time`, ``time(23, 59, 59, 999999)``. + + +.. attribute:: time.resolution + + The smallest possible difference between non-equal :class:`time` objects, + ``timedelta(microseconds=1)``, although note that arithmetic on :class:`time` + objects is not supported. + +Instance attributes (read-only): + + +.. attribute:: time.hour + + In ``range(24)``. + + +.. attribute:: time.minute + + In ``range(60)``. + + +.. attribute:: time.second + + In ``range(60)``. + + +.. attribute:: time.microsecond + + In ``range(1000000)``. + + +.. attribute:: time.tzinfo + + The object passed as the tzinfo argument to the :class:`time` constructor, or + ``None`` if none was passed. + +Supported operations: + +* comparison of :class:`time` to :class:`time`, where *a* is considered less + than *b* when *a* precedes *b* in time. If one comparand is naive and the other + is aware, :exc:`TypeError` is raised. If both comparands are aware, and have + the same :attr:`tzinfo` member, the common :attr:`tzinfo` member is ignored and + the base times are compared. If both comparands are aware and have different + :attr:`tzinfo` members, the comparands are first adjusted by subtracting their + UTC offsets (obtained from ``self.utcoffset()``). In order to stop mixed-type + comparisons from falling back to the default comparison by object address, when + a :class:`time` object is compared to an object of a different type, + :exc:`TypeError` is raised unless the comparison is ``==`` or ``!=``. The + latter cases return :const:`False` or :const:`True`, respectively. + +* hash, use as dict key + +* efficient pickling + +* in Boolean contexts, a :class:`time` object is considered to be true if and + only if, after converting it to minutes and subtracting :meth:`utcoffset` (or + ``0`` if that's ``None``), the result is non-zero. + +Instance methods: + + +.. method:: time.replace([hour[, minute[, second[, microsecond[, tzinfo]]]]]) + + Return a :class:`time` with the same value, except for those members given new + values by whichever keyword arguments are specified. Note that ``tzinfo=None`` + can be specified to create a naive :class:`time` from an aware :class:`time`, + without conversion of the time members. + + +.. method:: time.isoformat() + + Return a string representing the time in ISO 8601 format, HH:MM:SS.mmmmmm or, if + self.microsecond is 0, HH:MM:SS If :meth:`utcoffset` does not return ``None``, a + 6-character string is appended, giving the UTC offset in (signed) hours and + minutes: HH:MM:SS.mmmmmm+HH:MM or, if self.microsecond is 0, HH:MM:SS+HH:MM + + +.. method:: time.__str__() + + For a time *t*, ``str(t)`` is equivalent to ``t.isoformat()``. + + +.. method:: time.strftime(format) + + Return a string representing the time, controlled by an explicit format string. + See section :ref:`strftime-behavior`. + + +.. method:: time.utcoffset() + + If :attr:`tzinfo` is ``None``, returns ``None``, else returns + ``self.tzinfo.utcoffset(None)``, and raises an exception if the latter doesn't + return ``None`` or a :class:`timedelta` object representing a whole number of + minutes with magnitude less than one day. + + +.. method:: time.dst() + + If :attr:`tzinfo` is ``None``, returns ``None``, else returns + ``self.tzinfo.dst(None)``, and raises an exception if the latter doesn't return + ``None``, or a :class:`timedelta` object representing a whole number of minutes + with magnitude less than one day. + + +.. method:: time.tzname() + + If :attr:`tzinfo` is ``None``, returns ``None``, else returns + ``self.tzinfo.tzname(None)``, or raises an exception if the latter doesn't + return ``None`` or a string object. + + +.. _datetime-tzinfo: + +:class:`tzinfo` Objects +----------------------- + +:class:`tzinfo` is an abstract base clase, meaning that this class should not be +instantiated directly. You need to derive a concrete subclass, and (at least) +supply implementations of the standard :class:`tzinfo` methods needed by the +:class:`datetime` methods you use. The :mod:`datetime` module does not supply +any concrete subclasses of :class:`tzinfo`. + +An instance of (a concrete subclass of) :class:`tzinfo` can be passed to the +constructors for :class:`datetime` and :class:`time` objects. The latter objects +view their members as being in local time, and the :class:`tzinfo` object +supports methods revealing offset of local time from UTC, the name of the time +zone, and DST offset, all relative to a date or time object passed to them. + +Special requirement for pickling: A :class:`tzinfo` subclass must have an +:meth:`__init__` method that can be called with no arguments, else it can be +pickled but possibly not unpickled again. This is a technical requirement that +may be relaxed in the future. + +A concrete subclass of :class:`tzinfo` may need to implement the following +methods. Exactly which methods are needed depends on the uses made of aware +:mod:`datetime` objects. If in doubt, simply implement all of them. + + +.. method:: tzinfo.utcoffset(self, dt) + + Return offset of local time from UTC, in minutes east of UTC. If local time is + west of UTC, this should be negative. Note that this is intended to be the + total offset from UTC; for example, if a :class:`tzinfo` object represents both + time zone and DST adjustments, :meth:`utcoffset` should return their sum. If + the UTC offset isn't known, return ``None``. Else the value returned must be a + :class:`timedelta` object specifying a whole number of minutes in the range + -1439 to 1439 inclusive (1440 = 24\*60; the magnitude of the offset must be less + than one day). Most implementations of :meth:`utcoffset` will probably look + like one of these two:: + + return CONSTANT # fixed-offset class + return CONSTANT + self.dst(dt) # daylight-aware class + + If :meth:`utcoffset` does not return ``None``, :meth:`dst` should not return + ``None`` either. + + The default implementation of :meth:`utcoffset` raises + :exc:`NotImplementedError`. + + +.. method:: tzinfo.dst(self, dt) + + Return the daylight saving time (DST) adjustment, in minutes east of UTC, or + ``None`` if DST information isn't known. Return ``timedelta(0)`` if DST is not + in effect. If DST is in effect, return the offset as a :class:`timedelta` object + (see :meth:`utcoffset` for details). Note that DST offset, if applicable, has + already been added to the UTC offset returned by :meth:`utcoffset`, so there's + no need to consult :meth:`dst` unless you're interested in obtaining DST info + separately. For example, :meth:`datetime.timetuple` calls its :attr:`tzinfo` + member's :meth:`dst` method to determine how the :attr:`tm_isdst` flag should be + set, and :meth:`tzinfo.fromutc` calls :meth:`dst` to account for DST changes + when crossing time zones. + + An instance *tz* of a :class:`tzinfo` subclass that models both standard and + daylight times must be consistent in this sense: + + ``tz.utcoffset(dt) - tz.dst(dt)`` + + must return the same result for every :class:`datetime` *dt* with ``dt.tzinfo == + tz`` For sane :class:`tzinfo` subclasses, this expression yields the time + zone's "standard offset", which should not depend on the date or the time, but + only on geographic location. The implementation of :meth:`datetime.astimezone` + relies on this, but cannot detect violations; it's the programmer's + responsibility to ensure it. If a :class:`tzinfo` subclass cannot guarantee + this, it may be able to override the default implementation of + :meth:`tzinfo.fromutc` to work correctly with :meth:`astimezone` regardless. + + Most implementations of :meth:`dst` will probably look like one of these two:: + + def dst(self): + # a fixed-offset class: doesn't account for DST + return timedelta(0) + + or :: + + def dst(self): + # Code to set dston and dstoff to the time zone's DST + # transition times based on the input dt.year, and expressed + # in standard local time. Then + + if dston <= dt.replace(tzinfo=None) < dstoff: + return timedelta(hours=1) + else: + return timedelta(0) + + The default implementation of :meth:`dst` raises :exc:`NotImplementedError`. + + +.. method:: tzinfo.tzname(self, dt) + + Return the time zone name corresponding to the :class:`datetime` object *dt*, as + a string. Nothing about string names is defined by the :mod:`datetime` module, + and there's no requirement that it mean anything in particular. For example, + "GMT", "UTC", "-500", "-5:00", "EDT", "US/Eastern", "America/New York" are all + valid replies. Return ``None`` if a string name isn't known. Note that this is + a method rather than a fixed string primarily because some :class:`tzinfo` + subclasses will wish to return different names depending on the specific value + of *dt* passed, especially if the :class:`tzinfo` class is accounting for + daylight time. + + The default implementation of :meth:`tzname` raises :exc:`NotImplementedError`. + +These methods are called by a :class:`datetime` or :class:`time` object, in +response to their methods of the same names. A :class:`datetime` object passes +itself as the argument, and a :class:`time` object passes ``None`` as the +argument. A :class:`tzinfo` subclass's methods should therefore be prepared to +accept a *dt* argument of ``None``, or of class :class:`datetime`. + +When ``None`` is passed, it's up to the class designer to decide the best +response. For example, returning ``None`` is appropriate if the class wishes to +say that time objects don't participate in the :class:`tzinfo` protocols. It +may be more useful for ``utcoffset(None)`` to return the standard UTC offset, as +there is no other convention for discovering the standard offset. + +When a :class:`datetime` object is passed in response to a :class:`datetime` +method, ``dt.tzinfo`` is the same object as *self*. :class:`tzinfo` methods can +rely on this, unless user code calls :class:`tzinfo` methods directly. The +intent is that the :class:`tzinfo` methods interpret *dt* as being in local +time, and not need worry about objects in other timezones. + +There is one more :class:`tzinfo` method that a subclass may wish to override: + + +.. method:: tzinfo.fromutc(self, dt) + + This is called from the default :class:`datetime.astimezone()` implementation. + When called from that, ``dt.tzinfo`` is *self*, and *dt*'s date and time members + are to be viewed as expressing a UTC time. The purpose of :meth:`fromutc` is to + adjust the date and time members, returning an equivalent datetime in *self*'s + local time. + + Most :class:`tzinfo` subclasses should be able to inherit the default + :meth:`fromutc` implementation without problems. It's strong enough to handle + fixed-offset time zones, and time zones accounting for both standard and + daylight time, and the latter even if the DST transition times differ in + different years. An example of a time zone the default :meth:`fromutc` + implementation may not handle correctly in all cases is one where the standard + offset (from UTC) depends on the specific date and time passed, which can happen + for political reasons. The default implementations of :meth:`astimezone` and + :meth:`fromutc` may not produce the result you want if the result is one of the + hours straddling the moment the standard offset changes. + + Skipping code for error cases, the default :meth:`fromutc` implementation acts + like:: + + def fromutc(self, dt): + # raise ValueError error if dt.tzinfo is not self + dtoff = dt.utcoffset() + dtdst = dt.dst() + # raise ValueError if dtoff is None or dtdst is None + delta = dtoff - dtdst # this is self's standard offset + if delta: + dt += delta # convert to standard local time + dtdst = dt.dst() + # raise ValueError if dtdst is None + if dtdst: + return dt + dtdst + else: + return dt + +Example :class:`tzinfo` classes: + +.. literalinclude:: ../includes/tzinfo-examples.py + + +Note that there are unavoidable subtleties twice per year in a :class:`tzinfo` +subclass accounting for both standard and daylight time, at the DST transition +points. For concreteness, consider US Eastern (UTC -0500), where EDT begins the +minute after 1:59 (EST) on the first Sunday in April, and ends the minute after +1:59 (EDT) on the last Sunday in October:: + + UTC 3:MM 4:MM 5:MM 6:MM 7:MM 8:MM + EST 22:MM 23:MM 0:MM 1:MM 2:MM 3:MM + EDT 23:MM 0:MM 1:MM 2:MM 3:MM 4:MM + + start 22:MM 23:MM 0:MM 1:MM 3:MM 4:MM + + end 23:MM 0:MM 1:MM 1:MM 2:MM 3:MM + +When DST starts (the "start" line), the local wall clock leaps from 1:59 to +3:00. A wall time of the form 2:MM doesn't really make sense on that day, so +``astimezone(Eastern)`` won't deliver a result with ``hour == 2`` on the day DST +begins. In order for :meth:`astimezone` to make this guarantee, the +:meth:`rzinfo.dst` method must consider times in the "missing hour" (2:MM for +Eastern) to be in daylight time. + +When DST ends (the "end" line), there's a potentially worse problem: there's an +hour that can't be spelled unambiguously in local wall time: the last hour of +daylight time. In Eastern, that's times of the form 5:MM UTC on the day +daylight time ends. The local wall clock leaps from 1:59 (daylight time) back +to 1:00 (standard time) again. Local times of the form 1:MM are ambiguous. +:meth:`astimezone` mimics the local clock's behavior by mapping two adjacent UTC +hours into the same local hour then. In the Eastern example, UTC times of the +form 5:MM and 6:MM both map to 1:MM when converted to Eastern. In order for +:meth:`astimezone` to make this guarantee, the :meth:`tzinfo.dst` method must +consider times in the "repeated hour" to be in standard time. This is easily +arranged, as in the example, by expressing DST switch times in the time zone's +standard local time. + +Applications that can't bear such ambiguities should avoid using hybrid +:class:`tzinfo` subclasses; there are no ambiguities when using UTC, or any +other fixed-offset :class:`tzinfo` subclass (such as a class representing only +EST (fixed offset -5 hours), or only EDT (fixed offset -4 hours)). + + +.. _strftime-behavior: + +:meth:`strftime` Behavior +------------------------- + +:class:`date`, :class:`datetime`, and :class:`time` objects all support a +``strftime(format)`` method, to create a string representing the time under the +control of an explicit format string. Broadly speaking, ``d.strftime(fmt)`` +acts like the :mod:`time` module's ``time.strftime(fmt, d.timetuple())`` +although not all objects support a :meth:`timetuple` method. + +For :class:`time` objects, the format codes for year, month, and day should not +be used, as time objects have no such values. If they're used anyway, ``1900`` +is substituted for the year, and ``0`` for the month and day. + +For :class:`date` objects, the format codes for hours, minutes, and seconds +should not be used, as :class:`date` objects have no such values. If they're +used anyway, ``0`` is substituted for them. + +For a naive object, the ``%z`` and ``%Z`` format codes are replaced by empty +strings. + +For an aware object: + +``%z`` + :meth:`utcoffset` is transformed into a 5-character string of the form +HHMM or + -HHMM, where HH is a 2-digit string giving the number of UTC offset hours, and + MM is a 2-digit string giving the number of UTC offset minutes. For example, if + :meth:`utcoffset` returns ``timedelta(hours=-3, minutes=-30)``, ``%z`` is + replaced with the string ``'-0330'``. + +``%Z`` + If :meth:`tzname` returns ``None``, ``%Z`` is replaced by an empty string. + Otherwise ``%Z`` is replaced by the returned value, which must be a string. + +The full set of format codes supported varies across platforms, because Python +calls the platform C library's :func:`strftime` function, and platform +variations are common. The documentation for Python's :mod:`time` module lists +the format codes that the C standard (1989 version) requires, and those work on +all platforms with a standard C implementation. Note that the 1999 version of +the C standard added additional format codes. + +The exact range of years for which :meth:`strftime` works also varies across +platforms. Regardless of platform, years before 1900 cannot be used. + +.. % %% This example is obsolete, since strptime is now supported by datetime. +.. % +.. % \subsection{Examples} +.. % +.. % \subsubsection{Creating Datetime Objects from Formatted Strings} +.. % +.. % The \class{datetime} class does not directly support parsing formatted time +.. % strings. You can use \function{time.strptime} to do the parsing and create +.. % a \class{datetime} object from the tuple it returns: +.. % +.. % \begin{verbatim} +.. % >>> s = "2005-12-06T12:13:14" +.. % >>> from datetime import datetime +.. % >>> from time import strptime +.. % >>> datetime(*strptime(s, "%Y-%m-%dT%H:%M:%S")[0:6]) +.. % datetime.datetime(2005, 12, 6, 12, 13, 14) +.. % \end{verbatim} +.. % + diff --git a/Doc/library/dbhash.rst b/Doc/library/dbhash.rst new file mode 100644 index 0000000..b5c9590 --- /dev/null +++ b/Doc/library/dbhash.rst @@ -0,0 +1,114 @@ + +:mod:`dbhash` --- DBM-style interface to the BSD database library +================================================================= + +.. module:: dbhash + :synopsis: DBM-style interface to the BSD database library. +.. sectionauthor:: Fred L. Drake, Jr. + + +.. index:: module: bsddb + +The :mod:`dbhash` module provides a function to open databases using the BSD +``db`` library. This module mirrors the interface of the other Python database +modules that provide access to DBM-style databases. The :mod:`bsddb` module is +required to use :mod:`dbhash`. + +This module provides an exception and a function: + + +.. exception:: error + + Exception raised on database errors other than :exc:`KeyError`. It is a synonym + for :exc:`bsddb.error`. + + +.. function:: open(path[, flag[, mode]]) + + Open a ``db`` database and return the database object. The *path* argument is + the name of the database file. + + The *flag* argument can be: + + +---------+-------------------------------------------+ + | Value | Meaning | + +=========+===========================================+ + | ``'r'`` | Open existing database for reading only | + | | (default) | + +---------+-------------------------------------------+ + | ``'w'`` | Open existing database for reading and | + | | writing | + +---------+-------------------------------------------+ + | ``'c'`` | Open database for reading and writing, | + | | creating it if it doesn't exist | + +---------+-------------------------------------------+ + | ``'n'`` | Always create a new, empty database, open | + | | for reading and writing | + +---------+-------------------------------------------+ + + For platforms on which the BSD ``db`` library supports locking, an ``'l'`` + can be appended to indicate that locking should be used. + + The optional *mode* parameter is used to indicate the Unix permission bits that + should be set if a new database must be created; this will be masked by the + current umask value for the process. + + +.. seealso:: + + Module :mod:`anydbm` + Generic interface to ``dbm``\ -style databases. + + Module :mod:`bsddb` + Lower-level interface to the BSD ``db`` library. + + Module :mod:`whichdb` + Utility module used to determine the type of an existing database. + + +.. _dbhash-objects: + +Database Objects +---------------- + +The database objects returned by :func:`open` provide the methods common to all +the DBM-style databases and mapping objects. The following methods are +available in addition to the standard methods. + + +.. method:: dbhash.first() + + It's possible to loop over every key/value pair in the database using this + method and the :meth:`next` method. The traversal is ordered by the databases + internal hash values, and won't be sorted by the key values. This method + returns the starting key. + + +.. method:: dbhash.last() + + Return the last key/value pair in a database traversal. This may be used to + begin a reverse-order traversal; see :meth:`previous`. + + +.. method:: dbhash.next() + + Returns the key next key/value pair in a database traversal. The following code + prints every key in the database ``db``, without having to create a list in + memory that contains them all:: + + print db.first() + for i in range(1, len(db)): + print db.next() + + +.. method:: dbhash.previous() + + Returns the previous key/value pair in a forward-traversal of the database. In + conjunction with :meth:`last`, this may be used to implement a reverse-order + traversal. + + +.. method:: dbhash.sync() + + This method forces any unwritten data to be written to the disk. + diff --git a/Doc/library/dbm.rst b/Doc/library/dbm.rst new file mode 100644 index 0000000..52923e8 --- /dev/null +++ b/Doc/library/dbm.rst @@ -0,0 +1,74 @@ + +:mod:`dbm` --- Simple "database" interface +========================================== + +.. module:: dbm + :platform: Unix + :synopsis: The standard "database" interface, based on ndbm. + + +The :mod:`dbm` module provides an interface to the Unix "(n)dbm" library. Dbm +objects behave like mappings (dictionaries), except that keys and values are +always strings. Printing a dbm object doesn't print the keys and values, and the +:meth:`items` and :meth:`values` methods are not supported. + +This module can be used with the "classic" ndbm interface, the BSD DB +compatibility interface, or the GNU GDBM compatibility interface. On Unix, the +:program:`configure` script will attempt to locate the appropriate header file +to simplify building this module. + +The module defines the following: + + +.. exception:: error + + Raised on dbm-specific errors, such as I/O errors. :exc:`KeyError` is raised for + general mapping errors like specifying an incorrect key. + + +.. data:: library + + Name of the ``ndbm`` implementation library used. + + +.. function:: open(filename[, flag[, mode]]) + + Open a dbm database and return a dbm object. The *filename* argument is the + name of the database file (without the :file:`.dir` or :file:`.pag` extensions; + note that the BSD DB implementation of the interface will append the extension + :file:`.db` and only create one file). + + The optional *flag* argument must be one of these values: + + +---------+-------------------------------------------+ + | Value | Meaning | + +=========+===========================================+ + | ``'r'`` | Open existing database for reading only | + | | (default) | + +---------+-------------------------------------------+ + | ``'w'`` | Open existing database for reading and | + | | writing | + +---------+-------------------------------------------+ + | ``'c'`` | Open database for reading and writing, | + | | creating it if it doesn't exist | + +---------+-------------------------------------------+ + | ``'n'`` | Always create a new, empty database, open | + | | for reading and writing | + +---------+-------------------------------------------+ + + The optional *mode* argument is the Unix mode of the file, used only when the + database has to be created. It defaults to octal ``0666`` (and will be + modified by the prevailing umask). + + +.. seealso:: + + Module :mod:`anydbm` + Generic interface to ``dbm``\ -style databases. + + Module :mod:`gdbm` + Similar interface to the GNU GDBM library. + + Module :mod:`whichdb` + Utility module used to determine the type of an existing database. + diff --git a/Doc/library/decimal.rst b/Doc/library/decimal.rst new file mode 100644 index 0000000..1d17109 --- /dev/null +++ b/Doc/library/decimal.rst @@ -0,0 +1,1289 @@ + +:mod:`decimal` --- Decimal floating point arithmetic +==================================================== + +.. module:: decimal + :synopsis: Implementation of the General Decimal Arithmetic Specification. + + +.. moduleauthor:: Eric Price +.. moduleauthor:: Facundo Batista +.. moduleauthor:: Raymond Hettinger +.. moduleauthor:: Aahz +.. moduleauthor:: Tim Peters + + +.. sectionauthor:: Raymond D. Hettinger + + +.. versionadded:: 2.4 + +The :mod:`decimal` module provides support for decimal floating point +arithmetic. It offers several advantages over the :class:`float()` datatype: + +* Decimal numbers can be represented exactly. In contrast, numbers like + :const:`1.1` do not have an exact representation in binary floating point. End + users typically would not expect :const:`1.1` to display as + :const:`1.1000000000000001` as it does with binary floating point. + +* The exactness carries over into arithmetic. In decimal floating point, ``0.1 + + 0.1 + 0.1 - 0.3`` is exactly equal to zero. In binary floating point, result + is :const:`5.5511151231257827e-017`. While near to zero, the differences + prevent reliable equality testing and differences can accumulate. For this + reason, decimal would be preferred in accounting applications which have strict + equality invariants. + +* The decimal module incorporates a notion of significant places so that ``1.30 + + 1.20`` is :const:`2.50`. The trailing zero is kept to indicate significance. + This is the customary presentation for monetary applications. For + multiplication, the "schoolbook" approach uses all the figures in the + multiplicands. For instance, ``1.3 * 1.2`` gives :const:`1.56` while ``1.30 * + 1.20`` gives :const:`1.5600`. + +* Unlike hardware based binary floating point, the decimal module has a user + settable precision (defaulting to 28 places) which can be as large as needed for + a given problem:: + + >>> getcontext().prec = 6 + >>> Decimal(1) / Decimal(7) + Decimal("0.142857") + >>> getcontext().prec = 28 + >>> Decimal(1) / Decimal(7) + Decimal("0.1428571428571428571428571429") + +* Both binary and decimal floating point are implemented in terms of published + standards. While the built-in float type exposes only a modest portion of its + capabilities, the decimal module exposes all required parts of the standard. + When needed, the programmer has full control over rounding and signal handling. + +The module design is centered around three concepts: the decimal number, the +context for arithmetic, and signals. + +A decimal number is immutable. It has a sign, coefficient digits, and an +exponent. To preserve significance, the coefficient digits do not truncate +trailing zeroes. Decimals also include special values such as +:const:`Infinity`, :const:`-Infinity`, and :const:`NaN`. The standard also +differentiates :const:`-0` from :const:`+0`. + +The context for arithmetic is an environment specifying precision, rounding +rules, limits on exponents, flags indicating the results of operations, and trap +enablers which determine whether signals are treated as exceptions. Rounding +options include :const:`ROUND_CEILING`, :const:`ROUND_DOWN`, +:const:`ROUND_FLOOR`, :const:`ROUND_HALF_DOWN`, :const:`ROUND_HALF_EVEN`, +:const:`ROUND_HALF_UP`, and :const:`ROUND_UP`. + +Signals are groups of exceptional conditions arising during the course of +computation. Depending on the needs of the application, signals may be ignored, +considered as informational, or treated as exceptions. The signals in the +decimal module are: :const:`Clamped`, :const:`InvalidOperation`, +:const:`DivisionByZero`, :const:`Inexact`, :const:`Rounded`, :const:`Subnormal`, +:const:`Overflow`, and :const:`Underflow`. + +For each signal there is a flag and a trap enabler. When a signal is +encountered, its flag is incremented from zero and, then, if the trap enabler is +set to one, an exception is raised. Flags are sticky, so the user needs to +reset them before monitoring a calculation. + + +.. seealso:: + + IBM's General Decimal Arithmetic Specification, `The General Decimal Arithmetic + Specification `_. + + IEEE standard 854-1987, `Unofficial IEEE 854 Text + `_. + +.. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +.. _decimal-tutorial: + +Quick-start Tutorial +-------------------- + +The usual start to using decimals is importing the module, viewing the current +context with :func:`getcontext` and, if necessary, setting new values for +precision, rounding, or enabled traps:: + + >>> from decimal import * + >>> getcontext() + Context(prec=28, rounding=ROUND_HALF_EVEN, Emin=-999999999, Emax=999999999, + capitals=1, flags=[], traps=[Overflow, InvalidOperation, + DivisionByZero]) + + >>> getcontext().prec = 7 # Set a new precision + +Decimal instances can be constructed from integers, strings, or tuples. To +create a Decimal from a :class:`float`, first convert it to a string. This +serves as an explicit reminder of the details of the conversion (including +representation error). Decimal numbers include special values such as +:const:`NaN` which stands for "Not a number", positive and negative +:const:`Infinity`, and :const:`-0`. :: + + >>> Decimal(10) + Decimal("10") + >>> Decimal("3.14") + Decimal("3.14") + >>> Decimal((0, (3, 1, 4), -2)) + Decimal("3.14") + >>> Decimal(str(2.0 ** 0.5)) + Decimal("1.41421356237") + >>> Decimal("NaN") + Decimal("NaN") + >>> Decimal("-Infinity") + Decimal("-Infinity") + +The significance of a new Decimal is determined solely by the number of digits +input. Context precision and rounding only come into play during arithmetic +operations. :: + + >>> getcontext().prec = 6 + >>> Decimal('3.0') + Decimal("3.0") + >>> Decimal('3.1415926535') + Decimal("3.1415926535") + >>> Decimal('3.1415926535') + Decimal('2.7182818285') + Decimal("5.85987") + >>> getcontext().rounding = ROUND_UP + >>> Decimal('3.1415926535') + Decimal('2.7182818285') + Decimal("5.85988") + +Decimals interact well with much of the rest of Python. Here is a small decimal +floating point flying circus:: + + >>> data = map(Decimal, '1.34 1.87 3.45 2.35 1.00 0.03 9.25'.split()) + >>> max(data) + Decimal("9.25") + >>> min(data) + Decimal("0.03") + >>> sorted(data) + [Decimal("0.03"), Decimal("1.00"), Decimal("1.34"), Decimal("1.87"), + Decimal("2.35"), Decimal("3.45"), Decimal("9.25")] + >>> sum(data) + Decimal("19.29") + >>> a,b,c = data[:3] + >>> str(a) + '1.34' + >>> float(a) + 1.3400000000000001 + >>> round(a, 1) # round() first converts to binary floating point + 1.3 + >>> int(a) + 1 + >>> a * 5 + Decimal("6.70") + >>> a * b + Decimal("2.5058") + >>> c % a + Decimal("0.77") + +The :meth:`quantize` method rounds a number to a fixed exponent. This method is +useful for monetary applications that often round results to a fixed number of +places:: + + >>> Decimal('7.325').quantize(Decimal('.01'), rounding=ROUND_DOWN) + Decimal("7.32") + >>> Decimal('7.325').quantize(Decimal('1.'), rounding=ROUND_UP) + Decimal("8") + +As shown above, the :func:`getcontext` function accesses the current context and +allows the settings to be changed. This approach meets the needs of most +applications. + +For more advanced work, it may be useful to create alternate contexts using the +Context() constructor. To make an alternate active, use the :func:`setcontext` +function. + +In accordance with the standard, the :mod:`Decimal` module provides two ready to +use standard contexts, :const:`BasicContext` and :const:`ExtendedContext`. The +former is especially useful for debugging because many of the traps are +enabled:: + + >>> myothercontext = Context(prec=60, rounding=ROUND_HALF_DOWN) + >>> setcontext(myothercontext) + >>> Decimal(1) / Decimal(7) + Decimal("0.142857142857142857142857142857142857142857142857142857142857") + + >>> ExtendedContext + Context(prec=9, rounding=ROUND_HALF_EVEN, Emin=-999999999, Emax=999999999, + capitals=1, flags=[], traps=[]) + >>> setcontext(ExtendedContext) + >>> Decimal(1) / Decimal(7) + Decimal("0.142857143") + >>> Decimal(42) / Decimal(0) + Decimal("Infinity") + + >>> setcontext(BasicContext) + >>> Decimal(42) / Decimal(0) + Traceback (most recent call last): + File "", line 1, in -toplevel- + Decimal(42) / Decimal(0) + DivisionByZero: x / 0 + +Contexts also have signal flags for monitoring exceptional conditions +encountered during computations. The flags remain set until explicitly cleared, +so it is best to clear the flags before each set of monitored computations by +using the :meth:`clear_flags` method. :: + + >>> setcontext(ExtendedContext) + >>> getcontext().clear_flags() + >>> Decimal(355) / Decimal(113) + Decimal("3.14159292") + >>> getcontext() + Context(prec=9, rounding=ROUND_HALF_EVEN, Emin=-999999999, Emax=999999999, + capitals=1, flags=[Inexact, Rounded], traps=[]) + +The *flags* entry shows that the rational approximation to :const:`Pi` was +rounded (digits beyond the context precision were thrown away) and that the +result is inexact (some of the discarded digits were non-zero). + +Individual traps are set using the dictionary in the :attr:`traps` field of a +context:: + + >>> Decimal(1) / Decimal(0) + Decimal("Infinity") + >>> getcontext().traps[DivisionByZero] = 1 + >>> Decimal(1) / Decimal(0) + Traceback (most recent call last): + File "", line 1, in -toplevel- + Decimal(1) / Decimal(0) + DivisionByZero: x / 0 + +Most programs adjust the current context only once, at the beginning of the +program. And, in many applications, data is converted to :class:`Decimal` with +a single cast inside a loop. With context set and decimals created, the bulk of +the program manipulates the data no differently than with other Python numeric +types. + +.. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +.. _decimal-decimal: + +Decimal objects +--------------- + + +.. class:: Decimal([value [, context]]) + + Constructs a new :class:`Decimal` object based from *value*. + + *value* can be an integer, string, tuple, or another :class:`Decimal` object. If + no *value* is given, returns ``Decimal("0")``. If *value* is a string, it + should conform to the decimal numeric string syntax:: + + sign ::= '+' | '-' + digit ::= '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' + indicator ::= 'e' | 'E' + digits ::= digit [digit]... + decimal-part ::= digits '.' [digits] | ['.'] digits + exponent-part ::= indicator [sign] digits + infinity ::= 'Infinity' | 'Inf' + nan ::= 'NaN' [digits] | 'sNaN' [digits] + numeric-value ::= decimal-part [exponent-part] | infinity + numeric-string ::= [sign] numeric-value | [sign] nan + + If *value* is a :class:`tuple`, it should have three components, a sign + (:const:`0` for positive or :const:`1` for negative), a :class:`tuple` of + digits, and an integer exponent. For example, ``Decimal((0, (1, 4, 1, 4), -3))`` + returns ``Decimal("1.414")``. + + The *context* precision does not affect how many digits are stored. That is + determined exclusively by the number of digits in *value*. For example, + ``Decimal("3.00000")`` records all five zeroes even if the context precision is + only three. + + The purpose of the *context* argument is determining what to do if *value* is a + malformed string. If the context traps :const:`InvalidOperation`, an exception + is raised; otherwise, the constructor returns a new Decimal with the value of + :const:`NaN`. + + Once constructed, :class:`Decimal` objects are immutable. + +Decimal floating point objects share many properties with the other builtin +numeric types such as :class:`float` and :class:`int`. All of the usual math +operations and special methods apply. Likewise, decimal objects can be copied, +pickled, printed, used as dictionary keys, used as set elements, compared, +sorted, and coerced to another type (such as :class:`float` or :class:`long`). + +In addition to the standard numeric properties, decimal floating point objects +also have a number of specialized methods: + + +.. method:: Decimal.adjusted() + + Return the adjusted exponent after shifting out the coefficient's rightmost + digits until only the lead digit remains: ``Decimal("321e+5").adjusted()`` + returns seven. Used for determining the position of the most significant digit + with respect to the decimal point. + + +.. method:: Decimal.as_tuple() + + Returns a tuple representation of the number: ``(sign, digittuple, exponent)``. + + +.. method:: Decimal.compare(other[, context]) + + Compares like :meth:`__cmp__` but returns a decimal instance:: + + a or b is a NaN ==> Decimal("NaN") + a < b ==> Decimal("-1") + a == b ==> Decimal("0") + a > b ==> Decimal("1") + + +.. method:: Decimal.max(other[, context]) + + Like ``max(self, other)`` except that the context rounding rule is applied + before returning and that :const:`NaN` values are either signalled or ignored + (depending on the context and whether they are signaling or quiet). + + +.. method:: Decimal.min(other[, context]) + + Like ``min(self, other)`` except that the context rounding rule is applied + before returning and that :const:`NaN` values are either signalled or ignored + (depending on the context and whether they are signaling or quiet). + + +.. method:: Decimal.normalize([context]) + + Normalize the number by stripping the rightmost trailing zeroes and converting + any result equal to :const:`Decimal("0")` to :const:`Decimal("0e0")`. Used for + producing canonical values for members of an equivalence class. For example, + ``Decimal("32.100")`` and ``Decimal("0.321000e+2")`` both normalize to the + equivalent value ``Decimal("32.1")``. + + +.. method:: Decimal.quantize(exp [, rounding[, context[, watchexp]]]) + + Quantize makes the exponent the same as *exp*. Searches for a rounding method + in *rounding*, then in *context*, and then in the current context. + + If *watchexp* is set (default), then an error is returned whenever the resulting + exponent is greater than :attr:`Emax` or less than :attr:`Etiny`. + + +.. method:: Decimal.remainder_near(other[, context]) + + Computes the modulo as either a positive or negative value depending on which is + closest to zero. For instance, ``Decimal(10).remainder_near(6)`` returns + ``Decimal("-2")`` which is closer to zero than ``Decimal("4")``. + + If both are equally close, the one chosen will have the same sign as *self*. + + +.. method:: Decimal.same_quantum(other[, context]) + + Test whether self and other have the same exponent or whether both are + :const:`NaN`. + + +.. method:: Decimal.sqrt([context]) + + Return the square root to full precision. + + +.. method:: Decimal.to_eng_string([context]) + + Convert to an engineering-type string. + + Engineering notation has an exponent which is a multiple of 3, so there are up + to 3 digits left of the decimal place. For example, converts + ``Decimal('123E+1')`` to ``Decimal("1.23E+3")`` + + +.. method:: Decimal.to_integral([rounding[, context]]) + + Rounds to the nearest integer without signaling :const:`Inexact` or + :const:`Rounded`. If given, applies *rounding*; otherwise, uses the rounding + method in either the supplied *context* or the current context. + +.. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +.. _decimal-context: + +Context objects +--------------- + +Contexts are environments for arithmetic operations. They govern precision, set +rules for rounding, determine which signals are treated as exceptions, and limit +the range for exponents. + +Each thread has its own current context which is accessed or changed using the +:func:`getcontext` and :func:`setcontext` functions: + + +.. function:: getcontext() + + Return the current context for the active thread. + + +.. function:: setcontext(c) + + Set the current context for the active thread to *c*. + +Beginning with Python 2.5, you can also use the :keyword:`with` statement and +the :func:`localcontext` function to temporarily change the active context. + + +.. function:: localcontext([c]) + + Return a context manager that will set the current context for the active thread + to a copy of *c* on entry to the with-statement and restore the previous context + when exiting the with-statement. If no context is specified, a copy of the + current context is used. + + .. versionadded:: 2.5 + + For example, the following code sets the current decimal precision to 42 places, + performs a calculation, and then automatically restores the previous context:: + + from __future__ import with_statement + from decimal import localcontext + + with localcontext() as ctx: + ctx.prec = 42 # Perform a high precision calculation + s = calculate_something() + s = +s # Round the final result back to the default precision + +New contexts can also be created using the :class:`Context` constructor +described below. In addition, the module provides three pre-made contexts: + + +.. class:: BasicContext + + This is a standard context defined by the General Decimal Arithmetic + Specification. Precision is set to nine. Rounding is set to + :const:`ROUND_HALF_UP`. All flags are cleared. All traps are enabled (treated + as exceptions) except :const:`Inexact`, :const:`Rounded`, and + :const:`Subnormal`. + + Because many of the traps are enabled, this context is useful for debugging. + + +.. class:: ExtendedContext + + This is a standard context defined by the General Decimal Arithmetic + Specification. Precision is set to nine. Rounding is set to + :const:`ROUND_HALF_EVEN`. All flags are cleared. No traps are enabled (so that + exceptions are not raised during computations). + + Because the trapped are disabled, this context is useful for applications that + prefer to have result value of :const:`NaN` or :const:`Infinity` instead of + raising exceptions. This allows an application to complete a run in the + presence of conditions that would otherwise halt the program. + + +.. class:: DefaultContext + + This context is used by the :class:`Context` constructor as a prototype for new + contexts. Changing a field (such a precision) has the effect of changing the + default for new contexts creating by the :class:`Context` constructor. + + This context is most useful in multi-threaded environments. Changing one of the + fields before threads are started has the effect of setting system-wide + defaults. Changing the fields after threads have started is not recommended as + it would require thread synchronization to prevent race conditions. + + In single threaded environments, it is preferable to not use this context at + all. Instead, simply create contexts explicitly as described below. + + The default values are precision=28, rounding=ROUND_HALF_EVEN, and enabled traps + for Overflow, InvalidOperation, and DivisionByZero. + +In addition to the three supplied contexts, new contexts can be created with the +:class:`Context` constructor. + + +.. class:: Context(prec=None, rounding=None, traps=None, flags=None, Emin=None, Emax=None, capitals=1) + + Creates a new context. If a field is not specified or is :const:`None`, the + default values are copied from the :const:`DefaultContext`. If the *flags* + field is not specified or is :const:`None`, all flags are cleared. + + The *prec* field is a positive integer that sets the precision for arithmetic + operations in the context. + + The *rounding* option is one of: + + * :const:`ROUND_CEILING` (towards :const:`Infinity`), + * :const:`ROUND_DOWN` (towards zero), + * :const:`ROUND_FLOOR` (towards :const:`-Infinity`), + * :const:`ROUND_HALF_DOWN` (to nearest with ties going towards zero), + * :const:`ROUND_HALF_EVEN` (to nearest with ties going to nearest even integer), + * :const:`ROUND_HALF_UP` (to nearest with ties going away from zero), or + * :const:`ROUND_UP` (away from zero). + + The *traps* and *flags* fields list any signals to be set. Generally, new + contexts should only set traps and leave the flags clear. + + The *Emin* and *Emax* fields are integers specifying the outer limits allowable + for exponents. + + The *capitals* field is either :const:`0` or :const:`1` (the default). If set to + :const:`1`, exponents are printed with a capital :const:`E`; otherwise, a + lowercase :const:`e` is used: :const:`Decimal('6.02e+23')`. + +The :class:`Context` class defines several general purpose methods as well as a +large number of methods for doing arithmetic directly in a given context. + + +.. method:: Context.clear_flags() + + Resets all of the flags to :const:`0`. + + +.. method:: Context.copy() + + Return a duplicate of the context. + + +.. method:: Context.create_decimal(num) + + Creates a new Decimal instance from *num* but using *self* as context. Unlike + the :class:`Decimal` constructor, the context precision, rounding method, flags, + and traps are applied to the conversion. + + This is useful because constants are often given to a greater precision than is + needed by the application. Another benefit is that rounding immediately + eliminates unintended effects from digits beyond the current precision. In the + following example, using unrounded inputs means that adding zero to a sum can + change the result:: + + >>> getcontext().prec = 3 + >>> Decimal("3.4445") + Decimal("1.0023") + Decimal("4.45") + >>> Decimal("3.4445") + Decimal(0) + Decimal("1.0023") + Decimal("4.44") + + +.. method:: Context.Etiny() + + Returns a value equal to ``Emin - prec + 1`` which is the minimum exponent value + for subnormal results. When underflow occurs, the exponent is set to + :const:`Etiny`. + + +.. method:: Context.Etop() + + Returns a value equal to ``Emax - prec + 1``. + +The usual approach to working with decimals is to create :class:`Decimal` +instances and then apply arithmetic operations which take place within the +current context for the active thread. An alternate approach is to use context +methods for calculating within a specific context. The methods are similar to +those for the :class:`Decimal` class and are only briefly recounted here. + + +.. method:: Context.abs(x) + + Returns the absolute value of *x*. + + +.. method:: Context.add(x, y) + + Return the sum of *x* and *y*. + + +.. method:: Context.compare(x, y) + + Compares values numerically. + + Like :meth:`__cmp__` but returns a decimal instance:: + + a or b is a NaN ==> Decimal("NaN") + a < b ==> Decimal("-1") + a == b ==> Decimal("0") + a > b ==> Decimal("1") + + +.. method:: Context.divide(x, y) + + Return *x* divided by *y*. + + +.. method:: Context.divmod(x, y) + + Divides two numbers and returns the integer part of the result. + + +.. method:: Context.max(x, y) + + Compare two values numerically and return the maximum. + + If they are numerically equal then the left-hand operand is chosen as the + result. + + +.. method:: Context.min(x, y) + + Compare two values numerically and return the minimum. + + If they are numerically equal then the left-hand operand is chosen as the + result. + + +.. method:: Context.minus(x) + + Minus corresponds to the unary prefix minus operator in Python. + + +.. method:: Context.multiply(x, y) + + Return the product of *x* and *y*. + + +.. method:: Context.normalize(x) + + Normalize reduces an operand to its simplest form. + + Essentially a :meth:`plus` operation with all trailing zeros removed from the + result. + + +.. method:: Context.plus(x) + + Plus corresponds to the unary prefix plus operator in Python. This operation + applies the context precision and rounding, so it is *not* an identity + operation. + + +.. method:: Context.power(x, y[, modulo]) + + Return ``x ** y`` to the *modulo* if given. + + The right-hand operand must be a whole number whose integer part (after any + exponent has been applied) has no more than 9 digits and whose fractional part + (if any) is all zeros before any rounding. The operand may be positive, + negative, or zero; if negative, the absolute value of the power is used, and the + left-hand operand is inverted (divided into 1) before use. + + If the increased precision needed for the intermediate calculations exceeds the + capabilities of the implementation then an :const:`InvalidOperation` condition + is signaled. + + If, when raising to a negative power, an underflow occurs during the division + into 1, the operation is not halted at that point but continues. + + +.. method:: Context.quantize(x, y) + + Returns a value equal to *x* after rounding and having the exponent of *y*. + + Unlike other operations, if the length of the coefficient after the quantize + operation would be greater than precision, then an :const:`InvalidOperation` is + signaled. This guarantees that, unless there is an error condition, the + quantized exponent is always equal to that of the right-hand operand. + + Also unlike other operations, quantize never signals Underflow, even if the + result is subnormal and inexact. + + +.. method:: Context.remainder(x, y) + + Returns the remainder from integer division. + + The sign of the result, if non-zero, is the same as that of the original + dividend. + + +.. method:: Context.remainder_near(x, y) + + Computed the modulo as either a positive or negative value depending on which is + closest to zero. For instance, ``Decimal(10).remainder_near(6)`` returns + ``Decimal("-2")`` which is closer to zero than ``Decimal("4")``. + + If both are equally close, the one chosen will have the same sign as *self*. + + +.. method:: Context.same_quantum(x, y) + + Test whether *x* and *y* have the same exponent or whether both are + :const:`NaN`. + + +.. method:: Context.sqrt(x) + + Return the square root of *x* to full precision. + + +.. method:: Context.subtract(x, y) + + Return the difference between *x* and *y*. + + +.. method:: Context.to_eng_string() + + Convert to engineering-type string. + + Engineering notation has an exponent which is a multiple of 3, so there are up + to 3 digits left of the decimal place. For example, converts + ``Decimal('123E+1')`` to ``Decimal("1.23E+3")`` + + +.. method:: Context.to_integral(x) + + Rounds to the nearest integer without signaling :const:`Inexact` or + :const:`Rounded`. + + +.. method:: Context.to_sci_string(x) + + Converts a number to a string using scientific notation. + +.. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +.. _decimal-signals: + +Signals +------- + +Signals represent conditions that arise during computation. Each corresponds to +one context flag and one context trap enabler. + +The context flag is incremented whenever the condition is encountered. After the +computation, flags may be checked for informational purposes (for instance, to +determine whether a computation was exact). After checking the flags, be sure to +clear all flags before starting the next computation. + +If the context's trap enabler is set for the signal, then the condition causes a +Python exception to be raised. For example, if the :class:`DivisionByZero` trap +is set, then a :exc:`DivisionByZero` exception is raised upon encountering the +condition. + + +.. class:: Clamped + + Altered an exponent to fit representation constraints. + + Typically, clamping occurs when an exponent falls outside the context's + :attr:`Emin` and :attr:`Emax` limits. If possible, the exponent is reduced to + fit by adding zeroes to the coefficient. + + +.. class:: DecimalException + + Base class for other signals and a subclass of :exc:`ArithmeticError`. + + +.. class:: DivisionByZero + + Signals the division of a non-infinite number by zero. + + Can occur with division, modulo division, or when raising a number to a negative + power. If this signal is not trapped, returns :const:`Infinity` or + :const:`-Infinity` with the sign determined by the inputs to the calculation. + + +.. class:: Inexact + + Indicates that rounding occurred and the result is not exact. + + Signals when non-zero digits were discarded during rounding. The rounded result + is returned. The signal flag or trap is used to detect when results are + inexact. + + +.. class:: InvalidOperation + + An invalid operation was performed. + + Indicates that an operation was requested that does not make sense. If not + trapped, returns :const:`NaN`. Possible causes include:: + + Infinity - Infinity + 0 * Infinity + Infinity / Infinity + x % 0 + Infinity % x + x._rescale( non-integer ) + sqrt(-x) and x > 0 + 0 ** 0 + x ** (non-integer) + x ** Infinity + + +.. class:: Overflow + + Numerical overflow. + + Indicates the exponent is larger than :attr:`Emax` after rounding has occurred. + If not trapped, the result depends on the rounding mode, either pulling inward + to the largest representable finite number or rounding outward to + :const:`Infinity`. In either case, :class:`Inexact` and :class:`Rounded` are + also signaled. + + +.. class:: Rounded + + Rounding occurred though possibly no information was lost. + + Signaled whenever rounding discards digits; even if those digits are zero (such + as rounding :const:`5.00` to :const:`5.0`). If not trapped, returns the result + unchanged. This signal is used to detect loss of significant digits. + + +.. class:: Subnormal + + Exponent was lower than :attr:`Emin` prior to rounding. + + Occurs when an operation result is subnormal (the exponent is too small). If not + trapped, returns the result unchanged. + + +.. class:: Underflow + + Numerical underflow with result rounded to zero. + + Occurs when a subnormal result is pushed to zero by rounding. :class:`Inexact` + and :class:`Subnormal` are also signaled. + +The following table summarizes the hierarchy of signals:: + + exceptions.ArithmeticError(exceptions.Exception) + DecimalException + Clamped + DivisionByZero(DecimalException, exceptions.ZeroDivisionError) + Inexact + Overflow(Inexact, Rounded) + Underflow(Inexact, Rounded, Subnormal) + InvalidOperation + Rounded + Subnormal + +.. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +.. _decimal-notes: + +Floating Point Notes +-------------------- + + +Mitigating round-off error with increased precision +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The use of decimal floating point eliminates decimal representation error +(making it possible to represent :const:`0.1` exactly); however, some operations +can still incur round-off error when non-zero digits exceed the fixed precision. + +The effects of round-off error can be amplified by the addition or subtraction +of nearly offsetting quantities resulting in loss of significance. Knuth +provides two instructive examples where rounded floating point arithmetic with +insufficient precision causes the breakdown of the associative and distributive +properties of addition:: + + # Examples from Seminumerical Algorithms, Section 4.2.2. + >>> from decimal import Decimal, getcontext + >>> getcontext().prec = 8 + + >>> u, v, w = Decimal(11111113), Decimal(-11111111), Decimal('7.51111111') + >>> (u + v) + w + Decimal("9.5111111") + >>> u + (v + w) + Decimal("10") + + >>> u, v, w = Decimal(20000), Decimal(-6), Decimal('6.0000003') + >>> (u*v) + (u*w) + Decimal("0.01") + >>> u * (v+w) + Decimal("0.0060000") + +The :mod:`decimal` module makes it possible to restore the identities by +expanding the precision sufficiently to avoid loss of significance:: + + >>> getcontext().prec = 20 + >>> u, v, w = Decimal(11111113), Decimal(-11111111), Decimal('7.51111111') + >>> (u + v) + w + Decimal("9.51111111") + >>> u + (v + w) + Decimal("9.51111111") + >>> + >>> u, v, w = Decimal(20000), Decimal(-6), Decimal('6.0000003') + >>> (u*v) + (u*w) + Decimal("0.0060000") + >>> u * (v+w) + Decimal("0.0060000") + + +Special values +^^^^^^^^^^^^^^ + +The number system for the :mod:`decimal` module provides special values +including :const:`NaN`, :const:`sNaN`, :const:`-Infinity`, :const:`Infinity`, +and two zeroes, :const:`+0` and :const:`-0`. + +Infinities can be constructed directly with: ``Decimal('Infinity')``. Also, +they can arise from dividing by zero when the :exc:`DivisionByZero` signal is +not trapped. Likewise, when the :exc:`Overflow` signal is not trapped, infinity +can result from rounding beyond the limits of the largest representable number. + +The infinities are signed (affine) and can be used in arithmetic operations +where they get treated as very large, indeterminate numbers. For instance, +adding a constant to infinity gives another infinite result. + +Some operations are indeterminate and return :const:`NaN`, or if the +:exc:`InvalidOperation` signal is trapped, raise an exception. For example, +``0/0`` returns :const:`NaN` which means "not a number". This variety of +:const:`NaN` is quiet and, once created, will flow through other computations +always resulting in another :const:`NaN`. This behavior can be useful for a +series of computations that occasionally have missing inputs --- it allows the +calculation to proceed while flagging specific results as invalid. + +A variant is :const:`sNaN` which signals rather than remaining quiet after every +operation. This is a useful return value when an invalid result needs to +interrupt a calculation for special handling. + +The signed zeros can result from calculations that underflow. They keep the sign +that would have resulted if the calculation had been carried out to greater +precision. Since their magnitude is zero, both positive and negative zeros are +treated as equal and their sign is informational. + +In addition to the two signed zeros which are distinct yet equal, there are +various representations of zero with differing precisions yet equivalent in +value. This takes a bit of getting used to. For an eye accustomed to +normalized floating point representations, it is not immediately obvious that +the following calculation returns a value equal to zero:: + + >>> 1 / Decimal('Infinity') + Decimal("0E-1000000026") + +.. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +.. _decimal-threads: + +Working with threads +-------------------- + +The :func:`getcontext` function accesses a different :class:`Context` object for +each thread. Having separate thread contexts means that threads may make +changes (such as ``getcontext.prec=10``) without interfering with other threads. + +Likewise, the :func:`setcontext` function automatically assigns its target to +the current thread. + +If :func:`setcontext` has not been called before :func:`getcontext`, then +:func:`getcontext` will automatically create a new context for use in the +current thread. + +The new context is copied from a prototype context called *DefaultContext*. To +control the defaults so that each thread will use the same values throughout the +application, directly modify the *DefaultContext* object. This should be done +*before* any threads are started so that there won't be a race condition between +threads calling :func:`getcontext`. For example:: + + # Set applicationwide defaults for all threads about to be launched + DefaultContext.prec = 12 + DefaultContext.rounding = ROUND_DOWN + DefaultContext.traps = ExtendedContext.traps.copy() + DefaultContext.traps[InvalidOperation] = 1 + setcontext(DefaultContext) + + # Afterwards, the threads can be started + t1.start() + t2.start() + t3.start() + . . . + +.. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +.. _decimal-recipes: + +Recipes +------- + +Here are a few recipes that serve as utility functions and that demonstrate ways +to work with the :class:`Decimal` class:: + + def moneyfmt(value, places=2, curr='', sep=',', dp='.', + pos='', neg='-', trailneg=''): + """Convert Decimal to a money formatted string. + + places: required number of places after the decimal point + curr: optional currency symbol before the sign (may be blank) + sep: optional grouping separator (comma, period, space, or blank) + dp: decimal point indicator (comma or period) + only specify as blank when places is zero + pos: optional sign for positive numbers: '+', space or blank + neg: optional sign for negative numbers: '-', '(', space or blank + trailneg:optional trailing minus indicator: '-', ')', space or blank + + >>> d = Decimal('-1234567.8901') + >>> moneyfmt(d, curr='$') + '-$1,234,567.89' + >>> moneyfmt(d, places=0, sep='.', dp='', neg='', trailneg='-') + '1.234.568-' + >>> moneyfmt(d, curr='$', neg='(', trailneg=')') + '($1,234,567.89)' + >>> moneyfmt(Decimal(123456789), sep=' ') + '123 456 789.00' + >>> moneyfmt(Decimal('-0.02'), neg='<', trailneg='>') + '<.02>' + + """ + q = Decimal((0, (1,), -places)) # 2 places --> '0.01' + sign, digits, exp = value.quantize(q).as_tuple() + assert exp == -places + result = [] + digits = map(str, digits) + build, next = result.append, digits.pop + if sign: + build(trailneg) + for i in range(places): + if digits: + build(next()) + else: + build('0') + build(dp) + i = 0 + while digits: + build(next()) + i += 1 + if i == 3 and digits: + i = 0 + build(sep) + build(curr) + if sign: + build(neg) + else: + build(pos) + result.reverse() + return ''.join(result) + + def pi(): + """Compute Pi to the current precision. + + >>> print pi() + 3.141592653589793238462643383 + + """ + getcontext().prec += 2 # extra digits for intermediate steps + three = Decimal(3) # substitute "three=3.0" for regular floats + lasts, t, s, n, na, d, da = 0, three, 3, 1, 0, 0, 24 + while s != lasts: + lasts = s + n, na = n+na, na+8 + d, da = d+da, da+32 + t = (t * n) / d + s += t + getcontext().prec -= 2 + return +s # unary plus applies the new precision + + def exp(x): + """Return e raised to the power of x. Result type matches input type. + + >>> print exp(Decimal(1)) + 2.718281828459045235360287471 + >>> print exp(Decimal(2)) + 7.389056098930650227230427461 + >>> print exp(2.0) + 7.38905609893 + >>> print exp(2+0j) + (7.38905609893+0j) + + """ + getcontext().prec += 2 + i, lasts, s, fact, num = 0, 0, 1, 1, 1 + while s != lasts: + lasts = s + i += 1 + fact *= i + num *= x + s += num / fact + getcontext().prec -= 2 + return +s + + def cos(x): + """Return the cosine of x as measured in radians. + + >>> print cos(Decimal('0.5')) + 0.8775825618903727161162815826 + >>> print cos(0.5) + 0.87758256189 + >>> print cos(0.5+0j) + (0.87758256189+0j) + + """ + getcontext().prec += 2 + i, lasts, s, fact, num, sign = 0, 0, 1, 1, 1, 1 + while s != lasts: + lasts = s + i += 2 + fact *= i * (i-1) + num *= x * x + sign *= -1 + s += num / fact * sign + getcontext().prec -= 2 + return +s + + def sin(x): + """Return the sine of x as measured in radians. + + >>> print sin(Decimal('0.5')) + 0.4794255386042030002732879352 + >>> print sin(0.5) + 0.479425538604 + >>> print sin(0.5+0j) + (0.479425538604+0j) + + """ + getcontext().prec += 2 + i, lasts, s, fact, num, sign = 1, 0, x, 1, x, 1 + while s != lasts: + lasts = s + i += 2 + fact *= i * (i-1) + num *= x * x + sign *= -1 + s += num / fact * sign + getcontext().prec -= 2 + return +s + + +.. % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + + +.. _decimal-faq: + +Decimal FAQ +----------- + +Q. It is cumbersome to type ``decimal.Decimal('1234.5')``. Is there a way to +minimize typing when using the interactive interpreter? + +\A. Some users abbreviate the constructor to just a single letter:: + + >>> D = decimal.Decimal + >>> D('1.23') + D('3.45') + Decimal("4.68") + +Q. In a fixed-point application with two decimal places, some inputs have many +places and need to be rounded. Others are not supposed to have excess digits +and need to be validated. What methods should be used? + +A. The :meth:`quantize` method rounds to a fixed number of decimal places. If +the :const:`Inexact` trap is set, it is also useful for validation:: + + >>> TWOPLACES = Decimal(10) ** -2 # same as Decimal('0.01') + + >>> # Round to two places + >>> Decimal("3.214").quantize(TWOPLACES) + Decimal("3.21") + + >>> # Validate that a number does not exceed two places + >>> Decimal("3.21").quantize(TWOPLACES, context=Context(traps=[Inexact])) + Decimal("3.21") + + >>> Decimal("3.214").quantize(TWOPLACES, context=Context(traps=[Inexact])) + Traceback (most recent call last): + ... + Inexact: Changed in rounding + +Q. Once I have valid two place inputs, how do I maintain that invariant +throughout an application? + +A. Some operations like addition and subtraction automatically preserve fixed +point. Others, like multiplication and division, change the number of decimal +places and need to be followed-up with a :meth:`quantize` step. + +Q. There are many ways to express the same value. The numbers :const:`200`, +:const:`200.000`, :const:`2E2`, and :const:`.02E+4` all have the same value at +various precisions. Is there a way to transform them to a single recognizable +canonical value? + +A. The :meth:`normalize` method maps all equivalent values to a single +representative:: + + >>> values = map(Decimal, '200 200.000 2E2 .02E+4'.split()) + >>> [v.normalize() for v in values] + [Decimal("2E+2"), Decimal("2E+2"), Decimal("2E+2"), Decimal("2E+2")] + +Q. Some decimal values always print with exponential notation. Is there a way +to get a non-exponential representation? + +A. For some values, exponential notation is the only way to express the number +of significant places in the coefficient. For example, expressing +:const:`5.0E+3` as :const:`5000` keeps the value constant but cannot show the +original's two-place significance. + +Q. Is there a way to convert a regular float to a :class:`Decimal`? + +A. Yes, all binary floating point numbers can be exactly expressed as a +Decimal. An exact conversion may take more precision than intuition would +suggest, so trapping :const:`Inexact` will signal a need for more precision:: + + def floatToDecimal(f): + "Convert a floating point number to a Decimal with no loss of information" + # Transform (exactly) a float to a mantissa (0.5 <= abs(m) < 1.0) and an + # exponent. Double the mantissa until it is an integer. Use the integer + # mantissa and exponent to compute an equivalent Decimal. If this cannot + # be done exactly, then retry with more precision. + + mantissa, exponent = math.frexp(f) + while mantissa != int(mantissa): + mantissa *= 2.0 + exponent -= 1 + mantissa = int(mantissa) + + oldcontext = getcontext() + setcontext(Context(traps=[Inexact])) + try: + while True: + try: + return mantissa * Decimal(2) ** exponent + except Inexact: + getcontext().prec += 1 + finally: + setcontext(oldcontext) + +Q. Why isn't the :func:`floatToDecimal` routine included in the module? + +A. There is some question about whether it is advisable to mix binary and +decimal floating point. Also, its use requires some care to avoid the +representation issues associated with binary floating point:: + + >>> floatToDecimal(1.1) + Decimal("1.100000000000000088817841970012523233890533447265625") + +Q. Within a complex calculation, how can I make sure that I haven't gotten a +spurious result because of insufficient precision or rounding anomalies. + +A. The decimal module makes it easy to test results. A best practice is to +re-run calculations using greater precision and with various rounding modes. +Widely differing results indicate insufficient precision, rounding mode issues, +ill-conditioned inputs, or a numerically unstable algorithm. + +Q. I noticed that context precision is applied to the results of operations but +not to the inputs. Is there anything to watch out for when mixing values of +different precisions? + +A. Yes. The principle is that all values are considered to be exact and so is +the arithmetic on those values. Only the results are rounded. The advantage +for inputs is that "what you type is what you get". A disadvantage is that the +results can look odd if you forget that the inputs haven't been rounded:: + + >>> getcontext().prec = 3 + >>> Decimal('3.104') + D('2.104') + Decimal("5.21") + >>> Decimal('3.104') + D('0.000') + D('2.104') + Decimal("5.20") + +The solution is either to increase precision or to force rounding of inputs +using the unary plus operation:: + + >>> getcontext().prec = 3 + >>> +Decimal('1.23456789') # unary plus triggers rounding + Decimal("1.23") + +Alternatively, inputs can be rounded upon creation using the +:meth:`Context.create_decimal` method:: + + >>> Context(prec=5, rounding=ROUND_DOWN).create_decimal('1.2345678') + Decimal("1.2345") + diff --git a/Doc/library/development.rst b/Doc/library/development.rst new file mode 100644 index 0000000..be8c33d --- /dev/null +++ b/Doc/library/development.rst @@ -0,0 +1,22 @@ + +.. _development: + +***************** +Development Tools +***************** + +The modules described in this chapter help you write software. For example, the +:mod:`pydoc` module takes a module and generates documentation based on the +module's contents. The :mod:`doctest` and :mod:`unittest` modules contains +frameworks for writing unit tests that automatically exercise code and verify +that the expected output is produced. + +The list of modules described in this chapter is: + + +.. toctree:: + + pydoc.rst + doctest.rst + unittest.rst + test.rst diff --git a/Doc/library/difflib.rst b/Doc/library/difflib.rst new file mode 100644 index 0000000..95b83e6 --- /dev/null +++ b/Doc/library/difflib.rst @@ -0,0 +1,644 @@ + +:mod:`difflib` --- Helpers for computing deltas +=============================================== + +.. module:: difflib + :synopsis: Helpers for computing differences between objects. +.. moduleauthor:: Tim Peters +.. sectionauthor:: Tim Peters + + +.. % LaTeXification by Fred L. Drake, Jr. . + +.. versionadded:: 2.1 + + +.. class:: SequenceMatcher + + This is a flexible class for comparing pairs of sequences of any type, so long + as the sequence elements are hashable. The basic algorithm predates, and is a + little fancier than, an algorithm published in the late 1980's by Ratcliff and + Obershelp under the hyperbolic name "gestalt pattern matching." The idea is to + find the longest contiguous matching subsequence that contains no "junk" + elements (the Ratcliff and Obershelp algorithm doesn't address junk). The same + idea is then applied recursively to the pieces of the sequences to the left and + to the right of the matching subsequence. This does not yield minimal edit + sequences, but does tend to yield matches that "look right" to people. + + **Timing:** The basic Ratcliff-Obershelp algorithm is cubic time in the worst + case and quadratic time in the expected case. :class:`SequenceMatcher` is + quadratic time for the worst case and has expected-case behavior dependent in a + complicated way on how many elements the sequences have in common; best case + time is linear. + + +.. class:: Differ + + This is a class for comparing sequences of lines of text, and producing + human-readable differences or deltas. Differ uses :class:`SequenceMatcher` + both to compare sequences of lines, and to compare sequences of characters + within similar (near-matching) lines. + + Each line of a :class:`Differ` delta begins with a two-letter code: + + +----------+-------------------------------------------+ + | Code | Meaning | + +==========+===========================================+ + | ``'- '`` | line unique to sequence 1 | + +----------+-------------------------------------------+ + | ``'+ '`` | line unique to sequence 2 | + +----------+-------------------------------------------+ + | ``' '`` | line common to both sequences | + +----------+-------------------------------------------+ + | ``'? '`` | line not present in either input sequence | + +----------+-------------------------------------------+ + + Lines beginning with '``?``' attempt to guide the eye to intraline differences, + and were not present in either input sequence. These lines can be confusing if + the sequences contain tab characters. + + +.. class:: HtmlDiff + + This class can be used to create an HTML table (or a complete HTML file + containing the table) showing a side by side, line by line comparison of text + with inter-line and intra-line change highlights. The table can be generated in + either full or contextual difference mode. + + The constructor for this class is: + + + .. function:: __init__([tabsize][, wrapcolumn][, linejunk][, charjunk]) + + Initializes instance of :class:`HtmlDiff`. + + *tabsize* is an optional keyword argument to specify tab stop spacing and + defaults to ``8``. + + *wrapcolumn* is an optional keyword to specify column number where lines are + broken and wrapped, defaults to ``None`` where lines are not wrapped. + + *linejunk* and *charjunk* are optional keyword arguments passed into ``ndiff()`` + (used by :class:`HtmlDiff` to generate the side by side HTML differences). See + ``ndiff()`` documentation for argument default values and descriptions. + + The following methods are public: + + + .. function:: make_file(fromlines, tolines [, fromdesc][, todesc][, context][, numlines]) + + Compares *fromlines* and *tolines* (lists of strings) and returns a string which + is a complete HTML file containing a table showing line by line differences with + inter-line and intra-line changes highlighted. + + *fromdesc* and *todesc* are optional keyword arguments to specify from/to file + column header strings (both default to an empty string). + + *context* and *numlines* are both optional keyword arguments. Set *context* to + ``True`` when contextual differences are to be shown, else the default is + ``False`` to show the full files. *numlines* defaults to ``5``. When *context* + is ``True`` *numlines* controls the number of context lines which surround the + difference highlights. When *context* is ``False`` *numlines* controls the + number of lines which are shown before a difference highlight when using the + "next" hyperlinks (setting to zero would cause the "next" hyperlinks to place + the next difference highlight at the top of the browser without any leading + context). + + + .. function:: make_table(fromlines, tolines [, fromdesc][, todesc][, context][, numlines]) + + Compares *fromlines* and *tolines* (lists of strings) and returns a string which + is a complete HTML table showing line by line differences with inter-line and + intra-line changes highlighted. + + The arguments for this method are the same as those for the :meth:`make_file` + method. + + :file:`Tools/scripts/diff.py` is a command-line front-end to this class and + contains a good example of its use. + + .. versionadded:: 2.4 + + +.. function:: context_diff(a, b[, fromfile][, tofile][, fromfiledate][, tofiledate][, n][, lineterm]) + + Compare *a* and *b* (lists of strings); return a delta (a generator generating + the delta lines) in context diff format. + + Context diffs are a compact way of showing just the lines that have changed plus + a few lines of context. The changes are shown in a before/after style. The + number of context lines is set by *n* which defaults to three. + + By default, the diff control lines (those with ``***`` or ``---``) are created + with a trailing newline. This is helpful so that inputs created from + :func:`file.readlines` result in diffs that are suitable for use with + :func:`file.writelines` since both the inputs and outputs have trailing + newlines. + + For inputs that do not have trailing newlines, set the *lineterm* argument to + ``""`` so that the output will be uniformly newline free. + + The context diff format normally has a header for filenames and modification + times. Any or all of these may be specified using strings for *fromfile*, + *tofile*, *fromfiledate*, and *tofiledate*. The modification times are normally + expressed in the format returned by :func:`time.ctime`. If not specified, the + strings default to blanks. + + :file:`Tools/scripts/diff.py` is a command-line front-end for this function. + + .. versionadded:: 2.3 + + +.. function:: get_close_matches(word, possibilities[, n][, cutoff]) + + Return a list of the best "good enough" matches. *word* is a sequence for which + close matches are desired (typically a string), and *possibilities* is a list of + sequences against which to match *word* (typically a list of strings). + + Optional argument *n* (default ``3``) is the maximum number of close matches to + return; *n* must be greater than ``0``. + + Optional argument *cutoff* (default ``0.6``) is a float in the range [0, 1]. + Possibilities that don't score at least that similar to *word* are ignored. + + The best (no more than *n*) matches among the possibilities are returned in a + list, sorted by similarity score, most similar first. :: + + >>> get_close_matches('appel', ['ape', 'apple', 'peach', 'puppy']) + ['apple', 'ape'] + >>> import keyword + >>> get_close_matches('wheel', keyword.kwlist) + ['while'] + >>> get_close_matches('apple', keyword.kwlist) + [] + >>> get_close_matches('accept', keyword.kwlist) + ['except'] + + +.. function:: ndiff(a, b[, linejunk][, charjunk]) + + Compare *a* and *b* (lists of strings); return a :class:`Differ`\ -style delta + (a generator generating the delta lines). + + Optional keyword parameters *linejunk* and *charjunk* are for filter functions + (or ``None``): + + *linejunk*: A function that accepts a single string argument, and returns true + if the string is junk, or false if not. The default is (``None``), starting with + Python 2.3. Before then, the default was the module-level function + :func:`IS_LINE_JUNK`, which filters out lines without visible characters, except + for at most one pound character (``'#'``). As of Python 2.3, the underlying + :class:`SequenceMatcher` class does a dynamic analysis of which lines are so + frequent as to constitute noise, and this usually works better than the pre-2.3 + default. + + *charjunk*: A function that accepts a character (a string of length 1), and + returns if the character is junk, or false if not. The default is module-level + function :func:`IS_CHARACTER_JUNK`, which filters out whitespace characters (a + blank or tab; note: bad idea to include newline in this!). + + :file:`Tools/scripts/ndiff.py` is a command-line front-end to this function. :: + + >>> diff = ndiff('one\ntwo\nthree\n'.splitlines(1), + ... 'ore\ntree\nemu\n'.splitlines(1)) + >>> print ''.join(diff), + - one + ? ^ + + ore + ? ^ + - two + - three + ? - + + tree + + emu + + +.. function:: restore(sequence, which) + + Return one of the two sequences that generated a delta. + + Given a *sequence* produced by :meth:`Differ.compare` or :func:`ndiff`, extract + lines originating from file 1 or 2 (parameter *which*), stripping off line + prefixes. + + Example:: + + >>> diff = ndiff('one\ntwo\nthree\n'.splitlines(1), + ... 'ore\ntree\nemu\n'.splitlines(1)) + >>> diff = list(diff) # materialize the generated delta into a list + >>> print ''.join(restore(diff, 1)), + one + two + three + >>> print ''.join(restore(diff, 2)), + ore + tree + emu + + +.. function:: unified_diff(a, b[, fromfile][, tofile][, fromfiledate][, tofiledate][, n][, lineterm]) + + Compare *a* and *b* (lists of strings); return a delta (a generator generating + the delta lines) in unified diff format. + + Unified diffs are a compact way of showing just the lines that have changed plus + a few lines of context. The changes are shown in a inline style (instead of + separate before/after blocks). The number of context lines is set by *n* which + defaults to three. + + By default, the diff control lines (those with ``---``, ``+++``, or ``@@``) are + created with a trailing newline. This is helpful so that inputs created from + :func:`file.readlines` result in diffs that are suitable for use with + :func:`file.writelines` since both the inputs and outputs have trailing + newlines. + + For inputs that do not have trailing newlines, set the *lineterm* argument to + ``""`` so that the output will be uniformly newline free. + + The context diff format normally has a header for filenames and modification + times. Any or all of these may be specified using strings for *fromfile*, + *tofile*, *fromfiledate*, and *tofiledate*. The modification times are normally + expressed in the format returned by :func:`time.ctime`. If not specified, the + strings default to blanks. + + :file:`Tools/scripts/diff.py` is a command-line front-end for this function. + + .. versionadded:: 2.3 + + +.. function:: IS_LINE_JUNK(line) + + Return true for ignorable lines. The line *line* is ignorable if *line* is + blank or contains a single ``'#'``, otherwise it is not ignorable. Used as a + default for parameter *linejunk* in :func:`ndiff` before Python 2.3. + + +.. function:: IS_CHARACTER_JUNK(ch) + + Return true for ignorable characters. The character *ch* is ignorable if *ch* + is a space or tab, otherwise it is not ignorable. Used as a default for + parameter *charjunk* in :func:`ndiff`. + + +.. seealso:: + + `Pattern Matching: The Gestalt Approach `_ + Discussion of a similar algorithm by John W. Ratcliff and D. E. Metzener. This + was published in `Dr. Dobb's Journal `_ in July, 1988. + + +.. _sequence-matcher: + +SequenceMatcher Objects +----------------------- + +The :class:`SequenceMatcher` class has this constructor: + + +.. class:: SequenceMatcher([isjunk[, a[, b]]]) + + Optional argument *isjunk* must be ``None`` (the default) or a one-argument + function that takes a sequence element and returns true if and only if the + element is "junk" and should be ignored. Passing ``None`` for *isjunk* is + equivalent to passing ``lambda x: 0``; in other words, no elements are ignored. + For example, pass:: + + lambda x: x in " \t" + + if you're comparing lines as sequences of characters, and don't want to synch up + on blanks or hard tabs. + + The optional arguments *a* and *b* are sequences to be compared; both default to + empty strings. The elements of both sequences must be hashable. + +:class:`SequenceMatcher` objects have the following methods: + + +.. method:: SequenceMatcher.set_seqs(a, b) + + Set the two sequences to be compared. + +:class:`SequenceMatcher` computes and caches detailed information about the +second sequence, so if you want to compare one sequence against many sequences, +use :meth:`set_seq2` to set the commonly used sequence once and call +:meth:`set_seq1` repeatedly, once for each of the other sequences. + + +.. method:: SequenceMatcher.set_seq1(a) + + Set the first sequence to be compared. The second sequence to be compared is + not changed. + + +.. method:: SequenceMatcher.set_seq2(b) + + Set the second sequence to be compared. The first sequence to be compared is + not changed. + + +.. method:: SequenceMatcher.find_longest_match(alo, ahi, blo, bhi) + + Find longest matching block in ``a[alo:ahi]`` and ``b[blo:bhi]``. + + If *isjunk* was omitted or ``None``, :meth:`get_longest_match` returns ``(i, j, + k)`` such that ``a[i:i+k]`` is equal to ``b[j:j+k]``, where ``alo <= i <= i+k <= + ahi`` and ``blo <= j <= j+k <= bhi``. For all ``(i', j', k')`` meeting those + conditions, the additional conditions ``k >= k'``, ``i <= i'``, and if ``i == + i'``, ``j <= j'`` are also met. In other words, of all maximal matching blocks, + return one that starts earliest in *a*, and of all those maximal matching blocks + that start earliest in *a*, return the one that starts earliest in *b*. :: + + >>> s = SequenceMatcher(None, " abcd", "abcd abcd") + >>> s.find_longest_match(0, 5, 0, 9) + (0, 4, 5) + + If *isjunk* was provided, first the longest matching block is determined as + above, but with the additional restriction that no junk element appears in the + block. Then that block is extended as far as possible by matching (only) junk + elements on both sides. So the resulting block never matches on junk except as + identical junk happens to be adjacent to an interesting match. + + Here's the same example as before, but considering blanks to be junk. That + prevents ``' abcd'`` from matching the ``' abcd'`` at the tail end of the second + sequence directly. Instead only the ``'abcd'`` can match, and matches the + leftmost ``'abcd'`` in the second sequence:: + + >>> s = SequenceMatcher(lambda x: x==" ", " abcd", "abcd abcd") + >>> s.find_longest_match(0, 5, 0, 9) + (1, 0, 4) + + If no blocks match, this returns ``(alo, blo, 0)``. + + +.. method:: SequenceMatcher.get_matching_blocks() + + Return list of triples describing matching subsequences. Each triple is of the + form ``(i, j, n)``, and means that ``a[i:i+n] == b[j:j+n]``. The triples are + monotonically increasing in *i* and *j*. + + The last triple is a dummy, and has the value ``(len(a), len(b), 0)``. It is + the only triple with ``n == 0``. If ``(i, j, n)`` and ``(i', j', n')`` are + adjacent triples in the list, and the second is not the last triple in the list, + then ``i+n != i'`` or ``j+n != j'``; in other words, adjacent triples always + describe non-adjacent equal blocks. + + .. % Explain why a dummy is used! + + .. versionchanged:: 2.5 + The guarantee that adjacent triples always describe non-adjacent blocks was + implemented. + + :: + + >>> s = SequenceMatcher(None, "abxcd", "abcd") + >>> s.get_matching_blocks() + [(0, 0, 2), (3, 2, 2), (5, 4, 0)] + + +.. method:: SequenceMatcher.get_opcodes() + + Return list of 5-tuples describing how to turn *a* into *b*. Each tuple is of + the form ``(tag, i1, i2, j1, j2)``. The first tuple has ``i1 == j1 == 0``, and + remaining tuples have *i1* equal to the *i2* from the preceding tuple, and, + likewise, *j1* equal to the previous *j2*. + + The *tag* values are strings, with these meanings: + + +---------------+---------------------------------------------+ + | Value | Meaning | + +===============+=============================================+ + | ``'replace'`` | ``a[i1:i2]`` should be replaced by | + | | ``b[j1:j2]``. | + +---------------+---------------------------------------------+ + | ``'delete'`` | ``a[i1:i2]`` should be deleted. Note that | + | | ``j1 == j2`` in this case. | + +---------------+---------------------------------------------+ + | ``'insert'`` | ``b[j1:j2]`` should be inserted at | + | | ``a[i1:i1]``. Note that ``i1 == i2`` in | + | | this case. | + +---------------+---------------------------------------------+ + | ``'equal'`` | ``a[i1:i2] == b[j1:j2]`` (the sub-sequences | + | | are equal). | + +---------------+---------------------------------------------+ + + For example:: + + >>> a = "qabxcd" + >>> b = "abycdf" + >>> s = SequenceMatcher(None, a, b) + >>> for tag, i1, i2, j1, j2 in s.get_opcodes(): + ... print ("%7s a[%d:%d] (%s) b[%d:%d] (%s)" % + ... (tag, i1, i2, a[i1:i2], j1, j2, b[j1:j2])) + delete a[0:1] (q) b[0:0] () + equal a[1:3] (ab) b[0:2] (ab) + replace a[3:4] (x) b[2:3] (y) + equal a[4:6] (cd) b[3:5] (cd) + insert a[6:6] () b[5:6] (f) + + +.. method:: SequenceMatcher.get_grouped_opcodes([n]) + + Return a generator of groups with up to *n* lines of context. + + Starting with the groups returned by :meth:`get_opcodes`, this method splits out + smaller change clusters and eliminates intervening ranges which have no changes. + + The groups are returned in the same format as :meth:`get_opcodes`. + + .. versionadded:: 2.3 + + +.. method:: SequenceMatcher.ratio() + + Return a measure of the sequences' similarity as a float in the range [0, 1]. + + Where T is the total number of elements in both sequences, and M is the number + of matches, this is 2.0\*M / T. Note that this is ``1.0`` if the sequences are + identical, and ``0.0`` if they have nothing in common. + + This is expensive to compute if :meth:`get_matching_blocks` or + :meth:`get_opcodes` hasn't already been called, in which case you may want to + try :meth:`quick_ratio` or :meth:`real_quick_ratio` first to get an upper bound. + + +.. method:: SequenceMatcher.quick_ratio() + + Return an upper bound on :meth:`ratio` relatively quickly. + + This isn't defined beyond that it is an upper bound on :meth:`ratio`, and is + faster to compute. + + +.. method:: SequenceMatcher.real_quick_ratio() + + Return an upper bound on :meth:`ratio` very quickly. + + This isn't defined beyond that it is an upper bound on :meth:`ratio`, and is + faster to compute than either :meth:`ratio` or :meth:`quick_ratio`. + +The three methods that return the ratio of matching to total characters can give +different results due to differing levels of approximation, although +:meth:`quick_ratio` and :meth:`real_quick_ratio` are always at least as large as +:meth:`ratio`:: + + >>> s = SequenceMatcher(None, "abcd", "bcde") + >>> s.ratio() + 0.75 + >>> s.quick_ratio() + 0.75 + >>> s.real_quick_ratio() + 1.0 + + +.. _sequencematcher-examples: + +SequenceMatcher Examples +------------------------ + +This example compares two strings, considering blanks to be "junk:" :: + + >>> s = SequenceMatcher(lambda x: x == " ", + ... "private Thread currentThread;", + ... "private volatile Thread currentThread;") + +:meth:`ratio` returns a float in [0, 1], measuring the similarity of the +sequences. As a rule of thumb, a :meth:`ratio` value over 0.6 means the +sequences are close matches:: + + >>> print round(s.ratio(), 3) + 0.866 + +If you're only interested in where the sequences match, +:meth:`get_matching_blocks` is handy:: + + >>> for block in s.get_matching_blocks(): + ... print "a[%d] and b[%d] match for %d elements" % block + a[0] and b[0] match for 8 elements + a[8] and b[17] match for 6 elements + a[14] and b[23] match for 15 elements + a[29] and b[38] match for 0 elements + +Note that the last tuple returned by :meth:`get_matching_blocks` is always a +dummy, ``(len(a), len(b), 0)``, and this is the only case in which the last +tuple element (number of elements matched) is ``0``. + +If you want to know how to change the first sequence into the second, use +:meth:`get_opcodes`:: + + >>> for opcode in s.get_opcodes(): + ... print "%6s a[%d:%d] b[%d:%d]" % opcode + equal a[0:8] b[0:8] + insert a[8:8] b[8:17] + equal a[8:14] b[17:23] + equal a[14:29] b[23:38] + +See also the function :func:`get_close_matches` in this module, which shows how +simple code building on :class:`SequenceMatcher` can be used to do useful work. + + +.. _differ-objects: + +Differ Objects +-------------- + +Note that :class:`Differ`\ -generated deltas make no claim to be **minimal** +diffs. To the contrary, minimal diffs are often counter-intuitive, because they +synch up anywhere possible, sometimes accidental matches 100 pages apart. +Restricting synch points to contiguous matches preserves some notion of +locality, at the occasional cost of producing a longer diff. + +The :class:`Differ` class has this constructor: + + +.. class:: Differ([linejunk[, charjunk]]) + + Optional keyword parameters *linejunk* and *charjunk* are for filter functions + (or ``None``): + + *linejunk*: A function that accepts a single string argument, and returns true + if the string is junk. The default is ``None``, meaning that no line is + considered junk. + + *charjunk*: A function that accepts a single character argument (a string of + length 1), and returns true if the character is junk. The default is ``None``, + meaning that no character is considered junk. + +:class:`Differ` objects are used (deltas generated) via a single method: + + +.. method:: Differ.compare(a, b) + + Compare two sequences of lines, and generate the delta (a sequence of lines). + + Each sequence must contain individual single-line strings ending with newlines. + Such sequences can be obtained from the :meth:`readlines` method of file-like + objects. The delta generated also consists of newline-terminated strings, ready + to be printed as-is via the :meth:`writelines` method of a file-like object. + + +.. _differ-examples: + +Differ Example +-------------- + +This example compares two texts. First we set up the texts, sequences of +individual single-line strings ending with newlines (such sequences can also be +obtained from the :meth:`readlines` method of file-like objects):: + + >>> text1 = ''' 1. Beautiful is better than ugly. + ... 2. Explicit is better than implicit. + ... 3. Simple is better than complex. + ... 4. Complex is better than complicated. + ... '''.splitlines(1) + >>> len(text1) + 4 + >>> text1[0][-1] + '\n' + >>> text2 = ''' 1. Beautiful is better than ugly. + ... 3. Simple is better than complex. + ... 4. Complicated is better than complex. + ... 5. Flat is better than nested. + ... '''.splitlines(1) + +Next we instantiate a Differ object:: + + >>> d = Differ() + +Note that when instantiating a :class:`Differ` object we may pass functions to +filter out line and character "junk." See the :meth:`Differ` constructor for +details. + +Finally, we compare the two:: + + >>> result = list(d.compare(text1, text2)) + +``result`` is a list of strings, so let's pretty-print it:: + + >>> from pprint import pprint + >>> pprint(result) + [' 1. Beautiful is better than ugly.\n', + '- 2. Explicit is better than implicit.\n', + '- 3. Simple is better than complex.\n', + '+ 3. Simple is better than complex.\n', + '? ++ \n', + '- 4. Complex is better than complicated.\n', + '? ^ ---- ^ \n', + '+ 4. Complicated is better than complex.\n', + '? ++++ ^ ^ \n', + '+ 5. Flat is better than nested.\n'] + +As a single multi-line string it looks like this:: + + >>> import sys + >>> sys.stdout.writelines(result) + 1. Beautiful is better than ugly. + - 2. Explicit is better than implicit. + - 3. Simple is better than complex. + + 3. Simple is better than complex. + ? ++ + - 4. Complex is better than complicated. + ? ^ ---- ^ + + 4. Complicated is better than complex. + ? ++++ ^ ^ + + 5. Flat is better than nested. + diff --git a/Doc/library/dircache.rst b/Doc/library/dircache.rst new file mode 100644 index 0000000..28aa667 --- /dev/null +++ b/Doc/library/dircache.rst @@ -0,0 +1,56 @@ + +:mod:`dircache` --- Cached directory listings +============================================= + +.. module:: dircache + :synopsis: Return directory listing, with cache mechanism. +.. sectionauthor:: Moshe Zadka + + +The :mod:`dircache` module defines a function for reading directory listing +using a cache, and cache invalidation using the *mtime* of the directory. +Additionally, it defines a function to annotate directories by appending a +slash. + +The :mod:`dircache` module defines the following functions: + + +.. function:: reset() + + Resets the directory cache. + + +.. function:: listdir(path) + + Return a directory listing of *path*, as gotten from :func:`os.listdir`. Note + that unless *path* changes, further call to :func:`listdir` will not re-read the + directory structure. + + Note that the list returned should be regarded as read-only. (Perhaps a future + version should change it to return a tuple?) + + +.. function:: opendir(path) + + Same as :func:`listdir`. Defined for backwards compatibility. + + +.. function:: annotate(head, list) + + Assume *list* is a list of paths relative to *head*, and append, in place, a + ``'/'`` to each path which points to a directory. + +:: + + >>> import dircache + >>> a = dircache.listdir('/') + >>> a = a[:] # Copy the return value so we can change 'a' + >>> a + ['bin', 'boot', 'cdrom', 'dev', 'etc', 'floppy', 'home', 'initrd', 'lib', 'lost+ + found', 'mnt', 'proc', 'root', 'sbin', 'tmp', 'usr', 'var', 'vmlinuz'] + >>> dircache.annotate('/', a) + >>> a + ['bin/', 'boot/', 'cdrom/', 'dev/', 'etc/', 'floppy/', 'home/', 'initrd/', 'lib/ + ', 'lost+found/', 'mnt/', 'proc/', 'root/', 'sbin/', 'tmp/', 'usr/', 'var/', 'vm + linuz'] + diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst new file mode 100644 index 0000000..5f28473 --- /dev/null +++ b/Doc/library/dis.rst @@ -0,0 +1,775 @@ + +:mod:`dis` --- Disassembler for Python byte code +================================================ + +.. module:: dis + :synopsis: Disassembler for Python byte code. + + +The :mod:`dis` module supports the analysis of Python byte code by disassembling +it. Since there is no Python assembler, this module defines the Python assembly +language. The Python byte code which this module takes as an input is defined +in the file :file:`Include/opcode.h` and used by the compiler and the +interpreter. + +Example: Given the function :func:`myfunc`:: + + def myfunc(alist): + return len(alist) + +the following command can be used to get the disassembly of :func:`myfunc`:: + + >>> dis.dis(myfunc) + 2 0 LOAD_GLOBAL 0 (len) + 3 LOAD_FAST 0 (alist) + 6 CALL_FUNCTION 1 + 9 RETURN_VALUE + +(The "2" is a line number). + +The :mod:`dis` module defines the following functions and constants: + + +.. function:: dis([bytesource]) + + Disassemble the *bytesource* object. *bytesource* can denote either a module, a + class, a method, a function, or a code object. For a module, it disassembles + all functions. For a class, it disassembles all methods. For a single code + sequence, it prints one line per byte code instruction. If no object is + provided, it disassembles the last traceback. + + +.. function:: distb([tb]) + + Disassembles the top-of-stack function of a traceback, using the last traceback + if none was passed. The instruction causing the exception is indicated. + + +.. function:: disassemble(code[, lasti]) + + Disassembles a code object, indicating the last instruction if *lasti* was + provided. The output is divided in the following columns: + + #. the line number, for the first instruction of each line + #. the current instruction, indicated as ``-->``, + #. a labelled instruction, indicated with ``>>``, + #. the address of the instruction, + #. the operation code name, + #. operation parameters, and + #. interpretation of the parameters in parentheses. + + The parameter interpretation recognizes local and global variable names, + constant values, branch targets, and compare operators. + + +.. function:: disco(code[, lasti]) + + A synonym for disassemble. It is more convenient to type, and kept for + compatibility with earlier Python releases. + + +.. data:: opname + + Sequence of operation names, indexable using the byte code. + + +.. data:: opmap + + Dictionary mapping byte codes to operation names. + + +.. data:: cmp_op + + Sequence of all compare operation names. + + +.. data:: hasconst + + Sequence of byte codes that have a constant parameter. + + +.. data:: hasfree + + Sequence of byte codes that access a free variable. + + +.. data:: hasname + + Sequence of byte codes that access an attribute by name. + + +.. data:: hasjrel + + Sequence of byte codes that have a relative jump target. + + +.. data:: hasjabs + + Sequence of byte codes that have an absolute jump target. + + +.. data:: haslocal + + Sequence of byte codes that access a local variable. + + +.. data:: hascompare + + Sequence of byte codes of Boolean operations. + + +.. _bytecodes: + +Python Byte Code Instructions +----------------------------- + +The Python compiler currently generates the following byte code instructions. + + +.. opcode:: STOP_CODE () + + Indicates end-of-code to the compiler, not used by the interpreter. + + +.. opcode:: NOP () + + Do nothing code. Used as a placeholder by the bytecode optimizer. + + +.. opcode:: POP_TOP () + + Removes the top-of-stack (TOS) item. + + +.. opcode:: ROT_TWO () + + Swaps the two top-most stack items. + + +.. opcode:: ROT_THREE () + + Lifts second and third stack item one position up, moves top down to position + three. + + +.. opcode:: ROT_FOUR () + + Lifts second, third and forth stack item one position up, moves top down to + position four. + + +.. opcode:: DUP_TOP () + + Duplicates the reference on top of the stack. + +Unary Operations take the top of the stack, apply the operation, and push the +result back on the stack. + + +.. opcode:: UNARY_POSITIVE () + + Implements ``TOS = +TOS``. + + +.. opcode:: UNARY_NEGATIVE () + + Implements ``TOS = -TOS``. + + +.. opcode:: UNARY_NOT () + + Implements ``TOS = not TOS``. + + +.. opcode:: UNARY_INVERT () + + Implements ``TOS = ~TOS``. + + +.. opcode:: GET_ITER () + + Implements ``TOS = iter(TOS)``. + +Binary operations remove the top of the stack (TOS) and the second top-most +stack item (TOS1) from the stack. They perform the operation, and put the +result back on the stack. + + +.. opcode:: BINARY_POWER () + + Implements ``TOS = TOS1 ** TOS``. + + +.. opcode:: BINARY_MULTIPLY () + + Implements ``TOS = TOS1 * TOS``. + + +.. opcode:: BINARY_FLOOR_DIVIDE () + + Implements ``TOS = TOS1 // TOS``. + + +.. opcode:: BINARY_TRUE_DIVIDE () + + Implements ``TOS = TOS1 / TOS`` when ``from __future__ import division`` is in + effect. + + +.. opcode:: BINARY_MODULO () + + Implements ``TOS = TOS1 % TOS``. + + +.. opcode:: BINARY_ADD () + + Implements ``TOS = TOS1 + TOS``. + + +.. opcode:: BINARY_SUBTRACT () + + Implements ``TOS = TOS1 - TOS``. + + +.. opcode:: BINARY_SUBSCR () + + Implements ``TOS = TOS1[TOS]``. + + +.. opcode:: BINARY_LSHIFT () + + Implements ``TOS = TOS1 << TOS``. + + +.. opcode:: BINARY_RSHIFT () + + Implements ``TOS = TOS1 >> TOS``. + + +.. opcode:: BINARY_AND () + + Implements ``TOS = TOS1 & TOS``. + + +.. opcode:: BINARY_XOR () + + Implements ``TOS = TOS1 ^ TOS``. + + +.. opcode:: BINARY_OR () + + Implements ``TOS = TOS1 | TOS``. + +In-place operations are like binary operations, in that they remove TOS and +TOS1, and push the result back on the stack, but the operation is done in-place +when TOS1 supports it, and the resulting TOS may be (but does not have to be) +the original TOS1. + + +.. opcode:: INPLACE_POWER () + + Implements in-place ``TOS = TOS1 ** TOS``. + + +.. opcode:: INPLACE_MULTIPLY () + + Implements in-place ``TOS = TOS1 * TOS``. + + +.. opcode:: INPLACE_FLOOR_DIVIDE () + + Implements in-place ``TOS = TOS1 // TOS``. + + +.. opcode:: INPLACE_TRUE_DIVIDE () + + Implements in-place ``TOS = TOS1 / TOS`` when ``from __future__ import + division`` is in effect. + + +.. opcode:: INPLACE_MODULO () + + Implements in-place ``TOS = TOS1 % TOS``. + + +.. opcode:: INPLACE_ADD () + + Implements in-place ``TOS = TOS1 + TOS``. + + +.. opcode:: INPLACE_SUBTRACT () + + Implements in-place ``TOS = TOS1 - TOS``. + + +.. opcode:: INPLACE_LSHIFT () + + Implements in-place ``TOS = TOS1 << TOS``. + + +.. opcode:: INPLACE_RSHIFT () + + Implements in-place ``TOS = TOS1 >> TOS``. + + +.. opcode:: INPLACE_AND () + + Implements in-place ``TOS = TOS1 & TOS``. + + +.. opcode:: INPLACE_XOR () + + Implements in-place ``TOS = TOS1 ^ TOS``. + + +.. opcode:: INPLACE_OR () + + Implements in-place ``TOS = TOS1 | TOS``. + +The slice opcodes take up to three parameters. + + +.. opcode:: SLICE+0 () + + Implements ``TOS = TOS[:]``. + + +.. opcode:: SLICE+1 () + + Implements ``TOS = TOS1[TOS:]``. + + +.. opcode:: SLICE+2 () + + Implements ``TOS = TOS1[:TOS]``. + + +.. opcode:: SLICE+3 () + + Implements ``TOS = TOS2[TOS1:TOS]``. + +Slice assignment needs even an additional parameter. As any statement, they put +nothing on the stack. + + +.. opcode:: STORE_SLICE+0 () + + Implements ``TOS[:] = TOS1``. + + +.. opcode:: STORE_SLICE+1 () + + Implements ``TOS1[TOS:] = TOS2``. + + +.. opcode:: STORE_SLICE+2 () + + Implements ``TOS1[:TOS] = TOS2``. + + +.. opcode:: STORE_SLICE+3 () + + Implements ``TOS2[TOS1:TOS] = TOS3``. + + +.. opcode:: DELETE_SLICE+0 () + + Implements ``del TOS[:]``. + + +.. opcode:: DELETE_SLICE+1 () + + Implements ``del TOS1[TOS:]``. + + +.. opcode:: DELETE_SLICE+2 () + + Implements ``del TOS1[:TOS]``. + + +.. opcode:: DELETE_SLICE+3 () + + Implements ``del TOS2[TOS1:TOS]``. + + +.. opcode:: STORE_SUBSCR () + + Implements ``TOS1[TOS] = TOS2``. + + +.. opcode:: DELETE_SUBSCR () + + Implements ``del TOS1[TOS]``. + +Miscellaneous opcodes. + + +.. opcode:: PRINT_EXPR () + + Implements the expression statement for the interactive mode. TOS is removed + from the stack and printed. In non-interactive mode, an expression statement is + terminated with ``POP_STACK``. + + +.. opcode:: BREAK_LOOP () + + Terminates a loop due to a :keyword:`break` statement. + + +.. opcode:: CONTINUE_LOOP (target) + + Continues a loop due to a :keyword:`continue` statement. *target* is the + address to jump to (which should be a ``FOR_ITER`` instruction). + + +.. opcode:: SET_ADD () + + Calls ``set.add(TOS1, TOS)``. Used to implement set comprehensions. + + +.. opcode:: LIST_APPEND () + + Calls ``list.append(TOS1, TOS)``. Used to implement list comprehensions. + + +.. opcode:: LOAD_LOCALS () + + Pushes a reference to the locals of the current scope on the stack. This is used + in the code for a class definition: After the class body is evaluated, the + locals are passed to the class definition. + + +.. opcode:: RETURN_VALUE () + + Returns with TOS to the caller of the function. + + +.. opcode:: YIELD_VALUE () + + Pops ``TOS`` and yields it from a generator. + + +.. opcode:: IMPORT_STAR () + + Loads all symbols not starting with ``'_'`` directly from the module TOS to the + local namespace. The module is popped after loading all names. This opcode + implements ``from module import *``. + + +.. opcode:: POP_BLOCK () + + Removes one block from the block stack. Per frame, there is a stack of blocks, + denoting nested loops, try statements, and such. + + +.. opcode:: END_FINALLY () + + Terminates a :keyword:`finally` clause. The interpreter recalls whether the + exception has to be re-raised, or whether the function returns, and continues + with the outer-next block. + + +.. opcode:: BUILD_CLASS () + + Creates a new class object. TOS is the methods dictionary, TOS1 the tuple of + the names of the base classes, and TOS2 the class name. + +All of the following opcodes expect arguments. An argument is two bytes, with +the more significant byte last. + + +.. opcode:: STORE_NAME (namei) + + Implements ``name = TOS``. *namei* is the index of *name* in the attribute + :attr:`co_names` of the code object. The compiler tries to use ``STORE_LOCAL`` + or ``STORE_GLOBAL`` if possible. + + +.. opcode:: DELETE_NAME (namei) + + Implements ``del name``, where *namei* is the index into :attr:`co_names` + attribute of the code object. + + +.. opcode:: UNPACK_SEQUENCE (count) + + Unpacks TOS into *count* individual values, which are put onto the stack + right-to-left. + +.. % \begin{opcodedesc}{UNPACK_LIST}{count} +.. % This opcode is obsolete. +.. % \end{opcodedesc} +.. % \begin{opcodedesc}{UNPACK_ARG}{count} +.. % This opcode is obsolete. +.. % \end{opcodedesc} + + +.. opcode:: DUP_TOPX (count) + + Duplicate *count* items, keeping them in the same order. Due to implementation + limits, *count* should be between 1 and 5 inclusive. + + +.. opcode:: STORE_ATTR (namei) + + Implements ``TOS.name = TOS1``, where *namei* is the index of name in + :attr:`co_names`. + + +.. opcode:: DELETE_ATTR (namei) + + Implements ``del TOS.name``, using *namei* as index into :attr:`co_names`. + + +.. opcode:: STORE_GLOBAL (namei) + + Works as ``STORE_NAME``, but stores the name as a global. + + +.. opcode:: DELETE_GLOBAL (namei) + + Works as ``DELETE_NAME``, but deletes a global name. + +.. % \begin{opcodedesc}{UNPACK_VARARG}{argc} +.. % This opcode is obsolete. +.. % \end{opcodedesc} + + +.. opcode:: LOAD_CONST (consti) + + Pushes ``co_consts[consti]`` onto the stack. + + +.. opcode:: LOAD_NAME (namei) + + Pushes the value associated with ``co_names[namei]`` onto the stack. + + +.. opcode:: BUILD_TUPLE (count) + + Creates a tuple consuming *count* items from the stack, and pushes the resulting + tuple onto the stack. + + +.. opcode:: BUILD_LIST (count) + + Works as ``BUILD_TUPLE``, but creates a list. + + +.. opcode:: BUILD_SET (count) + + Works as ``BUILD_TUPLE``, but creates a set. + + +.. opcode:: BUILD_MAP (zero) + + Pushes a new empty dictionary object onto the stack. The argument is ignored + and set to zero by the compiler. + + +.. opcode:: LOAD_ATTR (namei) + + Replaces TOS with ``getattr(TOS, co_names[namei])``. + + +.. opcode:: COMPARE_OP (opname) + + Performs a Boolean operation. The operation name can be found in + ``cmp_op[opname]``. + + +.. opcode:: IMPORT_NAME (namei) + + Imports the module ``co_names[namei]``. The module object is pushed onto the + stack. The current namespace is not affected: for a proper import statement, a + subsequent ``STORE_FAST`` instruction modifies the namespace. + + +.. opcode:: IMPORT_FROM (namei) + + Loads the attribute ``co_names[namei]`` from the module found in TOS. The + resulting object is pushed onto the stack, to be subsequently stored by a + ``STORE_FAST`` instruction. + + +.. opcode:: JUMP_FORWARD (delta) + + Increments byte code counter by *delta*. + + +.. opcode:: JUMP_IF_TRUE (delta) + + If TOS is true, increment the byte code counter by *delta*. TOS is left on the + stack. + + +.. opcode:: JUMP_IF_FALSE (delta) + + If TOS is false, increment the byte code counter by *delta*. TOS is not + changed. + + +.. opcode:: JUMP_ABSOLUTE (target) + + Set byte code counter to *target*. + + +.. opcode:: FOR_ITER (delta) + + ``TOS`` is an iterator. Call its :meth:`__next__` method. If this yields a new + value, push it on the stack (leaving the iterator below it). If the iterator + indicates it is exhausted ``TOS`` is popped, and the byte code counter is + incremented by *delta*. + +.. % \begin{opcodedesc}{FOR_LOOP}{delta} +.. % This opcode is obsolete. +.. % \end{opcodedesc} +.. % \begin{opcodedesc}{LOAD_LOCAL}{namei} +.. % This opcode is obsolete. +.. % \end{opcodedesc} + + +.. opcode:: LOAD_GLOBAL (namei) + + Loads the global named ``co_names[namei]`` onto the stack. + +.. % \begin{opcodedesc}{SET_FUNC_ARGS}{argc} +.. % This opcode is obsolete. +.. % \end{opcodedesc} + + +.. opcode:: SETUP_LOOP (delta) + + Pushes a block for a loop onto the block stack. The block spans from the + current instruction with a size of *delta* bytes. + + +.. opcode:: SETUP_EXCEPT (delta) + + Pushes a try block from a try-except clause onto the block stack. *delta* points + to the first except block. + + +.. opcode:: SETUP_FINALLY (delta) + + Pushes a try block from a try-except clause onto the block stack. *delta* points + to the finally block. + + +.. opcode:: LOAD_FAST (var_num) + + Pushes a reference to the local ``co_varnames[var_num]`` onto the stack. + + +.. opcode:: STORE_FAST (var_num) + + Stores TOS into the local ``co_varnames[var_num]``. + + +.. opcode:: DELETE_FAST (var_num) + + Deletes local ``co_varnames[var_num]``. + + +.. opcode:: LOAD_CLOSURE (i) + + Pushes a reference to the cell contained in slot *i* of the cell and free + variable storage. The name of the variable is ``co_cellvars[i]`` if *i* is + less than the length of *co_cellvars*. Otherwise it is ``co_freevars[i - + len(co_cellvars)]``. + + +.. opcode:: LOAD_DEREF (i) + + Loads the cell contained in slot *i* of the cell and free variable storage. + Pushes a reference to the object the cell contains on the stack. + + +.. opcode:: STORE_DEREF (i) + + Stores TOS into the cell contained in slot *i* of the cell and free variable + storage. + + +.. opcode:: SET_LINENO (lineno) + + This opcode is obsolete. + + +.. opcode:: RAISE_VARARGS (argc) + + Raises an exception. *argc* indicates the number of parameters to the raise + statement, ranging from 0 to 3. The handler will find the traceback as TOS2, + the parameter as TOS1, and the exception as TOS. + + +.. opcode:: CALL_FUNCTION (argc) + + Calls a function. The low byte of *argc* indicates the number of positional + parameters, the high byte the number of keyword parameters. On the stack, the + opcode finds the keyword parameters first. For each keyword argument, the value + is on top of the key. Below the keyword parameters, the positional parameters + are on the stack, with the right-most parameter on top. Below the parameters, + the function object to call is on the stack. + + +.. opcode:: MAKE_FUNCTION (argc) + + Pushes a new function object on the stack. TOS is the code associated with the + function. The function object is defined to have *argc* default parameters, + which are found below TOS. + + +.. opcode:: MAKE_CLOSURE (argc) + + Creates a new function object, sets its *__closure__* slot, and pushes it on the + stack. TOS is the code associated with the function. If the code object has N + free variables, the next N items on the stack are the cells for these variables. + The function also has *argc* default parameters, where are found before the + cells. + + +.. opcode:: BUILD_SLICE (argc) + + .. index:: builtin: slice + + Pushes a slice object on the stack. *argc* must be 2 or 3. If it is 2, + ``slice(TOS1, TOS)`` is pushed; if it is 3, ``slice(TOS2, TOS1, TOS)`` is + pushed. See the ``slice()`` built-in function for more information. + + +.. opcode:: EXTENDED_ARG (ext) + + Prefixes any opcode which has an argument too big to fit into the default two + bytes. *ext* holds two additional bytes which, taken together with the + subsequent opcode's argument, comprise a four-byte argument, *ext* being the two + most-significant bytes. + + +.. opcode:: CALL_FUNCTION_VAR (argc) + + Calls a function. *argc* is interpreted as in ``CALL_FUNCTION``. The top element + on the stack contains the variable argument list, followed by keyword and + positional arguments. + + +.. opcode:: CALL_FUNCTION_KW (argc) + + Calls a function. *argc* is interpreted as in ``CALL_FUNCTION``. The top element + on the stack contains the keyword arguments dictionary, followed by explicit + keyword and positional arguments. + + +.. opcode:: CALL_FUNCTION_VAR_KW (argc) + + Calls a function. *argc* is interpreted as in ``CALL_FUNCTION``. The top + element on the stack contains the keyword arguments dictionary, followed by the + variable-arguments tuple, followed by explicit keyword and positional arguments. + + +.. opcode:: HAVE_ARGUMENT () + + This is not really an opcode. It identifies the dividing line between opcodes + which don't take arguments ``< HAVE_ARGUMENT`` and those which do ``>= + HAVE_ARGUMENT``. + diff --git a/Doc/library/distutils.rst b/Doc/library/distutils.rst new file mode 100644 index 0000000..534faab --- /dev/null +++ b/Doc/library/distutils.rst @@ -0,0 +1,30 @@ + +:mod:`distutils` --- Building and installing Python modules +=========================================================== + +.. module:: distutils + :synopsis: Support for building and installing Python modules into an existing Python + installation. +.. sectionauthor:: Fred L. Drake, Jr. + + +The :mod:`distutils` package provides support for building and installing +additional modules into a Python installation. The new modules may be either +100%-pure Python, or may be extension modules written in C, or may be +collections of Python packages which include modules coded in both Python and C. + +This package is discussed in two separate chapters: + + +.. seealso:: + + :ref:`distutils-index` + The manual for developers and packagers of Python modules. This describes how + to prepare :mod:`distutils`\ -based packages so that they may be easily + installed into an existing Python installation. + + :ref:`install-index` + An "administrators" manual which includes information on installing modules into + an existing Python installation. You do not need to be a Python programmer to + read this manual. + diff --git a/Doc/library/dl.rst b/Doc/library/dl.rst new file mode 100644 index 0000000..ff42619 --- /dev/null +++ b/Doc/library/dl.rst @@ -0,0 +1,111 @@ + +:mod:`dl` --- Call C functions in shared objects +================================================ + +.. module:: dl + :platform: Unix + :synopsis: Call C functions in shared objects. +.. sectionauthor:: Moshe Zadka + + +.. % ?????????? Anyone???????????? + +The :mod:`dl` module defines an interface to the :cfunc:`dlopen` function, which +is the most common interface on Unix platforms for handling dynamically linked +libraries. It allows the program to call arbitrary functions in such a library. + +.. warning:: + + The :mod:`dl` module bypasses the Python type system and error handling. If + used incorrectly it may cause segmentation faults, crashes or other incorrect + behaviour. + +.. note:: + + This module will not work unless ``sizeof(int) == sizeof(long) == sizeof(char + *)`` If this is not the case, :exc:`SystemError` will be raised on import. + +The :mod:`dl` module defines the following function: + + +.. function:: open(name[, mode=RTLD_LAZY]) + + Open a shared object file, and return a handle. Mode signifies late binding + (:const:`RTLD_LAZY`) or immediate binding (:const:`RTLD_NOW`). Default is + :const:`RTLD_LAZY`. Note that some systems do not support :const:`RTLD_NOW`. + + Return value is a :class:`dlobject`. + +The :mod:`dl` module defines the following constants: + + +.. data:: RTLD_LAZY + + Useful as an argument to :func:`open`. + + +.. data:: RTLD_NOW + + Useful as an argument to :func:`open`. Note that on systems which do not + support immediate binding, this constant will not appear in the module. For + maximum portability, use :func:`hasattr` to determine if the system supports + immediate binding. + +The :mod:`dl` module defines the following exception: + + +.. exception:: error + + Exception raised when an error has occurred inside the dynamic loading and + linking routines. + +Example:: + + >>> import dl, time + >>> a=dl.open('/lib/libc.so.6') + >>> a.call('time'), time.time() + (929723914, 929723914.498) + +This example was tried on a Debian GNU/Linux system, and is a good example of +the fact that using this module is usually a bad alternative. + + +.. _dl-objects: + +Dl Objects +---------- + +Dl objects, as returned by :func:`open` above, have the following methods: + + +.. method:: dl.close() + + Free all resources, except the memory. + + +.. method:: dl.sym(name) + + Return the pointer for the function named *name*, as a number, if it exists in + the referenced shared object, otherwise ``None``. This is useful in code like:: + + >>> if a.sym('time'): + ... a.call('time') + ... else: + ... time.time() + + (Note that this function will return a non-zero number, as zero is the *NULL* + pointer) + + +.. method:: dl.call(name[, arg1[, arg2...]]) + + Call the function named *name* in the referenced shared object. The arguments + must be either Python integers, which will be passed as is, Python strings, to + which a pointer will be passed, or ``None``, which will be passed as *NULL*. + Note that strings should only be passed to functions as :ctype:`const char\*`, + as Python will not like its string mutated. + + There must be at most 10 arguments, and arguments not given will be treated as + ``None``. The function's return value must be a C :ctype:`long`, which is a + Python integer. + diff --git a/Doc/library/doctest.rst b/Doc/library/doctest.rst new file mode 100644 index 0000000..23f96e4 --- /dev/null +++ b/Doc/library/doctest.rst @@ -0,0 +1,1869 @@ +:mod:`doctest` --- Test interactive Python examples +=================================================== + +.. module:: doctest + :synopsis: Test pieces of code within docstrings. +.. moduleauthor:: Tim Peters +.. sectionauthor:: Tim Peters +.. sectionauthor:: Moshe Zadka +.. sectionauthor:: Edward Loper + + +The :mod:`doctest` module searches for pieces of text that look like interactive +Python sessions, and then executes those sessions to verify that they work +exactly as shown. There are several common ways to use doctest: + +* To check that a module's docstrings are up-to-date by verifying that all + interactive examples still work as documented. + +* To perform regression testing by verifying that interactive examples from a + test file or a test object work as expected. + +* To write tutorial documentation for a package, liberally illustrated with + input-output examples. Depending on whether the examples or the expository text + are emphasized, this has the flavor of "literate testing" or "executable + documentation". + +Here's a complete but small example module:: + + """ + This is the "example" module. + + The example module supplies one function, factorial(). For example, + + >>> factorial(5) + 120 + """ + + def factorial(n): + """Return the factorial of n, an exact integer >= 0. + + If the result is small enough to fit in an int, return an int. + Else return a long. + + >>> [factorial(n) for n in range(6)] + [1, 1, 2, 6, 24, 120] + >>> [factorial(long(n)) for n in range(6)] + [1, 1, 2, 6, 24, 120] + >>> factorial(30) + 265252859812191058636308480000000L + >>> factorial(30L) + 265252859812191058636308480000000L + >>> factorial(-1) + Traceback (most recent call last): + ... + ValueError: n must be >= 0 + + Factorials of floats are OK, but the float must be an exact integer: + >>> factorial(30.1) + Traceback (most recent call last): + ... + ValueError: n must be exact integer + >>> factorial(30.0) + 265252859812191058636308480000000L + + It must also not be ridiculously large: + >>> factorial(1e100) + Traceback (most recent call last): + ... + OverflowError: n too large + """ + + +.. % allow LaTeX to break here. + +:: + + import math + if not n >= 0: + raise ValueError("n must be >= 0") + if math.floor(n) != n: + raise ValueError("n must be exact integer") + if n+1 == n: # catch a value like 1e300 + raise OverflowError("n too large") + result = 1 + factor = 2 + while factor <= n: + result *= factor + factor += 1 + return result + + def _test(): + import doctest + doctest.testmod() + + if __name__ == "__main__": + _test() + +If you run :file:`example.py` directly from the command line, :mod:`doctest` +works its magic:: + + $ python example.py + $ + +There's no output! That's normal, and it means all the examples worked. Pass +:option:`-v` to the script, and :mod:`doctest` prints a detailed log of what +it's trying, and prints a summary at the end:: + + $ python example.py -v + Trying: + factorial(5) + Expecting: + 120 + ok + Trying: + [factorial(n) for n in range(6)] + Expecting: + [1, 1, 2, 6, 24, 120] + ok + Trying: + [factorial(long(n)) for n in range(6)] + Expecting: + [1, 1, 2, 6, 24, 120] + ok + +And so on, eventually ending with:: + + Trying: + factorial(1e100) + Expecting: + Traceback (most recent call last): + ... + OverflowError: n too large + ok + 1 items had no tests: + __main__._test + 2 items passed all tests: + 1 tests in __main__ + 8 tests in __main__.factorial + 9 tests in 3 items. + 9 passed and 0 failed. + Test passed. + $ + +That's all you need to know to start making productive use of :mod:`doctest`! +Jump in. The following sections provide full details. Note that there are many +examples of doctests in the standard Python test suite and libraries. +Especially useful examples can be found in the standard test file +:file:`Lib/test/test_doctest.py`. + + +.. _doctest-simple-testmod: + +Simple Usage: Checking Examples in Docstrings +--------------------------------------------- + +The simplest way to start using doctest (but not necessarily the way you'll +continue to do it) is to end each module :mod:`M` with:: + + def _test(): + import doctest + doctest.testmod() + + if __name__ == "__main__": + _test() + +:mod:`doctest` then examines docstrings in module :mod:`M`. + +Running the module as a script causes the examples in the docstrings to get +executed and verified:: + + python M.py + +This won't display anything unless an example fails, in which case the failing +example(s) and the cause(s) of the failure(s) are printed to stdout, and the +final line of output is ``***Test Failed*** N failures.``, where *N* is the +number of examples that failed. + +Run it with the :option:`-v` switch instead:: + + python M.py -v + +and a detailed report of all examples tried is printed to standard output, along +with assorted summaries at the end. + +You can force verbose mode by passing ``verbose=True`` to :func:`testmod`, or +prohibit it by passing ``verbose=False``. In either of those cases, +``sys.argv`` is not examined by :func:`testmod` (so passing :option:`-v` or not +has no effect). + +Since Python 2.6, there is also a command line shortcut for running +:func:`testmod`. You can instruct the Python interpreter to run the doctest +module directly from the standard library and pass the module name(s) on the +command line:: + + python -m doctest -v example.py + +This will import :file:`example.py` as a standalone module and run +:func:`testmod` on it. Note that this may not work correctly if the file is +part of a package and imports other submodules from that package. + +For more information on :func:`testmod`, see section :ref:`doctest-basic-api`. + + +.. _doctest-simple-testfile: + +Simple Usage: Checking Examples in a Text File +---------------------------------------------- + +Another simple application of doctest is testing interactive examples in a text +file. This can be done with the :func:`testfile` function:: + + import doctest + doctest.testfile("example.txt") + +That short script executes and verifies any interactive Python examples +contained in the file :file:`example.txt`. The file content is treated as if it +were a single giant docstring; the file doesn't need to contain a Python +program! For example, perhaps :file:`example.txt` contains this:: + + The ``example`` module + ====================== + + Using ``factorial`` + ------------------- + + This is an example text file in reStructuredText format. First import + ``factorial`` from the ``example`` module: + + >>> from example import factorial + + Now use it: + + >>> factorial(6) + 120 + +Running ``doctest.testfile("example.txt")`` then finds the error in this +documentation:: + + File "./example.txt", line 14, in example.txt + Failed example: + factorial(6) + Expected: + 120 + Got: + 720 + +As with :func:`testmod`, :func:`testfile` won't display anything unless an +example fails. If an example does fail, then the failing example(s) and the +cause(s) of the failure(s) are printed to stdout, using the same format as +:func:`testmod`. + +By default, :func:`testfile` looks for files in the calling module's directory. +See section :ref:`doctest-basic-api` for a description of the optional arguments +that can be used to tell it to look for files in other locations. + +Like :func:`testmod`, :func:`testfile`'s verbosity can be set with the +:option:`-v` command-line switch or with the optional keyword argument +*verbose*. + +Since Python 2.6, there is also a command line shortcut for running +:func:`testfile`. You can instruct the Python interpreter to run the doctest +module directly from the standard library and pass the file name(s) on the +command line:: + + python -m doctest -v example.txt + +Because the file name does not end with :file:`.py`, :mod:`doctest` infers that +it must be run with :func:`testfile`, not :func:`testmod`. + +For more information on :func:`testfile`, see section :ref:`doctest-basic-api`. + + +.. _doctest-how-it-works: + +How It Works +------------ + +This section examines in detail how doctest works: which docstrings it looks at, +how it finds interactive examples, what execution context it uses, how it +handles exceptions, and how option flags can be used to control its behavior. +This is the information that you need to know to write doctest examples; for +information about actually running doctest on these examples, see the following +sections. + + +.. _doctest-which-docstrings: + +Which Docstrings Are Examined? +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The module docstring, and all function, class and method docstrings are +searched. Objects imported into the module are not searched. + +In addition, if ``M.__test__`` exists and "is true", it must be a dict, and each +entry maps a (string) name to a function object, class object, or string. +Function and class object docstrings found from ``M.__test__`` are searched, and +strings are treated as if they were docstrings. In output, a key ``K`` in +``M.__test__`` appears with name :: + + .__test__.K + +Any classes found are recursively searched similarly, to test docstrings in +their contained methods and nested classes. + +.. versionchanged:: 2.4 + A "private name" concept is deprecated and no longer documented. + + +.. _doctest-finding-examples: + +How are Docstring Examples Recognized? +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +In most cases a copy-and-paste of an interactive console session works fine, but +doctest isn't trying to do an exact emulation of any specific Python shell. All +hard tab characters are expanded to spaces, using 8-column tab stops. If you +don't believe tabs should mean that, too bad: don't use hard tabs, or write +your own :class:`DocTestParser` class. + +.. versionchanged:: 2.4 + Expanding tabs to spaces is new; previous versions tried to preserve hard tabs, + with confusing results. + +:: + + >>> # comments are ignored + >>> x = 12 + >>> x + 12 + >>> if x == 13: + ... print "yes" + ... else: + ... print "no" + ... print "NO" + ... print "NO!!!" + ... + no + NO + NO!!! + >>> + +Any expected output must immediately follow the final ``'>>> '`` or ``'... '`` +line containing the code, and the expected output (if any) extends to the next +``'>>> '`` or all-whitespace line. + +The fine print: + +* Expected output cannot contain an all-whitespace line, since such a line is + taken to signal the end of expected output. If expected output does contain a + blank line, put ```` in your doctest example each place a blank line + is expected. + + .. versionchanged:: 2.4 + ```` was added; there was no way to use expected output containing + empty lines in previous versions. + +* Output to stdout is captured, but not output to stderr (exception tracebacks + are captured via a different means). + +* If you continue a line via backslashing in an interactive session, or for any + other reason use a backslash, you should use a raw docstring, which will + preserve your backslashes exactly as you type them:: + + >>> def f(x): + ... r'''Backslashes in a raw docstring: m\n''' + >>> print f.__doc__ + Backslashes in a raw docstring: m\n + + Otherwise, the backslash will be interpreted as part of the string. For example, + the "\\" above would be interpreted as a newline character. Alternatively, you + can double each backslash in the doctest version (and not use a raw string):: + + >>> def f(x): + ... '''Backslashes in a raw docstring: m\\n''' + >>> print f.__doc__ + Backslashes in a raw docstring: m\n + +* The starting column doesn't matter:: + + >>> assert "Easy!" + >>> import math + >>> math.floor(1.9) + 1.0 + + and as many leading whitespace characters are stripped from the expected output + as appeared in the initial ``'>>> '`` line that started the example. + + +.. _doctest-execution-context: + +What's the Execution Context? +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +By default, each time :mod:`doctest` finds a docstring to test, it uses a +*shallow copy* of :mod:`M`'s globals, so that running tests doesn't change the +module's real globals, and so that one test in :mod:`M` can't leave behind +crumbs that accidentally allow another test to work. This means examples can +freely use any names defined at top-level in :mod:`M`, and names defined earlier +in the docstring being run. Examples cannot see names defined in other +docstrings. + +You can force use of your own dict as the execution context by passing +``globs=your_dict`` to :func:`testmod` or :func:`testfile` instead. + + +.. _doctest-exceptions: + +What About Exceptions? +^^^^^^^^^^^^^^^^^^^^^^ + +No problem, provided that the traceback is the only output produced by the +example: just paste in the traceback. [#]_ Since tracebacks contain details +that are likely to change rapidly (for example, exact file paths and line +numbers), this is one case where doctest works hard to be flexible in what it +accepts. + +Simple example:: + + >>> [1, 2, 3].remove(42) + Traceback (most recent call last): + File "", line 1, in ? + ValueError: list.remove(x): x not in list + +That doctest succeeds if :exc:`ValueError` is raised, with the ``list.remove(x): +x not in list`` detail as shown. + +The expected output for an exception must start with a traceback header, which +may be either of the following two lines, indented the same as the first line of +the example:: + + Traceback (most recent call last): + Traceback (innermost last): + +The traceback header is followed by an optional traceback stack, whose contents +are ignored by doctest. The traceback stack is typically omitted, or copied +verbatim from an interactive session. + +The traceback stack is followed by the most interesting part: the line(s) +containing the exception type and detail. This is usually the last line of a +traceback, but can extend across multiple lines if the exception has a +multi-line detail:: + + >>> raise ValueError('multi\n line\ndetail') + Traceback (most recent call last): + File "", line 1, in ? + ValueError: multi + line + detail + +The last three lines (starting with :exc:`ValueError`) are compared against the +exception's type and detail, and the rest are ignored. + +Best practice is to omit the traceback stack, unless it adds significant +documentation value to the example. So the last example is probably better as:: + + >>> raise ValueError('multi\n line\ndetail') + Traceback (most recent call last): + ... + ValueError: multi + line + detail + +Note that tracebacks are treated very specially. In particular, in the +rewritten example, the use of ``...`` is independent of doctest's +:const:`ELLIPSIS` option. The ellipsis in that example could be left out, or +could just as well be three (or three hundred) commas or digits, or an indented +transcript of a Monty Python skit. + +Some details you should read once, but won't need to remember: + +* Doctest can't guess whether your expected output came from an exception + traceback or from ordinary printing. So, e.g., an example that expects + ``ValueError: 42 is prime`` will pass whether :exc:`ValueError` is actually + raised or if the example merely prints that traceback text. In practice, + ordinary output rarely begins with a traceback header line, so this doesn't + create real problems. + +* Each line of the traceback stack (if present) must be indented further than + the first line of the example, *or* start with a non-alphanumeric character. + The first line following the traceback header indented the same and starting + with an alphanumeric is taken to be the start of the exception detail. Of + course this does the right thing for genuine tracebacks. + +* When the :const:`IGNORE_EXCEPTION_DETAIL` doctest option is is specified, + everything following the leftmost colon is ignored. + +* The interactive shell omits the traceback header line for some + :exc:`SyntaxError`\ s. But doctest uses the traceback header line to + distinguish exceptions from non-exceptions. So in the rare case where you need + to test a :exc:`SyntaxError` that omits the traceback header, you will need to + manually add the traceback header line to your test example. + +* For some :exc:`SyntaxError`\ s, Python displays the character position of the + syntax error, using a ``^`` marker:: + + >>> 1 1 + File "", line 1 + 1 1 + ^ + SyntaxError: invalid syntax + + Since the lines showing the position of the error come before the exception type + and detail, they are not checked by doctest. For example, the following test + would pass, even though it puts the ``^`` marker in the wrong location:: + + >>> 1 1 + Traceback (most recent call last): + File "", line 1 + 1 1 + ^ + SyntaxError: invalid syntax + +.. versionchanged:: 2.4 + The ability to handle a multi-line exception detail, and the + :const:`IGNORE_EXCEPTION_DETAIL` doctest option, were added. + + +.. _doctest-options: + +Option Flags and Directives +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +A number of option flags control various aspects of doctest's behavior. +Symbolic names for the flags are supplied as module constants, which can be +or'ed together and passed to various functions. The names can also be used in +doctest directives (see below). + +The first group of options define test semantics, controlling aspects of how +doctest decides whether actual output matches an example's expected output: + + +.. data:: DONT_ACCEPT_TRUE_FOR_1 + + By default, if an expected output block contains just ``1``, an actual output + block containing just ``1`` or just ``True`` is considered to be a match, and + similarly for ``0`` versus ``False``. When :const:`DONT_ACCEPT_TRUE_FOR_1` is + specified, neither substitution is allowed. The default behavior caters to that + Python changed the return type of many functions from integer to boolean; + doctests expecting "little integer" output still work in these cases. This + option will probably go away, but not for several years. + + +.. data:: DONT_ACCEPT_BLANKLINE + + By default, if an expected output block contains a line containing only the + string ````, then that line will match a blank line in the actual + output. Because a genuinely blank line delimits the expected output, this is + the only way to communicate that a blank line is expected. When + :const:`DONT_ACCEPT_BLANKLINE` is specified, this substitution is not allowed. + + +.. data:: NORMALIZE_WHITESPACE + + When specified, all sequences of whitespace (blanks and newlines) are treated as + equal. Any sequence of whitespace within the expected output will match any + sequence of whitespace within the actual output. By default, whitespace must + match exactly. :const:`NORMALIZE_WHITESPACE` is especially useful when a line of + expected output is very long, and you want to wrap it across multiple lines in + your source. + + +.. data:: ELLIPSIS + + When specified, an ellipsis marker (``...``) in the expected output can match + any substring in the actual output. This includes substrings that span line + boundaries, and empty substrings, so it's best to keep usage of this simple. + Complicated uses can lead to the same kinds of "oops, it matched too much!" + surprises that ``.*`` is prone to in regular expressions. + + +.. data:: IGNORE_EXCEPTION_DETAIL + + When specified, an example that expects an exception passes if an exception of + the expected type is raised, even if the exception detail does not match. For + example, an example expecting ``ValueError: 42`` will pass if the actual + exception raised is ``ValueError: 3*14``, but will fail, e.g., if + :exc:`TypeError` is raised. + + Note that a similar effect can be obtained using :const:`ELLIPSIS`, and + :const:`IGNORE_EXCEPTION_DETAIL` may go away when Python releases prior to 2.4 + become uninteresting. Until then, :const:`IGNORE_EXCEPTION_DETAIL` is the only + clear way to write a doctest that doesn't care about the exception detail yet + continues to pass under Python releases prior to 2.4 (doctest directives appear + to be comments to them). For example, :: + + >>> (1, 2)[3] = 'moo' #doctest: +IGNORE_EXCEPTION_DETAIL + Traceback (most recent call last): + File "", line 1, in ? + TypeError: object doesn't support item assignment + + passes under Python 2.4 and Python 2.3. The detail changed in 2.4, to say "does + not" instead of "doesn't". + + +.. data:: SKIP + + When specified, do not run the example at all. This can be useful in contexts + where doctest examples serve as both documentation and test cases, and an + example should be included for documentation purposes, but should not be + checked. E.g., the example's output might be random; or the example might + depend on resources which would be unavailable to the test driver. + + The SKIP flag can also be used for temporarily "commenting out" examples. + + +.. data:: COMPARISON_FLAGS + + A bitmask or'ing together all the comparison flags above. + +The second group of options controls how test failures are reported: + + +.. data:: REPORT_UDIFF + + When specified, failures that involve multi-line expected and actual outputs are + displayed using a unified diff. + + +.. data:: REPORT_CDIFF + + When specified, failures that involve multi-line expected and actual outputs + will be displayed using a context diff. + + +.. data:: REPORT_NDIFF + + When specified, differences are computed by ``difflib.Differ``, using the same + algorithm as the popular :file:`ndiff.py` utility. This is the only method that + marks differences within lines as well as across lines. For example, if a line + of expected output contains digit ``1`` where actual output contains letter + ``l``, a line is inserted with a caret marking the mismatching column positions. + + +.. data:: REPORT_ONLY_FIRST_FAILURE + + When specified, display the first failing example in each doctest, but suppress + output for all remaining examples. This will prevent doctest from reporting + correct examples that break because of earlier failures; but it might also hide + incorrect examples that fail independently of the first failure. When + :const:`REPORT_ONLY_FIRST_FAILURE` is specified, the remaining examples are + still run, and still count towards the total number of failures reported; only + the output is suppressed. + + +.. data:: REPORTING_FLAGS + + A bitmask or'ing together all the reporting flags above. + +"Doctest directives" may be used to modify the option flags for individual +examples. Doctest directives are expressed as a special Python comment +following an example's source code: + +.. productionlist:: doctest + directive: "#" "doctest:" `directive_options` + directive_options: `directive_option` ("," `directive_option`)\* + directive_option: `on_or_off` `directive_option_name` + on_or_off: "+" \| "-" + directive_option_name: "DONT_ACCEPT_BLANKLINE" \| "NORMALIZE_WHITESPACE" \| ... + +Whitespace is not allowed between the ``+`` or ``-`` and the directive option +name. The directive option name can be any of the option flag names explained +above. + +An example's doctest directives modify doctest's behavior for that single +example. Use ``+`` to enable the named behavior, or ``-`` to disable it. + +For example, this test passes:: + + >>> print range(20) #doctest: +NORMALIZE_WHITESPACE + [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, + 10, 11, 12, 13, 14, 15, 16, 17, 18, 19] + +Without the directive it would fail, both because the actual output doesn't have +two blanks before the single-digit list elements, and because the actual output +is on a single line. This test also passes, and also requires a directive to do +so:: + + >>> print range(20) # doctest:+ELLIPSIS + [0, 1, ..., 18, 19] + +Multiple directives can be used on a single physical line, separated by commas:: + + >>> print range(20) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE + [0, 1, ..., 18, 19] + +If multiple directive comments are used for a single example, then they are +combined:: + + >>> print range(20) # doctest: +ELLIPSIS + ... # doctest: +NORMALIZE_WHITESPACE + [0, 1, ..., 18, 19] + +As the previous example shows, you can add ``...`` lines to your example +containing only directives. This can be useful when an example is too long for +a directive to comfortably fit on the same line:: + + >>> print range(5) + range(10,20) + range(30,40) + range(50,60) + ... # doctest: +ELLIPSIS + [0, ..., 4, 10, ..., 19, 30, ..., 39, 50, ..., 59] + +Note that since all options are disabled by default, and directives apply only +to the example they appear in, enabling options (via ``+`` in a directive) is +usually the only meaningful choice. However, option flags can also be passed to +functions that run doctests, establishing different defaults. In such cases, +disabling an option via ``-`` in a directive can be useful. + +.. versionchanged:: 2.4 + Constants :const:`DONT_ACCEPT_BLANKLINE`, :const:`NORMALIZE_WHITESPACE`, + :const:`ELLIPSIS`, :const:`IGNORE_EXCEPTION_DETAIL`, :const:`REPORT_UDIFF`, + :const:`REPORT_CDIFF`, :const:`REPORT_NDIFF`, + :const:`REPORT_ONLY_FIRST_FAILURE`, :const:`COMPARISON_FLAGS` and + :const:`REPORTING_FLAGS` were added; by default ```` in expected + output matches an empty line in actual output; and doctest directives were + added. + +.. versionchanged:: 2.5 + Constant :const:`SKIP` was added. + +There's also a way to register new option flag names, although this isn't useful +unless you intend to extend :mod:`doctest` internals via subclassing: + + +.. function:: register_optionflag(name) + + Create a new option flag with a given name, and return the new flag's integer + value. :func:`register_optionflag` can be used when subclassing + :class:`OutputChecker` or :class:`DocTestRunner` to create new options that are + supported by your subclasses. :func:`register_optionflag` should always be + called using the following idiom:: + + MY_FLAG = register_optionflag('MY_FLAG') + + .. versionadded:: 2.4 + + +.. _doctest-warnings: + +Warnings +^^^^^^^^ + +:mod:`doctest` is serious about requiring exact matches in expected output. If +even a single character doesn't match, the test fails. This will probably +surprise you a few times, as you learn exactly what Python does and doesn't +guarantee about output. For example, when printing a dict, Python doesn't +guarantee that the key-value pairs will be printed in any particular order, so a +test like + +.. % Hey! What happened to Monty Python examples? +.. % Tim: ask Guido -- it's his example! + +:: + + >>> foo() + {"Hermione": "hippogryph", "Harry": "broomstick"} + +is vulnerable! One workaround is to do :: + + >>> foo() == {"Hermione": "hippogryph", "Harry": "broomstick"} + True + +instead. Another is to do :: + + >>> d = foo().items() + >>> d.sort() + >>> d + [('Harry', 'broomstick'), ('Hermione', 'hippogryph')] + +There are others, but you get the idea. + +Another bad idea is to print things that embed an object address, like :: + + >>> id(1.0) # certain to fail some of the time + 7948648 + >>> class C: pass + >>> C() # the default repr() for instances embeds an address + <__main__.C instance at 0x00AC18F0> + +The :const:`ELLIPSIS` directive gives a nice approach for the last example:: + + >>> C() #doctest: +ELLIPSIS + <__main__.C instance at 0x...> + +Floating-point numbers are also subject to small output variations across +platforms, because Python defers to the platform C library for float formatting, +and C libraries vary widely in quality here. :: + + >>> 1./7 # risky + 0.14285714285714285 + >>> print 1./7 # safer + 0.142857142857 + >>> print round(1./7, 6) # much safer + 0.142857 + +Numbers of the form ``I/2.**J`` are safe across all platforms, and I often +contrive doctest examples to produce numbers of that form:: + + >>> 3./4 # utterly safe + 0.75 + +Simple fractions are also easier for people to understand, and that makes for +better documentation. + + +.. _doctest-basic-api: + +Basic API +--------- + +The functions :func:`testmod` and :func:`testfile` provide a simple interface to +doctest that should be sufficient for most basic uses. For a less formal +introduction to these two functions, see sections :ref:`doctest-simple-testmod` +and :ref:`doctest-simple-testfile`. + + +.. function:: testfile(filename[, module_relative][, name][, package][, globs][, verbose][, report][, optionflags][, extraglobs][, raise_on_error][, parser][, encoding]) + + All arguments except *filename* are optional, and should be specified in keyword + form. + + Test examples in the file named *filename*. Return ``(failure_count, + test_count)``. + + Optional argument *module_relative* specifies how the filename should be + interpreted: + + * If *module_relative* is ``True`` (the default), then *filename* specifies an + OS-independent module-relative path. By default, this path is relative to the + calling module's directory; but if the *package* argument is specified, then it + is relative to that package. To ensure OS-independence, *filename* should use + ``/`` characters to separate path segments, and may not be an absolute path + (i.e., it may not begin with ``/``). + + * If *module_relative* is ``False``, then *filename* specifies an OS-specific + path. The path may be absolute or relative; relative paths are resolved with + respect to the current working directory. + + Optional argument *name* gives the name of the test; by default, or if ``None``, + ``os.path.basename(filename)`` is used. + + Optional argument *package* is a Python package or the name of a Python package + whose directory should be used as the base directory for a module-relative + filename. If no package is specified, then the calling module's directory is + used as the base directory for module-relative filenames. It is an error to + specify *package* if *module_relative* is ``False``. + + Optional argument *globs* gives a dict to be used as the globals when executing + examples. A new shallow copy of this dict is created for the doctest, so its + examples start with a clean slate. By default, or if ``None``, a new empty dict + is used. + + Optional argument *extraglobs* gives a dict merged into the globals used to + execute examples. This works like :meth:`dict.update`: if *globs* and + *extraglobs* have a common key, the associated value in *extraglobs* appears in + the combined dict. By default, or if ``None``, no extra globals are used. This + is an advanced feature that allows parameterization of doctests. For example, a + doctest can be written for a base class, using a generic name for the class, + then reused to test any number of subclasses by passing an *extraglobs* dict + mapping the generic name to the subclass to be tested. + + Optional argument *verbose* prints lots of stuff if true, and prints only + failures if false; by default, or if ``None``, it's true if and only if ``'-v'`` + is in ``sys.argv``. + + Optional argument *report* prints a summary at the end when true, else prints + nothing at the end. In verbose mode, the summary is detailed, else the summary + is very brief (in fact, empty if all tests passed). + + Optional argument *optionflags* or's together option flags. See section + :ref:`doctest-options`. + + Optional argument *raise_on_error* defaults to false. If true, an exception is + raised upon the first failure or unexpected exception in an example. This + allows failures to be post-mortem debugged. Default behavior is to continue + running examples. + + Optional argument *parser* specifies a :class:`DocTestParser` (or subclass) that + should be used to extract tests from the files. It defaults to a normal parser + (i.e., ``DocTestParser()``). + + Optional argument *encoding* specifies an encoding that should be used to + convert the file to unicode. + + .. versionadded:: 2.4 + + .. versionchanged:: 2.5 + The parameter *encoding* was added. + + +.. function:: testmod([m][, name][, globs][, verbose][, report][, optionflags][, extraglobs][, raise_on_error][, exclude_empty]) + + All arguments are optional, and all except for *m* should be specified in + keyword form. + + Test examples in docstrings in functions and classes reachable from module *m* + (or module :mod:`__main__` if *m* is not supplied or is ``None``), starting with + ``m.__doc__``. + + Also test examples reachable from dict ``m.__test__``, if it exists and is not + ``None``. ``m.__test__`` maps names (strings) to functions, classes and + strings; function and class docstrings are searched for examples; strings are + searched directly, as if they were docstrings. + + Only docstrings attached to objects belonging to module *m* are searched. + + Return ``(failure_count, test_count)``. + + Optional argument *name* gives the name of the module; by default, or if + ``None``, ``m.__name__`` is used. + + Optional argument *exclude_empty* defaults to false. If true, objects for which + no doctests are found are excluded from consideration. The default is a backward + compatibility hack, so that code still using :meth:`doctest.master.summarize` in + conjunction with :func:`testmod` continues to get output for objects with no + tests. The *exclude_empty* argument to the newer :class:`DocTestFinder` + constructor defaults to true. + + Optional arguments *extraglobs*, *verbose*, *report*, *optionflags*, + *raise_on_error*, and *globs* are the same as for function :func:`testfile` + above, except that *globs* defaults to ``m.__dict__``. + + .. versionchanged:: 2.3 + The parameter *optionflags* was added. + + .. versionchanged:: 2.4 + The parameters *extraglobs*, *raise_on_error* and *exclude_empty* were added. + + .. versionchanged:: 2.5 + The optional argument *isprivate*, deprecated in 2.4, was removed. + +There's also a function to run the doctests associated with a single object. +This function is provided for backward compatibility. There are no plans to +deprecate it, but it's rarely useful: + + +.. function:: run_docstring_examples(f, globs[, verbose][, name][, compileflags][, optionflags]) + + Test examples associated with object *f*; for example, *f* may be a module, + function, or class object. + + A shallow copy of dictionary argument *globs* is used for the execution context. + + Optional argument *name* is used in failure messages, and defaults to + ``"NoName"``. + + If optional argument *verbose* is true, output is generated even if there are no + failures. By default, output is generated only in case of an example failure. + + Optional argument *compileflags* gives the set of flags that should be used by + the Python compiler when running the examples. By default, or if ``None``, + flags are deduced corresponding to the set of future features found in *globs*. + + Optional argument *optionflags* works as for function :func:`testfile` above. + + +.. _doctest-unittest-api: + +Unittest API +------------ + +As your collection of doctest'ed modules grows, you'll want a way to run all +their doctests systematically. Prior to Python 2.4, :mod:`doctest` had a barely +documented :class:`Tester` class that supplied a rudimentary way to combine +doctests from multiple modules. :class:`Tester` was feeble, and in practice most +serious Python testing frameworks build on the :mod:`unittest` module, which +supplies many flexible ways to combine tests from multiple sources. So, in +Python 2.4, :mod:`doctest`'s :class:`Tester` class is deprecated, and +:mod:`doctest` provides two functions that can be used to create :mod:`unittest` +test suites from modules and text files containing doctests. These test suites +can then be run using :mod:`unittest` test runners:: + + import unittest + import doctest + import my_module_with_doctests, and_another + + suite = unittest.TestSuite() + for mod in my_module_with_doctests, and_another: + suite.addTest(doctest.DocTestSuite(mod)) + runner = unittest.TextTestRunner() + runner.run(suite) + +There are two main functions for creating :class:`unittest.TestSuite` instances +from text files and modules with doctests: + + +.. function:: DocFileSuite([module_relative][, package][, setUp][, tearDown][, globs][, optionflags][, parser][, encoding]) + + Convert doctest tests from one or more text files to a + :class:`unittest.TestSuite`. + + The returned :class:`unittest.TestSuite` is to be run by the unittest framework + and runs the interactive examples in each file. If an example in any file + fails, then the synthesized unit test fails, and a :exc:`failureException` + exception is raised showing the name of the file containing the test and a + (sometimes approximate) line number. + + Pass one or more paths (as strings) to text files to be examined. + + Options may be provided as keyword arguments: + + Optional argument *module_relative* specifies how the filenames in *paths* + should be interpreted: + + * If *module_relative* is ``True`` (the default), then each filename specifies + an OS-independent module-relative path. By default, this path is relative to + the calling module's directory; but if the *package* argument is specified, then + it is relative to that package. To ensure OS-independence, each filename should + use ``/`` characters to separate path segments, and may not be an absolute path + (i.e., it may not begin with ``/``). + + * If *module_relative* is ``False``, then each filename specifies an OS-specific + path. The path may be absolute or relative; relative paths are resolved with + respect to the current working directory. + + Optional argument *package* is a Python package or the name of a Python package + whose directory should be used as the base directory for module-relative + filenames. If no package is specified, then the calling module's directory is + used as the base directory for module-relative filenames. It is an error to + specify *package* if *module_relative* is ``False``. + + Optional argument *setUp* specifies a set-up function for the test suite. This + is called before running the tests in each file. The *setUp* function will be + passed a :class:`DocTest` object. The setUp function can access the test + globals as the *globs* attribute of the test passed. + + Optional argument *tearDown* specifies a tear-down function for the test suite. + This is called after running the tests in each file. The *tearDown* function + will be passed a :class:`DocTest` object. The setUp function can access the + test globals as the *globs* attribute of the test passed. + + Optional argument *globs* is a dictionary containing the initial global + variables for the tests. A new copy of this dictionary is created for each + test. By default, *globs* is a new empty dictionary. + + Optional argument *optionflags* specifies the default doctest options for the + tests, created by or-ing together individual option flags. See section + :ref:`doctest-options`. See function :func:`set_unittest_reportflags` below for + a better way to set reporting options. + + Optional argument *parser* specifies a :class:`DocTestParser` (or subclass) that + should be used to extract tests from the files. It defaults to a normal parser + (i.e., ``DocTestParser()``). + + Optional argument *encoding* specifies an encoding that should be used to + convert the file to unicode. + + .. versionadded:: 2.4 + + .. versionchanged:: 2.5 + The global ``__file__`` was added to the globals provided to doctests loaded + from a text file using :func:`DocFileSuite`. + + .. versionchanged:: 2.5 + The parameter *encoding* was added. + + +.. function:: DocTestSuite([module][, globs][, extraglobs][, test_finder][, setUp][, tearDown][, checker]) + + Convert doctest tests for a module to a :class:`unittest.TestSuite`. + + The returned :class:`unittest.TestSuite` is to be run by the unittest framework + and runs each doctest in the module. If any of the doctests fail, then the + synthesized unit test fails, and a :exc:`failureException` exception is raised + showing the name of the file containing the test and a (sometimes approximate) + line number. + + Optional argument *module* provides the module to be tested. It can be a module + object or a (possibly dotted) module name. If not specified, the module calling + this function is used. + + Optional argument *globs* is a dictionary containing the initial global + variables for the tests. A new copy of this dictionary is created for each + test. By default, *globs* is a new empty dictionary. + + Optional argument *extraglobs* specifies an extra set of global variables, which + is merged into *globs*. By default, no extra globals are used. + + Optional argument *test_finder* is the :class:`DocTestFinder` object (or a + drop-in replacement) that is used to extract doctests from the module. + + Optional arguments *setUp*, *tearDown*, and *optionflags* are the same as for + function :func:`DocFileSuite` above. + + .. versionadded:: 2.3 + + .. versionchanged:: 2.4 + The parameters *globs*, *extraglobs*, *test_finder*, *setUp*, *tearDown*, and + *optionflags* were added; this function now uses the same search technique as + :func:`testmod`. + +Under the covers, :func:`DocTestSuite` creates a :class:`unittest.TestSuite` out +of :class:`doctest.DocTestCase` instances, and :class:`DocTestCase` is a +subclass of :class:`unittest.TestCase`. :class:`DocTestCase` isn't documented +here (it's an internal detail), but studying its code can answer questions about +the exact details of :mod:`unittest` integration. + +Similarly, :func:`DocFileSuite` creates a :class:`unittest.TestSuite` out of +:class:`doctest.DocFileCase` instances, and :class:`DocFileCase` is a subclass +of :class:`DocTestCase`. + +So both ways of creating a :class:`unittest.TestSuite` run instances of +:class:`DocTestCase`. This is important for a subtle reason: when you run +:mod:`doctest` functions yourself, you can control the :mod:`doctest` options in +use directly, by passing option flags to :mod:`doctest` functions. However, if +you're writing a :mod:`unittest` framework, :mod:`unittest` ultimately controls +when and how tests get run. The framework author typically wants to control +:mod:`doctest` reporting options (perhaps, e.g., specified by command line +options), but there's no way to pass options through :mod:`unittest` to +:mod:`doctest` test runners. + +For this reason, :mod:`doctest` also supports a notion of :mod:`doctest` +reporting flags specific to :mod:`unittest` support, via this function: + + +.. function:: set_unittest_reportflags(flags) + + Set the :mod:`doctest` reporting flags to use. + + Argument *flags* or's together option flags. See section + :ref:`doctest-options`. Only "reporting flags" can be used. + + This is a module-global setting, and affects all future doctests run by module + :mod:`unittest`: the :meth:`runTest` method of :class:`DocTestCase` looks at + the option flags specified for the test case when the :class:`DocTestCase` + instance was constructed. If no reporting flags were specified (which is the + typical and expected case), :mod:`doctest`'s :mod:`unittest` reporting flags are + or'ed into the option flags, and the option flags so augmented are passed to the + :class:`DocTestRunner` instance created to run the doctest. If any reporting + flags were specified when the :class:`DocTestCase` instance was constructed, + :mod:`doctest`'s :mod:`unittest` reporting flags are ignored. + + The value of the :mod:`unittest` reporting flags in effect before the function + was called is returned by the function. + + .. versionadded:: 2.4 + + +.. _doctest-advanced-api: + +Advanced API +------------ + +The basic API is a simple wrapper that's intended to make doctest easy to use. +It is fairly flexible, and should meet most users' needs; however, if you +require more fine-grained control over testing, or wish to extend doctest's +capabilities, then you should use the advanced API. + +The advanced API revolves around two container classes, which are used to store +the interactive examples extracted from doctest cases: + +* :class:`Example`: A single python statement, paired with its expected output. + +* :class:`DocTest`: A collection of :class:`Example`\ s, typically extracted + from a single docstring or text file. + +Additional processing classes are defined to find, parse, and run, and check +doctest examples: + +* :class:`DocTestFinder`: Finds all docstrings in a given module, and uses a + :class:`DocTestParser` to create a :class:`DocTest` from every docstring that + contains interactive examples. + +* :class:`DocTestParser`: Creates a :class:`DocTest` object from a string (such + as an object's docstring). + +* :class:`DocTestRunner`: Executes the examples in a :class:`DocTest`, and uses + an :class:`OutputChecker` to verify their output. + +* :class:`OutputChecker`: Compares the actual output from a doctest example with + the expected output, and decides whether they match. + +The relationships among these processing classes are summarized in the following +diagram:: + + list of: + +------+ +---------+ + |module| --DocTestFinder-> | DocTest | --DocTestRunner-> results + +------+ | ^ +---------+ | ^ (printed) + | | | Example | | | + v | | ... | v | + DocTestParser | Example | OutputChecker + +---------+ + + +.. _doctest-doctest: + +DocTest Objects +^^^^^^^^^^^^^^^ + + +.. class:: DocTest(examples, globs, name, filename, lineno, docstring) + + A collection of doctest examples that should be run in a single namespace. The + constructor arguments are used to initialize the member variables of the same + names. + + .. versionadded:: 2.4 + +:class:`DocTest` defines the following member variables. They are initialized +by the constructor, and should not be modified directly. + + +.. attribute:: DocTest.examples + + A list of :class:`Example` objects encoding the individual interactive Python + examples that should be run by this test. + + +.. attribute:: DocTest.globs + + The namespace (aka globals) that the examples should be run in. This is a + dictionary mapping names to values. Any changes to the namespace made by the + examples (such as binding new variables) will be reflected in :attr:`globs` + after the test is run. + + +.. attribute:: DocTest.name + + A string name identifying the :class:`DocTest`. Typically, this is the name of + the object or file that the test was extracted from. + + +.. attribute:: DocTest.filename + + The name of the file that this :class:`DocTest` was extracted from; or ``None`` + if the filename is unknown, or if the :class:`DocTest` was not extracted from a + file. + + +.. attribute:: DocTest.lineno + + The line number within :attr:`filename` where this :class:`DocTest` begins, or + ``None`` if the line number is unavailable. This line number is zero-based with + respect to the beginning of the file. + + +.. attribute:: DocTest.docstring + + The string that the test was extracted from, or 'None' if the string is + unavailable, or if the test was not extracted from a string. + + +.. _doctest-example: + +Example Objects +^^^^^^^^^^^^^^^ + + +.. class:: Example(source, want[, exc_msg][, lineno][, indent][, options]) + + A single interactive example, consisting of a Python statement and its expected + output. The constructor arguments are used to initialize the member variables + of the same names. + + .. versionadded:: 2.4 + +:class:`Example` defines the following member variables. They are initialized +by the constructor, and should not be modified directly. + + +.. attribute:: Example.source + + A string containing the example's source code. This source code consists of a + single Python statement, and always ends with a newline; the constructor adds a + newline when necessary. + + +.. attribute:: Example.want + + The expected output from running the example's source code (either from stdout, + or a traceback in case of exception). :attr:`want` ends with a newline unless + no output is expected, in which case it's an empty string. The constructor adds + a newline when necessary. + + +.. attribute:: Example.exc_msg + + The exception message generated by the example, if the example is expected to + generate an exception; or ``None`` if it is not expected to generate an + exception. This exception message is compared against the return value of + :func:`traceback.format_exception_only`. :attr:`exc_msg` ends with a newline + unless it's ``None``. The constructor adds a newline if needed. + + +.. attribute:: Example.lineno + + The line number within the string containing this example where the example + begins. This line number is zero-based with respect to the beginning of the + containing string. + + +.. attribute:: Example.indent + + The example's indentation in the containing string, i.e., the number of space + characters that precede the example's first prompt. + + +.. attribute:: Example.options + + A dictionary mapping from option flags to ``True`` or ``False``, which is used + to override default options for this example. Any option flags not contained in + this dictionary are left at their default value (as specified by the + :class:`DocTestRunner`'s :attr:`optionflags`). By default, no options are set. + + +.. _doctest-doctestfinder: + +DocTestFinder objects +^^^^^^^^^^^^^^^^^^^^^ + + +.. class:: DocTestFinder([verbose][, parser][, recurse][, exclude_empty]) + + A processing class used to extract the :class:`DocTest`\ s that are relevant to + a given object, from its docstring and the docstrings of its contained objects. + :class:`DocTest`\ s can currently be extracted from the following object types: + modules, functions, classes, methods, staticmethods, classmethods, and + properties. + + The optional argument *verbose* can be used to display the objects searched by + the finder. It defaults to ``False`` (no output). + + The optional argument *parser* specifies the :class:`DocTestParser` object (or a + drop-in replacement) that is used to extract doctests from docstrings. + + If the optional argument *recurse* is false, then :meth:`DocTestFinder.find` + will only examine the given object, and not any contained objects. + + If the optional argument *exclude_empty* is false, then + :meth:`DocTestFinder.find` will include tests for objects with empty docstrings. + + .. versionadded:: 2.4 + +:class:`DocTestFinder` defines the following method: + + +.. method:: DocTestFinder.find(obj[, name][, module][, globs][, extraglobs]) + + Return a list of the :class:`DocTest`\ s that are defined by *obj*'s docstring, + or by any of its contained objects' docstrings. + + The optional argument *name* specifies the object's name; this name will be used + to construct names for the returned :class:`DocTest`\ s. If *name* is not + specified, then ``obj.__name__`` is used. + + The optional parameter *module* is the module that contains the given object. + If the module is not specified or is None, then the test finder will attempt to + automatically determine the correct module. The object's module is used: + + * As a default namespace, if *globs* is not specified. + + * To prevent the DocTestFinder from extracting DocTests from objects that are + imported from other modules. (Contained objects with modules other than + *module* are ignored.) + + * To find the name of the file containing the object. + + * To help find the line number of the object within its file. + + If *module* is ``False``, no attempt to find the module will be made. This is + obscure, of use mostly in testing doctest itself: if *module* is ``False``, or + is ``None`` but cannot be found automatically, then all objects are considered + to belong to the (non-existent) module, so all contained objects will + (recursively) be searched for doctests. + + The globals for each :class:`DocTest` is formed by combining *globs* and + *extraglobs* (bindings in *extraglobs* override bindings in *globs*). A new + shallow copy of the globals dictionary is created for each :class:`DocTest`. If + *globs* is not specified, then it defaults to the module's *__dict__*, if + specified, or ``{}`` otherwise. If *extraglobs* is not specified, then it + defaults to ``{}``. + + +.. _doctest-doctestparser: + +DocTestParser objects +^^^^^^^^^^^^^^^^^^^^^ + + +.. class:: DocTestParser() + + A processing class used to extract interactive examples from a string, and use + them to create a :class:`DocTest` object. + + .. versionadded:: 2.4 + +:class:`DocTestParser` defines the following methods: + + +.. method:: DocTestParser.get_doctest(string, globs, name, filename, lineno) + + Extract all doctest examples from the given string, and collect them into a + :class:`DocTest` object. + + *globs*, *name*, *filename*, and *lineno* are attributes for the new + :class:`DocTest` object. See the documentation for :class:`DocTest` for more + information. + + +.. method:: DocTestParser.get_examples(string[, name]) + + Extract all doctest examples from the given string, and return them as a list of + :class:`Example` objects. Line numbers are 0-based. The optional argument + *name* is a name identifying this string, and is only used for error messages. + + +.. method:: DocTestParser.parse(string[, name]) + + Divide the given string into examples and intervening text, and return them as a + list of alternating :class:`Example`\ s and strings. Line numbers for the + :class:`Example`\ s are 0-based. The optional argument *name* is a name + identifying this string, and is only used for error messages. + + +.. _doctest-doctestrunner: + +DocTestRunner objects +^^^^^^^^^^^^^^^^^^^^^ + + +.. class:: DocTestRunner([checker][, verbose][, optionflags]) + + A processing class used to execute and verify the interactive examples in a + :class:`DocTest`. + + The comparison between expected outputs and actual outputs is done by an + :class:`OutputChecker`. This comparison may be customized with a number of + option flags; see section :ref:`doctest-options` for more information. If the + option flags are insufficient, then the comparison may also be customized by + passing a subclass of :class:`OutputChecker` to the constructor. + + The test runner's display output can be controlled in two ways. First, an output + function can be passed to :meth:`TestRunner.run`; this function will be called + with strings that should be displayed. It defaults to ``sys.stdout.write``. If + capturing the output is not sufficient, then the display output can be also + customized by subclassing DocTestRunner, and overriding the methods + :meth:`report_start`, :meth:`report_success`, + :meth:`report_unexpected_exception`, and :meth:`report_failure`. + + The optional keyword argument *checker* specifies the :class:`OutputChecker` + object (or drop-in replacement) that should be used to compare the expected + outputs to the actual outputs of doctest examples. + + The optional keyword argument *verbose* controls the :class:`DocTestRunner`'s + verbosity. If *verbose* is ``True``, then information is printed about each + example, as it is run. If *verbose* is ``False``, then only failures are + printed. If *verbose* is unspecified, or ``None``, then verbose output is used + iff the command-line switch :option:`-v` is used. + + The optional keyword argument *optionflags* can be used to control how the test + runner compares expected output to actual output, and how it displays failures. + For more information, see section :ref:`doctest-options`. + + .. versionadded:: 2.4 + +:class:`DocTestParser` defines the following methods: + + +.. method:: DocTestRunner.report_start(out, test, example) + + Report that the test runner is about to process the given example. This method + is provided to allow subclasses of :class:`DocTestRunner` to customize their + output; it should not be called directly. + + *example* is the example about to be processed. *test* is the test containing + *example*. *out* is the output function that was passed to + :meth:`DocTestRunner.run`. + + +.. method:: DocTestRunner.report_success(out, test, example, got) + + Report that the given example ran successfully. This method is provided to + allow subclasses of :class:`DocTestRunner` to customize their output; it should + not be called directly. + + *example* is the example about to be processed. *got* is the actual output from + the example. *test* is the test containing *example*. *out* is the output + function that was passed to :meth:`DocTestRunner.run`. + + +.. method:: DocTestRunner.report_failure(out, test, example, got) + + Report that the given example failed. This method is provided to allow + subclasses of :class:`DocTestRunner` to customize their output; it should not be + called directly. + + *example* is the example about to be processed. *got* is the actual output from + the example. *test* is the test containing *example*. *out* is the output + function that was passed to :meth:`DocTestRunner.run`. + + +.. method:: DocTestRunner.report_unexpected_exception(out, test, example, exc_info) + + Report that the given example raised an unexpected exception. This method is + provided to allow subclasses of :class:`DocTestRunner` to customize their + output; it should not be called directly. + + *example* is the example about to be processed. *exc_info* is a tuple containing + information about the unexpected exception (as returned by + :func:`sys.exc_info`). *test* is the test containing *example*. *out* is the + output function that was passed to :meth:`DocTestRunner.run`. + + +.. method:: DocTestRunner.run(test[, compileflags][, out][, clear_globs]) + + Run the examples in *test* (a :class:`DocTest` object), and display the results + using the writer function *out*. + + The examples are run in the namespace ``test.globs``. If *clear_globs* is true + (the default), then this namespace will be cleared after the test runs, to help + with garbage collection. If you would like to examine the namespace after the + test completes, then use *clear_globs=False*. + + *compileflags* gives the set of flags that should be used by the Python compiler + when running the examples. If not specified, then it will default to the set of + future-import flags that apply to *globs*. + + The output of each example is checked using the :class:`DocTestRunner`'s output + checker, and the results are formatted by the :meth:`DocTestRunner.report_\*` + methods. + + +.. method:: DocTestRunner.summarize([verbose]) + + Print a summary of all the test cases that have been run by this DocTestRunner, + and return a tuple ``(failure_count, test_count)``. + + The optional *verbose* argument controls how detailed the summary is. If the + verbosity is not specified, then the :class:`DocTestRunner`'s verbosity is used. + + +.. _doctest-outputchecker: + +OutputChecker objects +^^^^^^^^^^^^^^^^^^^^^ + + +.. class:: OutputChecker() + + A class used to check the whether the actual output from a doctest example + matches the expected output. :class:`OutputChecker` defines two methods: + :meth:`check_output`, which compares a given pair of outputs, and returns true + if they match; and :meth:`output_difference`, which returns a string describing + the differences between two outputs. + + .. versionadded:: 2.4 + +:class:`OutputChecker` defines the following methods: + + +.. method:: OutputChecker.check_output(want, got, optionflags) + + Return ``True`` iff the actual output from an example (*got*) matches the + expected output (*want*). These strings are always considered to match if they + are identical; but depending on what option flags the test runner is using, + several non-exact match types are also possible. See section + :ref:`doctest-options` for more information about option flags. + + +.. method:: OutputChecker.output_difference(example, got, optionflags) + + Return a string describing the differences between the expected output for a + given example (*example*) and the actual output (*got*). *optionflags* is the + set of option flags used to compare *want* and *got*. + + +.. _doctest-debugging: + +Debugging +--------- + +Doctest provides several mechanisms for debugging doctest examples: + +* Several functions convert doctests to executable Python programs, which can be + run under the Python debugger, :mod:`pdb`. + +* The :class:`DebugRunner` class is a subclass of :class:`DocTestRunner` that + raises an exception for the first failing example, containing information about + that example. This information can be used to perform post-mortem debugging on + the example. + +* The :mod:`unittest` cases generated by :func:`DocTestSuite` support the + :meth:`debug` method defined by :class:`unittest.TestCase`. + +* You can add a call to :func:`pdb.set_trace` in a doctest example, and you'll + drop into the Python debugger when that line is executed. Then you can inspect + current values of variables, and so on. For example, suppose :file:`a.py` + contains just this module docstring:: + + """ + >>> def f(x): + ... g(x*2) + >>> def g(x): + ... print x+3 + ... import pdb; pdb.set_trace() + >>> f(3) + 9 + """ + + Then an interactive Python session may look like this:: + + >>> import a, doctest + >>> doctest.testmod(a) + --Return-- + > (3)g()->None + -> import pdb; pdb.set_trace() + (Pdb) list + 1 def g(x): + 2 print x+3 + 3 -> import pdb; pdb.set_trace() + [EOF] + (Pdb) print x + 6 + (Pdb) step + --Return-- + > (2)f()->None + -> g(x*2) + (Pdb) list + 1 def f(x): + 2 -> g(x*2) + [EOF] + (Pdb) print x + 3 + (Pdb) step + --Return-- + > (1)?()->None + -> f(3) + (Pdb) cont + (0, 3) + >>> + + .. versionchanged:: 2.4 + The ability to use :func:`pdb.set_trace` usefully inside doctests was added. + +Functions that convert doctests to Python code, and possibly run the synthesized +code under the debugger: + + +.. function:: script_from_examples(s) + + Convert text with examples to a script. + + Argument *s* is a string containing doctest examples. The string is converted + to a Python script, where doctest examples in *s* are converted to regular code, + and everything else is converted to Python comments. The generated script is + returned as a string. For example, :: + + import doctest + print doctest.script_from_examples(r""" + Set x and y to 1 and 2. + >>> x, y = 1, 2 + + Print their sum: + >>> print x+y + 3 + """) + + displays:: + + # Set x and y to 1 and 2. + x, y = 1, 2 + # + # Print their sum: + print x+y + # Expected: + ## 3 + + This function is used internally by other functions (see below), but can also be + useful when you want to transform an interactive Python session into a Python + script. + + .. versionadded:: 2.4 + + +.. function:: testsource(module, name) + + Convert the doctest for an object to a script. + + Argument *module* is a module object, or dotted name of a module, containing the + object whose doctests are of interest. Argument *name* is the name (within the + module) of the object with the doctests of interest. The result is a string, + containing the object's docstring converted to a Python script, as described for + :func:`script_from_examples` above. For example, if module :file:`a.py` + contains a top-level function :func:`f`, then :: + + import a, doctest + print doctest.testsource(a, "a.f") + + prints a script version of function :func:`f`'s docstring, with doctests + converted to code, and the rest placed in comments. + + .. versionadded:: 2.3 + + +.. function:: debug(module, name[, pm]) + + Debug the doctests for an object. + + The *module* and *name* arguments are the same as for function + :func:`testsource` above. The synthesized Python script for the named object's + docstring is written to a temporary file, and then that file is run under the + control of the Python debugger, :mod:`pdb`. + + A shallow copy of ``module.__dict__`` is used for both local and global + execution context. + + Optional argument *pm* controls whether post-mortem debugging is used. If *pm* + has a true value, the script file is run directly, and the debugger gets + involved only if the script terminates via raising an unhandled exception. If + it does, then post-mortem debugging is invoked, via :func:`pdb.post_mortem`, + passing the traceback object from the unhandled exception. If *pm* is not + specified, or is false, the script is run under the debugger from the start, via + passing an appropriate :func:`exec` call to :func:`pdb.run`. + + .. versionadded:: 2.3 + + .. versionchanged:: 2.4 + The *pm* argument was added. + + +.. function:: debug_src(src[, pm][, globs]) + + Debug the doctests in a string. + + This is like function :func:`debug` above, except that a string containing + doctest examples is specified directly, via the *src* argument. + + Optional argument *pm* has the same meaning as in function :func:`debug` above. + + Optional argument *globs* gives a dictionary to use as both local and global + execution context. If not specified, or ``None``, an empty dictionary is used. + If specified, a shallow copy of the dictionary is used. + + .. versionadded:: 2.4 + +The :class:`DebugRunner` class, and the special exceptions it may raise, are of +most interest to testing framework authors, and will only be sketched here. See +the source code, and especially :class:`DebugRunner`'s docstring (which is a +doctest!) for more details: + + +.. class:: DebugRunner([checker][, verbose][, optionflags]) + + A subclass of :class:`DocTestRunner` that raises an exception as soon as a + failure is encountered. If an unexpected exception occurs, an + :exc:`UnexpectedException` exception is raised, containing the test, the + example, and the original exception. If the output doesn't match, then a + :exc:`DocTestFailure` exception is raised, containing the test, the example, and + the actual output. + + For information about the constructor parameters and methods, see the + documentation for :class:`DocTestRunner` in section :ref:`doctest-advanced-api`. + +There are two exceptions that may be raised by :class:`DebugRunner` instances: + + +.. exception:: DocTestFailure(test, example, got) + + An exception thrown by :class:`DocTestRunner` to signal that a doctest example's + actual output did not match its expected output. The constructor arguments are + used to initialize the member variables of the same names. + +:exc:`DocTestFailure` defines the following member variables: + + +.. attribute:: DocTestFailure.test + + The :class:`DocTest` object that was being run when the example failed. + + +.. attribute:: DocTestFailure.example + + The :class:`Example` that failed. + + +.. attribute:: DocTestFailure.got + + The example's actual output. + + +.. exception:: UnexpectedException(test, example, exc_info) + + An exception thrown by :class:`DocTestRunner` to signal that a doctest example + raised an unexpected exception. The constructor arguments are used to + initialize the member variables of the same names. + +:exc:`UnexpectedException` defines the following member variables: + + +.. attribute:: UnexpectedException.test + + The :class:`DocTest` object that was being run when the example failed. + + +.. attribute:: UnexpectedException.example + + The :class:`Example` that failed. + + +.. attribute:: UnexpectedException.exc_info + + A tuple containing information about the unexpected exception, as returned by + :func:`sys.exc_info`. + + +.. _doctest-soapbox: + +Soapbox +------- + +As mentioned in the introduction, :mod:`doctest` has grown to have three primary +uses: + +#. Checking examples in docstrings. + +#. Regression testing. + +#. Executable documentation / literate testing. + +These uses have different requirements, and it is important to distinguish them. +In particular, filling your docstrings with obscure test cases makes for bad +documentation. + +When writing a docstring, choose docstring examples with care. There's an art to +this that needs to be learned---it may not be natural at first. Examples should +add genuine value to the documentation. A good example can often be worth many +words. If done with care, the examples will be invaluable for your users, and +will pay back the time it takes to collect them many times over as the years go +by and things change. I'm still amazed at how often one of my :mod:`doctest` +examples stops working after a "harmless" change. + +Doctest also makes an excellent tool for regression testing, especially if you +don't skimp on explanatory text. By interleaving prose and examples, it becomes +much easier to keep track of what's actually being tested, and why. When a test +fails, good prose can make it much easier to figure out what the problem is, and +how it should be fixed. It's true that you could write extensive comments in +code-based testing, but few programmers do. Many have found that using doctest +approaches instead leads to much clearer tests. Perhaps this is simply because +doctest makes writing prose a little easier than writing code, while writing +comments in code is a little harder. I think it goes deeper than just that: +the natural attitude when writing a doctest-based test is that you want to +explain the fine points of your software, and illustrate them with examples. +This in turn naturally leads to test files that start with the simplest +features, and logically progress to complications and edge cases. A coherent +narrative is the result, instead of a collection of isolated functions that test +isolated bits of functionality seemingly at random. It's a different attitude, +and produces different results, blurring the distinction between testing and +explaining. + +Regression testing is best confined to dedicated objects or files. There are +several options for organizing tests: + +* Write text files containing test cases as interactive examples, and test the + files using :func:`testfile` or :func:`DocFileSuite`. This is recommended, + although is easiest to do for new projects, designed from the start to use + doctest. + +* Define functions named ``_regrtest_topic`` that consist of single docstrings, + containing test cases for the named topics. These functions can be included in + the same file as the module, or separated out into a separate test file. + +* Define a ``__test__`` dictionary mapping from regression test topics to + docstrings containing test cases. + +.. rubric:: Footnotes + +.. [#] Examples containing both expected output and an exception are not supported. + Trying to guess where one ends and the other begins is too error-prone, and that + also makes for a confusing test. + diff --git a/Doc/library/docxmlrpcserver.rst b/Doc/library/docxmlrpcserver.rst new file mode 100644 index 0000000..958ea95 --- /dev/null +++ b/Doc/library/docxmlrpcserver.rst @@ -0,0 +1,97 @@ + +:mod:`DocXMLRPCServer` --- Self-documenting XML-RPC server +========================================================== + +.. module:: DocXMLRPCServer + :synopsis: Self-documenting XML-RPC server implementation. +.. moduleauthor:: Brian Quinlan +.. sectionauthor:: Brian Quinlan + + +.. versionadded:: 2.3 + +The :mod:`DocXMLRPCServer` module extends the classes found in +:mod:`SimpleXMLRPCServer` to serve HTML documentation in response to HTTP GET +requests. Servers can either be free standing, using :class:`DocXMLRPCServer`, +or embedded in a CGI environment, using :class:`DocCGIXMLRPCRequestHandler`. + + +.. class:: DocXMLRPCServer(addr[, requestHandler[, logRequests[, allow_none[, encoding[, bind_and_activate]]]]]) + + Create a new server instance. All parameters have the same meaning as for + :class:`SimpleXMLRPCServer.SimpleXMLRPCServer`; *requestHandler* defaults to + :class:`DocXMLRPCRequestHandler`. + + +.. class:: DocCGIXMLRPCRequestHandler() + + Create a new instance to handle XML-RPC requests in a CGI environment. + + +.. class:: DocXMLRPCRequestHandler() + + Create a new request handler instance. This request handler supports XML-RPC + POST requests, documentation GET requests, and modifies logging so that the + *logRequests* parameter to the :class:`DocXMLRPCServer` constructor parameter is + honored. + + +.. _doc-xmlrpc-servers: + +DocXMLRPCServer Objects +----------------------- + +The :class:`DocXMLRPCServer` class is derived from +:class:`SimpleXMLRPCServer.SimpleXMLRPCServer` and provides a means of creating +self-documenting, stand alone XML-RPC servers. HTTP POST requests are handled as +XML-RPC method calls. HTTP GET requests are handled by generating pydoc-style +HTML documentation. This allows a server to provide its own web-based +documentation. + + +.. method:: DocXMLRPCServer.set_server_title(server_title) + + Set the title used in the generated HTML documentation. This title will be used + inside the HTML "title" element. + + +.. method:: DocXMLRPCServer.set_server_name(server_name) + + Set the name used in the generated HTML documentation. This name will appear at + the top of the generated documentation inside a "h1" element. + + +.. method:: DocXMLRPCServer.set_server_documentation(server_documentation) + + Set the description used in the generated HTML documentation. This description + will appear as a paragraph, below the server name, in the documentation. + + +DocCGIXMLRPCRequestHandler +-------------------------- + +The :class:`DocCGIXMLRPCRequestHandler` class is derived from +:class:`SimpleXMLRPCServer.CGIXMLRPCRequestHandler` and provides a means of +creating self-documenting, XML-RPC CGI scripts. HTTP POST requests are handled +as XML-RPC method calls. HTTP GET requests are handled by generating pydoc-style +HTML documentation. This allows a server to provide its own web-based +documentation. + + +.. method:: DocCGIXMLRPCRequestHandler.set_server_title(server_title) + + Set the title used in the generated HTML documentation. This title will be used + inside the HTML "title" element. + + +.. method:: DocCGIXMLRPCRequestHandler.set_server_name(server_name) + + Set the name used in the generated HTML documentation. This name will appear at + the top of the generated documentation inside a "h1" element. + + +.. method:: DocCGIXMLRPCRequestHandler.set_server_documentation(server_documentation) + + Set the description used in the generated HTML documentation. This description + will appear as a paragraph, below the server name, in the documentation. + diff --git a/Doc/library/dumbdbm.rst b/Doc/library/dumbdbm.rst new file mode 100644 index 0000000..3db9fda --- /dev/null +++ b/Doc/library/dumbdbm.rst @@ -0,0 +1,81 @@ + +:mod:`dumbdbm` --- Portable DBM implementation +============================================== + +.. module:: dumbdbm + :synopsis: Portable implementation of the simple DBM interface. + + +.. index:: single: databases + +.. note:: + + The :mod:`dumbdbm` module is intended as a last resort fallback for the + :mod:`anydbm` module when no more robust module is available. The :mod:`dumbdbm` + module is not written for speed and is not nearly as heavily used as the other + database modules. + +The :mod:`dumbdbm` module provides a persistent dictionary-like interface which +is written entirely in Python. Unlike other modules such as :mod:`gdbm` and +:mod:`bsddb`, no external library is required. As with other persistent +mappings, the keys and values must always be strings. + +The module defines the following: + + +.. exception:: error + + Raised on dumbdbm-specific errors, such as I/O errors. :exc:`KeyError` is + raised for general mapping errors like specifying an incorrect key. + + +.. function:: open(filename[, flag[, mode]]) + + Open a dumbdbm database and return a dumbdbm object. The *filename* argument is + the basename of the database file (without any specific extensions). When a + dumbdbm database is created, files with :file:`.dat` and :file:`.dir` extensions + are created. + + The optional *flag* argument is currently ignored; the database is always opened + for update, and will be created if it does not exist. + + The optional *mode* argument is the Unix mode of the file, used only when the + database has to be created. It defaults to octal ``0666`` (and will be modified + by the prevailing umask). + + .. versionchanged:: 2.2 + The *mode* argument was ignored in earlier versions. + + +.. seealso:: + + Module :mod:`anydbm` + Generic interface to ``dbm``\ -style databases. + + Module :mod:`dbm` + Similar interface to the DBM/NDBM library. + + Module :mod:`gdbm` + Similar interface to the GNU GDBM library. + + Module :mod:`shelve` + Persistence module which stores non-string data. + + Module :mod:`whichdb` + Utility module used to determine the type of an existing database. + + +.. _dumbdbm-objects: + +Dumbdbm Objects +--------------- + +In addition to the methods provided by the :class:`UserDict.DictMixin` class, +:class:`dumbdbm` objects provide the following methods. + + +.. method:: dumbdbm.sync() + + Synchronize the on-disk directory and data files. This method is called by the + :meth:`sync` method of :class:`Shelve` objects. + diff --git a/Doc/library/dummy_thread.rst b/Doc/library/dummy_thread.rst new file mode 100644 index 0000000..0b2cb17 --- /dev/null +++ b/Doc/library/dummy_thread.rst @@ -0,0 +1,23 @@ + +:mod:`dummy_thread` --- Drop-in replacement for the :mod:`thread` module +======================================================================== + +.. module:: dummy_thread + :synopsis: Drop-in replacement for the thread module. + + +This module provides a duplicate interface to the :mod:`thread` module. It is +meant to be imported when the :mod:`thread` module is not provided on a +platform. + +Suggested usage is:: + + try: + import thread as _thread + except ImportError: + import dummy_thread as _thread + +Be careful to not use this module where deadlock might occur from a thread +being created that blocks waiting for another thread to be created. This often +occurs with blocking I/O. + diff --git a/Doc/library/dummy_threading.rst b/Doc/library/dummy_threading.rst new file mode 100644 index 0000000..0ffb687 --- /dev/null +++ b/Doc/library/dummy_threading.rst @@ -0,0 +1,23 @@ + +:mod:`dummy_threading` --- Drop-in replacement for the :mod:`threading` module +============================================================================== + +.. module:: dummy_threading + :synopsis: Drop-in replacement for the threading module. + + +This module provides a duplicate interface to the :mod:`threading` module. It +is meant to be imported when the :mod:`thread` module is not provided on a +platform. + +Suggested usage is:: + + try: + import threading as _threading + except ImportError: + import dummy_threading as _threading + +Be careful to not use this module where deadlock might occur from a thread +being created that blocks waiting for another thread to be created. This often +occurs with blocking I/O. + diff --git a/Doc/library/easydialogs.rst b/Doc/library/easydialogs.rst new file mode 100644 index 0000000..50b312f --- /dev/null +++ b/Doc/library/easydialogs.rst @@ -0,0 +1,207 @@ + +:mod:`EasyDialogs` --- Basic Macintosh dialogs +============================================== + +.. module:: EasyDialogs + :platform: Mac + :synopsis: Basic Macintosh dialogs. + + +The :mod:`EasyDialogs` module contains some simple dialogs for the Macintosh. +All routines take an optional resource ID parameter *id* with which one can +override the :const:`DLOG` resource used for the dialog, provided that the +dialog items correspond (both type and item number) to those in the default +:const:`DLOG` resource. See source code for details. + +The :mod:`EasyDialogs` module defines the following functions: + + +.. function:: Message(str[, id[, ok]]) + + Displays a modal dialog with the message text *str*, which should be at most 255 + characters long. The button text defaults to "OK", but is set to the string + argument *ok* if the latter is supplied. Control is returned when the user + clicks the "OK" button. + + +.. function:: AskString(prompt[, default[, id[, ok[, cancel]]]]) + + Asks the user to input a string value via a modal dialog. *prompt* is the prompt + message, and the optional *default* supplies the initial value for the string + (otherwise ``""`` is used). The text of the "OK" and "Cancel" buttons can be + changed with the *ok* and *cancel* arguments. All strings can be at most 255 + bytes long. :func:`AskString` returns the string entered or :const:`None` in + case the user cancelled. + + +.. function:: AskPassword(prompt[, default[, id[, ok[, cancel]]]]) + + Asks the user to input a string value via a modal dialog. Like + :func:`AskString`, but with the text shown as bullets. The arguments have the + same meaning as for :func:`AskString`. + + +.. function:: AskYesNoCancel(question[, default[, yes[, no[, cancel[, id]]]]]) + + Presents a dialog with prompt *question* and three buttons labelled "Yes", "No", + and "Cancel". Returns ``1`` for "Yes", ``0`` for "No" and ``-1`` for "Cancel". + The value of *default* (or ``0`` if *default* is not supplied) is returned when + the :kbd:`RETURN` key is pressed. The text of the buttons can be changed with + the *yes*, *no*, and *cancel* arguments; to prevent a button from appearing, + supply ``""`` for the corresponding argument. + + +.. function:: ProgressBar([title[, maxval[, label[, id]]]]) + + Displays a modeless progress-bar dialog. This is the constructor for the + :class:`ProgressBar` class described below. *title* is the text string displayed + (default "Working..."), *maxval* is the value at which progress is complete + (default ``0``, indicating that an indeterminate amount of work remains to be + done), and *label* is the text that is displayed above the progress bar itself. + + +.. function:: GetArgv([optionlist[ commandlist[, addoldfile[, addnewfile[, addfolder[, id]]]]]]) + + Displays a dialog which aids the user in constructing a command-line argument + list. Returns the list in ``sys.argv`` format, suitable for passing as an + argument to :func:`getopt.getopt`. *addoldfile*, *addnewfile*, and *addfolder* + are boolean arguments. When nonzero, they enable the user to insert into the + command line paths to an existing file, a (possibly) not-yet-existent file, and + a folder, respectively. (Note: Option arguments must appear in the command line + before file and folder arguments in order to be recognized by + :func:`getopt.getopt`.) Arguments containing spaces can be specified by + enclosing them within single or double quotes. A :exc:`SystemExit` exception is + raised if the user presses the "Cancel" button. + + *optionlist* is a list that determines a popup menu from which the allowed + options are selected. Its items can take one of two forms: *optstr* or + ``(optstr, descr)``. When present, *descr* is a short descriptive string that + is displayed in the dialog while this option is selected in the popup menu. The + correspondence between *optstr*\s and command-line arguments is: + + +----------------------+------------------------------------------+ + | *optstr* format | Command-line format | + +======================+==========================================+ + | ``x`` | :option:`-x` (short option) | + +----------------------+------------------------------------------+ + | ``x:`` or ``x=`` | :option:`-x` (short option with value) | + +----------------------+------------------------------------------+ + | ``xyz`` | :option:`--xyz` (long option) | + +----------------------+------------------------------------------+ + | ``xyz:`` or ``xyz=`` | :option:`--xyz` (long option with value) | + +----------------------+------------------------------------------+ + + *commandlist* is a list of items of the form *cmdstr* or ``(cmdstr, descr)``, + where *descr* is as above. The *cmdstr*s will appear in a popup menu. When + chosen, the text of *cmdstr* will be appended to the command line as is, except + that a trailing ``':'`` or ``'='`` (if present) will be trimmed off. + + .. versionadded:: 2.0 + + +.. function:: AskFileForOpen( [message] [, typeList] [, defaultLocation] [, defaultOptionFlags] [, location] [, clientName] [, windowTitle] [, actionButtonLabel] [, cancelButtonLabel] [, preferenceKey] [, popupExtension] [, eventProc] [, previewProc] [, filterProc] [, wanted] ) + + Post a dialog asking the user for a file to open, and return the file selected + or :const:`None` if the user cancelled. *message* is a text message to display, + *typeList* is a list of 4-char filetypes allowable, *defaultLocation* is the + pathname, :class:`FSSpec` or :class:`FSRef` of the folder to show initially, + *location* is the ``(x, y)`` position on the screen where the dialog is shown, + *actionButtonLabel* is a string to show instead of "Open" in the OK button, + *cancelButtonLabel* is a string to show instead of "Cancel" in the cancel + button, *wanted* is the type of value wanted as a return: :class:`str`, + :class:`unicode`, :class:`FSSpec`, :class:`FSRef` and subtypes thereof are + acceptable. + + .. index:: single: Navigation Services + + For a description of the other arguments please see the Apple Navigation + Services documentation and the :mod:`EasyDialogs` source code. + + +.. function:: AskFileForSave( [message] [, savedFileName] [, defaultLocation] [, defaultOptionFlags] [, location] [, clientName] [, windowTitle] [, actionButtonLabel] [, cancelButtonLabel] [, preferenceKey] [, popupExtension] [, fileType] [, fileCreator] [, eventProc] [, wanted] ) + + Post a dialog asking the user for a file to save to, and return the file + selected or :const:`None` if the user cancelled. *savedFileName* is the default + for the file name to save to (the return value). See :func:`AskFileForOpen` for + a description of the other arguments. + + +.. function:: AskFolder( [message] [, defaultLocation] [, defaultOptionFlags] [, location] [, clientName] [, windowTitle] [, actionButtonLabel] [, cancelButtonLabel] [, preferenceKey] [, popupExtension] [, eventProc] [, filterProc] [, wanted] ) + + Post a dialog asking the user to select a folder, and return the folder selected + or :const:`None` if the user cancelled. See :func:`AskFileForOpen` for a + description of the arguments. + + +.. seealso:: + + `Navigation Services Reference `_ + Programmer's reference documentation for the Navigation Services, a part of the + Carbon framework. + + +.. _progressbar-objects: + +ProgressBar Objects +------------------- + +:class:`ProgressBar` objects provide support for modeless progress-bar dialogs. +Both determinate (thermometer style) and indeterminate (barber-pole style) +progress bars are supported. The bar will be determinate if its maximum value +is greater than zero; otherwise it will be indeterminate. + +.. versionchanged:: 2.2 + Support for indeterminate-style progress bars was added. + +The dialog is displayed immediately after creation. If the dialog's "Cancel" +button is pressed, or if :kbd:`Cmd-.` or :kbd:`ESC` is typed, the dialog window +is hidden and :exc:`KeyboardInterrupt` is raised (but note that this response +does not occur until the progress bar is next updated, typically via a call to +:meth:`inc` or :meth:`set`). Otherwise, the bar remains visible until the +:class:`ProgressBar` object is discarded. + +:class:`ProgressBar` objects possess the following attributes and methods: + + +.. attribute:: ProgressBar.curval + + The current value (of type integer or long integer) of the progress bar. The + normal access methods coerce :attr:`curval` between ``0`` and :attr:`maxval`. + This attribute should not be altered directly. + + +.. attribute:: ProgressBar.maxval + + The maximum value (of type integer or long integer) of the progress bar; the + progress bar (thermometer style) is full when :attr:`curval` equals + :attr:`maxval`. If :attr:`maxval` is ``0``, the bar will be indeterminate + (barber-pole). This attribute should not be altered directly. + + +.. method:: ProgressBar.title([newstr]) + + Sets the text in the title bar of the progress dialog to *newstr*. + + +.. method:: ProgressBar.label([newstr]) + + Sets the text in the progress box of the progress dialog to *newstr*. + + +.. method:: ProgressBar.set(value[, max]) + + Sets the progress bar's :attr:`curval` to *value*, and also :attr:`maxval` to + *max* if the latter is provided. *value* is first coerced between 0 and + :attr:`maxval`. The thermometer bar is updated to reflect the changes, + including a change from indeterminate to determinate or vice versa. + + +.. method:: ProgressBar.inc([n]) + + Increments the progress bar's :attr:`curval` by *n*, or by ``1`` if *n* is not + provided. (Note that *n* may be negative, in which case the effect is a + decrement.) The progress bar is updated to reflect the change. If the bar is + indeterminate, this causes one "spin" of the barber pole. The resulting + :attr:`curval` is coerced between 0 and :attr:`maxval` if incrementing causes it + to fall outside this range. + diff --git a/Doc/library/email-examples.rst b/Doc/library/email-examples.rst new file mode 100644 index 0000000..64a9944 --- /dev/null +++ b/Doc/library/email-examples.rst @@ -0,0 +1,33 @@ +:mod:`email`: Examples +---------------------- + +Here are a few examples of how to use the :mod:`email` package to read, write, +and send simple email messages, as well as more complex MIME messages. + +First, let's see how to create and send a simple text message: + +.. literalinclude:: ../includes/email-simple.py + + +Here's an example of how to send a MIME message containing a bunch of family +pictures that may be residing in a directory: + +.. literalinclude:: ../includes/email-mime.py + + +Here's an example of how to send the entire contents of a directory as an email +message: [1]_ + +.. literalinclude:: ../includes/email-dir.py + + +And finally, here's an example of how to unpack a MIME message like the one +above, into a directory of files: + +.. literalinclude:: ../includes/email-unpack.py + + +.. rubric:: Footnotes + +.. [1] Thanks to Matthew Dixon Cowles for the original inspiration and examples. + diff --git a/Doc/library/email.charset.rst b/Doc/library/email.charset.rst new file mode 100644 index 0000000..d16d281 --- /dev/null +++ b/Doc/library/email.charset.rst @@ -0,0 +1,249 @@ +:mod:`email`: Representing character sets +----------------------------------------- + +.. module:: email.charset + :synopsis: Character Sets + + +This module provides a class :class:`Charset` for representing character sets +and character set conversions in email messages, as well as a character set +registry and several convenience methods for manipulating this registry. +Instances of :class:`Charset` are used in several other modules within the +:mod:`email` package. + +Import this class from the :mod:`email.charset` module. + +.. versionadded:: 2.2.2 + + +.. class:: Charset([input_charset]) + + Map character sets to their email properties. + + This class provides information about the requirements imposed on email for a + specific character set. It also provides convenience routines for converting + between character sets, given the availability of the applicable codecs. Given + a character set, it will do its best to provide information on how to use that + character set in an email message in an RFC-compliant way. + + Certain character sets must be encoded with quoted-printable or base64 when used + in email headers or bodies. Certain character sets must be converted outright, + and are not allowed in email. + + Optional *input_charset* is as described below; it is always coerced to lower + case. After being alias normalized it is also used as a lookup into the + registry of character sets to find out the header encoding, body encoding, and + output conversion codec to be used for the character set. For example, if + *input_charset* is ``iso-8859-1``, then headers and bodies will be encoded using + quoted-printable and no output conversion codec is necessary. If + *input_charset* is ``euc-jp``, then headers will be encoded with base64, bodies + will not be encoded, but output text will be converted from the ``euc-jp`` + character set to the ``iso-2022-jp`` character set. + +:class:`Charset` instances have the following data attributes: + + +.. data:: input_charset + + The initial character set specified. Common aliases are converted to their + *official* email names (e.g. ``latin_1`` is converted to ``iso-8859-1``). + Defaults to 7-bit ``us-ascii``. + + +.. data:: header_encoding + + If the character set must be encoded before it can be used in an email header, + this attribute will be set to ``Charset.QP`` (for quoted-printable), + ``Charset.BASE64`` (for base64 encoding), or ``Charset.SHORTEST`` for the + shortest of QP or BASE64 encoding. Otherwise, it will be ``None``. + + +.. data:: body_encoding + + Same as *header_encoding*, but describes the encoding for the mail message's + body, which indeed may be different than the header encoding. + ``Charset.SHORTEST`` is not allowed for *body_encoding*. + + +.. data:: output_charset + + Some character sets must be converted before they can be used in email headers + or bodies. If the *input_charset* is one of them, this attribute will contain + the name of the character set output will be converted to. Otherwise, it will + be ``None``. + + +.. data:: input_codec + + The name of the Python codec used to convert the *input_charset* to Unicode. If + no conversion codec is necessary, this attribute will be ``None``. + + +.. data:: output_codec + + The name of the Python codec used to convert Unicode to the *output_charset*. + If no conversion codec is necessary, this attribute will have the same value as + the *input_codec*. + +:class:`Charset` instances also have the following methods: + + +.. method:: Charset.get_body_encoding() + + Return the content transfer encoding used for body encoding. + + This is either the string ``quoted-printable`` or ``base64`` depending on the + encoding used, or it is a function, in which case you should call the function + with a single argument, the Message object being encoded. The function should + then set the :mailheader:`Content-Transfer-Encoding` header itself to whatever + is appropriate. + + Returns the string ``quoted-printable`` if *body_encoding* is ``QP``, returns + the string ``base64`` if *body_encoding* is ``BASE64``, and returns the string + ``7bit`` otherwise. + + +.. method:: Charset.convert(s) + + Convert the string *s* from the *input_codec* to the *output_codec*. + + +.. method:: Charset.to_splittable(s) + + Convert a possibly multibyte string to a safely splittable format. *s* is the + string to split. + + Uses the *input_codec* to try and convert the string to Unicode, so it can be + safely split on character boundaries (even for multibyte characters). + + Returns the string as-is if it isn't known how to convert *s* to Unicode with + the *input_charset*. + + Characters that could not be converted to Unicode will be replaced with the + Unicode replacement character ``'U+FFFD'``. + + +.. method:: Charset.from_splittable(ustr[, to_output]) + + Convert a splittable string back into an encoded string. *ustr* is a Unicode + string to "unsplit". + + This method uses the proper codec to try and convert the string from Unicode + back into an encoded format. Return the string as-is if it is not Unicode, or + if it could not be converted from Unicode. + + Characters that could not be converted from Unicode will be replaced with an + appropriate character (usually ``'?'``). + + If *to_output* is ``True`` (the default), uses *output_codec* to convert to an + encoded format. If *to_output* is ``False``, it uses *input_codec*. + + +.. method:: Charset.get_output_charset() + + Return the output character set. + + This is the *output_charset* attribute if that is not ``None``, otherwise it is + *input_charset*. + + +.. method:: Charset.encoded_header_len() + + Return the length of the encoded header string, properly calculating for + quoted-printable or base64 encoding. + + +.. method:: Charset.header_encode(s[, convert]) + + Header-encode the string *s*. + + If *convert* is ``True``, the string will be converted from the input charset to + the output charset automatically. This is not useful for multibyte character + sets, which have line length issues (multibyte characters must be split on a + character, not a byte boundary); use the higher-level :class:`Header` class to + deal with these issues (see :mod:`email.header`). *convert* defaults to + ``False``. + + The type of encoding (base64 or quoted-printable) will be based on the + *header_encoding* attribute. + + +.. method:: Charset.body_encode(s[, convert]) + + Body-encode the string *s*. + + If *convert* is ``True`` (the default), the string will be converted from the + input charset to output charset automatically. Unlike :meth:`header_encode`, + there are no issues with byte boundaries and multibyte charsets in email bodies, + so this is usually pretty safe. + + The type of encoding (base64 or quoted-printable) will be based on the + *body_encoding* attribute. + +The :class:`Charset` class also provides a number of methods to support standard +operations and built-in functions. + + +.. method:: Charset.__str__() + + Returns *input_charset* as a string coerced to lower case. :meth:`__repr__` is + an alias for :meth:`__str__`. + + +.. method:: Charset.__eq__(other) + + This method allows you to compare two :class:`Charset` instances for equality. + + +.. method:: Header.__ne__(other) + + This method allows you to compare two :class:`Charset` instances for inequality. + +The :mod:`email.charset` module also provides the following functions for adding +new entries to the global character set, alias, and codec registries: + + +.. function:: add_charset(charset[, header_enc[, body_enc[, output_charset]]]) + + Add character properties to the global registry. + + *charset* is the input character set, and must be the canonical name of a + character set. + + Optional *header_enc* and *body_enc* is either ``Charset.QP`` for + quoted-printable, ``Charset.BASE64`` for base64 encoding, + ``Charset.SHORTEST`` for the shortest of quoted-printable or base64 encoding, + or ``None`` for no encoding. ``SHORTEST`` is only valid for + *header_enc*. The default is ``None`` for no encoding. + + Optional *output_charset* is the character set that the output should be in. + Conversions will proceed from input charset, to Unicode, to the output charset + when the method :meth:`Charset.convert` is called. The default is to output in + the same character set as the input. + + Both *input_charset* and *output_charset* must have Unicode codec entries in the + module's character set-to-codec mapping; use :func:`add_codec` to add codecs the + module does not know about. See the :mod:`codecs` module's documentation for + more information. + + The global character set registry is kept in the module global dictionary + ``CHARSETS``. + + +.. function:: add_alias(alias, canonical) + + Add a character set alias. *alias* is the alias name, e.g. ``latin-1``. + *canonical* is the character set's canonical name, e.g. ``iso-8859-1``. + + The global charset alias registry is kept in the module global dictionary + ``ALIASES``. + + +.. function:: add_codec(charset, codecname) + + Add a codec that map characters in the given character set to and from Unicode. + + *charset* is the canonical name of a character set. *codecname* is the name of a + Python codec, as appropriate for the second argument to the :func:`unicode` + built-in, or to the :meth:`encode` method of a Unicode string. + diff --git a/Doc/library/email.encoders.rst b/Doc/library/email.encoders.rst new file mode 100644 index 0000000..28669c4 --- /dev/null +++ b/Doc/library/email.encoders.rst @@ -0,0 +1,57 @@ +:mod:`email`: Encoders +---------------------- + +.. module:: email.encoders + :synopsis: Encoders for email message payloads. + + +When creating :class:`Message` objects from scratch, you often need to encode +the payloads for transport through compliant mail servers. This is especially +true for :mimetype:`image/\*` and :mimetype:`text/\*` type messages containing +binary data. + +The :mod:`email` package provides some convenient encodings in its +:mod:`encoders` module. These encoders are actually used by the +:class:`MIMEAudio` and :class:`MIMEImage` class constructors to provide default +encodings. All encoder functions take exactly one argument, the message object +to encode. They usually extract the payload, encode it, and reset the payload +to this newly encoded value. They should also set the +:mailheader:`Content-Transfer-Encoding` header as appropriate. + +Here are the encoding functions provided: + + +.. function:: encode_quopri(msg) + + Encodes the payload into quoted-printable form and sets the + :mailheader:`Content-Transfer-Encoding` header to ``quoted-printable`` [#]_. + This is a good encoding to use when most of your payload is normal printable + data, but contains a few unprintable characters. + + +.. function:: encode_base64(msg) + + Encodes the payload into base64 form and sets the + :mailheader:`Content-Transfer-Encoding` header to ``base64``. This is a good + encoding to use when most of your payload is unprintable data since it is a more + compact form than quoted-printable. The drawback of base64 encoding is that it + renders the text non-human readable. + + +.. function:: encode_7or8bit(msg) + + This doesn't actually modify the message's payload, but it does set the + :mailheader:`Content-Transfer-Encoding` header to either ``7bit`` or ``8bit`` as + appropriate, based on the payload data. + + +.. function:: encode_noop(msg) + + This does nothing; it doesn't even set the + :mailheader:`Content-Transfer-Encoding` header. + +.. rubric:: Footnotes + +.. [#] Note that encoding with :meth:`encode_quopri` also encodes all tabs and space + characters in the data. + diff --git a/Doc/library/email.errors.rst b/Doc/library/email.errors.rst new file mode 100644 index 0000000..916d2a5 --- /dev/null +++ b/Doc/library/email.errors.rst @@ -0,0 +1,91 @@ +:mod:`email`: Exception and Defect classes +------------------------------------------ + +.. module:: email.errors + :synopsis: The exception classes used by the email package. + + +The following exception classes are defined in the :mod:`email.errors` module: + + +.. exception:: MessageError() + + This is the base class for all exceptions that the :mod:`email` package can + raise. It is derived from the standard :exc:`Exception` class and defines no + additional methods. + + +.. exception:: MessageParseError() + + This is the base class for exceptions thrown by the :class:`Parser` class. It + is derived from :exc:`MessageError`. + + +.. exception:: HeaderParseError() + + Raised under some error conditions when parsing the :rfc:`2822` headers of a + message, this class is derived from :exc:`MessageParseError`. It can be raised + from the :meth:`Parser.parse` or :meth:`Parser.parsestr` methods. + + Situations where it can be raised include finding an envelope header after the + first :rfc:`2822` header of the message, finding a continuation line before the + first :rfc:`2822` header is found, or finding a line in the headers which is + neither a header or a continuation line. + + +.. exception:: BoundaryError() + + Raised under some error conditions when parsing the :rfc:`2822` headers of a + message, this class is derived from :exc:`MessageParseError`. It can be raised + from the :meth:`Parser.parse` or :meth:`Parser.parsestr` methods. + + Situations where it can be raised include not being able to find the starting or + terminating boundary in a :mimetype:`multipart/\*` message when strict parsing + is used. + + +.. exception:: MultipartConversionError() + + Raised when a payload is added to a :class:`Message` object using + :meth:`add_payload`, but the payload is already a scalar and the message's + :mailheader:`Content-Type` main type is not either :mimetype:`multipart` or + missing. :exc:`MultipartConversionError` multiply inherits from + :exc:`MessageError` and the built-in :exc:`TypeError`. + + Since :meth:`Message.add_payload` is deprecated, this exception is rarely raised + in practice. However the exception may also be raised if the :meth:`attach` + method is called on an instance of a class derived from + :class:`MIMENonMultipart` (e.g. :class:`MIMEImage`). + +Here's the list of the defects that the :class:`FeedParser` can find while +parsing messages. Note that the defects are added to the message where the +problem was found, so for example, if a message nested inside a +:mimetype:`multipart/alternative` had a malformed header, that nested message +object would have a defect, but the containing messages would not. + +All defect classes are subclassed from :class:`email.errors.MessageDefect`, but +this class is *not* an exception! + +.. versionadded:: 2.4 + All the defect classes were added. + +* :class:`NoBoundaryInMultipartDefect` -- A message claimed to be a multipart, + but had no :mimetype:`boundary` parameter. + +* :class:`StartBoundaryNotFoundDefect` -- The start boundary claimed in the + :mailheader:`Content-Type` header was never found. + +* :class:`FirstHeaderLineIsContinuationDefect` -- The message had a continuation + line as its first header line. + +* :class:`MisplacedEnvelopeHeaderDefect` - A "Unix From" header was found in the + middle of a header block. + +* :class:`MalformedHeaderDefect` -- A header was found that was missing a colon, + or was otherwise malformed. + +* :class:`MultipartInvariantViolationDefect` -- A message claimed to be a + :mimetype:`multipart`, but no subparts were found. Note that when a message has + this defect, its :meth:`is_multipart` method may return false even though its + content type claims to be :mimetype:`multipart`. + diff --git a/Doc/library/email.generator.rst b/Doc/library/email.generator.rst new file mode 100644 index 0000000..bb1f57d --- /dev/null +++ b/Doc/library/email.generator.rst @@ -0,0 +1,123 @@ +:mod:`email`: Generating MIME documents +--------------------------------------- + +.. module:: email.generator + :synopsis: Generate flat text email messages from a message structure. + + +One of the most common tasks is to generate the flat text of the email message +represented by a message object structure. You will need to do this if you want +to send your message via the :mod:`smtplib` module or the :mod:`nntplib` module, +or print the message on the console. Taking a message object structure and +producing a flat text document is the job of the :class:`Generator` class. + +Again, as with the :mod:`email.parser` module, you aren't limited to the +functionality of the bundled generator; you could write one from scratch +yourself. However the bundled generator knows how to generate most email in a +standards-compliant way, should handle MIME and non-MIME email messages just +fine, and is designed so that the transformation from flat text, to a message +structure via the :class:`Parser` class, and back to flat text, is idempotent +(the input is identical to the output). + +Here are the public methods of the :class:`Generator` class, imported from the +:mod:`email.generator` module: + + +.. class:: Generator(outfp[, mangle_from_[, maxheaderlen]]) + + The constructor for the :class:`Generator` class takes a file-like object called + *outfp* for an argument. *outfp* must support the :meth:`write` method and be + usable as the output file in a Python extended print statement. + + Optional *mangle_from_* is a flag that, when ``True``, puts a ``>`` character in + front of any line in the body that starts exactly as ``From``, i.e. ``From`` + followed by a space at the beginning of the line. This is the only guaranteed + portable way to avoid having such lines be mistaken for a Unix mailbox format + envelope header separator (see `WHY THE CONTENT-LENGTH FORMAT IS BAD + `_ for details). *mangle_from_* + defaults to ``True``, but you might want to set this to ``False`` if you are not + writing Unix mailbox format files. + + Optional *maxheaderlen* specifies the longest length for a non-continued header. + When a header line is longer than *maxheaderlen* (in characters, with tabs + expanded to 8 spaces), the header will be split as defined in the + :mod:`email.header.Header` class. Set to zero to disable header wrapping. The + default is 78, as recommended (but not required) by :rfc:`2822`. + +The other public :class:`Generator` methods are: + + +.. method:: Generator.flatten(msg[, unixfrom]) + + Print the textual representation of the message object structure rooted at *msg* + to the output file specified when the :class:`Generator` instance was created. + Subparts are visited depth-first and the resulting text will be properly MIME + encoded. + + Optional *unixfrom* is a flag that forces the printing of the envelope header + delimiter before the first :rfc:`2822` header of the root message object. If + the root object has no envelope header, a standard one is crafted. By default, + this is set to ``False`` to inhibit the printing of the envelope delimiter. + + Note that for subparts, no envelope header is ever printed. + + .. versionadded:: 2.2.2 + + +.. method:: Generator.clone(fp) + + Return an independent clone of this :class:`Generator` instance with the exact + same options. + + .. versionadded:: 2.2.2 + + +.. method:: Generator.write(s) + + Write the string *s* to the underlying file object, i.e. *outfp* passed to + :class:`Generator`'s constructor. This provides just enough file-like API for + :class:`Generator` instances to be used in extended print statements. + +As a convenience, see the methods :meth:`Message.as_string` and +``str(aMessage)``, a.k.a. :meth:`Message.__str__`, which simplify the generation +of a formatted string representation of a message object. For more detail, see +:mod:`email.message`. + +The :mod:`email.generator` module also provides a derived class, called +:class:`DecodedGenerator` which is like the :class:`Generator` base class, +except that non-\ :mimetype:`text` parts are substituted with a format string +representing the part. + + +.. class:: DecodedGenerator(outfp[, mangle_from_[, maxheaderlen[, fmt]]]) + + This class, derived from :class:`Generator` walks through all the subparts of a + message. If the subpart is of main type :mimetype:`text`, then it prints the + decoded payload of the subpart. Optional *_mangle_from_* and *maxheaderlen* are + as with the :class:`Generator` base class. + + If the subpart is not of main type :mimetype:`text`, optional *fmt* is a format + string that is used instead of the message payload. *fmt* is expanded with the + following keywords, ``%(keyword)s`` format: + + * ``type`` -- Full MIME type of the non-\ :mimetype:`text` part + + * ``maintype`` -- Main MIME type of the non-\ :mimetype:`text` part + + * ``subtype`` -- Sub-MIME type of the non-\ :mimetype:`text` part + + * ``filename`` -- Filename of the non-\ :mimetype:`text` part + + * ``description`` -- Description associated with the non-\ :mimetype:`text` part + + * ``encoding`` -- Content transfer encoding of the non-\ :mimetype:`text` part + + The default value for *fmt* is ``None``, meaning :: + + [Non-text (%(type)s) part of message omitted, filename %(filename)s] + + .. versionadded:: 2.2.2 + +.. versionchanged:: 2.5 + The previously deprecated method :meth:`__call__` was removed. + diff --git a/Doc/library/email.header.rst b/Doc/library/email.header.rst new file mode 100644 index 0000000..0ecd35f --- /dev/null +++ b/Doc/library/email.header.rst @@ -0,0 +1,171 @@ +:mod:`email`: Internationalized headers +--------------------------------------- + +.. module:: email.header + :synopsis: Representing non-ASCII headers + + +:rfc:`2822` is the base standard that describes the format of email messages. +It derives from the older :rfc:`822` standard which came into widespread use at +a time when most email was composed of ASCII characters only. :rfc:`2822` is a +specification written assuming email contains only 7-bit ASCII characters. + +Of course, as email has been deployed worldwide, it has become +internationalized, such that language specific character sets can now be used in +email messages. The base standard still requires email messages to be +transferred using only 7-bit ASCII characters, so a slew of RFCs have been +written describing how to encode email containing non-ASCII characters into +:rfc:`2822`\ -compliant format. These RFCs include :rfc:`2045`, :rfc:`2046`, +:rfc:`2047`, and :rfc:`2231`. The :mod:`email` package supports these standards +in its :mod:`email.header` and :mod:`email.charset` modules. + +If you want to include non-ASCII characters in your email headers, say in the +:mailheader:`Subject` or :mailheader:`To` fields, you should use the +:class:`Header` class and assign the field in the :class:`Message` object to an +instance of :class:`Header` instead of using a string for the header value. +Import the :class:`Header` class from the :mod:`email.header` module. For +example:: + + >>> from email.message import Message + >>> from email.header import Header + >>> msg = Message() + >>> h = Header('p\xf6stal', 'iso-8859-1') + >>> msg['Subject'] = h + >>> print msg.as_string() + Subject: =?iso-8859-1?q?p=F6stal?= + + + +Notice here how we wanted the :mailheader:`Subject` field to contain a non-ASCII +character? We did this by creating a :class:`Header` instance and passing in +the character set that the byte string was encoded in. When the subsequent +:class:`Message` instance was flattened, the :mailheader:`Subject` field was +properly :rfc:`2047` encoded. MIME-aware mail readers would show this header +using the embedded ISO-8859-1 character. + +.. versionadded:: 2.2.2 + +Here is the :class:`Header` class description: + + +.. class:: Header([s[, charset[, maxlinelen[, header_name[, continuation_ws[, errors]]]]]]) + + Create a MIME-compliant header that can contain strings in different character + sets. + + Optional *s* is the initial header value. If ``None`` (the default), the + initial header value is not set. You can later append to the header with + :meth:`append` method calls. *s* may be a byte string or a Unicode string, but + see the :meth:`append` documentation for semantics. + + Optional *charset* serves two purposes: it has the same meaning as the *charset* + argument to the :meth:`append` method. It also sets the default character set + for all subsequent :meth:`append` calls that omit the *charset* argument. If + *charset* is not provided in the constructor (the default), the ``us-ascii`` + character set is used both as *s*'s initial charset and as the default for + subsequent :meth:`append` calls. + + The maximum line length can be specified explicit via *maxlinelen*. For + splitting the first line to a shorter value (to account for the field header + which isn't included in *s*, e.g. :mailheader:`Subject`) pass in the name of the + field in *header_name*. The default *maxlinelen* is 76, and the default value + for *header_name* is ``None``, meaning it is not taken into account for the + first line of a long, split header. + + Optional *continuation_ws* must be :rfc:`2822`\ -compliant folding whitespace, + and is usually either a space or a hard tab character. This character will be + prepended to continuation lines. + +Optional *errors* is passed straight through to the :meth:`append` method. + + +.. method:: Header.append(s[, charset[, errors]]) + + Append the string *s* to the MIME header. + + Optional *charset*, if given, should be a :class:`Charset` instance (see + :mod:`email.charset`) or the name of a character set, which will be converted to + a :class:`Charset` instance. A value of ``None`` (the default) means that the + *charset* given in the constructor is used. + + *s* may be a byte string or a Unicode string. If it is a byte string (i.e. + ``isinstance(s, str)`` is true), then *charset* is the encoding of that byte + string, and a :exc:`UnicodeError` will be raised if the string cannot be decoded + with that character set. + + If *s* is a Unicode string, then *charset* is a hint specifying the character + set of the characters in the string. In this case, when producing an + :rfc:`2822`\ -compliant header using :rfc:`2047` rules, the Unicode string will + be encoded using the following charsets in order: ``us-ascii``, the *charset* + hint, ``utf-8``. The first character set to not provoke a :exc:`UnicodeError` + is used. + + Optional *errors* is passed through to any :func:`unicode` or + :func:`ustr.encode` call, and defaults to "strict". + + +.. method:: Header.encode([splitchars]) + + Encode a message header into an RFC-compliant format, possibly wrapping long + lines and encapsulating non-ASCII parts in base64 or quoted-printable encodings. + Optional *splitchars* is a string containing characters to split long ASCII + lines on, in rough support of :rfc:`2822`'s *highest level syntactic breaks*. + This doesn't affect :rfc:`2047` encoded lines. + +The :class:`Header` class also provides a number of methods to support standard +operators and built-in functions. + + +.. method:: Header.__str__() + + A synonym for :meth:`Header.encode`. Useful for ``str(aHeader)``. + + +.. method:: Header.__unicode__() + + A helper for the built-in :func:`unicode` function. Returns the header as a + Unicode string. + + +.. method:: Header.__eq__(other) + + This method allows you to compare two :class:`Header` instances for equality. + + +.. method:: Header.__ne__(other) + + This method allows you to compare two :class:`Header` instances for inequality. + +The :mod:`email.header` module also provides the following convenient functions. + + +.. function:: decode_header(header) + + Decode a message header value without converting the character set. The header + value is in *header*. + + This function returns a list of ``(decoded_string, charset)`` pairs containing + each of the decoded parts of the header. *charset* is ``None`` for non-encoded + parts of the header, otherwise a lower case string containing the name of the + character set specified in the encoded string. + + Here's an example:: + + >>> from email.header import decode_header + >>> decode_header('=?iso-8859-1?q?p=F6stal?=') + [('p\xf6stal', 'iso-8859-1')] + + +.. function:: make_header(decoded_seq[, maxlinelen[, header_name[, continuation_ws]]]) + + Create a :class:`Header` instance from a sequence of pairs as returned by + :func:`decode_header`. + + :func:`decode_header` takes a header value string and returns a sequence of + pairs of the format ``(decoded_string, charset)`` where *charset* is the name of + the character set. + + This function takes one of those sequence of pairs and returns a :class:`Header` + instance. Optional *maxlinelen*, *header_name*, and *continuation_ws* are as in + the :class:`Header` constructor. + diff --git a/Doc/library/email.iterators.rst b/Doc/library/email.iterators.rst new file mode 100644 index 0000000..aa70141 --- /dev/null +++ b/Doc/library/email.iterators.rst @@ -0,0 +1,65 @@ +:mod:`email`: Iterators +----------------------- + +.. module:: email.iterators + :synopsis: Iterate over a message object tree. + + +Iterating over a message object tree is fairly easy with the +:meth:`Message.walk` method. The :mod:`email.iterators` module provides some +useful higher level iterations over message object trees. + + +.. function:: body_line_iterator(msg[, decode]) + + This iterates over all the payloads in all the subparts of *msg*, returning the + string payloads line-by-line. It skips over all the subpart headers, and it + skips over any subpart with a payload that isn't a Python string. This is + somewhat equivalent to reading the flat text representation of the message from + a file using :meth:`readline`, skipping over all the intervening headers. + + Optional *decode* is passed through to :meth:`Message.get_payload`. + + +.. function:: typed_subpart_iterator(msg[, maintype[, subtype]]) + + This iterates over all the subparts of *msg*, returning only those subparts that + match the MIME type specified by *maintype* and *subtype*. + + Note that *subtype* is optional; if omitted, then subpart MIME type matching is + done only with the main type. *maintype* is optional too; it defaults to + :mimetype:`text`. + + Thus, by default :func:`typed_subpart_iterator` returns each subpart that has a + MIME type of :mimetype:`text/\*`. + +The following function has been added as a useful debugging tool. It should +*not* be considered part of the supported public interface for the package. + + +.. function:: _structure(msg[, fp[, level]]) + + Prints an indented representation of the content types of the message object + structure. For example:: + + >>> msg = email.message_from_file(somefile) + >>> _structure(msg) + multipart/mixed + text/plain + text/plain + multipart/digest + message/rfc822 + text/plain + message/rfc822 + text/plain + message/rfc822 + text/plain + message/rfc822 + text/plain + message/rfc822 + text/plain + text/plain + + Optional *fp* is a file-like object to print the output to. It must be suitable + for Python's extended print statement. *level* is used internally. + diff --git a/Doc/library/email.message.rst b/Doc/library/email.message.rst new file mode 100644 index 0000000..e1fb20e --- /dev/null +++ b/Doc/library/email.message.rst @@ -0,0 +1,548 @@ +:mod:`email`: Representing an email message +------------------------------------------- + +.. module:: email.message + :synopsis: The base class representing email messages. + + +The central class in the :mod:`email` package is the :class:`Message` class, +imported from the :mod:`email.message` module. It is the base class for the +:mod:`email` object model. :class:`Message` provides the core functionality for +setting and querying header fields, and for accessing message bodies. + +Conceptually, a :class:`Message` object consists of *headers* and *payloads*. +Headers are :rfc:`2822` style field names and values where the field name and +value are separated by a colon. The colon is not part of either the field name +or the field value. + +Headers are stored and returned in case-preserving form but are matched +case-insensitively. There may also be a single envelope header, also known as +the *Unix-From* header or the ``From_`` header. The payload is either a string +in the case of simple message objects or a list of :class:`Message` objects for +MIME container documents (e.g. :mimetype:`multipart/\*` and +:mimetype:`message/rfc822`). + +:class:`Message` objects provide a mapping style interface for accessing the +message headers, and an explicit interface for accessing both the headers and +the payload. It provides convenience methods for generating a flat text +representation of the message object tree, for accessing commonly used header +parameters, and for recursively walking over the object tree. + +Here are the methods of the :class:`Message` class: + + +.. class:: Message() + + The constructor takes no arguments. + + +.. method:: Message.as_string([unixfrom]) + + Return the entire message flatten as a string. When optional *unixfrom* is + ``True``, the envelope header is included in the returned string. *unixfrom* + defaults to ``False``. + + Note that this method is provided as a convenience and may not always format the + message the way you want. For example, by default it mangles lines that begin + with ``From``. For more flexibility, instantiate a :class:`Generator` instance + and use its :meth:`flatten` method directly. For example:: + + from cStringIO import StringIO + from email.generator import Generator + fp = StringIO() + g = Generator(fp, mangle_from_=False, maxheaderlen=60) + g.flatten(msg) + text = fp.getvalue() + + +.. method:: Message.__str__() + + Equivalent to ``as_string(unixfrom=True)``. + + +.. method:: Message.is_multipart() + + Return ``True`` if the message's payload is a list of sub-\ :class:`Message` + objects, otherwise return ``False``. When :meth:`is_multipart` returns False, + the payload should be a string object. + + +.. method:: Message.set_unixfrom(unixfrom) + + Set the message's envelope header to *unixfrom*, which should be a string. + + +.. method:: Message.get_unixfrom() + + Return the message's envelope header. Defaults to ``None`` if the envelope + header was never set. + + +.. method:: Message.attach(payload) + + Add the given *payload* to the current payload, which must be ``None`` or a list + of :class:`Message` objects before the call. After the call, the payload will + always be a list of :class:`Message` objects. If you want to set the payload to + a scalar object (e.g. a string), use :meth:`set_payload` instead. + + +.. method:: Message.get_payload([i[, decode]]) + + Return a reference the current payload, which will be a list of :class:`Message` + objects when :meth:`is_multipart` is ``True``, or a string when + :meth:`is_multipart` is ``False``. If the payload is a list and you mutate the + list object, you modify the message's payload in place. + + With optional argument *i*, :meth:`get_payload` will return the *i*-th element + of the payload, counting from zero, if :meth:`is_multipart` is ``True``. An + :exc:`IndexError` will be raised if *i* is less than 0 or greater than or equal + to the number of items in the payload. If the payload is a string (i.e. + :meth:`is_multipart` is ``False``) and *i* is given, a :exc:`TypeError` is + raised. + + Optional *decode* is a flag indicating whether the payload should be decoded or + not, according to the :mailheader:`Content-Transfer-Encoding` header. When + ``True`` and the message is not a multipart, the payload will be decoded if this + header's value is ``quoted-printable`` or ``base64``. If some other encoding is + used, or :mailheader:`Content-Transfer-Encoding` header is missing, or if the + payload has bogus base64 data, the payload is returned as-is (undecoded). If + the message is a multipart and the *decode* flag is ``True``, then ``None`` is + returned. The default for *decode* is ``False``. + + +.. method:: Message.set_payload(payload[, charset]) + + Set the entire message object's payload to *payload*. It is the client's + responsibility to ensure the payload invariants. Optional *charset* sets the + message's default character set; see :meth:`set_charset` for details. + + .. versionchanged:: 2.2.2 + *charset* argument added. + + +.. method:: Message.set_charset(charset) + + Set the character set of the payload to *charset*, which can either be a + :class:`Charset` instance (see :mod:`email.charset`), a string naming a + character set, or ``None``. If it is a string, it will be converted to a + :class:`Charset` instance. If *charset* is ``None``, the ``charset`` parameter + will be removed from the :mailheader:`Content-Type` header. Anything else will + generate a :exc:`TypeError`. + + The message will be assumed to be of type :mimetype:`text/\*` encoded with + *charset.input_charset*. It will be converted to *charset.output_charset* and + encoded properly, if needed, when generating the plain text representation of + the message. MIME headers (:mailheader:`MIME-Version`, + :mailheader:`Content-Type`, :mailheader:`Content-Transfer-Encoding`) will be + added as needed. + + .. versionadded:: 2.2.2 + + +.. method:: Message.get_charset() + + Return the :class:`Charset` instance associated with the message's payload. + + .. versionadded:: 2.2.2 + +The following methods implement a mapping-like interface for accessing the +message's :rfc:`2822` headers. Note that there are some semantic differences +between these methods and a normal mapping (i.e. dictionary) interface. For +example, in a dictionary there are no duplicate keys, but here there may be +duplicate message headers. Also, in dictionaries there is no guaranteed order +to the keys returned by :meth:`keys`, but in a :class:`Message` object, headers +are always returned in the order they appeared in the original message, or were +added to the message later. Any header deleted and then re-added are always +appended to the end of the header list. + +These semantic differences are intentional and are biased toward maximal +convenience. + +Note that in all cases, any envelope header present in the message is not +included in the mapping interface. + + +.. method:: Message.__len__() + + Return the total number of headers, including duplicates. + + +.. method:: Message.__contains__(name) + + Return true if the message object has a field named *name*. Matching is done + case-insensitively and *name* should not include the trailing colon. Used for + the ``in`` operator, e.g.:: + + if 'message-id' in myMessage: + print 'Message-ID:', myMessage['message-id'] + + +.. method:: Message.__getitem__(name) + + Return the value of the named header field. *name* should not include the colon + field separator. If the header is missing, ``None`` is returned; a + :exc:`KeyError` is never raised. + + Note that if the named field appears more than once in the message's headers, + exactly which of those field values will be returned is undefined. Use the + :meth:`get_all` method to get the values of all the extant named headers. + + +.. method:: Message.__setitem__(name, val) + + Add a header to the message with field name *name* and value *val*. The field + is appended to the end of the message's existing fields. + + Note that this does *not* overwrite or delete any existing header with the same + name. If you want to ensure that the new header is the only one present in the + message with field name *name*, delete the field first, e.g.:: + + del msg['subject'] + msg['subject'] = 'Python roolz!' + + +.. method:: Message.__delitem__(name) + + Delete all occurrences of the field with name *name* from the message's headers. + No exception is raised if the named field isn't present in the headers. + + +.. method:: Message.has_key(name) + + Return true if the message contains a header field named *name*, otherwise + return false. + + +.. method:: Message.keys() + + Return a list of all the message's header field names. + + +.. method:: Message.values() + + Return a list of all the message's field values. + + +.. method:: Message.items() + + Return a list of 2-tuples containing all the message's field headers and values. + + +.. method:: Message.get(name[, failobj]) + + Return the value of the named header field. This is identical to + :meth:`__getitem__` except that optional *failobj* is returned if the named + header is missing (defaults to ``None``). + +Here are some additional useful methods: + + +.. method:: Message.get_all(name[, failobj]) + + Return a list of all the values for the field named *name*. If there are no such + named headers in the message, *failobj* is returned (defaults to ``None``). + + +.. method:: Message.add_header(_name, _value, **_params) + + Extended header setting. This method is similar to :meth:`__setitem__` except + that additional header parameters can be provided as keyword arguments. *_name* + is the header field to add and *_value* is the *primary* value for the header. + + For each item in the keyword argument dictionary *_params*, the key is taken as + the parameter name, with underscores converted to dashes (since dashes are + illegal in Python identifiers). Normally, the parameter will be added as + ``key="value"`` unless the value is ``None``, in which case only the key will be + added. + + Here's an example:: + + msg.add_header('Content-Disposition', 'attachment', filename='bud.gif') + + This will add a header that looks like :: + + Content-Disposition: attachment; filename="bud.gif" + + +.. method:: Message.replace_header(_name, _value) + + Replace a header. Replace the first header found in the message that matches + *_name*, retaining header order and field name case. If no matching header was + found, a :exc:`KeyError` is raised. + + .. versionadded:: 2.2.2 + + +.. method:: Message.get_content_type() + + Return the message's content type. The returned string is coerced to lower case + of the form :mimetype:`maintype/subtype`. If there was no + :mailheader:`Content-Type` header in the message the default type as given by + :meth:`get_default_type` will be returned. Since according to :rfc:`2045`, + messages always have a default type, :meth:`get_content_type` will always return + a value. + + :rfc:`2045` defines a message's default type to be :mimetype:`text/plain` unless + it appears inside a :mimetype:`multipart/digest` container, in which case it + would be :mimetype:`message/rfc822`. If the :mailheader:`Content-Type` header + has an invalid type specification, :rfc:`2045` mandates that the default type be + :mimetype:`text/plain`. + + .. versionadded:: 2.2.2 + + +.. method:: Message.get_content_maintype() + + Return the message's main content type. This is the :mimetype:`maintype` part + of the string returned by :meth:`get_content_type`. + + .. versionadded:: 2.2.2 + + +.. method:: Message.get_content_subtype() + + Return the message's sub-content type. This is the :mimetype:`subtype` part of + the string returned by :meth:`get_content_type`. + + .. versionadded:: 2.2.2 + + +.. method:: Message.get_default_type() + + Return the default content type. Most messages have a default content type of + :mimetype:`text/plain`, except for messages that are subparts of + :mimetype:`multipart/digest` containers. Such subparts have a default content + type of :mimetype:`message/rfc822`. + + .. versionadded:: 2.2.2 + + +.. method:: Message.set_default_type(ctype) + + Set the default content type. *ctype* should either be :mimetype:`text/plain` + or :mimetype:`message/rfc822`, although this is not enforced. The default + content type is not stored in the :mailheader:`Content-Type` header. + + .. versionadded:: 2.2.2 + + +.. method:: Message.get_params([failobj[, header[, unquote]]]) + + Return the message's :mailheader:`Content-Type` parameters, as a list. The + elements of the returned list are 2-tuples of key/value pairs, as split on the + ``'='`` sign. The left hand side of the ``'='`` is the key, while the right + hand side is the value. If there is no ``'='`` sign in the parameter the value + is the empty string, otherwise the value is as described in :meth:`get_param` + and is unquoted if optional *unquote* is ``True`` (the default). + + Optional *failobj* is the object to return if there is no + :mailheader:`Content-Type` header. Optional *header* is the header to search + instead of :mailheader:`Content-Type`. + + .. versionchanged:: 2.2.2 + *unquote* argument added. + + +.. method:: Message.get_param(param[, failobj[, header[, unquote]]]) + + Return the value of the :mailheader:`Content-Type` header's parameter *param* as + a string. If the message has no :mailheader:`Content-Type` header or if there + is no such parameter, then *failobj* is returned (defaults to ``None``). + + Optional *header* if given, specifies the message header to use instead of + :mailheader:`Content-Type`. + + Parameter keys are always compared case insensitively. The return value can + either be a string, or a 3-tuple if the parameter was :rfc:`2231` encoded. When + it's a 3-tuple, the elements of the value are of the form ``(CHARSET, LANGUAGE, + VALUE)``. Note that both ``CHARSET`` and ``LANGUAGE`` can be ``None``, in which + case you should consider ``VALUE`` to be encoded in the ``us-ascii`` charset. + You can usually ignore ``LANGUAGE``. + + If your application doesn't care whether the parameter was encoded as in + :rfc:`2231`, you can collapse the parameter value by calling + :func:`email.Utils.collapse_rfc2231_value`, passing in the return value from + :meth:`get_param`. This will return a suitably decoded Unicode string whn the + value is a tuple, or the original string unquoted if it isn't. For example:: + + rawparam = msg.get_param('foo') + param = email.Utils.collapse_rfc2231_value(rawparam) + + In any case, the parameter value (either the returned string, or the ``VALUE`` + item in the 3-tuple) is always unquoted, unless *unquote* is set to ``False``. + + .. versionchanged:: 2.2.2 + *unquote* argument added, and 3-tuple return value possible. + + +.. method:: Message.set_param(param, value[, header[, requote[, charset[, language]]]]) + + Set a parameter in the :mailheader:`Content-Type` header. If the parameter + already exists in the header, its value will be replaced with *value*. If the + :mailheader:`Content-Type` header as not yet been defined for this message, it + will be set to :mimetype:`text/plain` and the new parameter value will be + appended as per :rfc:`2045`. + + Optional *header* specifies an alternative header to :mailheader:`Content-Type`, + and all parameters will be quoted as necessary unless optional *requote* is + ``False`` (the default is ``True``). + + If optional *charset* is specified, the parameter will be encoded according to + :rfc:`2231`. Optional *language* specifies the RFC 2231 language, defaulting to + the empty string. Both *charset* and *language* should be strings. + + .. versionadded:: 2.2.2 + + +.. method:: Message.del_param(param[, header[, requote]]) + + Remove the given parameter completely from the :mailheader:`Content-Type` + header. The header will be re-written in place without the parameter or its + value. All values will be quoted as necessary unless *requote* is ``False`` + (the default is ``True``). Optional *header* specifies an alternative to + :mailheader:`Content-Type`. + + .. versionadded:: 2.2.2 + + +.. method:: Message.set_type(type[, header][, requote]) + + Set the main type and subtype for the :mailheader:`Content-Type` header. *type* + must be a string in the form :mimetype:`maintype/subtype`, otherwise a + :exc:`ValueError` is raised. + + This method replaces the :mailheader:`Content-Type` header, keeping all the + parameters in place. If *requote* is ``False``, this leaves the existing + header's quoting as is, otherwise the parameters will be quoted (the default). + + An alternative header can be specified in the *header* argument. When the + :mailheader:`Content-Type` header is set a :mailheader:`MIME-Version` header is + also added. + + .. versionadded:: 2.2.2 + + +.. method:: Message.get_filename([failobj]) + + Return the value of the ``filename`` parameter of the + :mailheader:`Content-Disposition` header of the message. If the header does not + have a ``filename`` parameter, this method falls back to looking for the + ``name`` parameter. If neither is found, or the header is missing, then + *failobj* is returned. The returned string will always be unquoted as per + :meth:`Utils.unquote`. + + +.. method:: Message.get_boundary([failobj]) + + Return the value of the ``boundary`` parameter of the :mailheader:`Content-Type` + header of the message, or *failobj* if either the header is missing, or has no + ``boundary`` parameter. The returned string will always be unquoted as per + :meth:`Utils.unquote`. + + +.. method:: Message.set_boundary(boundary) + + Set the ``boundary`` parameter of the :mailheader:`Content-Type` header to + *boundary*. :meth:`set_boundary` will always quote *boundary* if necessary. A + :exc:`HeaderParseError` is raised if the message object has no + :mailheader:`Content-Type` header. + + Note that using this method is subtly different than deleting the old + :mailheader:`Content-Type` header and adding a new one with the new boundary via + :meth:`add_header`, because :meth:`set_boundary` preserves the order of the + :mailheader:`Content-Type` header in the list of headers. However, it does *not* + preserve any continuation lines which may have been present in the original + :mailheader:`Content-Type` header. + + +.. method:: Message.get_content_charset([failobj]) + + Return the ``charset`` parameter of the :mailheader:`Content-Type` header, + coerced to lower case. If there is no :mailheader:`Content-Type` header, or if + that header has no ``charset`` parameter, *failobj* is returned. + + Note that this method differs from :meth:`get_charset` which returns the + :class:`Charset` instance for the default encoding of the message body. + + .. versionadded:: 2.2.2 + + +.. method:: Message.get_charsets([failobj]) + + Return a list containing the character set names in the message. If the message + is a :mimetype:`multipart`, then the list will contain one element for each + subpart in the payload, otherwise, it will be a list of length 1. + + Each item in the list will be a string which is the value of the ``charset`` + parameter in the :mailheader:`Content-Type` header for the represented subpart. + However, if the subpart has no :mailheader:`Content-Type` header, no ``charset`` + parameter, or is not of the :mimetype:`text` main MIME type, then that item in + the returned list will be *failobj*. + + +.. method:: Message.walk() + + The :meth:`walk` method is an all-purpose generator which can be used to iterate + over all the parts and subparts of a message object tree, in depth-first + traversal order. You will typically use :meth:`walk` as the iterator in a + ``for`` loop; each iteration returns the next subpart. + + Here's an example that prints the MIME type of every part of a multipart message + structure:: + + >>> for part in msg.walk(): + ... print part.get_content_type() + multipart/report + text/plain + message/delivery-status + text/plain + text/plain + message/rfc822 + +.. versionchanged:: 2.5 + The previously deprecated methods :meth:`get_type`, :meth:`get_main_type`, and + :meth:`get_subtype` were removed. + +:class:`Message` objects can also optionally contain two instance attributes, +which can be used when generating the plain text of a MIME message. + + +.. data:: preamble + + The format of a MIME document allows for some text between the blank line + following the headers, and the first multipart boundary string. Normally, this + text is never visible in a MIME-aware mail reader because it falls outside the + standard MIME armor. However, when viewing the raw text of the message, or when + viewing the message in a non-MIME aware reader, this text can become visible. + + The *preamble* attribute contains this leading extra-armor text for MIME + documents. When the :class:`Parser` discovers some text after the headers but + before the first boundary string, it assigns this text to the message's + *preamble* attribute. When the :class:`Generator` is writing out the plain text + representation of a MIME message, and it finds the message has a *preamble* + attribute, it will write this text in the area between the headers and the first + boundary. See :mod:`email.parser` and :mod:`email.generator` for details. + + Note that if the message object has no preamble, the *preamble* attribute will + be ``None``. + + +.. data:: epilogue + + The *epilogue* attribute acts the same way as the *preamble* attribute, except + that it contains text that appears between the last boundary and the end of the + message. + + .. versionchanged:: 2.5 + You do not need to set the epilogue to the empty string in order for the + :class:`Generator` to print a newline at the end of the file. + + +.. data:: defects + + The *defects* attribute contains a list of all the problems found when parsing + this message. See :mod:`email.errors` for a detailed description of the + possible parsing defects. + + .. versionadded:: 2.4 + diff --git a/Doc/library/email.mime.rst b/Doc/library/email.mime.rst new file mode 100644 index 0000000..6f1b0ae --- /dev/null +++ b/Doc/library/email.mime.rst @@ -0,0 +1,175 @@ +:mod:`email`: Creating email and MIME objects from scratch +---------------------------------------------------------- + +.. module:: email.mime + :synopsis: Build MIME messages. + + +Ordinarily, you get a message object structure by passing a file or some text to +a parser, which parses the text and returns the root message object. However +you can also build a complete message structure from scratch, or even individual +:class:`Message` objects by hand. In fact, you can also take an existing +structure and add new :class:`Message` objects, move them around, etc. This +makes a very convenient interface for slicing-and-dicing MIME messages. + +You can create a new object structure by creating :class:`Message` instances, +adding attachments and all the appropriate headers manually. For MIME messages +though, the :mod:`email` package provides some convenient subclasses to make +things easier. + +Here are the classes: + + +.. class:: MIMEBase(_maintype, _subtype, **_params) + + Module: :mod:`email.mime.base` + + This is the base class for all the MIME-specific subclasses of :class:`Message`. + Ordinarily you won't create instances specifically of :class:`MIMEBase`, + although you could. :class:`MIMEBase` is provided primarily as a convenient + base class for more specific MIME-aware subclasses. + + *_maintype* is the :mailheader:`Content-Type` major type (e.g. :mimetype:`text` + or :mimetype:`image`), and *_subtype* is the :mailheader:`Content-Type` minor + type (e.g. :mimetype:`plain` or :mimetype:`gif`). *_params* is a parameter + key/value dictionary and is passed directly to :meth:`Message.add_header`. + + The :class:`MIMEBase` class always adds a :mailheader:`Content-Type` header + (based on *_maintype*, *_subtype*, and *_params*), and a + :mailheader:`MIME-Version` header (always set to ``1.0``). + + +.. class:: MIMENonMultipart() + + Module: :mod:`email.mime.nonmultipart` + + A subclass of :class:`MIMEBase`, this is an intermediate base class for MIME + messages that are not :mimetype:`multipart`. The primary purpose of this class + is to prevent the use of the :meth:`attach` method, which only makes sense for + :mimetype:`multipart` messages. If :meth:`attach` is called, a + :exc:`MultipartConversionError` exception is raised. + + .. versionadded:: 2.2.2 + + +.. class:: MIMEMultipart([subtype[, boundary[, _subparts[, _params]]]]) + + Module: :mod:`email.mime.multipart` + + A subclass of :class:`MIMEBase`, this is an intermediate base class for MIME + messages that are :mimetype:`multipart`. Optional *_subtype* defaults to + :mimetype:`mixed`, but can be used to specify the subtype of the message. A + :mailheader:`Content-Type` header of :mimetype:`multipart/`*_subtype* will be + added to the message object. A :mailheader:`MIME-Version` header will also be + added. + + Optional *boundary* is the multipart boundary string. When ``None`` (the + default), the boundary is calculated when needed. + + *_subparts* is a sequence of initial subparts for the payload. It must be + possible to convert this sequence to a list. You can always attach new subparts + to the message by using the :meth:`Message.attach` method. + + Additional parameters for the :mailheader:`Content-Type` header are taken from + the keyword arguments, or passed into the *_params* argument, which is a keyword + dictionary. + + .. versionadded:: 2.2.2 + + +.. class:: MIMEApplication(_data[, _subtype[, _encoder[, **_params]]]) + + Module: :mod:`email.mime.application` + + A subclass of :class:`MIMENonMultipart`, the :class:`MIMEApplication` class is + used to represent MIME message objects of major type :mimetype:`application`. + *_data* is a string containing the raw byte data. Optional *_subtype* specifies + the MIME subtype and defaults to :mimetype:`octet-stream`. + + Optional *_encoder* is a callable (i.e. function) which will perform the actual + encoding of the data for transport. This callable takes one argument, which is + the :class:`MIMEApplication` instance. It should use :meth:`get_payload` and + :meth:`set_payload` to change the payload to encoded form. It should also add + any :mailheader:`Content-Transfer-Encoding` or other headers to the message + object as necessary. The default encoding is base64. See the + :mod:`email.encoders` module for a list of the built-in encoders. + + *_params* are passed straight through to the base class constructor. + + .. versionadded:: 2.5 + + +.. class:: MIMEAudio(_audiodata[, _subtype[, _encoder[, **_params]]]) + + Module: :mod:`email.mime.audio` + + A subclass of :class:`MIMENonMultipart`, the :class:`MIMEAudio` class is used to + create MIME message objects of major type :mimetype:`audio`. *_audiodata* is a + string containing the raw audio data. If this data can be decoded by the + standard Python module :mod:`sndhdr`, then the subtype will be automatically + included in the :mailheader:`Content-Type` header. Otherwise you can explicitly + specify the audio subtype via the *_subtype* parameter. If the minor type could + not be guessed and *_subtype* was not given, then :exc:`TypeError` is raised. + + Optional *_encoder* is a callable (i.e. function) which will perform the actual + encoding of the audio data for transport. This callable takes one argument, + which is the :class:`MIMEAudio` instance. It should use :meth:`get_payload` and + :meth:`set_payload` to change the payload to encoded form. It should also add + any :mailheader:`Content-Transfer-Encoding` or other headers to the message + object as necessary. The default encoding is base64. See the + :mod:`email.encoders` module for a list of the built-in encoders. + + *_params* are passed straight through to the base class constructor. + + +.. class:: MIMEImage(_imagedata[, _subtype[, _encoder[, **_params]]]) + + Module: :mod:`email.mime.image` + + A subclass of :class:`MIMENonMultipart`, the :class:`MIMEImage` class is used to + create MIME message objects of major type :mimetype:`image`. *_imagedata* is a + string containing the raw image data. If this data can be decoded by the + standard Python module :mod:`imghdr`, then the subtype will be automatically + included in the :mailheader:`Content-Type` header. Otherwise you can explicitly + specify the image subtype via the *_subtype* parameter. If the minor type could + not be guessed and *_subtype* was not given, then :exc:`TypeError` is raised. + + Optional *_encoder* is a callable (i.e. function) which will perform the actual + encoding of the image data for transport. This callable takes one argument, + which is the :class:`MIMEImage` instance. It should use :meth:`get_payload` and + :meth:`set_payload` to change the payload to encoded form. It should also add + any :mailheader:`Content-Transfer-Encoding` or other headers to the message + object as necessary. The default encoding is base64. See the + :mod:`email.encoders` module for a list of the built-in encoders. + + *_params* are passed straight through to the :class:`MIMEBase` constructor. + + +.. class:: MIMEMessage(_msg[, _subtype]) + + Module: :mod:`email.mime.message` + + A subclass of :class:`MIMENonMultipart`, the :class:`MIMEMessage` class is used + to create MIME objects of main type :mimetype:`message`. *_msg* is used as the + payload, and must be an instance of class :class:`Message` (or a subclass + thereof), otherwise a :exc:`TypeError` is raised. + + Optional *_subtype* sets the subtype of the message; it defaults to + :mimetype:`rfc822`. + + +.. class:: MIMEText(_text[, _subtype[, _charset]]) + + Module: :mod:`email.mime.text` + + A subclass of :class:`MIMENonMultipart`, the :class:`MIMEText` class is used to + create MIME objects of major type :mimetype:`text`. *_text* is the string for + the payload. *_subtype* is the minor type and defaults to :mimetype:`plain`. + *_charset* is the character set of the text and is passed as a parameter to the + :class:`MIMENonMultipart` constructor; it defaults to ``us-ascii``. No guessing + or encoding is performed on the text data. + + .. versionchanged:: 2.4 + The previously deprecated *_encoding* argument has been removed. Encoding + happens implicitly based on the *_charset* argument. + diff --git a/Doc/library/email.parser.rst b/Doc/library/email.parser.rst new file mode 100644 index 0000000..048ed22 --- /dev/null +++ b/Doc/library/email.parser.rst @@ -0,0 +1,220 @@ +:mod:`email`: Parsing email messages +------------------------------------ + +.. module:: email.parser + :synopsis: Parse flat text email messages to produce a message object structure. + + +Message object structures can be created in one of two ways: they can be created +from whole cloth by instantiating :class:`Message` objects and stringing them +together via :meth:`attach` and :meth:`set_payload` calls, or they can be +created by parsing a flat text representation of the email message. + +The :mod:`email` package provides a standard parser that understands most email +document structures, including MIME documents. You can pass the parser a string +or a file object, and the parser will return to you the root :class:`Message` +instance of the object structure. For simple, non-MIME messages the payload of +this root object will likely be a string containing the text of the message. +For MIME messages, the root object will return ``True`` from its +:meth:`is_multipart` method, and the subparts can be accessed via the +:meth:`get_payload` and :meth:`walk` methods. + +There are actually two parser interfaces available for use, the classic +:class:`Parser` API and the incremental :class:`FeedParser` API. The classic +:class:`Parser` API is fine if you have the entire text of the message in memory +as a string, or if the entire message lives in a file on the file system. +:class:`FeedParser` is more appropriate for when you're reading the message from +a stream which might block waiting for more input (e.g. reading an email message +from a socket). The :class:`FeedParser` can consume and parse the message +incrementally, and only returns the root object when you close the parser [#]_. + +Note that the parser can be extended in limited ways, and of course you can +implement your own parser completely from scratch. There is no magical +connection between the :mod:`email` package's bundled parser and the +:class:`Message` class, so your custom parser can create message object trees +any way it finds necessary. + + +FeedParser API +^^^^^^^^^^^^^^ + +.. versionadded:: 2.4 + +The :class:`FeedParser`, imported from the :mod:`email.feedparser` module, +provides an API that is conducive to incremental parsing of email messages, such +as would be necessary when reading the text of an email message from a source +that can block (e.g. a socket). The :class:`FeedParser` can of course be used +to parse an email message fully contained in a string or a file, but the classic +:class:`Parser` API may be more convenient for such use cases. The semantics +and results of the two parser APIs are identical. + +The :class:`FeedParser`'s API is simple; you create an instance, feed it a bunch +of text until there's no more to feed it, then close the parser to retrieve the +root message object. The :class:`FeedParser` is extremely accurate when parsing +standards-compliant messages, and it does a very good job of parsing +non-compliant messages, providing information about how a message was deemed +broken. It will populate a message object's *defects* attribute with a list of +any problems it found in a message. See the :mod:`email.errors` module for the +list of defects that it can find. + +Here is the API for the :class:`FeedParser`: + + +.. class:: FeedParser([_factory]) + + Create a :class:`FeedParser` instance. Optional *_factory* is a no-argument + callable that will be called whenever a new message object is needed. It + defaults to the :class:`email.message.Message` class. + + +.. method:: FeedParser.feed(data) + + Feed the :class:`FeedParser` some more data. *data* should be a string + containing one or more lines. The lines can be partial and the + :class:`FeedParser` will stitch such partial lines together properly. The lines + in the string can have any of the common three line endings, carriage return, + newline, or carriage return and newline (they can even be mixed). + + +.. method:: FeedParser.close() + + Closing a :class:`FeedParser` completes the parsing of all previously fed data, + and returns the root message object. It is undefined what happens if you feed + more data to a closed :class:`FeedParser`. + + +Parser class API +^^^^^^^^^^^^^^^^ + +The :class:`Parser` class, imported from the :mod:`email.parser` module, +provides an API that can be used to parse a message when the complete contents +of the message are available in a string or file. The :mod:`email.parser` +module also provides a second class, called :class:`HeaderParser` which can be +used if you're only interested in the headers of the message. +:class:`HeaderParser` can be much faster in these situations, since it does not +attempt to parse the message body, instead setting the payload to the raw body +as a string. :class:`HeaderParser` has the same API as the :class:`Parser` +class. + + +.. class:: Parser([_class]) + + The constructor for the :class:`Parser` class takes an optional argument + *_class*. This must be a callable factory (such as a function or a class), and + it is used whenever a sub-message object needs to be created. It defaults to + :class:`Message` (see :mod:`email.message`). The factory will be called without + arguments. + + The optional *strict* flag is ignored. + + .. deprecated:: 2.4 + Because the :class:`Parser` class is a backward compatible API wrapper + around the new-in-Python 2.4 :class:`FeedParser`, *all* parsing is + effectively non-strict. You should simply stop passing a *strict* flag to + the :class:`Parser` constructor. + + .. versionchanged:: 2.2.2 + The *strict* flag was added. + + .. versionchanged:: 2.4 + The *strict* flag was deprecated. + +The other public :class:`Parser` methods are: + + +.. method:: Parser.parse(fp[, headersonly]) + + Read all the data from the file-like object *fp*, parse the resulting text, and + return the root message object. *fp* must support both the :meth:`readline` and + the :meth:`read` methods on file-like objects. + + The text contained in *fp* must be formatted as a block of :rfc:`2822` style + headers and header continuation lines, optionally preceded by a envelope + header. The header block is terminated either by the end of the data or by a + blank line. Following the header block is the body of the message (which may + contain MIME-encoded subparts). + + Optional *headersonly* is as with the :meth:`parse` method. + + .. versionchanged:: 2.2.2 + The *headersonly* flag was added. + + +.. method:: Parser.parsestr(text[, headersonly]) + + Similar to the :meth:`parse` method, except it takes a string object instead of + a file-like object. Calling this method on a string is exactly equivalent to + wrapping *text* in a :class:`StringIO` instance first and calling :meth:`parse`. + + Optional *headersonly* is a flag specifying whether to stop parsing after + reading the headers or not. The default is ``False``, meaning it parses the + entire contents of the file. + + .. versionchanged:: 2.2.2 + The *headersonly* flag was added. + +Since creating a message object structure from a string or a file object is such +a common task, two functions are provided as a convenience. They are available +in the top-level :mod:`email` package namespace. + + +.. function:: message_from_string(s[, _class[, strict]]) + + Return a message object structure from a string. This is exactly equivalent to + ``Parser().parsestr(s)``. Optional *_class* and *strict* are interpreted as + with the :class:`Parser` class constructor. + + .. versionchanged:: 2.2.2 + The *strict* flag was added. + + +.. function:: message_from_file(fp[, _class[, strict]]) + + Return a message object structure tree from an open file object. This is + exactly equivalent to ``Parser().parse(fp)``. Optional *_class* and *strict* + are interpreted as with the :class:`Parser` class constructor. + + .. versionchanged:: 2.2.2 + The *strict* flag was added. + +Here's an example of how you might use this at an interactive Python prompt:: + + >>> import email + >>> msg = email.message_from_string(myString) + + +Additional notes +^^^^^^^^^^^^^^^^ + +Here are some notes on the parsing semantics: + +* Most non-\ :mimetype:`multipart` type messages are parsed as a single message + object with a string payload. These objects will return ``False`` for + :meth:`is_multipart`. Their :meth:`get_payload` method will return a string + object. + +* All :mimetype:`multipart` type messages will be parsed as a container message + object with a list of sub-message objects for their payload. The outer + container message will return ``True`` for :meth:`is_multipart` and their + :meth:`get_payload` method will return the list of :class:`Message` subparts. + +* Most messages with a content type of :mimetype:`message/\*` (e.g. + :mimetype:`message/delivery-status` and :mimetype:`message/rfc822`) will also be + parsed as container object containing a list payload of length 1. Their + :meth:`is_multipart` method will return ``True``. The single element in the + list payload will be a sub-message object. + +* Some non-standards compliant messages may not be internally consistent about + their :mimetype:`multipart`\ -edness. Such messages may have a + :mailheader:`Content-Type` header of type :mimetype:`multipart`, but their + :meth:`is_multipart` method may return ``False``. If such messages were parsed + with the :class:`FeedParser`, they will have an instance of the + :class:`MultipartInvariantViolationDefect` class in their *defects* attribute + list. See :mod:`email.errors` for details. + +.. rubric:: Footnotes + +.. [#] As of email package version 3.0, introduced in Python 2.4, the classic + :class:`Parser` was re-implemented in terms of the :class:`FeedParser`, so the + semantics and results are identical between the two parsers. + diff --git a/Doc/library/email.rst b/Doc/library/email.rst new file mode 100644 index 0000000..212c321 --- /dev/null +++ b/Doc/library/email.rst @@ -0,0 +1,324 @@ +.. % Copyright (C) 2001-2007 Python Software Foundation +.. % Author: barry@python.org (Barry Warsaw) + + +:mod:`email` --- An email and MIME handling package +=================================================== + +.. module:: email + :synopsis: Package supporting the parsing, manipulating, and generating email messages, + including MIME documents. +.. moduleauthor:: Barry A. Warsaw +.. sectionauthor:: Barry A. Warsaw + + +.. versionadded:: 2.2 + +The :mod:`email` package is a library for managing email messages, including +MIME and other :rfc:`2822`\ -based message documents. It subsumes most of the +functionality in several older standard modules such as :mod:`rfc822`, +:mod:`mimetools`, :mod:`multifile`, and other non-standard packages such as +:mod:`mimecntl`. It is specifically *not* designed to do any sending of email +messages to SMTP (:rfc:`2821`), NNTP, or other servers; those are functions of +modules such as :mod:`smtplib` and :mod:`nntplib`. The :mod:`email` package +attempts to be as RFC-compliant as possible, supporting in addition to +:rfc:`2822`, such MIME-related RFCs as :rfc:`2045`, :rfc:`2046`, :rfc:`2047`, +and :rfc:`2231`. + +The primary distinguishing feature of the :mod:`email` package is that it splits +the parsing and generating of email messages from the internal *object model* +representation of email. Applications using the :mod:`email` package deal +primarily with objects; you can add sub-objects to messages, remove sub-objects +from messages, completely re-arrange the contents, etc. There is a separate +parser and a separate generator which handles the transformation from flat text +to the object model, and then back to flat text again. There are also handy +subclasses for some common MIME object types, and a few miscellaneous utilities +that help with such common tasks as extracting and parsing message field values, +creating RFC-compliant dates, etc. + +The following sections describe the functionality of the :mod:`email` package. +The ordering follows a progression that should be common in applications: an +email message is read as flat text from a file or other source, the text is +parsed to produce the object structure of the email message, this structure is +manipulated, and finally, the object tree is rendered back into flat text. + +It is perfectly feasible to create the object structure out of whole cloth --- +i.e. completely from scratch. From there, a similar progression can be taken as +above. + +Also included are detailed specifications of all the classes and modules that +the :mod:`email` package provides, the exception classes you might encounter +while using the :mod:`email` package, some auxiliary utilities, and a few +examples. For users of the older :mod:`mimelib` package, or previous versions +of the :mod:`email` package, a section on differences and porting is provided. + +Contents of the :mod:`email` package documentation: + +.. toctree:: + + email.message.rst + email.parser.rst + email.generator.rst + email.mime.rst + email.header.rst + email.charset.rst + email.encoders.rst + email.errors.rst + email.util.rst + email.iterators.rst + email-examples.rst + + +.. seealso:: + + Module :mod:`smtplib` + SMTP protocol client + + Module :mod:`nntplib` + NNTP protocol client + + +.. _email-pkg-history: + +Package History +--------------- + +This table describes the release history of the email package, corresponding to +the version of Python that the package was released with. For purposes of this +document, when you see a note about change or added versions, these refer to the +Python version the change was made in, *not* the email package version. This +table also describes the Python compatibility of each version of the package. + ++---------------+------------------------------+-----------------------+ +| email version | distributed with | compatible with | ++===============+==============================+=======================+ +| :const:`1.x` | Python 2.2.0 to Python 2.2.1 | *no longer supported* | ++---------------+------------------------------+-----------------------+ +| :const:`2.5` | Python 2.2.2+ and Python 2.3 | Python 2.1 to 2.5 | ++---------------+------------------------------+-----------------------+ +| :const:`3.0` | Python 2.4 | Python 2.3 to 2.5 | ++---------------+------------------------------+-----------------------+ +| :const:`4.0` | Python 2.5 | Python 2.3 to 2.5 | ++---------------+------------------------------+-----------------------+ + +Here are the major differences between :mod:`email` version 4 and version 3: + +* All modules have been renamed according to :pep:`8` standards. For example, + the version 3 module :mod:`email.Message` was renamed to :mod:`email.message` in + version 4. + +* A new subpackage :mod:`email.mime` was added and all the version 3 + :mod:`email.MIME\*` modules were renamed and situated into the :mod:`email.mime` + subpackage. For example, the version 3 module :mod:`email.MIMEText` was renamed + to :mod:`email.mime.text`. + + *Note that the version 3 names will continue to work until Python 2.6*. + +* The :mod:`email.mime.application` module was added, which contains the + :class:`MIMEApplication` class. + +* Methods that were deprecated in version 3 have been removed. These include + :meth:`Generator.__call__`, :meth:`Message.get_type`, + :meth:`Message.get_main_type`, :meth:`Message.get_subtype`. + +* Fixes have been added for :rfc:`2231` support which can change some of the + return types for :func:`Message.get_param` and friends. Under some + circumstances, values which used to return a 3-tuple now return simple strings + (specifically, if all extended parameter segments were unencoded, there is no + language and charset designation expected, so the return type is now a simple + string). Also, %-decoding used to be done for both encoded and unencoded + segments; this decoding is now done only for encoded segments. + +Here are the major differences between :mod:`email` version 3 and version 2: + +* The :class:`FeedParser` class was introduced, and the :class:`Parser` class + was implemented in terms of the :class:`FeedParser`. All parsing therefore is + non-strict, and parsing will make a best effort never to raise an exception. + Problems found while parsing messages are stored in the message's *defect* + attribute. + +* All aspects of the API which raised :exc:`DeprecationWarning`\ s in version 2 + have been removed. These include the *_encoder* argument to the + :class:`MIMEText` constructor, the :meth:`Message.add_payload` method, the + :func:`Utils.dump_address_pair` function, and the functions :func:`Utils.decode` + and :func:`Utils.encode`. + +* New :exc:`DeprecationWarning`\ s have been added to: + :meth:`Generator.__call__`, :meth:`Message.get_type`, + :meth:`Message.get_main_type`, :meth:`Message.get_subtype`, and the *strict* + argument to the :class:`Parser` class. These are expected to be removed in + future versions. + +* Support for Pythons earlier than 2.3 has been removed. + +Here are the differences between :mod:`email` version 2 and version 1: + +* The :mod:`email.Header` and :mod:`email.Charset` modules have been added. + +* The pickle format for :class:`Message` instances has changed. Since this was + never (and still isn't) formally defined, this isn't considered a backward + incompatibility. However if your application pickles and unpickles + :class:`Message` instances, be aware that in :mod:`email` version 2, + :class:`Message` instances now have private variables *_charset* and + *_default_type*. + +* Several methods in the :class:`Message` class have been deprecated, or their + signatures changed. Also, many new methods have been added. See the + documentation for the :class:`Message` class for details. The changes should be + completely backward compatible. + +* The object structure has changed in the face of :mimetype:`message/rfc822` + content types. In :mod:`email` version 1, such a type would be represented by a + scalar payload, i.e. the container message's :meth:`is_multipart` returned + false, :meth:`get_payload` was not a list object, but a single :class:`Message` + instance. + + This structure was inconsistent with the rest of the package, so the object + representation for :mimetype:`message/rfc822` content types was changed. In + :mod:`email` version 2, the container *does* return ``True`` from + :meth:`is_multipart`, and :meth:`get_payload` returns a list containing a single + :class:`Message` item. + + Note that this is one place that backward compatibility could not be completely + maintained. However, if you're already testing the return type of + :meth:`get_payload`, you should be fine. You just need to make sure your code + doesn't do a :meth:`set_payload` with a :class:`Message` instance on a container + with a content type of :mimetype:`message/rfc822`. + +* The :class:`Parser` constructor's *strict* argument was added, and its + :meth:`parse` and :meth:`parsestr` methods grew a *headersonly* argument. The + *strict* flag was also added to functions :func:`email.message_from_file` and + :func:`email.message_from_string`. + +* :meth:`Generator.__call__` is deprecated; use :meth:`Generator.flatten` + instead. The :class:`Generator` class has also grown the :meth:`clone` method. + +* The :class:`DecodedGenerator` class in the :mod:`email.Generator` module was + added. + +* The intermediate base classes :class:`MIMENonMultipart` and + :class:`MIMEMultipart` have been added, and interposed in the class hierarchy + for most of the other MIME-related derived classes. + +* The *_encoder* argument to the :class:`MIMEText` constructor has been + deprecated. Encoding now happens implicitly based on the *_charset* argument. + +* The following functions in the :mod:`email.Utils` module have been deprecated: + :func:`dump_address_pairs`, :func:`decode`, and :func:`encode`. The following + functions have been added to the module: :func:`make_msgid`, + :func:`decode_rfc2231`, :func:`encode_rfc2231`, and :func:`decode_params`. + +* The non-public function :func:`email.Iterators._structure` was added. + + +Differences from :mod:`mimelib` +------------------------------- + +The :mod:`email` package was originally prototyped as a separate library called +`mimelib `_. Changes have been made so that method names +are more consistent, and some methods or modules have either been added or +removed. The semantics of some of the methods have also changed. For the most +part, any functionality available in :mod:`mimelib` is still available in the +:mod:`email` package, albeit often in a different way. Backward compatibility +between the :mod:`mimelib` package and the :mod:`email` package was not a +priority. + +Here is a brief description of the differences between the :mod:`mimelib` and +the :mod:`email` packages, along with hints on how to port your applications. + +Of course, the most visible difference between the two packages is that the +package name has been changed to :mod:`email`. In addition, the top-level +package has the following differences: + +* :func:`messageFromString` has been renamed to :func:`message_from_string`. + +* :func:`messageFromFile` has been renamed to :func:`message_from_file`. + +The :class:`Message` class has the following differences: + +* The method :meth:`asString` was renamed to :meth:`as_string`. + +* The method :meth:`ismultipart` was renamed to :meth:`is_multipart`. + +* The :meth:`get_payload` method has grown a *decode* optional argument. + +* The method :meth:`getall` was renamed to :meth:`get_all`. + +* The method :meth:`addheader` was renamed to :meth:`add_header`. + +* The method :meth:`gettype` was renamed to :meth:`get_type`. + +* The method :meth:`getmaintype` was renamed to :meth:`get_main_type`. + +* The method :meth:`getsubtype` was renamed to :meth:`get_subtype`. + +* The method :meth:`getparams` was renamed to :meth:`get_params`. Also, whereas + :meth:`getparams` returned a list of strings, :meth:`get_params` returns a list + of 2-tuples, effectively the key/value pairs of the parameters, split on the + ``'='`` sign. + +* The method :meth:`getparam` was renamed to :meth:`get_param`. + +* The method :meth:`getcharsets` was renamed to :meth:`get_charsets`. + +* The method :meth:`getfilename` was renamed to :meth:`get_filename`. + +* The method :meth:`getboundary` was renamed to :meth:`get_boundary`. + +* The method :meth:`setboundary` was renamed to :meth:`set_boundary`. + +* The method :meth:`getdecodedpayload` was removed. To get similar + functionality, pass the value 1 to the *decode* flag of the get_payload() + method. + +* The method :meth:`getpayloadastext` was removed. Similar functionality is + supported by the :class:`DecodedGenerator` class in the :mod:`email.generator` + module. + +* The method :meth:`getbodyastext` was removed. You can get similar + functionality by creating an iterator with :func:`typed_subpart_iterator` in the + :mod:`email.iterators` module. + +The :class:`Parser` class has no differences in its public interface. It does +have some additional smarts to recognize :mimetype:`message/delivery-status` +type messages, which it represents as a :class:`Message` instance containing +separate :class:`Message` subparts for each header block in the delivery status +notification [#]_. + +The :class:`Generator` class has no differences in its public interface. There +is a new class in the :mod:`email.generator` module though, called +:class:`DecodedGenerator` which provides most of the functionality previously +available in the :meth:`Message.getpayloadastext` method. + +The following modules and classes have been changed: + +* The :class:`MIMEBase` class constructor arguments *_major* and *_minor* have + changed to *_maintype* and *_subtype* respectively. + +* The ``Image`` class/module has been renamed to ``MIMEImage``. The *_minor* + argument has been renamed to *_subtype*. + +* The ``Text`` class/module has been renamed to ``MIMEText``. The *_minor* + argument has been renamed to *_subtype*. + +* The ``MessageRFC822`` class/module has been renamed to ``MIMEMessage``. Note + that an earlier version of :mod:`mimelib` called this class/module ``RFC822``, + but that clashed with the Python standard library module :mod:`rfc822` on some + case-insensitive file systems. + + Also, the :class:`MIMEMessage` class now represents any kind of MIME message + with main type :mimetype:`message`. It takes an optional argument *_subtype* + which is used to set the MIME subtype. *_subtype* defaults to + :mimetype:`rfc822`. + +:mod:`mimelib` provided some utility functions in its :mod:`address` and +:mod:`date` modules. All of these functions have been moved to the +:mod:`email.utils` module. + +The ``MsgReader`` class/module has been removed. Its functionality is most +closely supported in the :func:`body_line_iterator` function in the +:mod:`email.iterators` module. + +.. rubric:: Footnotes + +.. [#] Delivery Status Notifications (DSN) are defined in :rfc:`1894`. diff --git a/Doc/library/email.util.rst b/Doc/library/email.util.rst new file mode 100644 index 0000000..aa67885 --- /dev/null +++ b/Doc/library/email.util.rst @@ -0,0 +1,166 @@ +:mod:`email`: Miscellaneous utilities +------------------------------------- + +.. module:: email.utils + :synopsis: Miscellaneous email package utilities. + + +There are several useful utilities provided in the :mod:`email.utils` module: + + +.. function:: quote(str) + + Return a new string with backslashes in *str* replaced by two backslashes, and + double quotes replaced by backslash-double quote. + + +.. function:: unquote(str) + + Return a new string which is an *unquoted* version of *str*. If *str* ends and + begins with double quotes, they are stripped off. Likewise if *str* ends and + begins with angle brackets, they are stripped off. + + +.. function:: parseaddr(address) + + Parse address -- which should be the value of some address-containing field such + as :mailheader:`To` or :mailheader:`Cc` -- into its constituent *realname* and + *email address* parts. Returns a tuple of that information, unless the parse + fails, in which case a 2-tuple of ``('', '')`` is returned. + + +.. function:: formataddr(pair) + + The inverse of :meth:`parseaddr`, this takes a 2-tuple of the form ``(realname, + email_address)`` and returns the string value suitable for a :mailheader:`To` or + :mailheader:`Cc` header. If the first element of *pair* is false, then the + second element is returned unmodified. + + +.. function:: getaddresses(fieldvalues) + + This method returns a list of 2-tuples of the form returned by ``parseaddr()``. + *fieldvalues* is a sequence of header field values as might be returned by + :meth:`Message.get_all`. Here's a simple example that gets all the recipients + of a message:: + + from email.utils import getaddresses + + tos = msg.get_all('to', []) + ccs = msg.get_all('cc', []) + resent_tos = msg.get_all('resent-to', []) + resent_ccs = msg.get_all('resent-cc', []) + all_recipients = getaddresses(tos + ccs + resent_tos + resent_ccs) + + +.. function:: parsedate(date) + + Attempts to parse a date according to the rules in :rfc:`2822`. however, some + mailers don't follow that format as specified, so :func:`parsedate` tries to + guess correctly in such cases. *date* is a string containing an :rfc:`2822` + date, such as ``"Mon, 20 Nov 1995 19:12:08 -0500"``. If it succeeds in parsing + the date, :func:`parsedate` returns a 9-tuple that can be passed directly to + :func:`time.mktime`; otherwise ``None`` will be returned. Note that indexes 6, + 7, and 8 of the result tuple are not usable. + + +.. function:: parsedate_tz(date) + + Performs the same function as :func:`parsedate`, but returns either ``None`` or + a 10-tuple; the first 9 elements make up a tuple that can be passed directly to + :func:`time.mktime`, and the tenth is the offset of the date's timezone from UTC + (which is the official term for Greenwich Mean Time) [#]_. If the input string + has no timezone, the last element of the tuple returned is ``None``. Note that + indexes 6, 7, and 8 of the result tuple are not usable. + + +.. function:: mktime_tz(tuple) + + Turn a 10-tuple as returned by :func:`parsedate_tz` into a UTC timestamp. It + the timezone item in the tuple is ``None``, assume local time. Minor + deficiency: :func:`mktime_tz` interprets the first 8 elements of *tuple* as a + local time and then compensates for the timezone difference. This may yield a + slight error around changes in daylight savings time, though not worth worrying + about for common use. + + +.. function:: formatdate([timeval[, localtime][, usegmt]]) + + Returns a date string as per :rfc:`2822`, e.g.:: + + Fri, 09 Nov 2001 01:08:47 -0000 + + Optional *timeval* if given is a floating point time value as accepted by + :func:`time.gmtime` and :func:`time.localtime`, otherwise the current time is + used. + + Optional *localtime* is a flag that when ``True``, interprets *timeval*, and + returns a date relative to the local timezone instead of UTC, properly taking + daylight savings time into account. The default is ``False`` meaning UTC is + used. + + Optional *usegmt* is a flag that when ``True``, outputs a date string with the + timezone as an ascii string ``GMT``, rather than a numeric ``-0000``. This is + needed for some protocols (such as HTTP). This only applies when *localtime* is + ``False``. + + .. versionadded:: 2.4 + + +.. function:: make_msgid([idstring]) + + Returns a string suitable for an :rfc:`2822`\ -compliant + :mailheader:`Message-ID` header. Optional *idstring* if given, is a string used + to strengthen the uniqueness of the message id. + + +.. function:: decode_rfc2231(s) + + Decode the string *s* according to :rfc:`2231`. + + +.. function:: encode_rfc2231(s[, charset[, language]]) + + Encode the string *s* according to :rfc:`2231`. Optional *charset* and + *language*, if given is the character set name and language name to use. If + neither is given, *s* is returned as-is. If *charset* is given but *language* + is not, the string is encoded using the empty string for *language*. + + +.. function:: collapse_rfc2231_value(value[, errors[, fallback_charset]]) + + When a header parameter is encoded in :rfc:`2231` format, + :meth:`Message.get_param` may return a 3-tuple containing the character set, + language, and value. :func:`collapse_rfc2231_value` turns this into a unicode + string. Optional *errors* is passed to the *errors* argument of the built-in + :func:`unicode` function; it defaults to ``replace``. Optional + *fallback_charset* specifies the character set to use if the one in the + :rfc:`2231` header is not known by Python; it defaults to ``us-ascii``. + + For convenience, if the *value* passed to :func:`collapse_rfc2231_value` is not + a tuple, it should be a string and it is returned unquoted. + + +.. function:: decode_params(params) + + Decode parameters list according to :rfc:`2231`. *params* is a sequence of + 2-tuples containing elements of the form ``(content-type, string-value)``. + +.. versionchanged:: 2.4 + The :func:`dump_address_pair` function has been removed; use :func:`formataddr` + instead. + +.. versionchanged:: 2.4 + The :func:`decode` function has been removed; use the + :meth:`Header.decode_header` method instead. + +.. versionchanged:: 2.4 + The :func:`encode` function has been removed; use the :meth:`Header.encode` + method instead. + +.. rubric:: Footnotes + +.. [#] Note that the sign of the timezone offset is the opposite of the sign of the + ``time.timezone`` variable for the same timezone; the latter variable follows + the POSIX standard while this module follows :rfc:`2822`. + diff --git a/Doc/library/errno.rst b/Doc/library/errno.rst new file mode 100644 index 0000000..daf9ff0 --- /dev/null +++ b/Doc/library/errno.rst @@ -0,0 +1,636 @@ + +:mod:`errno` --- Standard errno system symbols +============================================== + +.. module:: errno + :synopsis: Standard errno system symbols. + + +This module makes available standard ``errno`` system symbols. The value of each +symbol is the corresponding integer value. The names and descriptions are +borrowed from :file:`linux/include/errno.h`, which should be pretty +all-inclusive. + + +.. data:: errorcode + + Dictionary providing a mapping from the errno value to the string name in the + underlying system. For instance, ``errno.errorcode[errno.EPERM]`` maps to + ``'EPERM'``. + +To translate a numeric error code to an error message, use :func:`os.strerror`. + +Of the following list, symbols that are not used on the current platform are not +defined by the module. The specific list of defined symbols is available as +``errno.errorcode.keys()``. Symbols available can include: + + +.. data:: EPERM + + Operation not permitted + + +.. data:: ENOENT + + No such file or directory + + +.. data:: ESRCH + + No such process + + +.. data:: EINTR + + Interrupted system call + + +.. data:: EIO + + I/O error + + +.. data:: ENXIO + + No such device or address + + +.. data:: E2BIG + + Arg list too long + + +.. data:: ENOEXEC + + Exec format error + + +.. data:: EBADF + + Bad file number + + +.. data:: ECHILD + + No child processes + + +.. data:: EAGAIN + + Try again + + +.. data:: ENOMEM + + Out of memory + + +.. data:: EACCES + + Permission denied + + +.. data:: EFAULT + + Bad address + + +.. data:: ENOTBLK + + Block device required + + +.. data:: EBUSY + + Device or resource busy + + +.. data:: EEXIST + + File exists + + +.. data:: EXDEV + + Cross-device link + + +.. data:: ENODEV + + No such device + + +.. data:: ENOTDIR + + Not a directory + + +.. data:: EISDIR + + Is a directory + + +.. data:: EINVAL + + Invalid argument + + +.. data:: ENFILE + + File table overflow + + +.. data:: EMFILE + + Too many open files + + +.. data:: ENOTTY + + Not a typewriter + + +.. data:: ETXTBSY + + Text file busy + + +.. data:: EFBIG + + File too large + + +.. data:: ENOSPC + + No space left on device + + +.. data:: ESPIPE + + Illegal seek + + +.. data:: EROFS + + Read-only file system + + +.. data:: EMLINK + + Too many links + + +.. data:: EPIPE + + Broken pipe + + +.. data:: EDOM + + Math argument out of domain of func + + +.. data:: ERANGE + + Math result not representable + + +.. data:: EDEADLK + + Resource deadlock would occur + + +.. data:: ENAMETOOLONG + + File name too long + + +.. data:: ENOLCK + + No record locks available + + +.. data:: ENOSYS + + Function not implemented + + +.. data:: ENOTEMPTY + + Directory not empty + + +.. data:: ELOOP + + Too many symbolic links encountered + + +.. data:: EWOULDBLOCK + + Operation would block + + +.. data:: ENOMSG + + No message of desired type + + +.. data:: EIDRM + + Identifier removed + + +.. data:: ECHRNG + + Channel number out of range + + +.. data:: EL2NSYNC + + Level 2 not synchronized + + +.. data:: EL3HLT + + Level 3 halted + + +.. data:: EL3RST + + Level 3 reset + + +.. data:: ELNRNG + + Link number out of range + + +.. data:: EUNATCH + + Protocol driver not attached + + +.. data:: ENOCSI + + No CSI structure available + + +.. data:: EL2HLT + + Level 2 halted + + +.. data:: EBADE + + Invalid exchange + + +.. data:: EBADR + + Invalid request descriptor + + +.. data:: EXFULL + + Exchange full + + +.. data:: ENOANO + + No anode + + +.. data:: EBADRQC + + Invalid request code + + +.. data:: EBADSLT + + Invalid slot + + +.. data:: EDEADLOCK + + File locking deadlock error + + +.. data:: EBFONT + + Bad font file format + + +.. data:: ENOSTR + + Device not a stream + + +.. data:: ENODATA + + No data available + + +.. data:: ETIME + + Timer expired + + +.. data:: ENOSR + + Out of streams resources + + +.. data:: ENONET + + Machine is not on the network + + +.. data:: ENOPKG + + Package not installed + + +.. data:: EREMOTE + + Object is remote + + +.. data:: ENOLINK + + Link has been severed + + +.. data:: EADV + + Advertise error + + +.. data:: ESRMNT + + Srmount error + + +.. data:: ECOMM + + Communication error on send + + +.. data:: EPROTO + + Protocol error + + +.. data:: EMULTIHOP + + Multihop attempted + + +.. data:: EDOTDOT + + RFS specific error + + +.. data:: EBADMSG + + Not a data message + + +.. data:: EOVERFLOW + + Value too large for defined data type + + +.. data:: ENOTUNIQ + + Name not unique on network + + +.. data:: EBADFD + + File descriptor in bad state + + +.. data:: EREMCHG + + Remote address changed + + +.. data:: ELIBACC + + Can not access a needed shared library + + +.. data:: ELIBBAD + + Accessing a corrupted shared library + + +.. data:: ELIBSCN + + .lib section in a.out corrupted + + +.. data:: ELIBMAX + + Attempting to link in too many shared libraries + + +.. data:: ELIBEXEC + + Cannot exec a shared library directly + + +.. data:: EILSEQ + + Illegal byte sequence + + +.. data:: ERESTART + + Interrupted system call should be restarted + + +.. data:: ESTRPIPE + + Streams pipe error + + +.. data:: EUSERS + + Too many users + + +.. data:: ENOTSOCK + + Socket operation on non-socket + + +.. data:: EDESTADDRREQ + + Destination address required + + +.. data:: EMSGSIZE + + Message too long + + +.. data:: EPROTOTYPE + + Protocol wrong type for socket + + +.. data:: ENOPROTOOPT + + Protocol not available + + +.. data:: EPROTONOSUPPORT + + Protocol not supported + + +.. data:: ESOCKTNOSUPPORT + + Socket type not supported + + +.. data:: EOPNOTSUPP + + Operation not supported on transport endpoint + + +.. data:: EPFNOSUPPORT + + Protocol family not supported + + +.. data:: EAFNOSUPPORT + + Address family not supported by protocol + + +.. data:: EADDRINUSE + + Address already in use + + +.. data:: EADDRNOTAVAIL + + Cannot assign requested address + + +.. data:: ENETDOWN + + Network is down + + +.. data:: ENETUNREACH + + Network is unreachable + + +.. data:: ENETRESET + + Network dropped connection because of reset + + +.. data:: ECONNABORTED + + Software caused connection abort + + +.. data:: ECONNRESET + + Connection reset by peer + + +.. data:: ENOBUFS + + No buffer space available + + +.. data:: EISCONN + + Transport endpoint is already connected + + +.. data:: ENOTCONN + + Transport endpoint is not connected + + +.. data:: ESHUTDOWN + + Cannot send after transport endpoint shutdown + + +.. data:: ETOOMANYREFS + + Too many references: cannot splice + + +.. data:: ETIMEDOUT + + Connection timed out + + +.. data:: ECONNREFUSED + + Connection refused + + +.. data:: EHOSTDOWN + + Host is down + + +.. data:: EHOSTUNREACH + + No route to host + + +.. data:: EALREADY + + Operation already in progress + + +.. data:: EINPROGRESS + + Operation now in progress + + +.. data:: ESTALE + + Stale NFS file handle + + +.. data:: EUCLEAN + + Structure needs cleaning + + +.. data:: ENOTNAM + + Not a XENIX named type file + + +.. data:: ENAVAIL + + No XENIX semaphores available + + +.. data:: EISNAM + + Is a named type file + + +.. data:: EREMOTEIO + + Remote I/O error + + +.. data:: EDQUOT + + Quota exceeded + diff --git a/Doc/library/exceptions.rst b/Doc/library/exceptions.rst new file mode 100644 index 0000000..d6a64fc --- /dev/null +++ b/Doc/library/exceptions.rst @@ -0,0 +1,475 @@ +.. _bltin-exceptions: + +Built-in Exceptions +=================== + +.. module:: exceptions + :synopsis: Standard exception classes. + + +Exceptions should be class objects. The exceptions are defined in the module +:mod:`exceptions`. This module never needs to be imported explicitly: the +exceptions are provided in the built-in namespace as well as the +:mod:`exceptions` module. + +.. index:: + statement: try + statement: except + +For class exceptions, in a :keyword:`try` statement with an :keyword:`except` +clause that mentions a particular class, that clause also handles any exception +classes derived from that class (but not exception classes from which *it* is +derived). Two exception classes that are not related via subclassing are never +equivalent, even if they have the same name. + +.. index:: statement: raise + +The built-in exceptions listed below can be generated by the interpreter or +built-in functions. Except where mentioned, they have an "associated value" +indicating the detailed cause of the error. This may be a string or a tuple +containing several items of information (e.g., an error code and a string +explaining the code). The associated value is the second argument to the +:keyword:`raise` statement. If the exception class is derived from the standard +root class :exc:`BaseException`, the associated value is present as the +exception instance's :attr:`args` attribute. + +User code can raise built-in exceptions. This can be used to test an exception +handler or to report an error condition "just like" the situation in which the +interpreter raises the same exception; but beware that there is nothing to +prevent user code from raising an inappropriate error. + +The built-in exception classes can be sub-classed to define new exceptions; +programmers are encouraged to at least derive new exceptions from the +:exc:`Exception` class and not :exc:`BaseException`. More information on +defining exceptions is available in the Python Tutorial under +:ref:`tut-userexceptions`. + +The following exceptions are only used as base classes for other exceptions. + + +.. exception:: BaseException + + The base class for all built-in exceptions. It is not meant to be directly + inherited by user-defined classes (for that use :exc:`Exception`). If + :func:`str` or :func:`unicode` is called on an instance of this class, the + representation of the argument(s) to the instance are returned or the emptry + string when there were no arguments. All arguments are stored in :attr:`args` + as a tuple. + + .. versionadded:: 2.5 + + +.. exception:: Exception + + All built-in, non-system-exiting exceptions are derived from this class. All + user-defined exceptions should also be derived from this class. + + .. versionchanged:: 2.5 + Changed to inherit from :exc:`BaseException`. + + +.. exception:: ArithmeticError + + The base class for those built-in exceptions that are raised for various + arithmetic errors: :exc:`OverflowError`, :exc:`ZeroDivisionError`, + :exc:`FloatingPointError`. + + +.. exception:: LookupError + + The base class for the exceptions that are raised when a key or index used on a + mapping or sequence is invalid: :exc:`IndexError`, :exc:`KeyError`. This can be + raised directly by :func:`sys.setdefaultencoding`. + + +.. exception:: EnvironmentError + + The base class for exceptions that can occur outside the Python system: + :exc:`IOError`, :exc:`OSError`. When exceptions of this type are created with a + 2-tuple, the first item is available on the instance's :attr:`errno` attribute + (it is assumed to be an error number), and the second item is available on the + :attr:`strerror` attribute (it is usually the associated error message). The + tuple itself is also available on the :attr:`args` attribute. + + .. versionadded:: 1.5.2 + + When an :exc:`EnvironmentError` exception is instantiated with a 3-tuple, the + first two items are available as above, while the third item is available on the + :attr:`filename` attribute. However, for backwards compatibility, the + :attr:`args` attribute contains only a 2-tuple of the first two constructor + arguments. + + The :attr:`filename` attribute is ``None`` when this exception is created with + other than 3 arguments. The :attr:`errno` and :attr:`strerror` attributes are + also ``None`` when the instance was created with other than 2 or 3 arguments. + In this last case, :attr:`args` contains the verbatim constructor arguments as a + tuple. + +The following exceptions are the exceptions that are actually raised. + + +.. exception:: AssertionError + + .. index:: statement: assert + + Raised when an :keyword:`assert` statement fails. + + +.. exception:: AttributeError + + Raised when an attribute reference or assignment fails. (When an object does + not support attribute references or attribute assignments at all, + :exc:`TypeError` is raised.) + + .. % xref to attribute reference? + + +.. exception:: EOFError + + Raised when attempting to read beyond the end of a file. (N.B.: the :meth:`read` + and :meth:`readline` methods of file objects return an empty string when they + hit EOF.) + + .. % XXXJH xrefs here + .. % XXXJH xrefs here + + +.. exception:: FloatingPointError + + Raised when a floating point operation fails. This exception is always defined, + but can only be raised when Python is configured with the + :option:`--with-fpectl` option, or the :const:`WANT_SIGFPE_HANDLER` symbol is + defined in the :file:`pyconfig.h` file. + + +.. exception:: GeneratorExit + + Raise when a generator's :meth:`close` method is called. + + .. versionadded:: 2.5 + + .. versionchanged:: 3.0 + Changed to inherit from Exception instead of StandardError. + + +.. exception:: IOError + + Raised when an I/O operation (such as a :keyword:`print` statement, the built-in + :func:`open` function or a method of a file object) fails for an I/O-related + reason, e.g., "file not found" or "disk full". + + .. % XXXJH xrefs here + + This class is derived from :exc:`EnvironmentError`. See the discussion above + for more information on exception instance attributes. + + +.. exception:: ImportError + + Raised when an :keyword:`import` statement fails to find the module definition + or when a ``from ... import`` fails to find a name that is to be imported. + + .. % XXXJH xref to import statement? + + +.. exception:: IndexError + + Raised when a sequence subscript is out of range. (Slice indices are silently + truncated to fall in the allowed range; if an index is not a plain integer, + :exc:`TypeError` is raised.) + + .. % XXXJH xref to sequences + + +.. exception:: KeyError + + Raised when a mapping (dictionary) key is not found in the set of existing keys. + + .. % XXXJH xref to mapping objects? + + +.. exception:: KeyboardInterrupt + + Raised when the user hits the interrupt key (normally :kbd:`Control-C` or + :kbd:`Delete`). During execution, a check for interrupts is made regularly. The + exception inherits from :exc:`BaseException` so as to not be accidentally caught + by code that catches :exc:`Exception` and thus prevent the interpreter from + exiting. + + .. % XXX(hylton) xrefs here + + .. versionchanged:: 2.5 + Changed to inherit from :exc:`BaseException`. + + +.. exception:: MemoryError + + Raised when an operation runs out of memory but the situation may still be + rescued (by deleting some objects). The associated value is a string indicating + what kind of (internal) operation ran out of memory. Note that because of the + underlying memory management architecture (C's :cfunc:`malloc` function), the + interpreter may not always be able to completely recover from this situation; it + nevertheless raises an exception so that a stack traceback can be printed, in + case a run-away program was the cause. + + +.. exception:: NameError + + Raised when a local or global name is not found. This applies only to + unqualified names. The associated value is an error message that includes the + name that could not be found. + + +.. exception:: NotImplementedError + + This exception is derived from :exc:`RuntimeError`. In user defined base + classes, abstract methods should raise this exception when they require derived + classes to override the method. + + .. versionadded:: 1.5.2 + + +.. exception:: OSError + + This class is derived from :exc:`EnvironmentError` and is used primarily as the + :mod:`os` module's ``os.error`` exception. See :exc:`EnvironmentError` above for + a description of the possible associated values. + + .. % xref for os module + + .. versionadded:: 1.5.2 + + +.. exception:: OverflowError + + Raised when the result of an arithmetic operation is too large to be + represented. This cannot occur for long integers (which would rather raise + :exc:`MemoryError` than give up). Because of the lack of standardization of + floating point exception handling in C, most floating point operations also + aren't checked. For plain integers, all operations that can overflow are + checked except left shift, where typical applications prefer to drop bits than + raise an exception. + + .. % XXXJH reference to long's and/or int's? + + +.. exception:: ReferenceError + + This exception is raised when a weak reference proxy, created by the + :func:`weakref.proxy` function, is used to access an attribute of the referent + after it has been garbage collected. For more information on weak references, + see the :mod:`weakref` module. + + .. versionadded:: 2.2 + Previously known as the :exc:`weakref.ReferenceError` exception. + + +.. exception:: RuntimeError + + Raised when an error is detected that doesn't fall in any of the other + categories. The associated value is a string indicating what precisely went + wrong. (This exception is mostly a relic from a previous version of the + interpreter; it is not used very much any more.) + + +.. exception:: StopIteration + + Raised by builtin :func:`next` and an iterator's :meth:`__next__` method to + signal that there are no further values. + + .. versionadded:: 2.2 + + .. versionchanged:: 3.0 + Changed to inherit from Exception instead of StandardError. + + +.. exception:: SyntaxError + + Raised when the parser encounters a syntax error. This may occur in an + :keyword:`import` statement, in a call to the built-in functions :func:`exec` + or :func:`eval`, or when reading the initial script or standard input + (also interactively). + + .. % XXXJH xref to these functions? + + Instances of this class have attributes :attr:`filename`, :attr:`lineno`, + :attr:`offset` and :attr:`text` for easier access to the details. :func:`str` + of the exception instance returns only the message. + + +.. exception:: SystemError + + Raised when the interpreter finds an internal error, but the situation does not + look so serious to cause it to abandon all hope. The associated value is a + string indicating what went wrong (in low-level terms). + + You should report this to the author or maintainer of your Python interpreter. + Be sure to report the version of the Python interpreter (``sys.version``; it is + also printed at the start of an interactive Python session), the exact error + message (the exception's associated value) and if possible the source of the + program that triggered the error. + + +.. exception:: SystemExit + + This exception is raised by the :func:`sys.exit` function. When it is not + handled, the Python interpreter exits; no stack traceback is printed. If the + associated value is a plain integer, it specifies the system exit status (passed + to C's :cfunc:`exit` function); if it is ``None``, the exit status is zero; if + it has another type (such as a string), the object's value is printed and the + exit status is one. + + .. % XXX(hylton) xref to module sys? + + Instances have an attribute :attr:`code` which is set to the proposed exit + status or error message (defaulting to ``None``). Also, this exception derives + directly from :exc:`BaseException` and not :exc:`Exception`, since it is not + technically an error. + + A call to :func:`sys.exit` is translated into an exception so that clean-up + handlers (:keyword:`finally` clauses of :keyword:`try` statements) can be + executed, and so that a debugger can execute a script without running the risk + of losing control. The :func:`os._exit` function can be used if it is + absolutely positively necessary to exit immediately (for example, in the child + process after a call to :func:`fork`). + + The exception inherits from :exc:`BaseException` instead of :exc:`Exception` so + that it is not accidentally caught by code that catches :exc:`Exception`. This + allows the exception to properly propagate up and cause the interpreter to exit. + + .. versionchanged:: 2.5 + Changed to inherit from :exc:`BaseException`. + + +.. exception:: TypeError + + Raised when an operation or function is applied to an object of inappropriate + type. The associated value is a string giving details about the type mismatch. + + +.. exception:: UnboundLocalError + + Raised when a reference is made to a local variable in a function or method, but + no value has been bound to that variable. This is a subclass of + :exc:`NameError`. + + .. versionadded:: 2.0 + + +.. exception:: UnicodeError + + Raised when a Unicode-related encoding or decoding error occurs. It is a + subclass of :exc:`ValueError`. + + .. versionadded:: 2.0 + + +.. exception:: UnicodeEncodeError + + Raised when a Unicode-related error occurs during encoding. It is a subclass of + :exc:`UnicodeError`. + + .. versionadded:: 2.3 + + +.. exception:: UnicodeDecodeError + + Raised when a Unicode-related error occurs during decoding. It is a subclass of + :exc:`UnicodeError`. + + .. versionadded:: 2.3 + + +.. exception:: UnicodeTranslateError + + Raised when a Unicode-related error occurs during translating. It is a subclass + of :exc:`UnicodeError`. + + .. versionadded:: 2.3 + + +.. exception:: ValueError + + Raised when a built-in operation or function receives an argument that has the + right type but an inappropriate value, and the situation is not described by a + more precise exception such as :exc:`IndexError`. + + +.. exception:: WindowsError + + Raised when a Windows-specific error occurs or when the error number does not + correspond to an :cdata:`errno` value. The :attr:`winerror` and + :attr:`strerror` values are created from the return values of the + :cfunc:`GetLastError` and :cfunc:`FormatMessage` functions from the Windows + Platform API. The :attr:`errno` value maps the :attr:`winerror` value to + corresponding ``errno.h`` values. This is a subclass of :exc:`OSError`. + + .. versionadded:: 2.0 + + .. versionchanged:: 2.5 + Previous versions put the :cfunc:`GetLastError` codes into :attr:`errno`. + + +.. exception:: ZeroDivisionError + + Raised when the second argument of a division or modulo operation is zero. The + associated value is a string indicating the type of the operands and the + operation. + +The following exceptions are used as warning categories; see the :mod:`warnings` +module for more information. + + +.. exception:: Warning + + Base class for warning categories. + + +.. exception:: UserWarning + + Base class for warnings generated by user code. + + +.. exception:: DeprecationWarning + + Base class for warnings about deprecated features. + + +.. exception:: PendingDeprecationWarning + + Base class for warnings about features which will be deprecated in the future. + + +.. exception:: SyntaxWarning + + Base class for warnings about dubious syntax + + +.. exception:: RuntimeWarning + + Base class for warnings about dubious runtime behavior. + + +.. exception:: FutureWarning + + Base class for warnings about constructs that will change semantically in the + future. + + +.. exception:: ImportWarning + + Base class for warnings about probable mistakes in module imports. + + .. versionadded:: 2.5 + + +.. exception:: UnicodeWarning + + Base class for warnings related to Unicode. + + .. versionadded:: 2.5 + +The class hierarchy for built-in exceptions is: + + +.. literalinclude:: ../../Lib/test/exception_hierarchy.txt diff --git a/Doc/library/fcntl.rst b/Doc/library/fcntl.rst new file mode 100644 index 0000000..2d7bb9c --- /dev/null +++ b/Doc/library/fcntl.rst @@ -0,0 +1,155 @@ + +:mod:`fcntl` --- The :func:`fcntl` and :func:`ioctl` system calls +================================================================= + +.. module:: fcntl + :platform: Unix + :synopsis: The fcntl() and ioctl() system calls. +.. sectionauthor:: Jaap Vermeulen + + +.. index:: + pair: UNIX@Unix; file control + pair: UNIX@Unix; I/O control + +This module performs file control and I/O control on file descriptors. It is an +interface to the :cfunc:`fcntl` and :cfunc:`ioctl` Unix routines. + +All functions in this module take a file descriptor *fd* as their first +argument. This can be an integer file descriptor, such as returned by +``sys.stdin.fileno()``, or a file object, such as ``sys.stdin`` itself, which +provides a :meth:`fileno` which returns a genuine file descriptor. + +The module defines the following functions: + + +.. function:: fcntl(fd, op[, arg]) + + Perform the requested operation on file descriptor *fd* (file objects providing + a :meth:`fileno` method are accepted as well). The operation is defined by *op* + and is operating system dependent. These codes are also found in the + :mod:`fcntl` module. The argument *arg* is optional, and defaults to the integer + value ``0``. When present, it can either be an integer value, or a string. + With the argument missing or an integer value, the return value of this function + is the integer return value of the C :cfunc:`fcntl` call. When the argument is + a string it represents a binary structure, e.g. created by :func:`struct.pack`. + The binary data is copied to a buffer whose address is passed to the C + :cfunc:`fcntl` call. The return value after a successful call is the contents + of the buffer, converted to a string object. The length of the returned string + will be the same as the length of the *arg* argument. This is limited to 1024 + bytes. If the information returned in the buffer by the operating system is + larger than 1024 bytes, this is most likely to result in a segmentation + violation or a more subtle data corruption. + + If the :cfunc:`fcntl` fails, an :exc:`IOError` is raised. + + +.. function:: ioctl(fd, op[, arg[, mutate_flag]]) + + This function is identical to the :func:`fcntl` function, except that the + operations are typically defined in the library module :mod:`termios` and the + argument handling is even more complicated. + + The parameter *arg* can be one of an integer, absent (treated identically to the + integer ``0``), an object supporting the read-only buffer interface (most likely + a plain Python string) or an object supporting the read-write buffer interface. + + In all but the last case, behaviour is as for the :func:`fcntl` function. + + If a mutable buffer is passed, then the behaviour is determined by the value of + the *mutate_flag* parameter. + + If it is false, the buffer's mutability is ignored and behaviour is as for a + read-only buffer, except that the 1024 byte limit mentioned above is avoided -- + so long as the buffer you pass is as least as long as what the operating system + wants to put there, things should work. + + If *mutate_flag* is true, then the buffer is (in effect) passed to the + underlying :func:`ioctl` system call, the latter's return code is passed back to + the calling Python, and the buffer's new contents reflect the action of the + :func:`ioctl`. This is a slight simplification, because if the supplied buffer + is less than 1024 bytes long it is first copied into a static buffer 1024 bytes + long which is then passed to :func:`ioctl` and copied back into the supplied + buffer. + + If *mutate_flag* is not supplied, then from Python 2.5 it defaults to true, + which is a change from versions 2.3 and 2.4. Supply the argument explicitly if + version portability is a priority. + + An example:: + + >>> import array, fcntl, struct, termios, os + >>> os.getpgrp() + 13341 + >>> struct.unpack('h', fcntl.ioctl(0, termios.TIOCGPGRP, " "))[0] + 13341 + >>> buf = array.array('h', [0]) + >>> fcntl.ioctl(0, termios.TIOCGPGRP, buf, 1) + 0 + >>> buf + array('h', [13341]) + + +.. function:: flock(fd, op) + + Perform the lock operation *op* on file descriptor *fd* (file objects providing + a :meth:`fileno` method are accepted as well). See the Unix manual + :manpage:`flock(3)` for details. (On some systems, this function is emulated + using :cfunc:`fcntl`.) + + +.. function:: lockf(fd, operation, [length, [start, [whence]]]) + + This is essentially a wrapper around the :func:`fcntl` locking calls. *fd* is + the file descriptor of the file to lock or unlock, and *operation* is one of the + following values: + + * :const:`LOCK_UN` -- unlock + * :const:`LOCK_SH` -- acquire a shared lock + * :const:`LOCK_EX` -- acquire an exclusive lock + + When *operation* is :const:`LOCK_SH` or :const:`LOCK_EX`, it can also be + bit-wise OR'd with :const:`LOCK_NB` to avoid blocking on lock acquisition. + If :const:`LOCK_NB` is used and the lock cannot be acquired, an + :exc:`IOError` will be raised and the exception will have an *errno* + attribute set to :const:`EACCES` or :const:`EAGAIN` (depending on the + operating system; for portability, check for both values). On at least some + systems, :const:`LOCK_EX` can only be used if the file descriptor refers to a + file opened for writing. + + *length* is the number of bytes to lock, *start* is the byte offset at which the + lock starts, relative to *whence*, and *whence* is as with :func:`fileobj.seek`, + specifically: + + * :const:`0` -- relative to the start of the file (:const:`SEEK_SET`) + * :const:`1` -- relative to the current buffer position (:const:`SEEK_CUR`) + * :const:`2` -- relative to the end of the file (:const:`SEEK_END`) + + The default for *start* is 0, which means to start at the beginning of the file. + The default for *length* is 0 which means to lock to the end of the file. The + default for *whence* is also 0. + +Examples (all on a SVR4 compliant system):: + + import struct, fcntl, os + + f = open(...) + rv = fcntl.fcntl(f, fcntl.F_SETFL, os.O_NDELAY) + + lockdata = struct.pack('hhllhh', fcntl.F_WRLCK, 0, 0, 0, 0, 0) + rv = fcntl.fcntl(f, fcntl.F_SETLKW, lockdata) + +Note that in the first example the return value variable *rv* will hold an +integer value; in the second example it will hold a string value. The structure +lay-out for the *lockdata* variable is system dependent --- therefore using the +:func:`flock` call may be better. + + +.. seealso:: + + Module :mod:`os` + If the locking flags :const:`O_SHLOCK` and :const:`O_EXLOCK` are present + in the :mod:`os` module, the :func:`os.open` function provides a more + platform-independent alternative to the :func:`lockf` and :func:`flock` + functions. + diff --git a/Doc/library/filecmp.rst b/Doc/library/filecmp.rst new file mode 100644 index 0000000..6004214 --- /dev/null +++ b/Doc/library/filecmp.rst @@ -0,0 +1,152 @@ + +:mod:`filecmp` --- File and Directory Comparisons +================================================= + +.. module:: filecmp + :synopsis: Compare files efficiently. +.. sectionauthor:: Moshe Zadka + + +The :mod:`filecmp` module defines functions to compare files and directories, +with various optional time/correctness trade-offs. + +The :mod:`filecmp` module defines the following functions: + + +.. function:: cmp(f1, f2[, shallow]) + + Compare the files named *f1* and *f2*, returning ``True`` if they seem equal, + ``False`` otherwise. + + Unless *shallow* is given and is false, files with identical :func:`os.stat` + signatures are taken to be equal. + + Files that were compared using this function will not be compared again unless + their :func:`os.stat` signature changes. + + Note that no external programs are called from this function, giving it + portability and efficiency. + + +.. function:: cmpfiles(dir1, dir2, common[, shallow]) + + Returns three lists of file names: *match*, *mismatch*, *errors*. *match* + contains the list of files match in both directories, *mismatch* includes the + names of those that don't, and *errros* lists the names of files which could not + be compared. Files may be listed in *errors* because the user may lack + permission to read them or many other reasons, but always that the comparison + could not be done for some reason. + + The *common* parameter is a list of file names found in both directories. The + *shallow* parameter has the same meaning and default value as for + :func:`filecmp.cmp`. + +Example:: + + >>> import filecmp + >>> filecmp.cmp('undoc.rst', 'undoc.rst') + True + >>> filecmp.cmp('undoc.rst', 'index.rst') + False + + +.. _dircmp-objects: + +The :class:`dircmp` class +------------------------- + +:class:`dircmp` instances are built using this constructor: + + +.. class:: dircmp(a, b[, ignore[, hide]]) + + Construct a new directory comparison object, to compare the directories *a* and + *b*. *ignore* is a list of names to ignore, and defaults to ``['RCS', 'CVS', + 'tags']``. *hide* is a list of names to hide, and defaults to ``[os.curdir, + os.pardir]``. + +The :class:`dircmp` class provides the following methods: + + +.. method:: dircmp.report() + + Print (to ``sys.stdout``) a comparison between *a* and *b*. + + +.. method:: dircmp.report_partial_closure() + + Print a comparison between *a* and *b* and common immediate subdirectories. + + +.. method:: dircmp.report_full_closure() + + Print a comparison between *a* and *b* and common subdirectories (recursively). + +The :class:`dircmp` offers a number of interesting attributes that may be used +to get various bits of information about the directory trees being compared. + +Note that via :meth:`__getattr__` hooks, all attributes are computed lazily, so +there is no speed penalty if only those attributes which are lightweight to +compute are used. + + +.. attribute:: dircmp.left_list + + Files and subdirectories in *a*, filtered by *hide* and *ignore*. + + +.. attribute:: dircmp.right_list + + Files and subdirectories in *b*, filtered by *hide* and *ignore*. + + +.. attribute:: dircmp.common + + Files and subdirectories in both *a* and *b*. + + +.. attribute:: dircmp.left_only + + Files and subdirectories only in *a*. + + +.. attribute:: dircmp.right_only + + Files and subdirectories only in *b*. + + +.. attribute:: dircmp.common_dirs + + Subdirectories in both *a* and *b*. + + +.. attribute:: dircmp.common_files + + Files in both *a* and *b* + + +.. attribute:: dircmp.common_funny + + Names in both *a* and *b*, such that the type differs between the directories, + or names for which :func:`os.stat` reports an error. + + +.. attribute:: dircmp.same_files + + Files which are identical in both *a* and *b*. + + +.. attribute:: dircmp.diff_files + + Files which are in both *a* and *b*, whose contents differ. + + +.. attribute:: dircmp.funny_files + + Files which are in both *a* and *b*, but could not be compared. + + +.. attribute:: dircmp.subdirs + + A dictionary mapping names in :attr:`common_dirs` to :class:`dircmp` objects. + diff --git a/Doc/library/fileformats.rst b/Doc/library/fileformats.rst new file mode 100644 index 0000000..c0c2eed --- /dev/null +++ b/Doc/library/fileformats.rst @@ -0,0 +1,18 @@ + +.. _fileformats: + +************ +File Formats +************ + +The modules described in this chapter parse various miscellaneous file formats +that aren't markup languages or are related to e-mail. + + +.. toctree:: + + csv.rst + configparser.rst + robotparser.rst + netrc.rst + xdrlib.rst diff --git a/Doc/library/fileinput.rst b/Doc/library/fileinput.rst new file mode 100644 index 0000000..d0a3ed9 --- /dev/null +++ b/Doc/library/fileinput.rst @@ -0,0 +1,183 @@ +:mod:`fileinput` --- Iterate over lines from multiple input streams +=================================================================== + +.. module:: fileinput + :synopsis: Loop over standard input or a list of files. +.. moduleauthor:: Guido van Rossum +.. sectionauthor:: Fred L. Drake, Jr. + + +This module implements a helper class and functions to quickly write a loop over +standard input or a list of files. + +The typical use is:: + + import fileinput + for line in fileinput.input(): + process(line) + +This iterates over the lines of all files listed in ``sys.argv[1:]``, defaulting +to ``sys.stdin`` if the list is empty. If a filename is ``'-'``, it is also +replaced by ``sys.stdin``. To specify an alternative list of filenames, pass it +as the first argument to :func:`input`. A single file name is also allowed. + +All files are opened in text mode by default, but you can override this by +specifying the *mode* parameter in the call to :func:`input` or +:class:`FileInput()`. If an I/O error occurs during opening or reading a file, +:exc:`IOError` is raised. + +If ``sys.stdin`` is used more than once, the second and further use will return +no lines, except perhaps for interactive use, or if it has been explicitly reset +(e.g. using ``sys.stdin.seek(0)``). + +Empty files are opened and immediately closed; the only time their presence in +the list of filenames is noticeable at all is when the last file opened is +empty. + +Lines are returned with any newlines intact, which means that the last line in +a file may not have one. + +You can control how files are opened by providing an opening hook via the +*openhook* parameter to :func:`fileinput.input` or :class:`FileInput()`. The +hook must be a function that takes two arguments, *filename* and *mode*, and +returns an accordingly opened file-like object. Two useful hooks are already +provided by this module. + +The following function is the primary interface of this module: + + +.. function:: input([files[, inplace[, backup[, mode[, openhook]]]]]) + + Create an instance of the :class:`FileInput` class. The instance will be used + as global state for the functions of this module, and is also returned to use + during iteration. The parameters to this function will be passed along to the + constructor of the :class:`FileInput` class. + + .. versionchanged:: 2.5 + Added the *mode* and *openhook* parameters. + +The following functions use the global state created by :func:`fileinput.input`; +if there is no active state, :exc:`RuntimeError` is raised. + + +.. function:: filename() + + Return the name of the file currently being read. Before the first line has + been read, returns ``None``. + + +.. function:: fileno() + + Return the integer "file descriptor" for the current file. When no file is + opened (before the first line and between files), returns ``-1``. + + .. versionadded:: 2.5 + + +.. function:: lineno() + + Return the cumulative line number of the line that has just been read. Before + the first line has been read, returns ``0``. After the last line of the last + file has been read, returns the line number of that line. + + +.. function:: filelineno() + + Return the line number in the current file. Before the first line has been + read, returns ``0``. After the last line of the last file has been read, + returns the line number of that line within the file. + + +.. function:: isfirstline() + + Returns true if the line just read is the first line of its file, otherwise + returns false. + + +.. function:: isstdin() + + Returns true if the last line was read from ``sys.stdin``, otherwise returns + false. + + +.. function:: nextfile() + + Close the current file so that the next iteration will read the first line from + the next file (if any); lines not read from the file will not count towards the + cumulative line count. The filename is not changed until after the first line + of the next file has been read. Before the first line has been read, this + function has no effect; it cannot be used to skip the first file. After the + last line of the last file has been read, this function has no effect. + + +.. function:: close() + + Close the sequence. + +The class which implements the sequence behavior provided by the module is +available for subclassing as well: + + +.. class:: FileInput([files[, inplace[, backup[, mode[, openhook]]]]]) + + Class :class:`FileInput` is the implementation; its methods :meth:`filename`, + :meth:`fileno`, :meth:`lineno`, :meth:`filelineno`, :meth:`isfirstline`, + :meth:`isstdin`, :meth:`nextfile` and :meth:`close` correspond to the functions + of the same name in the module. In addition it has a :meth:`readline` method + which returns the next input line, and a :meth:`__getitem__` method which + implements the sequence behavior. The sequence must be accessed in strictly + sequential order; random access and :meth:`readline` cannot be mixed. + + With *mode* you can specify which file mode will be passed to :func:`open`. It + must be one of ``'r'``, ``'rU'``, ``'U'`` and ``'rb'``. + + The *openhook*, when given, must be a function that takes two arguments, + *filename* and *mode*, and returns an accordingly opened file-like object. You + cannot use *inplace* and *openhook* together. + + .. versionchanged:: 2.5 + Added the *mode* and *openhook* parameters. + +**Optional in-place filtering:** if the keyword argument ``inplace=1`` is passed +to :func:`fileinput.input` or to the :class:`FileInput` constructor, the file is +moved to a backup file and standard output is directed to the input file (if a +file of the same name as the backup file already exists, it will be replaced +silently). This makes it possible to write a filter that rewrites its input +file in place. If the *backup* parameter is given (typically as +``backup='.'``), it specifies the extension for the backup file, +and the backup file remains around; by default, the extension is ``'.bak'`` and +it is deleted when the output file is closed. In-place filtering is disabled +when standard input is read. + +**Caveat:** The current implementation does not work for MS-DOS 8+3 filesystems. + +The two following opening hooks are provided by this module: + + +.. function:: hook_compressed(filename, mode) + + Transparently opens files compressed with gzip and bzip2 (recognized by the + extensions ``'.gz'`` and ``'.bz2'``) using the :mod:`gzip` and :mod:`bz2` + modules. If the filename extension is not ``'.gz'`` or ``'.bz2'``, the file is + opened normally (ie, using :func:`open` without any decompression). + + Usage example: ``fi = fileinput.FileInput(openhook=fileinput.hook_compressed)`` + + .. versionadded:: 2.5 + + +.. function:: hook_encoded(encoding) + + Returns a hook which opens each file with :func:`codecs.open`, using the given + *encoding* to read the file. + + Usage example: ``fi = + fileinput.FileInput(openhook=fileinput.hook_encoded("iso-8859-1"))`` + + .. note:: + + With this hook, :class:`FileInput` might return Unicode strings depending on the + specified *encoding*. + + .. versionadded:: 2.5 + diff --git a/Doc/library/filesys.rst b/Doc/library/filesys.rst new file mode 100644 index 0000000..e5b5e44 --- /dev/null +++ b/Doc/library/filesys.rst @@ -0,0 +1,38 @@ + +.. _filesys: + +************************* +File and Directory Access +************************* + +The modules described in this chapter deal with disk files and directories. For +example, there are modules for reading the properties of files, manipulating +paths in a portable way, and creating temporary files. The full list of modules +in this chapter is: + + +.. toctree:: + + os.path.rst + fileinput.rst + stat.rst + statvfs.rst + filecmp.rst + tempfile.rst + glob.rst + fnmatch.rst + linecache.rst + shutil.rst + dircache.rst + macpath.rst + + +.. seealso:: + + Section :ref:`bltin-file-objects` + A description of Python's built-in file objects. + + Module :mod:`os` + Operating system interfaces, including functions to work with files at a lower + level than the built-in file object. + diff --git a/Doc/library/fnmatch.rst b/Doc/library/fnmatch.rst new file mode 100644 index 0000000..244bad9 --- /dev/null +++ b/Doc/library/fnmatch.rst @@ -0,0 +1,91 @@ + +:mod:`fnmatch` --- Unix filename pattern matching +================================================= + +.. module:: fnmatch + :synopsis: Unix shell style filename pattern matching. + + +.. index:: single: filenames; wildcard expansion + +.. index:: module: re + +This module provides support for Unix shell-style wildcards, which are *not* the +same as regular expressions (which are documented in the :mod:`re` module). The +special characters used in shell-style wildcards are: + ++------------+------------------------------------+ +| Pattern | Meaning | ++============+====================================+ +| ``*`` | matches everything | ++------------+------------------------------------+ +| ``?`` | matches any single character | ++------------+------------------------------------+ +| ``[seq]`` | matches any character in *seq* | ++------------+------------------------------------+ +| ``[!seq]`` | matches any character not in *seq* | ++------------+------------------------------------+ + +.. index:: module: glob + +Note that the filename separator (``'/'`` on Unix) is *not* special to this +module. See module :mod:`glob` for pathname expansion (:mod:`glob` uses +:func:`fnmatch` to match pathname segments). Similarly, filenames starting with +a period are not special for this module, and are matched by the ``*`` and ``?`` +patterns. + + +.. function:: fnmatch(filename, pattern) + + Test whether the *filename* string matches the *pattern* string, returning true + or false. If the operating system is case-insensitive, then both parameters + will be normalized to all lower- or upper-case before the comparison is + performed. If you require a case-sensitive comparison regardless of whether + that's standard for your operating system, use :func:`fnmatchcase` instead. + + This example will print all file names in the current directory with the + extension ``.txt``:: + + import fnmatch + import os + + for file in os.listdir('.'): + if fnmatch.fnmatch(file, '*.txt'): + print file + + +.. function:: fnmatchcase(filename, pattern) + + Test whether *filename* matches *pattern*, returning true or false; the + comparison is case-sensitive. + + +.. function:: filter(names, pattern) + + Return the subset of the list of *names* that match *pattern*. It is the same as + ``[n for n in names if fnmatch(n, pattern)]``, but implemented more efficiently. + + .. versionadded:: 2.2 + + +.. function:: translate(pattern) + + Return the shell-style *pattern* converted to a regular expression. + + Example:: + + >>> import fnmatch, re + >>> + >>> regex = fnmatch.translate('*.txt') + >>> regex + '.*\\.txt$' + >>> reobj = re.compile(regex) + >>> print reobj.match('foobar.txt') + <_sre.SRE_Match object at 0x...> + + +.. seealso:: + + Module :mod:`glob` + Unix shell-style path expansion. + diff --git a/Doc/library/formatter.rst b/Doc/library/formatter.rst new file mode 100644 index 0000000..2774a2b --- /dev/null +++ b/Doc/library/formatter.rst @@ -0,0 +1,350 @@ + +:mod:`formatter` --- Generic output formatting +============================================== + +.. module:: formatter + :synopsis: Generic output formatter and device interface. + + +.. index:: single: HTMLParser (class in htmllib) + +This module supports two interface definitions, each with multiple +implementations. The *formatter* interface is used by the :class:`HTMLParser` +class of the :mod:`htmllib` module, and the *writer* interface is required by +the formatter interface. + +Formatter objects transform an abstract flow of formatting events into specific +output events on writer objects. Formatters manage several stack structures to +allow various properties of a writer object to be changed and restored; writers +need not be able to handle relative changes nor any sort of "change back" +operation. Specific writer properties which may be controlled via formatter +objects are horizontal alignment, font, and left margin indentations. A +mechanism is provided which supports providing arbitrary, non-exclusive style +settings to a writer as well. Additional interfaces facilitate formatting +events which are not reversible, such as paragraph separation. + +Writer objects encapsulate device interfaces. Abstract devices, such as file +formats, are supported as well as physical devices. The provided +implementations all work with abstract devices. The interface makes available +mechanisms for setting the properties which formatter objects manage and +inserting data into the output. + + +.. _formatter-interface: + +The Formatter Interface +----------------------- + +Interfaces to create formatters are dependent on the specific formatter class +being instantiated. The interfaces described below are the required interfaces +which all formatters must support once initialized. + +One data element is defined at the module level: + + +.. data:: AS_IS + + Value which can be used in the font specification passed to the ``push_font()`` + method described below, or as the new value to any other ``push_property()`` + method. Pushing the ``AS_IS`` value allows the corresponding ``pop_property()`` + method to be called without having to track whether the property was changed. + +The following attributes are defined for formatter instance objects: + + +.. attribute:: formatter.writer + + The writer instance with which the formatter interacts. + + +.. method:: formatter.end_paragraph(blanklines) + + Close any open paragraphs and insert at least *blanklines* before the next + paragraph. + + +.. method:: formatter.add_line_break() + + Add a hard line break if one does not already exist. This does not break the + logical paragraph. + + +.. method:: formatter.add_hor_rule(*args, **kw) + + Insert a horizontal rule in the output. A hard break is inserted if there is + data in the current paragraph, but the logical paragraph is not broken. The + arguments and keywords are passed on to the writer's :meth:`send_line_break` + method. + + +.. method:: formatter.add_flowing_data(data) + + Provide data which should be formatted with collapsed whitespace. Whitespace + from preceding and successive calls to :meth:`add_flowing_data` is considered as + well when the whitespace collapse is performed. The data which is passed to + this method is expected to be word-wrapped by the output device. Note that any + word-wrapping still must be performed by the writer object due to the need to + rely on device and font information. + + +.. method:: formatter.add_literal_data(data) + + Provide data which should be passed to the writer unchanged. Whitespace, + including newline and tab characters, are considered legal in the value of + *data*. + + +.. method:: formatter.add_label_data(format, counter) + + Insert a label which should be placed to the left of the current left margin. + This should be used for constructing bulleted or numbered lists. If the + *format* value is a string, it is interpreted as a format specification for + *counter*, which should be an integer. The result of this formatting becomes the + value of the label; if *format* is not a string it is used as the label value + directly. The label value is passed as the only argument to the writer's + :meth:`send_label_data` method. Interpretation of non-string label values is + dependent on the associated writer. + + Format specifications are strings which, in combination with a counter value, + are used to compute label values. Each character in the format string is copied + to the label value, with some characters recognized to indicate a transform on + the counter value. Specifically, the character ``'1'`` represents the counter + value formatter as an Arabic number, the characters ``'A'`` and ``'a'`` + represent alphabetic representations of the counter value in upper and lower + case, respectively, and ``'I'`` and ``'i'`` represent the counter value in Roman + numerals, in upper and lower case. Note that the alphabetic and roman + transforms require that the counter value be greater than zero. + + +.. method:: formatter.flush_softspace() + + Send any pending whitespace buffered from a previous call to + :meth:`add_flowing_data` to the associated writer object. This should be called + before any direct manipulation of the writer object. + + +.. method:: formatter.push_alignment(align) + + Push a new alignment setting onto the alignment stack. This may be + :const:`AS_IS` if no change is desired. If the alignment value is changed from + the previous setting, the writer's :meth:`new_alignment` method is called with + the *align* value. + + +.. method:: formatter.pop_alignment() + + Restore the previous alignment. + + +.. method:: formatter.push_font((size, italic, bold, teletype)) + + Change some or all font properties of the writer object. Properties which are + not set to :const:`AS_IS` are set to the values passed in while others are + maintained at their current settings. The writer's :meth:`new_font` method is + called with the fully resolved font specification. + + +.. method:: formatter.pop_font() + + Restore the previous font. + + +.. method:: formatter.push_margin(margin) + + Increase the number of left margin indentations by one, associating the logical + tag *margin* with the new indentation. The initial margin level is ``0``. + Changed values of the logical tag must be true values; false values other than + :const:`AS_IS` are not sufficient to change the margin. + + +.. method:: formatter.pop_margin() + + Restore the previous margin. + + +.. method:: formatter.push_style(*styles) + + Push any number of arbitrary style specifications. All styles are pushed onto + the styles stack in order. A tuple representing the entire stack, including + :const:`AS_IS` values, is passed to the writer's :meth:`new_styles` method. + + +.. method:: formatter.pop_style([n=1]) + + Pop the last *n* style specifications passed to :meth:`push_style`. A tuple + representing the revised stack, including :const:`AS_IS` values, is passed to + the writer's :meth:`new_styles` method. + + +.. method:: formatter.set_spacing(spacing) + + Set the spacing style for the writer. + + +.. method:: formatter.assert_line_data([flag=1]) + + Inform the formatter that data has been added to the current paragraph + out-of-band. This should be used when the writer has been manipulated + directly. The optional *flag* argument can be set to false if the writer + manipulations produced a hard line break at the end of the output. + + +.. _formatter-impls: + +Formatter Implementations +------------------------- + +Two implementations of formatter objects are provided by this module. Most +applications may use one of these classes without modification or subclassing. + + +.. class:: NullFormatter([writer]) + + A formatter which does nothing. If *writer* is omitted, a :class:`NullWriter` + instance is created. No methods of the writer are called by + :class:`NullFormatter` instances. Implementations should inherit from this + class if implementing a writer interface but don't need to inherit any + implementation. + + +.. class:: AbstractFormatter(writer) + + The standard formatter. This implementation has demonstrated wide applicability + to many writers, and may be used directly in most circumstances. It has been + used to implement a full-featured World Wide Web browser. + + +.. _writer-interface: + +The Writer Interface +-------------------- + +Interfaces to create writers are dependent on the specific writer class being +instantiated. The interfaces described below are the required interfaces which +all writers must support once initialized. Note that while most applications can +use the :class:`AbstractFormatter` class as a formatter, the writer must +typically be provided by the application. + + +.. method:: writer.flush() + + Flush any buffered output or device control events. + + +.. method:: writer.new_alignment(align) + + Set the alignment style. The *align* value can be any object, but by convention + is a string or ``None``, where ``None`` indicates that the writer's "preferred" + alignment should be used. Conventional *align* values are ``'left'``, + ``'center'``, ``'right'``, and ``'justify'``. + + +.. method:: writer.new_font(font) + + Set the font style. The value of *font* will be ``None``, indicating that the + device's default font should be used, or a tuple of the form ``(``*size*, + *italic*, *bold*, *teletype*``)``. Size will be a string indicating the size of + font that should be used; specific strings and their interpretation must be + defined by the application. The *italic*, *bold*, and *teletype* values are + Boolean values specifying which of those font attributes should be used. + + +.. method:: writer.new_margin(margin, level) + + Set the margin level to the integer *level* and the logical tag to *margin*. + Interpretation of the logical tag is at the writer's discretion; the only + restriction on the value of the logical tag is that it not be a false value for + non-zero values of *level*. + + +.. method:: writer.new_spacing(spacing) + + Set the spacing style to *spacing*. + + +.. method:: writer.new_styles(styles) + + Set additional styles. The *styles* value is a tuple of arbitrary values; the + value :const:`AS_IS` should be ignored. The *styles* tuple may be interpreted + either as a set or as a stack depending on the requirements of the application + and writer implementation. + + +.. method:: writer.send_line_break() + + Break the current line. + + +.. method:: writer.send_paragraph(blankline) + + Produce a paragraph separation of at least *blankline* blank lines, or the + equivalent. The *blankline* value will be an integer. Note that the + implementation will receive a call to :meth:`send_line_break` before this call + if a line break is needed; this method should not include ending the last line + of the paragraph. It is only responsible for vertical spacing between + paragraphs. + + +.. method:: writer.send_hor_rule(*args, **kw) + + Display a horizontal rule on the output device. The arguments to this method + are entirely application- and writer-specific, and should be interpreted with + care. The method implementation may assume that a line break has already been + issued via :meth:`send_line_break`. + + +.. method:: writer.send_flowing_data(data) + + Output character data which may be word-wrapped and re-flowed as needed. Within + any sequence of calls to this method, the writer may assume that spans of + multiple whitespace characters have been collapsed to single space characters. + + +.. method:: writer.send_literal_data(data) + + Output character data which has already been formatted for display. Generally, + this should be interpreted to mean that line breaks indicated by newline + characters should be preserved and no new line breaks should be introduced. The + data may contain embedded newline and tab characters, unlike data provided to + the :meth:`send_formatted_data` interface. + + +.. method:: writer.send_label_data(data) + + Set *data* to the left of the current left margin, if possible. The value of + *data* is not restricted; treatment of non-string values is entirely + application- and writer-dependent. This method will only be called at the + beginning of a line. + + +.. _writer-impls: + +Writer Implementations +---------------------- + +Three implementations of the writer object interface are provided as examples by +this module. Most applications will need to derive new writer classes from the +:class:`NullWriter` class. + + +.. class:: NullWriter() + + A writer which only provides the interface definition; no actions are taken on + any methods. This should be the base class for all writers which do not need to + inherit any implementation methods. + + +.. class:: AbstractWriter() + + A writer which can be used in debugging formatters, but not much else. Each + method simply announces itself by printing its name and arguments on standard + output. + + +.. class:: DumbWriter([file[, maxcol=72]]) + + Simple writer class which writes output on the file object passed in as *file* + or, if *file* is omitted, on standard output. The output is simply word-wrapped + to the number of columns specified by *maxcol*. This class is suitable for + reflowing a sequence of paragraphs. + diff --git a/Doc/library/fpectl.rst b/Doc/library/fpectl.rst new file mode 100644 index 0000000..ef030f0 --- /dev/null +++ b/Doc/library/fpectl.rst @@ -0,0 +1,120 @@ + +:mod:`fpectl` --- Floating point exception control +================================================== + +.. module:: fpectl + :platform: Unix + :synopsis: Provide control for floating point exception handling. +.. moduleauthor:: Lee Busby +.. sectionauthor:: Lee Busby + + +.. note:: + + The :mod:`fpectl` module is not built by default, and its usage is discouraged + and may be dangerous except in the hands of experts. See also the section + :ref:`fpectl-limitations` on limitations for more details. + +.. index:: single: IEEE-754 + +Most computers carry out floating point operations in conformance with the +so-called IEEE-754 standard. On any real computer, some floating point +operations produce results that cannot be expressed as a normal floating point +value. For example, try :: + + >>> import math + >>> math.exp(1000) + inf + >>> math.exp(1000) / math.exp(1000) + nan + +(The example above will work on many platforms. DEC Alpha may be one exception.) +"Inf" is a special, non-numeric value in IEEE-754 that stands for "infinity", +and "nan" means "not a number." Note that, other than the non-numeric results, +nothing special happened when you asked Python to carry out those calculations. +That is in fact the default behaviour prescribed in the IEEE-754 standard, and +if it works for you, stop reading now. + +In some circumstances, it would be better to raise an exception and stop +processing at the point where the faulty operation was attempted. The +:mod:`fpectl` module is for use in that situation. It provides control over +floating point units from several hardware manufacturers, allowing the user to +turn on the generation of :const:`SIGFPE` whenever any of the IEEE-754 +exceptions Division by Zero, Overflow, or Invalid Operation occurs. In tandem +with a pair of wrapper macros that are inserted into the C code comprising your +python system, :const:`SIGFPE` is trapped and converted into the Python +:exc:`FloatingPointError` exception. + +The :mod:`fpectl` module defines the following functions and may raise the given +exception: + + +.. function:: turnon_sigfpe() + + Turn on the generation of :const:`SIGFPE`, and set up an appropriate signal + handler. + + +.. function:: turnoff_sigfpe() + + Reset default handling of floating point exceptions. + + +.. exception:: FloatingPointError + + After :func:`turnon_sigfpe` has been executed, a floating point operation that + raises one of the IEEE-754 exceptions Division by Zero, Overflow, or Invalid + operation will in turn raise this standard Python exception. + + +.. _fpectl-example: + +Example +------- + +The following example demonstrates how to start up and test operation of the +:mod:`fpectl` module. :: + + >>> import fpectl + >>> import fpetest + >>> fpectl.turnon_sigfpe() + >>> fpetest.test() + overflow PASS + FloatingPointError: Overflow + + div by 0 PASS + FloatingPointError: Division by zero + [ more output from test elided ] + >>> import math + >>> math.exp(1000) + Traceback (most recent call last): + File "", line 1, in ? + FloatingPointError: in math_1 + + +.. _fpectl-limitations: + +Limitations and other considerations +------------------------------------ + +Setting up a given processor to trap IEEE-754 floating point errors currently +requires custom code on a per-architecture basis. You may have to modify +:mod:`fpectl` to control your particular hardware. + +Conversion of an IEEE-754 exception to a Python exception requires that the +wrapper macros ``PyFPE_START_PROTECT`` and ``PyFPE_END_PROTECT`` be inserted +into your code in an appropriate fashion. Python itself has been modified to +support the :mod:`fpectl` module, but many other codes of interest to numerical +analysts have not. + +The :mod:`fpectl` module is not thread-safe. + + +.. seealso:: + + Some files in the source distribution may be interesting in learning more about + how this module operates. The include file :file:`Include/pyfpe.h` discusses the + implementation of this module at some length. :file:`Modules/fpetestmodule.c` + gives several examples of use. Many additional examples can be found in + :file:`Objects/floatobject.c`. + diff --git a/Doc/library/fpformat.rst b/Doc/library/fpformat.rst new file mode 100644 index 0000000..33655fb --- /dev/null +++ b/Doc/library/fpformat.rst @@ -0,0 +1,56 @@ + +:mod:`fpformat` --- Floating point conversions +============================================== + +.. module:: fpformat + :synopsis: General floating point formatting functions. +.. sectionauthor:: Moshe Zadka + + +The :mod:`fpformat` module defines functions for dealing with floating point +numbers representations in 100% pure Python. + +.. note:: + + This module is unneeded: everything here could be done via the ``%`` string + interpolation operator. + +The :mod:`fpformat` module defines the following functions and an exception: + + +.. function:: fix(x, digs) + + Format *x* as ``[-]ddd.ddd`` with *digs* digits after the point and at least one + digit before. If ``digs <= 0``, the decimal point is suppressed. + + *x* can be either a number or a string that looks like one. *digs* is an + integer. + + Return value is a string. + + +.. function:: sci(x, digs) + + Format *x* as ``[-]d.dddE[+-]ddd`` with *digs* digits after the point and + exactly one digit before. If ``digs <= 0``, one digit is kept and the point is + suppressed. + + *x* can be either a real number, or a string that looks like one. *digs* is an + integer. + + Return value is a string. + + +.. exception:: NotANumber + + Exception raised when a string passed to :func:`fix` or :func:`sci` as the *x* + parameter does not look like a number. This is a subclass of :exc:`ValueError` + when the standard exceptions are strings. The exception value is the improperly + formatted string that caused the exception to be raised. + +Example:: + + >>> import fpformat + >>> fpformat.fix(1.23, 1) + '1.2' + diff --git a/Doc/library/framework.rst b/Doc/library/framework.rst new file mode 100644 index 0000000..c665fb7 --- /dev/null +++ b/Doc/library/framework.rst @@ -0,0 +1,335 @@ + +:mod:`FrameWork` --- Interactive application framework +====================================================== + +.. module:: FrameWork + :platform: Mac + :synopsis: Interactive application framework. + + +The :mod:`FrameWork` module contains classes that together provide a framework +for an interactive Macintosh application. The programmer builds an application +by creating subclasses that override various methods of the bases classes, +thereby implementing the functionality wanted. Overriding functionality can +often be done on various different levels, i.e. to handle clicks in a single +dialog window in a non-standard way it is not necessary to override the complete +event handling. + +Work on the :mod:`FrameWork` has pretty much stopped, now that :mod:`PyObjC` is +available for full Cocoa access from Python, and the documentation describes +only the most important functionality, and not in the most logical manner at +that. Examine the source or the examples for more details. The following are +some comments posted on the MacPython newsgroup about the strengths and +limitations of :mod:`FrameWork`: + + +.. epigraph:: + + The strong point of :mod:`FrameWork` is that it allows you to break into the + control-flow at many different places. :mod:`W`, for instance, uses a different + way to enable/disable menus and that plugs right in leaving the rest intact. + The weak points of :mod:`FrameWork` are that it has no abstract command + interface (but that shouldn't be difficult), that its dialog support is minimal + and that its control/toolbar support is non-existent. + +The :mod:`FrameWork` module defines the following functions: + + +.. function:: Application() + + An object representing the complete application. See below for a description of + the methods. The default :meth:`__init__` routine creates an empty window + dictionary and a menu bar with an apple menu. + + +.. function:: MenuBar() + + An object representing the menubar. This object is usually not created by the + user. + + +.. function:: Menu(bar, title[, after]) + + An object representing a menu. Upon creation you pass the ``MenuBar`` the menu + appears in, the *title* string and a position (1-based) *after* where the menu + should appear (default: at the end). + + +.. function:: MenuItem(menu, title[, shortcut, callback]) + + Create a menu item object. The arguments are the menu to create, the item title + string and optionally the keyboard shortcut and a callback routine. The callback + is called with the arguments menu-id, item number within menu (1-based), current + front window and the event record. + + Instead of a callable object the callback can also be a string. In this case + menu selection causes the lookup of a method in the topmost window and the + application. The method name is the callback string with ``'domenu_'`` + prepended. + + Calling the ``MenuBar`` :meth:`fixmenudimstate` method sets the correct dimming + for all menu items based on the current front window. + + +.. function:: Separator(menu) + + Add a separator to the end of a menu. + + +.. function:: SubMenu(menu, label) + + Create a submenu named *label* under menu *menu*. The menu object is returned. + + +.. function:: Window(parent) + + Creates a (modeless) window. *Parent* is the application object to which the + window belongs. The window is not displayed until later. + + +.. function:: DialogWindow(parent) + + Creates a modeless dialog window. + + +.. function:: windowbounds(width, height) + + Return a ``(left, top, right, bottom)`` tuple suitable for creation of a window + of given width and height. The window will be staggered with respect to previous + windows, and an attempt is made to keep the whole window on-screen. However, the + window will however always be the exact size given, so parts may be offscreen. + + +.. function:: setwatchcursor() + + Set the mouse cursor to a watch. + + +.. function:: setarrowcursor() + + Set the mouse cursor to an arrow. + + +.. _application-objects: + +Application Objects +------------------- + +Application objects have the following methods, among others: + + +.. method:: Application.makeusermenus() + + Override this method if you need menus in your application. Append the menus to + the attribute :attr:`menubar`. + + +.. method:: Application.getabouttext() + + Override this method to return a text string describing your application. + Alternatively, override the :meth:`do_about` method for more elaborate "about" + messages. + + +.. method:: Application.mainloop([mask[, wait]]) + + This routine is the main event loop, call it to set your application rolling. + *Mask* is the mask of events you want to handle, *wait* is the number of ticks + you want to leave to other concurrent application (default 0, which is probably + not a good idea). While raising *self* to exit the mainloop is still supported + it is not recommended: call ``self._quit()`` instead. + + The event loop is split into many small parts, each of which can be overridden. + The default methods take care of dispatching events to windows and dialogs, + handling drags and resizes, Apple Events, events for non-FrameWork windows, etc. + + In general, all event handlers should return ``1`` if the event is fully handled + and ``0`` otherwise (because the front window was not a FrameWork window, for + instance). This is needed so that update events and such can be passed on to + other windows like the Sioux console window. Calling :func:`MacOS.HandleEvent` + is not allowed within *our_dispatch* or its callees, since this may result in an + infinite loop if the code is called through the Python inner-loop event handler. + + +.. method:: Application.asyncevents(onoff) + + Call this method with a nonzero parameter to enable asynchronous event handling. + This will tell the inner interpreter loop to call the application event handler + *async_dispatch* whenever events are available. This will cause FrameWork window + updates and the user interface to remain working during long computations, but + will slow the interpreter down and may cause surprising results in non-reentrant + code (such as FrameWork itself). By default *async_dispatch* will immediately + call *our_dispatch* but you may override this to handle only certain events + asynchronously. Events you do not handle will be passed to Sioux and such. + + The old on/off value is returned. + + +.. method:: Application._quit() + + Terminate the running :meth:`mainloop` call at the next convenient moment. + + +.. method:: Application.do_char(c, event) + + The user typed character *c*. The complete details of the event can be found in + the *event* structure. This method can also be provided in a ``Window`` object, + which overrides the application-wide handler if the window is frontmost. + + +.. method:: Application.do_dialogevent(event) + + Called early in the event loop to handle modeless dialog events. The default + method simply dispatches the event to the relevant dialog (not through the + ``DialogWindow`` object involved). Override if you need special handling of + dialog events (keyboard shortcuts, etc). + + +.. method:: Application.idle(event) + + Called by the main event loop when no events are available. The null-event is + passed (so you can look at mouse position, etc). + + +.. _window-objects: + +Window Objects +-------------- + +Window objects have the following methods, among others: + + +.. method:: Window.open() + + Override this method to open a window. Store the MacOS window-id in + :attr:`self.wid` and call the :meth:`do_postopen` method to register the window + with the parent application. + + +.. method:: Window.close() + + Override this method to do any special processing on window close. Call the + :meth:`do_postclose` method to cleanup the parent state. + + +.. method:: Window.do_postresize(width, height, macoswindowid) + + Called after the window is resized. Override if more needs to be done than + calling ``InvalRect``. + + +.. method:: Window.do_contentclick(local, modifiers, event) + + The user clicked in the content part of a window. The arguments are the + coordinates (window-relative), the key modifiers and the raw event. + + +.. method:: Window.do_update(macoswindowid, event) + + An update event for the window was received. Redraw the window. + + +.. method:: Window.do_activate(activate, event) + + The window was activated (``activate == 1``) or deactivated (``activate == 0``). + Handle things like focus highlighting, etc. + + +.. _controlswindow-object: + +ControlsWindow Object +--------------------- + +ControlsWindow objects have the following methods besides those of ``Window`` +objects: + + +.. method:: ControlsWindow.do_controlhit(window, control, pcode, event) + + Part *pcode* of control *control* was hit by the user. Tracking and such has + already been taken care of. + + +.. _scrolledwindow-object: + +ScrolledWindow Object +--------------------- + +ScrolledWindow objects are ControlsWindow objects with the following extra +methods: + + +.. method:: ScrolledWindow.scrollbars([wantx[, wanty]]) + + Create (or destroy) horizontal and vertical scrollbars. The arguments specify + which you want (default: both). The scrollbars always have minimum ``0`` and + maximum ``32767``. + + +.. method:: ScrolledWindow.getscrollbarvalues() + + You must supply this method. It should return a tuple ``(x, y)`` giving the + current position of the scrollbars (between ``0`` and ``32767``). You can return + ``None`` for either to indicate the whole document is visible in that direction. + + +.. method:: ScrolledWindow.updatescrollbars() + + Call this method when the document has changed. It will call + :meth:`getscrollbarvalues` and update the scrollbars. + + +.. method:: ScrolledWindow.scrollbar_callback(which, what, value) + + Supplied by you and called after user interaction. *which* will be ``'x'`` or + ``'y'``, *what* will be ``'-'``, ``'--'``, ``'set'``, ``'++'`` or ``'+'``. For + ``'set'``, *value* will contain the new scrollbar position. + + +.. method:: ScrolledWindow.scalebarvalues(absmin, absmax, curmin, curmax) + + Auxiliary method to help you calculate values to return from + :meth:`getscrollbarvalues`. You pass document minimum and maximum value and + topmost (leftmost) and bottommost (rightmost) visible values and it returns the + correct number or ``None``. + + +.. method:: ScrolledWindow.do_activate(onoff, event) + + Takes care of dimming/highlighting scrollbars when a window becomes frontmost. + If you override this method, call this one at the end of your method. + + +.. method:: ScrolledWindow.do_postresize(width, height, window) + + Moves scrollbars to the correct position. Call this method initially if you + override it. + + +.. method:: ScrolledWindow.do_controlhit(window, control, pcode, event) + + Handles scrollbar interaction. If you override it call this method first, a + nonzero return value indicates the hit was in the scrollbars and has been + handled. + + +.. _dialogwindow-objects: + +DialogWindow Objects +-------------------- + +DialogWindow objects have the following methods besides those of ``Window`` +objects: + + +.. method:: DialogWindow.open(resid) + + Create the dialog window, from the DLOG resource with id *resid*. The dialog + object is stored in :attr:`self.wid`. + + +.. method:: DialogWindow.do_itemhit(item, event) + + Item number *item* was hit. You are responsible for redrawing toggle buttons, + etc. + diff --git a/Doc/library/frameworks.rst b/Doc/library/frameworks.rst new file mode 100644 index 0000000..5d8dad5 --- /dev/null +++ b/Doc/library/frameworks.rst @@ -0,0 +1,18 @@ + +.. _frameworks: + +****************** +Program Frameworks +****************** + +The modules described in this chapter are frameworks that will largely dictate +the structure of your program. Currently the modules described here are all +oriented toward writing command-line interfaces. + +The full list of modules described in this chapter is: + + +.. toctree:: + + cmd.rst + shlex.rst diff --git a/Doc/library/ftplib.rst b/Doc/library/ftplib.rst new file mode 100644 index 0000000..60e88cf --- /dev/null +++ b/Doc/library/ftplib.rst @@ -0,0 +1,320 @@ + +:mod:`ftplib` --- FTP protocol client +===================================== + +.. module:: ftplib + :synopsis: FTP protocol client (requires sockets). + + +.. index:: + pair: FTP; protocol + single: FTP; ftplib (standard module) + +This module defines the class :class:`FTP` and a few related items. The +:class:`FTP` class implements the client side of the FTP protocol. You can use +this to write Python programs that perform a variety of automated FTP jobs, such +as mirroring other ftp servers. It is also used by the module :mod:`urllib` to +handle URLs that use FTP. For more information on FTP (File Transfer Protocol), +see Internet :rfc:`959`. + +Here's a sample session using the :mod:`ftplib` module:: + + >>> from ftplib import FTP + >>> ftp = FTP('ftp.cwi.nl') # connect to host, default port + >>> ftp.login() # user anonymous, passwd anonymous@ + >>> ftp.retrlines('LIST') # list directory contents + total 24418 + drwxrwsr-x 5 ftp-usr pdmaint 1536 Mar 20 09:48 . + dr-xr-srwt 105 ftp-usr pdmaint 1536 Mar 21 14:32 .. + -rw-r--r-- 1 ftp-usr pdmaint 5305 Mar 20 09:48 INDEX + . + . + . + >>> ftp.retrbinary('RETR README', open('README', 'wb').write) + '226 Transfer complete.' + >>> ftp.quit() + +The module defines the following items: + + +.. class:: FTP([host[, user[, passwd[, acct[, timeout]]]]]) + + Return a new instance of the :class:`FTP` class. When *host* is given, the + method call ``connect(host)`` is made. When *user* is given, additionally the + method call ``login(user, passwd, acct)`` is made (where *passwd* and *acct* + default to the empty string when not given). The optional *timeout* parameter + specifies a timeout in seconds for the connection attempt (if is not specified, + or passed as None, the global default timeout setting will be used). + + .. versionchanged:: 2.6 + *timeout* was added. + + +.. data:: all_errors + + The set of all exceptions (as a tuple) that methods of :class:`FTP` instances + may raise as a result of problems with the FTP connection (as opposed to + programming errors made by the caller). This set includes the four exceptions + listed below as well as :exc:`socket.error` and :exc:`IOError`. + + +.. exception:: error_reply + + Exception raised when an unexpected reply is received from the server. + + +.. exception:: error_temp + + Exception raised when an error code in the range 400--499 is received. + + +.. exception:: error_perm + + Exception raised when an error code in the range 500--599 is received. + + +.. exception:: error_proto + + Exception raised when a reply is received from the server that does not begin + with a digit in the range 1--5. + + +.. seealso:: + + Module :mod:`netrc` + Parser for the :file:`.netrc` file format. The file :file:`.netrc` is typically + used by FTP clients to load user authentication information before prompting the + user. + + .. index:: single: ftpmirror.py + + The file :file:`Tools/scripts/ftpmirror.py` in the Python source distribution is + a script that can mirror FTP sites, or portions thereof, using the :mod:`ftplib` + module. It can be used as an extended example that applies this module. + + +.. _ftp-objects: + +FTP Objects +----------- + +Several methods are available in two flavors: one for handling text files and +another for binary files. These are named for the command which is used +followed by ``lines`` for the text version or ``binary`` for the binary version. + +:class:`FTP` instances have the following methods: + + +.. method:: FTP.set_debuglevel(level) + + Set the instance's debugging level. This controls the amount of debugging + output printed. The default, ``0``, produces no debugging output. A value of + ``1`` produces a moderate amount of debugging output, generally a single line + per request. A value of ``2`` or higher produces the maximum amount of + debugging output, logging each line sent and received on the control connection. + + +.. method:: FTP.connect(host[, port[, timeout]]) + + Connect to the given host and port. The default port number is ``21``, as + specified by the FTP protocol specification. It is rarely needed to specify a + different port number. This function should be called only once for each + instance; it should not be called at all if a host was given when the instance + was created. All other methods can only be used after a connection has been + made. + + The optional *timeout* parameter specifies a timeout in seconds for the + connection attempt. If is not specified, or passed as None, the object timeout + is used (the timeout that you passed when instantiating the class); if the + object timeout is also None, the global default timeout setting will be used. + + .. versionchanged:: 2.6 + *timeout* was added. + + +.. method:: FTP.getwelcome() + + Return the welcome message sent by the server in reply to the initial + connection. (This message sometimes contains disclaimers or help information + that may be relevant to the user.) + + +.. method:: FTP.login([user[, passwd[, acct]]]) + + Log in as the given *user*. The *passwd* and *acct* parameters are optional and + default to the empty string. If no *user* is specified, it defaults to + ``'anonymous'``. If *user* is ``'anonymous'``, the default *passwd* is + ``'anonymous@'``. This function should be called only once for each instance, + after a connection has been established; it should not be called at all if a + host and user were given when the instance was created. Most FTP commands are + only allowed after the client has logged in. + + +.. method:: FTP.abort() + + Abort a file transfer that is in progress. Using this does not always work, but + it's worth a try. + + +.. method:: FTP.sendcmd(command) + + Send a simple command string to the server and return the response string. + + +.. method:: FTP.voidcmd(command) + + Send a simple command string to the server and handle the response. Return + nothing if a response code in the range 200--299 is received. Raise an exception + otherwise. + + +.. method:: FTP.retrbinary(command, callback[, maxblocksize[, rest]]) + + Retrieve a file in binary transfer mode. *command* should be an appropriate + ``RETR`` command: ``'RETR filename'``. The *callback* function is called for + each block of data received, with a single string argument giving the data + block. The optional *maxblocksize* argument specifies the maximum chunk size to + read on the low-level socket object created to do the actual transfer (which + will also be the largest size of the data blocks passed to *callback*). A + reasonable default is chosen. *rest* means the same thing as in the + :meth:`transfercmd` method. + + +.. method:: FTP.retrlines(command[, callback]) + + Retrieve a file or directory listing in ASCII transfer mode. *command* should be + an appropriate ``RETR`` command (see :meth:`retrbinary`) or a ``LIST`` command + (usually just the string ``'LIST'``). The *callback* function is called for + each line, with the trailing CRLF stripped. The default *callback* prints the + line to ``sys.stdout``. + + +.. method:: FTP.set_pasv(boolean) + + Enable "passive" mode if *boolean* is true, other disable passive mode. (In + Python 2.0 and before, passive mode was off by default; in Python 2.1 and later, + it is on by default.) + + +.. method:: FTP.storbinary(command, file[, blocksize]) + + Store a file in binary transfer mode. *command* should be an appropriate + ``STOR`` command: ``"STOR filename"``. *file* is an open file object which is + read until EOF using its :meth:`read` method in blocks of size *blocksize* to + provide the data to be stored. The *blocksize* argument defaults to 8192. + + .. versionchanged:: 2.1 + default for *blocksize* added. + + +.. method:: FTP.storlines(command, file) + + Store a file in ASCII transfer mode. *command* should be an appropriate + ``STOR`` command (see :meth:`storbinary`). Lines are read until EOF from the + open file object *file* using its :meth:`readline` method to provide the data to + be stored. + + +.. method:: FTP.transfercmd(cmd[, rest]) + + Initiate a transfer over the data connection. If the transfer is active, send a + ``EPRT`` or ``PORT`` command and the transfer command specified by *cmd*, and + accept the connection. If the server is passive, send a ``EPSV`` or ``PASV`` + command, connect to it, and start the transfer command. Either way, return the + socket for the connection. + + If optional *rest* is given, a ``REST`` command is sent to the server, passing + *rest* as an argument. *rest* is usually a byte offset into the requested file, + telling the server to restart sending the file's bytes at the requested offset, + skipping over the initial bytes. Note however that RFC 959 requires only that + *rest* be a string containing characters in the printable range from ASCII code + 33 to ASCII code 126. The :meth:`transfercmd` method, therefore, converts + *rest* to a string, but no check is performed on the string's contents. If the + server does not recognize the ``REST`` command, an :exc:`error_reply` exception + will be raised. If this happens, simply call :meth:`transfercmd` without a + *rest* argument. + + +.. method:: FTP.ntransfercmd(cmd[, rest]) + + Like :meth:`transfercmd`, but returns a tuple of the data connection and the + expected size of the data. If the expected size could not be computed, ``None`` + will be returned as the expected size. *cmd* and *rest* means the same thing as + in :meth:`transfercmd`. + + +.. method:: FTP.nlst(argument[, ...]) + + Return a list of files as returned by the ``NLST`` command. The optional + *argument* is a directory to list (default is the current server directory). + Multiple arguments can be used to pass non-standard options to the ``NLST`` + command. + + +.. method:: FTP.dir(argument[, ...]) + + Produce a directory listing as returned by the ``LIST`` command, printing it to + standard output. The optional *argument* is a directory to list (default is the + current server directory). Multiple arguments can be used to pass non-standard + options to the ``LIST`` command. If the last argument is a function, it is used + as a *callback* function as for :meth:`retrlines`; the default prints to + ``sys.stdout``. This method returns ``None``. + + +.. method:: FTP.rename(fromname, toname) + + Rename file *fromname* on the server to *toname*. + + +.. method:: FTP.delete(filename) + + Remove the file named *filename* from the server. If successful, returns the + text of the response, otherwise raises :exc:`error_perm` on permission errors or + :exc:`error_reply` on other errors. + + +.. method:: FTP.cwd(pathname) + + Set the current directory on the server. + + +.. method:: FTP.mkd(pathname) + + Create a new directory on the server. + + +.. method:: FTP.pwd() + + Return the pathname of the current directory on the server. + + +.. method:: FTP.rmd(dirname) + + Remove the directory named *dirname* on the server. + + +.. method:: FTP.size(filename) + + Request the size of the file named *filename* on the server. On success, the + size of the file is returned as an integer, otherwise ``None`` is returned. + Note that the ``SIZE`` command is not standardized, but is supported by many + common server implementations. + + +.. method:: FTP.quit() + + Send a ``QUIT`` command to the server and close the connection. This is the + "polite" way to close a connection, but it may raise an exception of the server + reponds with an error to the ``QUIT`` command. This implies a call to the + :meth:`close` method which renders the :class:`FTP` instance useless for + subsequent calls (see below). + + +.. method:: FTP.close() + + Close the connection unilaterally. This should not be applied to an already + closed connection such as after a successful call to :meth:`quit`. After this + call the :class:`FTP` instance should not be used any more (after a call to + :meth:`close` or :meth:`quit` you cannot reopen the connection by issuing + another :meth:`login` method). + diff --git a/Doc/library/functions.rst b/Doc/library/functions.rst new file mode 100644 index 0000000..b0a5577c --- /dev/null +++ b/Doc/library/functions.rst @@ -0,0 +1,1138 @@ + +.. _built-in-funcs: + +Built-in Functions +================== + +The Python interpreter has a number of functions built into it that are always +available. They are listed here in alphabetical order. + + +.. function:: __import__(name[, globals[, locals[, fromlist[, level]]]]) + + .. index:: + statement: import + module: ihooks + module: rexec + module: imp + + .. note:: + + This is an advanced function that is not needed in everyday Python + programming. + + The function is invoked by the :keyword:`import` statement. It mainly exists + so that you can replace it with another function that has a compatible + interface, in order to change the semantics of the :keyword:`import` statement. + For examples of why and how you would do this, see the standard library modules + :mod:`ihooks` and :mod:`rexec`. See also the built-in module :mod:`imp`, which + defines some useful operations out of which you can build your own + :func:`__import__` function. + + For example, the statement ``import spam`` results in the following call: + ``__import__('spam',`` ``globals(),`` ``locals(), [], -1)``; the statement + ``from spam.ham import eggs`` results in ``__import__('spam.ham', globals(), + locals(), ['eggs'], -1)``. Note that even though ``locals()`` and ``['eggs']`` + are passed in as arguments, the :func:`__import__` function does not set the + local variable named ``eggs``; this is done by subsequent code that is generated + for the import statement. (In fact, the standard implementation does not use + its *locals* argument at all, and uses its *globals* only to determine the + package context of the :keyword:`import` statement.) + + When the *name* variable is of the form ``package.module``, normally, the + top-level package (the name up till the first dot) is returned, *not* the + module named by *name*. However, when a non-empty *fromlist* argument is + given, the module named by *name* is returned. This is done for + compatibility with the bytecode generated for the different kinds of import + statement; when using ``import spam.ham.eggs``, the top-level package + :mod:`spam` must be placed in the importing namespace, but when using ``from + spam.ham import eggs``, the ``spam.ham`` subpackage must be used to find the + ``eggs`` variable. As a workaround for this behavior, use :func:`getattr` to + extract the desired components. For example, you could define the following + helper:: + + def my_import(name): + mod = __import__(name) + components = name.split('.') + for comp in components[1:]: + mod = getattr(mod, comp) + return mod + + *level* specifies whether to use absolute or relative imports. The default is + ``-1`` which indicates both absolute and relative imports will be attempted. + ``0`` means only perform absolute imports. Positive values for *level* indicate + the number of parent directories to search relative to the directory of the + module calling :func:`__import__`. + + .. versionchanged:: 2.5 + The level parameter was added. + + .. versionchanged:: 2.5 + Keyword support for parameters was added. + + +.. function:: abs(x) + + Return the absolute value of a number. The argument may be a plain or long + integer or a floating point number. If the argument is a complex number, its + magnitude is returned. + + +.. function:: all(iterable) + + Return True if all elements of the *iterable* are true. Equivalent to:: + + def all(iterable): + for element in iterable: + if not element: + return False + return True + + .. versionadded:: 2.5 + + +.. function:: any(iterable) + + Return True if any element of the *iterable* is true. Equivalent to:: + + def any(iterable): + for element in iterable: + if element: + return True + return False + + .. versionadded:: 2.5 + + +.. function:: basestring() + + This abstract type is the superclass for :class:`str`. It + cannot be called or instantiated, but it can be used to test whether an object + is an instance of :class:`str` (or a user-defined type inherited from + :class:`basestring`). + + .. versionadded:: 2.3 + + +.. function:: bin(x) + + Convert an integer number to a binary string. The result is a valid Python + expression. If *x* is not a Python :class:`int` object, it has to define an + :meth:`__index__` method that returns an integer. + + .. versionadded:: 3.0 + + +.. function:: bool([x]) + + Convert a value to a Boolean, using the standard truth testing procedure. If + *x* is false or omitted, this returns :const:`False`; otherwise it returns + :const:`True`. :class:`bool` is also a class, which is a subclass of + :class:`int`. Class :class:`bool` cannot be subclassed further. Its only + instances are :const:`False` and :const:`True`. + + .. index:: pair: Boolean; type + + .. versionadded:: 2.2.1 + + .. versionchanged:: 2.3 + If no argument is given, this function returns :const:`False`. + + +.. function:: chr(i) + + Return the string of one character whose Unicode codepoint is the integer *i*. For + example, ``chr(97)`` returns the string ``'a'``. This is the inverse of + :func:`ord`. The valid range for the argument depends how Python was + configured -- it may be either UCS2 [0..0xFFFF] or UCS4 [0..0x10FFFF]. + :exc:`ValueError` will be raised if *i* is outside that range. + + +.. function:: classmethod(function) + + Return a class method for *function*. + + A class method receives the class as implicit first argument, just like an + instance method receives the instance. To declare a class method, use this + idiom:: + + class C: + @classmethod + def f(cls, arg1, arg2, ...): ... + + The ``@classmethod`` form is a function decorator -- see the description of + function definitions in :ref:`function` for details. + + It can be called either on the class (such as ``C.f()``) or on an instance (such + as ``C().f()``). The instance is ignored except for its class. If a class + method is called for a derived class, the derived class object is passed as the + implied first argument. + + Class methods are different than C++ or Java static methods. If you want those, + see :func:`staticmethod` in this section. + + For more information on class methods, consult the documentation on the standard + type hierarchy in :ref:`types`. + + .. versionadded:: 2.2 + + .. versionchanged:: 2.4 + Function decorator syntax added. + + +.. function:: cmp(x, y) + + Compare the two objects *x* and *y* and return an integer according to the + outcome. The return value is negative if ``x < y``, zero if ``x == y`` and + strictly positive if ``x > y``. + + +.. function:: compile(source, filename, mode[, flags[, dont_inherit]]) + + Compile the *source* into a code object. Code objects can be executed by a call + to :func:`exec` or evaluated by a call to :func:`eval`. The *filename* argument + should give the file from which the code was read; pass some recognizable value + if it wasn't read from a file (``''`` is commonly used). The *mode* + argument specifies what kind of code must be compiled; it can be ``'exec'`` if + *source* consists of a sequence of statements, ``'eval'`` if it consists of a + single expression, or ``'single'`` if it consists of a single interactive + statement (in the latter case, expression statements that evaluate to something + else than ``None`` will be printed). + + When compiling multi-line statements, two caveats apply: line endings must be + represented by a single newline character (``'\n'``), and the input must be + terminated by at least one newline character. If line endings are represented + by ``'\r\n'``, use the string :meth:`replace` method to change them into + ``'\n'``. + + The optional arguments *flags* and *dont_inherit* (which are new in Python 2.2) + control which future statements (see :pep:`236`) affect the compilation of + *source*. If neither is present (or both are zero) the code is compiled with + those future statements that are in effect in the code that is calling compile. + If the *flags* argument is given and *dont_inherit* is not (or is zero) then the + future statements specified by the *flags* argument are used in addition to + those that would be used anyway. If *dont_inherit* is a non-zero integer then + the *flags* argument is it -- the future statements in effect around the call to + compile are ignored. + + Future statements are specified by bits which can be bitwise or-ed together to + specify multiple statements. The bitfield required to specify a given feature + can be found as the :attr:`compiler_flag` attribute on the :class:`_Feature` + instance in the :mod:`__future__` module. + + +.. function:: complex([real[, imag]]) + + Create a complex number with the value *real* + *imag*\*j or convert a string or + number to a complex number. If the first parameter is a string, it will be + interpreted as a complex number and the function must be called without a second + parameter. The second parameter can never be a string. Each argument may be any + numeric type (including complex). If *imag* is omitted, it defaults to zero and + the function serves as a numeric conversion function like :func:`int`, + :func:`long` and :func:`float`. If both arguments are omitted, returns ``0j``. + + The complex type is described in :ref:`typesnumeric`. + + +.. function:: delattr(object, name) + + This is a relative of :func:`setattr`. The arguments are an object and a + string. The string must be the name of one of the object's attributes. The + function deletes the named attribute, provided the object allows it. For + example, ``delattr(x, 'foobar')`` is equivalent to ``del x.foobar``. + + +.. function:: dict([arg]) + :noindex: + + Create a new data dictionary, optionally with items taken from *arg*. + The dictionary type is described in :ref:`typesmapping`. + + For other containers see the built in :class:`list`, :class:`set`, and + :class:`tuple` classes, and the :mod:`collections` module. + + +.. function:: dir([object]) + + Without arguments, return the list of names in the current local scope. With an + argument, attempt to return a list of valid attributes for that object. + + If the object has a method named :meth:`__dir__`, this method will be called and + must return the list of attributes. This allows objects that implement a custom + :func:`__getattr__` or :func:`__getattribute__` function to customize the way + :func:`dir` reports their attributes. + + If the object does not provide :meth:`__dir__`, the function tries its best to + gather information from the object's :attr:`__dict__` attribute, if defined, and + from its type object. The resulting list is not necessarily complete, and may + be inaccurate when the object has a custom :func:`__getattr__`. + + The default :func:`dir` mechanism behaves differently with different types of + objects, as it attempts to produce the most relevant, rather than complete, + information: + + * If the object is a module object, the list contains the names of the module's + attributes. + + * If the object is a type or class object, the list contains the names of its + attributes, and recursively of the attributes of its bases. + + * Otherwise, the list contains the object's attributes' names, the names of its + class's attributes, and recursively of the attributes of its class's base + classes. + + The resulting list is sorted alphabetically. For example:: + + >>> import struct + >>> dir() + ['__builtins__', '__doc__', '__name__', 'struct'] + >>> dir(struct) + ['__doc__', '__name__', 'calcsize', 'error', 'pack', 'unpack'] + >>> class Foo(object): + ... def __dir__(self): + ... return ["kan", "ga", "roo"] + ... + >>> f = Foo() + >>> dir(f) + ['ga', 'kan', 'roo'] + + .. note:: + + Because :func:`dir` is supplied primarily as a convenience for use at an + interactive prompt, it tries to supply an interesting set of names more than it + tries to supply a rigorously or consistently defined set of names, and its + detailed behavior may change across releases. + + +.. function:: divmod(a, b) + + Take two (non complex) numbers as arguments and return a pair of numbers + consisting of their quotient and remainder when using long division. With mixed + operand types, the rules for binary arithmetic operators apply. For plain and + long integers, the result is the same as ``(a // b, a % b)``. For floating point + numbers the result is ``(q, a % b)``, where *q* is usually ``math.floor(a / b)`` + but may be 1 less than that. In any case ``q * b + a % b`` is very close to + *a*, if ``a % b`` is non-zero it has the same sign as *b*, and ``0 <= abs(a % b) + < abs(b)``. + + .. versionchanged:: 2.3 + Using :func:`divmod` with complex numbers is deprecated. + + +.. function:: enumerate(iterable) + + Return an enumerate object. *iterable* must be a sequence, an iterator, or some + other object which supports iteration. The :meth:`__next__` method of the + iterator returned by :func:`enumerate` returns a tuple containing a count (from + zero) and the corresponding value obtained from iterating over *iterable*. + :func:`enumerate` is useful for obtaining an indexed series: ``(0, seq[0])``, + ``(1, seq[1])``, ``(2, seq[2])``, .... For example:: + + >>> for i, season in enumerate(['Spring', 'Summer', 'Fall', 'Winter')]: + >>> print i, season + 0 Spring + 1 Summer + 2 Fall + 3 Winter + + .. versionadded:: 2.3 + + +.. function:: eval(expression[, globals[, locals]]) + + The arguments are a string and optional globals and locals. If provided, + *globals* must be a dictionary. If provided, *locals* can be any mapping + object. + + .. versionchanged:: 2.4 + formerly *locals* was required to be a dictionary. + + The *expression* argument is parsed and evaluated as a Python expression + (technically speaking, a condition list) using the *globals* and *locals* + dictionaries as global and local name space. If the *globals* dictionary is + present and lacks '__builtins__', the current globals are copied into *globals* + before *expression* is parsed. This means that *expression* normally has full + access to the standard :mod:`__builtin__` module and restricted environments are + propagated. If the *locals* dictionary is omitted it defaults to the *globals* + dictionary. If both dictionaries are omitted, the expression is executed in the + environment where :keyword:`eval` is called. The return value is the result of + the evaluated expression. Syntax errors are reported as exceptions. Example:: + + >>> x = 1 + >>> print eval('x+1') + 2 + + This function can also be used to execute arbitrary code objects (such as those + created by :func:`compile`). In this case pass a code object instead of a + string. The code object must have been compiled passing ``'eval'`` as the + *kind* argument. + + Hints: dynamic execution of statements is supported by the :func:`exec` + function. The :func:`globals` and :func:`locals` functions + returns the current global and local dictionary, respectively, which may be + useful to pass around for use by :func:`eval` or :func:`exec`. + + +.. function:: exec(object[, globals[, locals]]) + + This function supports dynamic execution of Python code. *object* must be either + a string, an open file object, or a code object. If it is a string, the string + is parsed as a suite of Python statements which is then executed (unless a + syntax error occurs). If it is an open file, the file is parsed until EOF and + executed. If it is a code object, it is simply executed. In all cases, the + code that's executed is expected to be valid as file input (see the section + "File input" in the Reference Manual). Be aware that the :keyword:`return` and + :keyword:`yield` statements may not be used outside of function definitions even + within the context of code passed to the :func:`exec` function. The return value + is ``None``. + + In all cases, if the optional parts are omitted, the code is executed in the + current scope. If only *globals* is provided, it must be a dictionary, which + will be used for both the global and the local variables. If *globals* and + *locals* are given, they are used for the global and local variables, + respectively. If provided, *locals* can be any mapping object. + + If the *globals* dictionary does not contain a value for the key + ``__builtins__``, a reference to the dictionary of the built-in module + :mod:`__builtin__` is inserted under that key. That way you can control what + builtins are available to the executed code by inserting your own + ``__builtins__`` dictionary into *globals* before passing it to :func:`exec`. + + .. note:: + + The built-in functions :func:`globals` and :func:`locals` return the current + global and local dictionary, respectively, which may be useful to pass around + for use as the second and third argument to :func:`exec`. + + .. warning:: + + The default *locals* act as described for function :func:`locals` below: + modifications to the default *locals* dictionary should not be attempted. Pass + an explicit *locals* dictionary if you need to see effects of the code on + *locals* after function :func:`execfile` returns. :func:`exec` cannot be + used reliably to modify a function's locals. + + +.. function:: filter(function, iterable) + + Construct a list from those elements of *iterable* for which *function* returns + true. *iterable* may be either a sequence, a container which supports + iteration, or an iterator, If *iterable* is a string or a tuple, the result + also has that type; otherwise it is always a list. If *function* is ``None``, + the identity function is assumed, that is, all elements of *iterable* that are + false are removed. + + Note that ``filter(function, iterable)`` is equivalent to ``[item for item in + iterable if function(item)]`` if function is not ``None`` and ``[item for item + in iterable if item]`` if function is ``None``. + + +.. function:: float([x]) + + Convert a string or a number to floating point. If the argument is a string, it + must contain a possibly signed decimal or floating point number, possibly + embedded in whitespace. Otherwise, the argument may be a plain or long integer + or a floating point number, and a floating point number with the same value + (within Python's floating point precision) is returned. If no argument is + given, returns ``0.0``. + + .. note:: + + .. index:: + single: NaN + single: Infinity + + When passing in a string, values for NaN and Infinity may be returned, depending + on the underlying C library. The specific set of strings accepted which cause + these values to be returned depends entirely on the C library and is known to + vary. + + The float type is described in :ref:`typesnumeric`. + +.. function:: frozenset([iterable]) + :noindex: + + Return a frozenset object, optionally with elements taken from *iterable*. + The frozenset type is described in :ref:`types-set`. + + For other containers see the built in :class:`dict`, :class:`list`, and + :class:`tuple` classes, and the :mod:`collections` module. + + .. versionadded:: 2.4 + + +.. function:: getattr(object, name[, default]) + + Return the value of the named attributed of *object*. *name* must be a string. + If the string is the name of one of the object's attributes, the result is the + value of that attribute. For example, ``getattr(x, 'foobar')`` is equivalent to + ``x.foobar``. If the named attribute does not exist, *default* is returned if + provided, otherwise :exc:`AttributeError` is raised. + + +.. function:: globals() + + Return a dictionary representing the current global symbol table. This is always + the dictionary of the current module (inside a function or method, this is the + module where it is defined, not the module from which it is called). + + +.. function:: hasattr(object, name) + + The arguments are an object and a string. The result is ``True`` if the string + is the name of one of the object's attributes, ``False`` if not. (This is + implemented by calling ``getattr(object, name)`` and seeing whether it raises an + exception or not.) + + +.. function:: hash(object) + + Return the hash value of the object (if it has one). Hash values are integers. + They are used to quickly compare dictionary keys during a dictionary lookup. + Numeric values that compare equal have the same hash value (even if they are of + different types, as is the case for 1 and 1.0). + + +.. function:: help([object]) + + Invoke the built-in help system. (This function is intended for interactive + use.) If no argument is given, the interactive help system starts on the + interpreter console. If the argument is a string, then the string is looked up + as the name of a module, function, class, method, keyword, or documentation + topic, and a help page is printed on the console. If the argument is any other + kind of object, a help page on the object is generated. + + .. versionadded:: 2.2 + + +.. function:: hex(x) + + Convert an integer number to a hexadecimal string. The result is a valid Python + expression. If *x* is not a Python :class:`int` object, it has to define an + :meth:`__index__` method that returns an integer. + + .. versionchanged:: 2.4 + Formerly only returned an unsigned literal. + + +.. function:: id(object) + + Return the "identity" of an object. This is an integer (or long integer) which + is guaranteed to be unique and constant for this object during its lifetime. + Two objects with non-overlapping lifetimes may have the same :func:`id` value. + (Implementation note: this is the address of the object.) + + +.. function:: int([x[, radix]]) + + Convert a string or number to an integer. If the argument is a string, it + must contain a possibly signed number of arbitrary size, + possibly embedded in whitespace. The *radix* parameter gives the base for the + conversion and may be any integer in the range [2, 36], or zero. If *radix* is + zero, the interpretation is the same as for integer literals. If *radix* is + specified and *x* is not a string, :exc:`TypeError` is raised. Otherwise, the + argument may be another integer, a floating point number or any other object + that has an :meth:`__int__` method. Conversion + of floating point numbers to integers truncates (towards zero). If no + arguments are given, returns ``0``. + + The integer type is described in :ref:`typesnumeric`. + + +.. function:: isinstance(object, classinfo) + + Return true if the *object* argument is an instance of the *classinfo* argument, + or of a (direct or indirect) subclass thereof. Also return true if *classinfo* + is a type object (new-style class) and *object* is an object of that type or of + a (direct or indirect) subclass thereof. If *object* is not a class instance or + an object of the given type, the function always returns false. If *classinfo* + is neither a class object nor a type object, it may be a tuple of class or type + objects, or may recursively contain other such tuples (other sequence types are + not accepted). If *classinfo* is not a class, type, or tuple of classes, types, + and such tuples, a :exc:`TypeError` exception is raised. + + .. versionchanged:: 2.2 + Support for a tuple of type information was added. + + +.. function:: issubclass(class, classinfo) + + Return true if *class* is a subclass (direct or indirect) of *classinfo*. A + class is considered a subclass of itself. *classinfo* may be a tuple of class + objects, in which case every entry in *classinfo* will be checked. In any other + case, a :exc:`TypeError` exception is raised. + + .. versionchanged:: 2.3 + Support for a tuple of type information was added. + + +.. function:: iter(o[, sentinel]) + + Return an iterator object. The first argument is interpreted very differently + depending on the presence of the second argument. Without a second argument, *o* + must be a collection object which supports the iteration protocol (the + :meth:`__iter__` method), or it must support the sequence protocol (the + :meth:`__getitem__` method with integer arguments starting at ``0``). If it + does not support either of those protocols, :exc:`TypeError` is raised. If the + second argument, *sentinel*, is given, then *o* must be a callable object. The + iterator created in this case will call *o* with no arguments for each call to + its :meth:`__next__` method; if the value returned is equal to *sentinel*, + :exc:`StopIteration` will be raised, otherwise the value will be returned. + + .. versionadded:: 2.2 + + +.. function:: len(s) + + Return the length (the number of items) of an object. The argument may be a + sequence (string, tuple or list) or a mapping (dictionary). + + +.. function:: list([iterable]) + + Return a list whose items are the same and in the same order as *iterable*'s + items. *iterable* may be either a sequence, a container that supports + iteration, or an iterator object. If *iterable* is already a list, a copy is + made and returned, similar to ``iterable[:]``. For instance, ``list('abc')`` + returns ``['a', 'b', 'c']`` and ``list( (1, 2, 3) )`` returns ``[1, 2, 3]``. If + no argument is given, returns a new empty list, ``[]``. + + :class:`list` is a mutable sequence type, as documented in + :ref:`typesseq`. For other containers see the built in :class:`dict`, + :class:`set`, and :class:`tuple` classes, and the :mod:`collections` module. + + +.. function:: locals() + + Update and return a dictionary representing the current local symbol table. + + .. warning:: + + The contents of this dictionary should not be modified; changes may not affect + the values of local variables used by the interpreter. + + Free variables are returned by *locals* when it is called in a function block. + Modifications of free variables may not affect the values used by the + interpreter. Free variables are not returned in class blocks. + + +.. function:: map(function, iterable, ...) + + Apply *function* to every item of *iterable* and return a list of the results. + If additional *iterable* arguments are passed, *function* must take that many + arguments and is applied to the items from all iterables in parallel. If one + iterable is shorter than another it is assumed to be extended with ``None`` + items. If *function* is ``None``, the identity function is assumed; if there + are multiple arguments, :func:`map` returns a list consisting of tuples + containing the corresponding items from all iterables (a kind of transpose + operation). The *iterable* arguments may be a sequence or any iterable object; + the result is always a list. + + +.. function:: max(iterable[, args...][key]) + + With a single argument *iterable*, return the largest item of a non-empty + iterable (such as a string, tuple or list). With more than one argument, return + the largest of the arguments. + + The optional *key* argument specifies a one-argument ordering function like that + used for :meth:`list.sort`. The *key* argument, if supplied, must be in keyword + form (for example, ``max(a,b,c,key=func)``). + + .. versionchanged:: 2.5 + Added support for the optional *key* argument. + + +.. function:: min(iterable[, args...][key]) + + With a single argument *iterable*, return the smallest item of a non-empty + iterable (such as a string, tuple or list). With more than one argument, return + the smallest of the arguments. + + The optional *key* argument specifies a one-argument ordering function like that + used for :meth:`list.sort`. The *key* argument, if supplied, must be in keyword + form (for example, ``min(a,b,c,key=func)``). + + .. versionchanged:: 2.5 + Added support for the optional *key* argument. + + +.. function:: next(iterator[, default]) + + Retrieve the next item from the *iterable* by calling its :meth:`__next__` + method. If *default* is given, it is returned if the iterator is exhausted, + otherwise :exc:`StopIteration` is raised. + + +.. function:: object() + + Return a new featureless object. :class:`object` is a base for all new style + classes. It has the methods that are common to all instances of new style + classes. + + .. versionadded:: 2.2 + + .. versionchanged:: 2.3 + This function does not accept any arguments. Formerly, it accepted arguments but + ignored them. + + +.. function:: oct(x) + + Convert an integer number to an octal string. The result is a valid Python + expression. If *x* is not a Python :class:`int` object, it has to define an + :meth:`__index__` method that returns an integer. + + .. versionchanged:: 2.4 + Formerly only returned an unsigned literal. + + +.. function:: open(filename[, mode[, bufsize]]) + + Open a file, returning an object of the :class:`file` type described in + section :ref:`bltin-file-objects`. If the file cannot be opened, + :exc:`IOError` is raised. When opening a file, it's preferable to use + :func:`open` instead of invoking the :class:`file` constructor directly. + + The first two arguments are the same as for ``stdio``'s :cfunc:`fopen`: + *filename* is the file name to be opened, and *mode* is a string indicating how + the file is to be opened. + + The most commonly-used values of *mode* are ``'r'`` for reading, ``'w'`` for + writing (truncating the file if it already exists), and ``'a'`` for appending + (which on *some* Unix systems means that *all* writes append to the end of the + file regardless of the current seek position). If *mode* is omitted, it + defaults to ``'r'``. When opening a binary file, you should append ``'b'`` to + the *mode* value to open the file in binary mode, which will improve + portability. (Appending ``'b'`` is useful even on systems that don't treat + binary and text files differently, where it serves as documentation.) See below + for more possible values of *mode*. + + .. index:: + single: line-buffered I/O + single: unbuffered I/O + single: buffer size, I/O + single: I/O control; buffering + + The optional *bufsize* argument specifies the file's desired buffer size: 0 + means unbuffered, 1 means line buffered, any other positive value means use a + buffer of (approximately) that size. A negative *bufsize* means to use the + system default, which is usually line buffered for tty devices and fully + buffered for other files. If omitted, the system default is used. [#]_ + + Modes ``'r+'``, ``'w+'`` and ``'a+'`` open the file for updating (note that + ``'w+'`` truncates the file). Append ``'b'`` to the mode to open the file in + binary mode, on systems that differentiate between binary and text files; on + systems that don't have this distinction, adding the ``'b'`` has no effect. + + In addition to the standard :cfunc:`fopen` values *mode* may be ``'U'`` or + ``'rU'``. Python is usually built with universal newline support; supplying + ``'U'`` opens the file as a text file, but lines may be terminated by any of the + following: the Unix end-of-line convention ``'\n'``, the Macintosh convention + ``'\r'``, or the Windows convention ``'\r\n'``. All of these external + representations are seen as ``'\n'`` by the Python program. If Python is built + without universal newline support a *mode* with ``'U'`` is the same as normal + text mode. Note that file objects so opened also have an attribute called + :attr:`newlines` which has a value of ``None`` (if no newlines have yet been + seen), ``'\n'``, ``'\r'``, ``'\r\n'``, or a tuple containing all the newline + types seen. + + Python enforces that the mode, after stripping ``'U'``, begins with ``'r'``, + ``'w'`` or ``'a'``. + + See also the :mod:`fileinput` module. + + .. versionchanged:: 2.5 + Restriction on first letter of mode string introduced. + + +.. function:: ord(c) + + Given a string of length one, return an integer representing the Unicode code + point of the character when the argument is a unicode object, or the value of + the byte when the argument is an 8-bit string. For example, ``ord('a')`` returns + the integer ``97``, ``ord(u'\u2020')`` returns ``8224``. This is the inverse of + :func:`chr` for 8-bit strings and of :func:`unichr` for unicode objects. If a + unicode argument is given and Python was built with UCS2 Unicode, then the + character's code point must be in the range [0..65535] inclusive; otherwise the + string length is two, and a :exc:`TypeError` will be raised. + + +.. function:: pow(x, y[, z]) + + Return *x* to the power *y*; if *z* is present, return *x* to the power *y*, + modulo *z* (computed more efficiently than ``pow(x, y) % z``). The two-argument + form ``pow(x, y)`` is equivalent to using the power operator: ``x**y``. + + The arguments must have numeric types. With mixed operand types, the coercion + rules for binary arithmetic operators apply. For int and long int operands, the + result has the same type as the operands (after coercion) unless the second + argument is negative; in that case, all arguments are converted to float and a + float result is delivered. For example, ``10**2`` returns ``100``, but + ``10**-2`` returns ``0.01``. (This last feature was added in Python 2.2. In + Python 2.1 and before, if both arguments were of integer types and the second + argument was negative, an exception was raised.) If the second argument is + negative, the third argument must be omitted. If *z* is present, *x* and *y* + must be of integer types, and *y* must be non-negative. (This restriction was + added in Python 2.2. In Python 2.1 and before, floating 3-argument ``pow()`` + returned platform-dependent results depending on floating-point rounding + accidents.) + + +.. function:: property([fget[, fset[, fdel[, doc]]]]) + + Return a property attribute for new-style classes (classes that derive from + :class:`object`). + + *fget* is a function for getting an attribute value, likewise *fset* is a + function for setting, and *fdel* a function for del'ing, an attribute. Typical + use is to define a managed attribute x:: + + class C(object): + def __init__(self): self._x = None + def getx(self): return self._x + def setx(self, value): self._x = value + def delx(self): del self._x + x = property(getx, setx, delx, "I'm the 'x' property.") + + If given, *doc* will be the docstring of the property attribute. Otherwise, the + property will copy *fget*'s docstring (if it exists). This makes it possible to + create read-only properties easily using :func:`property` as a decorator:: + + class Parrot(object): + def __init__(self): + self._voltage = 100000 + + @property + def voltage(self): + """Get the current voltage.""" + return self._voltage + + turns the :meth:`voltage` method into a "getter" for a read-only attribute with + the same name. + + .. versionadded:: 2.2 + + .. versionchanged:: 2.5 + Use *fget*'s docstring if no *doc* given. + + +.. function:: range([start,] stop[, step]) + + This is a versatile function to create sequences containing arithmetic + progressions. It is most often used in :keyword:`for` loops. The arguments + must be plain integers. If the *step* argument is omitted, it defaults to + ``1``. If the *start* argument is omitted, it defaults to ``0``. The full form + returns a list of plain integers ``[start, start + step, start + 2 * step, + ...]``. If *step* is positive, the last element is the largest ``start + i * + step`` less than *stop*; if *step* is negative, the last element is the smallest + ``start + i * step`` greater than *stop*. *step* must not be zero (or else + :exc:`ValueError` is raised). Example:: + + >>> list(range(10)) + [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] + >>> list(range(1, 11)) + [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] + >>> list(range(0, 30, 5)) + [0, 5, 10, 15, 20, 25] + >>> list(range(0, 10, 3)) + [0, 3, 6, 9] + >>> list(range(0, -10, -1)) + [0, -1, -2, -3, -4, -5, -6, -7, -8, -9] + >>> list(range(0)) + [] + >>> list(range(1, 0)) + [] + + +.. function:: repr(object) + + Return a string containing a printable representation of an object. This is the + same value yielded by conversions (reverse quotes). It is sometimes useful to be + able to access this operation as an ordinary function. For many types, this + function makes an attempt to return a string that would yield an object with the + same value when passed to :func:`eval`. + + +.. function:: reversed(seq) + + Return a reverse iterator. *seq* must be an object which supports the sequence + protocol (the :meth:`__len__` method and the :meth:`__getitem__` method with + integer arguments starting at ``0``). + + .. versionadded:: 2.4 + + +.. function:: round(x[, n]) + + Return the floating point value *x* rounded to *n* digits after the decimal + point. If *n* is omitted, it defaults to zero. The result is a floating point + number. Values are rounded to the closest multiple of 10 to the power minus + *n*; if two multiples are equally close, rounding is done away from 0 (so. for + example, ``round(0.5)`` is ``1.0`` and ``round(-0.5)`` is ``-1.0``). + + +.. function:: set([iterable]) + :noindex: + + Return a new set, optionally with elements are taken from *iterable*. + The set type is described in :ref:`types-set`. + + For other containers see the built in :class:`dict`, :class:`list`, and + :class:`tuple` classes, and the :mod:`collections` module. + + .. versionadded:: 2.4 + + +.. function:: setattr(object, name, value) + + This is the counterpart of :func:`getattr`. The arguments are an object, a + string and an arbitrary value. The string may name an existing attribute or a + new attribute. The function assigns the value to the attribute, provided the + object allows it. For example, ``setattr(x, 'foobar', 123)`` is equivalent to + ``x.foobar = 123``. + + +.. function:: slice([start,] stop[, step]) + + .. index:: single: Numerical Python + + Return a slice object representing the set of indices specified by + ``range(start, stop, step)``. The *start* and *step* arguments default to + ``None``. Slice objects have read-only data attributes :attr:`start`, + :attr:`stop` and :attr:`step` which merely return the argument values (or their + default). They have no other explicit functionality; however they are used by + Numerical Python and other third party extensions. Slice objects are also + generated when extended indexing syntax is used. For example: + ``a[start:stop:step]`` or ``a[start:stop, i]``. + + +.. function:: sorted(iterable[, cmp[, key[, reverse]]]) + + Return a new sorted list from the items in *iterable*. + + The optional arguments *cmp*, *key*, and *reverse* have the same meaning as + those for the :meth:`list.sort` method (described in section + :ref:`typesseq-mutable`). + + *cmp* specifies a custom comparison function of two arguments (iterable + elements) which should return a negative, zero or positive number depending on + whether the first argument is considered smaller than, equal to, or larger than + the second argument: ``cmp=lambda x,y: cmp(x.lower(), y.lower())`` + + *key* specifies a function of one argument that is used to extract a comparison + key from each list element: ``key=str.lower`` + + *reverse* is a boolean value. If set to ``True``, then the list elements are + sorted as if each comparison were reversed. + + In general, the *key* and *reverse* conversion processes are much faster than + specifying an equivalent *cmp* function. This is because *cmp* is called + multiple times for each list element while *key* and *reverse* touch each + element only once. + + .. versionadded:: 2.4 + + +.. function:: staticmethod(function) + + Return a static method for *function*. + + A static method does not receive an implicit first argument. To declare a static + method, use this idiom:: + + class C: + @staticmethod + def f(arg1, arg2, ...): ... + + The ``@staticmethod`` form is a function decorator -- see the description of + function definitions in :ref:`function` for details. + + It can be called either on the class (such as ``C.f()``) or on an instance (such + as ``C().f()``). The instance is ignored except for its class. + + Static methods in Python are similar to those found in Java or C++. For a more + advanced concept, see :func:`classmethod` in this section. + + For more information on static methods, consult the documentation on the + standard type hierarchy in :ref:`types`. + + .. versionadded:: 2.2 + + .. versionchanged:: 2.4 + Function decorator syntax added. + + +.. function:: str([object[, encoding[, errors]]]) + + Return a string version of an object, using one of the following modes: + + If *encoding* and/or *errors* are given, :func:`str` will decode the + *object* which can either be a byte string or a character buffer using + the codec for *encoding*. The *encoding* parameter is a string giving + the name of an encoding; if the encoding is not known, :exc:`LookupError` + is raised. Error handling is done according to *errors*; this specifies the + treatment of characters which are invalid in the input encoding. If + *errors* is ``'strict'`` (the default), a :exc:`ValueError` is raised on + errors, while a value of ``'ignore'`` causes errors to be silently ignored, + and a value of ``'replace'`` causes the official Unicode replacement character, + U+FFFD, to be used to replace input characters which cannot be decoded. + See also the :mod:`codecs` module. + + When only *object* is given, this returns its nicely printable representation. + For strings, this is the string itself. The difference with ``repr(object)`` + is that ``str(object)`` does not always attempt to return a string that is + acceptable to :func:`eval`; its goal is to return a printable string. + With no arguments, this returns the empty string. + + Objects can specify what ``str(object)`` returns by defining a :meth:`__str__` + special method. + + For more information on strings see :ref:`typesseq` which describes sequence + functionality (strings are sequences), and also the string-specific methods + described in the :ref:`string-methods` section. To output formatted strings + use template strings or the ``%`` operator described in the + :ref:`string-formatting` section. In addition see the :ref:`stringservices` + section. See also :func:`unicode`. + + +.. function:: sum(iterable[, start]) + + Sums *start* and the items of an *iterable* from left to right and returns the + total. *start* defaults to ``0``. The *iterable*'s items are normally numbers, + and are not allowed to be strings. The fast, correct way to concatenate a + sequence of strings is by calling ``''.join(sequence)``. + + .. versionadded:: 2.3 + + +.. function:: super(type[, object-or-type]) + + Return the superclass of *type*. If the second argument is omitted the super + object returned is unbound. If the second argument is an object, + ``isinstance(obj, type)`` must be true. If the second argument is a type, + ``issubclass(type2, type)`` must be true. :func:`super` only works for new-style + classes. + + A typical use for calling a cooperative superclass method is:: + + class C(B): + def meth(self, arg): + super(C, self).meth(arg) + + Note that :func:`super` is implemented as part of the binding process for + explicit dotted attribute lookups such as ``super(C, self).__getitem__(name)``. + Accordingly, :func:`super` is undefined for implicit lookups using statements or + operators such as ``super(C, self)[name]``. + + .. versionadded:: 2.2 + + +.. function:: tuple([iterable]) + + Return a tuple whose items are the same and in the same order as *iterable*'s + items. *iterable* may be a sequence, a container that supports iteration, or an + iterator object. If *iterable* is already a tuple, it is returned unchanged. + For instance, ``tuple('abc')`` returns ``('a', 'b', 'c')`` and ``tuple([1, 2, + 3])`` returns ``(1, 2, 3)``. If no argument is given, returns a new empty + tuple, ``()``. + + :class:`tuple` is an immutable sequence type, as documented in + :ref:`typesseq`. For other containers see the built in :class:`dict`, + :class:`list`, and :class:`set` classes, and the :mod:`collections` module. + + +.. function:: type(object) + + .. index:: object: type + + Return the type of an *object*. The return value is a type object. The + :func:`isinstance` built-in function is recommended for testing the type of an + object. + + With three arguments, :func:`type` functions as a constructor as detailed below. + + +.. function:: type(name, bases, dict) + :noindex: + + Return a new type object. This is essentially a dynamic form of the + :keyword:`class` statement. The *name* string is the class name and becomes the + :attr:`__name__` attribute; the *bases* tuple itemizes the base classes and + becomes the :attr:`__bases__` attribute; and the *dict* dictionary is the + namespace containing definitions for class body and becomes the :attr:`__dict__` + attribute. For example, the following two statements create identical + :class:`type` objects:: + + >>> class X(object): + ... a = 1 + ... + >>> X = type('X', (object,), dict(a=1)) + + .. versionadded:: 2.2 + + +.. function:: vars([object]) + + Without arguments, return a dictionary corresponding to the current local symbol + table. With a module, class or class instance object as argument (or anything + else that has a :attr:`__dict__` attribute), returns a dictionary corresponding + to the object's symbol table. The returned dictionary should not be modified: + the effects on the corresponding symbol table are undefined. [#]_ + + +.. function:: zip([iterable, ...]) + + This function returns a list of tuples, where the *i*-th tuple contains the + *i*-th element from each of the argument sequences or iterables. The returned + list is truncated in length to the length of the shortest argument sequence. + When there are multiple arguments which are all of the same length, :func:`zip` + is similar to :func:`map` with an initial argument of ``None``. With a single + sequence argument, it returns a list of 1-tuples. With no arguments, it returns + an empty list. + + .. versionadded:: 2.0 + + .. versionchanged:: 2.4 + Formerly, :func:`zip` required at least one argument and ``zip()`` raised a + :exc:`TypeError` instead of returning an empty list. + +.. % --------------------------------------------------------------------------- + + +.. _non-essential-built-in-funcs: + +Non-essential Built-in Functions +================================ + +There are several built-in functions that are no longer essential to learn, know +or use in modern Python programming. They have been kept here to maintain +backwards compatibility with programs written for older versions of Python. + +Python programmers, trainers, students and bookwriters should feel free to +bypass these functions without concerns about missing something important. + + +.. function:: buffer(object[, offset[, size]]) + + The *object* argument must be an object that supports the buffer call interface + (such as strings, arrays, and buffers). A new buffer object will be created + which references the *object* argument. The buffer object will be a slice from + the beginning of *object* (or from the specified *offset*). The slice will + extend to the end of *object* (or will have a length given by the *size* + argument). + + + +.. rubric:: Footnotes + +.. [#] Specifying a buffer size currently has no effect on systems that don't have + :cfunc:`setvbuf`. The interface to specify the buffer size is not done using a + method that calls :cfunc:`setvbuf`, because that may dump core when called after + any I/O has been performed, and there's no reliable way to determine whether + this is the case. + +.. [#] In the current implementation, local variable bindings cannot normally be + affected this way, but variables retrieved from other scopes (such as modules) + can be. This may change. + diff --git a/Doc/library/functools.rst b/Doc/library/functools.rst new file mode 100644 index 0000000..4874b55 --- /dev/null +++ b/Doc/library/functools.rst @@ -0,0 +1,145 @@ +:mod:`functools` --- Higher order functions and operations on callable objects +============================================================================== + +.. module:: functools + :synopsis: Higher order functions and operations on callable objects. +.. moduleauthor:: Peter Harris +.. moduleauthor:: Raymond Hettinger +.. moduleauthor:: Nick Coghlan +.. sectionauthor:: Peter Harris + + +.. versionadded:: 2.5 + +The :mod:`functools` module is for higher-order functions: functions that act on +or return other functions. In general, any callable object can be treated as a +function for the purposes of this module. + +The :mod:`functools` module defines the following function: + + +.. function:: partial(func[,*args][, **keywords]) + + Return a new :class:`partial` object which when called will behave like *func* + called with the positional arguments *args* and keyword arguments *keywords*. If + more arguments are supplied to the call, they are appended to *args*. If + additional keyword arguments are supplied, they extend and override *keywords*. + Roughly equivalent to:: + + def partial(func, *args, **keywords): + def newfunc(*fargs, **fkeywords): + newkeywords = keywords.copy() + newkeywords.update(fkeywords) + return func(*(args + fargs), **newkeywords) + newfunc.func = func + newfunc.args = args + newfunc.keywords = keywords + return newfunc + + The :func:`partial` is used for partial function application which "freezes" + some portion of a function's arguments and/or keywords resulting in a new object + with a simplified signature. For example, :func:`partial` can be used to create + a callable that behaves like the :func:`int` function where the *base* argument + defaults to two:: + + >>> basetwo = partial(int, base=2) + >>> basetwo.__doc__ = 'Convert base 2 string to an int.' + >>> basetwo('10010') + 18 + + +.. function:: reduce(function, sequence[, initializer]) + + Apply *function* of two arguments cumulatively to the items of *sequence*, from + left to right, so as to reduce the sequence to a single value. For example, + ``reduce(lambda x, y: x+y, [1, 2, 3, 4, 5])`` calculates ``((((1+2)+3)+4)+5)``. + The left argument, *x*, is the accumulated value and the right argument, *y*, is + the update value from the *sequence*. If the optional *initializer* is present, + it is placed before the items of the sequence in the calculation, and serves as + a default when the sequence is empty. If *initializer* is not given and + *sequence* contains only one item, the first item is returned. + + +.. function:: update_wrapper(wrapper, wrapped[, assigned][, updated]) + + Update a *wrapper* function to look like the *wrapped* function. The optional + arguments are tuples to specify which attributes of the original function are + assigned directly to the matching attributes on the wrapper function and which + attributes of the wrapper function are updated with the corresponding attributes + from the original function. The default values for these arguments are the + module level constants *WRAPPER_ASSIGNMENTS* (which assigns to the wrapper + function's *__name__*, *__module__* and *__doc__*, the documentation string) and + *WRAPPER_UPDATES* (which updates the wrapper function's *__dict__*, i.e. the + instance dictionary). + + The main intended use for this function is in decorator functions which wrap the + decorated function and return the wrapper. If the wrapper function is not + updated, the metadata of the returned function will reflect the wrapper + definition rather than the original function definition, which is typically less + than helpful. + + +.. function:: wraps(wrapped[, assigned][, updated]) + + This is a convenience function for invoking ``partial(update_wrapper, + wrapped=wrapped, assigned=assigned, updated=updated)`` as a function decorator + when defining a wrapper function. For example:: + + >>> def my_decorator(f): + ... @wraps(f) + ... def wrapper(*args, **kwds): + ... print 'Calling decorated function' + ... return f(*args, **kwds) + ... return wrapper + ... + >>> @my_decorator + ... def example(): + ... """Docstring""" + ... print 'Called example function' + ... + >>> example() + Calling decorated function + Called example function + >>> example.__name__ + 'example' + >>> example.__doc__ + 'Docstring' + + Without the use of this decorator factory, the name of the example function + would have been ``'wrapper'``, and the docstring of the original :func:`example` + would have been lost. + + +.. _partial-objects: + +:class:`partial` Objects +------------------------ + +:class:`partial` objects are callable objects created by :func:`partial`. They +have three read-only attributes: + + +.. attribute:: partial.func + + A callable object or function. Calls to the :class:`partial` object will be + forwarded to :attr:`func` with new arguments and keywords. + + +.. attribute:: partial.args + + The leftmost positional arguments that will be prepended to the positional + arguments provided to a :class:`partial` object call. + + +.. attribute:: partial.keywords + + The keyword arguments that will be supplied when the :class:`partial` object is + called. + +:class:`partial` objects are like :class:`function` objects in that they are +callable, weak referencable, and can have attributes. There are some important +differences. For instance, the :attr:`__name__` and :attr:`__doc__` attributes +are not created automatically. Also, :class:`partial` objects defined in +classes behave like static methods and do not transform into bound methods +during instance attribute look-up. + diff --git a/Doc/library/gc.rst b/Doc/library/gc.rst new file mode 100644 index 0000000..70e4a6b --- /dev/null +++ b/Doc/library/gc.rst @@ -0,0 +1,211 @@ + +:mod:`gc` --- Garbage Collector interface +========================================= + +.. module:: gc + :synopsis: Interface to the cycle-detecting garbage collector. +.. moduleauthor:: Neil Schemenauer +.. sectionauthor:: Neil Schemenauer + + +This module provides an interface to the optional garbage collector. It +provides the ability to disable the collector, tune the collection frequency, +and set debugging options. It also provides access to unreachable objects that +the collector found but cannot free. Since the collector supplements the +reference counting already used in Python, you can disable the collector if you +are sure your program does not create reference cycles. Automatic collection +can be disabled by calling ``gc.disable()``. To debug a leaking program call +``gc.set_debug(gc.DEBUG_LEAK)``. Notice that this includes +``gc.DEBUG_SAVEALL``, causing garbage-collected objects to be saved in +gc.garbage for inspection. + +The :mod:`gc` module provides the following functions: + + +.. function:: enable() + + Enable automatic garbage collection. + + +.. function:: disable() + + Disable automatic garbage collection. + + +.. function:: isenabled() + + Returns true if automatic collection is enabled. + + +.. function:: collect([generation]) + + With no arguments, run a full collection. The optional argument *generation* + may be an integer specifying which generation to collect (from 0 to 2). A + :exc:`ValueError` is raised if the generation number is invalid. The number of + unreachable objects found is returned. + + .. versionchanged:: 2.5 + The optional *generation* argument was added. + + +.. function:: set_debug(flags) + + Set the garbage collection debugging flags. Debugging information will be + written to ``sys.stderr``. See below for a list of debugging flags which can be + combined using bit operations to control debugging. + + +.. function:: get_debug() + + Return the debugging flags currently set. + + +.. function:: get_objects() + + Returns a list of all objects tracked by the collector, excluding the list + returned. + + .. versionadded:: 2.2 + + +.. function:: set_threshold(threshold0[, threshold1[, threshold2]]) + + Set the garbage collection thresholds (the collection frequency). Setting + *threshold0* to zero disables collection. + + The GC classifies objects into three generations depending on how many + collection sweeps they have survived. New objects are placed in the youngest + generation (generation ``0``). If an object survives a collection it is moved + into the next older generation. Since generation ``2`` is the oldest + generation, objects in that generation remain there after a collection. In + order to decide when to run, the collector keeps track of the number object + allocations and deallocations since the last collection. When the number of + allocations minus the number of deallocations exceeds *threshold0*, collection + starts. Initially only generation ``0`` is examined. If generation ``0`` has + been examined more than *threshold1* times since generation ``1`` has been + examined, then generation ``1`` is examined as well. Similarly, *threshold2* + controls the number of collections of generation ``1`` before collecting + generation ``2``. + + +.. function:: get_count() + + Return the current collection counts as a tuple of ``(count0, count1, + count2)``. + + .. versionadded:: 2.5 + + +.. function:: get_threshold() + + Return the current collection thresholds as a tuple of ``(threshold0, + threshold1, threshold2)``. + + +.. function:: get_referrers(*objs) + + Return the list of objects that directly refer to any of objs. This function + will only locate those containers which support garbage collection; extension + types which do refer to other objects but do not support garbage collection will + not be found. + + Note that objects which have already been dereferenced, but which live in cycles + and have not yet been collected by the garbage collector can be listed among the + resulting referrers. To get only currently live objects, call :func:`collect` + before calling :func:`get_referrers`. + + Care must be taken when using objects returned by :func:`get_referrers` because + some of them could still be under construction and hence in a temporarily + invalid state. Avoid using :func:`get_referrers` for any purpose other than + debugging. + + .. versionadded:: 2.2 + + +.. function:: get_referents(*objs) + + Return a list of objects directly referred to by any of the arguments. The + referents returned are those objects visited by the arguments' C-level + :attr:`tp_traverse` methods (if any), and may not be all objects actually + directly reachable. :attr:`tp_traverse` methods are supported only by objects + that support garbage collection, and are only required to visit objects that may + be involved in a cycle. So, for example, if an integer is directly reachable + from an argument, that integer object may or may not appear in the result list. + + .. versionadded:: 2.3 + +The following variable is provided for read-only access (you can mutate its +value but should not rebind it): + + +.. data:: garbage + + A list of objects which the collector found to be unreachable but could not be + freed (uncollectable objects). By default, this list contains only objects with + :meth:`__del__` methods. [#]_ Objects that have :meth:`__del__` methods and are + part of a reference cycle cause the entire reference cycle to be uncollectable, + including objects not necessarily in the cycle but reachable only from it. + Python doesn't collect such cycles automatically because, in general, it isn't + possible for Python to guess a safe order in which to run the :meth:`__del__` + methods. If you know a safe order, you can force the issue by examining the + *garbage* list, and explicitly breaking cycles due to your objects within the + list. Note that these objects are kept alive even so by virtue of being in the + *garbage* list, so they should be removed from *garbage* too. For example, + after breaking cycles, do ``del gc.garbage[:]`` to empty the list. It's + generally better to avoid the issue by not creating cycles containing objects + with :meth:`__del__` methods, and *garbage* can be examined in that case to + verify that no such cycles are being created. + + If :const:`DEBUG_SAVEALL` is set, then all unreachable objects will be added to + this list rather than freed. + +The following constants are provided for use with :func:`set_debug`: + + +.. data:: DEBUG_STATS + + Print statistics during collection. This information can be useful when tuning + the collection frequency. + + +.. data:: DEBUG_COLLECTABLE + + Print information on collectable objects found. + + +.. data:: DEBUG_UNCOLLECTABLE + + Print information of uncollectable objects found (objects which are not + reachable but cannot be freed by the collector). These objects will be added to + the ``garbage`` list. + + +.. data:: DEBUG_INSTANCES + + When :const:`DEBUG_COLLECTABLE` or :const:`DEBUG_UNCOLLECTABLE` is set, print + information about instance objects found. + + +.. data:: DEBUG_OBJECTS + + When :const:`DEBUG_COLLECTABLE` or :const:`DEBUG_UNCOLLECTABLE` is set, print + information about objects other than instance objects found. + + +.. data:: DEBUG_SAVEALL + + When set, all unreachable objects found will be appended to *garbage* rather + than being freed. This can be useful for debugging a leaking program. + + +.. data:: DEBUG_LEAK + + The debugging flags necessary for the collector to print information about a + leaking program (equal to ``DEBUG_COLLECTABLE | DEBUG_UNCOLLECTABLE | + DEBUG_INSTANCES | DEBUG_OBJECTS | DEBUG_SAVEALL``). + +.. rubric:: Footnotes + +.. [#] Prior to Python 2.2, the list contained all instance objects in unreachable + cycles, not only those with :meth:`__del__` methods. + diff --git a/Doc/library/gdbm.rst b/Doc/library/gdbm.rst new file mode 100644 index 0000000..ce27f6c --- /dev/null +++ b/Doc/library/gdbm.rst @@ -0,0 +1,122 @@ + +:mod:`gdbm` --- GNU's reinterpretation of dbm +============================================= + +.. module:: gdbm + :platform: Unix + :synopsis: GNU's reinterpretation of dbm. + + +.. index:: module: dbm + +This module is quite similar to the :mod:`dbm` module, but uses ``gdbm`` instead +to provide some additional functionality. Please note that the file formats +created by ``gdbm`` and ``dbm`` are incompatible. + +The :mod:`gdbm` module provides an interface to the GNU DBM library. ``gdbm`` +objects behave like mappings (dictionaries), except that keys and values are +always strings. Printing a ``gdbm`` object doesn't print the keys and values, +and the :meth:`items` and :meth:`values` methods are not supported. + +The module defines the following constant and functions: + + +.. exception:: error + + Raised on ``gdbm``\ -specific errors, such as I/O errors. :exc:`KeyError` is + raised for general mapping errors like specifying an incorrect key. + + +.. function:: open(filename, [flag, [mode]]) + + Open a ``gdbm`` database and return a ``gdbm`` object. The *filename* argument + is the name of the database file. + + The optional *flag* argument can be: + + +---------+-------------------------------------------+ + | Value | Meaning | + +=========+===========================================+ + | ``'r'`` | Open existing database for reading only | + | | (default) | + +---------+-------------------------------------------+ + | ``'w'`` | Open existing database for reading and | + | | writing | + +---------+-------------------------------------------+ + | ``'c'`` | Open database for reading and writing, | + | | creating it if it doesn't exist | + +---------+-------------------------------------------+ + | ``'n'`` | Always create a new, empty database, open | + | | for reading and writing | + +---------+-------------------------------------------+ + + The following additional characters may be appended to the flag to control + how the database is opened: + + +---------+--------------------------------------------+ + | Value | Meaning | + +=========+============================================+ + | ``'f'`` | Open the database in fast mode. Writes | + | | to the database will not be synchronized. | + +---------+--------------------------------------------+ + | ``'s'`` | Synchronized mode. This will cause changes | + | | to the database to be immediately written | + | | to the file. | + +---------+--------------------------------------------+ + | ``'u'`` | Do not lock database. | + +---------+--------------------------------------------+ + + Not all flags are valid for all versions of ``gdbm``. The module constant + :const:`open_flags` is a string of supported flag characters. The exception + :exc:`error` is raised if an invalid flag is specified. + + The optional *mode* argument is the Unix mode of the file, used only when the + database has to be created. It defaults to octal ``0666``. + +In addition to the dictionary-like methods, ``gdbm`` objects have the following +methods: + + +.. function:: firstkey() + + It's possible to loop over every key in the database using this method and the + :meth:`nextkey` method. The traversal is ordered by ``gdbm``'s internal hash + values, and won't be sorted by the key values. This method returns the starting + key. + + +.. function:: nextkey(key) + + Returns the key that follows *key* in the traversal. The following code prints + every key in the database ``db``, without having to create a list in memory that + contains them all:: + + k = db.firstkey() + while k != None: + print k + k = db.nextkey(k) + + +.. function:: reorganize() + + If you have carried out a lot of deletions and would like to shrink the space + used by the ``gdbm`` file, this routine will reorganize the database. ``gdbm`` + will not shorten the length of a database file except by using this + reorganization; otherwise, deleted file space will be kept and reused as new + (key, value) pairs are added. + + +.. function:: sync() + + When the database has been opened in fast mode, this method forces any + unwritten data to be written to the disk. + + +.. seealso:: + + Module :mod:`anydbm` + Generic interface to ``dbm``\ -style databases. + + Module :mod:`whichdb` + Utility module used to determine the type of an existing database. + diff --git a/Doc/library/gensuitemodule.rst b/Doc/library/gensuitemodule.rst new file mode 100644 index 0000000..3fc5254 --- /dev/null +++ b/Doc/library/gensuitemodule.rst @@ -0,0 +1,63 @@ + +:mod:`gensuitemodule` --- Generate OSA stub packages +==================================================== + +.. module:: gensuitemodule + :platform: Mac + :synopsis: Create a stub package from an OSA dictionary +.. sectionauthor:: Jack Jansen + + +.. % \moduleauthor{Jack Jansen?}{email} + +The :mod:`gensuitemodule` module creates a Python package implementing stub code +for the AppleScript suites that are implemented by a specific application, +according to its AppleScript dictionary. + +It is usually invoked by the user through the :program:`PythonIDE`, but it can +also be run as a script from the command line (pass :option:`--help` for help on +the options) or imported from Python code. For an example of its use see +:file:`Mac/scripts/genallsuites.py` in a source distribution, which generates +the stub packages that are included in the standard library. + +It defines the following public functions: + + +.. function:: is_scriptable(application) + + Returns true if ``application``, which should be passed as a pathname, appears + to be scriptable. Take the return value with a grain of salt: :program:`Internet + Explorer` appears not to be scriptable but definitely is. + + +.. function:: processfile(application[, output, basepkgname, edit_modnames, creatorsignature, dump, verbose]) + + Create a stub package for ``application``, which should be passed as a full + pathname. For a :file:`.app` bundle this is the pathname to the bundle, not to + the executable inside the bundle; for an unbundled CFM application you pass the + filename of the application binary. + + This function asks the application for its OSA terminology resources, decodes + these resources and uses the resultant data to create the Python code for the + package implementing the client stubs. + + ``output`` is the pathname where the resulting package is stored, if not + specified a standard "save file as" dialog is presented to the user. + ``basepkgname`` is the base package on which this package will build, and + defaults to :mod:`StdSuites`. Only when generating :mod:`StdSuites` itself do + you need to specify this. ``edit_modnames`` is a dictionary that can be used to + change modulenames that are too ugly after name mangling. ``creator_signature`` + can be used to override the 4-char creator code, which is normally obtained from + the :file:`PkgInfo` file in the package or from the CFM file creator signature. + When ``dump`` is given it should refer to a file object, and ``processfile`` + will stop after decoding the resources and dump the Python representation of the + terminology resources to this file. ``verbose`` should also be a file object, + and specifying it will cause ``processfile`` to tell you what it is doing. + + +.. function:: processfile_fromresource(application[, output, basepkgname, edit_modnames, creatorsignature, dump, verbose]) + + This function does the same as ``processfile``, except that it uses a different + method to get the terminology resources. It opens ``application`` as a resource + file and reads all ``"aete"`` and ``"aeut"`` resources from this file. + diff --git a/Doc/library/getopt.rst b/Doc/library/getopt.rst new file mode 100644 index 0000000..0d9641d --- /dev/null +++ b/Doc/library/getopt.rst @@ -0,0 +1,147 @@ + +:mod:`getopt` --- Parser for command line options +================================================= + +.. module:: getopt + :synopsis: Portable parser for command line options; support both short and long option + names. + + +This module helps scripts to parse the command line arguments in ``sys.argv``. +It supports the same conventions as the Unix :cfunc:`getopt` function (including +the special meanings of arguments of the form '``-``' and '``-``\ ``-``'). Long +options similar to those supported by GNU software may be used as well via an +optional third argument. This module provides a single function and an +exception: + +.. % That's to fool latex2html into leaving the two hyphens alone! + + +.. function:: getopt(args, options[, long_options]) + + Parses command line options and parameter list. *args* is the argument list to + be parsed, without the leading reference to the running program. Typically, this + means ``sys.argv[1:]``. *options* is the string of option letters that the + script wants to recognize, with options that require an argument followed by a + colon (``':'``; i.e., the same format that Unix :cfunc:`getopt` uses). + + .. note:: + + Unlike GNU :cfunc:`getopt`, after a non-option argument, all further arguments + are considered also non-options. This is similar to the way non-GNU Unix systems + work. + + *long_options*, if specified, must be a list of strings with the names of the + long options which should be supported. The leading ``'-``\ ``-'`` characters + should not be included in the option name. Long options which require an + argument should be followed by an equal sign (``'='``). To accept only long + options, *options* should be an empty string. Long options on the command line + can be recognized so long as they provide a prefix of the option name that + matches exactly one of the accepted options. For example, if *long_options* is + ``['foo', 'frob']``, the option :option:`--fo` will match as :option:`--foo`, + but :option:`--f` will not match uniquely, so :exc:`GetoptError` will be raised. + + The return value consists of two elements: the first is a list of ``(option, + value)`` pairs; the second is the list of program arguments left after the + option list was stripped (this is a trailing slice of *args*). Each + option-and-value pair returned has the option as its first element, prefixed + with a hyphen for short options (e.g., ``'-x'``) or two hyphens for long + options (e.g., ``'-``\ ``-long-option'``), and the option argument as its + second element, or an empty string if the option has no argument. The + options occur in the list in the same order in which they were found, thus + allowing multiple occurrences. Long and short options may be mixed. + + +.. function:: gnu_getopt(args, options[, long_options]) + + This function works like :func:`getopt`, except that GNU style scanning mode is + used by default. This means that option and non-option arguments may be + intermixed. The :func:`getopt` function stops processing options as soon as a + non-option argument is encountered. + + If the first character of the option string is '+', or if the environment + variable POSIXLY_CORRECT is set, then option processing stops as soon as a + non-option argument is encountered. + + .. versionadded:: 2.3 + + +.. exception:: GetoptError + + This is raised when an unrecognized option is found in the argument list or when + an option requiring an argument is given none. The argument to the exception is + a string indicating the cause of the error. For long options, an argument given + to an option which does not require one will also cause this exception to be + raised. The attributes :attr:`msg` and :attr:`opt` give the error message and + related option; if there is no specific option to which the exception relates, + :attr:`opt` is an empty string. + + .. versionchanged:: 1.6 + Introduced :exc:`GetoptError` as a synonym for :exc:`error`. + + +.. exception:: error + + Alias for :exc:`GetoptError`; for backward compatibility. + +An example using only Unix style options:: + + >>> import getopt + >>> args = '-a -b -cfoo -d bar a1 a2'.split() + >>> args + ['-a', '-b', '-cfoo', '-d', 'bar', 'a1', 'a2'] + >>> optlist, args = getopt.getopt(args, 'abc:d:') + >>> optlist + [('-a', ''), ('-b', ''), ('-c', 'foo'), ('-d', 'bar')] + >>> args + ['a1', 'a2'] + +Using long option names is equally easy:: + + >>> s = '--condition=foo --testing --output-file abc.def -x a1 a2' + >>> args = s.split() + >>> args + ['--condition=foo', '--testing', '--output-file', 'abc.def', '-x', 'a1', 'a2'] + >>> optlist, args = getopt.getopt(args, 'x', [ + ... 'condition=', 'output-file=', 'testing']) + >>> optlist + [('--condition', 'foo'), ('--testing', ''), ('--output-file', 'abc.def'), ('-x', + '')] + >>> args + ['a1', 'a2'] + +In a script, typical usage is something like this:: + + import getopt, sys + + def main(): + try: + opts, args = getopt.getopt(sys.argv[1:], "ho:v", ["help", "output="]) + except getopt.GetoptError as err: + # print help information and exit: + print str(err) # will print something like "option -a not recognized" + usage() + sys.exit(2) + output = None + verbose = False + for o, a in opts: + if o == "-v": + verbose = True + elif o in ("-h", "--help"): + usage() + sys.exit() + elif o in ("-o", "--output"): + output = a + else: + assert False, "unhandled option" + # ... + + if __name__ == "__main__": + main() + + +.. seealso:: + + Module :mod:`optparse` + More object-oriented command line option parsing. + diff --git a/Doc/library/getpass.rst b/Doc/library/getpass.rst new file mode 100644 index 0000000..45c6e53 --- /dev/null +++ b/Doc/library/getpass.rst @@ -0,0 +1,38 @@ + +:mod:`getpass` --- Portable password input +========================================== + +.. module:: getpass + :synopsis: Portable reading of passwords and retrieval of the userid. +.. moduleauthor:: Piers Lauder +.. sectionauthor:: Fred L. Drake, Jr. + + +.. % Windows (& Mac?) support by Guido van Rossum. + +The :mod:`getpass` module provides two functions: + + +.. function:: getpass([prompt[, stream]]) + + Prompt the user for a password without echoing. The user is prompted using the + string *prompt*, which defaults to ``'Password: '``. On Unix, the prompt is + written to the file-like object *stream*, which defaults to ``sys.stdout`` (this + argument is ignored on Windows). + + Availability: Macintosh, Unix, Windows. + + .. versionchanged:: 2.5 + The *stream* parameter was added. + + +.. function:: getuser() + + Return the "login name" of the user. Availability: Unix, Windows. + + This function checks the environment variables :envvar:`LOGNAME`, + :envvar:`USER`, :envvar:`LNAME` and :envvar:`USERNAME`, in order, and returns + the value of the first one which is set to a non-empty string. If none are set, + the login name from the password database is returned on systems which support + the :mod:`pwd` module, otherwise, an exception is raised. + diff --git a/Doc/library/gettext.rst b/Doc/library/gettext.rst new file mode 100644 index 0000000..51628e6 --- /dev/null +++ b/Doc/library/gettext.rst @@ -0,0 +1,765 @@ + +:mod:`gettext` --- Multilingual internationalization services +============================================================= + +.. module:: gettext + :synopsis: Multilingual internationalization services. +.. moduleauthor:: Barry A. Warsaw +.. sectionauthor:: Barry A. Warsaw + + +The :mod:`gettext` module provides internationalization (I18N) and localization +(L10N) services for your Python modules and applications. It supports both the +GNU ``gettext`` message catalog API and a higher level, class-based API that may +be more appropriate for Python files. The interface described below allows you +to write your module and application messages in one natural language, and +provide a catalog of translated messages for running under different natural +languages. + +Some hints on localizing your Python modules and applications are also given. + + +GNU :program:`gettext` API +-------------------------- + +The :mod:`gettext` module defines the following API, which is very similar to +the GNU :program:`gettext` API. If you use this API you will affect the +translation of your entire application globally. Often this is what you want if +your application is monolingual, with the choice of language dependent on the +locale of your user. If you are localizing a Python module, or if your +application needs to switch languages on the fly, you probably want to use the +class-based API instead. + + +.. function:: bindtextdomain(domain[, localedir]) + + Bind the *domain* to the locale directory *localedir*. More concretely, + :mod:`gettext` will look for binary :file:`.mo` files for the given domain using + the path (on Unix): :file:`localedir/language/LC_MESSAGES/domain.mo`, where + *languages* is searched for in the environment variables :envvar:`LANGUAGE`, + :envvar:`LC_ALL`, :envvar:`LC_MESSAGES`, and :envvar:`LANG` respectively. + + If *localedir* is omitted or ``None``, then the current binding for *domain* is + returned. [#]_ + + +.. function:: bind_textdomain_codeset(domain[, codeset]) + + Bind the *domain* to *codeset*, changing the encoding of strings returned by the + :func:`gettext` family of functions. If *codeset* is omitted, then the current + binding is returned. + + .. versionadded:: 2.4 + + +.. function:: textdomain([domain]) + + Change or query the current global domain. If *domain* is ``None``, then the + current global domain is returned, otherwise the global domain is set to + *domain*, which is returned. + + +.. function:: gettext(message) + + Return the localized translation of *message*, based on the current global + domain, language, and locale directory. This function is usually aliased as + :func:`_` in the local namespace (see examples below). + + +.. function:: lgettext(message) + + Equivalent to :func:`gettext`, but the translation is returned in the preferred + system encoding, if no other encoding was explicitly set with + :func:`bind_textdomain_codeset`. + + .. versionadded:: 2.4 + + +.. function:: dgettext(domain, message) + + Like :func:`gettext`, but look the message up in the specified *domain*. + + +.. function:: ldgettext(domain, message) + + Equivalent to :func:`dgettext`, but the translation is returned in the preferred + system encoding, if no other encoding was explicitly set with + :func:`bind_textdomain_codeset`. + + .. versionadded:: 2.4 + + +.. function:: ngettext(singular, plural, n) + + Like :func:`gettext`, but consider plural forms. If a translation is found, + apply the plural formula to *n*, and return the resulting message (some + languages have more than two plural forms). If no translation is found, return + *singular* if *n* is 1; return *plural* otherwise. + + The Plural formula is taken from the catalog header. It is a C or Python + expression that has a free variable *n*; the expression evaluates to the index + of the plural in the catalog. See the GNU gettext documentation for the precise + syntax to be used in :file:`.po` files and the formulas for a variety of + languages. + + .. versionadded:: 2.3 + + +.. function:: lngettext(singular, plural, n) + + Equivalent to :func:`ngettext`, but the translation is returned in the preferred + system encoding, if no other encoding was explicitly set with + :func:`bind_textdomain_codeset`. + + .. versionadded:: 2.4 + + +.. function:: dngettext(domain, singular, plural, n) + + Like :func:`ngettext`, but look the message up in the specified *domain*. + + .. versionadded:: 2.3 + + +.. function:: ldngettext(domain, singular, plural, n) + + Equivalent to :func:`dngettext`, but the translation is returned in the + preferred system encoding, if no other encoding was explicitly set with + :func:`bind_textdomain_codeset`. + + .. versionadded:: 2.4 + +Note that GNU :program:`gettext` also defines a :func:`dcgettext` method, but +this was deemed not useful and so it is currently unimplemented. + +Here's an example of typical usage for this API:: + + import gettext + gettext.bindtextdomain('myapplication', '/path/to/my/language/directory') + gettext.textdomain('myapplication') + _ = gettext.gettext + # ... + print _('This is a translatable string.') + + +Class-based API +--------------- + +The class-based API of the :mod:`gettext` module gives you more flexibility and +greater convenience than the GNU :program:`gettext` API. It is the recommended +way of localizing your Python applications and modules. :mod:`gettext` defines +a "translations" class which implements the parsing of GNU :file:`.mo` format +files, and has methods for returning either standard 8-bit strings or Unicode +strings. Instances of this "translations" class can also install themselves in +the built-in namespace as the function :func:`_`. + + +.. function:: find(domain[, localedir[, languages[, all]]]) + + This function implements the standard :file:`.mo` file search algorithm. It + takes a *domain*, identical to what :func:`textdomain` takes. Optional + *localedir* is as in :func:`bindtextdomain` Optional *languages* is a list of + strings, where each string is a language code. + + If *localedir* is not given, then the default system locale directory is used. + [#]_ If *languages* is not given, then the following environment variables are + searched: :envvar:`LANGUAGE`, :envvar:`LC_ALL`, :envvar:`LC_MESSAGES`, and + :envvar:`LANG`. The first one returning a non-empty value is used for the + *languages* variable. The environment variables should contain a colon separated + list of languages, which will be split on the colon to produce the expected list + of language code strings. + + :func:`find` then expands and normalizes the languages, and then iterates + through them, searching for an existing file built of these components: + + :file:`localedir/language/LC_MESSAGES/domain.mo` + + The first such file name that exists is returned by :func:`find`. If no such + file is found, then ``None`` is returned. If *all* is given, it returns a list + of all file names, in the order in which they appear in the languages list or + the environment variables. + + +.. function:: translation(domain[, localedir[, languages[, class_[, fallback[, codeset]]]]]) + + Return a :class:`Translations` instance based on the *domain*, *localedir*, and + *languages*, which are first passed to :func:`find` to get a list of the + associated :file:`.mo` file paths. Instances with identical :file:`.mo` file + names are cached. The actual class instantiated is either *class_* if provided, + otherwise :class:`GNUTranslations`. The class's constructor must take a single + file object argument. If provided, *codeset* will change the charset used to + encode translated strings. + + If multiple files are found, later files are used as fallbacks for earlier ones. + To allow setting the fallback, :func:`copy.copy` is used to clone each + translation object from the cache; the actual instance data is still shared with + the cache. + + If no :file:`.mo` file is found, this function raises :exc:`IOError` if + *fallback* is false (which is the default), and returns a + :class:`NullTranslations` instance if *fallback* is true. + + .. versionchanged:: 2.4 + Added the *codeset* parameter. + + +.. function:: install(domain[, localedir[, unicode [, codeset[, names]]]]) + + This installs the function :func:`_` in Python's builtin namespace, based on + *domain*, *localedir*, and *codeset* which are passed to the function + :func:`translation`. The *unicode* flag is passed to the resulting translation + object's :meth:`install` method. + + For the *names* parameter, please see the description of the translation + object's :meth:`install` method. + + As seen below, you usually mark the strings in your application that are + candidates for translation, by wrapping them in a call to the :func:`_` + function, like this:: + + print _('This string will be translated.') + + For convenience, you want the :func:`_` function to be installed in Python's + builtin namespace, so it is easily accessible in all modules of your + application. + + .. versionchanged:: 2.4 + Added the *codeset* parameter. + + .. versionchanged:: 2.5 + Added the *names* parameter. + + +The :class:`NullTranslations` class +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +Translation classes are what actually implement the translation of original +source file message strings to translated message strings. The base class used +by all translation classes is :class:`NullTranslations`; this provides the basic +interface you can use to write your own specialized translation classes. Here +are the methods of :class:`NullTranslations`: + + +.. method:: NullTranslations.__init__([fp]) + + Takes an optional file object *fp*, which is ignored by the base class. + Initializes "protected" instance variables *_info* and *_charset* which are set + by derived classes, as well as *_fallback*, which is set through + :meth:`add_fallback`. It then calls ``self._parse(fp)`` if *fp* is not + ``None``. + + +.. method:: NullTranslations._parse(fp) + + No-op'd in the base class, this method takes file object *fp*, and reads the + data from the file, initializing its message catalog. If you have an + unsupported message catalog file format, you should override this method to + parse your format. + + +.. method:: NullTranslations.add_fallback(fallback) + + Add *fallback* as the fallback object for the current translation object. A + translation object should consult the fallback if it cannot provide a + translation for a given message. + + +.. method:: NullTranslations.gettext(message) + + If a fallback has been set, forward :meth:`gettext` to the fallback. Otherwise, + return the translated message. Overridden in derived classes. + + +.. method:: NullTranslations.lgettext(message) + + If a fallback has been set, forward :meth:`lgettext` to the fallback. Otherwise, + return the translated message. Overridden in derived classes. + + .. versionadded:: 2.4 + + +.. method:: NullTranslations.ugettext(message) + + If a fallback has been set, forward :meth:`ugettext` to the fallback. Otherwise, + return the translated message as a Unicode string. Overridden in derived + classes. + + +.. method:: NullTranslations.ngettext(singular, plural, n) + + If a fallback has been set, forward :meth:`ngettext` to the fallback. Otherwise, + return the translated message. Overridden in derived classes. + + .. versionadded:: 2.3 + + +.. method:: NullTranslations.lngettext(singular, plural, n) + + If a fallback has been set, forward :meth:`ngettext` to the fallback. Otherwise, + return the translated message. Overridden in derived classes. + + .. versionadded:: 2.4 + + +.. method:: NullTranslations.ungettext(singular, plural, n) + + If a fallback has been set, forward :meth:`ungettext` to the fallback. + Otherwise, return the translated message as a Unicode string. Overridden in + derived classes. + + .. versionadded:: 2.3 + + +.. method:: NullTranslations.info() + + Return the "protected" :attr:`_info` variable. + + +.. method:: NullTranslations.charset() + + Return the "protected" :attr:`_charset` variable. + + +.. method:: NullTranslations.output_charset() + + Return the "protected" :attr:`_output_charset` variable, which defines the + encoding used to return translated messages. + + .. versionadded:: 2.4 + + +.. method:: NullTranslations.set_output_charset(charset) + + Change the "protected" :attr:`_output_charset` variable, which defines the + encoding used to return translated messages. + + .. versionadded:: 2.4 + + +.. method:: NullTranslations.install([unicode [, names]]) + + If the *unicode* flag is false, this method installs :meth:`self.gettext` into + the built-in namespace, binding it to ``_``. If *unicode* is true, it binds + :meth:`self.ugettext` instead. By default, *unicode* is false. + + If the *names* parameter is given, it must be a sequence containing the names of + functions you want to install in the builtin namespace in addition to :func:`_`. + Supported names are ``'gettext'`` (bound to :meth:`self.gettext` or + :meth:`self.ugettext` according to the *unicode* flag), ``'ngettext'`` (bound to + :meth:`self.ngettext` or :meth:`self.ungettext` according to the *unicode* + flag), ``'lgettext'`` and ``'lngettext'``. + + Note that this is only one way, albeit the most convenient way, to make the + :func:`_` function available to your application. Because it affects the entire + application globally, and specifically the built-in namespace, localized modules + should never install :func:`_`. Instead, they should use this code to make + :func:`_` available to their module:: + + import gettext + t = gettext.translation('mymodule', ...) + _ = t.gettext + + This puts :func:`_` only in the module's global namespace and so only affects + calls within this module. + + .. versionchanged:: 2.5 + Added the *names* parameter. + + +The :class:`GNUTranslations` class +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The :mod:`gettext` module provides one additional class derived from +:class:`NullTranslations`: :class:`GNUTranslations`. This class overrides +:meth:`_parse` to enable reading GNU :program:`gettext` format :file:`.mo` files +in both big-endian and little-endian format. It also coerces both message ids +and message strings to Unicode. + +:class:`GNUTranslations` parses optional meta-data out of the translation +catalog. It is convention with GNU :program:`gettext` to include meta-data as +the translation for the empty string. This meta-data is in :rfc:`822`\ -style +``key: value`` pairs, and should contain the ``Project-Id-Version`` key. If the +key ``Content-Type`` is found, then the ``charset`` property is used to +initialize the "protected" :attr:`_charset` instance variable, defaulting to +``None`` if not found. If the charset encoding is specified, then all message +ids and message strings read from the catalog are converted to Unicode using +this encoding. The :meth:`ugettext` method always returns a Unicode, while the +:meth:`gettext` returns an encoded 8-bit string. For the message id arguments +of both methods, either Unicode strings or 8-bit strings containing only +US-ASCII characters are acceptable. Note that the Unicode version of the +methods (i.e. :meth:`ugettext` and :meth:`ungettext`) are the recommended +interface to use for internationalized Python programs. + +The entire set of key/value pairs are placed into a dictionary and set as the +"protected" :attr:`_info` instance variable. + +If the :file:`.mo` file's magic number is invalid, or if other problems occur +while reading the file, instantiating a :class:`GNUTranslations` class can raise +:exc:`IOError`. + +The following methods are overridden from the base class implementation: + + +.. method:: GNUTranslations.gettext(message) + + Look up the *message* id in the catalog and return the corresponding message + string, as an 8-bit string encoded with the catalog's charset encoding, if + known. If there is no entry in the catalog for the *message* id, and a fallback + has been set, the look up is forwarded to the fallback's :meth:`gettext` method. + Otherwise, the *message* id is returned. + + +.. method:: GNUTranslations.lgettext(message) + + Equivalent to :meth:`gettext`, but the translation is returned in the preferred + system encoding, if no other encoding was explicitly set with + :meth:`set_output_charset`. + + .. versionadded:: 2.4 + + +.. method:: GNUTranslations.ugettext(message) + + Look up the *message* id in the catalog and return the corresponding message + string, as a Unicode string. If there is no entry in the catalog for the + *message* id, and a fallback has been set, the look up is forwarded to the + fallback's :meth:`ugettext` method. Otherwise, the *message* id is returned. + + +.. method:: GNUTranslations.ngettext(singular, plural, n) + + Do a plural-forms lookup of a message id. *singular* is used as the message id + for purposes of lookup in the catalog, while *n* is used to determine which + plural form to use. The returned message string is an 8-bit string encoded with + the catalog's charset encoding, if known. + + If the message id is not found in the catalog, and a fallback is specified, the + request is forwarded to the fallback's :meth:`ngettext` method. Otherwise, when + *n* is 1 *singular* is returned, and *plural* is returned in all other cases. + + .. versionadded:: 2.3 + + +.. method:: GNUTranslations.lngettext(singular, plural, n) + + Equivalent to :meth:`gettext`, but the translation is returned in the preferred + system encoding, if no other encoding was explicitly set with + :meth:`set_output_charset`. + + .. versionadded:: 2.4 + + +.. method:: GNUTranslations.ungettext(singular, plural, n) + + Do a plural-forms lookup of a message id. *singular* is used as the message id + for purposes of lookup in the catalog, while *n* is used to determine which + plural form to use. The returned message string is a Unicode string. + + If the message id is not found in the catalog, and a fallback is specified, the + request is forwarded to the fallback's :meth:`ungettext` method. Otherwise, + when *n* is 1 *singular* is returned, and *plural* is returned in all other + cases. + + Here is an example:: + + n = len(os.listdir('.')) + cat = GNUTranslations(somefile) + message = cat.ungettext( + 'There is %(num)d file in this directory', + 'There are %(num)d files in this directory', + n) % {'num': n} + + .. versionadded:: 2.3 + + +Solaris message catalog support +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +The Solaris operating system defines its own binary :file:`.mo` file format, but +since no documentation can be found on this format, it is not supported at this +time. + + +The Catalog constructor +^^^^^^^^^^^^^^^^^^^^^^^ + +.. index:: single: GNOME + +GNOME uses a version of the :mod:`gettext` module by James Henstridge, but this +version has a slightly different API. Its documented usage was:: + + import gettext + cat = gettext.Catalog(domain, localedir) + _ = cat.gettext + print _('hello world') + +For compatibility with this older module, the function :func:`Catalog` is an +alias for the :func:`translation` function described above. + +One difference between this module and Henstridge's: his catalog objects +supported access through a mapping API, but this appears to be unused and so is +not currently supported. + + +Internationalizing your programs and modules +-------------------------------------------- + +Internationalization (I18N) refers to the operation by which a program is made +aware of multiple languages. Localization (L10N) refers to the adaptation of +your program, once internationalized, to the local language and cultural habits. +In order to provide multilingual messages for your Python programs, you need to +take the following steps: + +#. prepare your program or module by specially marking translatable strings + +#. run a suite of tools over your marked files to generate raw messages catalogs + +#. create language specific translations of the message catalogs + +#. use the :mod:`gettext` module so that message strings are properly translated + +In order to prepare your code for I18N, you need to look at all the strings in +your files. Any string that needs to be translated should be marked by wrapping +it in ``_('...')`` --- that is, a call to the function :func:`_`. For example:: + + filename = 'mylog.txt' + message = _('writing a log message') + fp = open(filename, 'w') + fp.write(message) + fp.close() + +In this example, the string ``'writing a log message'`` is marked as a candidate +for translation, while the strings ``'mylog.txt'`` and ``'w'`` are not. + +The Python distribution comes with two tools which help you generate the message +catalogs once you've prepared your source code. These may or may not be +available from a binary distribution, but they can be found in a source +distribution, in the :file:`Tools/i18n` directory. + +The :program:`pygettext` [#]_ program scans all your Python source code looking +for the strings you previously marked as translatable. It is similar to the GNU +:program:`gettext` program except that it understands all the intricacies of +Python source code, but knows nothing about C or C++ source code. You don't +need GNU ``gettext`` unless you're also going to be translating C code (such as +C extension modules). + +:program:`pygettext` generates textual Uniforum-style human readable message +catalog :file:`.pot` files, essentially structured human readable files which +contain every marked string in the source code, along with a placeholder for the +translation strings. :program:`pygettext` is a command line script that supports +a similar command line interface as :program:`xgettext`; for details on its use, +run:: + + pygettext.py --help + +Copies of these :file:`.pot` files are then handed over to the individual human +translators who write language-specific versions for every supported natural +language. They send you back the filled in language-specific versions as a +:file:`.po` file. Using the :program:`msgfmt.py` [#]_ program (in the +:file:`Tools/i18n` directory), you take the :file:`.po` files from your +translators and generate the machine-readable :file:`.mo` binary catalog files. +The :file:`.mo` files are what the :mod:`gettext` module uses for the actual +translation processing during run-time. + +How you use the :mod:`gettext` module in your code depends on whether you are +internationalizing a single module or your entire application. The next two +sections will discuss each case. + + +Localizing your module +^^^^^^^^^^^^^^^^^^^^^^ + +If you are localizing your module, you must take care not to make global +changes, e.g. to the built-in namespace. You should not use the GNU ``gettext`` +API but instead the class-based API. + +Let's say your module is called "spam" and the module's various natural language +translation :file:`.mo` files reside in :file:`/usr/share/locale` in GNU +:program:`gettext` format. Here's what you would put at the top of your +module:: + + import gettext + t = gettext.translation('spam', '/usr/share/locale') + _ = t.lgettext + +If your translators were providing you with Unicode strings in their :file:`.po` +files, you'd instead do:: + + import gettext + t = gettext.translation('spam', '/usr/share/locale') + _ = t.ugettext + + +Localizing your application +^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +If you are localizing your application, you can install the :func:`_` function +globally into the built-in namespace, usually in the main driver file of your +application. This will let all your application-specific files just use +``_('...')`` without having to explicitly install it in each file. + +In the simple case then, you need only add the following bit of code to the main +driver file of your application:: + + import gettext + gettext.install('myapplication') + +If you need to set the locale directory or the *unicode* flag, you can pass +these into the :func:`install` function:: + + import gettext + gettext.install('myapplication', '/usr/share/locale', unicode=1) + + +Changing languages on the fly +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +If your program needs to support many languages at the same time, you may want +to create multiple translation instances and then switch between them +explicitly, like so:: + + import gettext + + lang1 = gettext.translation('myapplication', languages=['en']) + lang2 = gettext.translation('myapplication', languages=['fr']) + lang3 = gettext.translation('myapplication', languages=['de']) + + # start by using language1 + lang1.install() + + # ... time goes by, user selects language 2 + lang2.install() + + # ... more time goes by, user selects language 3 + lang3.install() + + +Deferred translations +^^^^^^^^^^^^^^^^^^^^^ + +In most coding situations, strings are translated where they are coded. +Occasionally however, you need to mark strings for translation, but defer actual +translation until later. A classic example is:: + + animals = ['mollusk', + 'albatross', + 'rat', + 'penguin', + 'python', + ] + # ... + for a in animals: + print a + +Here, you want to mark the strings in the ``animals`` list as being +translatable, but you don't actually want to translate them until they are +printed. + +Here is one way you can handle this situation:: + + def _(message): return message + + animals = [_('mollusk'), + _('albatross'), + _('rat'), + _('penguin'), + _('python'), + ] + + del _ + + # ... + for a in animals: + print _(a) + +This works because the dummy definition of :func:`_` simply returns the string +unchanged. And this dummy definition will temporarily override any definition +of :func:`_` in the built-in namespace (until the :keyword:`del` command). Take +care, though if you have a previous definition of :func:`_` in the local +namespace. + +Note that the second use of :func:`_` will not identify "a" as being +translatable to the :program:`pygettext` program, since it is not a string. + +Another way to handle this is with the following example:: + + def N_(message): return message + + animals = [N_('mollusk'), + N_('albatross'), + N_('rat'), + N_('penguin'), + N_('python'), + ] + + # ... + for a in animals: + print _(a) + +In this case, you are marking translatable strings with the function :func:`N_`, +[#]_ which won't conflict with any definition of :func:`_`. However, you will +need to teach your message extraction program to look for translatable strings +marked with :func:`N_`. :program:`pygettext` and :program:`xpot` both support +this through the use of command line switches. + + +:func:`gettext` vs. :func:`lgettext` +^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +In Python 2.4 the :func:`lgettext` family of functions were introduced. The +intention of these functions is to provide an alternative which is more +compliant with the current implementation of GNU gettext. Unlike +:func:`gettext`, which returns strings encoded with the same codeset used in the +translation file, :func:`lgettext` will return strings encoded with the +preferred system encoding, as returned by :func:`locale.getpreferredencoding`. +Also notice that Python 2.4 introduces new functions to explicitly choose the +codeset used in translated strings. If a codeset is explicitly set, even +:func:`lgettext` will return translated strings in the requested codeset, as +would be expected in the GNU gettext implementation. + + +Acknowledgements +---------------- + +The following people contributed code, feedback, design suggestions, previous +implementations, and valuable experience to the creation of this module: + +* Peter Funk + +* James Henstridge + +* Juan David Ibáñez Palomar + +* Marc-André Lemburg + +* Martin von Löwis + +* François Pinard + +* Barry Warsaw + +* Gustavo Niemeyer + +.. rubric:: Footnotes + +.. [#] The default locale directory is system dependent; for example, on RedHat Linux + it is :file:`/usr/share/locale`, but on Solaris it is :file:`/usr/lib/locale`. + The :mod:`gettext` module does not try to support these system dependent + defaults; instead its default is :file:`sys.prefix/share/locale`. For this + reason, it is always best to call :func:`bindtextdomain` with an explicit + absolute path at the start of your application. + +.. [#] See the footnote for :func:`bindtextdomain` above. + +.. [#] François Pinard has written a program called :program:`xpot` which does a + similar job. It is available as part of his :program:`po-utils` package at http + ://po-utils.progiciels-bpi.ca/. + +.. [#] :program:`msgfmt.py` is binary compatible with GNU :program:`msgfmt` except that + it provides a simpler, all-Python implementation. With this and + :program:`pygettext.py`, you generally won't need to install the GNU + :program:`gettext` package to internationalize your Python applications. + +.. [#] The choice of :func:`N_` here is totally arbitrary; it could have just as easily + been :func:`MarkThisStringForTranslation`. + diff --git a/Doc/library/glob.rst b/Doc/library/glob.rst new file mode 100644 index 0000000..80bdac2 --- /dev/null +++ b/Doc/library/glob.rst @@ -0,0 +1,54 @@ + +:mod:`glob` --- Unix style pathname pattern expansion +===================================================== + +.. module:: glob + :synopsis: Unix shell style pathname pattern expansion. + + +.. index:: single: filenames; pathname expansion + +The :mod:`glob` module finds all the pathnames matching a specified pattern +according to the rules used by the Unix shell. No tilde expansion is done, but +``*``, ``?``, and character ranges expressed with ``[]`` will be correctly +matched. This is done by using the :func:`os.listdir` and +:func:`fnmatch.fnmatch` functions in concert, and not by actually invoking a +subshell. (For tilde and shell variable expansion, use +:func:`os.path.expanduser` and :func:`os.path.expandvars`.) + + +.. function:: glob(pathname) + + Return a possibly-empty list of path names that match *pathname*, which must be + a string containing a path specification. *pathname* can be either absolute + (like :file:`/usr/src/Python-1.5/Makefile`) or relative (like + :file:`../../Tools/\*/\*.gif`), and can contain shell-style wildcards. Broken + symlinks are included in the results (as in the shell). + + +.. function:: iglob(pathname) + + Return an iterator which yields the same values as :func:`glob` without actually + storing them all simultaneously. + + .. versionadded:: 2.5 + +For example, consider a directory containing only the following files: +:file:`1.gif`, :file:`2.txt`, and :file:`card.gif`. :func:`glob` will produce +the following results. Notice how any leading components of the path are +preserved. :: + + >>> import glob + >>> glob.glob('./[0-9].*') + ['./1.gif', './2.txt'] + >>> glob.glob('*.gif') + ['1.gif', 'card.gif'] + >>> glob.glob('?.gif') + ['1.gif'] + + +.. seealso:: + + Module :mod:`fnmatch` + Shell-style filename (not path) expansion + diff --git a/Doc/library/grp.rst b/Doc/library/grp.rst new file mode 100644 index 0000000..a71c308 --- /dev/null +++ b/Doc/library/grp.rst @@ -0,0 +1,63 @@ + +:mod:`grp` --- The group database +================================= + +.. module:: grp + :platform: Unix + :synopsis: The group database (getgrnam() and friends). + + +This module provides access to the Unix group database. It is available on all +Unix versions. + +Group database entries are reported as a tuple-like object, whose attributes +correspond to the members of the ``group`` structure (Attribute field below, see +````): + ++-------+-----------+---------------------------------+ +| Index | Attribute | Meaning | ++=======+===========+=================================+ +| 0 | gr_name | the name of the group | ++-------+-----------+---------------------------------+ +| 1 | gr_passwd | the (encrypted) group password; | +| | | often empty | ++-------+-----------+---------------------------------+ +| 2 | gr_gid | the numerical group ID | ++-------+-----------+---------------------------------+ +| 3 | gr_mem | all the group member's user | +| | | names | ++-------+-----------+---------------------------------+ + +The gid is an integer, name and password are strings, and the member list is a +list of strings. (Note that most users are not explicitly listed as members of +the group they are in according to the password database. Check both databases +to get complete membership information.) + +It defines the following items: + + +.. function:: getgrgid(gid) + + Return the group database entry for the given numeric group ID. :exc:`KeyError` + is raised if the entry asked for cannot be found. + + +.. function:: getgrnam(name) + + Return the group database entry for the given group name. :exc:`KeyError` is + raised if the entry asked for cannot be found. + + +.. function:: getgrall() + + Return a list of all available group entries, in arbitrary order. + + +.. seealso:: + + Module :mod:`pwd` + An interface to the user database, similar to this. + + Module :mod:`spwd` + An interface to the shadow password database, similar to this. + diff --git a/Doc/library/gzip.rst b/Doc/library/gzip.rst new file mode 100644 index 0000000..5978031 --- /dev/null +++ b/Doc/library/gzip.rst @@ -0,0 +1,68 @@ + +:mod:`gzip` --- Support for :program:`gzip` files +================================================= + +.. module:: gzip + :synopsis: Interfaces for gzip compression and decompression using file objects. + + +The data compression provided by the ``zlib`` module is compatible with that +used by the GNU compression program :program:`gzip`. Accordingly, the +:mod:`gzip` module provides the :class:`GzipFile` class to read and write +:program:`gzip`\ -format files, automatically compressing or decompressing the +data so it looks like an ordinary file object. Note that additional file +formats which can be decompressed by the :program:`gzip` and :program:`gunzip` +programs, such as those produced by :program:`compress` and :program:`pack`, +are not supported by this module. + +The module defines the following items: + + +.. class:: GzipFile([filename[, mode[, compresslevel[, fileobj]]]]) + + Constructor for the :class:`GzipFile` class, which simulates most of the methods + of a file object, with the exception of the :meth:`readinto` and + :meth:`truncate` methods. At least one of *fileobj* and *filename* must be + given a non-trivial value. + + The new class instance is based on *fileobj*, which can be a regular file, a + :class:`StringIO` object, or any other object which simulates a file. It + defaults to ``None``, in which case *filename* is opened to provide a file + object. + + When *fileobj* is not ``None``, the *filename* argument is only used to be + included in the :program:`gzip` file header, which may includes the original + filename of the uncompressed file. It defaults to the filename of *fileobj*, if + discernible; otherwise, it defaults to the empty string, and in this case the + original filename is not included in the header. + + The *mode* argument can be any of ``'r'``, ``'rb'``, ``'a'``, ``'ab'``, ``'w'``, + or ``'wb'``, depending on whether the file will be read or written. The default + is the mode of *fileobj* if discernible; otherwise, the default is ``'rb'``. If + not given, the 'b' flag will be added to the mode to ensure the file is opened + in binary mode for cross-platform portability. + + The *compresslevel* argument is an integer from ``1`` to ``9`` controlling the + level of compression; ``1`` is fastest and produces the least compression, and + ``9`` is slowest and produces the most compression. The default is ``9``. + + Calling a :class:`GzipFile` object's :meth:`close` method does not close + *fileobj*, since you might wish to append more material after the compressed + data. This also allows you to pass a :class:`StringIO` object opened for + writing as *fileobj*, and retrieve the resulting memory buffer using the + :class:`StringIO` object's :meth:`getvalue` method. + + +.. function:: open(filename[, mode[, compresslevel]]) + + This is a shorthand for ``GzipFile(filename,`` ``mode,`` ``compresslevel)``. + The *filename* argument is required; *mode* defaults to ``'rb'`` and + *compresslevel* defaults to ``9``. + + +.. seealso:: + + Module :mod:`zlib` + The basic data compression module needed to support the :program:`gzip` file + format. + diff --git a/Doc/library/hashlib.rst b/Doc/library/hashlib.rst new file mode 100644 index 0000000..f255554 --- /dev/null +++ b/Doc/library/hashlib.rst @@ -0,0 +1,121 @@ + +:mod:`hashlib` --- Secure hashes and message digests +==================================================== + +.. module:: hashlib + :synopsis: Secure hash and message digest algorithms. +.. moduleauthor:: Gregory P. Smith +.. sectionauthor:: Gregory P. Smith + + +.. versionadded:: 2.5 + +.. index:: + single: message digest, MD5 + single: secure hash algorithm, SHA1, SHA224, SHA256, SHA384, SHA512 + +This module implements a common interface to many different secure hash and +message digest algorithms. Included are the FIPS secure hash algorithms SHA1, +SHA224, SHA256, SHA384, and SHA512 (defined in FIPS 180-2) as well as RSA's MD5 +algorithm (defined in Internet :rfc:`1321`). The terms secure hash and message +digest are interchangeable. Older algorithms were called message digests. The +modern term is secure hash. + +.. warning:: + + Some algorithms have known hash collision weaknesses, see the FAQ at the end. + +There is one constructor method named for each type of :dfn:`hash`. All return +a hash object with the same simple interface. For example: use :func:`sha1` to +create a SHA1 hash object. You can now feed this object with arbitrary strings +using the :meth:`update` method. At any point you can ask it for the +:dfn:`digest` of the concatenation of the strings fed to it so far using the +:meth:`digest` or :meth:`hexdigest` methods. + +.. index:: single: OpenSSL + +Constructors for hash algorithms that are always present in this module are +:func:`md5`, :func:`sha1`, :func:`sha224`, :func:`sha256`, :func:`sha384`, and +:func:`sha512`. Additional algorithms may also be available depending upon the +OpenSSL library that Python uses on your platform. + +For example, to obtain the digest of the string ``'Nobody inspects the spammish +repetition'``:: + + >>> import hashlib + >>> m = hashlib.md5() + >>> m.update("Nobody inspects") + >>> m.update(" the spammish repetition") + >>> m.digest() + '\xbbd\x9c\x83\xdd\x1e\xa5\xc9\xd9\xde\xc9\xa1\x8d\xf0\xff\xe9' + +More condensed:: + + >>> hashlib.sha224("Nobody inspects the spammish repetition").hexdigest() + 'a4337bc45a8fc544c03f52dc550cd6e1e87021bc896588bd79e901e2' + +A generic :func:`new` constructor that takes the string name of the desired +algorithm as its first parameter also exists to allow access to the above listed +hashes as well as any other algorithms that your OpenSSL library may offer. The +named constructors are much faster than :func:`new` and should be preferred. + +Using :func:`new` with an algorithm provided by OpenSSL:: + + >>> h = hashlib.new('ripemd160') + >>> h.update("Nobody inspects the spammish repetition") + >>> h.hexdigest() + 'cc4a5ce1b3df48aec5d22d1f16b894a0b894eccc' + +The following values are provided as constant attributes of the hash objects +returned by the constructors: + + +.. data:: digest_size + + The size of the resulting digest in bytes. + +A hash object has the following methods: + + +.. method:: hash.update(arg) + + Update the hash object with the string *arg*. Repeated calls are equivalent to + a single call with the concatenation of all the arguments: ``m.update(a); + m.update(b)`` is equivalent to ``m.update(a+b)``. + + +.. method:: hash.digest() + + Return the digest of the strings passed to the :meth:`update` method so far. + This is a string of :attr:`digest_size` bytes which may contain non-ASCII + characters, including null bytes. + + +.. method:: hash.hexdigest() + + Like :meth:`digest` except the digest is returned as a string of double length, + containing only hexadecimal digits. This may be used to exchange the value + safely in email or other non-binary environments. + + +.. method:: hash.copy() + + Return a copy ("clone") of the hash object. This can be used to efficiently + compute the digests of strings that share a common initial substring. + + +.. seealso:: + + Module :mod:`hmac` + A module to generate message authentication codes using hashes. + + Module :mod:`base64` + Another way to encode binary hashes for non-binary environments. + + http://csrc.nist.gov/publications/fips/fips180-2/fips180-2.pdf + The FIPS 180-2 publication on Secure Hash Algorithms. + + http://www.cryptography.com/cnews/hash.html + Hash Collision FAQ with information on which algorithms have known issues and + what that means regarding their use. + diff --git a/Doc/library/heapq.rst b/Doc/library/heapq.rst new file mode 100644 index 0000000..2d38c26 --- /dev/null +++ b/Doc/library/heapq.rst @@ -0,0 +1,224 @@ + +:mod:`heapq` --- Heap queue algorithm +===================================== + +.. module:: heapq + :synopsis: Heap queue algorithm (a.k.a. priority queue). +.. moduleauthor:: Kevin O'Connor +.. sectionauthor:: Guido van Rossum +.. sectionauthor:: François Pinard + + +.. % Theoretical explanation: + +.. versionadded:: 2.3 + +This module provides an implementation of the heap queue algorithm, also known +as the priority queue algorithm. + +Heaps are arrays for which ``heap[k] <= heap[2*k+1]`` and ``heap[k] <= +heap[2*k+2]`` for all *k*, counting elements from zero. For the sake of +comparison, non-existing elements are considered to be infinite. The +interesting property of a heap is that ``heap[0]`` is always its smallest +element. + +The API below differs from textbook heap algorithms in two aspects: (a) We use +zero-based indexing. This makes the relationship between the index for a node +and the indexes for its children slightly less obvious, but is more suitable +since Python uses zero-based indexing. (b) Our pop method returns the smallest +item, not the largest (called a "min heap" in textbooks; a "max heap" is more +common in texts because of its suitability for in-place sorting). + +These two make it possible to view the heap as a regular Python list without +surprises: ``heap[0]`` is the smallest item, and ``heap.sort()`` maintains the +heap invariant! + +To create a heap, use a list initialized to ``[]``, or you can transform a +populated list into a heap via function :func:`heapify`. + +The following functions are provided: + + +.. function:: heappush(heap, item) + + Push the value *item* onto the *heap*, maintaining the heap invariant. + + +.. function:: heappop(heap) + + Pop and return the smallest item from the *heap*, maintaining the heap + invariant. If the heap is empty, :exc:`IndexError` is raised. + + +.. function:: heapify(x) + + Transform list *x* into a heap, in-place, in linear time. + + +.. function:: heapreplace(heap, item) + + Pop and return the smallest item from the *heap*, and also push the new *item*. + The heap size doesn't change. If the heap is empty, :exc:`IndexError` is raised. + This is more efficient than :func:`heappop` followed by :func:`heappush`, and + can be more appropriate when using a fixed-size heap. Note that the value + returned may be larger than *item*! That constrains reasonable uses of this + routine unless written as part of a conditional replacement:: + + if item > heap[0]: + item = heapreplace(heap, item) + +Example of use:: + + >>> from heapq import heappush, heappop + >>> heap = [] + >>> data = [1, 3, 5, 7, 9, 2, 4, 6, 8, 0] + >>> for item in data: + ... heappush(heap, item) + ... + >>> ordered = [] + >>> while heap: + ... ordered.append(heappop(heap)) + ... + >>> print ordered + [0, 1, 2, 3, 4, 5, 6, 7, 8, 9] + >>> data.sort() + >>> print data == ordered + True + >>> + +The module also offers three general purpose functions based on heaps. + + +.. function:: merge(*iterables) + + Merge multiple sorted inputs into a single sorted output (for example, merge + timestamped entries from multiple log files). Returns an iterator over over the + sorted values. + + Similar to ``sorted(itertools.chain(*iterables))`` but returns an iterable, does + not pull the data into memory all at once, and assumes that each of the input + streams is already sorted (smallest to largest). + + .. versionadded:: 2.6 + + +.. function:: nlargest(n, iterable[, key]) + + Return a list with the *n* largest elements from the dataset defined by + *iterable*. *key*, if provided, specifies a function of one argument that is + used to extract a comparison key from each element in the iterable: + ``key=str.lower`` Equivalent to: ``sorted(iterable, key=key, + reverse=True)[:n]`` + + .. versionadded:: 2.4 + + .. versionchanged:: 2.5 + Added the optional *key* argument. + + +.. function:: nsmallest(n, iterable[, key]) + + Return a list with the *n* smallest elements from the dataset defined by + *iterable*. *key*, if provided, specifies a function of one argument that is + used to extract a comparison key from each element in the iterable: + ``key=str.lower`` Equivalent to: ``sorted(iterable, key=key)[:n]`` + + .. versionadded:: 2.4 + + .. versionchanged:: 2.5 + Added the optional *key* argument. + +The latter two functions perform best for smaller values of *n*. For larger +values, it is more efficient to use the :func:`sorted` function. Also, when +``n==1``, it is more efficient to use the builtin :func:`min` and :func:`max` +functions. + + +Theory +------ + +(This explanation is due to François Pinard. The Python code for this module +was contributed by Kevin O'Connor.) + +Heaps are arrays for which ``a[k] <= a[2*k+1]`` and ``a[k] <= a[2*k+2]`` for all +*k*, counting elements from 0. For the sake of comparison, non-existing +elements are considered to be infinite. The interesting property of a heap is +that ``a[0]`` is always its smallest element. + +The strange invariant above is meant to be an efficient memory representation +for a tournament. The numbers below are *k*, not ``a[k]``:: + + 0 + + 1 2 + + 3 4 5 6 + + 7 8 9 10 11 12 13 14 + + 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 + +In the tree above, each cell *k* is topping ``2*k+1`` and ``2*k+2``. In an usual +binary tournament we see in sports, each cell is the winner over the two cells +it tops, and we can trace the winner down the tree to see all opponents s/he +had. However, in many computer applications of such tournaments, we do not need +to trace the history of a winner. To be more memory efficient, when a winner is +promoted, we try to replace it by something else at a lower level, and the rule +becomes that a cell and the two cells it tops contain three different items, but +the top cell "wins" over the two topped cells. + +If this heap invariant is protected at all time, index 0 is clearly the overall +winner. The simplest algorithmic way to remove it and find the "next" winner is +to move some loser (let's say cell 30 in the diagram above) into the 0 position, +and then percolate this new 0 down the tree, exchanging values, until the +invariant is re-established. This is clearly logarithmic on the total number of +items in the tree. By iterating over all items, you get an O(n log n) sort. + +A nice feature of this sort is that you can efficiently insert new items while +the sort is going on, provided that the inserted items are not "better" than the +last 0'th element you extracted. This is especially useful in simulation +contexts, where the tree holds all incoming events, and the "win" condition +means the smallest scheduled time. When an event schedule other events for +execution, they are scheduled into the future, so they can easily go into the +heap. So, a heap is a good structure for implementing schedulers (this is what +I used for my MIDI sequencer :-). + +Various structures for implementing schedulers have been extensively studied, +and heaps are good for this, as they are reasonably speedy, the speed is almost +constant, and the worst case is not much different than the average case. +However, there are other representations which are more efficient overall, yet +the worst cases might be terrible. + +Heaps are also very useful in big disk sorts. You most probably all know that a +big sort implies producing "runs" (which are pre-sorted sequences, which size is +usually related to the amount of CPU memory), followed by a merging passes for +these runs, which merging is often very cleverly organised [#]_. It is very +important that the initial sort produces the longest runs possible. Tournaments +are a good way to that. If, using all the memory available to hold a +tournament, you replace and percolate items that happen to fit the current run, +you'll produce runs which are twice the size of the memory for random input, and +much better for input fuzzily ordered. + +Moreover, if you output the 0'th item on disk and get an input which may not fit +in the current tournament (because the value "wins" over the last output value), +it cannot fit in the heap, so the size of the heap decreases. The freed memory +could be cleverly reused immediately for progressively building a second heap, +which grows at exactly the same rate the first heap is melting. When the first +heap completely vanishes, you switch heaps and start a new run. Clever and +quite effective! + +In a word, heaps are useful memory structures to know. I use them in a few +applications, and I think it is good to keep a 'heap' module around. :-) + +.. rubric:: Footnotes + +.. [#] The disk balancing algorithms which are current, nowadays, are more annoying + than clever, and this is a consequence of the seeking capabilities of the disks. + On devices which cannot seek, like big tape drives, the story was quite + different, and one had to be very clever to ensure (far in advance) that each + tape movement will be the most effective possible (that is, will best + participate at "progressing" the merge). Some tapes were even able to read + backwards, and this was also used to avoid the rewinding time. Believe me, real + good tape sorts were quite spectacular to watch! From all times, sorting has + always been a Great Art! :-) + diff --git a/Doc/library/hmac.rst b/Doc/library/hmac.rst new file mode 100644 index 0000000..10d41f7 --- /dev/null +++ b/Doc/library/hmac.rst @@ -0,0 +1,61 @@ + +:mod:`hmac` --- Keyed-Hashing for Message Authentication +======================================================== + +.. module:: hmac + :synopsis: Keyed-Hashing for Message Authentication (HMAC) implementation for Python. +.. moduleauthor:: Gerhard Häring +.. sectionauthor:: Gerhard Häring + + +.. versionadded:: 2.2 + +This module implements the HMAC algorithm as described by :rfc:`2104`. + + +.. function:: new(key[, msg[, digestmod]]) + + Return a new hmac object. If *msg* is present, the method call ``update(msg)`` + is made. *digestmod* is the digest constructor or module for the HMAC object to + use. It defaults to the :func:`hashlib.md5` constructor. + + .. note:: + + The md5 hash has known weaknesses but remains the default for backwards + compatibility. Choose a better one for your application. + +An HMAC object has the following methods: + + +.. method:: hmac.update(msg) + + Update the hmac object with the string *msg*. Repeated calls are equivalent to + a single call with the concatenation of all the arguments: ``m.update(a); + m.update(b)`` is equivalent to ``m.update(a + b)``. + + +.. method:: hmac.digest() + + Return the digest of the strings passed to the :meth:`update` method so far. + This string will be the same length as the *digest_size* of the digest given to + the constructor. It may contain non-ASCII characters, including NUL bytes. + + +.. method:: hmac.hexdigest() + + Like :meth:`digest` except the digest is returned as a string twice the length + containing only hexadecimal digits. This may be used to exchange the value + safely in email or other non-binary environments. + + +.. method:: hmac.copy() + + Return a copy ("clone") of the hmac object. This can be used to efficiently + compute the digests of strings that share a common initial substring. + + +.. seealso:: + + Module :mod:`hashlib` + The python module providing secure hash functions. + diff --git a/Doc/library/hotshot.rst b/Doc/library/hotshot.rst new file mode 100644 index 0000000..f6b5b13 --- /dev/null +++ b/Doc/library/hotshot.rst @@ -0,0 +1,152 @@ + +:mod:`hotshot` --- High performance logging profiler +==================================================== + +.. module:: hotshot + :synopsis: High performance logging profiler, mostly written in C. +.. moduleauthor:: Fred L. Drake, Jr. +.. sectionauthor:: Anthony Baxter + + +.. versionadded:: 2.2 + +This module provides a nicer interface to the :mod:`_hotshot` C module. Hotshot +is a replacement for the existing :mod:`profile` module. As it's written mostly +in C, it should result in a much smaller performance impact than the existing +:mod:`profile` module. + +.. note:: + + The :mod:`hotshot` module focuses on minimizing the overhead while profiling, at + the expense of long data post-processing times. For common usages it is + recommended to use :mod:`cProfile` instead. :mod:`hotshot` is not maintained and + might be removed from the standard library in the future. + +.. versionchanged:: 2.5 + the results should be more meaningful than in the past: the timing core + contained a critical bug. + +.. warning:: + + The :mod:`hotshot` profiler does not yet work well with threads. It is useful to + use an unthreaded script to run the profiler over the code you're interested in + measuring if at all possible. + + +.. class:: Profile(logfile[, lineevents[, linetimings]]) + + The profiler object. The argument *logfile* is the name of a log file to use for + logged profile data. The argument *lineevents* specifies whether to generate + events for every source line, or just on function call/return. It defaults to + ``0`` (only log function call/return). The argument *linetimings* specifies + whether to record timing information. It defaults to ``1`` (store timing + information). + + +.. _hotshot-objects: + +Profile Objects +--------------- + +Profile objects have the following methods: + + +.. method:: Profile.addinfo(key, value) + + Add an arbitrary labelled value to the profile output. + + +.. method:: Profile.close() + + Close the logfile and terminate the profiler. + + +.. method:: Profile.fileno() + + Return the file descriptor of the profiler's log file. + + +.. method:: Profile.run(cmd) + + Profile an :func:`exec`\ -compatible string in the script environment. The + globals from the :mod:`__main__` module are used as both the globals and locals + for the script. + + +.. method:: Profile.runcall(func, *args, **keywords) + + Profile a single call of a callable. Additional positional and keyword arguments + may be passed along; the result of the call is returned, and exceptions are + allowed to propagate cleanly, while ensuring that profiling is disabled on the + way out. + + +.. method:: Profile.runctx(cmd, globals, locals) + + Profile an :func:`exec`\ -compatible string in a specific environment. The + string is compiled before profiling begins. + + +.. method:: Profile.start() + + Start the profiler. + + +.. method:: Profile.stop() + + Stop the profiler. + + +Using hotshot data +------------------ + +.. module:: hotshot.stats + :synopsis: Statistical analysis for Hotshot + + +.. versionadded:: 2.2 + +This module loads hotshot profiling data into the standard :mod:`pstats` Stats +objects. + + +.. function:: load(filename) + + Load hotshot data from *filename*. Returns an instance of the + :class:`pstats.Stats` class. + + +.. seealso:: + + Module :mod:`profile` + The :mod:`profile` module's :class:`Stats` class + + +.. _hotshot-example: + +Example Usage +------------- + +Note that this example runs the python "benchmark" pystones. It can take some +time to run, and will produce large output files. :: + + >>> import hotshot, hotshot.stats, test.pystone + >>> prof = hotshot.Profile("stones.prof") + >>> benchtime, stones = prof.runcall(test.pystone.pystones) + >>> prof.close() + >>> stats = hotshot.stats.load("stones.prof") + >>> stats.strip_dirs() + >>> stats.sort_stats('time', 'calls') + >>> stats.print_stats(20) + 850004 function calls in 10.090 CPU seconds + + Ordered by: internal time, call count + + ncalls tottime percall cumtime percall filename:lineno(function) + 1 3.295 3.295 10.090 10.090 pystone.py:79(Proc0) + 150000 1.315 0.000 1.315 0.000 pystone.py:203(Proc7) + 50000 1.313 0.000 1.463 0.000 pystone.py:229(Func2) + . + . + . + diff --git a/Doc/library/htmllib.rst b/Doc/library/htmllib.rst new file mode 100644 index 0000000..96a7d08 --- /dev/null +++ b/Doc/library/htmllib.rst @@ -0,0 +1,186 @@ + +:mod:`htmllib` --- A parser for HTML documents +============================================== + +.. module:: htmllib + :synopsis: A parser for HTML documents. + + +.. index:: + single: HTML + single: hypertext + +.. index:: + module: sgmllib + module: formatter + single: SGMLParser (in module sgmllib) + +This module defines a class which can serve as a base for parsing text files +formatted in the HyperText Mark-up Language (HTML). The class is not directly +concerned with I/O --- it must be provided with input in string form via a +method, and makes calls to methods of a "formatter" object in order to produce +output. The :class:`HTMLParser` class is designed to be used as a base class +for other classes in order to add functionality, and allows most of its methods +to be extended or overridden. In turn, this class is derived from and extends +the :class:`SGMLParser` class defined in module :mod:`sgmllib`. The +:class:`HTMLParser` implementation supports the HTML 2.0 language as described +in :rfc:`1866`. Two implementations of formatter objects are provided in the +:mod:`formatter` module; refer to the documentation for that module for +information on the formatter interface. + +The following is a summary of the interface defined by +:class:`sgmllib.SGMLParser`: + +* The interface to feed data to an instance is through the :meth:`feed` method, + which takes a string argument. This can be called with as little or as much + text at a time as desired; ``p.feed(a); p.feed(b)`` has the same effect as + ``p.feed(a+b)``. When the data contains complete HTML markup constructs, these + are processed immediately; incomplete constructs are saved in a buffer. To + force processing of all unprocessed data, call the :meth:`close` method. + + For example, to parse the entire contents of a file, use:: + + parser.feed(open('myfile.html').read()) + parser.close() + +* The interface to define semantics for HTML tags is very simple: derive a class + and define methods called :meth:`start_tag`, :meth:`end_tag`, or :meth:`do_tag`. + The parser will call these at appropriate moments: :meth:`start_tag` or + :meth:`do_tag` is called when an opening tag of the form ```` is + encountered; :meth:`end_tag` is called when a closing tag of the form ```` + is encountered. If an opening tag requires a corresponding closing tag, like + ``

    `` ... ``

    ``, the class should define the :meth:`start_tag` method; if + a tag requires no closing tag, like ``

    ``, the class should define the + :meth:`do_tag` method. + +The module defines a parser class and an exception: + + +.. class:: HTMLParser(formatter) + + This is the basic HTML parser class. It supports all entity names required by + the XHTML 1.0 Recommendation (http://www.w3.org/TR/xhtml1). It also defines + handlers for all HTML 2.0 and many HTML 3.0 and 3.2 elements. + + +.. exception:: HTMLParseError + + Exception raised by the :class:`HTMLParser` class when it encounters an error + while parsing. + + .. versionadded:: 2.4 + + +.. seealso:: + + Module :mod:`formatter` + Interface definition for transforming an abstract flow of formatting events into + specific output events on writer objects. + + Module :mod:`HTMLParser` + Alternate HTML parser that offers a slightly lower-level view of the input, but + is designed to work with XHTML, and does not implement some of the SGML syntax + not used in "HTML as deployed" and which isn't legal for XHTML. + + Module :mod:`htmlentitydefs` + Definition of replacement text for XHTML 1.0 entities. + + Module :mod:`sgmllib` + Base class for :class:`HTMLParser`. + + +.. _html-parser-objects: + +HTMLParser Objects +------------------ + +In addition to tag methods, the :class:`HTMLParser` class provides some +additional methods and instance variables for use within tag methods. + + +.. attribute:: HTMLParser.formatter + + This is the formatter instance associated with the parser. + + +.. attribute:: HTMLParser.nofill + + Boolean flag which should be true when whitespace should not be collapsed, or + false when it should be. In general, this should only be true when character + data is to be treated as "preformatted" text, as within a ``

    `` element.
+   The default value is false.  This affects the operation of :meth:`handle_data`
+   and :meth:`save_end`.
+
+
+.. method:: HTMLParser.anchor_bgn(href, name, type)
+
+   This method is called at the start of an anchor region.  The arguments
+   correspond to the attributes of the ```` tag with the same names.  The
+   default implementation maintains a list of hyperlinks (defined by the ``HREF``
+   attribute for ```` tags) within the document.  The list of hyperlinks is
+   available as the data attribute :attr:`anchorlist`.
+
+
+.. method:: HTMLParser.anchor_end()
+
+   This method is called at the end of an anchor region.  The default
+   implementation adds a textual footnote marker using an index into the list of
+   hyperlinks created by :meth:`anchor_bgn`.
+
+
+.. method:: HTMLParser.handle_image(source, alt[, ismap[, align[, width[, height]]]])
+
+   This method is called to handle images.  The default implementation simply
+   passes the *alt* value to the :meth:`handle_data` method.
+
+
+.. method:: HTMLParser.save_bgn()
+
+   Begins saving character data in a buffer instead of sending it to the formatter
+   object.  Retrieve the stored data via :meth:`save_end`. Use of the
+   :meth:`save_bgn` / :meth:`save_end` pair may not be nested.
+
+
+.. method:: HTMLParser.save_end()
+
+   Ends buffering character data and returns all data saved since the preceding
+   call to :meth:`save_bgn`.  If the :attr:`nofill` flag is false, whitespace is
+   collapsed to single spaces.  A call to this method without a preceding call to
+   :meth:`save_bgn` will raise a :exc:`TypeError` exception.
+
+
+:mod:`htmlentitydefs` --- Definitions of HTML general entities
+==============================================================
+
+.. module:: htmlentitydefs
+   :synopsis: Definitions of HTML general entities.
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+This module defines three dictionaries, ``name2codepoint``, ``codepoint2name``,
+and ``entitydefs``. ``entitydefs`` is used by the :mod:`htmllib` module to
+provide the :attr:`entitydefs` member of the :class:`HTMLParser` class.  The
+definition provided here contains all the entities defined by XHTML 1.0  that
+can be handled using simple textual substitution in the Latin-1 character set
+(ISO-8859-1).
+
+
+.. data:: entitydefs
+
+   A dictionary mapping XHTML 1.0 entity definitions to their replacement text in
+   ISO Latin-1.
+
+
+.. data:: name2codepoint
+
+   A dictionary that maps HTML entity names to the Unicode codepoints.
+
+   .. versionadded:: 2.3
+
+
+.. data:: codepoint2name
+
+   A dictionary that maps Unicode codepoints to HTML entity names.
+
+   .. versionadded:: 2.3
+
diff --git a/Doc/library/htmlparser.rst b/Doc/library/htmlparser.rst
new file mode 100644
index 0000000..85a38fb
--- /dev/null
+++ b/Doc/library/htmlparser.rst
@@ -0,0 +1,183 @@
+
+:mod:`HTMLParser` --- Simple HTML and XHTML parser
+==================================================
+
+.. module:: HTMLParser
+   :synopsis: A simple parser that can handle HTML and XHTML.
+
+
+.. versionadded:: 2.2
+
+.. index::
+   single: HTML
+   single: XHTML
+
+This module defines a class :class:`HTMLParser` which serves as the basis for
+parsing text files formatted in HTML (HyperText Mark-up Language) and XHTML.
+Unlike the parser in :mod:`htmllib`, this parser is not based on the SGML parser
+in :mod:`sgmllib`.
+
+
+.. class:: HTMLParser()
+
+   The :class:`HTMLParser` class is instantiated without arguments.
+
+   An HTMLParser instance is fed HTML data and calls handler functions when tags
+   begin and end.  The :class:`HTMLParser` class is meant to be overridden by the
+   user to provide a desired behavior.
+
+   Unlike the parser in :mod:`htmllib`, this parser does not check that end tags
+   match start tags or call the end-tag handler for elements which are closed
+   implicitly by closing an outer element.
+
+An exception is defined as well:
+
+
+.. exception:: HTMLParseError
+
+   Exception raised by the :class:`HTMLParser` class when it encounters an error
+   while parsing.  This exception provides three attributes: :attr:`msg` is a brief
+   message explaining the error, :attr:`lineno` is the number of the line on which
+   the broken construct was detected, and :attr:`offset` is the number of
+   characters into the line at which the construct starts.
+
+:class:`HTMLParser` instances have the following methods:
+
+
+.. method:: HTMLParser.reset()
+
+   Reset the instance.  Loses all unprocessed data.  This is called implicitly at
+   instantiation time.
+
+
+.. method:: HTMLParser.feed(data)
+
+   Feed some text to the parser.  It is processed insofar as it consists of
+   complete elements; incomplete data is buffered until more data is fed or
+   :meth:`close` is called.
+
+
+.. method:: HTMLParser.close()
+
+   Force processing of all buffered data as if it were followed by an end-of-file
+   mark.  This method may be redefined by a derived class to define additional
+   processing at the end of the input, but the redefined version should always call
+   the :class:`HTMLParser` base class method :meth:`close`.
+
+
+.. method:: HTMLParser.getpos()
+
+   Return current line number and offset.
+
+
+.. method:: HTMLParser.get_starttag_text()
+
+   Return the text of the most recently opened start tag.  This should not normally
+   be needed for structured processing, but may be useful in dealing with HTML "as
+   deployed" or for re-generating input with minimal changes (whitespace between
+   attributes can be preserved, etc.).
+
+
+.. method:: HTMLParser.handle_starttag(tag, attrs)
+
+   This method is called to handle the start of a tag.  It is intended to be
+   overridden by a derived class; the base class implementation does nothing.
+
+   The *tag* argument is the name of the tag converted to lower case. The *attrs*
+   argument is a list of ``(name, value)`` pairs containing the attributes found
+   inside the tag's ``<>`` brackets.  The *name* will be translated to lower case,
+   and quotes in the *value* have been removed, and character and entity references
+   have been replaced.  For instance, for the tag ````, this method would be called as
+   ``handle_starttag('a', [('href', 'http://www.cwi.nl/')])``.
+
+   .. versionchanged:: 2.6
+      All entity references from htmlentitydefs are now replaced in the attribute
+      values.
+
+
+.. method:: HTMLParser.handle_startendtag(tag, attrs)
+
+   Similar to :meth:`handle_starttag`, but called when the parser encounters an
+   XHTML-style empty tag (````).  This method may be overridden by
+   subclasses which require this particular lexical information; the default
+   implementation simple calls :meth:`handle_starttag` and :meth:`handle_endtag`.
+
+
+.. method:: HTMLParser.handle_endtag(tag)
+
+   This method is called to handle the end tag of an element.  It is intended to be
+   overridden by a derived class; the base class implementation does nothing.  The
+   *tag* argument is the name of the tag converted to lower case.
+
+
+.. method:: HTMLParser.handle_data(data)
+
+   This method is called to process arbitrary data.  It is intended to be
+   overridden by a derived class; the base class implementation does nothing.
+
+
+.. method:: HTMLParser.handle_charref(name)
+
+   This method is called to process a character reference of the form ``&#ref;``.
+   It is intended to be overridden by a derived class; the base class
+   implementation does nothing.
+
+
+.. method:: HTMLParser.handle_entityref(name)
+
+   This method is called to process a general entity reference of the form
+   ``&name;`` where *name* is an general entity reference.  It is intended to be
+   overridden by a derived class; the base class implementation does nothing.
+
+
+.. method:: HTMLParser.handle_comment(data)
+
+   This method is called when a comment is encountered.  The *comment* argument is
+   a string containing the text between the ``--`` and ``--`` delimiters, but not
+   the delimiters themselves.  For example, the comment ```` will cause
+   this method to be called with the argument ``'text'``.  It is intended to be
+   overridden by a derived class; the base class implementation does nothing.
+
+
+.. method:: HTMLParser.handle_decl(decl)
+
+   Method called when an SGML declaration is read by the parser.  The *decl*
+   parameter will be the entire contents of the declaration inside the ```` markup.  It is intended to be overridden by a derived class; the base
+   class implementation does nothing.
+
+
+.. method:: HTMLParser.handle_pi(data)
+
+   Method called when a processing instruction is encountered.  The *data*
+   parameter will contain the entire processing instruction. For example, for the
+   processing instruction ````, this method would be called as
+   ``handle_pi("proc color='red'")``.  It is intended to be overridden by a derived
+   class; the base class implementation does nothing.
+
+   .. note::
+
+      The :class:`HTMLParser` class uses the SGML syntactic rules for processing
+      instructions.  An XHTML processing instruction using the trailing ``'?'`` will
+      cause the ``'?'`` to be included in *data*.
+
+
+.. _htmlparser-example:
+
+Example HTML Parser Application
+-------------------------------
+
+As a basic example, below is a very basic HTML parser that uses the
+:class:`HTMLParser` class to print out tags as they are encountered::
+
+   from HTMLParser import HTMLParser
+
+   class MyHTMLParser(HTMLParser):
+
+       def handle_starttag(self, tag, attrs):
+           print "Encountered the beginning of a %s tag" % tag
+
+       def handle_endtag(self, tag):
+           print "Encountered the end of a %s tag" % tag
+
diff --git a/Doc/library/httplib.rst b/Doc/library/httplib.rst
new file mode 100644
index 0000000..aae2219
--- /dev/null
+++ b/Doc/library/httplib.rst
@@ -0,0 +1,552 @@
+
+:mod:`httplib` --- HTTP protocol client
+=======================================
+
+.. module:: httplib
+   :synopsis: HTTP and HTTPS protocol client (requires sockets).
+
+
+.. index::
+   pair: HTTP; protocol
+   single: HTTP; httplib (standard module)
+
+.. index:: module: urllib
+
+This module defines classes which implement the client side of the HTTP and
+HTTPS protocols.  It is normally not used directly --- the module :mod:`urllib`
+uses it to handle URLs that use HTTP and HTTPS.
+
+.. note::
+
+   HTTPS support is only available if the :mod:`socket` module was compiled with
+   SSL support.
+
+.. note::
+
+   The public interface for this module changed substantially in Python 2.0.  The
+   :class:`HTTP` class is retained only for backward compatibility with 1.5.2.  It
+   should not be used in new code.  Refer to the online docstrings for usage.
+
+The module provides the following classes:
+
+
+.. class:: HTTPConnection(host[, port[, strict[, timeout]]])
+
+   An :class:`HTTPConnection` instance represents one transaction with an HTTP
+   server.  It should be instantiated passing it a host and optional port number.
+   If no port number is passed, the port is extracted from the host string if it
+   has the form ``host:port``, else the default HTTP port (80) is used.  When True,
+   the optional parameter *strict* causes ``BadStatusLine`` to be raised if the
+   status line can't be parsed as a valid HTTP/1.0 or 1.1 status line.  If the
+   optional *timeout* parameter is given, connection attempts will timeout after
+   that many seconds (if it is not given or ``None``, the global default  timeout
+   setting is used).
+
+   For example, the following calls all create instances that connect to the server
+   at the same host and port::
+
+      >>> h1 = httplib.HTTPConnection('www.cwi.nl')
+      >>> h2 = httplib.HTTPConnection('www.cwi.nl:80')
+      >>> h3 = httplib.HTTPConnection('www.cwi.nl', 80)
+      >>> h3 = httplib.HTTPConnection('www.cwi.nl', 80, timeout=10)
+
+   .. versionadded:: 2.0
+
+   .. versionchanged:: 2.6
+      *timeout* was added.
+
+
+.. class:: HTTPSConnection(host[, port[, key_file[, cert_file[, strict[, timeout]]]]])
+
+   A subclass of :class:`HTTPConnection` that uses SSL for communication with
+   secure servers.  Default port is ``443``. *key_file* is the name of a PEM
+   formatted file that contains your private key. *cert_file* is a PEM formatted
+   certificate chain file.
+
+   .. warning::
+
+      This does not do any certificate verification!
+
+   .. versionadded:: 2.0
+
+   .. versionchanged:: 2.6
+      *timeout* was added.
+
+
+.. class:: HTTPResponse(sock[, debuglevel=0][, strict=0])
+
+   Class whose instances are returned upon successful connection.  Not instantiated
+   directly by user.
+
+   .. versionadded:: 2.0
+
+The following exceptions are raised as appropriate:
+
+
+.. exception:: HTTPException
+
+   The base class of the other exceptions in this module.  It is a subclass of
+   :exc:`Exception`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: NotConnected
+
+   A subclass of :exc:`HTTPException`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: InvalidURL
+
+   A subclass of :exc:`HTTPException`, raised if a port is given and is either
+   non-numeric or empty.
+
+   .. versionadded:: 2.3
+
+
+.. exception:: UnknownProtocol
+
+   A subclass of :exc:`HTTPException`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: UnknownTransferEncoding
+
+   A subclass of :exc:`HTTPException`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: UnimplementedFileMode
+
+   A subclass of :exc:`HTTPException`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: IncompleteRead
+
+   A subclass of :exc:`HTTPException`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: ImproperConnectionState
+
+   A subclass of :exc:`HTTPException`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: CannotSendRequest
+
+   A subclass of :exc:`ImproperConnectionState`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: CannotSendHeader
+
+   A subclass of :exc:`ImproperConnectionState`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: ResponseNotReady
+
+   A subclass of :exc:`ImproperConnectionState`.
+
+   .. versionadded:: 2.0
+
+
+.. exception:: BadStatusLine
+
+   A subclass of :exc:`HTTPException`.  Raised if a server responds with a HTTP
+   status code that we don't understand.
+
+   .. versionadded:: 2.0
+
+The constants defined in this module are:
+
+
+.. data:: HTTP_PORT
+
+   The default port for the HTTP protocol (always ``80``).
+
+
+.. data:: HTTPS_PORT
+
+   The default port for the HTTPS protocol (always ``443``).
+
+and also the following constants for integer status codes:
+
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| Constant                                 | Value   | Definition                                                            |
++==========================================+=========+=======================================================================+
+| :const:`CONTINUE`                        | ``100`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.1.1                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`SWITCHING_PROTOCOLS`             | ``101`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.1.2                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`PROCESSING`                      | ``102`` | WEBDAV, `RFC 2518, Section 10.1                                       |
+|                                          |         | `_               |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`OK`                              | ``200`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.2.1                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`CREATED`                         | ``201`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.2.2                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`ACCEPTED`                        | ``202`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.2.3                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`NON_AUTHORITATIVE_INFORMATION`   | ``203`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.2.4                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`NO_CONTENT`                      | ``204`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.2.5                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`RESET_CONTENT`                   | ``205`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.2.6                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`PARTIAL_CONTENT`                 | ``206`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.2.7                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`MULTI_STATUS`                    | ``207`` | WEBDAV `RFC 2518, Section 10.2                                        |
+|                                          |         | `_               |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`IM_USED`                         | ``226`` | Delta encoding in HTTP,                                               |
+|                                          |         | :rfc:`3229`, Section 10.4.1                                           |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`MULTIPLE_CHOICES`                | ``300`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.3.1                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`MOVED_PERMANENTLY`               | ``301`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.3.2                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`FOUND`                           | ``302`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.3.3                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`SEE_OTHER`                       | ``303`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.3.4                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`NOT_MODIFIED`                    | ``304`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.3.5                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`USE_PROXY`                       | ``305`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.3.6                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`TEMPORARY_REDIRECT`              | ``307`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.3.8                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`BAD_REQUEST`                     | ``400`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.1                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`UNAUTHORIZED`                    | ``401`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.2                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`PAYMENT_REQUIRED`                | ``402`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.3                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`FORBIDDEN`                       | ``403`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.4                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`NOT_FOUND`                       | ``404`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.5                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`METHOD_NOT_ALLOWED`              | ``405`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.6                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`NOT_ACCEPTABLE`                  | ``406`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.7                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`PROXY_AUTHENTICATION_REQUIRED`   | ``407`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.8                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`REQUEST_TIMEOUT`                 | ``408`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.9                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`CONFLICT`                        | ``409`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.10                                                               |
+|                                          |         | `_ |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`GONE`                            | ``410`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.11                                                               |
+|                                          |         | `_ |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`LENGTH_REQUIRED`                 | ``411`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.12                                                               |
+|                                          |         | `_ |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`PRECONDITION_FAILED`             | ``412`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.13                                                               |
+|                                          |         | `_ |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`REQUEST_ENTITY_TOO_LARGE`        | ``413`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.14                                                               |
+|                                          |         | `_ |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`REQUEST_URI_TOO_LONG`            | ``414`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.15                                                               |
+|                                          |         | `_ |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`UNSUPPORTED_MEDIA_TYPE`          | ``415`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.16                                                               |
+|                                          |         | `_ |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`REQUESTED_RANGE_NOT_SATISFIABLE` | ``416`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.17                                                               |
+|                                          |         | `_ |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`EXPECTATION_FAILED`              | ``417`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.4.18                                                               |
+|                                          |         | `_ |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`UNPROCESSABLE_ENTITY`            | ``422`` | WEBDAV, `RFC 2518, Section 10.3                                       |
+|                                          |         | `_               |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`LOCKED`                          | ``423`` | WEBDAV `RFC 2518, Section 10.4                                        |
+|                                          |         | `_               |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`FAILED_DEPENDENCY`               | ``424`` | WEBDAV, `RFC 2518, Section 10.5                                       |
+|                                          |         | `_               |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`UPGRADE_REQUIRED`                | ``426`` | HTTP Upgrade to TLS,                                                  |
+|                                          |         | :rfc:`2817`, Section 6                                                |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`INTERNAL_SERVER_ERROR`           | ``500`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.5.1                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`NOT_IMPLEMENTED`                 | ``501`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.5.2                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`BAD_GATEWAY`                     | ``502`` | HTTP/1.1 `RFC 2616, Section                                           |
+|                                          |         | 10.5.3                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`SERVICE_UNAVAILABLE`             | ``503`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.5.4                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`GATEWAY_TIMEOUT`                 | ``504`` | HTTP/1.1 `RFC 2616, Section                                           |
+|                                          |         | 10.5.5                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`HTTP_VERSION_NOT_SUPPORTED`      | ``505`` | HTTP/1.1, `RFC 2616, Section                                          |
+|                                          |         | 10.5.6                                                                |
+|                                          |         | `_  |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`INSUFFICIENT_STORAGE`            | ``507`` | WEBDAV, `RFC 2518, Section 10.6                                       |
+|                                          |         | `_               |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+| :const:`NOT_EXTENDED`                    | ``510`` | An HTTP Extension Framework,                                          |
+|                                          |         | :rfc:`2774`, Section 7                                                |
++------------------------------------------+---------+-----------------------------------------------------------------------+
+
+
+.. data:: responses
+
+   This dictionary maps the HTTP 1.1 status codes to the W3C names.
+
+   Example: ``httplib.responses[httplib.NOT_FOUND]`` is ``'Not Found'``.
+
+   .. versionadded:: 2.5
+
+
+.. _httpconnection-objects:
+
+HTTPConnection Objects
+----------------------
+
+:class:`HTTPConnection` instances have the following methods:
+
+
+.. method:: HTTPConnection.request(method, url[, body[, headers]])
+
+   This will send a request to the server using the HTTP request method *method*
+   and the selector *url*.  If the *body* argument is present, it should be a
+   string of data to send after the headers are finished. Alternatively, it may
+   be an open file object, in which case the contents of the file is sent; this
+   file object should support ``fileno()`` and ``read()`` methods. The header
+   Content-Length is automatically set to the correct value. The *headers*
+   argument should be a mapping of extra HTTP headers to send with the request.
+
+   .. versionchanged:: 2.6
+      *body* can be a file object.
+
+
+.. method:: HTTPConnection.getresponse()
+
+   Should be called after a request is sent to get the response from the server.
+   Returns an :class:`HTTPResponse` instance.
+
+   .. note::
+
+      Note that you must have read the whole response before you can send a new
+      request to the server.
+
+
+.. method:: HTTPConnection.set_debuglevel(level)
+
+   Set the debugging level (the amount of debugging output printed). The default
+   debug level is ``0``, meaning no debugging output is printed.
+
+
+.. method:: HTTPConnection.connect()
+
+   Connect to the server specified when the object was created.
+
+
+.. method:: HTTPConnection.close()
+
+   Close the connection to the server.
+
+As an alternative to using the :meth:`request` method described above, you can
+also send your request step by step, by using the four functions below.
+
+
+.. method:: HTTPConnection.putrequest(request, selector[, skip_host[, skip_accept_encoding]])
+
+   This should be the first call after the connection to the server has been made.
+   It sends a line to the server consisting of the *request* string, the *selector*
+   string, and the HTTP version (``HTTP/1.1``).  To disable automatic sending of
+   ``Host:`` or ``Accept-Encoding:`` headers (for example to accept additional
+   content encodings), specify *skip_host* or *skip_accept_encoding* with non-False
+   values.
+
+   .. versionchanged:: 2.4
+      *skip_accept_encoding* argument added.
+
+
+.. method:: HTTPConnection.putheader(header, argument[, ...])
+
+   Send an :rfc:`822`\ -style header to the server.  It sends a line to the server
+   consisting of the header, a colon and a space, and the first argument.  If more
+   arguments are given, continuation lines are sent, each consisting of a tab and
+   an argument.
+
+
+.. method:: HTTPConnection.endheaders()
+
+   Send a blank line to the server, signalling the end of the headers.
+
+
+.. method:: HTTPConnection.send(data)
+
+   Send data to the server.  This should be used directly only after the
+   :meth:`endheaders` method has been called and before :meth:`getresponse` is
+   called.
+
+
+.. _httpresponse-objects:
+
+HTTPResponse Objects
+--------------------
+
+:class:`HTTPResponse` instances have the following methods and attributes:
+
+
+.. method:: HTTPResponse.read([amt])
+
+   Reads and returns the response body, or up to the next *amt* bytes.
+
+
+.. method:: HTTPResponse.getheader(name[, default])
+
+   Get the contents of the header *name*, or *default* if there is no matching
+   header.
+
+
+.. method:: HTTPResponse.getheaders()
+
+   Return a list of (header, value) tuples.
+
+   .. versionadded:: 2.4
+
+
+.. attribute:: HTTPResponse.msg
+
+   A :class:`mimetools.Message` instance containing the response headers.
+
+
+.. attribute:: HTTPResponse.version
+
+   HTTP protocol version used by server.  10 for HTTP/1.0, 11 for HTTP/1.1.
+
+
+.. attribute:: HTTPResponse.status
+
+   Status code returned by server.
+
+
+.. attribute:: HTTPResponse.reason
+
+   Reason phrase returned by server.
+
+
+.. _httplib-examples:
+
+Examples
+--------
+
+Here is an example session that uses the ``GET`` method::
+
+   >>> import httplib
+   >>> conn = httplib.HTTPConnection("www.python.org")
+   >>> conn.request("GET", "/index.html")
+   >>> r1 = conn.getresponse()
+   >>> print r1.status, r1.reason
+   200 OK
+   >>> data1 = r1.read()
+   >>> conn.request("GET", "/parrot.spam")
+   >>> r2 = conn.getresponse()
+   >>> print r2.status, r2.reason
+   404 Not Found
+   >>> data2 = r2.read()
+   >>> conn.close()
+
+Here is an example session that shows how to ``POST`` requests::
+
+   >>> import httplib, urllib
+   >>> params = urllib.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
+   >>> headers = {"Content-type": "application/x-www-form-urlencoded",
+   ...            "Accept": "text/plain"}
+   >>> conn = httplib.HTTPConnection("musi-cal.mojam.com:80")
+   >>> conn.request("POST", "/cgi-bin/query", params, headers)
+   >>> response = conn.getresponse()
+   >>> print response.status, response.reason
+   200 OK
+   >>> data = response.read()
+   >>> conn.close()
+
diff --git a/Doc/library/i18n.rst b/Doc/library/i18n.rst
new file mode 100644
index 0000000..8e57102
--- /dev/null
+++ b/Doc/library/i18n.rst
@@ -0,0 +1,19 @@
+
+.. _i18n:
+
+********************
+Internationalization
+********************
+
+The modules described in this chapter help you write software that is
+independent of language and locale by providing mechanisms for selecting a
+language to be used in  program messages or by tailoring output to match local
+conventions.
+
+The list of modules described in this chapter is:
+
+
+.. toctree::
+
+   gettext.rst
+   locale.rst
diff --git a/Doc/library/ic.rst b/Doc/library/ic.rst
new file mode 100644
index 0000000..d5e03bd
--- /dev/null
+++ b/Doc/library/ic.rst
@@ -0,0 +1,119 @@
+
+:mod:`ic` --- Access to the Mac OS X Internet Config
+====================================================
+
+.. module:: ic
+   :platform: Mac
+   :synopsis: Access to the Mac OS X Internet Config.
+
+
+This module provides access to various internet-related preferences set through
+:program:`System Preferences` or the :program:`Finder`.
+
+.. index:: module: icglue
+
+There is a low-level companion module :mod:`icglue` which provides the basic
+Internet Config access functionality.  This low-level module is not documented,
+but the docstrings of the routines document the parameters and the routine names
+are the same as for the Pascal or C API to Internet Config, so the standard IC
+programmers' documentation can be used if this module is needed.
+
+The :mod:`ic` module defines the :exc:`error` exception and symbolic names for
+all error codes Internet Config can produce; see the source for details.
+
+
+.. exception:: error
+
+   Exception raised on errors in the :mod:`ic` module.
+
+The :mod:`ic` module defines the following class and function:
+
+
+.. class:: IC([signature[, ic]])
+
+   Create an Internet Config object. The signature is a 4-character creator code of
+   the current application (default ``'Pyth'``) which may influence some of ICs
+   settings. The optional *ic* argument is a low-level ``icglue.icinstance``
+   created beforehand, this may be useful if you want to get preferences from a
+   different config file, etc.
+
+
+.. function:: launchurl(url[, hint])
+              parseurl(data[, start[, end[, hint]]])
+              mapfile(file)
+              maptypecreator(type, creator[, filename])
+              settypecreator(file)
+
+   These functions are "shortcuts" to the methods of the same name, described
+   below.
+
+
+IC Objects
+----------
+
+:class:`IC` objects have a mapping interface, hence to obtain the mail address
+you simply get ``ic['MailAddress']``. Assignment also works, and changes the
+option in the configuration file.
+
+The module knows about various datatypes, and converts the internal IC
+representation to a "logical" Python data structure. Running the :mod:`ic`
+module standalone will run a test program that lists all keys and values in your
+IC database, this will have to serve as documentation.
+
+If the module does not know how to represent the data it returns an instance of
+the ``ICOpaqueData`` type, with the raw data in its :attr:`data` attribute.
+Objects of this type are also acceptable values for assignment.
+
+Besides the dictionary interface, :class:`IC` objects have the following
+methods:
+
+
+.. method:: IC.launchurl(url[, hint])
+
+   Parse the given URL, launch the correct application and pass it the URL. The
+   optional *hint* can be a scheme name such as ``'mailto:'``, in which case
+   incomplete URLs are completed with this scheme.  If *hint* is not provided,
+   incomplete URLs are invalid.
+
+
+.. method:: IC.parseurl(data[, start[, end[, hint]]])
+
+   Find an URL somewhere in *data* and return start position, end position and the
+   URL. The optional *start* and *end* can be used to limit the search, so for
+   instance if a user clicks in a long text field you can pass the whole text field
+   and the click-position in *start* and this routine will return the whole URL in
+   which the user clicked.  As above, *hint* is an optional scheme used to complete
+   incomplete URLs.
+
+
+.. method:: IC.mapfile(file)
+
+   Return the mapping entry for the given *file*, which can be passed as either a
+   filename or an :func:`FSSpec` result, and which need not exist.
+
+   The mapping entry is returned as a tuple ``(version, type, creator, postcreator,
+   flags, extension, appname, postappname, mimetype, entryname)``, where *version*
+   is the entry version number, *type* is the 4-character filetype, *creator* is
+   the 4-character creator type, *postcreator* is the 4-character creator code of
+   an optional application to post-process the file after downloading, *flags* are
+   various bits specifying whether to transfer in binary or ascii and such,
+   *extension* is the filename extension for this file type, *appname* is the
+   printable name of the application to which this file belongs, *postappname* is
+   the name of the postprocessing application, *mimetype* is the MIME type of this
+   file and *entryname* is the name of this entry.
+
+
+.. method:: IC.maptypecreator(type, creator[, filename])
+
+   Return the mapping entry for files with given 4-character *type* and *creator*
+   codes. The optional *filename* may be specified to further help finding the
+   correct entry (if the creator code is ``'????'``, for instance).
+
+   The mapping entry is returned in the same format as for *mapfile*.
+
+
+.. method:: IC.settypecreator(file)
+
+   Given an existing *file*, specified either as a filename or as an :func:`FSSpec`
+   result, set its creator and type correctly based on its extension.  The finder
+   is told about the change, so the finder icon will be updated quickly.
diff --git a/Doc/library/idle.rst b/Doc/library/idle.rst
new file mode 100644
index 0000000..44b59e9
--- /dev/null
+++ b/Doc/library/idle.rst
@@ -0,0 +1,288 @@
+.. _idle:
+
+Idle
+====
+
+.. moduleauthor:: Guido van Rossum 
+
+
+.. % \declaremodule{standard}{idle}
+.. % \modulesynopsis{A Python Integrated Development Environment}
+
+.. index::
+   single: Idle
+   single: Python Editor
+   single: Integrated Development Environment
+
+Idle is the Python IDE built with the :mod:`Tkinter` GUI toolkit.
+
+IDLE has the following features:
+
+* coded in 100% pure Python, using the :mod:`Tkinter` GUI toolkit
+
+* cross-platform: works on Windows and Unix (on Mac OS, there are currently
+  problems with Tcl/Tk)
+
+* multi-window text editor with multiple undo, Python colorizing and many other
+  features, e.g. smart indent and call tips
+
+* Python shell window (a.k.a. interactive interpreter)
+
+* debugger (not complete, but you can set breakpoints, view  and step)
+
+
+Menus
+-----
+
+
+File menu
+^^^^^^^^^
+
+New window
+   create a new editing window
+
+Open...
+   open an existing file
+
+Open module...
+   open an existing module (searches sys.path)
+
+Class browser
+   show classes and methods in current file
+
+Path browser
+   show sys.path directories, modules, classes and methods
+
+.. index::
+   single: Class browser
+   single: Path browser
+
+Save
+   save current window to the associated file (unsaved windows have a \* before and
+   after the window title)
+
+Save As...
+   save current window to new file, which becomes the associated file
+
+Save Copy As...
+   save current window to different file without changing the associated file
+
+Close
+   close current window (asks to save if unsaved)
+
+Exit
+   close all windows and quit IDLE (asks to save if unsaved)
+
+
+Edit menu
+^^^^^^^^^
+
+Undo
+   Undo last change to current window (max 1000 changes)
+
+Redo
+   Redo last undone change to current window
+
+Cut
+   Copy selection into system-wide clipboard; then delete selection
+
+Copy
+   Copy selection into system-wide clipboard
+
+Paste
+   Insert system-wide clipboard into window
+
+Select All
+   Select the entire contents of the edit buffer
+
+Find...
+   Open a search dialog box with many options
+
+Find again
+   Repeat last search
+
+Find selection
+   Search for the string in the selection
+
+Find in Files...
+   Open a search dialog box for searching files
+
+Replace...
+   Open a search-and-replace dialog box
+
+Go to line
+   Ask for a line number and show that line
+
+Indent region
+   Shift selected lines right 4 spaces
+
+Dedent region
+   Shift selected lines left 4 spaces
+
+Comment out region
+   Insert ## in front of selected lines
+
+Uncomment region
+   Remove leading # or ## from selected lines
+
+Tabify region
+   Turns *leading* stretches of spaces into tabs
+
+Untabify region
+   Turn *all* tabs into the right number of spaces
+
+Expand word
+   Expand the word you have typed to match another word in the same buffer; repeat
+   to get a different expansion
+
+Format Paragraph
+   Reformat the current blank-line-separated paragraph
+
+Import module
+   Import or reload the current module
+
+Run script
+   Execute the current file in the __main__ namespace
+
+.. index::
+   single: Import module
+   single: Run script
+
+
+Windows menu
+^^^^^^^^^^^^
+
+Zoom Height
+   toggles the window between normal size (24x80) and maximum height.
+
+The rest of this menu lists the names of all open windows; select one to bring
+it to the foreground (deiconifying it if necessary).
+
+
+Debug menu (in the Python Shell window only)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Go to file/line
+   look around the insert point for a filename and linenumber, open the file, and
+   show the line.
+
+Open stack viewer
+   show the stack traceback of the last exception
+
+Debugger toggle
+   Run commands in the shell under the debugger
+
+JIT Stack viewer toggle
+   Open stack viewer on traceback
+
+.. index::
+   single: stack viewer
+   single: debugger
+
+
+Basic editing and navigation
+----------------------------
+
+* :kbd:`Backspace` deletes to the left; :kbd:`Del` deletes to the right
+
+* Arrow keys and :kbd:`Page Up`/:kbd:`Page Down` to move around
+
+* :kbd:`Home`/:kbd:`End` go to begin/end of line
+
+* :kbd:`C-Home`/:kbd:`C-End` go to begin/end of file
+
+* Some :program:`Emacs` bindings may also work, including :kbd:`C-B`,
+  :kbd:`C-P`, :kbd:`C-A`, :kbd:`C-E`, :kbd:`C-D`, :kbd:`C-L`
+
+
+Automatic indentation
+^^^^^^^^^^^^^^^^^^^^^
+
+After a block-opening statement, the next line is indented by 4 spaces (in the
+Python Shell window by one tab).  After certain keywords (break, return etc.)
+the next line is dedented.  In leading indentation, :kbd:`Backspace` deletes up
+to 4 spaces if they are there. :kbd:`Tab` inserts 1-4 spaces (in the Python
+Shell window one tab). See also the indent/dedent region commands in the edit
+menu.
+
+
+Python Shell window
+^^^^^^^^^^^^^^^^^^^
+
+* :kbd:`C-C` interrupts executing command
+
+* :kbd:`C-D` sends end-of-file; closes window if typed at a ``>>>`` prompt
+
+* :kbd:`Alt-p` retrieves previous command matching what you have typed
+
+* :kbd:`Alt-n` retrieves next
+
+* :kbd:`Return` while on any previous command retrieves that command
+
+* :kbd:`Alt-/` (Expand word) is also useful here
+
+.. index:: single: indentation
+
+
+Syntax colors
+-------------
+
+The coloring is applied in a background "thread," so you may occasionally see
+uncolorized text.  To change the color scheme, edit the ``[Colors]`` section in
+:file:`config.txt`.
+
+Python syntax colors:
+   Keywords
+      orange
+
+   Strings 
+      green
+
+   Comments
+      red
+
+   Definitions
+      blue
+
+Shell colors:
+   Console output
+      brown
+
+   stdout
+      blue
+
+   stderr
+      dark green
+
+   stdin
+      black
+
+
+Command line usage
+^^^^^^^^^^^^^^^^^^
+
+::
+
+   idle.py [-c command] [-d] [-e] [-s] [-t title] [arg] ...
+
+   -c command  run this command
+   -d          enable debugger
+   -e          edit mode; arguments are files to be edited
+   -s          run $IDLESTARTUP or $PYTHONSTARTUP first
+   -t title    set title of shell window
+
+If there are arguments:
+
+#. If :option:`-e` is used, arguments are files opened for editing and
+   ``sys.argv`` reflects the arguments passed to IDLE itself.
+
+#. Otherwise, if :option:`-c` is used, all arguments are placed in
+   ``sys.argv[1:...]``, with ``sys.argv[0]`` set to ``'-c'``.
+
+#. Otherwise, if neither :option:`-e` nor :option:`-c` is used, the first
+   argument is a script which is executed with the remaining arguments in
+   ``sys.argv[1:...]``  and ``sys.argv[0]`` set to the script name.  If the script
+   name is '-', no script is executed but an interactive Python session is started;
+   the arguments are still available in ``sys.argv``.
+
+
diff --git a/Doc/library/imaplib.rst b/Doc/library/imaplib.rst
new file mode 100644
index 0000000..fc7c230
--- /dev/null
+++ b/Doc/library/imaplib.rst
@@ -0,0 +1,540 @@
+
+:mod:`imaplib` --- IMAP4 protocol client
+========================================
+
+.. module:: imaplib
+   :synopsis: IMAP4 protocol client (requires sockets).
+.. moduleauthor:: Piers Lauder 
+.. sectionauthor:: Piers Lauder 
+
+
+.. index::
+   pair: IMAP4; protocol
+   pair: IMAP4_SSL; protocol
+   pair: IMAP4_stream; protocol
+
+.. % Based on HTML documentation by Piers Lauder
+.. % ;
+.. % converted by Fred L. Drake, Jr. .
+.. % Revised by ESR, January 2000.
+.. % Changes for IMAP4_SSL by Tino Lange , March 2002
+.. % Changes for IMAP4_stream by Piers Lauder
+.. % , November 2002
+
+This module defines three classes, :class:`IMAP4`, :class:`IMAP4_SSL` and
+:class:`IMAP4_stream`, which encapsulate a connection to an IMAP4 server and
+implement a large subset of the IMAP4rev1 client protocol as defined in
+:rfc:`2060`. It is backward compatible with IMAP4 (:rfc:`1730`) servers, but
+note that the ``STATUS`` command is not supported in IMAP4.
+
+Three classes are provided by the :mod:`imaplib` module, :class:`IMAP4` is the
+base class:
+
+
+.. class:: IMAP4([host[, port]])
+
+   This class implements the actual IMAP4 protocol.  The connection is created and
+   protocol version (IMAP4 or IMAP4rev1) is determined when the instance is
+   initialized. If *host* is not specified, ``''`` (the local host) is used. If
+   *port* is omitted, the standard IMAP4 port (143) is used.
+
+Three exceptions are defined as attributes of the :class:`IMAP4` class:
+
+
+.. exception:: IMAP4.error
+
+   Exception raised on any errors.  The reason for the exception is passed to the
+   constructor as a string.
+
+
+.. exception:: IMAP4.abort
+
+   IMAP4 server errors cause this exception to be raised.  This is a sub-class of
+   :exc:`IMAP4.error`.  Note that closing the instance and instantiating a new one
+   will usually allow recovery from this exception.
+
+
+.. exception:: IMAP4.readonly
+
+   This exception is raised when a writable mailbox has its status changed by the
+   server.  This is a sub-class of :exc:`IMAP4.error`.  Some other client now has
+   write permission, and the mailbox will need to be re-opened to re-obtain write
+   permission.
+
+There's also a subclass for secure connections:
+
+
+.. class:: IMAP4_SSL([host[, port[, keyfile[, certfile]]]])
+
+   This is a subclass derived from :class:`IMAP4` that connects over an SSL
+   encrypted socket (to use this class you need a socket module that was compiled
+   with SSL support).  If *host* is not specified, ``''`` (the local host) is used.
+   If *port* is omitted, the standard IMAP4-over-SSL port (993) is used.  *keyfile*
+   and *certfile* are also optional - they can contain a PEM formatted private key
+   and certificate chain file for the SSL connection.
+
+The second subclass allows for connections created by a child process:
+
+
+.. class:: IMAP4_stream(command)
+
+   This is a subclass derived from :class:`IMAP4` that connects to the
+   ``stdin/stdout`` file descriptors created by passing *command* to
+   ``os.popen2()``.
+
+   .. versionadded:: 2.3
+
+The following utility functions are defined:
+
+
+.. function:: Internaldate2tuple(datestr)
+
+   Converts an IMAP4 INTERNALDATE string to Coordinated Universal Time. Returns a
+   :mod:`time` module tuple.
+
+
+.. function:: Int2AP(num)
+
+   Converts an integer into a string representation using characters from the set
+   [``A`` .. ``P``].
+
+
+.. function:: ParseFlags(flagstr)
+
+   Converts an IMAP4 ``FLAGS`` response to a tuple of individual flags.
+
+
+.. function:: Time2Internaldate(date_time)
+
+   Converts a :mod:`time` module tuple to an IMAP4 ``INTERNALDATE`` representation.
+   Returns a string in the form: ``"DD-Mmm-YYYY HH:MM:SS +HHMM"`` (including
+   double-quotes).
+
+Note that IMAP4 message numbers change as the mailbox changes; in particular,
+after an ``EXPUNGE`` command performs deletions the remaining messages are
+renumbered. So it is highly advisable to use UIDs instead, with the UID command.
+
+At the end of the module, there is a test section that contains a more extensive
+example of usage.
+
+
+.. seealso::
+
+   Documents describing the protocol, and sources and binaries  for servers
+   implementing it, can all be found at the University of Washington's *IMAP
+   Information Center* (http://www.cac.washington.edu/imap/).
+
+
+.. _imap4-objects:
+
+IMAP4 Objects
+-------------
+
+All IMAP4rev1 commands are represented by methods of the same name, either
+upper-case or lower-case.
+
+All arguments to commands are converted to strings, except for ``AUTHENTICATE``,
+and the last argument to ``APPEND`` which is passed as an IMAP4 literal.  If
+necessary (the string contains IMAP4 protocol-sensitive characters and isn't
+enclosed with either parentheses or double quotes) each string is quoted.
+However, the *password* argument to the ``LOGIN`` command is always quoted. If
+you want to avoid having an argument string quoted (eg: the *flags* argument to
+``STORE``) then enclose the string in parentheses (eg: ``r'(\Deleted)'``).
+
+Each command returns a tuple: ``(type, [data, ...])`` where *type* is usually
+``'OK'`` or ``'NO'``, and *data* is either the text from the command response,
+or mandated results from the command. Each *data* is either a string, or a
+tuple. If a tuple, then the first part is the header of the response, and the
+second part contains the data (ie: 'literal' value).
+
+The *message_set* options to commands below is a string specifying one or more
+messages to be acted upon.  It may be a simple message number (``'1'``), a range
+of message numbers (``'2:4'``), or a group of non-contiguous ranges separated by
+commas (``'1:3,6:9'``).  A range can contain an asterisk to indicate an infinite
+upper bound (``'3:*'``).
+
+An :class:`IMAP4` instance has the following methods:
+
+
+.. method:: IMAP4.append(mailbox, flags, date_time, message)
+
+   Append *message* to named mailbox.
+
+
+.. method:: IMAP4.authenticate(mechanism, authobject)
+
+   Authenticate command --- requires response processing.
+
+   *mechanism* specifies which authentication mechanism is to be used - it should
+   appear in the instance variable ``capabilities`` in the form ``AUTH=mechanism``.
+
+   *authobject* must be a callable object::
+
+      data = authobject(response)
+
+   It will be called to process server continuation responses. It should return
+   ``data`` that will be encoded and sent to server. It should return ``None`` if
+   the client abort response ``*`` should be sent instead.
+
+
+.. method:: IMAP4.check()
+
+   Checkpoint mailbox on server.
+
+
+.. method:: IMAP4.close()
+
+   Close currently selected mailbox. Deleted messages are removed from writable
+   mailbox. This is the recommended command before ``LOGOUT``.
+
+
+.. method:: IMAP4.copy(message_set, new_mailbox)
+
+   Copy *message_set* messages onto end of *new_mailbox*.
+
+
+.. method:: IMAP4.create(mailbox)
+
+   Create new mailbox named *mailbox*.
+
+
+.. method:: IMAP4.delete(mailbox)
+
+   Delete old mailbox named *mailbox*.
+
+
+.. method:: IMAP4.deleteacl(mailbox, who)
+
+   Delete the ACLs (remove any rights) set for who on mailbox.
+
+   .. versionadded:: 2.4
+
+
+.. method:: IMAP4.expunge()
+
+   Permanently remove deleted items from selected mailbox. Generates an ``EXPUNGE``
+   response for each deleted message. Returned data contains a list of ``EXPUNGE``
+   message numbers in order received.
+
+
+.. method:: IMAP4.fetch(message_set, message_parts)
+
+   Fetch (parts of) messages.  *message_parts* should be a string of message part
+   names enclosed within parentheses, eg: ``"(UID BODY[TEXT])"``.  Returned data
+   are tuples of message part envelope and data.
+
+
+.. method:: IMAP4.getacl(mailbox)
+
+   Get the ``ACL``\ s for *mailbox*. The method is non-standard, but is supported
+   by the ``Cyrus`` server.
+
+
+.. method:: IMAP4.getannotation(mailbox, entry, attribute)
+
+   Retrieve the specified ``ANNOTATION``\ s for *mailbox*. The method is
+   non-standard, but is supported by the ``Cyrus`` server.
+
+   .. versionadded:: 2.5
+
+
+.. method:: IMAP4.getquota(root)
+
+   Get the ``quota`` *root*'s resource usage and limits. This method is part of the
+   IMAP4 QUOTA extension defined in rfc2087.
+
+   .. versionadded:: 2.3
+
+
+.. method:: IMAP4.getquotaroot(mailbox)
+
+   Get the list of ``quota`` ``roots`` for the named *mailbox*. This method is part
+   of the IMAP4 QUOTA extension defined in rfc2087.
+
+   .. versionadded:: 2.3
+
+
+.. method:: IMAP4.list([directory[, pattern]])
+
+   List mailbox names in *directory* matching *pattern*.  *directory* defaults to
+   the top-level mail folder, and *pattern* defaults to match anything.  Returned
+   data contains a list of ``LIST`` responses.
+
+
+.. method:: IMAP4.login(user, password)
+
+   Identify the client using a plaintext password. The *password* will be quoted.
+
+
+.. method:: IMAP4.login_cram_md5(user, password)
+
+   Force use of ``CRAM-MD5`` authentication when identifying the client to protect
+   the password.  Will only work if the server ``CAPABILITY`` response includes the
+   phrase ``AUTH=CRAM-MD5``.
+
+   .. versionadded:: 2.3
+
+
+.. method:: IMAP4.logout()
+
+   Shutdown connection to server. Returns server ``BYE`` response.
+
+
+.. method:: IMAP4.lsub([directory[, pattern]])
+
+   List subscribed mailbox names in directory matching pattern. *directory*
+   defaults to the top level directory and *pattern* defaults to match any mailbox.
+   Returned data are tuples of message part envelope and data.
+
+
+.. method:: IMAP4.myrights(mailbox)
+
+   Show my ACLs for a mailbox (i.e. the rights that I have on mailbox).
+
+   .. versionadded:: 2.4
+
+
+.. method:: IMAP4.namespace()
+
+   Returns IMAP namespaces as defined in RFC2342.
+
+   .. versionadded:: 2.3
+
+
+.. method:: IMAP4.noop()
+
+   Send ``NOOP`` to server.
+
+
+.. method:: IMAP4.open(host, port)
+
+   Opens socket to *port* at *host*. The connection objects established by this
+   method will be used in the ``read``, ``readline``, ``send``, and ``shutdown``
+   methods. You may override this method.
+
+
+.. method:: IMAP4.partial(message_num, message_part, start, length)
+
+   Fetch truncated part of a message. Returned data is a tuple of message part
+   envelope and data.
+
+
+.. method:: IMAP4.proxyauth(user)
+
+   Assume authentication as *user*. Allows an authorised administrator to proxy
+   into any user's mailbox.
+
+   .. versionadded:: 2.3
+
+
+.. method:: IMAP4.read(size)
+
+   Reads *size* bytes from the remote server. You may override this method.
+
+
+.. method:: IMAP4.readline()
+
+   Reads one line from the remote server. You may override this method.
+
+
+.. method:: IMAP4.recent()
+
+   Prompt server for an update. Returned data is ``None`` if no new messages, else
+   value of ``RECENT`` response.
+
+
+.. method:: IMAP4.rename(oldmailbox, newmailbox)
+
+   Rename mailbox named *oldmailbox* to *newmailbox*.
+
+
+.. method:: IMAP4.response(code)
+
+   Return data for response *code* if received, or ``None``. Returns the given
+   code, instead of the usual type.
+
+
+.. method:: IMAP4.search(charset, criterion[, ...])
+
+   Search mailbox for matching messages.  *charset* may be ``None``, in which case
+   no ``CHARSET`` will be specified in the request to the server.  The IMAP
+   protocol requires that at least one criterion be specified; an exception will be
+   raised when the server returns an error.
+
+   Example::
+
+      # M is a connected IMAP4 instance...
+      typ, msgnums = M.search(None, 'FROM', '"LDJ"')
+
+      # or:
+      typ, msgnums = M.search(None, '(FROM "LDJ")')
+
+
+.. method:: IMAP4.select([mailbox[, readonly]])
+
+   Select a mailbox. Returned data is the count of messages in *mailbox*
+   (``EXISTS`` response).  The default *mailbox* is ``'INBOX'``.  If the *readonly*
+   flag is set, modifications to the mailbox are not allowed.
+
+
+.. method:: IMAP4.send(data)
+
+   Sends ``data`` to the remote server. You may override this method.
+
+
+.. method:: IMAP4.setacl(mailbox, who, what)
+
+   Set an ``ACL`` for *mailbox*. The method is non-standard, but is supported by
+   the ``Cyrus`` server.
+
+
+.. method:: IMAP4.setannotation(mailbox, entry, attribute[, ...])
+
+   Set ``ANNOTATION``\ s for *mailbox*. The method is non-standard, but is
+   supported by the ``Cyrus`` server.
+
+   .. versionadded:: 2.5
+
+
+.. method:: IMAP4.setquota(root, limits)
+
+   Set the ``quota`` *root*'s resource *limits*. This method is part of the IMAP4
+   QUOTA extension defined in rfc2087.
+
+   .. versionadded:: 2.3
+
+
+.. method:: IMAP4.shutdown()
+
+   Close connection established in ``open``. You may override this method.
+
+
+.. method:: IMAP4.socket()
+
+   Returns socket instance used to connect to server.
+
+
+.. method:: IMAP4.sort(sort_criteria, charset, search_criterion[, ...])
+
+   The ``sort`` command is a variant of ``search`` with sorting semantics for the
+   results.  Returned data contains a space separated list of matching message
+   numbers.
+
+   Sort has two arguments before the *search_criterion* argument(s); a
+   parenthesized list of *sort_criteria*, and the searching *charset*.  Note that
+   unlike ``search``, the searching *charset* argument is mandatory.  There is also
+   a ``uid sort`` command which corresponds to ``sort`` the way that ``uid search``
+   corresponds to ``search``.  The ``sort`` command first searches the mailbox for
+   messages that match the given searching criteria using the charset argument for
+   the interpretation of strings in the searching criteria.  It then returns the
+   numbers of matching messages.
+
+   This is an ``IMAP4rev1`` extension command.
+
+
+.. method:: IMAP4.status(mailbox, names)
+
+   Request named status conditions for *mailbox*.
+
+
+.. method:: IMAP4.store(message_set, command, flag_list)
+
+   Alters flag dispositions for messages in mailbox.  *command* is specified by
+   section 6.4.6 of :rfc:`2060` as being one of "FLAGS", "+FLAGS", or "-FLAGS",
+   optionally with a suffix of ".SILENT".
+
+   For example, to set the delete flag on all messages::
+
+      typ, data = M.search(None, 'ALL')
+      for num in data[0].split():
+         M.store(num, '+FLAGS', '\\Deleted')
+      M.expunge()
+
+
+.. method:: IMAP4.subscribe(mailbox)
+
+   Subscribe to new mailbox.
+
+
+.. method:: IMAP4.thread(threading_algorithm, charset, search_criterion[, ...])
+
+   The ``thread`` command is a variant of ``search`` with threading semantics for
+   the results.  Returned data contains a space separated list of thread members.
+
+   Thread members consist of zero or more messages numbers, delimited by spaces,
+   indicating successive parent and child.
+
+   Thread has two arguments before the *search_criterion* argument(s); a
+   *threading_algorithm*, and the searching *charset*.  Note that unlike
+   ``search``, the searching *charset* argument is mandatory.  There is also a
+   ``uid thread`` command which corresponds to ``thread`` the way that ``uid
+   search`` corresponds to ``search``.  The ``thread`` command first searches the
+   mailbox for messages that match the given searching criteria using the charset
+   argument for the interpretation of strings in the searching criteria. It then
+   returns the matching messages threaded according to the specified threading
+   algorithm.
+
+   This is an ``IMAP4rev1`` extension command.
+
+   .. versionadded:: 2.4
+
+
+.. method:: IMAP4.uid(command, arg[, ...])
+
+   Execute command args with messages identified by UID, rather than message
+   number.  Returns response appropriate to command.  At least one argument must be
+   supplied; if none are provided, the server will return an error and an exception
+   will be raised.
+
+
+.. method:: IMAP4.unsubscribe(mailbox)
+
+   Unsubscribe from old mailbox.
+
+
+.. method:: IMAP4.xatom(name[, arg[, ...]])
+
+   Allow simple extension commands notified by server in ``CAPABILITY`` response.
+
+Instances of :class:`IMAP4_SSL` have just one additional method:
+
+
+.. method:: IMAP4_SSL.ssl()
+
+   Returns SSLObject instance used for the secure connection with the server.
+
+The following attributes are defined on instances of :class:`IMAP4`:
+
+
+.. attribute:: IMAP4.PROTOCOL_VERSION
+
+   The most recent supported protocol in the ``CAPABILITY`` response from the
+   server.
+
+
+.. attribute:: IMAP4.debug
+
+   Integer value to control debugging output.  The initialize value is taken from
+   the module variable ``Debug``.  Values greater than three trace each command.
+
+
+.. _imap4-example:
+
+IMAP4 Example
+-------------
+
+Here is a minimal example (without error checking) that opens a mailbox and
+retrieves and prints all messages::
+
+   import getpass, imaplib
+
+   M = imaplib.IMAP4()
+   M.login(getpass.getuser(), getpass.getpass())
+   M.select()
+   typ, data = M.search(None, 'ALL')
+   for num in data[0].split():
+       typ, data = M.fetch(num, '(RFC822)')
+       print 'Message %s\n%s\n' % (num, data[0][1])
+   M.close()
+   M.logout()
+
diff --git a/Doc/library/imghdr.rst b/Doc/library/imghdr.rst
new file mode 100644
index 0000000..90a8304
--- /dev/null
+++ b/Doc/library/imghdr.rst
@@ -0,0 +1,71 @@
+
+:mod:`imghdr` --- Determine the type of an image
+================================================
+
+.. module:: imghdr
+   :synopsis: Determine the type of image contained in a file or byte stream.
+
+
+The :mod:`imghdr` module determines the type of image contained in a file or
+byte stream.
+
+The :mod:`imghdr` module defines the following function:
+
+
+.. function:: what(filename[, h])
+
+   Tests the image data contained in the file named by *filename*, and returns a
+   string describing the image type.  If optional *h* is provided, the *filename*
+   is ignored and *h* is assumed to contain the byte stream to test.
+
+The following image types are recognized, as listed below with the return value
+from :func:`what`:
+
++------------+-----------------------------------+
+| Value      | Image format                      |
++============+===================================+
+| ``'rgb'``  | SGI ImgLib Files                  |
++------------+-----------------------------------+
+| ``'gif'``  | GIF 87a and 89a Files             |
++------------+-----------------------------------+
+| ``'pbm'``  | Portable Bitmap Files             |
++------------+-----------------------------------+
+| ``'pgm'``  | Portable Graymap Files            |
++------------+-----------------------------------+
+| ``'ppm'``  | Portable Pixmap Files             |
++------------+-----------------------------------+
+| ``'tiff'`` | TIFF Files                        |
++------------+-----------------------------------+
+| ``'rast'`` | Sun Raster Files                  |
++------------+-----------------------------------+
+| ``'xbm'``  | X Bitmap Files                    |
++------------+-----------------------------------+
+| ``'jpeg'`` | JPEG data in JFIF or Exif formats |
++------------+-----------------------------------+
+| ``'bmp'``  | BMP files                         |
++------------+-----------------------------------+
+| ``'png'``  | Portable Network Graphics         |
++------------+-----------------------------------+
+
+.. versionadded:: 2.5
+   Exif detection.
+
+You can extend the list of file types :mod:`imghdr` can recognize by appending
+to this variable:
+
+
+.. data:: tests
+
+   A list of functions performing the individual tests.  Each function takes two
+   arguments: the byte-stream and an open file-like object. When :func:`what` is
+   called with a byte-stream, the file-like object will be ``None``.
+
+   The test function should return a string describing the image type if the test
+   succeeded, or ``None`` if it failed.
+
+Example::
+
+   >>> import imghdr
+   >>> imghdr.what('/tmp/bass.gif')
+   'gif'
+
diff --git a/Doc/library/imp.rst b/Doc/library/imp.rst
new file mode 100644
index 0000000..f80bea3
--- /dev/null
+++ b/Doc/library/imp.rst
@@ -0,0 +1,298 @@
+
+:mod:`imp` --- Access the :keyword:`import` internals
+=====================================================
+
+.. module:: imp
+   :synopsis: Access the implementation of the import statement.
+
+
+.. index:: statement: import
+
+This module provides an interface to the mechanisms used to implement the
+:keyword:`import` statement.  It defines the following constants and functions:
+
+
+.. function:: get_magic()
+
+   .. index:: pair: file; byte-code
+
+   Return the magic string value used to recognize byte-compiled code files
+   (:file:`.pyc` files).  (This value may be different for each Python version.)
+
+
+.. function:: get_suffixes()
+
+   Return a list of triples, each describing a particular type of module. Each
+   triple has the form ``(suffix, mode, type)``, where *suffix* is a string to be
+   appended to the module name to form the filename to search for, *mode* is the
+   mode string to pass to the built-in :func:`open` function to open the file (this
+   can be ``'r'`` for text files or ``'rb'`` for binary files), and *type* is the
+   file type, which has one of the values :const:`PY_SOURCE`, :const:`PY_COMPILED`,
+   or :const:`C_EXTENSION`, described below.
+
+
+.. function:: find_module(name[, path])
+
+   Try to find the module *name* on the search path *path*.  If *path* is a list of
+   directory names, each directory is searched for files with any of the suffixes
+   returned by :func:`get_suffixes` above.  Invalid names in the list are silently
+   ignored (but all list items must be strings).  If *path* is omitted or ``None``,
+   the list of directory names given by ``sys.path`` is searched, but first it
+   searches a few special places: it tries to find a built-in module with the given
+   name (:const:`C_BUILTIN`), then a frozen module (:const:`PY_FROZEN`), and on
+   some systems some other places are looked in as well (on the Mac, it looks for a
+   resource (:const:`PY_RESOURCE`); on Windows, it looks in the registry which may
+   point to a specific file).
+
+   If search is successful, the return value is a triple ``(file, pathname,
+   description)`` where *file* is an open file object positioned at the beginning,
+   *pathname* is the pathname of the file found, and *description* is a triple as
+   contained in the list returned by :func:`get_suffixes` describing the kind of
+   module found. If the module does not live in a file, the returned *file* is
+   ``None``, *filename* is the empty string, and the *description* tuple contains
+   empty strings for its suffix and mode; the module type is as indicate in
+   parentheses above.  If the search is unsuccessful, :exc:`ImportError` is raised.
+   Other exceptions indicate problems with the arguments or environment.
+
+   This function does not handle hierarchical module names (names containing dots).
+   In order to find *P*.*M*, that is, submodule *M* of package *P*, use
+   :func:`find_module` and :func:`load_module` to find and load package *P*, and
+   then use :func:`find_module` with the *path* argument set to ``P.__path__``.
+   When *P* itself has a dotted name, apply this recipe recursively.
+
+
+.. function:: load_module(name, file, filename, description)
+
+   Load a module that was previously found by :func:`find_module` (or by an
+   otherwise conducted search yielding compatible results).  This function does
+   more than importing the module: if the module was already imported, it will
+   reload the module! The *name* argument indicates the full module name (including
+   the package name, if this is a submodule of a package).  The *file* argument is
+   an open file, and *filename* is the corresponding file name; these can be
+   ``None`` and ``''``, respectively, when the module is not being loaded from a
+   file.  The *description* argument is a tuple, as would be returned by
+   :func:`get_suffixes`, describing what kind of module must be loaded.
+
+   If the load is successful, the return value is the module object; otherwise, an
+   exception (usually :exc:`ImportError`) is raised.
+
+   **Important:** the caller is responsible for closing the *file* argument, if it
+   was not ``None``, even when an exception is raised.  This is best done using a
+   :keyword:`try` ... :keyword:`finally` statement.
+
+
+.. function:: new_module(name)
+
+   Return a new empty module object called *name*.  This object is *not* inserted
+   in ``sys.modules``.
+
+
+.. function:: lock_held()
+
+   Return ``True`` if the import lock is currently held, else ``False``. On
+   platforms without threads, always return ``False``.
+
+   On platforms with threads, a thread executing an import holds an internal lock
+   until the import is complete. This lock blocks other threads from doing an
+   import until the original import completes, which in turn prevents other threads
+   from seeing incomplete module objects constructed by the original thread while
+   in the process of completing its import (and the imports, if any, triggered by
+   that).
+
+
+.. function:: acquire_lock()
+
+   Acquires the interpreter's import lock for the current thread.  This lock should
+   be used by import hooks to ensure thread-safety when importing modules. On
+   platforms without threads, this function does nothing.
+
+   .. versionadded:: 2.3
+
+
+.. function:: release_lock()
+
+   Release the interpreter's import lock. On platforms without threads, this
+   function does nothing.
+
+   .. versionadded:: 2.3
+
+The following constants with integer values, defined in this module, are used to
+indicate the search result of :func:`find_module`.
+
+
+.. data:: PY_SOURCE
+
+   The module was found as a source file.
+
+
+.. data:: PY_COMPILED
+
+   The module was found as a compiled code object file.
+
+
+.. data:: C_EXTENSION
+
+   The module was found as dynamically loadable shared library.
+
+
+.. data:: PY_RESOURCE
+
+   The module was found as a Mac OS 9 resource.  This value can only be returned on
+   a Mac OS 9 or earlier Macintosh.
+
+
+.. data:: PKG_DIRECTORY
+
+   The module was found as a package directory.
+
+
+.. data:: C_BUILTIN
+
+   The module was found as a built-in module.
+
+
+.. data:: PY_FROZEN
+
+   The module was found as a frozen module (see :func:`init_frozen`).
+
+The following constant and functions are obsolete; their functionality is
+available through :func:`find_module` or :func:`load_module`. They are kept
+around for backward compatibility:
+
+
+.. data:: SEARCH_ERROR
+
+   Unused.
+
+
+.. function:: init_builtin(name)
+
+   Initialize the built-in module called *name* and return its module object along
+   with storing it in ``sys.modules``.  If the module was already initialized, it
+   will be initialized *again*.  Re-initialization involves the copying of the
+   built-in module's ``__dict__`` from the cached module over the module's entry in
+   ``sys.modules``.  If there is no built-in module called *name*, ``None`` is
+   returned.
+
+
+.. function:: init_frozen(name)
+
+   Initialize the frozen module called *name* and return its module object.  If
+   the module was already initialized, it will be initialized *again*.  If there
+   is no frozen module called *name*, ``None`` is returned.  (Frozen modules are
+   modules written in Python whose compiled byte-code object is incorporated
+   into a custom-built Python interpreter by Python's :program:`freeze`
+   utility. See :file:`Tools/freeze/` for now.)
+
+
+.. function:: is_builtin(name)
+
+   Return ``1`` if there is a built-in module called *name* which can be
+   initialized again.  Return ``-1`` if there is a built-in module called *name*
+   which cannot be initialized again (see :func:`init_builtin`).  Return ``0`` if
+   there is no built-in module called *name*.
+
+
+.. function:: is_frozen(name)
+
+   Return ``True`` if there is a frozen module (see :func:`init_frozen`) called
+   *name*, or ``False`` if there is no such module.
+
+
+.. function:: load_compiled(name, pathname, [file])
+
+   .. index:: pair: file; byte-code
+
+   Load and initialize a module implemented as a byte-compiled code file and return
+   its module object.  If the module was already initialized, it will be
+   initialized *again*.  The *name* argument is used to create or access a module
+   object.  The *pathname* argument points to the byte-compiled code file.  The
+   *file* argument is the byte-compiled code file, open for reading in binary mode,
+   from the beginning. It must currently be a real file object, not a user-defined
+   class emulating a file.
+
+
+.. function:: load_dynamic(name, pathname[, file])
+
+   Load and initialize a module implemented as a dynamically loadable shared
+   library and return its module object.  If the module was already initialized, it
+   will be initialized *again*. Re-initialization involves copying the ``__dict__``
+   attribute of the cached instance of the module over the value used in the module
+   cached in ``sys.modules``.  The *pathname* argument must point to the shared
+   library.  The *name* argument is used to construct the name of the
+   initialization function: an external C function called ``initname()`` in the
+   shared library is called.  The optional *file* argument is ignored.  (Note:
+   using shared libraries is highly system dependent, and not all systems support
+   it.)
+
+
+.. function:: load_source(name, pathname[, file])
+
+   Load and initialize a module implemented as a Python source file and return its
+   module object.  If the module was already initialized, it will be initialized
+   *again*.  The *name* argument is used to create or access a module object.  The
+   *pathname* argument points to the source file.  The *file* argument is the
+   source file, open for reading as text, from the beginning. It must currently be
+   a real file object, not a user-defined class emulating a file.  Note that if a
+   properly matching byte-compiled file (with suffix :file:`.pyc` or :file:`.pyo`)
+   exists, it will be used instead of parsing the given source file.
+
+
+.. class:: NullImporter(path_string)
+
+   The :class:`NullImporter` type is a :pep:`302` import hook that handles
+   non-directory path strings by failing to find any modules.  Calling this type
+   with an existing directory or empty string raises :exc:`ImportError`.
+   Otherwise, a :class:`NullImporter` instance is returned.
+
+   Python adds instances of this type to ``sys.path_importer_cache`` for any path
+   entries that are not directories and are not handled by any other path hooks on
+   ``sys.path_hooks``.  Instances have only one method:
+
+
+   .. method:: NullImporter.find_module(fullname [, path])
+
+      This method always returns ``None``, indicating that the requested module could
+      not be found.
+
+   .. versionadded:: 2.5
+
+
+.. _examples-imp:
+
+Examples
+--------
+
+The following function emulates what was the standard import statement up to
+Python 1.4 (no hierarchical module names).  (This *implementation* wouldn't work
+in that version, since :func:`find_module` has been extended and
+:func:`load_module` has been added in 1.4.) ::
+
+   import imp
+   import sys
+
+   def __import__(name, globals=None, locals=None, fromlist=None):
+       # Fast path: see if the module has already been imported.
+       try:
+           return sys.modules[name]
+       except KeyError:
+           pass
+
+       # If any of the following calls raises an exception,
+       # there's a problem we can't handle -- let the caller handle it.
+
+       fp, pathname, description = imp.find_module(name)
+
+       try:
+           return imp.load_module(name, fp, pathname, description)
+       finally:
+           # Since we may exit via an exception, close fp explicitly.
+           if fp:
+               fp.close()
+
+.. index:: module: knee
+
+A more complete example that implements hierarchical module names and includes a
+:func:`reload` function can be found in the module :mod:`knee`.  The :mod:`knee`
+module can be found in :file:`Demo/imputil/` in the Python source distribution.
+
diff --git a/Doc/library/index.rst b/Doc/library/index.rst
new file mode 100644
index 0000000..1e872ac
--- /dev/null
+++ b/Doc/library/index.rst
@@ -0,0 +1,81 @@
+.. _library-index:
+
+###############################
+  The Python Standard Library
+###############################
+
+:Release: |version|
+:Date: |today|
+
+While the :ref:`reference-index` describes the exact syntax and
+semantics of the Python language, this library reference manual
+describes the standard library that is distributed with Python. It also
+describes some of the optional components that are commonly included
+in Python distributions.
+
+Python's standard library is very extensive, offering a wide range of
+facilities as indicated by the long table of contents listed below. The
+library contains built-in modules (written in C) that provide access to
+system functionality such as file I/O that would otherwise be
+inaccessible to Python programmers, as well as modules written in Python
+that provide standardized solutions for many problems that occur in
+everyday programming. Some of these modules are explicitly designed to
+encourage and enhance the portability of Python programs by abstracting
+away platform-specifics into platform-neutral APIs.
+
+The Python installers for the Windows and Mac platforms usually include
+the entire standard library and often also include many additional
+components. For Unix-like operating systems Python is normally provided
+as a collection of packages, so it may be necessary to use the packaging
+tools provided with the operating system to obtain some or all of the
+optional components.
+
+In addition to the standard library, there is a growing collection of
+over 2500 additional components available from the `Python Package Index
+`_.
+
+
+.. toctree::
+   :maxdepth: 2
+
+   intro.rst
+   functions.rst
+   constants.rst
+   objects.rst
+   stdtypes.rst
+   exceptions.rst
+
+   strings.rst
+   datatypes.rst
+   numeric.rst
+   filesys.rst
+   persistence.rst
+   archiving.rst
+   fileformats.rst
+   crypto.rst
+   allos.rst
+   someos.rst
+   ipc.rst
+   netdata.rst
+   markup.rst
+   internet.rst
+   mm.rst
+   i18n.rst
+   frameworks.rst
+   tk.rst
+   development.rst
+   pdb.rst
+   profile.rst
+   hotshot.rst
+   timeit.rst
+   trace.rst
+   python.rst
+   custominterp.rst
+   modules.rst
+   language.rst
+   misc.rst
+   windows.rst
+   unix.rst
+   mac.rst
+   macosa.rst
+   undoc.rst
diff --git a/Doc/library/inspect.rst b/Doc/library/inspect.rst
new file mode 100644
index 0000000..edec9d5
--- /dev/null
+++ b/Doc/library/inspect.rst
@@ -0,0 +1,507 @@
+
+:mod:`inspect` --- Inspect live objects
+=======================================
+
+.. module:: inspect
+   :synopsis: Extract information and source code from live objects.
+.. moduleauthor:: Ka-Ping Yee 
+.. sectionauthor:: Ka-Ping Yee 
+
+
+.. versionadded:: 2.1
+
+The :mod:`inspect` module provides several useful functions to help get
+information about live objects such as modules, classes, methods, functions,
+tracebacks, frame objects, and code objects.  For example, it can help you
+examine the contents of a class, retrieve the source code of a method, extract
+and format the argument list for a function, or get all the information you need
+to display a detailed traceback.
+
+There are four main kinds of services provided by this module: type checking,
+getting source code, inspecting classes and functions, and examining the
+interpreter stack.
+
+
+.. _inspect-types:
+
+Types and members
+-----------------
+
+The :func:`getmembers` function retrieves the members of an object such as a
+class or module. The eleven functions whose names begin with "is" are mainly
+provided as convenient choices for the second argument to :func:`getmembers`.
+They also help you determine when you can expect to find the following special
+attributes:
+
++-----------+-----------------+---------------------------+-------+
+| Type      | Attribute       | Description               | Notes |
++===========+=================+===========================+=======+
+| module    | __doc__         | documentation string      |       |
++-----------+-----------------+---------------------------+-------+
+|           | __file__        | filename (missing for     |       |
+|           |                 | built-in modules)         |       |
++-----------+-----------------+---------------------------+-------+
+| class     | __doc__         | documentation string      |       |
++-----------+-----------------+---------------------------+-------+
+|           | __module__      | name of module in which   |       |
+|           |                 | this class was defined    |       |
++-----------+-----------------+---------------------------+-------+
+| method    | __doc__         | documentation string      |       |
++-----------+-----------------+---------------------------+-------+
+|           | __name__        | name with which this      |       |
+|           |                 | method was defined        |       |
++-----------+-----------------+---------------------------+-------+
+|           | im_class        | class object that asked   | \(1)  |
+|           |                 | for this method           |       |
++-----------+-----------------+---------------------------+-------+
+|           | im_func         | function object           |       |
+|           |                 | containing implementation |       |
+|           |                 | of method                 |       |
++-----------+-----------------+---------------------------+-------+
+|           | im_self         | instance to which this    |       |
+|           |                 | method is bound, or       |       |
+|           |                 | ``None``                  |       |
++-----------+-----------------+---------------------------+-------+
+| function  | __doc__         | documentation string      |       |
++-----------+-----------------+---------------------------+-------+
+|           | __name__        | name with which this      |       |
+|           |                 | function was defined      |       |
++-----------+-----------------+---------------------------+-------+
+|           | __code__        | code object containing    |       |
+|           |                 | compiled function         |       |
+|           |                 | bytecode                  |       |
++-----------+-----------------+---------------------------+-------+
+|           | __defaults__    | tuple of any default      |       |
+|           |                 | values for arguments      |       |
++-----------+-----------------+---------------------------+-------+
+|           | __globals__     | global namespace in which |       |
+|           |                 | this function was defined |       |
++-----------+-----------------+---------------------------+-------+
+| traceback | tb_frame        | frame object at this      |       |
+|           |                 | level                     |       |
++-----------+-----------------+---------------------------+-------+
+|           | tb_lasti        | index of last attempted   |       |
+|           |                 | instruction in bytecode   |       |
++-----------+-----------------+---------------------------+-------+
+|           | tb_lineno       | current line number in    |       |
+|           |                 | Python source code        |       |
++-----------+-----------------+---------------------------+-------+
+|           | tb_next         | next inner traceback      |       |
+|           |                 | object (called by this    |       |
+|           |                 | level)                    |       |
++-----------+-----------------+---------------------------+-------+
+| frame     | f_back          | next outer frame object   |       |
+|           |                 | (this frame's caller)     |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_builtins      | built-in namespace seen   |       |
+|           |                 | by this frame             |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_code          | code object being         |       |
+|           |                 | executed in this frame    |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_exc_traceback | traceback if raised in    |       |
+|           |                 | this frame, or ``None``   |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_exc_type      | exception type if raised  |       |
+|           |                 | in this frame, or         |       |
+|           |                 | ``None``                  |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_exc_value     | exception value if raised |       |
+|           |                 | in this frame, or         |       |
+|           |                 | ``None``                  |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_globals       | global namespace seen by  |       |
+|           |                 | this frame                |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_lasti         | index of last attempted   |       |
+|           |                 | instruction in bytecode   |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_lineno        | current line number in    |       |
+|           |                 | Python source code        |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_locals        | local namespace seen by   |       |
+|           |                 | this frame                |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_restricted    | 0 or 1 if frame is in     |       |
+|           |                 | restricted execution mode |       |
++-----------+-----------------+---------------------------+-------+
+|           | f_trace         | tracing function for this |       |
+|           |                 | frame, or ``None``        |       |
++-----------+-----------------+---------------------------+-------+
+| code      | co_argcount     | number of arguments (not  |       |
+|           |                 | including \* or \*\*      |       |
+|           |                 | args)                     |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_code         | string of raw compiled    |       |
+|           |                 | bytecode                  |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_consts       | tuple of constants used   |       |
+|           |                 | in the bytecode           |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_filename     | name of file in which     |       |
+|           |                 | this code object was      |       |
+|           |                 | created                   |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_firstlineno  | number of first line in   |       |
+|           |                 | Python source code        |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_flags        | bitmap: 1=optimized ``|`` |       |
+|           |                 | 2=newlocals ``|`` 4=\*arg |       |
+|           |                 | ``|`` 8=\*\*arg           |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_lnotab       | encoded mapping of line   |       |
+|           |                 | numbers to bytecode       |       |
+|           |                 | indices                   |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_name         | name with which this code |       |
+|           |                 | object was defined        |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_names        | tuple of names of local   |       |
+|           |                 | variables                 |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_nlocals      | number of local variables |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_stacksize    | virtual machine stack     |       |
+|           |                 | space required            |       |
++-----------+-----------------+---------------------------+-------+
+|           | co_varnames     | tuple of names of         |       |
+|           |                 | arguments and local       |       |
+|           |                 | variables                 |       |
++-----------+-----------------+---------------------------+-------+
+| builtin   | __doc__         | documentation string      |       |
++-----------+-----------------+---------------------------+-------+
+|           | __name__        | original name of this     |       |
+|           |                 | function or method        |       |
++-----------+-----------------+---------------------------+-------+
+|           | __self__        | instance to which a       |       |
+|           |                 | method is bound, or       |       |
+|           |                 | ``None``                  |       |
++-----------+-----------------+---------------------------+-------+
+
+Note:
+
+(1)
+   .. versionchanged:: 2.2
+      :attr:`im_class` used to refer to the class that defined the method.
+
+
+.. function:: getmembers(object[, predicate])
+
+   Return all the members of an object in a list of (name, value) pairs sorted by
+   name.  If the optional *predicate* argument is supplied, only members for which
+   the predicate returns a true value are included.
+
+
+.. function:: getmoduleinfo(path)
+
+   Return a tuple of values that describe how Python will interpret the file
+   identified by *path* if it is a module, or ``None`` if it would not be
+   identified as a module.  The return tuple is ``(name, suffix, mode, mtype)``,
+   where *name* is the name of the module without the name of any enclosing
+   package, *suffix* is the trailing part of the file name (which may not be a
+   dot-delimited extension), *mode* is the :func:`open` mode that would be used
+   (``'r'`` or ``'rb'``), and *mtype* is an integer giving the type of the
+   module.  *mtype* will have a value which can be compared to the constants
+   defined in the :mod:`imp` module; see the documentation for that module for
+   more information on module types.
+
+
+.. function:: getmodulename(path)
+
+   Return the name of the module named by the file *path*, without including the
+   names of enclosing packages.  This uses the same algorithm as the interpreter
+   uses when searching for modules.  If the name cannot be matched according to the
+   interpreter's rules, ``None`` is returned.
+
+
+.. function:: ismodule(object)
+
+   Return true if the object is a module.
+
+
+.. function:: isclass(object)
+
+   Return true if the object is a class.
+
+
+.. function:: ismethod(object)
+
+   Return true if the object is a method.
+
+
+.. function:: isfunction(object)
+
+   Return true if the object is a Python function or unnamed (lambda) function.
+
+
+.. function:: istraceback(object)
+
+   Return true if the object is a traceback.
+
+
+.. function:: isframe(object)
+
+   Return true if the object is a frame.
+
+
+.. function:: iscode(object)
+
+   Return true if the object is a code.
+
+
+.. function:: isbuiltin(object)
+
+   Return true if the object is a built-in function.
+
+
+.. function:: isroutine(object)
+
+   Return true if the object is a user-defined or built-in function or method.
+
+
+.. function:: ismethoddescriptor(object)
+
+   Return true if the object is a method descriptor, but not if ismethod() or
+   isclass() or isfunction() are true.
+
+   This is new as of Python 2.2, and, for example, is true of int.__add__. An
+   object passing this test has a __get__ attribute but not a __set__ attribute,
+   but beyond that the set of attributes varies.  __name__ is usually sensible, and
+   __doc__ often is.
+
+   Methods implemented via descriptors that also pass one of the other tests return
+   false from the ismethoddescriptor() test, simply because the other tests promise
+   more -- you can, e.g., count on having the im_func attribute (etc) when an
+   object passes ismethod().
+
+
+.. function:: isdatadescriptor(object)
+
+   Return true if the object is a data descriptor.
+
+   Data descriptors have both a __get__ and a __set__ attribute.  Examples are
+   properties (defined in Python), getsets, and members.  The latter two are
+   defined in C and there are more specific tests available for those types, which
+   is robust across Python implementations.  Typically, data descriptors will also
+   have __name__ and __doc__ attributes (properties, getsets, and members have both
+   of these attributes), but this is not guaranteed.
+
+   .. versionadded:: 2.3
+
+
+.. function:: isgetsetdescriptor(object)
+
+   Return true if the object is a getset descriptor.
+
+   getsets are attributes defined in extension modules via ``PyGetSetDef``
+   structures.  For Python implementations without such types, this method will
+   always return ``False``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: ismemberdescriptor(object)
+
+   Return true if the object is a member descriptor.
+
+   Member descriptors are attributes defined in extension modules via
+   ``PyMemberDef`` structures.  For Python implementations without such types, this
+   method will always return ``False``.
+
+   .. versionadded:: 2.5
+
+
+.. _inspect-source:
+
+Retrieving source code
+----------------------
+
+
+.. function:: getdoc(object)
+
+   Get the documentation string for an object. All tabs are expanded to spaces.  To
+   clean up docstrings that are indented to line up with blocks of code, any
+   whitespace than can be uniformly removed from the second line onwards is
+   removed.
+
+
+.. function:: getcomments(object)
+
+   Return in a single string any lines of comments immediately preceding the
+   object's source code (for a class, function, or method), or at the top of the
+   Python source file (if the object is a module).
+
+
+.. function:: getfile(object)
+
+   Return the name of the (text or binary) file in which an object was defined.
+   This will fail with a :exc:`TypeError` if the object is a built-in module,
+   class, or function.
+
+
+.. function:: getmodule(object)
+
+   Try to guess which module an object was defined in.
+
+
+.. function:: getsourcefile(object)
+
+   Return the name of the Python source file in which an object was defined.  This
+   will fail with a :exc:`TypeError` if the object is a built-in module, class, or
+   function.
+
+
+.. function:: getsourcelines(object)
+
+   Return a list of source lines and starting line number for an object. The
+   argument may be a module, class, method, function, traceback, frame, or code
+   object.  The source code is returned as a list of the lines corresponding to the
+   object and the line number indicates where in the original source file the first
+   line of code was found.  An :exc:`IOError` is raised if the source code cannot
+   be retrieved.
+
+
+.. function:: getsource(object)
+
+   Return the text of the source code for an object. The argument may be a module,
+   class, method, function, traceback, frame, or code object.  The source code is
+   returned as a single string.  An :exc:`IOError` is raised if the source code
+   cannot be retrieved.
+
+
+.. _inspect-classes-functions:
+
+Classes and functions
+---------------------
+
+
+.. function:: getclasstree(classes[, unique])
+
+   Arrange the given list of classes into a hierarchy of nested lists. Where a
+   nested list appears, it contains classes derived from the class whose entry
+   immediately precedes the list.  Each entry is a 2-tuple containing a class and a
+   tuple of its base classes.  If the *unique* argument is true, exactly one entry
+   appears in the returned structure for each class in the given list.  Otherwise,
+   classes using multiple inheritance and their descendants will appear multiple
+   times.
+
+
+.. function:: getargspec(func)
+
+   Get the names and default values of a function's arguments. A tuple of four
+   things is returned: ``(args, varargs, varkw, defaults)``. *args* is a list of
+   the argument names (it may contain nested lists). *varargs* and *varkw* are the
+   names of the ``*`` and ``**`` arguments or ``None``. *defaults* is a tuple of
+   default argument values or None if there are no default arguments; if this tuple
+   has *n* elements, they correspond to the last *n* elements listed in *args*.
+
+
+.. function:: getargvalues(frame)
+
+   Get information about arguments passed into a particular frame. A tuple of four
+   things is returned: ``(args, varargs, varkw, locals)``. *args* is a list of the
+   argument names (it may contain nested lists). *varargs* and *varkw* are the
+   names of the ``*`` and ``**`` arguments or ``None``. *locals* is the locals
+   dictionary of the given frame.
+
+
+.. function:: formatargspec(args[, varargs, varkw, defaults, formatarg, formatvarargs, formatvarkw, formatvalue, join])
+
+   Format a pretty argument spec from the four values returned by
+   :func:`getargspec`.  The format\* arguments are the corresponding optional
+   formatting functions that are called to turn names and values into strings.
+
+
+.. function:: formatargvalues(args[, varargs, varkw, locals, formatarg, formatvarargs, formatvarkw, formatvalue, join])
+
+   Format a pretty argument spec from the four values returned by
+   :func:`getargvalues`.  The format\* arguments are the corresponding optional
+   formatting functions that are called to turn names and values into strings.
+
+
+.. function:: getmro(cls)
+
+   Return a tuple of class cls's base classes, including cls, in method resolution
+   order.  No class appears more than once in this tuple. Note that the method
+   resolution order depends on cls's type.  Unless a very peculiar user-defined
+   metatype is in use, cls will be the first element of the tuple.
+
+
+.. _inspect-stack:
+
+The interpreter stack
+---------------------
+
+When the following functions return "frame records," each record is a tuple of
+six items: the frame object, the filename, the line number of the current line,
+the function name, a list of lines of context from the source code, and the
+index of the current line within that list.
+
+.. warning::
+
+   Keeping references to frame objects, as found in the first element of the frame
+   records these functions return, can cause your program to create reference
+   cycles.  Once a reference cycle has been created, the lifespan of all objects
+   which can be accessed from the objects which form the cycle can become much
+   longer even if Python's optional cycle detector is enabled.  If such cycles must
+   be created, it is important to ensure they are explicitly broken to avoid the
+   delayed destruction of objects and increased memory consumption which occurs.
+
+   Though the cycle detector will catch these, destruction of the frames (and local
+   variables) can be made deterministic by removing the cycle in a
+   :keyword:`finally` clause.  This is also important if the cycle detector was
+   disabled when Python was compiled or using :func:`gc.disable`.  For example::
+
+      def handle_stackframe_without_leak():
+          frame = inspect.currentframe()
+          try:
+              # do something with the frame
+          finally:
+              del frame
+
+The optional *context* argument supported by most of these functions specifies
+the number of lines of context to return, which are centered around the current
+line.
+
+
+.. function:: getframeinfo(frame[, context])
+
+   Get information about a frame or traceback object.  A 5-tuple is returned, the
+   last five elements of the frame's frame record.
+
+
+.. function:: getouterframes(frame[, context])
+
+   Get a list of frame records for a frame and all outer frames.  These frames
+   represent the calls that lead to the creation of *frame*. The first entry in the
+   returned list represents *frame*; the last entry represents the outermost call
+   on *frame*'s stack.
+
+
+.. function:: getinnerframes(traceback[, context])
+
+   Get a list of frame records for a traceback's frame and all inner frames.  These
+   frames represent calls made as a consequence of *frame*.  The first entry in the
+   list represents *traceback*; the last entry represents where the exception was
+   raised.
+
+
+.. function:: currentframe()
+
+   Return the frame object for the caller's stack frame.
+
+
+.. function:: stack([context])
+
+   Return a list of frame records for the caller's stack.  The first entry in the
+   returned list represents the caller; the last entry represents the outermost
+   call on the stack.
+
+
+.. function:: trace([context])
+
+   Return a list of frame records for the stack between the current frame and the
+   frame in which an exception currently being handled was raised in.  The first
+   entry in the list represents the caller; the last entry represents where the
+   exception was raised.
+
diff --git a/Doc/library/internet.rst b/Doc/library/internet.rst
new file mode 100644
index 0000000..16b0a44
--- /dev/null
+++ b/Doc/library/internet.rst
@@ -0,0 +1,47 @@
+
+.. _internet:
+
+******************************
+Internet Protocols and Support
+******************************
+
+.. index::
+   single: WWW
+   single: Internet
+   single: World Wide Web
+
+.. index:: module: socket
+
+The modules described in this chapter implement Internet protocols and  support
+for related technology.  They are all implemented in Python. Most of these
+modules require the presence of the system-dependent module :mod:`socket`, which
+is currently supported on most popular platforms.  Here is an overview:
+
+
+.. toctree::
+
+   webbrowser.rst
+   cgi.rst
+   cgitb.rst
+   wsgiref.rst
+   urllib.rst
+   urllib2.rst
+   httplib.rst
+   ftplib.rst
+   poplib.rst
+   imaplib.rst
+   nntplib.rst
+   smtplib.rst
+   smtpd.rst
+   telnetlib.rst
+   uuid.rst
+   urlparse.rst
+   socketserver.rst
+   basehttpserver.rst
+   simplehttpserver.rst
+   cgihttpserver.rst
+   cookielib.rst
+   cookie.rst
+   xmlrpclib.rst
+   simplexmlrpcserver.rst
+   docxmlrpcserver.rst
diff --git a/Doc/library/intro.rst b/Doc/library/intro.rst
new file mode 100644
index 0000000..33bdefd
--- /dev/null
+++ b/Doc/library/intro.rst
@@ -0,0 +1,51 @@
+
+.. _library-intro:
+
+************
+Introduction
+************
+
+The "Python library" contains several different kinds of components.
+
+It contains data types that would normally be considered part of the "core" of a
+language, such as numbers and lists.  For these types, the Python language core
+defines the form of literals and places some constraints on their semantics, but
+does not fully define the semantics.  (On the other hand, the language core does
+define syntactic properties like the spelling and priorities of operators.)
+
+The library also contains built-in functions and exceptions --- objects that can
+be used by all Python code without the need of an :keyword:`import` statement.
+Some of these are defined by the core language, but many are not essential for
+the core semantics and are only described here.
+
+The bulk of the library, however, consists of a collection of modules. There are
+many ways to dissect this collection.  Some modules are written in C and built
+in to the Python interpreter; others are written in Python and imported in
+source form.  Some modules provide interfaces that are highly specific to
+Python, like printing a stack trace; some provide interfaces that are specific
+to particular operating systems, such as access to specific hardware; others
+provide interfaces that are specific to a particular application domain, like
+the World Wide Web. Some modules are available in all versions and ports of
+Python; others are only available when the underlying system supports or
+requires them; yet others are available only when a particular configuration
+option was chosen at the time when Python was compiled and installed.
+
+This manual is organized "from the inside out:" it first describes the built-in
+data types, then the built-in functions and exceptions, and finally the modules,
+grouped in chapters of related modules.  The ordering of the chapters as well as
+the ordering of the modules within each chapter is roughly from most relevant to
+least important.
+
+This means that if you start reading this manual from the start, and skip to the
+next chapter when you get bored, you will get a reasonable overview of the
+available modules and application areas that are supported by the Python
+library.  Of course, you don't *have* to read it like a novel --- you can also
+browse the table of contents (in front of the manual), or look for a specific
+function, module or term in the index (in the back).  And finally, if you enjoy
+learning about random subjects, you choose a random page number (see module
+:mod:`random`) and read a section or two.  Regardless of the order in which you
+read the sections of this manual, it helps to start with chapter :ref:`builtin`,
+as the remainder of the manual assumes familiarity with this material.
+
+Let the show begin!
+
diff --git a/Doc/library/ipc.rst b/Doc/library/ipc.rst
new file mode 100644
index 0000000..fd425ed
--- /dev/null
+++ b/Doc/library/ipc.rst
@@ -0,0 +1,24 @@
+
+.. _ipc:
+
+*****************************************
+Interprocess Communication and Networking
+*****************************************
+
+The modules described in this chapter provide mechanisms for different processes
+to communicate.
+
+Some modules only work for two processes that are on the same machine, e.g.
+:mod:`signal` and :mod:`subprocess`.  Other modules support networking protocols
+that two or more processes can used to communicate across machines.
+
+The list of modules described in this chapter is:
+
+
+.. toctree::
+
+   subprocess.rst
+   socket.rst
+   signal.rst
+   asyncore.rst
+   asynchat.rst
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst
new file mode 100644
index 0000000..9f9cb24
--- /dev/null
+++ b/Doc/library/itertools.rst
@@ -0,0 +1,547 @@
+
+:mod:`itertools` --- Functions creating iterators for efficient looping
+=======================================================================
+
+.. module:: itertools
+   :synopsis: Functions creating iterators for efficient looping.
+.. moduleauthor:: Raymond Hettinger 
+.. sectionauthor:: Raymond Hettinger 
+
+
+.. versionadded:: 2.3
+
+This module implements a number of iterator building blocks inspired by
+constructs from the Haskell and SML programming languages.  Each has been recast
+in a form suitable for Python.
+
+The module standardizes a core set of fast, memory efficient tools that are
+useful by themselves or in combination.  Standardization helps avoid the
+readability and reliability problems which arise when many different individuals
+create their own slightly varying implementations, each with their own quirks
+and naming conventions.
+
+The tools are designed to combine readily with one another.  This makes it easy
+to construct more specialized tools succinctly and efficiently in pure Python.
+
+For instance, SML provides a tabulation tool: ``tabulate(f)`` which produces a
+sequence ``f(0), f(1), ...``.  This toolbox provides :func:`imap` and
+:func:`count` which can be combined to form ``imap(f, count())`` and produce an
+equivalent result.
+
+Likewise, the functional tools are designed to work well with the high-speed
+functions provided by the :mod:`operator` module.
+
+The module author welcomes suggestions for other basic building blocks to be
+added to future versions of the module.
+
+Whether cast in pure python form or compiled code, tools that use iterators are
+more memory efficient (and faster) than their list based counterparts. Adopting
+the principles of just-in-time manufacturing, they create data when and where
+needed instead of consuming memory with the computer equivalent of "inventory".
+
+The performance advantage of iterators becomes more acute as the number of
+elements increases -- at some point, lists grow large enough to severely impact
+memory cache performance and start running slowly.
+
+
+.. seealso::
+
+   The Standard ML Basis Library, `The Standard ML Basis Library
+   `_.
+
+   Haskell, A Purely Functional Language, `Definition of Haskell and the Standard
+   Libraries `_.
+
+
+.. _itertools-functions:
+
+Itertool functions
+------------------
+
+The following module functions all construct and return iterators. Some provide
+streams of infinite length, so they should only be accessed by functions or
+loops that truncate the stream.
+
+
+.. function:: chain(*iterables)
+
+   Make an iterator that returns elements from the first iterable until it is
+   exhausted, then proceeds to the next iterable, until all of the iterables are
+   exhausted.  Used for treating consecutive sequences as a single sequence.
+   Equivalent to::
+
+      def chain(*iterables):
+          for it in iterables:
+              for element in it:
+                  yield element
+
+
+.. function:: count([n])
+
+   Make an iterator that returns consecutive integers starting with *n*. If not
+   specified *n* defaults to zero.   Does not currently support python long
+   integers.  Often used as an argument to :func:`imap` to generate consecutive
+   data points. Also, used with :func:`izip` to add sequence numbers.  Equivalent
+   to::
+
+      def count(n=0):
+          while True:
+              yield n
+              n += 1
+
+   Note, :func:`count` does not check for overflow and will return negative numbers
+   after exceeding ``sys.maxint``.  This behavior may change in the future.
+
+
+.. function:: cycle(iterable)
+
+   Make an iterator returning elements from the iterable and saving a copy of each.
+   When the iterable is exhausted, return elements from the saved copy.  Repeats
+   indefinitely.  Equivalent to::
+
+      def cycle(iterable):
+          saved = []
+          for element in iterable:
+              yield element
+              saved.append(element)
+          while saved:
+              for element in saved:
+                    yield element
+
+   Note, this member of the toolkit may require significant auxiliary storage
+   (depending on the length of the iterable).
+
+
+.. function:: dropwhile(predicate, iterable)
+
+   Make an iterator that drops elements from the iterable as long as the predicate
+   is true; afterwards, returns every element.  Note, the iterator does not produce
+   *any* output until the predicate first becomes false, so it may have a lengthy
+   start-up time.  Equivalent to::
+
+      def dropwhile(predicate, iterable):
+          iterable = iter(iterable)
+          for x in iterable:
+              if not predicate(x):
+                  yield x
+                  break
+          for x in iterable:
+              yield x
+
+
+.. function:: groupby(iterable[, key])
+
+   Make an iterator that returns consecutive keys and groups from the *iterable*.
+   The *key* is a function computing a key value for each element.  If not
+   specified or is ``None``, *key* defaults to an identity function and returns
+   the element unchanged.  Generally, the iterable needs to already be sorted on
+   the same key function.
+
+   The operation of :func:`groupby` is similar to the ``uniq`` filter in Unix.  It
+   generates a break or new group every time the value of the key function changes
+   (which is why it is usually necessary to have sorted the data using the same key
+   function).  That behavior differs from SQL's GROUP BY which aggregates common
+   elements regardless of their input order.
+
+   The returned group is itself an iterator that shares the underlying iterable
+   with :func:`groupby`.  Because the source is shared, when the :func:`groupby`
+   object is advanced, the previous group is no longer visible.  So, if that data
+   is needed later, it should be stored as a list::
+
+      groups = []
+      uniquekeys = []
+      data = sorted(data, key=keyfunc)
+      for k, g in groupby(data, keyfunc):
+          groups.append(list(g))      # Store group iterator as a list
+          uniquekeys.append(k)
+
+   :func:`groupby` is equivalent to::
+
+      class groupby(object):
+          def __init__(self, iterable, key=None):
+              if key is None:
+                  key = lambda x: x
+              self.keyfunc = key
+              self.it = iter(iterable)
+              self.tgtkey = self.currkey = self.currvalue = []
+          def __iter__(self):
+              return self
+          def __next__(self):
+              while self.currkey == self.tgtkey:
+                  self.currvalue = next(self.it) # Exit on StopIteration
+                  self.currkey = self.keyfunc(self.currvalue)
+              self.tgtkey = self.currkey
+              return (self.currkey, self._grouper(self.tgtkey))
+          def _grouper(self, tgtkey):
+              while self.currkey == tgtkey:
+                  yield self.currvalue
+                  self.currvalue = next(self.it) # Exit on StopIteration
+                  self.currkey = self.keyfunc(self.currvalue)
+
+   .. versionadded:: 2.4
+
+
+.. function:: ifilter(predicate, iterable)
+
+   Make an iterator that filters elements from iterable returning only those for
+   which the predicate is ``True``. If *predicate* is ``None``, return the items
+   that are true. Equivalent to::
+
+      def ifilter(predicate, iterable):
+          if predicate is None:
+              predicate = bool
+          for x in iterable:
+              if predicate(x):
+                  yield x
+
+
+.. function:: ifilterfalse(predicate, iterable)
+
+   Make an iterator that filters elements from iterable returning only those for
+   which the predicate is ``False``. If *predicate* is ``None``, return the items
+   that are false. Equivalent to::
+
+      def ifilterfalse(predicate, iterable):
+          if predicate is None:
+              predicate = bool
+          for x in iterable:
+              if not predicate(x):
+                  yield x
+
+
+.. function:: imap(function, *iterables)
+
+   Make an iterator that computes the function using arguments from each of the
+   iterables.  If *function* is set to ``None``, then :func:`imap` returns the
+   arguments as a tuple.  Like :func:`map` but stops when the shortest iterable is
+   exhausted instead of filling in ``None`` for shorter iterables.  The reason for
+   the difference is that infinite iterator arguments are typically an error for
+   :func:`map` (because the output is fully evaluated) but represent a common and
+   useful way of supplying arguments to :func:`imap`. Equivalent to::
+
+      def imap(function, *iterables):
+          iterables = map(iter, iterables)
+          while True:
+              args = [next(i) for i in iterables]
+              if function is None:
+                  yield tuple(args)
+              else:
+                  yield function(*args)
+
+
+.. function:: islice(iterable, [start,] stop [, step])
+
+   Make an iterator that returns selected elements from the iterable. If *start* is
+   non-zero, then elements from the iterable are skipped until start is reached.
+   Afterward, elements are returned consecutively unless *step* is set higher than
+   one which results in items being skipped.  If *stop* is ``None``, then iteration
+   continues until the iterator is exhausted, if at all; otherwise, it stops at the
+   specified position.  Unlike regular slicing, :func:`islice` does not support
+   negative values for *start*, *stop*, or *step*.  Can be used to extract related
+   fields from data where the internal structure has been flattened (for example, a
+   multi-line report may list a name field on every third line).  Equivalent to::
+
+      def islice(iterable, *args):
+          s = slice(*args)
+          it = iter(range(s.start or 0, s.stop or sys.maxint, s.step or 1))
+          nexti = next(it)
+          for i, element in enumerate(iterable):
+              if i == nexti:
+                  yield element
+                  nexti = next(it)
+
+   If *start* is ``None``, then iteration starts at zero. If *step* is ``None``,
+   then the step defaults to one.
+
+   .. versionchanged:: 2.5
+      accept ``None`` values for default *start* and *step*.
+
+
+.. function:: izip(*iterables)
+
+   Make an iterator that aggregates elements from each of the iterables. Like
+   :func:`zip` except that it returns an iterator instead of a list.  Used for
+   lock-step iteration over several iterables at a time.  Equivalent to::
+
+      def izip(*iterables):
+          iterables = map(iter, iterables)
+          while iterables:
+              result = [next(it) for it in iterables]
+              yield tuple(result)
+
+   .. versionchanged:: 2.4
+      When no iterables are specified, returns a zero length iterator instead of
+      raising a :exc:`TypeError` exception.
+
+   Note, the left-to-right evaluation order of the iterables is guaranteed. This
+   makes possible an idiom for clustering a data series into n-length groups using
+   ``izip(*[iter(s)]*n)``.  For data that doesn't fit n-length groups exactly, the
+   last tuple can be pre-padded with fill values using ``izip(*[chain(s,
+   [None]*(n-1))]*n)``.
+
+   Note, when :func:`izip` is used with unequal length inputs, subsequent
+   iteration over the longer iterables cannot reliably be continued after
+   :func:`izip` terminates.  Potentially, up to one entry will be missing from
+   each of the left-over iterables. This occurs because a value is fetched from
+   each iterator in- turn, but the process ends when one of the iterators
+   terminates.  This leaves the last fetched values in limbo (they cannot be
+   returned in a final, incomplete tuple and they are cannot be pushed back into
+   the iterator for retrieval with ``next(it)``).  In general, :func:`izip`
+   should only be used with unequal length inputs when you don't care about
+   trailing, unmatched values from the longer iterables.
+
+
+.. function:: izip_longest(*iterables[, fillvalue])
+
+   Make an iterator that aggregates elements from each of the iterables. If the
+   iterables are of uneven length, missing values are filled-in with *fillvalue*.
+   Iteration continues until the longest iterable is exhausted.  Equivalent to::
+
+      def izip_longest(*args, **kwds):
+          fillvalue = kwds.get('fillvalue')
+          def sentinel(counter = ([fillvalue]*(len(args)-1)).pop):
+              yield counter()         # yields the fillvalue, or raises IndexError
+          fillers = repeat(fillvalue)
+          iters = [chain(it, sentinel(), fillers) for it in args]
+          try:
+              for tup in izip(*iters):
+                  yield tup
+          except IndexError:
+              pass
+
+   If one of the iterables is potentially infinite, then the :func:`izip_longest`
+   function should be wrapped with something that limits the number of calls (for
+   example :func:`islice` or :func:`takewhile`).
+
+   .. versionadded:: 2.6
+
+
+.. function:: repeat(object[, times])
+
+   Make an iterator that returns *object* over and over again. Runs indefinitely
+   unless the *times* argument is specified. Used as argument to :func:`imap` for
+   invariant parameters to the called function.  Also used with :func:`izip` to
+   create an invariant part of a tuple record.  Equivalent to::
+
+      def repeat(object, times=None):
+          if times is None:
+              while True:
+                  yield object
+          else:
+              for i in range(times):
+                  yield object
+
+
+.. function:: starmap(function, iterable)
+
+   Make an iterator that computes the function using arguments tuples obtained from
+   the iterable.  Used instead of :func:`imap` when argument parameters are already
+   grouped in tuples from a single iterable (the data has been "pre-zipped").  The
+   difference between :func:`imap` and :func:`starmap` parallels the distinction
+   between ``function(a,b)`` and ``function(*c)``. Equivalent to::
+
+      def starmap(function, iterable):
+          iterable = iter(iterable)
+          while True:
+              yield function(*next(iterable))
+
+
+.. function:: takewhile(predicate, iterable)
+
+   Make an iterator that returns elements from the iterable as long as the
+   predicate is true.  Equivalent to::
+
+      def takewhile(predicate, iterable):
+          for x in iterable:
+              if predicate(x):
+                  yield x
+              else:
+                  break
+
+
+.. function:: tee(iterable[, n=2])
+
+   Return *n* independent iterators from a single iterable. The case where ``n==2``
+   is equivalent to::
+
+      def tee(iterable):
+          def gen(next, data={}, cnt=[0]):
+              for i in count():
+                  if i == cnt[0]:
+                      item = data[i] = next()
+                      cnt[0] += 1
+                  else:
+                      item = data.pop(i)
+                  yield item
+          it = iter(iterable)
+          return (gen(it.__next__), gen(it.__next__))
+
+   Note, once :func:`tee` has made a split, the original *iterable* should not be
+   used anywhere else; otherwise, the *iterable* could get advanced without the tee
+   objects being informed.
+
+   Note, this member of the toolkit may require significant auxiliary storage
+   (depending on how much temporary data needs to be stored). In general, if one
+   iterator is going to use most or all of the data before the other iterator, it
+   is faster to use :func:`list` instead of :func:`tee`.
+
+   .. versionadded:: 2.4
+
+
+.. _itertools-example:
+
+Examples
+--------
+
+The following examples show common uses for each tool and demonstrate ways they
+can be combined. ::
+
+   >>> amounts = [120.15, 764.05, 823.14]
+   >>> for checknum, amount in izip(count(1200), amounts):
+   ...     print 'Check %d is for $%.2f' % (checknum, amount)
+   ...
+   Check 1200 is for $120.15
+   Check 1201 is for $764.05
+   Check 1202 is for $823.14
+
+   >>> import operator
+   >>> for cube in imap(operator.pow, range(1,5), repeat(3)):
+   ...    print cube
+   ...
+   1
+   8
+   27
+   64
+
+   >>> reportlines = ['EuroPython', 'Roster', '', 'alex', '', 'laura',
+   ...                '', 'martin', '', 'walter', '', 'mark']
+   >>> for name in islice(reportlines, 3, None, 2):
+   ...    print name.title()
+   ...
+   Alex
+   Laura
+   Martin
+   Walter
+   Mark
+
+   # Show a dictionary sorted and grouped by value
+   >>> from operator import itemgetter
+   >>> d = dict(a=1, b=2, c=1, d=2, e=1, f=2, g=3)
+   >>> di = sorted(d.iteritems(), key=itemgetter(1))
+   >>> for k, g in groupby(di, key=itemgetter(1)):
+   ...     print k, map(itemgetter(0), g)
+   ...
+   1 ['a', 'c', 'e']
+   2 ['b', 'd', 'f']
+   3 ['g']
+
+   # Find runs of consecutive numbers using groupby.  The key to the solution
+   # is differencing with a range so that consecutive numbers all appear in
+   # same group.
+   >>> data = [ 1,  4,5,6, 10, 15,16,17,18, 22, 25,26,27,28]
+   >>> for k, g in groupby(enumerate(data), lambda t:t[0]-t[1]):
+   ...     print map(operator.itemgetter(1), g)
+   ... 
+   [1]
+   [4, 5, 6]
+   [10]
+   [15, 16, 17, 18]
+   [22]
+   [25, 26, 27, 28]
+
+
+
+.. _itertools-recipes:
+
+Recipes
+-------
+
+This section shows recipes for creating an extended toolset using the existing
+itertools as building blocks.
+
+The extended tools offer the same high performance as the underlying toolset.
+The superior memory performance is kept by processing elements one at a time
+rather than bringing the whole iterable into memory all at once. Code volume is
+kept small by linking the tools together in a functional style which helps
+eliminate temporary variables.  High speed is retained by preferring
+"vectorized" building blocks over the use of for-loops and generators which
+incur interpreter overhead. ::
+
+   def take(n, seq):
+       return list(islice(seq, n))
+
+   def enumerate(iterable):
+       return izip(count(), iterable)
+
+   def tabulate(function):
+       "Return function(0), function(1), ..."
+       return imap(function, count())
+
+   def iteritems(mapping):
+       return izip(mapping.iterkeys(), mapping.itervalues())
+
+   def nth(iterable, n):
+       "Returns the nth item or raise StopIteration"
+       return islice(iterable, n, None).next()
+
+   def all(seq, pred=None):
+       "Returns True if pred(x) is true for every element in the iterable"
+       for elem in ifilterfalse(pred, seq):
+           return False
+       return True
+
+   def any(seq, pred=None):
+       "Returns True if pred(x) is true for at least one element in the iterable"
+       for elem in ifilter(pred, seq):
+           return True
+       return False
+
+   def no(seq, pred=None):
+       "Returns True if pred(x) is false for every element in the iterable"
+       for elem in ifilter(pred, seq):
+           return False
+       return True
+
+   def quantify(seq, pred=None):
+       "Count how many times the predicate is true in the sequence"
+       return sum(imap(pred, seq))
+
+   def padnone(seq):
+       """Returns the sequence elements and then returns None indefinitely.
+
+       Useful for emulating the behavior of the built-in map() function.
+       """
+       return chain(seq, repeat(None))
+
+   def ncycles(seq, n):
+       "Returns the sequence elements n times"
+       return chain(*repeat(seq, n))
+
+   def dotproduct(vec1, vec2):
+       return sum(imap(operator.mul, vec1, vec2))
+
+   def flatten(listOfLists):
+       return list(chain(*listOfLists))
+
+   def repeatfunc(func, times=None, *args):
+       """Repeat calls to func with specified arguments.
+
+       Example:  repeatfunc(random.random)
+       """
+       if times is None:
+           return starmap(func, repeat(args))
+       else:
+           return starmap(func, repeat(args, times))
+
+   def pairwise(iterable):
+       "s -> (s0,s1), (s1,s2), (s2, s3), ..."
+       a, b = tee(iterable)
+       next(b, None)
+       return izip(a, b)
+
+   def grouper(n, iterable, padvalue=None):
+       "grouper(3, 'abcdefg', 'x') --> ('a','b','c'), ('d','e','f'), ('g','x','x')"
+       return izip(*[chain(iterable, repeat(padvalue, n-1))]*n)
+
+
+
diff --git a/Doc/library/keyword.rst b/Doc/library/keyword.rst
new file mode 100644
index 0000000..32a2d34
--- /dev/null
+++ b/Doc/library/keyword.rst
@@ -0,0 +1,22 @@
+
+:mod:`keyword` --- Testing for Python keywords
+==============================================
+
+.. module:: keyword
+   :synopsis: Test whether a string is a keyword in Python.
+
+
+This module allows a Python program to determine if a string is a keyword.
+
+
+.. function:: iskeyword(s)
+
+   Return true if *s* is a Python keyword.
+
+
+.. data:: kwlist
+
+   Sequence containing all the keywords defined for the interpreter.  If any
+   keywords are defined to only be active when particular :mod:`__future__`
+   statements are in effect, these will be included as well.
+
diff --git a/Doc/library/language.rst b/Doc/library/language.rst
new file mode 100644
index 0000000..7d6af7d
--- /dev/null
+++ b/Doc/library/language.rst
@@ -0,0 +1,29 @@
+
+.. _language:
+
+************************
+Python Language Services
+************************
+
+Python provides a number of modules to assist in working with the Python
+language.  These modules support tokenizing, parsing, syntax analysis, bytecode
+disassembly, and various other facilities.
+
+These modules include:
+
+
+.. toctree::
+
+   parser.rst
+   _ast.rst
+   symbol.rst
+   token.rst
+   keyword.rst
+   tokenize.rst
+   tabnanny.rst
+   pyclbr.rst
+   py_compile.rst
+   compileall.rst
+   dis.rst
+   pickletools.rst
+   distutils.rst
diff --git a/Doc/library/linecache.rst b/Doc/library/linecache.rst
new file mode 100644
index 0000000..f3d8379
--- /dev/null
+++ b/Doc/library/linecache.rst
@@ -0,0 +1,52 @@
+
+:mod:`linecache` --- Random access to text lines
+================================================
+
+.. module:: linecache
+   :synopsis: This module provides random access to individual lines from text files.
+.. sectionauthor:: Moshe Zadka 
+
+
+The :mod:`linecache` module allows one to get any line from any file, while
+attempting to optimize internally, using a cache, the common case where many
+lines are read from a single file.  This is used by the :mod:`traceback` module
+to retrieve source lines for inclusion in  the formatted traceback.
+
+The :mod:`linecache` module defines the following functions:
+
+
+.. function:: getline(filename, lineno[, module_globals])
+
+   Get line *lineno* from file named *filename*. This function will never throw an
+   exception --- it will return ``''`` on errors (the terminating newline character
+   will be included for lines that are found).
+
+   .. index:: triple: module; search; path
+
+   If a file named *filename* is not found, the function will look for it in the
+   module search path, ``sys.path``, after first checking for a :pep:`302`
+   ``__loader__`` in *module_globals*, in case the module was imported from a
+   zipfile or other non-filesystem import source.
+
+   .. versionadded:: 2.5
+      The *module_globals* parameter was added.
+
+
+.. function:: clearcache()
+
+   Clear the cache.  Use this function if you no longer need lines from files
+   previously read using :func:`getline`.
+
+
+.. function:: checkcache([filename])
+
+   Check the cache for validity.  Use this function if files in the cache  may have
+   changed on disk, and you require the updated version.  If *filename* is omitted,
+   it will check all the entries in the cache.
+
+Example::
+
+   >>> import linecache
+   >>> linecache.getline('/etc/passwd', 4)
+   'sys:x:3:3:sys:/dev:/bin/sh\n'
+
diff --git a/Doc/library/locale.rst b/Doc/library/locale.rst
new file mode 100644
index 0000000..6d427b7
--- /dev/null
+++ b/Doc/library/locale.rst
@@ -0,0 +1,578 @@
+
+:mod:`locale` --- Internationalization services
+===============================================
+
+.. module:: locale
+   :synopsis: Internationalization services.
+.. moduleauthor:: Martin von Löwis 
+.. sectionauthor:: Martin von Löwis 
+
+
+The :mod:`locale` module opens access to the POSIX locale database and
+functionality. The POSIX locale mechanism allows programmers to deal with
+certain cultural issues in an application, without requiring the programmer to
+know all the specifics of each country where the software is executed.
+
+.. index:: module: _locale
+
+The :mod:`locale` module is implemented on top of the :mod:`_locale` module,
+which in turn uses an ANSI C locale implementation if available.
+
+The :mod:`locale` module defines the following exception and functions:
+
+
+.. exception:: Error
+
+   Exception raised when :func:`setlocale` fails.
+
+
+.. function:: setlocale(category[, locale])
+
+   If *locale* is specified, it may be a string, a tuple of the form ``(language
+   code, encoding)``, or ``None``. If it is a tuple, it is converted to a string
+   using the locale aliasing engine.  If *locale* is given and not ``None``,
+   :func:`setlocale` modifies the locale setting for the *category*.  The available
+   categories are listed in the data description below.  The value is the name of a
+   locale.  An empty string specifies the user's default settings. If the
+   modification of the locale fails, the exception :exc:`Error` is raised.  If
+   successful, the new locale setting is returned.
+
+   If *locale* is omitted or ``None``, the current setting for *category* is
+   returned.
+
+   :func:`setlocale` is not thread safe on most systems. Applications typically
+   start with a call of ::
+
+      import locale
+      locale.setlocale(locale.LC_ALL, '')
+
+   This sets the locale for all categories to the user's default setting (typically
+   specified in the :envvar:`LANG` environment variable).  If the locale is not
+   changed thereafter, using multithreading should not cause problems.
+
+   .. versionchanged:: 2.0
+      Added support for tuple values of the *locale* parameter.
+
+
+.. function:: localeconv()
+
+   Returns the database of the local conventions as a dictionary. This dictionary
+   has the following strings as keys:
+
+   +----------------------+-------------------------------------+--------------------------------+
+   | Category             | Key                                 | Meaning                        |
+   +======================+=====================================+================================+
+   | :const:`LC_NUMERIC`  | ``'decimal_point'``                 | Decimal point character.       |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'grouping'``                      | Sequence of numbers specifying |
+   |                      |                                     | which relative positions the   |
+   |                      |                                     | ``'thousands_sep'`` is         |
+   |                      |                                     | expected.  If the sequence is  |
+   |                      |                                     | terminated with                |
+   |                      |                                     | :const:`CHAR_MAX`, no further  |
+   |                      |                                     | grouping is performed. If the  |
+   |                      |                                     | sequence terminates with a     |
+   |                      |                                     | ``0``,  the last group size is |
+   |                      |                                     | repeatedly used.               |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'thousands_sep'``                 | Character used between groups. |
+   +----------------------+-------------------------------------+--------------------------------+
+   | :const:`LC_MONETARY` | ``'int_curr_symbol'``               | International currency symbol. |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'currency_symbol'``               | Local currency symbol.         |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'p_cs_precedes/n_cs_precedes'``   | Whether the currency symbol    |
+   |                      |                                     | precedes the value (for        |
+   |                      |                                     | positive resp. negative        |
+   |                      |                                     | values).                       |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'p_sep_by_space/n_sep_by_space'`` | Whether the currency symbol is |
+   |                      |                                     | separated from the value  by a |
+   |                      |                                     | space (for positive resp.      |
+   |                      |                                     | negative values).              |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'mon_decimal_point'``             | Decimal point used for         |
+   |                      |                                     | monetary values.               |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'frac_digits'``                   | Number of fractional digits    |
+   |                      |                                     | used in local formatting of    |
+   |                      |                                     | monetary values.               |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'int_frac_digits'``               | Number of fractional digits    |
+   |                      |                                     | used in international          |
+   |                      |                                     | formatting of monetary values. |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'mon_thousands_sep'``             | Group separator used for       |
+   |                      |                                     | monetary values.               |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'mon_grouping'``                  | Equivalent to ``'grouping'``,  |
+   |                      |                                     | used for monetary values.      |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'positive_sign'``                 | Symbol used to annotate a      |
+   |                      |                                     | positive monetary value.       |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'negative_sign'``                 | Symbol used to annotate a      |
+   |                      |                                     | negative monetary value.       |
+   +----------------------+-------------------------------------+--------------------------------+
+   |                      | ``'p_sign_posn/n_sign_posn'``       | The position of the sign (for  |
+   |                      |                                     | positive resp. negative        |
+   |                      |                                     | values), see below.            |
+   +----------------------+-------------------------------------+--------------------------------+
+
+   All numeric values can be set to :const:`CHAR_MAX` to indicate that there is no
+   value specified in this locale.
+
+   The possible values for ``'p_sign_posn'`` and ``'n_sign_posn'`` are given below.
+
+   +--------------+-----------------------------------------+
+   | Value        | Explanation                             |
+   +==============+=========================================+
+   | ``0``        | Currency and value are surrounded by    |
+   |              | parentheses.                            |
+   +--------------+-----------------------------------------+
+   | ``1``        | The sign should precede the value and   |
+   |              | currency symbol.                        |
+   +--------------+-----------------------------------------+
+   | ``2``        | The sign should follow the value and    |
+   |              | currency symbol.                        |
+   +--------------+-----------------------------------------+
+   | ``3``        | The sign should immediately precede the |
+   |              | value.                                  |
+   +--------------+-----------------------------------------+
+   | ``4``        | The sign should immediately follow the  |
+   |              | value.                                  |
+   +--------------+-----------------------------------------+
+   | ``CHAR_MAX`` | Nothing is specified in this locale.    |
+   +--------------+-----------------------------------------+
+
+
+.. function:: nl_langinfo(option)
+
+   Return some locale-specific information as a string. This function is not
+   available on all systems, and the set of possible options might also vary across
+   platforms. The possible argument values are numbers, for which symbolic
+   constants are available in the locale module.
+
+
+.. function:: getdefaultlocale([envvars])
+
+   Tries to determine the default locale settings and returns them as a tuple of
+   the form ``(language code, encoding)``.
+
+   According to POSIX, a program which has not called ``setlocale(LC_ALL, '')``
+   runs using the portable ``'C'`` locale.  Calling ``setlocale(LC_ALL, '')`` lets
+   it use the default locale as defined by the :envvar:`LANG` variable.  Since we
+   do not want to interfere with the current locale setting we thus emulate the
+   behavior in the way described above.
+
+   To maintain compatibility with other platforms, not only the :envvar:`LANG`
+   variable is tested, but a list of variables given as envvars parameter.  The
+   first found to be defined will be used.  *envvars* defaults to the search path
+   used in GNU gettext; it must always contain the variable name ``LANG``.  The GNU
+   gettext search path contains ``'LANGUAGE'``, ``'LC_ALL'``, ``'LC_CTYPE'``, and
+   ``'LANG'``, in that order.
+
+   Except for the code ``'C'``, the language code corresponds to :rfc:`1766`.
+   *language code* and *encoding* may be ``None`` if their values cannot be
+   determined.
+
+   .. versionadded:: 2.0
+
+
+.. function:: getlocale([category])
+
+   Returns the current setting for the given locale category as sequence containing
+   *language code*, *encoding*. *category* may be one of the :const:`LC_\*` values
+   except :const:`LC_ALL`.  It defaults to :const:`LC_CTYPE`.
+
+   Except for the code ``'C'``, the language code corresponds to :rfc:`1766`.
+   *language code* and *encoding* may be ``None`` if their values cannot be
+   determined.
+
+   .. versionadded:: 2.0
+
+
+.. function:: getpreferredencoding([do_setlocale])
+
+   Return the encoding used for text data, according to user preferences.  User
+   preferences are expressed differently on different systems, and might not be
+   available programmatically on some systems, so this function only returns a
+   guess.
+
+   On some systems, it is necessary to invoke :func:`setlocale` to obtain the user
+   preferences, so this function is not thread-safe. If invoking setlocale is not
+   necessary or desired, *do_setlocale* should be set to ``False``.
+
+   .. versionadded:: 2.3
+
+
+.. function:: normalize(localename)
+
+   Returns a normalized locale code for the given locale name.  The returned locale
+   code is formatted for use with :func:`setlocale`.  If normalization fails, the
+   original name is returned unchanged.
+
+   If the given encoding is not known, the function defaults to the default
+   encoding for the locale code just like :func:`setlocale`.
+
+   .. versionadded:: 2.0
+
+
+.. function:: resetlocale([category])
+
+   Sets the locale for *category* to the default setting.
+
+   The default setting is determined by calling :func:`getdefaultlocale`.
+   *category* defaults to :const:`LC_ALL`.
+
+   .. versionadded:: 2.0
+
+
+.. function:: strcoll(string1, string2)
+
+   Compares two strings according to the current :const:`LC_COLLATE` setting. As
+   any other compare function, returns a negative, or a positive value, or ``0``,
+   depending on whether *string1* collates before or after *string2* or is equal to
+   it.
+
+
+.. function:: strxfrm(string)
+
+   .. index:: builtin: cmp
+
+   Transforms a string to one that can be used for the built-in function
+   :func:`cmp`, and still returns locale-aware results.  This function can be used
+   when the same string is compared repeatedly, e.g. when collating a sequence of
+   strings.
+
+
+.. function:: format(format, val[, grouping[, monetary]])
+
+   Formats a number *val* according to the current :const:`LC_NUMERIC` setting.
+   The format follows the conventions of the ``%`` operator.  For floating point
+   values, the decimal point is modified if appropriate.  If *grouping* is true,
+   also takes the grouping into account.
+
+   If *monetary* is true, the conversion uses monetary thousands separator and
+   grouping strings.
+
+   Please note that this function will only work for exactly one %char specifier.
+   For whole format strings, use :func:`format_string`.
+
+   .. versionchanged:: 2.5
+      Added the *monetary* parameter.
+
+
+.. function:: format_string(format, val[, grouping])
+
+   Processes formatting specifiers as in ``format % val``, but takes the current
+   locale settings into account.
+
+   .. versionadded:: 2.5
+
+
+.. function:: currency(val[, symbol[, grouping[, international]]])
+
+   Formats a number *val* according to the current :const:`LC_MONETARY` settings.
+
+   The returned string includes the currency symbol if *symbol* is true, which is
+   the default. If *grouping* is true (which is not the default), grouping is done
+   with the value. If *international* is true (which is not the default), the
+   international currency symbol is used.
+
+   Note that this function will not work with the 'C' locale, so you have to set a
+   locale via :func:`setlocale` first.
+
+   .. versionadded:: 2.5
+
+
+.. function:: str(float)
+
+   Formats a floating point number using the same format as the built-in function
+   ``str(float)``, but takes the decimal point into account.
+
+
+.. function:: atof(string)
+
+   Converts a string to a floating point number, following the :const:`LC_NUMERIC`
+   settings.
+
+
+.. function:: atoi(string)
+
+   Converts a string to an integer, following the :const:`LC_NUMERIC` conventions.
+
+
+.. data:: LC_CTYPE
+
+   .. index:: module: string
+
+   Locale category for the character type functions.  Depending on the settings of
+   this category, the functions of module :mod:`string` dealing with case change
+   their behaviour.
+
+
+.. data:: LC_COLLATE
+
+   Locale category for sorting strings.  The functions :func:`strcoll` and
+   :func:`strxfrm` of the :mod:`locale` module are affected.
+
+
+.. data:: LC_TIME
+
+   Locale category for the formatting of time.  The function :func:`time.strftime`
+   follows these conventions.
+
+
+.. data:: LC_MONETARY
+
+   Locale category for formatting of monetary values.  The available options are
+   available from the :func:`localeconv` function.
+
+
+.. data:: LC_MESSAGES
+
+   Locale category for message display. Python currently does not support
+   application specific locale-aware messages.  Messages displayed by the operating
+   system, like those returned by :func:`os.strerror` might be affected by this
+   category.
+
+
+.. data:: LC_NUMERIC
+
+   Locale category for formatting numbers.  The functions :func:`format`,
+   :func:`atoi`, :func:`atof` and :func:`str` of the :mod:`locale` module are
+   affected by that category.  All other numeric formatting operations are not
+   affected.
+
+
+.. data:: LC_ALL
+
+   Combination of all locale settings.  If this flag is used when the locale is
+   changed, setting the locale for all categories is attempted. If that fails for
+   any category, no category is changed at all.  When the locale is retrieved using
+   this flag, a string indicating the setting for all categories is returned. This
+   string can be later used to restore the settings.
+
+
+.. data:: CHAR_MAX
+
+   This is a symbolic constant used for different values returned by
+   :func:`localeconv`.
+
+The :func:`nl_langinfo` function accepts one of the following keys. Most
+descriptions are taken from the corresponding description in the GNU C library.
+
+
+.. data:: CODESET
+
+   Return a string with the name of the character encoding used in the selected
+   locale.
+
+
+.. data:: D_T_FMT
+
+   Return a string that can be used as a format string for strftime(3) to represent
+   time and date in a locale-specific way.
+
+
+.. data:: D_FMT
+
+   Return a string that can be used as a format string for strftime(3) to represent
+   a date in a locale-specific way.
+
+
+.. data:: T_FMT
+
+   Return a string that can be used as a format string for strftime(3) to represent
+   a time in a locale-specific way.
+
+
+.. data:: T_FMT_AMPM
+
+   The return value can be used as a format string for 'strftime' to represent time
+   in the am/pm format.
+
+
+.. data:: DAY_1 ... DAY_7
+
+   Return name of the n-th day of the week.
+
+   .. warning::
+
+      This follows the US convention of :const:`DAY_1` being Sunday, not the
+      international convention (ISO 8601) that Monday is the first day of the week.
+
+
+.. data:: ABDAY_1 ... ABDAY_7
+
+   Return abbreviated name of the n-th day of the week.
+
+
+.. data:: MON_1 ... MON_12
+
+   Return name of the n-th month.
+
+
+.. data:: ABMON_1 ... ABMON_12
+
+   Return abbreviated name of the n-th month.
+
+
+.. data:: RADIXCHAR
+
+   Return radix character (decimal dot, decimal comma, etc.)
+
+
+.. data:: THOUSEP
+
+   Return separator character for thousands (groups of three digits).
+
+
+.. data:: YESEXPR
+
+   Return a regular expression that can be used with the regex function to
+   recognize a positive response to a yes/no question.
+
+   .. warning::
+
+      The expression is in the syntax suitable for the :cfunc:`regex` function from
+      the C library, which might differ from the syntax used in :mod:`re`.
+
+
+.. data:: NOEXPR
+
+   Return a regular expression that can be used with the regex(3) function to
+   recognize a negative response to a yes/no question.
+
+
+.. data:: CRNCYSTR
+
+   Return the currency symbol, preceded by "-" if the symbol should appear before
+   the value, "+" if the symbol should appear after the value, or "." if the symbol
+   should replace the radix character.
+
+
+.. data:: ERA
+
+   The return value represents the era used in the current locale.
+
+   Most locales do not define this value.  An example of a locale which does define
+   this value is the Japanese one.  In Japan, the traditional representation of
+   dates includes the name of the era corresponding to the then-emperor's reign.
+
+   Normally it should not be necessary to use this value directly. Specifying the
+   ``E`` modifier in their format strings causes the :func:`strftime` function to
+   use this information.  The format of the returned string is not specified, and
+   therefore you should not assume knowledge of it on different systems.
+
+
+.. data:: ERA_YEAR
+
+   The return value gives the year in the relevant era of the locale.
+
+
+.. data:: ERA_D_T_FMT
+
+   This return value can be used as a format string for :func:`strftime` to
+   represent dates and times in a locale-specific era-based way.
+
+
+.. data:: ERA_D_FMT
+
+   This return value can be used as a format string for :func:`strftime` to
+   represent time in a locale-specific era-based way.
+
+
+.. data:: ALT_DIGITS
+
+   The return value is a representation of up to 100 values used to represent the
+   values 0 to 99.
+
+Example::
+
+   >>> import locale
+   >>> loc = locale.getlocale(locale.LC_ALL) # get current locale
+   >>> locale.setlocale(locale.LC_ALL, 'de_DE') # use German locale; name might vary with platform
+   >>> locale.strcoll('f\xe4n', 'foo') # compare a string containing an umlaut 
+   >>> locale.setlocale(locale.LC_ALL, '') # use user's preferred locale
+   >>> locale.setlocale(locale.LC_ALL, 'C') # use default (C) locale
+   >>> locale.setlocale(locale.LC_ALL, loc) # restore saved locale
+
+
+Background, details, hints, tips and caveats
+--------------------------------------------
+
+The C standard defines the locale as a program-wide property that may be
+relatively expensive to change.  On top of that, some implementation are broken
+in such a way that frequent locale changes may cause core dumps.  This makes the
+locale somewhat painful to use correctly.
+
+Initially, when a program is started, the locale is the ``C`` locale, no matter
+what the user's preferred locale is.  The program must explicitly say that it
+wants the user's preferred locale settings by calling ``setlocale(LC_ALL, '')``.
+
+It is generally a bad idea to call :func:`setlocale` in some library routine,
+since as a side effect it affects the entire program.  Saving and restoring it
+is almost as bad: it is expensive and affects other threads that happen to run
+before the settings have been restored.
+
+If, when coding a module for general use, you need a locale independent version
+of an operation that is affected by the locale (such as :func:`string.lower`, or
+certain formats used with :func:`time.strftime`), you will have to find a way to
+do it without using the standard library routine.  Even better is convincing
+yourself that using locale settings is okay.  Only as a last resort should you
+document that your module is not compatible with non-\ ``C`` locale settings.
+
+.. index:: module: string
+
+The case conversion functions in the :mod:`string` module are affected by the
+locale settings.  When a call to the :func:`setlocale` function changes the
+:const:`LC_CTYPE` settings, the variables ``string.lowercase``,
+``string.uppercase`` and ``string.letters`` are recalculated.  Note that code
+that uses these variable through ':keyword:`from` ... :keyword:`import` ...',
+e.g. ``from string import letters``, is not affected by subsequent
+:func:`setlocale` calls.
+
+The only way to perform numeric operations according to the locale is to use the
+special functions defined by this module: :func:`atof`, :func:`atoi`,
+:func:`format`, :func:`str`.
+
+
+.. _embedding-locale:
+
+For extension writers and programs that embed Python
+----------------------------------------------------
+
+Extension modules should never call :func:`setlocale`, except to find out what
+the current locale is.  But since the return value can only be used portably to
+restore it, that is not very useful (except perhaps to find out whether or not
+the locale is ``C``).
+
+When Python code uses the :mod:`locale` module to change the locale, this also
+affects the embedding application.  If the embedding application doesn't want
+this to happen, it should remove the :mod:`_locale` extension module (which does
+all the work) from the table of built-in modules in the :file:`config.c` file,
+and make sure that the :mod:`_locale` module is not accessible as a shared
+library.
+
+
+.. _locale-gettext:
+
+Access to message catalogs
+--------------------------
+
+The locale module exposes the C library's gettext interface on systems that
+provide this interface.  It consists of the functions :func:`gettext`,
+:func:`dgettext`, :func:`dcgettext`, :func:`textdomain`, :func:`bindtextdomain`,
+and :func:`bind_textdomain_codeset`.  These are similar to the same functions in
+the :mod:`gettext` module, but use the C library's binary format for message
+catalogs, and the C library's search algorithms for locating message catalogs.
+
+Python applications should normally find no need to invoke these functions, and
+should use :mod:`gettext` instead.  A known exception to this rule are
+applications that link use additional C libraries which internally invoke
+:cfunc:`gettext` or :func:`dcgettext`.  For these applications, it may be
+necessary to bind the text domain, so that the libraries can properly locate
+their message catalogs.
+
diff --git a/Doc/library/logging.rst b/Doc/library/logging.rst
new file mode 100644
index 0000000..218fb0d
--- /dev/null
+++ b/Doc/library/logging.rst
@@ -0,0 +1,1857 @@
+:mod:`logging` --- Logging facility for Python
+==============================================
+
+.. module:: logging
+   :synopsis: Flexible error logging system for applications.
+
+
+.. moduleauthor:: Vinay Sajip 
+.. sectionauthor:: Vinay Sajip 
+
+
+.. % These apply to all modules, and may be given more than once:
+
+
+
+.. index:: pair: Errors; logging
+
+.. versionadded:: 2.3
+
+This module defines functions and classes which implement a flexible error
+logging system for applications.
+
+Logging is performed by calling methods on instances of the :class:`Logger`
+class (hereafter called :dfn:`loggers`). Each instance has a name, and they are
+conceptually arranged in a name space hierarchy using dots (periods) as
+separators. For example, a logger named "scan" is the parent of loggers
+"scan.text", "scan.html" and "scan.pdf". Logger names can be anything you want,
+and indicate the area of an application in which a logged message originates.
+
+Logged messages also have levels of importance associated with them. The default
+levels provided are :const:`DEBUG`, :const:`INFO`, :const:`WARNING`,
+:const:`ERROR` and :const:`CRITICAL`. As a convenience, you indicate the
+importance of a logged message by calling an appropriate method of
+:class:`Logger`. The methods are :meth:`debug`, :meth:`info`, :meth:`warning`,
+:meth:`error` and :meth:`critical`, which mirror the default levels. You are not
+constrained to use these levels: you can specify your own and use a more general
+:class:`Logger` method, :meth:`log`, which takes an explicit level argument.
+
+The numeric values of logging levels are given in the following table. These are
+primarily of interest if you want to define your own levels, and need them to
+have specific values relative to the predefined levels. If you define a level
+with the same numeric value, it overwrites the predefined value; the predefined
+name is lost.
+
++--------------+---------------+
+| Level        | Numeric value |
++==============+===============+
+| ``CRITICAL`` | 50            |
++--------------+---------------+
+| ``ERROR``    | 40            |
++--------------+---------------+
+| ``WARNING``  | 30            |
++--------------+---------------+
+| ``INFO``     | 20            |
++--------------+---------------+
+| ``DEBUG``    | 10            |
++--------------+---------------+
+| ``NOTSET``   | 0             |
++--------------+---------------+
+
+Levels can also be associated with loggers, being set either by the developer or
+through loading a saved logging configuration. When a logging method is called
+on a logger, the logger compares its own level with the level associated with
+the method call. If the logger's level is higher than the method call's, no
+logging message is actually generated. This is the basic mechanism controlling
+the verbosity of logging output.
+
+Logging messages are encoded as instances of the :class:`LogRecord` class. When
+a logger decides to actually log an event, a :class:`LogRecord` instance is
+created from the logging message.
+
+Logging messages are subjected to a dispatch mechanism through the use of
+:dfn:`handlers`, which are instances of subclasses of the :class:`Handler`
+class. Handlers are responsible for ensuring that a logged message (in the form
+of a :class:`LogRecord`) ends up in a particular location (or set of locations)
+which is useful for the target audience for that message (such as end users,
+support desk staff, system administrators, developers). Handlers are passed
+:class:`LogRecord` instances intended for particular destinations. Each logger
+can have zero, one or more handlers associated with it (via the
+:meth:`addHandler` method of :class:`Logger`). In addition to any handlers
+directly associated with a logger, *all handlers associated with all ancestors
+of the logger* are called to dispatch the message.
+
+Just as for loggers, handlers can have levels associated with them. A handler's
+level acts as a filter in the same way as a logger's level does. If a handler
+decides to actually dispatch an event, the :meth:`emit` method is used to send
+the message to its destination. Most user-defined subclasses of :class:`Handler`
+will need to override this :meth:`emit`.
+
+In addition to the base :class:`Handler` class, many useful subclasses are
+provided:
+
+#. :class:`StreamHandler` instances send error messages to streams (file-like
+   objects).
+
+#. :class:`FileHandler` instances send error messages to disk files.
+
+#. :class:`BaseRotatingHandler` is the base class for handlers that rotate log
+   files at a certain point. It is not meant to be  instantiated directly. Instead,
+   use :class:`RotatingFileHandler` or :class:`TimedRotatingFileHandler`.
+
+#. :class:`RotatingFileHandler` instances send error messages to disk files,
+   with support for maximum log file sizes and log file rotation.
+
+#. :class:`TimedRotatingFileHandler` instances send error messages to disk files
+   rotating the log file at certain timed intervals.
+
+#. :class:`SocketHandler` instances send error messages to TCP/IP sockets.
+
+#. :class:`DatagramHandler` instances send error messages to UDP sockets.
+
+#. :class:`SMTPHandler` instances send error messages to a designated email
+   address.
+
+#. :class:`SysLogHandler` instances send error messages to a Unix syslog daemon,
+   possibly on a remote machine.
+
+#. :class:`NTEventLogHandler` instances send error messages to a Windows
+   NT/2000/XP event log.
+
+#. :class:`MemoryHandler` instances send error messages to a buffer in memory,
+   which is flushed whenever specific criteria are met.
+
+#. :class:`HTTPHandler` instances send error messages to an HTTP server using
+   either ``GET`` or ``POST`` semantics.
+
+The :class:`StreamHandler` and :class:`FileHandler` classes are defined in the
+core logging package. The other handlers are defined in a sub- module,
+:mod:`logging.handlers`. (There is also another sub-module,
+:mod:`logging.config`, for configuration functionality.)
+
+Logged messages are formatted for presentation through instances of the
+:class:`Formatter` class. They are initialized with a format string suitable for
+use with the % operator and a dictionary.
+
+For formatting multiple messages in a batch, instances of
+:class:`BufferingFormatter` can be used. In addition to the format string (which
+is applied to each message in the batch), there is provision for header and
+trailer format strings.
+
+When filtering based on logger level and/or handler level is not enough,
+instances of :class:`Filter` can be added to both :class:`Logger` and
+:class:`Handler` instances (through their :meth:`addFilter` method). Before
+deciding to process a message further, both loggers and handlers consult all
+their filters for permission. If any filter returns a false value, the message
+is not processed further.
+
+The basic :class:`Filter` functionality allows filtering by specific logger
+name. If this feature is used, messages sent to the named logger and its
+children are allowed through the filter, and all others dropped.
+
+In addition to the classes described above, there are a number of module- level
+functions.
+
+
+.. function:: getLogger([name])
+
+   Return a logger with the specified name or, if no name is specified, return a
+   logger which is the root logger of the hierarchy. If specified, the name is
+   typically a dot-separated hierarchical name like *"a"*, *"a.b"* or *"a.b.c.d"*.
+   Choice of these names is entirely up to the developer who is using logging.
+
+   All calls to this function with a given name return the same logger instance.
+   This means that logger instances never need to be passed between different parts
+   of an application.
+
+
+.. function:: getLoggerClass()
+
+   Return either the standard :class:`Logger` class, or the last class passed to
+   :func:`setLoggerClass`. This function may be called from within a new class
+   definition, to ensure that installing a customised :class:`Logger` class will
+   not undo customisations already applied by other code. For example::
+
+      class MyLogger(logging.getLoggerClass()):
+          # ... override behaviour here
+
+
+.. function:: debug(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`DEBUG` on the root logger. The *msg* is the
+   message format string, and the *args* are the arguments which are merged into
+   *msg* using the string formatting operator. (Note that this means that you can
+   use keywords in the format string, together with a single dictionary argument.)
+
+   There are two keyword arguments in *kwargs* which are inspected: *exc_info*
+   which, if it does not evaluate as false, causes exception information to be
+   added to the logging message. If an exception tuple (in the format returned by
+   :func:`sys.exc_info`) is provided, it is used; otherwise, :func:`sys.exc_info`
+   is called to get the exception information.
+
+   The other optional keyword argument is *extra* which can be used to pass a
+   dictionary which is used to populate the __dict__ of the LogRecord created for
+   the logging event with user-defined attributes. These custom attributes can then
+   be used as you like. For example, they could be incorporated into logged
+   messages. For example::
+
+      FORMAT = "%(asctime)-15s %(clientip)s %(user)-8s %(message)s"
+      logging.basicConfig(format=FORMAT)
+      d = {'clientip': '192.168.0.1', 'user': 'fbloggs'}
+      logging.warning("Protocol problem: %s", "connection reset", extra=d)
+
+   would print something like  ::
+
+      2006-02-08 22:20:02,165 192.168.0.1 fbloggs  Protocol problem: connection reset
+
+   The keys in the dictionary passed in *extra* should not clash with the keys used
+   by the logging system. (See the :class:`Formatter` documentation for more
+   information on which keys are used by the logging system.)
+
+   If you choose to use these attributes in logged messages, you need to exercise
+   some care. In the above example, for instance, the :class:`Formatter` has been
+   set up with a format string which expects 'clientip' and 'user' in the attribute
+   dictionary of the LogRecord. If these are missing, the message will not be
+   logged because a string formatting exception will occur. So in this case, you
+   always need to pass the *extra* dictionary with these keys.
+
+   While this might be annoying, this feature is intended for use in specialized
+   circumstances, such as multi-threaded servers where the same code executes in
+   many contexts, and interesting conditions which arise are dependent on this
+   context (such as remote client IP address and authenticated user name, in the
+   above example). In such circumstances, it is likely that specialized
+   :class:`Formatter`\ s would be used with particular :class:`Handler`\ s.
+
+   .. versionchanged:: 2.5
+      *extra* was added.
+
+
+.. function:: info(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`INFO` on the root logger. The arguments are
+   interpreted as for :func:`debug`.
+
+
+.. function:: warning(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`WARNING` on the root logger. The arguments are
+   interpreted as for :func:`debug`.
+
+
+.. function:: error(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`ERROR` on the root logger. The arguments are
+   interpreted as for :func:`debug`.
+
+
+.. function:: critical(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`CRITICAL` on the root logger. The arguments
+   are interpreted as for :func:`debug`.
+
+
+.. function:: exception(msg[, *args])
+
+   Logs a message with level :const:`ERROR` on the root logger. The arguments are
+   interpreted as for :func:`debug`. Exception info is added to the logging
+   message. This function should only be called from an exception handler.
+
+
+.. function:: log(level, msg[, *args[, **kwargs]])
+
+   Logs a message with level *level* on the root logger. The other arguments are
+   interpreted as for :func:`debug`.
+
+
+.. function:: disable(lvl)
+
+   Provides an overriding level *lvl* for all loggers which takes precedence over
+   the logger's own level. When the need arises to temporarily throttle logging
+   output down across the whole application, this function can be useful.
+
+
+.. function:: addLevelName(lvl, levelName)
+
+   Associates level *lvl* with text *levelName* in an internal dictionary, which is
+   used to map numeric levels to a textual representation, for example when a
+   :class:`Formatter` formats a message. This function can also be used to define
+   your own levels. The only constraints are that all levels used must be
+   registered using this function, levels should be positive integers and they
+   should increase in increasing order of severity.
+
+
+.. function:: getLevelName(lvl)
+
+   Returns the textual representation of logging level *lvl*. If the level is one
+   of the predefined levels :const:`CRITICAL`, :const:`ERROR`, :const:`WARNING`,
+   :const:`INFO` or :const:`DEBUG` then you get the corresponding string. If you
+   have associated levels with names using :func:`addLevelName` then the name you
+   have associated with *lvl* is returned. If a numeric value corresponding to one
+   of the defined levels is passed in, the corresponding string representation is
+   returned. Otherwise, the string "Level %s" % lvl is returned.
+
+
+.. function:: makeLogRecord(attrdict)
+
+   Creates and returns a new :class:`LogRecord` instance whose attributes are
+   defined by *attrdict*. This function is useful for taking a pickled
+   :class:`LogRecord` attribute dictionary, sent over a socket, and reconstituting
+   it as a :class:`LogRecord` instance at the receiving end.
+
+
+.. function:: basicConfig([**kwargs])
+
+   Does basic configuration for the logging system by creating a
+   :class:`StreamHandler` with a default :class:`Formatter` and adding it to the
+   root logger. The functions :func:`debug`, :func:`info`, :func:`warning`,
+   :func:`error` and :func:`critical` will call :func:`basicConfig` automatically
+   if no handlers are defined for the root logger.
+
+   .. versionchanged:: 2.4
+      Formerly, :func:`basicConfig` did not take any keyword arguments.
+
+   The following keyword arguments are supported.
+
+   +--------------+---------------------------------------------+
+   | Format       | Description                                 |
+   +==============+=============================================+
+   | ``filename`` | Specifies that a FileHandler be created,    |
+   |              | using the specified filename, rather than a |
+   |              | StreamHandler.                              |
+   +--------------+---------------------------------------------+
+   | ``filemode`` | Specifies the mode to open the file, if     |
+   |              | filename is specified (if filemode is       |
+   |              | unspecified, it defaults to 'a').           |
+   +--------------+---------------------------------------------+
+   | ``format``   | Use the specified format string for the     |
+   |              | handler.                                    |
+   +--------------+---------------------------------------------+
+   | ``datefmt``  | Use the specified date/time format.         |
+   +--------------+---------------------------------------------+
+   | ``level``    | Set the root logger level to the specified  |
+   |              | level.                                      |
+   +--------------+---------------------------------------------+
+   | ``stream``   | Use the specified stream to initialize the  |
+   |              | StreamHandler. Note that this argument is   |
+   |              | incompatible with 'filename' - if both are  |
+   |              | present, 'stream' is ignored.               |
+   +--------------+---------------------------------------------+
+
+
+.. function:: shutdown()
+
+   Informs the logging system to perform an orderly shutdown by flushing and
+   closing all handlers.
+
+
+.. function:: setLoggerClass(klass)
+
+   Tells the logging system to use the class *klass* when instantiating a logger.
+   The class should define :meth:`__init__` such that only a name argument is
+   required, and the :meth:`__init__` should call :meth:`Logger.__init__`. This
+   function is typically called before any loggers are instantiated by applications
+   which need to use custom logger behavior.
+
+
+.. seealso::
+
+   :pep:`282` - A Logging System
+      The proposal which described this feature for inclusion in the Python standard
+      library.
+
+   `Original Python :mod:`logging` package `_
+      This is the original source for the :mod:`logging` package.  The version of the
+      package available from this site is suitable for use with Python 1.5.2, 2.1.x
+      and 2.2.x, which do not include the :mod:`logging` package in the standard
+      library.
+
+
+Logger Objects
+--------------
+
+Loggers have the following attributes and methods. Note that Loggers are never
+instantiated directly, but always through the module-level function
+``logging.getLogger(name)``.
+
+
+.. attribute:: Logger.propagate
+
+   If this evaluates to false, logging messages are not passed by this logger or by
+   child loggers to higher level (ancestor) loggers. The constructor sets this
+   attribute to 1.
+
+
+.. method:: Logger.setLevel(lvl)
+
+   Sets the threshold for this logger to *lvl*. Logging messages which are less
+   severe than *lvl* will be ignored. When a logger is created, the level is set to
+   :const:`NOTSET` (which causes all messages to be processed when the logger is
+   the root logger, or delegation to the parent when the logger is a non-root
+   logger). Note that the root logger is created with level :const:`WARNING`.
+
+   The term "delegation to the parent" means that if a logger has a level of
+   NOTSET, its chain of ancestor loggers is traversed until either an ancestor with
+   a level other than NOTSET is found, or the root is reached.
+
+   If an ancestor is found with a level other than NOTSET, then that ancestor's
+   level is treated as the effective level of the logger where the ancestor search
+   began, and is used to determine how a logging event is handled.
+
+   If the root is reached, and it has a level of NOTSET, then all messages will be
+   processed. Otherwise, the root's level will be used as the effective level.
+
+
+.. method:: Logger.isEnabledFor(lvl)
+
+   Indicates if a message of severity *lvl* would be processed by this logger.
+   This method checks first the module-level level set by
+   ``logging.disable(lvl)`` and then the logger's effective level as determined
+   by :meth:`getEffectiveLevel`.
+
+
+.. method:: Logger.getEffectiveLevel()
+
+   Indicates the effective level for this logger. If a value other than
+   :const:`NOTSET` has been set using :meth:`setLevel`, it is returned. Otherwise,
+   the hierarchy is traversed towards the root until a value other than
+   :const:`NOTSET` is found, and that value is returned.
+
+
+.. method:: Logger.debug(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`DEBUG` on this logger. The *msg* is the
+   message format string, and the *args* are the arguments which are merged into
+   *msg* using the string formatting operator. (Note that this means that you can
+   use keywords in the format string, together with a single dictionary argument.)
+
+   There are two keyword arguments in *kwargs* which are inspected: *exc_info*
+   which, if it does not evaluate as false, causes exception information to be
+   added to the logging message. If an exception tuple (in the format returned by
+   :func:`sys.exc_info`) is provided, it is used; otherwise, :func:`sys.exc_info`
+   is called to get the exception information.
+
+   The other optional keyword argument is *extra* which can be used to pass a
+   dictionary which is used to populate the __dict__ of the LogRecord created for
+   the logging event with user-defined attributes. These custom attributes can then
+   be used as you like. For example, they could be incorporated into logged
+   messages. For example::
+
+      FORMAT = "%(asctime)-15s %(clientip)s %(user)-8s %(message)s"
+      logging.basicConfig(format=FORMAT)
+      dict = { 'clientip' : '192.168.0.1', 'user' : 'fbloggs' }
+      logger = logging.getLogger("tcpserver")
+      logger.warning("Protocol problem: %s", "connection reset", extra=d)
+
+   would print something like  ::
+
+      2006-02-08 22:20:02,165 192.168.0.1 fbloggs  Protocol problem: connection reset
+
+   The keys in the dictionary passed in *extra* should not clash with the keys used
+   by the logging system. (See the :class:`Formatter` documentation for more
+   information on which keys are used by the logging system.)
+
+   If you choose to use these attributes in logged messages, you need to exercise
+   some care. In the above example, for instance, the :class:`Formatter` has been
+   set up with a format string which expects 'clientip' and 'user' in the attribute
+   dictionary of the LogRecord. If these are missing, the message will not be
+   logged because a string formatting exception will occur. So in this case, you
+   always need to pass the *extra* dictionary with these keys.
+
+   While this might be annoying, this feature is intended for use in specialized
+   circumstances, such as multi-threaded servers where the same code executes in
+   many contexts, and interesting conditions which arise are dependent on this
+   context (such as remote client IP address and authenticated user name, in the
+   above example). In such circumstances, it is likely that specialized
+   :class:`Formatter`\ s would be used with particular :class:`Handler`\ s.
+
+   .. versionchanged:: 2.5
+      *extra* was added.
+
+
+.. method:: Logger.info(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`INFO` on this logger. The arguments are
+   interpreted as for :meth:`debug`.
+
+
+.. method:: Logger.warning(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`WARNING` on this logger. The arguments are
+   interpreted as for :meth:`debug`.
+
+
+.. method:: Logger.error(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`ERROR` on this logger. The arguments are
+   interpreted as for :meth:`debug`.
+
+
+.. method:: Logger.critical(msg[, *args[, **kwargs]])
+
+   Logs a message with level :const:`CRITICAL` on this logger. The arguments are
+   interpreted as for :meth:`debug`.
+
+
+.. method:: Logger.log(lvl, msg[, *args[, **kwargs]])
+
+   Logs a message with integer level *lvl* on this logger. The other arguments are
+   interpreted as for :meth:`debug`.
+
+
+.. method:: Logger.exception(msg[, *args])
+
+   Logs a message with level :const:`ERROR` on this logger. The arguments are
+   interpreted as for :meth:`debug`. Exception info is added to the logging
+   message. This method should only be called from an exception handler.
+
+
+.. method:: Logger.addFilter(filt)
+
+   Adds the specified filter *filt* to this logger.
+
+
+.. method:: Logger.removeFilter(filt)
+
+   Removes the specified filter *filt* from this logger.
+
+
+.. method:: Logger.filter(record)
+
+   Applies this logger's filters to the record and returns a true value if the
+   record is to be processed.
+
+
+.. method:: Logger.addHandler(hdlr)
+
+   Adds the specified handler *hdlr* to this logger.
+
+
+.. method:: Logger.removeHandler(hdlr)
+
+   Removes the specified handler *hdlr* from this logger.
+
+
+.. method:: Logger.findCaller()
+
+   Finds the caller's source filename and line number. Returns the filename, line
+   number and function name as a 3-element tuple.
+
+   .. versionchanged:: 2.5
+      The function name was added. In earlier versions, the filename and line number
+      were returned as a 2-element tuple..
+
+
+.. method:: Logger.handle(record)
+
+   Handles a record by passing it to all handlers associated with this logger and
+   its ancestors (until a false value of *propagate* is found). This method is used
+   for unpickled records received from a socket, as well as those created locally.
+   Logger-level filtering is applied using :meth:`filter`.
+
+
+.. method:: Logger.makeRecord(name, lvl, fn, lno, msg, args, exc_info [, func, extra])
+
+   This is a factory method which can be overridden in subclasses to create
+   specialized :class:`LogRecord` instances.
+
+   .. versionchanged:: 2.5
+      *func* and *extra* were added.
+
+
+.. _minimal-example:
+
+Basic example
+-------------
+
+.. versionchanged:: 2.4
+   formerly :func:`basicConfig` did not take any keyword arguments.
+
+The :mod:`logging` package provides a lot of flexibility, and its configuration
+can appear daunting.  This section demonstrates that simple use of the logging
+package is possible.
+
+The simplest example shows logging to the console::
+
+   import logging
+
+   logging.debug('A debug message')
+   logging.info('Some information')
+   logging.warning('A shot across the bows')
+
+If you run the above script, you'll see this::
+
+   WARNING:root:A shot across the bows
+
+Because no particular logger was specified, the system used the root logger. The
+debug and info messages didn't appear because by default, the root logger is
+configured to only handle messages with a severity of WARNING or above. The
+message format is also a configuration default, as is the output destination of
+the messages - ``sys.stderr``. The severity level, the message format and
+destination can be easily changed, as shown in the example below::
+
+   import logging
+
+   logging.basicConfig(level=logging.DEBUG,
+                       format='%(asctime)s %(levelname)s %(message)s',
+                       filename='/tmp/myapp.log',
+                       filemode='w')
+   logging.debug('A debug message')
+   logging.info('Some information')
+   logging.warning('A shot across the bows')
+
+The :meth:`basicConfig` method is used to change the configuration defaults,
+which results in output (written to ``/tmp/myapp.log``) which should look
+something like the following::
+
+   2004-07-02 13:00:08,743 DEBUG A debug message
+   2004-07-02 13:00:08,743 INFO Some information
+   2004-07-02 13:00:08,743 WARNING A shot across the bows
+
+This time, all messages with a severity of DEBUG or above were handled, and the
+format of the messages was also changed, and output went to the specified file
+rather than the console.
+
+Formatting uses standard Python string formatting - see section
+:ref:`string-formatting`. The format string takes the following common
+specifiers. For a complete list of specifiers, consult the :class:`Formatter`
+documentation.
+
++-------------------+-----------------------------------------------+
+| Format            | Description                                   |
++===================+===============================================+
+| ``%(name)s``      | Name of the logger (logging channel).         |
++-------------------+-----------------------------------------------+
+| ``%(levelname)s`` | Text logging level for the message            |
+|                   | (``'DEBUG'``, ``'INFO'``, ``'WARNING'``,      |
+|                   | ``'ERROR'``, ``'CRITICAL'``).                 |
++-------------------+-----------------------------------------------+
+| ``%(asctime)s``   | Human-readable time when the                  |
+|                   | :class:`LogRecord` was created.  By default   |
+|                   | this is of the form "2003-07-08 16:49:45,896" |
+|                   | (the numbers after the comma are millisecond  |
+|                   | portion of the time).                         |
++-------------------+-----------------------------------------------+
+| ``%(message)s``   | The logged message.                           |
++-------------------+-----------------------------------------------+
+
+To change the date/time format, you can pass an additional keyword parameter,
+*datefmt*, as in the following::
+
+   import logging
+
+   logging.basicConfig(level=logging.DEBUG,
+                       format='%(asctime)s %(levelname)-8s %(message)s',
+                       datefmt='%a, %d %b %Y %H:%M:%S',
+                       filename='/temp/myapp.log',
+                       filemode='w')
+   logging.debug('A debug message')
+   logging.info('Some information')
+   logging.warning('A shot across the bows')
+
+which would result in output like ::
+
+   Fri, 02 Jul 2004 13:06:18 DEBUG    A debug message
+   Fri, 02 Jul 2004 13:06:18 INFO     Some information
+   Fri, 02 Jul 2004 13:06:18 WARNING  A shot across the bows
+
+The date format string follows the requirements of :func:`strftime` - see the
+documentation for the :mod:`time` module.
+
+If, instead of sending logging output to the console or a file, you'd rather use
+a file-like object which you have created separately, you can pass it to
+:func:`basicConfig` using the *stream* keyword argument. Note that if both
+*stream* and *filename* keyword arguments are passed, the *stream* argument is
+ignored.
+
+Of course, you can put variable information in your output. To do this, simply
+have the message be a format string and pass in additional arguments containing
+the variable information, as in the following example::
+
+   import logging
+
+   logging.basicConfig(level=logging.DEBUG,
+                       format='%(asctime)s %(levelname)-8s %(message)s',
+                       datefmt='%a, %d %b %Y %H:%M:%S',
+                       filename='/temp/myapp.log',
+                       filemode='w')
+   logging.error('Pack my box with %d dozen %s', 5, 'liquor jugs')
+
+which would result in ::
+
+   Wed, 21 Jul 2004 15:35:16 ERROR    Pack my box with 5 dozen liquor jugs
+
+
+.. _multiple-destinations:
+
+Logging to multiple destinations
+--------------------------------
+
+Let's say you want to log to console and file with different message formats and
+in differing circumstances. Say you want to log messages with levels of DEBUG
+and higher to file, and those messages at level INFO and higher to the console.
+Let's also assume that the file should contain timestamps, but the console
+messages should not. Here's how you can achieve this::
+
+   import logging
+
+   # set up logging to file - see previous section for more details
+   logging.basicConfig(level=logging.DEBUG,
+                       format='%(asctime)s %(name)-12s %(levelname)-8s %(message)s',
+                       datefmt='%m-%d %H:%M',
+                       filename='/temp/myapp.log',
+                       filemode='w')
+   # define a Handler which writes INFO messages or higher to the sys.stderr
+   console = logging.StreamHandler()
+   console.setLevel(logging.INFO)
+   # set a format which is simpler for console use
+   formatter = logging.Formatter('%(name)-12s: %(levelname)-8s %(message)s')
+   # tell the handler to use this format
+   console.setFormatter(formatter)
+   # add the handler to the root logger
+   logging.getLogger('').addHandler(console)
+
+   # Now, we can log to the root logger, or any other logger. First the root...
+   logging.info('Jackdaws love my big sphinx of quartz.')
+
+   # Now, define a couple of other loggers which might represent areas in your
+   # application:
+
+   logger1 = logging.getLogger('myapp.area1')
+   logger2 = logging.getLogger('myapp.area2')
+
+   logger1.debug('Quick zephyrs blow, vexing daft Jim.')
+   logger1.info('How quickly daft jumping zebras vex.')
+   logger2.warning('Jail zesty vixen who grabbed pay from quack.')
+   logger2.error('The five boxing wizards jump quickly.')
+
+When you run this, on the console you will see ::
+
+   root        : INFO     Jackdaws love my big sphinx of quartz.
+   myapp.area1 : INFO     How quickly daft jumping zebras vex.
+   myapp.area2 : WARNING  Jail zesty vixen who grabbed pay from quack.
+   myapp.area2 : ERROR    The five boxing wizards jump quickly.
+
+and in the file you will see something like ::
+
+   10-22 22:19 root         INFO     Jackdaws love my big sphinx of quartz.
+   10-22 22:19 myapp.area1  DEBUG    Quick zephyrs blow, vexing daft Jim.
+   10-22 22:19 myapp.area1  INFO     How quickly daft jumping zebras vex.
+   10-22 22:19 myapp.area2  WARNING  Jail zesty vixen who grabbed pay from quack.
+   10-22 22:19 myapp.area2  ERROR    The five boxing wizards jump quickly.
+
+As you can see, the DEBUG message only shows up in the file. The other messages
+are sent to both destinations.
+
+This example uses console and file handlers, but you can use any number and
+combination of handlers you choose.
+
+
+.. _network-logging:
+
+Sending and receiving logging events across a network
+-----------------------------------------------------
+
+Let's say you want to send logging events across a network, and handle them at
+the receiving end. A simple way of doing this is attaching a
+:class:`SocketHandler` instance to the root logger at the sending end::
+
+   import logging, logging.handlers
+
+   rootLogger = logging.getLogger('')
+   rootLogger.setLevel(logging.DEBUG)
+   socketHandler = logging.handlers.SocketHandler('localhost',
+                       logging.handlers.DEFAULT_TCP_LOGGING_PORT)
+   # don't bother with a formatter, since a socket handler sends the event as
+   # an unformatted pickle
+   rootLogger.addHandler(socketHandler)
+
+   # Now, we can log to the root logger, or any other logger. First the root...
+   logging.info('Jackdaws love my big sphinx of quartz.')
+
+   # Now, define a couple of other loggers which might represent areas in your
+   # application:
+
+   logger1 = logging.getLogger('myapp.area1')
+   logger2 = logging.getLogger('myapp.area2')
+
+   logger1.debug('Quick zephyrs blow, vexing daft Jim.')
+   logger1.info('How quickly daft jumping zebras vex.')
+   logger2.warning('Jail zesty vixen who grabbed pay from quack.')
+   logger2.error('The five boxing wizards jump quickly.')
+
+At the receiving end, you can set up a receiver using the :mod:`SocketServer`
+module. Here is a basic working example::
+
+   import cPickle
+   import logging
+   import logging.handlers
+   import SocketServer
+   import struct
+
+
+   class LogRecordStreamHandler(SocketServer.StreamRequestHandler):
+       """Handler for a streaming logging request.
+
+       This basically logs the record using whatever logging policy is
+       configured locally.
+       """
+
+       def handle(self):
+           """
+           Handle multiple requests - each expected to be a 4-byte length,
+           followed by the LogRecord in pickle format. Logs the record
+           according to whatever policy is configured locally.
+           """
+           while 1:
+               chunk = self.connection.recv(4)
+               if len(chunk) < 4:
+                   break
+               slen = struct.unpack(">L", chunk)[0]
+               chunk = self.connection.recv(slen)
+               while len(chunk) < slen:
+                   chunk = chunk + self.connection.recv(slen - len(chunk))
+               obj = self.unPickle(chunk)
+               record = logging.makeLogRecord(obj)
+               self.handleLogRecord(record)
+
+       def unPickle(self, data):
+           return cPickle.loads(data)
+
+       def handleLogRecord(self, record):
+           # if a name is specified, we use the named logger rather than the one
+           # implied by the record.
+           if self.server.logname is not None:
+               name = self.server.logname
+           else:
+               name = record.name
+           logger = logging.getLogger(name)
+           # N.B. EVERY record gets logged. This is because Logger.handle
+           # is normally called AFTER logger-level filtering. If you want
+           # to do filtering, do it at the client end to save wasting
+           # cycles and network bandwidth!
+           logger.handle(record)
+
+   class LogRecordSocketReceiver(SocketServer.ThreadingTCPServer):
+       """simple TCP socket-based logging receiver suitable for testing.
+       """
+
+       allow_reuse_address = 1
+
+       def __init__(self, host='localhost',
+                    port=logging.handlers.DEFAULT_TCP_LOGGING_PORT,
+                    handler=LogRecordStreamHandler):
+           SocketServer.ThreadingTCPServer.__init__(self, (host, port), handler)
+           self.abort = 0
+           self.timeout = 1
+           self.logname = None
+
+       def serve_until_stopped(self):
+           import select
+           abort = 0
+           while not abort:
+               rd, wr, ex = select.select([self.socket.fileno()],
+                                          [], [],
+                                          self.timeout)
+               if rd:
+                   self.handle_request()
+               abort = self.abort
+
+   def main():
+       logging.basicConfig(
+           format="%(relativeCreated)5d %(name)-15s %(levelname)-8s %(message)s")
+       tcpserver = LogRecordSocketReceiver()
+       print "About to start TCP server..."
+       tcpserver.serve_until_stopped()
+
+   if __name__ == "__main__":
+       main()
+
+First run the server, and then the client. On the client side, nothing is
+printed on the console; on the server side, you should see something like::
+
+   About to start TCP server...
+      59 root            INFO     Jackdaws love my big sphinx of quartz.
+      59 myapp.area1     DEBUG    Quick zephyrs blow, vexing daft Jim.
+      69 myapp.area1     INFO     How quickly daft jumping zebras vex.
+      69 myapp.area2     WARNING  Jail zesty vixen who grabbed pay from quack.
+      69 myapp.area2     ERROR    The five boxing wizards jump quickly.
+
+
+Handler Objects
+---------------
+
+Handlers have the following attributes and methods. Note that :class:`Handler`
+is never instantiated directly; this class acts as a base for more useful
+subclasses. However, the :meth:`__init__` method in subclasses needs to call
+:meth:`Handler.__init__`.
+
+
+.. method:: Handler.__init__(level=NOTSET)
+
+   Initializes the :class:`Handler` instance by setting its level, setting the list
+   of filters to the empty list and creating a lock (using :meth:`createLock`) for
+   serializing access to an I/O mechanism.
+
+
+.. method:: Handler.createLock()
+
+   Initializes a thread lock which can be used to serialize access to underlying
+   I/O functionality which may not be threadsafe.
+
+
+.. method:: Handler.acquire()
+
+   Acquires the thread lock created with :meth:`createLock`.
+
+
+.. method:: Handler.release()
+
+   Releases the thread lock acquired with :meth:`acquire`.
+
+
+.. method:: Handler.setLevel(lvl)
+
+   Sets the threshold for this handler to *lvl*. Logging messages which are less
+   severe than *lvl* will be ignored. When a handler is created, the level is set
+   to :const:`NOTSET` (which causes all messages to be processed).
+
+
+.. method:: Handler.setFormatter(form)
+
+   Sets the :class:`Formatter` for this handler to *form*.
+
+
+.. method:: Handler.addFilter(filt)
+
+   Adds the specified filter *filt* to this handler.
+
+
+.. method:: Handler.removeFilter(filt)
+
+   Removes the specified filter *filt* from this handler.
+
+
+.. method:: Handler.filter(record)
+
+   Applies this handler's filters to the record and returns a true value if the
+   record is to be processed.
+
+
+.. method:: Handler.flush()
+
+   Ensure all logging output has been flushed. This version does nothing and is
+   intended to be implemented by subclasses.
+
+
+.. method:: Handler.close()
+
+   Tidy up any resources used by the handler. This version does nothing and is
+   intended to be implemented by subclasses.
+
+
+.. method:: Handler.handle(record)
+
+   Conditionally emits the specified logging record, depending on filters which may
+   have been added to the handler. Wraps the actual emission of the record with
+   acquisition/release of the I/O thread lock.
+
+
+.. method:: Handler.handleError(record)
+
+   This method should be called from handlers when an exception is encountered
+   during an :meth:`emit` call. By default it does nothing, which means that
+   exceptions get silently ignored. This is what is mostly wanted for a logging
+   system - most users will not care about errors in the logging system, they are
+   more interested in application errors. You could, however, replace this with a
+   custom handler if you wish. The specified record is the one which was being
+   processed when the exception occurred.
+
+
+.. method:: Handler.format(record)
+
+   Do formatting for a record - if a formatter is set, use it. Otherwise, use the
+   default formatter for the module.
+
+
+.. method:: Handler.emit(record)
+
+   Do whatever it takes to actually log the specified logging record. This version
+   is intended to be implemented by subclasses and so raises a
+   :exc:`NotImplementedError`.
+
+
+StreamHandler
+^^^^^^^^^^^^^
+
+The :class:`StreamHandler` class, located in the core :mod:`logging` package,
+sends logging output to streams such as *sys.stdout*, *sys.stderr* or any
+file-like object (or, more precisely, any object which supports :meth:`write`
+and :meth:`flush` methods).
+
+
+.. class:: StreamHandler([strm])
+
+   Returns a new instance of the :class:`StreamHandler` class. If *strm* is
+   specified, the instance will use it for logging output; otherwise, *sys.stderr*
+   will be used.
+
+
+.. method:: StreamHandler.emit(record)
+
+   If a formatter is specified, it is used to format the record. The record is then
+   written to the stream with a trailing newline. If exception information is
+   present, it is formatted using :func:`traceback.print_exception` and appended to
+   the stream.
+
+
+.. method:: StreamHandler.flush()
+
+   Flushes the stream by calling its :meth:`flush` method. Note that the
+   :meth:`close` method is inherited from :class:`Handler` and so does nothing, so
+   an explicit :meth:`flush` call may be needed at times.
+
+
+FileHandler
+^^^^^^^^^^^
+
+The :class:`FileHandler` class, located in the core :mod:`logging` package,
+sends logging output to a disk file.  It inherits the output functionality from
+:class:`StreamHandler`.
+
+
+.. class:: FileHandler(filename[, mode[, encoding]])
+
+   Returns a new instance of the :class:`FileHandler` class. The specified file is
+   opened and used as the stream for logging. If *mode* is not specified,
+   :const:`'a'` is used.  If *encoding* is not *None*, it is used to open the file
+   with that encoding.  By default, the file grows indefinitely.
+
+
+.. method:: FileHandler.close()
+
+   Closes the file.
+
+
+.. method:: FileHandler.emit(record)
+
+   Outputs the record to the file.
+
+
+WatchedFileHandler
+^^^^^^^^^^^^^^^^^^
+
+.. versionadded:: 2.6
+
+The :class:`WatchedFileHandler` class, located in the :mod:`logging.handlers`
+module, is a :class:`FileHandler` which watches the file it is logging to. If
+the file changes, it is closed and reopened using the file name.
+
+A file change can happen because of usage of programs such as *newsyslog* and
+*logrotate* which perform log file rotation. This handler, intended for use
+under Unix/Linux, watches the file to see if it has changed since the last emit.
+(A file is deemed to have changed if its device or inode have changed.) If the
+file has changed, the old file stream is closed, and the file opened to get a
+new stream.
+
+This handler is not appropriate for use under Windows, because under Windows
+open log files cannot be moved or renamed - logging opens the files with
+exclusive locks - and so there is no need for such a handler. Furthermore,
+*ST_INO* is not supported under Windows; :func:`stat` always returns zero for
+this value.
+
+
+.. class:: WatchedFileHandler(filename[,mode[, encoding]])
+
+   Returns a new instance of the :class:`WatchedFileHandler` class. The specified
+   file is opened and used as the stream for logging. If *mode* is not specified,
+   :const:`'a'` is used.  If *encoding* is not *None*, it is used to open the file
+   with that encoding.  By default, the file grows indefinitely.
+
+
+.. method:: WatchedFileHandler.emit(record)
+
+   Outputs the record to the file, but first checks to see if the file has changed.
+   If it has, the existing stream is flushed and closed and the file opened again,
+   before outputting the record to the file.
+
+
+RotatingFileHandler
+^^^^^^^^^^^^^^^^^^^
+
+The :class:`RotatingFileHandler` class, located in the :mod:`logging.handlers`
+module, supports rotation of disk log files.
+
+
+.. class:: RotatingFileHandler(filename[, mode[, maxBytes[, backupCount]]])
+
+   Returns a new instance of the :class:`RotatingFileHandler` class. The specified
+   file is opened and used as the stream for logging. If *mode* is not specified,
+   ``'a'`` is used. By default, the file grows indefinitely.
+
+   You can use the *maxBytes* and *backupCount* values to allow the file to
+   :dfn:`rollover` at a predetermined size. When the size is about to be exceeded,
+   the file is closed and a new file is silently opened for output. Rollover occurs
+   whenever the current log file is nearly *maxBytes* in length; if *maxBytes* is
+   zero, rollover never occurs.  If *backupCount* is non-zero, the system will save
+   old log files by appending the extensions ".1", ".2" etc., to the filename. For
+   example, with a *backupCount* of 5 and a base file name of :file:`app.log`, you
+   would get :file:`app.log`, :file:`app.log.1`, :file:`app.log.2`, up to
+   :file:`app.log.5`. The file being written to is always :file:`app.log`.  When
+   this file is filled, it is closed and renamed to :file:`app.log.1`, and if files
+   :file:`app.log.1`, :file:`app.log.2`, etc.  exist, then they are renamed to
+   :file:`app.log.2`, :file:`app.log.3` etc.  respectively.
+
+
+.. method:: RotatingFileHandler.doRollover()
+
+   Does a rollover, as described above.
+
+
+.. method:: RotatingFileHandler.emit(record)
+
+   Outputs the record to the file, catering for rollover as described previously.
+
+
+TimedRotatingFileHandler
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+The :class:`TimedRotatingFileHandler` class, located in the
+:mod:`logging.handlers` module, supports rotation of disk log files at certain
+timed intervals.
+
+
+.. class:: TimedRotatingFileHandler(filename [,when [,interval [,backupCount]]])
+
+   Returns a new instance of the :class:`TimedRotatingFileHandler` class. The
+   specified file is opened and used as the stream for logging. On rotating it also
+   sets the filename suffix. Rotating happens based on the product of *when* and
+   *interval*.
+
+   You can use the *when* to specify the type of *interval*. The list of possible
+   values is, note that they are not case sensitive:
+
+   +----------+-----------------------+
+   | Value    | Type of interval      |
+   +==========+=======================+
+   | S        | Seconds               |
+   +----------+-----------------------+
+   | M        | Minutes               |
+   +----------+-----------------------+
+   | H        | Hours                 |
+   +----------+-----------------------+
+   | D        | Days                  |
+   +----------+-----------------------+
+   | W        | Week day (0=Monday)   |
+   +----------+-----------------------+
+   | midnight | Roll over at midnight |
+   +----------+-----------------------+
+
+   If *backupCount* is non-zero, the system will save old log files by appending
+   extensions to the filename. The extensions are date-and-time based, using the
+   strftime format ``%Y-%m-%d_%H-%M-%S`` or a leading portion thereof, depending on
+   the rollover interval. At most *backupCount* files will be kept, and if more
+   would be created when rollover occurs, the oldest one is deleted.
+
+
+.. method:: TimedRotatingFileHandler.doRollover()
+
+   Does a rollover, as described above.
+
+
+.. method:: TimedRotatingFileHandler.emit(record)
+
+   Outputs the record to the file, catering for rollover as described above.
+
+
+SocketHandler
+^^^^^^^^^^^^^
+
+The :class:`SocketHandler` class, located in the :mod:`logging.handlers` module,
+sends logging output to a network socket. The base class uses a TCP socket.
+
+
+.. class:: SocketHandler(host, port)
+
+   Returns a new instance of the :class:`SocketHandler` class intended to
+   communicate with a remote machine whose address is given by *host* and *port*.
+
+
+.. method:: SocketHandler.close()
+
+   Closes the socket.
+
+
+.. method:: SocketHandler.emit()
+
+   Pickles the record's attribute dictionary and writes it to the socket in binary
+   format. If there is an error with the socket, silently drops the packet. If the
+   connection was previously lost, re-establishes the connection. To unpickle the
+   record at the receiving end into a :class:`LogRecord`, use the
+   :func:`makeLogRecord` function.
+
+
+.. method:: SocketHandler.handleError()
+
+   Handles an error which has occurred during :meth:`emit`. The most likely cause
+   is a lost connection. Closes the socket so that we can retry on the next event.
+
+
+.. method:: SocketHandler.makeSocket()
+
+   This is a factory method which allows subclasses to define the precise type of
+   socket they want. The default implementation creates a TCP socket
+   (:const:`socket.SOCK_STREAM`).
+
+
+.. method:: SocketHandler.makePickle(record)
+
+   Pickles the record's attribute dictionary in binary format with a length prefix,
+   and returns it ready for transmission across the socket.
+
+
+.. method:: SocketHandler.send(packet)
+
+   Send a pickled string *packet* to the socket. This function allows for partial
+   sends which can happen when the network is busy.
+
+
+DatagramHandler
+^^^^^^^^^^^^^^^
+
+The :class:`DatagramHandler` class, located in the :mod:`logging.handlers`
+module, inherits from :class:`SocketHandler` to support sending logging messages
+over UDP sockets.
+
+
+.. class:: DatagramHandler(host, port)
+
+   Returns a new instance of the :class:`DatagramHandler` class intended to
+   communicate with a remote machine whose address is given by *host* and *port*.
+
+
+.. method:: DatagramHandler.emit()
+
+   Pickles the record's attribute dictionary and writes it to the socket in binary
+   format. If there is an error with the socket, silently drops the packet. To
+   unpickle the record at the receiving end into a :class:`LogRecord`, use the
+   :func:`makeLogRecord` function.
+
+
+.. method:: DatagramHandler.makeSocket()
+
+   The factory method of :class:`SocketHandler` is here overridden to create a UDP
+   socket (:const:`socket.SOCK_DGRAM`).
+
+
+.. method:: DatagramHandler.send(s)
+
+   Send a pickled string to a socket.
+
+
+SysLogHandler
+^^^^^^^^^^^^^
+
+The :class:`SysLogHandler` class, located in the :mod:`logging.handlers` module,
+supports sending logging messages to a remote or local Unix syslog.
+
+
+.. class:: SysLogHandler([address[, facility]])
+
+   Returns a new instance of the :class:`SysLogHandler` class intended to
+   communicate with a remote Unix machine whose address is given by *address* in
+   the form of a ``(host, port)`` tuple.  If *address* is not specified,
+   ``('localhost', 514)`` is used.  The address is used to open a UDP socket.  An
+   alternative to providing a ``(host, port)`` tuple is providing an address as a
+   string, for example "/dev/log". In this case, a Unix domain socket is used to
+   send the message to the syslog. If *facility* is not specified,
+   :const:`LOG_USER` is used.
+
+
+.. method:: SysLogHandler.close()
+
+   Closes the socket to the remote host.
+
+
+.. method:: SysLogHandler.emit(record)
+
+   The record is formatted, and then sent to the syslog server. If exception
+   information is present, it is *not* sent to the server.
+
+
+.. method:: SysLogHandler.encodePriority(facility, priority)
+
+   Encodes the facility and priority into an integer. You can pass in strings or
+   integers - if strings are passed, internal mapping dictionaries are used to
+   convert them to integers.
+
+
+NTEventLogHandler
+^^^^^^^^^^^^^^^^^
+
+The :class:`NTEventLogHandler` class, located in the :mod:`logging.handlers`
+module, supports sending logging messages to a local Windows NT, Windows 2000 or
+Windows XP event log. Before you can use it, you need Mark Hammond's Win32
+extensions for Python installed.
+
+
+.. class:: NTEventLogHandler(appname[, dllname[, logtype]])
+
+   Returns a new instance of the :class:`NTEventLogHandler` class. The *appname* is
+   used to define the application name as it appears in the event log. An
+   appropriate registry entry is created using this name. The *dllname* should give
+   the fully qualified pathname of a .dll or .exe which contains message
+   definitions to hold in the log (if not specified, ``'win32service.pyd'`` is used
+   - this is installed with the Win32 extensions and contains some basic
+   placeholder message definitions. Note that use of these placeholders will make
+   your event logs big, as the entire message source is held in the log. If you
+   want slimmer logs, you have to pass in the name of your own .dll or .exe which
+   contains the message definitions you want to use in the event log). The
+   *logtype* is one of ``'Application'``, ``'System'`` or ``'Security'``, and
+   defaults to ``'Application'``.
+
+
+.. method:: NTEventLogHandler.close()
+
+   At this point, you can remove the application name from the registry as a source
+   of event log entries. However, if you do this, you will not be able to see the
+   events as you intended in the Event Log Viewer - it needs to be able to access
+   the registry to get the .dll name. The current version does not do this (in fact
+   it doesn't do anything).
+
+
+.. method:: NTEventLogHandler.emit(record)
+
+   Determines the message ID, event category and event type, and then logs the
+   message in the NT event log.
+
+
+.. method:: NTEventLogHandler.getEventCategory(record)
+
+   Returns the event category for the record. Override this if you want to specify
+   your own categories. This version returns 0.
+
+
+.. method:: NTEventLogHandler.getEventType(record)
+
+   Returns the event type for the record. Override this if you want to specify your
+   own types. This version does a mapping using the handler's typemap attribute,
+   which is set up in :meth:`__init__` to a dictionary which contains mappings for
+   :const:`DEBUG`, :const:`INFO`, :const:`WARNING`, :const:`ERROR` and
+   :const:`CRITICAL`. If you are using your own levels, you will either need to
+   override this method or place a suitable dictionary in the handler's *typemap*
+   attribute.
+
+
+.. method:: NTEventLogHandler.getMessageID(record)
+
+   Returns the message ID for the record. If you are using your own messages, you
+   could do this by having the *msg* passed to the logger being an ID rather than a
+   format string. Then, in here, you could use a dictionary lookup to get the
+   message ID. This version returns 1, which is the base message ID in
+   :file:`win32service.pyd`.
+
+
+SMTPHandler
+^^^^^^^^^^^
+
+The :class:`SMTPHandler` class, located in the :mod:`logging.handlers` module,
+supports sending logging messages to an email address via SMTP.
+
+
+.. class:: SMTPHandler(mailhost, fromaddr, toaddrs, subject[, credentials])
+
+   Returns a new instance of the :class:`SMTPHandler` class. The instance is
+   initialized with the from and to addresses and subject line of the email. The
+   *toaddrs* should be a list of strings. To specify a non-standard SMTP port, use
+   the (host, port) tuple format for the *mailhost* argument. If you use a string,
+   the standard SMTP port is used. If your SMTP server requires authentication, you
+   can specify a (username, password) tuple for the *credentials* argument.
+
+   .. versionchanged:: 2.6
+      *credentials* was added.
+
+
+.. method:: SMTPHandler.emit(record)
+
+   Formats the record and sends it to the specified addressees.
+
+
+.. method:: SMTPHandler.getSubject(record)
+
+   If you want to specify a subject line which is record-dependent, override this
+   method.
+
+
+MemoryHandler
+^^^^^^^^^^^^^
+
+The :class:`MemoryHandler` class, located in the :mod:`logging.handlers` module,
+supports buffering of logging records in memory, periodically flushing them to a
+:dfn:`target` handler. Flushing occurs whenever the buffer is full, or when an
+event of a certain severity or greater is seen.
+
+:class:`MemoryHandler` is a subclass of the more general
+:class:`BufferingHandler`, which is an abstract class. This buffers logging
+records in memory. Whenever each record is added to the buffer, a check is made
+by calling :meth:`shouldFlush` to see if the buffer should be flushed.  If it
+should, then :meth:`flush` is expected to do the needful.
+
+
+.. class:: BufferingHandler(capacity)
+
+   Initializes the handler with a buffer of the specified capacity.
+
+
+.. method:: BufferingHandler.emit(record)
+
+   Appends the record to the buffer. If :meth:`shouldFlush` returns true, calls
+   :meth:`flush` to process the buffer.
+
+
+.. method:: BufferingHandler.flush()
+
+   You can override this to implement custom flushing behavior. This version just
+   zaps the buffer to empty.
+
+
+.. method:: BufferingHandler.shouldFlush(record)
+
+   Returns true if the buffer is up to capacity. This method can be overridden to
+   implement custom flushing strategies.
+
+
+.. class:: MemoryHandler(capacity[, flushLevel [, target]])
+
+   Returns a new instance of the :class:`MemoryHandler` class. The instance is
+   initialized with a buffer size of *capacity*. If *flushLevel* is not specified,
+   :const:`ERROR` is used. If no *target* is specified, the target will need to be
+   set using :meth:`setTarget` before this handler does anything useful.
+
+
+.. method:: MemoryHandler.close()
+
+   Calls :meth:`flush`, sets the target to :const:`None` and clears the buffer.
+
+
+.. method:: MemoryHandler.flush()
+
+   For a :class:`MemoryHandler`, flushing means just sending the buffered records
+   to the target, if there is one. Override if you want different behavior.
+
+
+.. method:: MemoryHandler.setTarget(target)
+
+   Sets the target handler for this handler.
+
+
+.. method:: MemoryHandler.shouldFlush(record)
+
+   Checks for buffer full or a record at the *flushLevel* or higher.
+
+
+HTTPHandler
+^^^^^^^^^^^
+
+The :class:`HTTPHandler` class, located in the :mod:`logging.handlers` module,
+supports sending logging messages to a Web server, using either ``GET`` or
+``POST`` semantics.
+
+
+.. class:: HTTPHandler(host, url[, method])
+
+   Returns a new instance of the :class:`HTTPHandler` class. The instance is
+   initialized with a host address, url and HTTP method. The *host* can be of the
+   form ``host:port``, should you need to use a specific port number. If no
+   *method* is specified, ``GET`` is used.
+
+
+.. method:: HTTPHandler.emit(record)
+
+   Sends the record to the Web server as an URL-encoded dictionary.
+
+
+Formatter Objects
+-----------------
+
+:class:`Formatter`\ s have the following attributes and methods. They are
+responsible for converting a :class:`LogRecord` to (usually) a string which can
+be interpreted by either a human or an external system. The base
+:class:`Formatter` allows a formatting string to be specified. If none is
+supplied, the default value of ``'%(message)s'`` is used.
+
+A Formatter can be initialized with a format string which makes use of knowledge
+of the :class:`LogRecord` attributes - such as the default value mentioned above
+making use of the fact that the user's message and arguments are pre-formatted
+into a :class:`LogRecord`'s *message* attribute.  This format string contains
+standard python %-style mapping keys. See section :ref:`string-formatting`
+for more information on string formatting.
+
+Currently, the useful mapping keys in a :class:`LogRecord` are:
+
++-------------------------+-----------------------------------------------+
+| Format                  | Description                                   |
++=========================+===============================================+
+| ``%(name)s``            | Name of the logger (logging channel).         |
++-------------------------+-----------------------------------------------+
+| ``%(levelno)s``         | Numeric logging level for the message         |
+|                         | (:const:`DEBUG`, :const:`INFO`,               |
+|                         | :const:`WARNING`, :const:`ERROR`,             |
+|                         | :const:`CRITICAL`).                           |
++-------------------------+-----------------------------------------------+
+| ``%(levelname)s``       | Text logging level for the message            |
+|                         | (``'DEBUG'``, ``'INFO'``, ``'WARNING'``,      |
+|                         | ``'ERROR'``, ``'CRITICAL'``).                 |
++-------------------------+-----------------------------------------------+
+| ``%(pathname)s``        | Full pathname of the source file where the    |
+|                         | logging call was issued (if available).       |
++-------------------------+-----------------------------------------------+
+| ``%(filename)s``        | Filename portion of pathname.                 |
++-------------------------+-----------------------------------------------+
+| ``%(module)s``          | Module (name portion of filename).            |
++-------------------------+-----------------------------------------------+
+| ``%(funcName)s``        | Name of function containing the logging call. |
++-------------------------+-----------------------------------------------+
+| ``%(lineno)d``          | Source line number where the logging call was |
+|                         | issued (if available).                        |
++-------------------------+-----------------------------------------------+
+| ``%(created)f``         | Time when the :class:`LogRecord` was created  |
+|                         | (as returned by :func:`time.time`).           |
++-------------------------+-----------------------------------------------+
+| ``%(relativeCreated)d`` | Time in milliseconds when the LogRecord was   |
+|                         | created, relative to the time the logging     |
+|                         | module was loaded.                            |
++-------------------------+-----------------------------------------------+
+| ``%(asctime)s``         | Human-readable time when the                  |
+|                         | :class:`LogRecord` was created.  By default   |
+|                         | this is of the form "2003-07-08 16:49:45,896" |
+|                         | (the numbers after the comma are millisecond  |
+|                         | portion of the time).                         |
++-------------------------+-----------------------------------------------+
+| ``%(msecs)d``           | Millisecond portion of the time when the      |
+|                         | :class:`LogRecord` was created.               |
++-------------------------+-----------------------------------------------+
+| ``%(thread)d``          | Thread ID (if available).                     |
++-------------------------+-----------------------------------------------+
+| ``%(threadName)s``      | Thread name (if available).                   |
++-------------------------+-----------------------------------------------+
+| ``%(process)d``         | Process ID (if available).                    |
++-------------------------+-----------------------------------------------+
+| ``%(message)s``         | The logged message, computed as ``msg %       |
+|                         | args``.                                       |
++-------------------------+-----------------------------------------------+
+
+.. versionchanged:: 2.5
+   *funcName* was added.
+
+
+.. class:: Formatter([fmt[, datefmt]])
+
+   Returns a new instance of the :class:`Formatter` class. The instance is
+   initialized with a format string for the message as a whole, as well as a format
+   string for the date/time portion of a message. If no *fmt* is specified,
+   ``'%(message)s'`` is used. If no *datefmt* is specified, the ISO8601 date format
+   is used.
+
+
+.. method:: Formatter.format(record)
+
+   The record's attribute dictionary is used as the operand to a string formatting
+   operation. Returns the resulting string. Before formatting the dictionary, a
+   couple of preparatory steps are carried out. The *message* attribute of the
+   record is computed using *msg* % *args*. If the formatting string contains
+   ``'(asctime)'``, :meth:`formatTime` is called to format the event time. If there
+   is exception information, it is formatted using :meth:`formatException` and
+   appended to the message.
+
+
+.. method:: Formatter.formatTime(record[, datefmt])
+
+   This method should be called from :meth:`format` by a formatter which wants to
+   make use of a formatted time. This method can be overridden in formatters to
+   provide for any specific requirement, but the basic behavior is as follows: if
+   *datefmt* (a string) is specified, it is used with :func:`time.strftime` to
+   format the creation time of the record. Otherwise, the ISO8601 format is used.
+   The resulting string is returned.
+
+
+.. method:: Formatter.formatException(exc_info)
+
+   Formats the specified exception information (a standard exception tuple as
+   returned by :func:`sys.exc_info`) as a string. This default implementation just
+   uses :func:`traceback.print_exception`. The resulting string is returned.
+
+
+Filter Objects
+--------------
+
+:class:`Filter`\ s can be used by :class:`Handler`\ s and :class:`Logger`\ s for
+more sophisticated filtering than is provided by levels. The base filter class
+only allows events which are below a certain point in the logger hierarchy. For
+example, a filter initialized with "A.B" will allow events logged by loggers
+"A.B", "A.B.C", "A.B.C.D", "A.B.D" etc. but not "A.BB", "B.A.B" etc. If
+initialized with the empty string, all events are passed.
+
+
+.. class:: Filter([name])
+
+   Returns an instance of the :class:`Filter` class. If *name* is specified, it
+   names a logger which, together with its children, will have its events allowed
+   through the filter. If no name is specified, allows every event.
+
+
+.. method:: Filter.filter(record)
+
+   Is the specified record to be logged? Returns zero for no, nonzero for yes. If
+   deemed appropriate, the record may be modified in-place by this method.
+
+
+LogRecord Objects
+-----------------
+
+:class:`LogRecord` instances are created every time something is logged. They
+contain all the information pertinent to the event being logged. The main
+information passed in is in msg and args, which are combined using msg % args to
+create the message field of the record. The record also includes information
+such as when the record was created, the source line where the logging call was
+made, and any exception information to be logged.
+
+
+.. class:: LogRecord(name, lvl, pathname, lineno, msg, args, exc_info [, func])
+
+   Returns an instance of :class:`LogRecord` initialized with interesting
+   information. The *name* is the logger name; *lvl* is the numeric level;
+   *pathname* is the absolute pathname of the source file in which the logging
+   call was made; *lineno* is the line number in that file where the logging
+   call is found; *msg* is the user-supplied message (a format string); *args*
+   is the tuple which, together with *msg*, makes up the user message; and
+   *exc_info* is the exception tuple obtained by calling :func:`sys.exc_info`
+   (or :const:`None`, if no exception information is available). The *func* is
+   the name of the function from which the logging call was made. If not
+   specified, it defaults to ``None``.
+
+   .. versionchanged:: 2.5
+      *func* was added.
+
+
+.. method:: LogRecord.getMessage()
+
+   Returns the message for this :class:`LogRecord` instance after merging any
+   user-supplied arguments with the message.
+
+
+Thread Safety
+-------------
+
+The logging module is intended to be thread-safe without any special work
+needing to be done by its clients. It achieves this though using threading
+locks; there is one lock to serialize access to the module's shared data, and
+each handler also creates a lock to serialize access to its underlying I/O.
+
+
+Configuration
+-------------
+
+
+.. _logging-config-api:
+
+Configuration functions
+^^^^^^^^^^^^^^^^^^^^^^^
+
+.. % 
+
+The following functions configure the logging module. They are located in the
+:mod:`logging.config` module.  Their use is optional --- you can configure the
+logging module using these functions or by making calls to the main API (defined
+in :mod:`logging` itself) and defining handlers which are declared either in
+:mod:`logging` or :mod:`logging.handlers`.
+
+
+.. function:: fileConfig(fname[, defaults])
+
+   Reads the logging configuration from a ConfigParser-format file named *fname*.
+   This function can be called several times from an application, allowing an end
+   user the ability to select from various pre-canned configurations (if the
+   developer provides a mechanism to present the choices and load the chosen
+   configuration). Defaults to be passed to ConfigParser can be specified in the
+   *defaults* argument.
+
+
+.. function:: listen([port])
+
+   Starts up a socket server on the specified port, and listens for new
+   configurations. If no port is specified, the module's default
+   :const:`DEFAULT_LOGGING_CONFIG_PORT` is used. Logging configurations will be
+   sent as a file suitable for processing by :func:`fileConfig`. Returns a
+   :class:`Thread` instance on which you can call :meth:`start` to start the
+   server, and which you can :meth:`join` when appropriate. To stop the server,
+   call :func:`stopListening`. To send a configuration to the socket, read in the
+   configuration file and send it to the socket as a string of bytes preceded by a
+   four-byte length packed in binary using struct.\ ``pack('>L', n)``.
+
+
+.. function:: stopListening()
+
+   Stops the listening server which was created with a call to :func:`listen`. This
+   is typically called before calling :meth:`join` on the return value from
+   :func:`listen`.
+
+
+.. _logging-config-fileformat:
+
+Configuration file format
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. % 
+
+The configuration file format understood by :func:`fileConfig` is based on
+ConfigParser functionality. The file must contain sections called ``[loggers]``,
+``[handlers]`` and ``[formatters]`` which identify by name the entities of each
+type which are defined in the file. For each such entity, there is a separate
+section which identified how that entity is configured. Thus, for a logger named
+``log01`` in the ``[loggers]`` section, the relevant configuration details are
+held in a section ``[logger_log01]``. Similarly, a handler called ``hand01`` in
+the ``[handlers]`` section will have its configuration held in a section called
+``[handler_hand01]``, while a formatter called ``form01`` in the
+``[formatters]`` section will have its configuration specified in a section
+called ``[formatter_form01]``. The root logger configuration must be specified
+in a section called ``[logger_root]``.
+
+Examples of these sections in the file are given below. ::
+
+   [loggers]
+   keys=root,log02,log03,log04,log05,log06,log07
+
+   [handlers]
+   keys=hand01,hand02,hand03,hand04,hand05,hand06,hand07,hand08,hand09
+
+   [formatters]
+   keys=form01,form02,form03,form04,form05,form06,form07,form08,form09
+
+The root logger must specify a level and a list of handlers. An example of a
+root logger section is given below. ::
+
+   [logger_root]
+   level=NOTSET
+   handlers=hand01
+
+The ``level`` entry can be one of ``DEBUG, INFO, WARNING, ERROR, CRITICAL`` or
+``NOTSET``. For the root logger only, ``NOTSET`` means that all messages will be
+logged. Level values are :func:`eval`\ uated in the context of the ``logging``
+package's namespace.
+
+The ``handlers`` entry is a comma-separated list of handler names, which must
+appear in the ``[handlers]`` section. These names must appear in the
+``[handlers]`` section and have corresponding sections in the configuration
+file.
+
+For loggers other than the root logger, some additional information is required.
+This is illustrated by the following example. ::
+
+   [logger_parser]
+   level=DEBUG
+   handlers=hand01
+   propagate=1
+   qualname=compiler.parser
+
+The ``level`` and ``handlers`` entries are interpreted as for the root logger,
+except that if a non-root logger's level is specified as ``NOTSET``, the system
+consults loggers higher up the hierarchy to determine the effective level of the
+logger. The ``propagate`` entry is set to 1 to indicate that messages must
+propagate to handlers higher up the logger hierarchy from this logger, or 0 to
+indicate that messages are **not** propagated to handlers up the hierarchy. The
+``qualname`` entry is the hierarchical channel name of the logger, that is to
+say the name used by the application to get the logger.
+
+Sections which specify handler configuration are exemplified by the following.
+::
+
+   [handler_hand01]
+   class=StreamHandler
+   level=NOTSET
+   formatter=form01
+   args=(sys.stdout,)
+
+The ``class`` entry indicates the handler's class (as determined by :func:`eval`
+in the ``logging`` package's namespace). The ``level`` is interpreted as for
+loggers, and ``NOTSET`` is taken to mean "log everything".
+
+The ``formatter`` entry indicates the key name of the formatter for this
+handler. If blank, a default formatter (``logging._defaultFormatter``) is used.
+If a name is specified, it must appear in the ``[formatters]`` section and have
+a corresponding section in the configuration file.
+
+The ``args`` entry, when :func:`eval`\ uated in the context of the ``logging``
+package's namespace, is the list of arguments to the constructor for the handler
+class. Refer to the constructors for the relevant handlers, or to the examples
+below, to see how typical entries are constructed. ::
+
+   [handler_hand02]
+   class=FileHandler
+   level=DEBUG
+   formatter=form02
+   args=('python.log', 'w')
+
+   [handler_hand03]
+   class=handlers.SocketHandler
+   level=INFO
+   formatter=form03
+   args=('localhost', handlers.DEFAULT_TCP_LOGGING_PORT)
+
+   [handler_hand04]
+   class=handlers.DatagramHandler
+   level=WARN
+   formatter=form04
+   args=('localhost', handlers.DEFAULT_UDP_LOGGING_PORT)
+
+   [handler_hand05]
+   class=handlers.SysLogHandler
+   level=ERROR
+   formatter=form05
+   args=(('localhost', handlers.SYSLOG_UDP_PORT), handlers.SysLogHandler.LOG_USER)
+
+   [handler_hand06]
+   class=handlers.NTEventLogHandler
+   level=CRITICAL
+   formatter=form06
+   args=('Python Application', '', 'Application')
+
+   [handler_hand07]
+   class=handlers.SMTPHandler
+   level=WARN
+   formatter=form07
+   args=('localhost', 'from@abc', ['user1@abc', 'user2@xyz'], 'Logger Subject')
+
+   [handler_hand08]
+   class=handlers.MemoryHandler
+   level=NOTSET
+   formatter=form08
+   target=
+   args=(10, ERROR)
+
+   [handler_hand09]
+   class=handlers.HTTPHandler
+   level=NOTSET
+   formatter=form09
+   args=('localhost:9022', '/log', 'GET')
+
+Sections which specify formatter configuration are typified by the following. ::
+
+   [formatter_form01]
+   format=F1 %(asctime)s %(levelname)s %(message)s
+   datefmt=
+   class=logging.Formatter
+
+The ``format`` entry is the overall format string, and the ``datefmt`` entry is
+the :func:`strftime`\ -compatible date/time format string. If empty, the package
+substitutes ISO8601 format date/times, which is almost equivalent to specifying
+the date format string "The ISO8601 format also specifies milliseconds, which
+are appended to the result of using the above format string, with a comma
+separator. An example time in ISO8601 format is ``2003-01-23 00:29:50,411``.
+
+.. % Y-%m-%d %H:%M:%S".
+
+The ``class`` entry is optional.  It indicates the name of the formatter's class
+(as a dotted module and class name.)  This option is useful for instantiating a
+:class:`Formatter` subclass.  Subclasses of :class:`Formatter` can present
+exception tracebacks in an expanded or condensed format.
+
diff --git a/Doc/library/mac.rst b/Doc/library/mac.rst
new file mode 100644
index 0000000..791eb81
--- /dev/null
+++ b/Doc/library/mac.rst
@@ -0,0 +1,23 @@
+.. _mac-specific-services:
+
+*************************
+MacOS X specific services
+*************************
+
+This chapter describes modules that are only available on the Mac OS X platform.
+
+See the chapters :ref:`mac-scripting` and :ref:`undoc-mac-modules` for more
+modules, and the HOWTO :ref:`using-on-mac` for a general introduction to
+Mac-specific Python programming.
+
+
+.. toctree::
+
+   ic.rst
+   macos.rst
+   macostools.rst
+   easydialogs.rst
+   framework.rst
+   autogil.rst
+   carbon.rst
+   colorpicker.rst
diff --git a/Doc/library/macos.rst b/Doc/library/macos.rst
new file mode 100644
index 0000000..543f868
--- /dev/null
+++ b/Doc/library/macos.rst
@@ -0,0 +1,95 @@
+
+:mod:`MacOS` --- Access to Mac OS interpreter features
+======================================================
+
+.. module:: MacOS
+   :platform: Mac
+   :synopsis: Access to Mac OS-specific interpreter features.
+
+
+This module provides access to MacOS specific functionality in the Python
+interpreter, such as how the interpreter eventloop functions and the like. Use
+with care.
+
+Note the capitalization of the module name; this is a historical artifact.
+
+
+.. data:: runtimemodel
+
+   Always ``'macho'``, from Python 2.4 on. In earlier versions of Python the value
+   could also be ``'ppc'`` for the classic Mac OS 8 runtime model or ``'carbon'``
+   for the Mac OS 9 runtime model.
+
+
+.. data:: linkmodel
+
+   The way the interpreter has been linked. As extension modules may be
+   incompatible between linking models, packages could use this information to give
+   more decent error messages. The value is one of ``'static'`` for a statically
+   linked Python, ``'framework'`` for Python in a Mac OS X framework, ``'shared'``
+   for Python in a standard Unix shared library. Older Pythons could also have the
+   value ``'cfm'`` for Mac OS 9-compatible Python.
+
+
+.. exception:: Error
+
+   .. index:: module: macerrors
+
+   This exception is raised on MacOS generated errors, either from functions in
+   this module or from other mac-specific modules like the toolbox interfaces. The
+   arguments are the integer error code (the :cdata:`OSErr` value) and a textual
+   description of the error code. Symbolic names for all known error codes are
+   defined in the standard module :mod:`macerrors`.
+
+
+.. function:: GetErrorString(errno)
+
+   Return the textual description of MacOS error code *errno*.
+
+
+.. function:: DebugStr(message [, object])
+
+   On Mac OS X the string is simply printed to stderr (on older Mac OS systems more
+   elaborate functionality was available), but it provides a convenient location to
+   attach a breakpoint in a low-level debugger like :program:`gdb`.
+
+
+.. function:: SysBeep()
+
+   Ring the bell.
+
+
+.. function:: GetTicks()
+
+   Get the number of clock ticks (1/60th of a second) since system boot.
+
+
+.. function:: GetCreatorAndType(file)
+
+   Return the file creator and file type as two four-character strings. The *file*
+   parameter can be a pathname or an ``FSSpec`` or  ``FSRef`` object.
+
+
+.. function:: SetCreatorAndType(file, creator, type)
+
+   Set the file creator and file type. The *file* parameter can be a pathname or an
+   ``FSSpec`` or  ``FSRef`` object. *creator* and *type* must be four character
+   strings.
+
+
+.. function:: openrf(name [, mode])
+
+   Open the resource fork of a file. Arguments are the same as for the built-in
+   function :func:`open`. The object returned has file-like semantics, but it is
+   not a Python file object, so there may be subtle differences.
+
+
+.. function:: WMAvailable()
+
+   Checks whether the current process has access to the window manager. The method
+   will return ``False`` if the window manager is not available, for instance when
+   running on Mac OS X Server or when logged in via ssh, or when the current
+   interpreter is not running from a fullblown application bundle. A script runs
+   from an application bundle either when it has been started with
+   :program:`pythonw` instead of :program:`python` or when running  as an applet.
+
diff --git a/Doc/library/macosa.rst b/Doc/library/macosa.rst
new file mode 100644
index 0000000..67475ed
--- /dev/null
+++ b/Doc/library/macosa.rst
@@ -0,0 +1,92 @@
+
+.. _mac-scripting:
+
+*********************
+MacPython OSA Modules
+*********************
+
+This chapter describes the current implementation of the Open Scripting
+Architecure (OSA, also commonly referred to as AppleScript) for Python, allowing
+you to control scriptable applications from your Python program, and with a
+fairly pythonic interface. Development on this set of modules has stopped, and a
+replacement is expected for Python 2.5.
+
+For a description of the various components of AppleScript and OSA, and to get
+an understanding of the architecture and terminology, you should read Apple's
+documentation. The "Applescript Language Guide" explains the conceptual model
+and the terminology, and documents the standard suite. The "Open Scripting
+Architecture" document explains how to use OSA from an application programmers
+point of view. In the Apple Help Viewer these books are located in the Developer
+Documentation, Core Technologies section.
+
+As an example of scripting an application, the following piece of AppleScript
+will get the name of the frontmost :program:`Finder` window and print it::
+
+   tell application "Finder"
+       get name of window 1
+   end tell
+
+In Python, the following code fragment will do the same::
+
+   import Finder
+
+   f = Finder.Finder()
+   print f.get(f.window(1).name)
+
+As distributed the Python library includes packages that implement the standard
+suites, plus packages that interface to a small number of common applications.
+
+To send AppleEvents to an application you must first create the Python package
+interfacing to the terminology of the application (what :program:`Script Editor`
+calls the "Dictionary"). This can be done from within the :program:`PythonIDE`
+or by running the :file:`gensuitemodule.py` module as a standalone program from
+the command line.
+
+The generated output is a package with a number of modules, one for every suite
+used in the program plus an :mod:`__init__` module to glue it all together. The
+Python inheritance graph follows the AppleScript inheritance graph, so if a
+program's dictionary specifies that it includes support for the Standard Suite,
+but extends one or two verbs with extra arguments then the output suite will
+contain a module :mod:`Standard_Suite` that imports and re-exports everything
+from :mod:`StdSuites.Standard_Suite` but overrides the methods that have extra
+functionality. The output of :mod:`gensuitemodule` is pretty readable, and
+contains the documentation that was in the original AppleScript dictionary in
+Python docstrings, so reading it is a good source of documentation.
+
+The output package implements a main class with the same name as the package
+which contains all the AppleScript verbs as methods, with the direct object as
+the first argument and all optional parameters as keyword arguments. AppleScript
+classes are also implemented as Python classes, as are comparisons and all the
+other thingies.
+
+The main Python class implementing the verbs also allows access to the
+properties and elements declared in the AppleScript class "application". In the
+current release that is as far as the object orientation goes, so in the example
+above we need to use ``f.get(f.window(1).name)`` instead of the more Pythonic
+``f.window(1).name.get()``.
+
+If an AppleScript identifier is not a Python identifier the name is mangled
+according to a small number of rules:
+
+* spaces are replaced with underscores
+
+* other non-alphanumeric characters are replaced with ``_xx_`` where ``xx`` is
+  the hexadecimal character value
+
+* any Python reserved word gets an underscore appended
+
+Python also has support for creating scriptable applications in Python, but The
+following modules are relevant to MacPython AppleScript support:
+
+.. toctree::
+
+   gensuitemodule.rst
+   aetools.rst
+   aepack.rst
+   aetypes.rst
+   miniaeframe.rst
+
+
+In addition, support modules have been pre-generated for :mod:`Finder`,
+:mod:`Terminal`, :mod:`Explorer`, :mod:`Netscape`, :mod:`CodeWarrior`,
+:mod:`SystemEvents` and :mod:`StdSuites`.
diff --git a/Doc/library/macostools.rst b/Doc/library/macostools.rst
new file mode 100644
index 0000000..275100e
--- /dev/null
+++ b/Doc/library/macostools.rst
@@ -0,0 +1,115 @@
+
+:mod:`macostools` --- Convenience routines for file manipulation
+================================================================
+
+.. module:: macostools
+   :platform: Mac
+   :synopsis: Convenience routines for file manipulation.
+
+
+This module contains some convenience routines for file-manipulation on the
+Macintosh. All file parameters can be specified as pathnames, :class:`FSRef` or
+:class:`FSSpec` objects.  This module expects a filesystem which supports forked
+files, so it should not be used on UFS partitions.
+
+The :mod:`macostools` module defines the following functions:
+
+
+.. function:: copy(src, dst[, createpath[, copytimes]])
+
+   Copy file *src* to *dst*.  If *createpath* is non-zero the folders leading to
+   *dst* are created if necessary. The method copies data and resource fork and
+   some finder information (creator, type, flags) and optionally the creation,
+   modification and backup times (default is to copy them). Custom icons, comments
+   and icon position are not copied.
+
+
+.. function:: copytree(src, dst)
+
+   Recursively copy a file tree from *src* to *dst*, creating folders as needed.
+   *src* and *dst* should be specified as pathnames.
+
+
+.. function:: mkalias(src, dst)
+
+   Create a finder alias *dst* pointing to *src*.
+
+
+.. function:: touched(dst)
+
+   Tell the finder that some bits of finder-information such as creator or type for
+   file *dst* has changed. The file can be specified by pathname or fsspec. This
+   call should tell the finder to redraw the files icon.
+
+   .. deprecated:: 2.6
+      The function is a no-op on OS X.
+
+
+.. data:: BUFSIZ
+
+   The buffer size for ``copy``, default 1 megabyte.
+
+Note that the process of creating finder aliases is not specified in the Apple
+documentation. Hence, aliases created with :func:`mkalias` could conceivably
+have incompatible behaviour in some cases.
+
+
+:mod:`findertools` --- The :program:`finder`'s Apple Events interface
+=====================================================================
+
+.. module:: findertools
+   :platform: Mac
+   :synopsis: Wrappers around the finder's Apple Events interface.
+
+
+.. index:: single: AppleEvents
+
+This module contains routines that give Python programs access to some
+functionality provided by the finder. They are implemented as wrappers around
+the AppleEvent interface to the finder.
+
+All file and folder parameters can be specified either as full pathnames, or as
+:class:`FSRef` or :class:`FSSpec` objects.
+
+The :mod:`findertools` module defines the following functions:
+
+
+.. function:: launch(file)
+
+   Tell the finder to launch *file*. What launching means depends on the file:
+   applications are started, folders are opened and documents are opened in the
+   correct application.
+
+
+.. function:: Print(file)
+
+   Tell the finder to print a file. The behaviour is identical to selecting the
+   file and using the print command in the finder's file menu.
+
+
+.. function:: copy(file, destdir)
+
+   Tell the finder to copy a file or folder *file* to folder *destdir*. The
+   function returns an :class:`Alias` object pointing to the new file.
+
+
+.. function:: move(file, destdir)
+
+   Tell the finder to move a file or folder *file* to folder *destdir*. The
+   function returns an :class:`Alias` object pointing to the new file.
+
+
+.. function:: sleep()
+
+   Tell the finder to put the Macintosh to sleep, if your machine supports it.
+
+
+.. function:: restart()
+
+   Tell the finder to perform an orderly restart of the machine.
+
+
+.. function:: shutdown()
+
+   Tell the finder to perform an orderly shutdown of the machine.
+
diff --git a/Doc/library/macpath.rst b/Doc/library/macpath.rst
new file mode 100644
index 0000000..66c54e5
--- /dev/null
+++ b/Doc/library/macpath.rst
@@ -0,0 +1,17 @@
+
+:mod:`macpath` --- MacOS 9 path manipulation functions
+======================================================
+
+.. module:: macpath
+   :synopsis: MacOS 9 path manipulation functions.
+
+
+This module is the Mac OS 9 (and earlier) implementation of the :mod:`os.path`
+module. It can be used to manipulate old-style Macintosh pathnames on Mac OS X
+(or any other platform).
+
+The following functions are available in this module: :func:`normcase`,
+:func:`normpath`, :func:`isabs`, :func:`join`, :func:`split`, :func:`isdir`,
+:func:`isfile`, :func:`walk`, :func:`exists`. For other functions available in
+:mod:`os.path` dummy counterparts are available.
+
diff --git a/Doc/library/mailbox.rst b/Doc/library/mailbox.rst
new file mode 100644
index 0000000..ce8dc59
--- /dev/null
+++ b/Doc/library/mailbox.rst
@@ -0,0 +1,1679 @@
+
+:mod:`mailbox` --- Manipulate mailboxes in various formats
+==========================================================
+
+.. module:: mailbox
+   :synopsis: Manipulate mailboxes in various formats
+.. moduleauthor:: Gregory K. Johnson 
+.. sectionauthor:: Gregory K. Johnson 
+
+
+This module defines two classes, :class:`Mailbox` and :class:`Message`, for
+accessing and manipulating on-disk mailboxes and the messages they contain.
+:class:`Mailbox` offers a dictionary-like mapping from keys to messages.
+:class:`Message` extends the :mod:`email.Message` module's :class:`Message`
+class with format-specific state and behavior. Supported mailbox formats are
+Maildir, mbox, MH, Babyl, and MMDF.
+
+
+.. seealso::
+
+   Module :mod:`email`
+      Represent and manipulate messages.
+
+
+.. _mailbox-objects:
+
+:class:`Mailbox` objects
+------------------------
+
+
+.. class:: Mailbox
+
+   A mailbox, which may be inspected and modified.
+
+The :class:`Mailbox` class defines an interface and is not intended to be
+instantiated.  Instead, format-specific subclasses should inherit from
+:class:`Mailbox` and your code should instantiate a particular subclass.
+
+The :class:`Mailbox` interface is dictionary-like, with small keys corresponding
+to messages. Keys are issued by the :class:`Mailbox` instance with which they
+will be used and are only meaningful to that :class:`Mailbox` instance. A key
+continues to identify a message even if the corresponding message is modified,
+such as by replacing it with another message.
+
+Messages may be added to a :class:`Mailbox` instance using the set-like method
+:meth:`add` and removed using a ``del`` statement or the set-like methods
+:meth:`remove` and :meth:`discard`.
+
+:class:`Mailbox` interface semantics differ from dictionary semantics in some
+noteworthy ways. Each time a message is requested, a new representation
+(typically a :class:`Message` instance) is generated based upon the current
+state of the mailbox. Similarly, when a message is added to a :class:`Mailbox`
+instance, the provided message representation's contents are copied. In neither
+case is a reference to the message representation kept by the :class:`Mailbox`
+instance.
+
+The default :class:`Mailbox` iterator iterates over message representations, not
+keys as the default dictionary iterator does. Moreover, modification of a
+mailbox during iteration is safe and well-defined. Messages added to the mailbox
+after an iterator is created will not be seen by the iterator. Messages removed
+from the mailbox before the iterator yields them will be silently skipped,
+though using a key from an iterator may result in a :exc:`KeyError` exception if
+the corresponding message is subsequently removed.
+
+.. warning::
+
+   Be very cautious when modifying mailboxes that might be simultaneously changed
+   by some other process.  The safest mailbox format to use for such tasks is
+   Maildir; try to avoid using single-file formats such as mbox for concurrent
+   writing.  If you're modifying a mailbox, you *must* lock it by calling the
+   :meth:`lock` and :meth:`unlock` methods *before* reading any messages in the
+   file or making any changes by adding or deleting a message.  Failing to lock the
+   mailbox runs the risk of losing messages or corrupting the entire mailbox.
+
+:class:`Mailbox` instances have the following methods:
+
+
+.. method:: Mailbox.add(message)
+
+   Add *message* to the mailbox and return the key that has been assigned to it.
+
+   Parameter *message* may be a :class:`Message` instance, an
+   :class:`email.Message.Message` instance, a string, or a file-like object (which
+   should be open in text mode). If *message* is an instance of the appropriate
+   format-specific :class:`Message` subclass (e.g., if it's an :class:`mboxMessage`
+   instance and this is an :class:`mbox` instance), its format-specific information
+   is used. Otherwise, reasonable defaults for format-specific information are
+   used.
+
+
+.. method:: Mailbox.remove(key)
+            Mailbox.__delitem__(key)
+            Mailbox.discard(key)
+
+   Delete the message corresponding to *key* from the mailbox.
+
+   If no such message exists, a :exc:`KeyError` exception is raised if the method
+   was called as :meth:`remove` or :meth:`__delitem__` but no exception is raised
+   if the method was called as :meth:`discard`. The behavior of :meth:`discard` may
+   be preferred if the underlying mailbox format supports concurrent modification
+   by other processes.
+
+
+.. method:: Mailbox.__setitem__(key, message)
+
+   Replace the message corresponding to *key* with *message*. Raise a
+   :exc:`KeyError` exception if no message already corresponds to *key*.
+
+   As with :meth:`add`, parameter *message* may be a :class:`Message` instance, an
+   :class:`email.Message.Message` instance, a string, or a file-like object (which
+   should be open in text mode). If *message* is an instance of the appropriate
+   format-specific :class:`Message` subclass (e.g., if it's an :class:`mboxMessage`
+   instance and this is an :class:`mbox` instance), its format-specific information
+   is used. Otherwise, the format-specific information of the message that
+   currently corresponds to *key* is left unchanged.
+
+
+.. method:: Mailbox.iterkeys()
+            Mailbox.keys()
+
+   Return an iterator over all keys if called as :meth:`iterkeys` or return a list
+   of keys if called as :meth:`keys`.
+
+
+.. method:: Mailbox.itervalues()
+            Mailbox.__iter__()
+            Mailbox.values()
+
+   Return an iterator over representations of all messages if called as
+   :meth:`itervalues` or :meth:`__iter__` or return a list of such representations
+   if called as :meth:`values`. The messages are represented as instances of the
+   appropriate format-specific :class:`Message` subclass unless a custom message
+   factory was specified when the :class:`Mailbox` instance was initialized.
+
+   .. note::
+
+      The behavior of :meth:`__iter__` is unlike that of dictionaries, which iterate
+      over keys.
+
+
+.. method:: Mailbox.iteritems()
+            Mailbox.items()
+
+   Return an iterator over (*key*, *message*) pairs, where *key* is a key and
+   *message* is a message representation, if called as :meth:`iteritems` or return
+   a list of such pairs if called as :meth:`items`. The messages are represented as
+   instances of the appropriate format-specific :class:`Message` subclass unless a
+   custom message factory was specified when the :class:`Mailbox` instance was
+   initialized.
+
+
+.. method:: Mailbox.get(key[, default=None])
+            Mailbox.__getitem__(key)
+
+   Return a representation of the message corresponding to *key*. If no such
+   message exists, *default* is returned if the method was called as :meth:`get`
+   and a :exc:`KeyError` exception is raised if the method was called as
+   :meth:`__getitem__`. The message is represented as an instance of the
+   appropriate format-specific :class:`Message` subclass unless a custom message
+   factory was specified when the :class:`Mailbox` instance was initialized.
+
+
+.. method:: Mailbox.get_message(key)
+
+   Return a representation of the message corresponding to *key* as an instance of
+   the appropriate format-specific :class:`Message` subclass, or raise a
+   :exc:`KeyError` exception if no such message exists.
+
+
+.. method:: Mailbox.get_string(key)
+
+   Return a string representation of the message corresponding to *key*, or raise a
+   :exc:`KeyError` exception if no such message exists.
+
+
+.. method:: Mailbox.get_file(key)
+
+   Return a file-like representation of the message corresponding to *key*, or
+   raise a :exc:`KeyError` exception if no such message exists. The file-like
+   object behaves as if open in binary mode. This file should be closed once it is
+   no longer needed.
+
+   .. note::
+
+      Unlike other representations of messages, file-like representations are not
+      necessarily independent of the :class:`Mailbox` instance that created them or of
+      the underlying mailbox. More specific documentation is provided by each
+      subclass.
+
+
+.. method:: Mailbox.has_key(key)
+            Mailbox.__contains__(key)
+
+   Return ``True`` if *key* corresponds to a message, ``False`` otherwise.
+
+
+.. method:: Mailbox.__len__()
+
+   Return a count of messages in the mailbox.
+
+
+.. method:: Mailbox.clear()
+
+   Delete all messages from the mailbox.
+
+
+.. method:: Mailbox.pop(key[, default])
+
+   Return a representation of the message corresponding to *key* and delete the
+   message. If no such message exists, return *default* if it was supplied or else
+   raise a :exc:`KeyError` exception. The message is represented as an instance of
+   the appropriate format-specific :class:`Message` subclass unless a custom
+   message factory was specified when the :class:`Mailbox` instance was
+   initialized.
+
+
+.. method:: Mailbox.popitem()
+
+   Return an arbitrary (*key*, *message*) pair, where *key* is a key and *message*
+   is a message representation, and delete the corresponding message. If the
+   mailbox is empty, raise a :exc:`KeyError` exception. The message is represented
+   as an instance of the appropriate format-specific :class:`Message` subclass
+   unless a custom message factory was specified when the :class:`Mailbox` instance
+   was initialized.
+
+
+.. method:: Mailbox.update(arg)
+
+   Parameter *arg* should be a *key*-to-*message* mapping or an iterable of (*key*,
+   *message*) pairs. Updates the mailbox so that, for each given *key* and
+   *message*, the message corresponding to *key* is set to *message* as if by using
+   :meth:`__setitem__`. As with :meth:`__setitem__`, each *key* must already
+   correspond to a message in the mailbox or else a :exc:`KeyError` exception will
+   be raised, so in general it is incorrect for *arg* to be a :class:`Mailbox`
+   instance.
+
+   .. note::
+
+      Unlike with dictionaries, keyword arguments are not supported.
+
+
+.. method:: Mailbox.flush()
+
+   Write any pending changes to the filesystem. For some :class:`Mailbox`
+   subclasses, changes are always written immediately and :meth:`flush` does
+   nothing, but you should still make a habit of calling this method.
+
+
+.. method:: Mailbox.lock()
+
+   Acquire an exclusive advisory lock on the mailbox so that other processes know
+   not to modify it. An :exc:`ExternalClashError` is raised if the lock is not
+   available. The particular locking mechanisms used depend upon the mailbox
+   format.  You should *always* lock the mailbox before making any  modifications
+   to its contents.
+
+
+.. method:: Mailbox.unlock()
+
+   Release the lock on the mailbox, if any.
+
+
+.. method:: Mailbox.close()
+
+   Flush the mailbox, unlock it if necessary, and close any open files. For some
+   :class:`Mailbox` subclasses, this method does nothing.
+
+
+.. _mailbox-maildir:
+
+:class:`Maildir`
+^^^^^^^^^^^^^^^^
+
+
+.. class:: Maildir(dirname[, factory=rfc822.Message[, create=True]])
+
+   A subclass of :class:`Mailbox` for mailboxes in Maildir format. Parameter
+   *factory* is a callable object that accepts a file-like message representation
+   (which behaves as if opened in binary mode) and returns a custom representation.
+   If *factory* is ``None``, :class:`MaildirMessage` is used as the default message
+   representation. If *create* is ``True``, the mailbox is created if it does not
+   exist.
+
+   It is for historical reasons that *factory* defaults to :class:`rfc822.Message`
+   and that *dirname* is named as such rather than *path*. For a :class:`Maildir`
+   instance that behaves like instances of other :class:`Mailbox` subclasses, set
+   *factory* to ``None``.
+
+Maildir is a directory-based mailbox format invented for the qmail mail transfer
+agent and now widely supported by other programs. Messages in a Maildir mailbox
+are stored in separate files within a common directory structure. This design
+allows Maildir mailboxes to be accessed and modified by multiple unrelated
+programs without data corruption, so file locking is unnecessary.
+
+Maildir mailboxes contain three subdirectories, namely: :file:`tmp`,
+:file:`new`, and :file:`cur`. Messages are created momentarily in the
+:file:`tmp` subdirectory and then moved to the :file:`new` subdirectory to
+finalize delivery. A mail user agent may subsequently move the message to the
+:file:`cur` subdirectory and store information about the state of the message in
+a special "info" section appended to its file name.
+
+Folders of the style introduced by the Courier mail transfer agent are also
+supported. Any subdirectory of the main mailbox is considered a folder if
+``'.'`` is the first character in its name. Folder names are represented by
+:class:`Maildir` without the leading ``'.'``. Each folder is itself a Maildir
+mailbox but should not contain other folders. Instead, a logical nesting is
+indicated using ``'.'`` to delimit levels, e.g., "Archived.2005.07".
+
+.. note::
+
+   The Maildir specification requires the use of a colon (``':'``) in certain
+   message file names. However, some operating systems do not permit this character
+   in file names, If you wish to use a Maildir-like format on such an operating
+   system, you should specify another character to use instead. The exclamation
+   point (``'!'``) is a popular choice. For example::
+
+      import mailbox
+      mailbox.Maildir.colon = '!'
+
+   The :attr:`colon` attribute may also be set on a per-instance basis.
+
+:class:`Maildir` instances have all of the methods of :class:`Mailbox` in
+addition to the following:
+
+
+.. method:: Maildir.list_folders()
+
+   Return a list of the names of all folders.
+
+
+.. method:: Maildir.get_folder(folder)
+
+   Return a :class:`Maildir` instance representing the folder whose name is
+   *folder*. A :exc:`NoSuchMailboxError` exception is raised if the folder does not
+   exist.
+
+
+.. method:: Maildir.add_folder(folder)
+
+   Create a folder whose name is *folder* and return a :class:`Maildir` instance
+   representing it.
+
+
+.. method:: Maildir.remove_folder(folder)
+
+   Delete the folder whose name is *folder*. If the folder contains any messages, a
+   :exc:`NotEmptyError` exception will be raised and the folder will not be
+   deleted.
+
+
+.. method:: Maildir.clean()
+
+   Delete temporary files from the mailbox that have not been accessed in the last
+   36 hours. The Maildir specification says that mail-reading programs should do
+   this occasionally.
+
+Some :class:`Mailbox` methods implemented by :class:`Maildir` deserve special
+remarks:
+
+
+.. method:: Maildir.add(message)
+            Maildir.__setitem__(key, message)
+            Maildir.update(arg)
+
+   .. warning::
+
+      These methods generate unique file names based upon the current process ID. When
+      using multiple threads, undetected name clashes may occur and cause corruption
+      of the mailbox unless threads are coordinated to avoid using these methods to
+      manipulate the same mailbox simultaneously.
+
+
+.. method:: Maildir.flush()
+
+   All changes to Maildir mailboxes are immediately applied, so this method does
+   nothing.
+
+
+.. method:: Maildir.lock()
+            Maildir.unlock()
+
+   Maildir mailboxes do not support (or require) locking, so these methods do
+   nothing.
+
+
+.. method:: Maildir.close()
+
+   :class:`Maildir` instances do not keep any open files and the underlying
+   mailboxes do not support locking, so this method does nothing.
+
+
+.. method:: Maildir.get_file(key)
+
+   Depending upon the host platform, it may not be possible to modify or remove the
+   underlying message while the returned file remains open.
+
+
+.. seealso::
+
+   `maildir man page from qmail `_
+      The original specification of the format.
+
+   `Using maildir format `_
+      Notes on Maildir by its inventor. Includes an updated name-creation scheme and
+      details on "info" semantics.
+
+   `maildir man page from Courier `_
+      Another specification of the format. Describes a common extension for supporting
+      folders.
+
+
+.. _mailbox-mbox:
+
+:class:`mbox`
+^^^^^^^^^^^^^
+
+
+.. class:: mbox(path[, factory=None[, create=True]])
+
+   A subclass of :class:`Mailbox` for mailboxes in mbox format. Parameter *factory*
+   is a callable object that accepts a file-like message representation (which
+   behaves as if opened in binary mode) and returns a custom representation. If
+   *factory* is ``None``, :class:`mboxMessage` is used as the default message
+   representation. If *create* is ``True``, the mailbox is created if it does not
+   exist.
+
+The mbox format is the classic format for storing mail on Unix systems. All
+messages in an mbox mailbox are stored in a single file with the beginning of
+each message indicated by a line whose first five characters are "From ".
+
+Several variations of the mbox format exist to address perceived shortcomings in
+the original. In the interest of compatibility, :class:`mbox` implements the
+original format, which is sometimes referred to as :dfn:`mboxo`. This means that
+the :mailheader:`Content-Length` header, if present, is ignored and that any
+occurrences of "From " at the beginning of a line in a message body are
+transformed to ">From " when storing the message, although occurences of ">From
+" are not transformed to "From " when reading the message.
+
+Some :class:`Mailbox` methods implemented by :class:`mbox` deserve special
+remarks:
+
+
+.. method:: mbox.get_file(key)
+
+   Using the file after calling :meth:`flush` or :meth:`close` on the :class:`mbox`
+   instance may yield unpredictable results or raise an exception.
+
+
+.. method:: mbox.lock()
+            mbox.unlock()
+
+   Three locking mechanisms are used---dot locking and, if available, the
+   :cfunc:`flock` and :cfunc:`lockf` system calls.
+
+
+.. seealso::
+
+   `mbox man page from qmail `_
+      A specification of the format and its variations.
+
+   `mbox man page from tin `_
+      Another specification of the format, with details on locking.
+
+   `Configuring Netscape Mail on Unix: Why The Content-Length Format is Bad `_
+      An argument for using the original mbox format rather than a variation.
+
+   `"mbox" is a family of several mutually incompatible mailbox formats `_
+      A history of mbox variations.
+
+
+.. _mailbox-mh:
+
+:class:`MH`
+^^^^^^^^^^^
+
+
+.. class:: MH(path[, factory=None[, create=True]])
+
+   A subclass of :class:`Mailbox` for mailboxes in MH format. Parameter *factory*
+   is a callable object that accepts a file-like message representation (which
+   behaves as if opened in binary mode) and returns a custom representation. If
+   *factory* is ``None``, :class:`MHMessage` is used as the default message
+   representation. If *create* is ``True``, the mailbox is created if it does not
+   exist.
+
+MH is a directory-based mailbox format invented for the MH Message Handling
+System, a mail user agent. Each message in an MH mailbox resides in its own
+file. An MH mailbox may contain other MH mailboxes (called :dfn:`folders`) in
+addition to messages. Folders may be nested indefinitely. MH mailboxes also
+support :dfn:`sequences`, which are named lists used to logically group messages
+without moving them to sub-folders. Sequences are defined in a file called
+:file:`.mh_sequences` in each folder.
+
+The :class:`MH` class manipulates MH mailboxes, but it does not attempt to
+emulate all of :program:`mh`'s behaviors. In particular, it does not modify and
+is not affected by the :file:`context` or :file:`.mh_profile` files that are
+used by :program:`mh` to store its state and configuration.
+
+:class:`MH` instances have all of the methods of :class:`Mailbox` in addition to
+the following:
+
+
+.. method:: MH.list_folders()
+
+   Return a list of the names of all folders.
+
+
+.. method:: MH.get_folder(folder)
+
+   Return an :class:`MH` instance representing the folder whose name is *folder*. A
+   :exc:`NoSuchMailboxError` exception is raised if the folder does not exist.
+
+
+.. method:: MH.add_folder(folder)
+
+   Create a folder whose name is *folder* and return an :class:`MH` instance
+   representing it.
+
+
+.. method:: MH.remove_folder(folder)
+
+   Delete the folder whose name is *folder*. If the folder contains any messages, a
+   :exc:`NotEmptyError` exception will be raised and the folder will not be
+   deleted.
+
+
+.. method:: MH.get_sequences()
+
+   Return a dictionary of sequence names mapped to key lists. If there are no
+   sequences, the empty dictionary is returned.
+
+
+.. method:: MH.set_sequences(sequences)
+
+   Re-define the sequences that exist in the mailbox based upon *sequences*, a
+   dictionary of names mapped to key lists, like returned by :meth:`get_sequences`.
+
+
+.. method:: MH.pack()
+
+   Rename messages in the mailbox as necessary to eliminate gaps in numbering.
+   Entries in the sequences list are updated correspondingly.
+
+   .. note::
+
+      Already-issued keys are invalidated by this operation and should not be
+      subsequently used.
+
+Some :class:`Mailbox` methods implemented by :class:`MH` deserve special
+remarks:
+
+
+.. method:: MH.remove(key)
+            MH.__delitem__(key)
+            MH.discard(key)
+
+   These methods immediately delete the message. The MH convention of marking a
+   message for deletion by prepending a comma to its name is not used.
+
+
+.. method:: MH.lock()
+            MH.unlock()
+
+   Three locking mechanisms are used---dot locking and, if available, the
+   :cfunc:`flock` and :cfunc:`lockf` system calls. For MH mailboxes, locking the
+   mailbox means locking the :file:`.mh_sequences` file and, only for the duration
+   of any operations that affect them, locking individual message files.
+
+
+.. method:: MH.get_file(key)
+
+   Depending upon the host platform, it may not be possible to remove the
+   underlying message while the returned file remains open.
+
+
+.. method:: MH.flush()
+
+   All changes to MH mailboxes are immediately applied, so this method does
+   nothing.
+
+
+.. method:: MH.close()
+
+   :class:`MH` instances do not keep any open files, so this method is equivelant
+   to :meth:`unlock`.
+
+
+.. seealso::
+
+   `nmh - Message Handling System `_
+      Home page of :program:`nmh`, an updated version of the original :program:`mh`.
+
+   `MH & nmh: Email for Users & Programmers `_
+      A GPL-licensed book on :program:`mh` and :program:`nmh`, with some information
+      on the mailbox format.
+
+
+.. _mailbox-babyl:
+
+:class:`Babyl`
+^^^^^^^^^^^^^^
+
+
+.. class:: Babyl(path[, factory=None[, create=True]])
+
+   A subclass of :class:`Mailbox` for mailboxes in Babyl format. Parameter
+   *factory* is a callable object that accepts a file-like message representation
+   (which behaves as if opened in binary mode) and returns a custom representation.
+   If *factory* is ``None``, :class:`BabylMessage` is used as the default message
+   representation. If *create* is ``True``, the mailbox is created if it does not
+   exist.
+
+Babyl is a single-file mailbox format used by the Rmail mail user agent included
+with Emacs. The beginning of a message is indicated by a line containing the two
+characters Control-Underscore (``'\037'``) and Control-L (``'\014'``). The end
+of a message is indicated by the start of the next message or, in the case of
+the last message, a line containing a Control-Underscore (``'\037'``)
+character.
+
+Messages in a Babyl mailbox have two sets of headers, original headers and
+so-called visible headers. Visible headers are typically a subset of the
+original headers that have been reformatted or abridged to be more
+attractive. Each message in a Babyl mailbox also has an accompanying list of
+:dfn:`labels`, or short strings that record extra information about the message,
+and a list of all user-defined labels found in the mailbox is kept in the Babyl
+options section.
+
+:class:`Babyl` instances have all of the methods of :class:`Mailbox` in addition
+to the following:
+
+
+.. method:: Babyl.get_labels()
+
+   Return a list of the names of all user-defined labels used in the mailbox.
+
+   .. note::
+
+      The actual messages are inspected to determine which labels exist in the mailbox
+      rather than consulting the list of labels in the Babyl options section, but the
+      Babyl section is updated whenever the mailbox is modified.
+
+Some :class:`Mailbox` methods implemented by :class:`Babyl` deserve special
+remarks:
+
+
+.. method:: Babyl.get_file(key)
+
+   In Babyl mailboxes, the headers of a message are not stored contiguously with
+   the body of the message. To generate a file-like representation, the headers and
+   body are copied together into a :class:`StringIO` instance (from the
+   :mod:`StringIO` module), which has an API identical to that of a file. As a
+   result, the file-like object is truly independent of the underlying mailbox but
+   does not save memory compared to a string representation.
+
+
+.. method:: Babyl.lock()
+            Babyl.unlock()
+
+   Three locking mechanisms are used---dot locking and, if available, the
+   :cfunc:`flock` and :cfunc:`lockf` system calls.
+
+
+.. seealso::
+
+   `Format of Version 5 Babyl Files `_
+      A specification of the Babyl format.
+
+   `Reading Mail with Rmail `_
+      The Rmail manual, with some information on Babyl semantics.
+
+
+.. _mailbox-mmdf:
+
+:class:`MMDF`
+^^^^^^^^^^^^^
+
+
+.. class:: MMDF(path[, factory=None[, create=True]])
+
+   A subclass of :class:`Mailbox` for mailboxes in MMDF format. Parameter *factory*
+   is a callable object that accepts a file-like message representation (which
+   behaves as if opened in binary mode) and returns a custom representation. If
+   *factory* is ``None``, :class:`MMDFMessage` is used as the default message
+   representation. If *create* is ``True``, the mailbox is created if it does not
+   exist.
+
+MMDF is a single-file mailbox format invented for the Multichannel Memorandum
+Distribution Facility, a mail transfer agent. Each message is in the same form
+as an mbox message but is bracketed before and after by lines containing four
+Control-A (``'\001'``) characters. As with the mbox format, the beginning of
+each message is indicated by a line whose first five characters are "From ", but
+additional occurrences of "From " are not transformed to ">From " when storing
+messages because the extra message separator lines prevent mistaking such
+occurrences for the starts of subsequent messages.
+
+Some :class:`Mailbox` methods implemented by :class:`MMDF` deserve special
+remarks:
+
+
+.. method:: MMDF.get_file(key)
+
+   Using the file after calling :meth:`flush` or :meth:`close` on the :class:`MMDF`
+   instance may yield unpredictable results or raise an exception.
+
+
+.. method:: MMDF.lock()
+            MMDF.unlock()
+
+   Three locking mechanisms are used---dot locking and, if available, the
+   :cfunc:`flock` and :cfunc:`lockf` system calls.
+
+
+.. seealso::
+
+   `mmdf man page from tin `_
+      A specification of MMDF format from the documentation of tin, a newsreader.
+
+   `MMDF `_
+      A Wikipedia article describing the Multichannel Memorandum Distribution
+      Facility.
+
+
+.. _mailbox-message-objects:
+
+:class:`Message` objects
+------------------------
+
+
+.. class:: Message([message])
+
+   A subclass of the :mod:`email.Message` module's :class:`Message`. Subclasses of
+   :class:`mailbox.Message` add mailbox-format-specific state and behavior.
+
+   If *message* is omitted, the new instance is created in a default, empty state.
+   If *message* is an :class:`email.Message.Message` instance, its contents are
+   copied; furthermore, any format-specific information is converted insofar as
+   possible if *message* is a :class:`Message` instance. If *message* is a string
+   or a file, it should contain an :rfc:`2822`\ -compliant message, which is read
+   and parsed.
+
+The format-specific state and behaviors offered by subclasses vary, but in
+general it is only the properties that are not specific to a particular mailbox
+that are supported (although presumably the properties are specific to a
+particular mailbox format). For example, file offsets for single-file mailbox
+formats and file names for directory-based mailbox formats are not retained,
+because they are only applicable to the original mailbox. But state such as
+whether a message has been read by the user or marked as important is retained,
+because it applies to the message itself.
+
+There is no requirement that :class:`Message` instances be used to represent
+messages retrieved using :class:`Mailbox` instances. In some situations, the
+time and memory required to generate :class:`Message` representations might not
+not acceptable. For such situations, :class:`Mailbox` instances also offer
+string and file-like representations, and a custom message factory may be
+specified when a :class:`Mailbox` instance is initialized.
+
+
+.. _mailbox-maildirmessage:
+
+:class:`MaildirMessage`
+^^^^^^^^^^^^^^^^^^^^^^^
+
+
+.. class:: MaildirMessage([message])
+
+   A message with Maildir-specific behaviors. Parameter *message* has the same
+   meaning as with the :class:`Message` constructor.
+
+Typically, a mail user agent application moves all of the messages in the
+:file:`new` subdirectory to the :file:`cur` subdirectory after the first time
+the user opens and closes the mailbox, recording that the messages are old
+whether or not they've actually been read. Each message in :file:`cur` has an
+"info" section added to its file name to store information about its state.
+(Some mail readers may also add an "info" section to messages in :file:`new`.)
+The "info" section may take one of two forms: it may contain "2," followed by a
+list of standardized flags (e.g., "2,FR") or it may contain "1," followed by
+so-called experimental information. Standard flags for Maildir messages are as
+follows:
+
++------+---------+--------------------------------+
+| Flag | Meaning | Explanation                    |
++======+=========+================================+
+| D    | Draft   | Under composition              |
++------+---------+--------------------------------+
+| F    | Flagged | Marked as important            |
++------+---------+--------------------------------+
+| P    | Passed  | Forwarded, resent, or bounced  |
++------+---------+--------------------------------+
+| R    | Replied | Replied to                     |
++------+---------+--------------------------------+
+| S    | Seen    | Read                           |
++------+---------+--------------------------------+
+| T    | Trashed | Marked for subsequent deletion |
++------+---------+--------------------------------+
+
+:class:`MaildirMessage` instances offer the following methods:
+
+
+.. method:: MaildirMessage.get_subdir()
+
+   Return either "new" (if the message should be stored in the :file:`new`
+   subdirectory) or "cur" (if the message should be stored in the :file:`cur`
+   subdirectory).
+
+   .. note::
+
+      A message is typically moved from :file:`new` to :file:`cur` after its mailbox
+      has been accessed, whether or not the message is has been read. A message
+      ``msg`` has been read if ``"S" not in msg.get_flags()`` is ``True``.
+
+
+.. method:: MaildirMessage.set_subdir(subdir)
+
+   Set the subdirectory the message should be stored in. Parameter *subdir* must be
+   either "new" or "cur".
+
+
+.. method:: MaildirMessage.get_flags()
+
+   Return a string specifying the flags that are currently set. If the message
+   complies with the standard Maildir format, the result is the concatenation in
+   alphabetical order of zero or one occurrence of each of ``'D'``, ``'F'``,
+   ``'P'``, ``'R'``, ``'S'``, and ``'T'``. The empty string is returned if no flags
+   are set or if "info" contains experimental semantics.
+
+
+.. method:: MaildirMessage.set_flags(flags)
+
+   Set the flags specified by *flags* and unset all others.
+
+
+.. method:: MaildirMessage.add_flag(flag)
+
+   Set the flag(s) specified by *flag* without changing other flags. To add more
+   than one flag at a time, *flag* may be a string of more than one character. The
+   current "info" is overwritten whether or not it contains experimental
+   information rather than flags.
+
+
+.. method:: MaildirMessage.remove_flag(flag)
+
+   Unset the flag(s) specified by *flag* without changing other flags. To remove
+   more than one flag at a time, *flag* maybe a string of more than one character.
+   If "info" contains experimental information rather than flags, the current
+   "info" is not modified.
+
+
+.. method:: MaildirMessage.get_date()
+
+   Return the delivery date of the message as a floating-point number representing
+   seconds since the epoch.
+
+
+.. method:: MaildirMessage.set_date(date)
+
+   Set the delivery date of the message to *date*, a floating-point number
+   representing seconds since the epoch.
+
+
+.. method:: MaildirMessage.get_info()
+
+   Return a string containing the "info" for a message. This is useful for
+   accessing and modifying "info" that is experimental (i.e., not a list of flags).
+
+
+.. method:: MaildirMessage.set_info(info)
+
+   Set "info" to *info*, which should be a string.
+
+When a :class:`MaildirMessage` instance is created based upon an
+:class:`mboxMessage` or :class:`MMDFMessage` instance, the :mailheader:`Status`
+and :mailheader:`X-Status` headers are omitted and the following conversions
+take place:
+
++--------------------+----------------------------------------------+
+| Resulting state    | :class:`mboxMessage` or :class:`MMDFMessage` |
+|                    | state                                        |
++====================+==============================================+
+| "cur" subdirectory | O flag                                       |
++--------------------+----------------------------------------------+
+| F flag             | F flag                                       |
++--------------------+----------------------------------------------+
+| R flag             | A flag                                       |
++--------------------+----------------------------------------------+
+| S flag             | R flag                                       |
++--------------------+----------------------------------------------+
+| T flag             | D flag                                       |
++--------------------+----------------------------------------------+
+
+When a :class:`MaildirMessage` instance is created based upon an
+:class:`MHMessage` instance, the following conversions take place:
+
++-------------------------------+--------------------------+
+| Resulting state               | :class:`MHMessage` state |
++===============================+==========================+
+| "cur" subdirectory            | "unseen" sequence        |
++-------------------------------+--------------------------+
+| "cur" subdirectory and S flag | no "unseen" sequence     |
++-------------------------------+--------------------------+
+| F flag                        | "flagged" sequence       |
++-------------------------------+--------------------------+
+| R flag                        | "replied" sequence       |
++-------------------------------+--------------------------+
+
+When a :class:`MaildirMessage` instance is created based upon a
+:class:`BabylMessage` instance, the following conversions take place:
+
++-------------------------------+-------------------------------+
+| Resulting state               | :class:`BabylMessage` state   |
++===============================+===============================+
+| "cur" subdirectory            | "unseen" label                |
++-------------------------------+-------------------------------+
+| "cur" subdirectory and S flag | no "unseen" label             |
++-------------------------------+-------------------------------+
+| P flag                        | "forwarded" or "resent" label |
++-------------------------------+-------------------------------+
+| R flag                        | "answered" label              |
++-------------------------------+-------------------------------+
+| T flag                        | "deleted" label               |
++-------------------------------+-------------------------------+
+
+
+.. _mailbox-mboxmessage:
+
+:class:`mboxMessage`
+^^^^^^^^^^^^^^^^^^^^
+
+
+.. class:: mboxMessage([message])
+
+   A message with mbox-specific behaviors. Parameter *message* has the same meaning
+   as with the :class:`Message` constructor.
+
+Messages in an mbox mailbox are stored together in a single file. The sender's
+envelope address and the time of delivery are typically stored in a line
+beginning with "From " that is used to indicate the start of a message, though
+there is considerable variation in the exact format of this data among mbox
+implementations. Flags that indicate the state of the message, such as whether
+it has been read or marked as important, are typically stored in
+:mailheader:`Status` and :mailheader:`X-Status` headers.
+
+Conventional flags for mbox messages are as follows:
+
++------+----------+--------------------------------+
+| Flag | Meaning  | Explanation                    |
++======+==========+================================+
+| R    | Read     | Read                           |
++------+----------+--------------------------------+
+| O    | Old      | Previously detected by MUA     |
++------+----------+--------------------------------+
+| D    | Deleted  | Marked for subsequent deletion |
++------+----------+--------------------------------+
+| F    | Flagged  | Marked as important            |
++------+----------+--------------------------------+
+| A    | Answered | Replied to                     |
++------+----------+--------------------------------+
+
+The "R" and "O" flags are stored in the :mailheader:`Status` header, and the
+"D", "F", and "A" flags are stored in the :mailheader:`X-Status` header. The
+flags and headers typically appear in the order mentioned.
+
+:class:`mboxMessage` instances offer the following methods:
+
+
+.. method:: mboxMessage.get_from()
+
+   Return a string representing the "From " line that marks the start of the
+   message in an mbox mailbox. The leading "From " and the trailing newline are
+   excluded.
+
+
+.. method:: mboxMessage.set_from(from_[, time_=None])
+
+   Set the "From " line to *from_*, which should be specified without a leading
+   "From " or trailing newline. For convenience, *time_* may be specified and will
+   be formatted appropriately and appended to *from_*. If *time_* is specified, it
+   should be a :class:`struct_time` instance, a tuple suitable for passing to
+   :meth:`time.strftime`, or ``True`` (to use :meth:`time.gmtime`).
+
+
+.. method:: mboxMessage.get_flags()
+
+   Return a string specifying the flags that are currently set. If the message
+   complies with the conventional format, the result is the concatenation in the
+   following order of zero or one occurrence of each of ``'R'``, ``'O'``, ``'D'``,
+   ``'F'``, and ``'A'``.
+
+
+.. method:: mboxMessage.set_flags(flags)
+
+   Set the flags specified by *flags* and unset all others. Parameter *flags*
+   should be the concatenation in any order of zero or more occurrences of each of
+   ``'R'``, ``'O'``, ``'D'``, ``'F'``, and ``'A'``.
+
+
+.. method:: mboxMessage.add_flag(flag)
+
+   Set the flag(s) specified by *flag* without changing other flags. To add more
+   than one flag at a time, *flag* may be a string of more than one character.
+
+
+.. method:: mboxMessage.remove_flag(flag)
+
+   Unset the flag(s) specified by *flag* without changing other flags. To remove
+   more than one flag at a time, *flag* maybe a string of more than one character.
+
+When an :class:`mboxMessage` instance is created based upon a
+:class:`MaildirMessage` instance, a "From " line is generated based upon the
+:class:`MaildirMessage` instance's delivery date, and the following conversions
+take place:
+
++-----------------+-------------------------------+
+| Resulting state | :class:`MaildirMessage` state |
++=================+===============================+
+| R flag          | S flag                        |
++-----------------+-------------------------------+
+| O flag          | "cur" subdirectory            |
++-----------------+-------------------------------+
+| D flag          | T flag                        |
++-----------------+-------------------------------+
+| F flag          | F flag                        |
++-----------------+-------------------------------+
+| A flag          | R flag                        |
++-----------------+-------------------------------+
+
+When an :class:`mboxMessage` instance is created based upon an
+:class:`MHMessage` instance, the following conversions take place:
+
++-------------------+--------------------------+
+| Resulting state   | :class:`MHMessage` state |
++===================+==========================+
+| R flag and O flag | no "unseen" sequence     |
++-------------------+--------------------------+
+| O flag            | "unseen" sequence        |
++-------------------+--------------------------+
+| F flag            | "flagged" sequence       |
++-------------------+--------------------------+
+| A flag            | "replied" sequence       |
++-------------------+--------------------------+
+
+When an :class:`mboxMessage` instance is created based upon a
+:class:`BabylMessage` instance, the following conversions take place:
+
++-------------------+-----------------------------+
+| Resulting state   | :class:`BabylMessage` state |
++===================+=============================+
+| R flag and O flag | no "unseen" label           |
++-------------------+-----------------------------+
+| O flag            | "unseen" label              |
++-------------------+-----------------------------+
+| D flag            | "deleted" label             |
++-------------------+-----------------------------+
+| A flag            | "answered" label            |
++-------------------+-----------------------------+
+
+When a :class:`Message` instance is created based upon an :class:`MMDFMessage`
+instance, the "From " line is copied and all flags directly correspond:
+
++-----------------+----------------------------+
+| Resulting state | :class:`MMDFMessage` state |
++=================+============================+
+| R flag          | R flag                     |
++-----------------+----------------------------+
+| O flag          | O flag                     |
++-----------------+----------------------------+
+| D flag          | D flag                     |
++-----------------+----------------------------+
+| F flag          | F flag                     |
++-----------------+----------------------------+
+| A flag          | A flag                     |
++-----------------+----------------------------+
+
+
+.. _mailbox-mhmessage:
+
+:class:`MHMessage`
+^^^^^^^^^^^^^^^^^^
+
+
+.. class:: MHMessage([message])
+
+   A message with MH-specific behaviors. Parameter *message* has the same meaning
+   as with the :class:`Message` constructor.
+
+MH messages do not support marks or flags in the traditional sense, but they do
+support sequences, which are logical groupings of arbitrary messages. Some mail
+reading programs (although not the standard :program:`mh` and :program:`nmh`)
+use sequences in much the same way flags are used with other formats, as
+follows:
+
++----------+------------------------------------------+
+| Sequence | Explanation                              |
++==========+==========================================+
+| unseen   | Not read, but previously detected by MUA |
++----------+------------------------------------------+
+| replied  | Replied to                               |
++----------+------------------------------------------+
+| flagged  | Marked as important                      |
++----------+------------------------------------------+
+
+:class:`MHMessage` instances offer the following methods:
+
+
+.. method:: MHMessage.get_sequences()
+
+   Return a list of the names of sequences that include this message.
+
+
+.. method:: MHMessage.set_sequences(sequences)
+
+   Set the list of sequences that include this message.
+
+
+.. method:: MHMessage.add_sequence(sequence)
+
+   Add *sequence* to the list of sequences that include this message.
+
+
+.. method:: MHMessage.remove_sequence(sequence)
+
+   Remove *sequence* from the list of sequences that include this message.
+
+When an :class:`MHMessage` instance is created based upon a
+:class:`MaildirMessage` instance, the following conversions take place:
+
++--------------------+-------------------------------+
+| Resulting state    | :class:`MaildirMessage` state |
++====================+===============================+
+| "unseen" sequence  | no S flag                     |
++--------------------+-------------------------------+
+| "replied" sequence | R flag                        |
++--------------------+-------------------------------+
+| "flagged" sequence | F flag                        |
++--------------------+-------------------------------+
+
+When an :class:`MHMessage` instance is created based upon an
+:class:`mboxMessage` or :class:`MMDFMessage` instance, the :mailheader:`Status`
+and :mailheader:`X-Status` headers are omitted and the following conversions
+take place:
+
++--------------------+----------------------------------------------+
+| Resulting state    | :class:`mboxMessage` or :class:`MMDFMessage` |
+|                    | state                                        |
++====================+==============================================+
+| "unseen" sequence  | no R flag                                    |
++--------------------+----------------------------------------------+
+| "replied" sequence | A flag                                       |
++--------------------+----------------------------------------------+
+| "flagged" sequence | F flag                                       |
++--------------------+----------------------------------------------+
+
+When an :class:`MHMessage` instance is created based upon a
+:class:`BabylMessage` instance, the following conversions take place:
+
++--------------------+-----------------------------+
+| Resulting state    | :class:`BabylMessage` state |
++====================+=============================+
+| "unseen" sequence  | "unseen" label              |
++--------------------+-----------------------------+
+| "replied" sequence | "answered" label            |
++--------------------+-----------------------------+
+
+
+.. _mailbox-babylmessage:
+
+:class:`BabylMessage`
+^^^^^^^^^^^^^^^^^^^^^
+
+
+.. class:: BabylMessage([message])
+
+   A message with Babyl-specific behaviors. Parameter *message* has the same
+   meaning as with the :class:`Message` constructor.
+
+Certain message labels, called :dfn:`attributes`, are defined by convention to
+have special meanings. The attributes are as follows:
+
++-----------+------------------------------------------+
+| Label     | Explanation                              |
++===========+==========================================+
+| unseen    | Not read, but previously detected by MUA |
++-----------+------------------------------------------+
+| deleted   | Marked for subsequent deletion           |
++-----------+------------------------------------------+
+| filed     | Copied to another file or mailbox        |
++-----------+------------------------------------------+
+| answered  | Replied to                               |
++-----------+------------------------------------------+
+| forwarded | Forwarded                                |
++-----------+------------------------------------------+
+| edited    | Modified by the user                     |
++-----------+------------------------------------------+
+| resent    | Resent                                   |
++-----------+------------------------------------------+
+
+By default, Rmail displays only visible headers. The :class:`BabylMessage`
+class, though, uses the original headers because they are more complete. Visible
+headers may be accessed explicitly if desired.
+
+:class:`BabylMessage` instances offer the following methods:
+
+
+.. method:: BabylMessage.get_labels()
+
+   Return a list of labels on the message.
+
+
+.. method:: BabylMessage.set_labels(labels)
+
+   Set the list of labels on the message to *labels*.
+
+
+.. method:: BabylMessage.add_label(label)
+
+   Add *label* to the list of labels on the message.
+
+
+.. method:: BabylMessage.remove_label(label)
+
+   Remove *label* from the list of labels on the message.
+
+
+.. method:: BabylMessage.get_visible()
+
+   Return an :class:`Message` instance whose headers are the message's visible
+   headers and whose body is empty.
+
+
+.. method:: BabylMessage.set_visible(visible)
+
+   Set the message's visible headers to be the same as the headers in *message*.
+   Parameter *visible* should be a :class:`Message` instance, an
+   :class:`email.Message.Message` instance, a string, or a file-like object (which
+   should be open in text mode).
+
+
+.. method:: BabylMessage.update_visible()
+
+   When a :class:`BabylMessage` instance's original headers are modified, the
+   visible headers are not automatically modified to correspond. This method
+   updates the visible headers as follows: each visible header with a corresponding
+   original header is set to the value of the original header, each visible header
+   without a corresponding original header is removed, and any of
+   :mailheader:`Date`, :mailheader:`From`, :mailheader:`Reply-To`,
+   :mailheader:`To`, :mailheader:`CC`, and :mailheader:`Subject` that are present
+   in the original headers but not the visible headers are added to the visible
+   headers.
+
+When a :class:`BabylMessage` instance is created based upon a
+:class:`MaildirMessage` instance, the following conversions take place:
+
++-------------------+-------------------------------+
+| Resulting state   | :class:`MaildirMessage` state |
++===================+===============================+
+| "unseen" label    | no S flag                     |
++-------------------+-------------------------------+
+| "deleted" label   | T flag                        |
++-------------------+-------------------------------+
+| "answered" label  | R flag                        |
++-------------------+-------------------------------+
+| "forwarded" label | P flag                        |
++-------------------+-------------------------------+
+
+When a :class:`BabylMessage` instance is created based upon an
+:class:`mboxMessage` or :class:`MMDFMessage` instance, the :mailheader:`Status`
+and :mailheader:`X-Status` headers are omitted and the following conversions
+take place:
+
++------------------+----------------------------------------------+
+| Resulting state  | :class:`mboxMessage` or :class:`MMDFMessage` |
+|                  | state                                        |
++==================+==============================================+
+| "unseen" label   | no R flag                                    |
++------------------+----------------------------------------------+
+| "deleted" label  | D flag                                       |
++------------------+----------------------------------------------+
+| "answered" label | A flag                                       |
++------------------+----------------------------------------------+
+
+When a :class:`BabylMessage` instance is created based upon an
+:class:`MHMessage` instance, the following conversions take place:
+
++------------------+--------------------------+
+| Resulting state  | :class:`MHMessage` state |
++==================+==========================+
+| "unseen" label   | "unseen" sequence        |
++------------------+--------------------------+
+| "answered" label | "replied" sequence       |
++------------------+--------------------------+
+
+
+.. _mailbox-mmdfmessage:
+
+:class:`MMDFMessage`
+^^^^^^^^^^^^^^^^^^^^
+
+
+.. class:: MMDFMessage([message])
+
+   A message with MMDF-specific behaviors. Parameter *message* has the same meaning
+   as with the :class:`Message` constructor.
+
+As with message in an mbox mailbox, MMDF messages are stored with the sender's
+address and the delivery date in an initial line beginning with "From ".
+Likewise, flags that indicate the state of the message are typically stored in
+:mailheader:`Status` and :mailheader:`X-Status` headers.
+
+Conventional flags for MMDF messages are identical to those of mbox message and
+are as follows:
+
++------+----------+--------------------------------+
+| Flag | Meaning  | Explanation                    |
++======+==========+================================+
+| R    | Read     | Read                           |
++------+----------+--------------------------------+
+| O    | Old      | Previously detected by MUA     |
++------+----------+--------------------------------+
+| D    | Deleted  | Marked for subsequent deletion |
++------+----------+--------------------------------+
+| F    | Flagged  | Marked as important            |
++------+----------+--------------------------------+
+| A    | Answered | Replied to                     |
++------+----------+--------------------------------+
+
+The "R" and "O" flags are stored in the :mailheader:`Status` header, and the
+"D", "F", and "A" flags are stored in the :mailheader:`X-Status` header. The
+flags and headers typically appear in the order mentioned.
+
+:class:`MMDFMessage` instances offer the following methods, which are identical
+to those offered by :class:`mboxMessage`:
+
+
+.. method:: MMDFMessage.get_from()
+
+   Return a string representing the "From " line that marks the start of the
+   message in an mbox mailbox. The leading "From " and the trailing newline are
+   excluded.
+
+
+.. method:: MMDFMessage.set_from(from_[, time_=None])
+
+   Set the "From " line to *from_*, which should be specified without a leading
+   "From " or trailing newline. For convenience, *time_* may be specified and will
+   be formatted appropriately and appended to *from_*. If *time_* is specified, it
+   should be a :class:`struct_time` instance, a tuple suitable for passing to
+   :meth:`time.strftime`, or ``True`` (to use :meth:`time.gmtime`).
+
+
+.. method:: MMDFMessage.get_flags()
+
+   Return a string specifying the flags that are currently set. If the message
+   complies with the conventional format, the result is the concatenation in the
+   following order of zero or one occurrence of each of ``'R'``, ``'O'``, ``'D'``,
+   ``'F'``, and ``'A'``.
+
+
+.. method:: MMDFMessage.set_flags(flags)
+
+   Set the flags specified by *flags* and unset all others. Parameter *flags*
+   should be the concatenation in any order of zero or more occurrences of each of
+   ``'R'``, ``'O'``, ``'D'``, ``'F'``, and ``'A'``.
+
+
+.. method:: MMDFMessage.add_flag(flag)
+
+   Set the flag(s) specified by *flag* without changing other flags. To add more
+   than one flag at a time, *flag* may be a string of more than one character.
+
+
+.. method:: MMDFMessage.remove_flag(flag)
+
+   Unset the flag(s) specified by *flag* without changing other flags. To remove
+   more than one flag at a time, *flag* maybe a string of more than one character.
+
+When an :class:`MMDFMessage` instance is created based upon a
+:class:`MaildirMessage` instance, a "From " line is generated based upon the
+:class:`MaildirMessage` instance's delivery date, and the following conversions
+take place:
+
++-----------------+-------------------------------+
+| Resulting state | :class:`MaildirMessage` state |
++=================+===============================+
+| R flag          | S flag                        |
++-----------------+-------------------------------+
+| O flag          | "cur" subdirectory            |
++-----------------+-------------------------------+
+| D flag          | T flag                        |
++-----------------+-------------------------------+
+| F flag          | F flag                        |
++-----------------+-------------------------------+
+| A flag          | R flag                        |
++-----------------+-------------------------------+
+
+When an :class:`MMDFMessage` instance is created based upon an
+:class:`MHMessage` instance, the following conversions take place:
+
++-------------------+--------------------------+
+| Resulting state   | :class:`MHMessage` state |
++===================+==========================+
+| R flag and O flag | no "unseen" sequence     |
++-------------------+--------------------------+
+| O flag            | "unseen" sequence        |
++-------------------+--------------------------+
+| F flag            | "flagged" sequence       |
++-------------------+--------------------------+
+| A flag            | "replied" sequence       |
++-------------------+--------------------------+
+
+When an :class:`MMDFMessage` instance is created based upon a
+:class:`BabylMessage` instance, the following conversions take place:
+
++-------------------+-----------------------------+
+| Resulting state   | :class:`BabylMessage` state |
++===================+=============================+
+| R flag and O flag | no "unseen" label           |
++-------------------+-----------------------------+
+| O flag            | "unseen" label              |
++-------------------+-----------------------------+
+| D flag            | "deleted" label             |
++-------------------+-----------------------------+
+| A flag            | "answered" label            |
++-------------------+-----------------------------+
+
+When an :class:`MMDFMessage` instance is created based upon an
+:class:`mboxMessage` instance, the "From " line is copied and all flags directly
+correspond:
+
++-----------------+----------------------------+
+| Resulting state | :class:`mboxMessage` state |
++=================+============================+
+| R flag          | R flag                     |
++-----------------+----------------------------+
+| O flag          | O flag                     |
++-----------------+----------------------------+
+| D flag          | D flag                     |
++-----------------+----------------------------+
+| F flag          | F flag                     |
++-----------------+----------------------------+
+| A flag          | A flag                     |
++-----------------+----------------------------+
+
+
+Exceptions
+----------
+
+The following exception classes are defined in the :mod:`mailbox` module:
+
+
+.. class:: Error()
+
+   The based class for all other module-specific exceptions.
+
+
+.. class:: NoSuchMailboxError()
+
+   Raised when a mailbox is expected but is not found, such as when instantiating a
+   :class:`Mailbox` subclass with a path that does not exist (and with the *create*
+   parameter set to ``False``), or when opening a folder that does not exist.
+
+
+.. class:: NotEmptyErrorError()
+
+   Raised when a mailbox is not empty but is expected to be, such as when deleting
+   a folder that contains messages.
+
+
+.. class:: ExternalClashError()
+
+   Raised when some mailbox-related condition beyond the control of the program
+   causes it to be unable to proceed, such as when failing to acquire a lock that
+   another program already holds a lock, or when a uniquely-generated file name
+   already exists.
+
+
+.. class:: FormatError()
+
+   Raised when the data in a file cannot be parsed, such as when an :class:`MH`
+   instance attempts to read a corrupted :file:`.mh_sequences` file.
+
+
+.. _mailbox-deprecated:
+
+Deprecated classes and methods
+------------------------------
+
+Older versions of the :mod:`mailbox` module do not support modification of
+mailboxes, such as adding or removing message, and do not provide classes to
+represent format-specific message properties. For backward compatibility, the
+older mailbox classes are still available, but the newer classes should be used
+in preference to them.
+
+Older mailbox objects support only iteration and provide a single public method:
+
+
+.. method:: oldmailbox.next()
+
+   Return the next message in the mailbox, created with the optional *factory*
+   argument passed into the mailbox object's constructor. By default this is an
+   :class:`rfc822.Message` object (see the :mod:`rfc822` module).  Depending on the
+   mailbox implementation the *fp* attribute of this object may be a true file
+   object or a class instance simulating a file object, taking care of things like
+   message boundaries if multiple mail messages are contained in a single file,
+   etc.  If no more messages are available, this method returns ``None``.
+
+Most of the older mailbox classes have names that differ from the current
+mailbox class names, except for :class:`Maildir`. For this reason, the new
+:class:`Maildir` class defines a :meth:`next` method and its constructor differs
+slightly from those of the other new mailbox classes.
+
+The older mailbox classes whose names are not the same as their newer
+counterparts are as follows:
+
+
+.. class:: UnixMailbox(fp[, factory])
+
+   Access to a classic Unix-style mailbox, where all messages are contained in a
+   single file and separated by ``From`` (a.k.a. ``From_``) lines.  The file object
+   *fp* points to the mailbox file.  The optional *factory* parameter is a callable
+   that should create new message objects.  *factory* is called with one argument,
+   *fp* by the :meth:`next` method of the mailbox object.  The default is the
+   :class:`rfc822.Message` class (see the :mod:`rfc822` module -- and the note
+   below).
+
+   .. note::
+
+      For reasons of this module's internal implementation, you will probably want to
+      open the *fp* object in binary mode.  This is especially important on Windows.
+
+   For maximum portability, messages in a Unix-style mailbox are separated by any
+   line that begins exactly with the string ``'From '`` (note the trailing space)
+   if preceded by exactly two newlines. Because of the wide-range of variations in
+   practice, nothing else on the ``From_`` line should be considered.  However, the
+   current implementation doesn't check for the leading two newlines.  This is
+   usually fine for most applications.
+
+   The :class:`UnixMailbox` class implements a more strict version of ``From_``
+   line checking, using a regular expression that usually correctly matched
+   ``From_`` delimiters.  It considers delimiter line to be separated by ``From
+   name time`` lines.  For maximum portability, use the
+   :class:`PortableUnixMailbox` class instead.  This class is identical to
+   :class:`UnixMailbox` except that individual messages are separated by only
+   ``From`` lines.
+
+   For more information, see `Configuring Netscape Mail on Unix: Why the
+   Content-Length Format is Bad
+   `_.
+
+
+.. class:: PortableUnixMailbox(fp[, factory])
+
+   A less-strict version of :class:`UnixMailbox`, which considers only the ``From``
+   at the beginning of the line separating messages.  The "*name* *time*" portion
+   of the From line is ignored, to protect against some variations that are
+   observed in practice.  This works since lines in the message which begin with
+   ``'From '`` are quoted by mail handling software at delivery-time.
+
+
+.. class:: MmdfMailbox(fp[, factory])
+
+   Access an MMDF-style mailbox, where all messages are contained in a single file
+   and separated by lines consisting of 4 control-A characters.  The file object
+   *fp* points to the mailbox file. Optional *factory* is as with the
+   :class:`UnixMailbox` class.
+
+
+.. class:: MHMailbox(dirname[, factory])
+
+   Access an MH mailbox, a directory with each message in a separate file with a
+   numeric name. The name of the mailbox directory is passed in *dirname*.
+   *factory* is as with the :class:`UnixMailbox` class.
+
+
+.. class:: BabylMailbox(fp[, factory])
+
+   Access a Babyl mailbox, which is similar to an MMDF mailbox.  In Babyl format,
+   each message has two sets of headers, the *original* headers and the *visible*
+   headers.  The original headers appear before a line containing only ``'*** EOOH
+   ***'`` (End-Of-Original-Headers) and the visible headers appear after the
+   ``EOOH`` line.  Babyl-compliant mail readers will show you only the visible
+   headers, and :class:`BabylMailbox` objects will return messages containing only
+   the visible headers.  You'll have to do your own parsing of the mailbox file to
+   get at the original headers.  Mail messages start with the EOOH line and end
+   with a line containing only ``'\037\014'``.  *factory* is as with the
+   :class:`UnixMailbox` class.
+
+If you wish to use the older mailbox classes with the :mod:`email` module rather
+than the deprecated :mod:`rfc822` module, you can do so as follows::
+
+   import email
+   import email.Errors
+   import mailbox
+
+   def msgfactory(fp):
+       try:
+           return email.message_from_file(fp)
+       except email.Errors.MessageParseError:
+           # Don't return None since that will
+           # stop the mailbox iterator
+           return ''
+
+   mbox = mailbox.UnixMailbox(fp, msgfactory)
+
+Alternatively, if you know your mailbox contains only well-formed MIME messages,
+you can simplify this to::
+
+   import email
+   import mailbox
+
+   mbox = mailbox.UnixMailbox(fp, email.message_from_file)
+
+
+.. _mailbox-examples:
+
+Examples
+--------
+
+A simple example of printing the subjects of all messages in a mailbox that seem
+interesting::
+
+   import mailbox
+   for message in mailbox.mbox('~/mbox'):
+       subject = message['subject']       # Could possibly be None.
+       if subject and 'python' in subject.lower():
+           print subject
+
+To copy all mail from a Babyl mailbox to an MH mailbox, converting all of the
+format-specific information that can be converted::
+
+   import mailbox
+   destination = mailbox.MH('~/Mail')
+   destination.lock()
+   for message in mailbox.Babyl('~/RMAIL'):
+       destination.add(MHMessage(message))
+   destination.flush()
+   destination.unlock()
+
+This example sorts mail from several mailing lists into different mailboxes,
+being careful to avoid mail corruption due to concurrent modification by other
+programs, mail loss due to interruption of the program, or premature termination
+due to malformed messages in the mailbox::
+
+   import mailbox
+   import email.Errors
+
+   list_names = ('python-list', 'python-dev', 'python-bugs')
+
+   boxes = dict((name, mailbox.mbox('~/email/%s' % name)) for name in list_names)
+   inbox = mailbox.Maildir('~/Maildir', factory=None)
+
+   for key in inbox.iterkeys():
+       try:
+           message = inbox[key]
+       except email.Errors.MessageParseError:
+           continue                # The message is malformed. Just leave it.
+
+       for name in list_names:
+           list_id = message['list-id']
+           if list_id and name in list_id:
+               # Get mailbox to use
+               box = boxes[name]
+
+               # Write copy to disk before removing original.
+               # If there's a crash, you might duplicate a message, but
+               # that's better than losing a message completely.
+               box.lock()
+               box.add(message)
+               box.flush()         
+               box.unlock()
+
+               # Remove original message
+               inbox.lock()
+               inbox.discard(key)
+               inbox.flush()
+               inbox.unlock()
+               break               # Found destination, so stop looking.
+
+   for box in boxes.itervalues():
+       box.close()
+
diff --git a/Doc/library/mailcap.rst b/Doc/library/mailcap.rst
new file mode 100644
index 0000000..8dcb1ec
--- /dev/null
+++ b/Doc/library/mailcap.rst
@@ -0,0 +1,74 @@
+:mod:`mailcap` --- Mailcap file handling
+========================================
+
+.. module:: mailcap
+   :synopsis: Mailcap file handling.
+
+
+
+Mailcap files are used to configure how MIME-aware applications such as mail
+readers and Web browsers react to files with different MIME types. (The name
+"mailcap" is derived from the phrase "mail capability".)  For example, a mailcap
+file might contain a line like ``video/mpeg; xmpeg %s``.  Then, if the user
+encounters an email message or Web document with the MIME type
+:mimetype:`video/mpeg`, ``%s`` will be replaced by a filename (usually one
+belonging to a temporary file) and the :program:`xmpeg` program can be
+automatically started to view the file.
+
+The mailcap format is documented in :rfc:`1524`, "A User Agent Configuration
+Mechanism For Multimedia Mail Format Information," but is not an Internet
+standard.  However, mailcap files are supported on most Unix systems.
+
+
+.. function:: findmatch(caps, MIMEtype[, key[, filename[, plist]]])
+
+   Return a 2-tuple; the first element is a string containing the command line to
+   be executed (which can be passed to :func:`os.system`), and the second element
+   is the mailcap entry for a given MIME type.  If no matching MIME type can be
+   found, ``(None, None)`` is returned.
+
+   *key* is the name of the field desired, which represents the type of activity to
+   be performed; the default value is 'view', since in the  most common case you
+   simply want to view the body of the MIME-typed data.  Other possible values
+   might be 'compose' and 'edit', if you wanted to create a new body of the given
+   MIME type or alter the existing body data.  See :rfc:`1524` for a complete list
+   of these fields.
+
+   *filename* is the filename to be substituted for ``%s`` in the command line; the
+   default value is ``'/dev/null'`` which is almost certainly not what you want, so
+   usually you'll override it by specifying a filename.
+
+   *plist* can be a list containing named parameters; the default value is simply
+   an empty list.  Each entry in the list must be a string containing the parameter
+   name, an equals sign (``'='``), and the parameter's value.  Mailcap entries can
+   contain  named parameters like ``%{foo}``, which will be replaced by the value
+   of the parameter named 'foo'.  For example, if the command line ``showpartial
+   %{id} %{number} %{total}`` was in a mailcap file, and *plist* was set to
+   ``['id=1', 'number=2', 'total=3']``, the resulting command line would be
+   ``'showpartial 1 2 3'``.
+
+   In a mailcap file, the "test" field can optionally be specified to test some
+   external condition (such as the machine architecture, or the window system in
+   use) to determine whether or not the mailcap line applies.  :func:`findmatch`
+   will automatically check such conditions and skip the entry if the check fails.
+
+
+.. function:: getcaps()
+
+   Returns a dictionary mapping MIME types to a list of mailcap file entries. This
+   dictionary must be passed to the :func:`findmatch` function.  An entry is stored
+   as a list of dictionaries, but it shouldn't be necessary to know the details of
+   this representation.
+
+   The information is derived from all of the mailcap files found on the system.
+   Settings in the user's mailcap file :file:`$HOME/.mailcap` will override
+   settings in the system mailcap files :file:`/etc/mailcap`,
+   :file:`/usr/etc/mailcap`, and :file:`/usr/local/etc/mailcap`.
+
+An example usage::
+
+   >>> import mailcap
+   >>> d=mailcap.getcaps()
+   >>> mailcap.findmatch(d, 'video/mpeg', filename='/tmp/tmp1223')
+   ('xmpeg /tmp/tmp1223', {'view': 'xmpeg %s'})
+
diff --git a/Doc/library/markup.rst b/Doc/library/markup.rst
new file mode 100644
index 0000000..dd0dd8f
--- /dev/null
+++ b/Doc/library/markup.rst
@@ -0,0 +1,44 @@
+
+.. _markup:
+
+**********************************
+Structured Markup Processing Tools
+**********************************
+
+Python supports a variety of modules to work with various forms of structured
+data markup.  This includes modules to work with the Standard Generalized Markup
+Language (SGML) and the Hypertext Markup Language (HTML), and several interfaces
+for working with the Extensible Markup Language (XML).
+
+It is important to note that modules in the :mod:`xml` package require that
+there be at least one SAX-compliant XML parser available. Starting with Python
+2.3, the Expat parser is included with Python, so the :mod:`xml.parsers.expat`
+module will always be available. You may still want to be aware of the `PyXML
+add-on package `_; that package provides an
+extended set of XML libraries for Python.
+
+The documentation for the :mod:`xml.dom` and :mod:`xml.sax` packages are the
+definition of the Python bindings for the DOM and SAX interfaces.
+
+
+.. toctree::
+
+   htmlparser.rst
+   sgmllib.rst
+   htmllib.rst
+   pyexpat.rst
+   xml.dom.rst
+   xml.dom.minidom.rst
+   xml.dom.pulldom.rst
+   xml.sax.rst
+   xml.sax.handler.rst
+   xml.sax.utils.rst
+   xml.sax.reader.rst
+   xml.etree.elementtree.rst
+
+.. seealso::
+
+   `Python/XML Libraries `_
+      Home page for the PyXML package, containing an extension of :mod:`xml` package
+      bundled with Python.
+
diff --git a/Doc/library/marshal.rst b/Doc/library/marshal.rst
new file mode 100644
index 0000000..010ebc3
--- /dev/null
+++ b/Doc/library/marshal.rst
@@ -0,0 +1,127 @@
+
+:mod:`marshal` --- Internal Python object serialization
+=======================================================
+
+.. module:: marshal
+   :synopsis: Convert Python objects to streams of bytes and back (with different
+              constraints).
+
+
+This module contains functions that can read and write Python values in a binary
+format.  The format is specific to Python, but independent of machine
+architecture issues (e.g., you can write a Python value to a file on a PC,
+transport the file to a Sun, and read it back there).  Details of the format are
+undocumented on purpose; it may change between Python versions (although it
+rarely does). [#]_
+
+.. index::
+   module: pickle
+   module: shelve
+   object: code
+
+This is not a general "persistence" module.  For general persistence and
+transfer of Python objects through RPC calls, see the modules :mod:`pickle` and
+:mod:`shelve`.  The :mod:`marshal` module exists mainly to support reading and
+writing the "pseudo-compiled" code for Python modules of :file:`.pyc` files.
+Therefore, the Python maintainers reserve the right to modify the marshal format
+in backward incompatible ways should the need arise.  If you're serializing and
+de-serializing Python objects, use the :mod:`pickle` module instead.
+
+.. warning::
+
+   The :mod:`marshal` module is not intended to be secure against erroneous or
+   maliciously constructed data.  Never unmarshal data received from an
+   untrusted or unauthenticated source.
+
+Not all Python object types are supported; in general, only objects whose value
+is independent from a particular invocation of Python can be written and read by
+this module.  The following types are supported: ``None``, integers, long
+integers, floating point numbers, strings, Unicode objects, tuples, lists,
+dictionaries, and code objects, where it should be understood that tuples, lists
+and dictionaries are only supported as long as the values contained therein are
+themselves supported; and recursive lists and dictionaries should not be written
+(they will cause infinite loops).
+
+**Caveat:** On machines where C's ``long int`` type has more than 32 bits (such
+as the DEC Alpha), it is possible to create plain Python integers that are
+longer than 32 bits. If such an integer is marshaled and read back in on a
+machine where C's ``long int`` type has only 32 bits, a Python long integer
+object is returned instead.  While of a different type, the numeric value is the
+same.  (This behavior is new in Python 2.2.  In earlier versions, all but the
+least-significant 32 bits of the value were lost, and a warning message was
+printed.)
+
+There are functions that read/write files as well as functions operating on
+strings.
+
+The module defines these functions:
+
+
+.. function:: dump(value, file[, version])
+
+   Write the value on the open file.  The value must be a supported type.  The
+   file must be an open file object such as ``sys.stdout`` or returned by
+   :func:`open` or :func:`os.popen`.  It must be opened in binary mode (``'wb'``
+   or ``'w+b'``).
+
+   If the value has (or contains an object that has) an unsupported type, a
+   :exc:`ValueError` exception is raised --- but garbage data will also be written
+   to the file.  The object will not be properly read back by :func:`load`.
+
+   .. versionadded:: 2.4
+      The *version* argument indicates the data format that ``dump`` should use
+      (see below).
+
+
+.. function:: load(file)
+
+   Read one value from the open file and return it.  If no valid value is read
+   (e.g. because the data has a different Python version's incompatible marshal
+   format), raise :exc:`EOFError`, :exc:`ValueError` or :exc:`TypeError`.  The
+   file must be an open file object opened in binary mode (``'rb'`` or
+   ``'r+b'``).
+
+   .. warning::
+
+      If an object containing an unsupported type was marshalled with :func:`dump`,
+      :func:`load` will substitute ``None`` for the unmarshallable type.
+
+
+.. function:: dumps(value[, version])
+
+   Return the string that would be written to a file by ``dump(value, file)``.  The
+   value must be a supported type.  Raise a :exc:`ValueError` exception if value
+   has (or contains an object that has) an unsupported type.
+
+   .. versionadded:: 2.4
+      The *version* argument indicates the data format that ``dumps`` should use
+      (see below).
+
+
+.. function:: loads(string)
+
+   Convert the string to a value.  If no valid value is found, raise
+   :exc:`EOFError`, :exc:`ValueError` or :exc:`TypeError`.  Extra characters in the
+   string are ignored.
+
+
+In addition, the following constants are defined:
+
+.. data:: version
+
+   Indicates the format that the module uses. Version 0 is the historical format,
+   version 1 (added in Python 2.4) shares interned strings and version 2 (added in
+   Python 2.5) uses a binary format for floating point numbers. The current version
+   is 2.
+
+   .. versionadded:: 2.4
+
+
+.. rubric:: Footnotes
+
+.. [#] The name of this module stems from a bit of terminology used by the designers of
+   Modula-3 (amongst others), who use the term "marshalling" for shipping of data
+   around in a self-contained form. Strictly speaking, "to marshal" means to
+   convert some data from internal to external form (in an RPC buffer for instance)
+   and "unmarshalling" for the reverse process.
+
diff --git a/Doc/library/math.rst b/Doc/library/math.rst
new file mode 100644
index 0000000..17c75d3
--- /dev/null
+++ b/Doc/library/math.rst
@@ -0,0 +1,227 @@
+
+:mod:`math` --- Mathematical functions
+======================================
+
+.. module:: math
+   :synopsis: Mathematical functions (sin() etc.).
+
+
+This module is always available.  It provides access to the mathematical
+functions defined by the C standard.
+
+These functions cannot be used with complex numbers; use the functions of the
+same name from the :mod:`cmath` module if you require support for complex
+numbers.  The distinction between functions which support complex numbers and
+those which don't is made since most users do not want to learn quite as much
+mathematics as required to understand complex numbers.  Receiving an exception
+instead of a complex result allows earlier detection of the unexpected complex
+number used as a parameter, so that the programmer can determine how and why it
+was generated in the first place.
+
+The following functions are provided by this module.  Except when explicitly
+noted otherwise, all return values are floats.
+
+Number-theoretic and representation functions:
+
+
+.. function:: ceil(x)
+
+   Return the ceiling of *x* as a float, the smallest integer value greater than or
+   equal to *x*.
+
+
+.. function:: fabs(x)
+
+   Return the absolute value of *x*.
+
+
+.. function:: floor(x)
+
+   Return the floor of *x* as a float, the largest integer value less than or equal
+   to *x*.
+
+
+.. function:: fmod(x, y)
+
+   Return ``fmod(x, y)``, as defined by the platform C library. Note that the
+   Python expression ``x % y`` may not return the same result.  The intent of the C
+   standard is that ``fmod(x, y)`` be exactly (mathematically; to infinite
+   precision) equal to ``x - n*y`` for some integer *n* such that the result has
+   the same sign as *x* and magnitude less than ``abs(y)``.  Python's ``x % y``
+   returns a result with the sign of *y* instead, and may not be exactly computable
+   for float arguments. For example, ``fmod(-1e-100, 1e100)`` is ``-1e-100``, but
+   the result of Python's ``-1e-100 % 1e100`` is ``1e100-1e-100``, which cannot be
+   represented exactly as a float, and rounds to the surprising ``1e100``.  For
+   this reason, function :func:`fmod` is generally preferred when working with
+   floats, while Python's ``x % y`` is preferred when working with integers.
+
+
+.. function:: frexp(x)
+
+   Return the mantissa and exponent of *x* as the pair ``(m, e)``.  *m* is a float
+   and *e* is an integer such that ``x == m * 2**e`` exactly. If *x* is zero,
+   returns ``(0.0, 0)``, otherwise ``0.5 <= abs(m) < 1``.  This is used to "pick
+   apart" the internal representation of a float in a portable way.
+
+
+.. function:: ldexp(x, i)
+
+   Return ``x * (2**i)``.  This is essentially the inverse of function
+   :func:`frexp`.
+
+
+.. function:: modf(x)
+
+   Return the fractional and integer parts of *x*.  Both results carry the sign of
+   *x*, and both are floats.
+
+Note that :func:`frexp` and :func:`modf` have a different call/return pattern
+than their C equivalents: they take a single argument and return a pair of
+values, rather than returning their second return value through an 'output
+parameter' (there is no such thing in Python).
+
+For the :func:`ceil`, :func:`floor`, and :func:`modf` functions, note that *all*
+floating-point numbers of sufficiently large magnitude are exact integers.
+Python floats typically carry no more than 53 bits of precision (the same as the
+platform C double type), in which case any float *x* with ``abs(x) >= 2**52``
+necessarily has no fractional bits.
+
+Power and logarithmic functions:
+
+
+.. function:: exp(x)
+
+   Return ``e**x``.
+
+
+.. function:: log(x[, base])
+
+   Return the logarithm of *x* to the given *base*. If the *base* is not specified,
+   return the natural logarithm of *x* (that is, the logarithm to base *e*).
+
+   .. versionchanged:: 2.3
+      *base* argument added.
+
+
+.. function:: log10(x)
+
+   Return the base-10 logarithm of *x*.
+
+
+.. function:: pow(x, y)
+
+   Return ``x**y``.
+
+
+.. function:: sqrt(x)
+
+   Return the square root of *x*.
+
+Trigonometric functions:
+
+
+.. function:: acos(x)
+
+   Return the arc cosine of *x*, in radians.
+
+
+.. function:: asin(x)
+
+   Return the arc sine of *x*, in radians.
+
+
+.. function:: atan(x)
+
+   Return the arc tangent of *x*, in radians.
+
+
+.. function:: atan2(y, x)
+
+   Return ``atan(y / x)``, in radians. The result is between ``-pi`` and ``pi``.
+   The vector in the plane from the origin to point ``(x, y)`` makes this angle
+   with the positive X axis. The point of :func:`atan2` is that the signs of both
+   inputs are known to it, so it can compute the correct quadrant for the angle.
+   For example, ``atan(1``) and ``atan2(1, 1)`` are both ``pi/4``, but ``atan2(-1,
+   -1)`` is ``-3*pi/4``.
+
+
+.. function:: cos(x)
+
+   Return the cosine of *x* radians.
+
+
+.. function:: hypot(x, y)
+
+   Return the Euclidean norm, ``sqrt(x*x + y*y)``. This is the length of the vector
+   from the origin to point ``(x, y)``.
+
+
+.. function:: sin(x)
+
+   Return the sine of *x* radians.
+
+
+.. function:: tan(x)
+
+   Return the tangent of *x* radians.
+
+Angular conversion:
+
+
+.. function:: degrees(x)
+
+   Converts angle *x* from radians to degrees.
+
+
+.. function:: radians(x)
+
+   Converts angle *x* from degrees to radians.
+
+Hyperbolic functions:
+
+
+.. function:: cosh(x)
+
+   Return the hyperbolic cosine of *x*.
+
+
+.. function:: sinh(x)
+
+   Return the hyperbolic sine of *x*.
+
+
+.. function:: tanh(x)
+
+   Return the hyperbolic tangent of *x*.
+
+The module also defines two mathematical constants:
+
+
+.. data:: pi
+
+   The mathematical constant *pi*.
+
+
+.. data:: e
+
+   The mathematical constant *e*.
+
+.. note::
+
+   The :mod:`math` module consists mostly of thin wrappers around the platform C
+   math library functions.  Behavior in exceptional cases is loosely specified
+   by the C standards, and Python inherits much of its math-function
+   error-reporting behavior from the platform C implementation.  As a result,
+   the specific exceptions raised in error cases (and even whether some
+   arguments are considered to be exceptional at all) are not defined in any
+   useful cross-platform or cross-release way.  For example, whether
+   ``math.log(0)`` returns ``-Inf`` or raises :exc:`ValueError` or
+   :exc:`OverflowError` isn't defined, and in cases where ``math.log(0)`` raises
+   :exc:`OverflowError`, ``math.log(0L)`` may raise :exc:`ValueError` instead.
+
+
+.. seealso::
+
+   Module :mod:`cmath`
+      Complex number versions of many of these functions.
+
diff --git a/Doc/library/mhlib.rst b/Doc/library/mhlib.rst
new file mode 100644
index 0000000..15d2b05
--- /dev/null
+++ b/Doc/library/mhlib.rst
@@ -0,0 +1,205 @@
+
+:mod:`mhlib` --- Access to MH mailboxes
+=======================================
+
+.. module:: mhlib
+   :synopsis: Manipulate MH mailboxes from Python.
+
+
+.. % LaTeX'ized from the comments in the module by Skip Montanaro
+.. % .
+
+The :mod:`mhlib` module provides a Python interface to MH folders and their
+contents.
+
+The module contains three basic classes, :class:`MH`, which represents a
+particular collection of folders, :class:`Folder`, which represents a single
+folder, and :class:`Message`, which represents a single message.
+
+
+.. class:: MH([path[, profile]])
+
+   :class:`MH` represents a collection of MH folders.
+
+
+.. class:: Folder(mh, name)
+
+   The :class:`Folder` class represents a single folder and its messages.
+
+
+.. class:: Message(folder, number[, name])
+
+   :class:`Message` objects represent individual messages in a folder.  The Message
+   class is derived from :class:`mimetools.Message`.
+
+
+.. _mh-objects:
+
+MH Objects
+----------
+
+:class:`MH` instances have the following methods:
+
+
+.. method:: MH.error(format[, ...])
+
+   Print an error message -- can be overridden.
+
+
+.. method:: MH.getprofile(key)
+
+   Return a profile entry (``None`` if not set).
+
+
+.. method:: MH.getpath()
+
+   Return the mailbox pathname.
+
+
+.. method:: MH.getcontext()
+
+   Return the current folder name.
+
+
+.. method:: MH.setcontext(name)
+
+   Set the current folder name.
+
+
+.. method:: MH.listfolders()
+
+   Return a list of top-level folders.
+
+
+.. method:: MH.listallfolders()
+
+   Return a list of all folders.
+
+
+.. method:: MH.listsubfolders(name)
+
+   Return a list of direct subfolders of the given folder.
+
+
+.. method:: MH.listallsubfolders(name)
+
+   Return a list of all subfolders of the given folder.
+
+
+.. method:: MH.makefolder(name)
+
+   Create a new folder.
+
+
+.. method:: MH.deletefolder(name)
+
+   Delete a folder -- must have no subfolders.
+
+
+.. method:: MH.openfolder(name)
+
+   Return a new open folder object.
+
+
+.. _mh-folder-objects:
+
+Folder Objects
+--------------
+
+:class:`Folder` instances represent open folders and have the following methods:
+
+
+.. method:: Folder.error(format[, ...])
+
+   Print an error message -- can be overridden.
+
+
+.. method:: Folder.getfullname()
+
+   Return the folder's full pathname.
+
+
+.. method:: Folder.getsequencesfilename()
+
+   Return the full pathname of the folder's sequences file.
+
+
+.. method:: Folder.getmessagefilename(n)
+
+   Return the full pathname of message *n* of the folder.
+
+
+.. method:: Folder.listmessages()
+
+   Return a list of messages in the folder (as numbers).
+
+
+.. method:: Folder.getcurrent()
+
+   Return the current message number.
+
+
+.. method:: Folder.setcurrent(n)
+
+   Set the current message number to *n*.
+
+
+.. method:: Folder.parsesequence(seq)
+
+   Parse msgs syntax into list of messages.
+
+
+.. method:: Folder.getlast()
+
+   Get last message, or ``0`` if no messages are in the folder.
+
+
+.. method:: Folder.setlast(n)
+
+   Set last message (internal use only).
+
+
+.. method:: Folder.getsequences()
+
+   Return dictionary of sequences in folder.  The sequence names are used  as keys,
+   and the values are the lists of message numbers in the sequences.
+
+
+.. method:: Folder.putsequences(dict)
+
+   Return dictionary of sequences in folder name: list.
+
+
+.. method:: Folder.removemessages(list)
+
+   Remove messages in list from folder.
+
+
+.. method:: Folder.refilemessages(list, tofolder)
+
+   Move messages in list to other folder.
+
+
+.. method:: Folder.movemessage(n, tofolder, ton)
+
+   Move one message to a given destination in another folder.
+
+
+.. method:: Folder.copymessage(n, tofolder, ton)
+
+   Copy one message to a given destination in another folder.
+
+
+.. _mh-message-objects:
+
+Message Objects
+---------------
+
+The :class:`Message` class adds one method to those of
+:class:`mimetools.Message`:
+
+
+.. method:: Message.openmessage(n)
+
+   Return a new open message object (costs a file descriptor).
+
diff --git a/Doc/library/mimetools.rst b/Doc/library/mimetools.rst
new file mode 100644
index 0000000..603bec6
--- /dev/null
+++ b/Doc/library/mimetools.rst
@@ -0,0 +1,130 @@
+
+:mod:`mimetools` --- Tools for parsing MIME messages
+====================================================
+
+.. module:: mimetools
+   :synopsis: Tools for parsing MIME-style message bodies.
+
+
+.. deprecated:: 2.3
+   The :mod:`email` package should be used in preference to the :mod:`mimetools`
+   module.  This module is present only to maintain backward compatibility.
+
+.. index:: module: rfc822
+
+This module defines a subclass of the :mod:`rfc822` module's :class:`Message`
+class and a number of utility functions that are useful for the manipulation for
+MIME multipart or encoded message.
+
+It defines the following items:
+
+
+.. class:: Message(fp[, seekable])
+
+   Return a new instance of the :class:`Message` class.  This is a subclass of the
+   :class:`rfc822.Message` class, with some additional methods (see below).  The
+   *seekable* argument has the same meaning as for :class:`rfc822.Message`.
+
+
+.. function:: choose_boundary()
+
+   Return a unique string that has a high likelihood of being usable as a part
+   boundary.  The string has the form ``'hostipaddr.uid.pid.timestamp.random'``.
+
+
+.. function:: decode(input, output, encoding)
+
+   Read data encoded using the allowed MIME *encoding* from open file object
+   *input* and write the decoded data to open file object *output*.  Valid values
+   for *encoding* include ``'base64'``, ``'quoted-printable'``, ``'uuencode'``,
+   ``'x-uuencode'``, ``'uue'``, ``'x-uue'``, ``'7bit'``, and  ``'8bit'``.  Decoding
+   messages encoded in ``'7bit'`` or ``'8bit'`` has no effect.  The input is simply
+   copied to the output.
+
+
+.. function:: encode(input, output, encoding)
+
+   Read data from open file object *input* and write it encoded using the allowed
+   MIME *encoding* to open file object *output*. Valid values for *encoding* are
+   the same as for :meth:`decode`.
+
+
+.. function:: copyliteral(input, output)
+
+   Read lines from open file *input* until EOF and write them to open file
+   *output*.
+
+
+.. function:: copybinary(input, output)
+
+   Read blocks until EOF from open file *input* and write them to open file
+   *output*.  The block size is currently fixed at 8192.
+
+
+.. seealso::
+
+   Module :mod:`email`
+      Comprehensive email handling package; supersedes the :mod:`mimetools` module.
+
+   Module :mod:`rfc822`
+      Provides the base class for :class:`mimetools.Message`.
+
+   Module :mod:`multifile`
+      Support for reading files which contain distinct parts, such as MIME data.
+
+   http://www.cs.uu.nl/wais/html/na-dir/mail/mime-faq/.html
+      The MIME Frequently Asked Questions document.  For an overview of MIME, see the
+      answer to question 1.1 in Part 1 of this document.
+
+
+.. _mimetools-message-objects:
+
+Additional Methods of Message Objects
+-------------------------------------
+
+The :class:`Message` class defines the following methods in addition to the
+:class:`rfc822.Message` methods:
+
+
+.. method:: Message.getplist()
+
+   Return the parameter list of the :mailheader:`Content-Type` header. This is a
+   list of strings.  For parameters of the form ``key=value``, *key* is converted
+   to lower case but *value* is not.  For example, if the message contains the
+   header ``Content-type: text/html; spam=1; Spam=2; Spam`` then :meth:`getplist`
+   will return the Python list ``['spam=1', 'spam=2', 'Spam']``.
+
+
+.. method:: Message.getparam(name)
+
+   Return the *value* of the first parameter (as returned by :meth:`getplist`) of
+   the form ``name=value`` for the given *name*.  If *value* is surrounded by
+   quotes of the form '``<``...\ ``>``' or '``"``...\ ``"``', these are removed.
+
+
+.. method:: Message.getencoding()
+
+   Return the encoding specified in the :mailheader:`Content-Transfer-Encoding`
+   message header.  If no such header exists, return ``'7bit'``.  The encoding is
+   converted to lower case.
+
+
+.. method:: Message.gettype()
+
+   Return the message type (of the form ``type/subtype``) as specified in the
+   :mailheader:`Content-Type` header.  If no such header exists, return
+   ``'text/plain'``.  The type is converted to lower case.
+
+
+.. method:: Message.getmaintype()
+
+   Return the main type as specified in the :mailheader:`Content-Type` header.  If
+   no such header exists, return ``'text'``.  The main type is converted to lower
+   case.
+
+
+.. method:: Message.getsubtype()
+
+   Return the subtype as specified in the :mailheader:`Content-Type` header.  If no
+   such header exists, return ``'plain'``.  The subtype is converted to lower case.
+
diff --git a/Doc/library/mimetypes.rst b/Doc/library/mimetypes.rst
new file mode 100644
index 0000000..fd5e12d
--- /dev/null
+++ b/Doc/library/mimetypes.rst
@@ -0,0 +1,232 @@
+
+:mod:`mimetypes` --- Map filenames to MIME types
+================================================
+
+.. module:: mimetypes
+   :synopsis: Mapping of filename extensions to MIME types.
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+.. index:: pair: MIME; content type
+
+The :mod:`mimetypes` module converts between a filename or URL and the MIME type
+associated with the filename extension.  Conversions are provided from filename
+to MIME type and from MIME type to filename extension; encodings are not
+supported for the latter conversion.
+
+The module provides one class and a number of convenience functions. The
+functions are the normal interface to this module, but some applications may be
+interested in the class as well.
+
+The functions described below provide the primary interface for this module.  If
+the module has not been initialized, they will call :func:`init` if they rely on
+the information :func:`init` sets up.
+
+
+.. function:: guess_type(filename[, strict])
+
+   .. index:: pair: MIME; headers
+
+   Guess the type of a file based on its filename or URL, given by *filename*.  The
+   return value is a tuple ``(type, encoding)`` where *type* is ``None`` if the
+   type can't be guessed (missing or unknown suffix) or a string of the form
+   ``'type/subtype'``, usable for a MIME :mailheader:`content-type` header.
+
+   *encoding* is ``None`` for no encoding or the name of the program used to encode
+   (e.g. :program:`compress` or :program:`gzip`). The encoding is suitable for use
+   as a :mailheader:`Content-Encoding` header, *not* as a
+   :mailheader:`Content-Transfer-Encoding` header. The mappings are table driven.
+   Encoding suffixes are case sensitive; type suffixes are first tried case
+   sensitively, then case insensitively.
+
+   Optional *strict* is a flag specifying whether the list of known MIME types
+   is limited to only the official types `registered with IANA
+   `_ are recognized.
+   When *strict* is true (the default), only the IANA types are supported; when
+   *strict* is false, some additional non-standard but commonly used MIME types
+   are also recognized.
+
+
+.. function:: guess_all_extensions(type[, strict])
+
+   Guess the extensions for a file based on its MIME type, given by *type*. The
+   return value is a list of strings giving all possible filename extensions,
+   including the leading dot (``'.'``).  The extensions are not guaranteed to have
+   been associated with any particular data stream, but would be mapped to the MIME
+   type *type* by :func:`guess_type`.
+
+   Optional *strict* has the same meaning as with the :func:`guess_type` function.
+
+
+.. function:: guess_extension(type[, strict])
+
+   Guess the extension for a file based on its MIME type, given by *type*. The
+   return value is a string giving a filename extension, including the leading dot
+   (``'.'``).  The extension is not guaranteed to have been associated with any
+   particular data stream, but would be mapped to the  MIME type *type* by
+   :func:`guess_type`.  If no extension can be guessed for *type*, ``None`` is
+   returned.
+
+   Optional *strict* has the same meaning as with the :func:`guess_type` function.
+
+Some additional functions and data items are available for controlling the
+behavior of the module.
+
+
+.. function:: init([files])
+
+   Initialize the internal data structures.  If given, *files* must be a sequence
+   of file names which should be used to augment the default type map.  If omitted,
+   the file names to use are taken from :const:`knownfiles`.  Each file named in
+   *files* or :const:`knownfiles` takes precedence over those named before it.
+   Calling :func:`init` repeatedly is allowed.
+
+
+.. function:: read_mime_types(filename)
+
+   Load the type map given in the file *filename*, if it exists.  The  type map is
+   returned as a dictionary mapping filename extensions, including the leading dot
+   (``'.'``), to strings of the form ``'type/subtype'``.  If the file *filename*
+   does not exist or cannot be read, ``None`` is returned.
+
+
+.. function:: add_type(type, ext[, strict])
+
+   Add a mapping from the mimetype *type* to the extension *ext*. When the
+   extension is already known, the new type will replace the old one. When the type
+   is already known the extension will be added to the list of known extensions.
+
+   When *strict* is the mapping will added to the official MIME types, otherwise to
+   the non-standard ones.
+
+
+.. data:: inited
+
+   Flag indicating whether or not the global data structures have been initialized.
+   This is set to true by :func:`init`.
+
+
+.. data:: knownfiles
+
+   .. index:: single: file; mime.types
+
+   List of type map file names commonly installed.  These files are typically named
+   :file:`mime.types` and are installed in different locations by different
+   packages.
+
+
+.. data:: suffix_map
+
+   Dictionary mapping suffixes to suffixes.  This is used to allow recognition of
+   encoded files for which the encoding and the type are indicated by the same
+   extension.  For example, the :file:`.tgz` extension is mapped to :file:`.tar.gz`
+   to allow the encoding and type to be recognized separately.
+
+
+.. data:: encodings_map
+
+   Dictionary mapping filename extensions to encoding types.
+
+
+.. data:: types_map
+
+   Dictionary mapping filename extensions to MIME types.
+
+
+.. data:: common_types
+
+   Dictionary mapping filename extensions to non-standard, but commonly found MIME
+   types.
+
+The :class:`MimeTypes` class may be useful for applications which may want more
+than one MIME-type database:
+
+
+.. class:: MimeTypes([filenames])
+
+   This class represents a MIME-types database.  By default, it provides access to
+   the same database as the rest of this module. The initial database is a copy of
+   that provided by the module, and may be extended by loading additional
+   :file:`mime.types`\ -style files into the database using the :meth:`read` or
+   :meth:`readfp` methods.  The mapping dictionaries may also be cleared before
+   loading additional data if the default data is not desired.
+
+   The optional *filenames* parameter can be used to cause additional files to be
+   loaded "on top" of the default database.
+
+   .. versionadded:: 2.2
+
+An example usage of the module::
+
+   >>> import mimetypes
+   >>> mimetypes.init()
+   >>> mimetypes.knownfiles
+   ['/etc/mime.types', '/etc/httpd/mime.types', ... ]
+   >>> mimetypes.suffix_map['.tgz']
+   '.tar.gz'
+   >>> mimetypes.encodings_map['.gz']
+   'gzip'
+   >>> mimetypes.types_map['.tgz']
+   'application/x-tar-gz'
+
+
+.. _mimetypes-objects:
+
+MimeTypes Objects
+-----------------
+
+:class:`MimeTypes` instances provide an interface which is very like that of the
+:mod:`mimetypes` module.
+
+
+.. attribute:: MimeTypes.suffix_map
+
+   Dictionary mapping suffixes to suffixes.  This is used to allow recognition of
+   encoded files for which the encoding and the type are indicated by the same
+   extension.  For example, the :file:`.tgz` extension is mapped to :file:`.tar.gz`
+   to allow the encoding and type to be recognized separately.  This is initially a
+   copy of the global ``suffix_map`` defined in the module.
+
+
+.. attribute:: MimeTypes.encodings_map
+
+   Dictionary mapping filename extensions to encoding types.  This is initially a
+   copy of the global ``encodings_map`` defined in the module.
+
+
+.. attribute:: MimeTypes.types_map
+
+   Dictionary mapping filename extensions to MIME types.  This is initially a copy
+   of the global ``types_map`` defined in the module.
+
+
+.. attribute:: MimeTypes.common_types
+
+   Dictionary mapping filename extensions to non-standard, but commonly found MIME
+   types.  This is initially a copy of the global ``common_types`` defined in the
+   module.
+
+
+.. method:: MimeTypes.guess_extension(type[, strict])
+
+   Similar to the :func:`guess_extension` function, using the tables stored as part
+   of the object.
+
+
+.. method:: MimeTypes.guess_type(url[, strict])
+
+   Similar to the :func:`guess_type` function, using the tables stored as part of
+   the object.
+
+
+.. method:: MimeTypes.read(path)
+
+   Load MIME information from a file named *path*.  This uses :meth:`readfp` to
+   parse the file.
+
+
+.. method:: MimeTypes.readfp(file)
+
+   Load MIME type information from an open file.  The file must have the format of
+   the standard :file:`mime.types` files.
+
diff --git a/Doc/library/miniaeframe.rst b/Doc/library/miniaeframe.rst
new file mode 100644
index 0000000..5bf1b07
--- /dev/null
+++ b/Doc/library/miniaeframe.rst
@@ -0,0 +1,68 @@
+
+:mod:`MiniAEFrame` --- Open Scripting Architecture server support
+=================================================================
+
+.. module:: MiniAEFrame
+   :platform: Mac
+   :synopsis: Support to act as an Open Scripting Architecture (OSA) server ("Apple Events").
+
+
+.. index::
+   single: Open Scripting Architecture
+   single: AppleEvents
+   module: FrameWork
+
+The module :mod:`MiniAEFrame` provides a framework for an application that can
+function as an Open Scripting Architecture  (OSA) server, i.e. receive and
+process AppleEvents. It can be used in conjunction with :mod:`FrameWork` or
+standalone. As an example, it is used in :program:`PythonCGISlave`.
+
+The :mod:`MiniAEFrame` module defines the following classes:
+
+
+.. class:: AEServer()
+
+   A class that handles AppleEvent dispatch. Your application should subclass this
+   class together with either :class:`MiniApplication` or
+   :class:`FrameWork.Application`. Your :meth:`__init__` method should call the
+   :meth:`__init__` method for both classes.
+
+
+.. class:: MiniApplication()
+
+   A class that is more or less compatible with :class:`FrameWork.Application` but
+   with less functionality. Its event loop supports the apple menu, command-dot and
+   AppleEvents; other events are passed on to the Python interpreter and/or Sioux.
+   Useful if your application wants to use :class:`AEServer` but does not provide
+   its own windows, etc.
+
+
+.. _aeserver-objects:
+
+AEServer Objects
+----------------
+
+
+.. method:: AEServer.installaehandler(classe, type, callback)
+
+   Installs an AppleEvent handler. *classe* and *type* are the four-character OSA
+   Class and Type designators, ``'****'`` wildcards are allowed. When a matching
+   AppleEvent is received the parameters are decoded and your callback is invoked.
+
+
+.. method:: AEServer.callback(_object, **kwargs)
+
+   Your callback is called with the OSA Direct Object as first positional
+   parameter. The other parameters are passed as keyword arguments, with the
+   4-character designator as name. Three extra keyword parameters are passed:
+   ``_class`` and ``_type`` are the Class and Type designators and ``_attributes``
+   is a dictionary with the AppleEvent attributes.
+
+   The return value of your method is packed with :func:`aetools.packevent` and
+   sent as reply.
+
+Note that there are some serious problems with the current design. AppleEvents
+which have non-identifier 4-character designators for arguments are not
+implementable, and it is not possible to return an error to the originator. This
+will be addressed in a future release.
+
diff --git a/Doc/library/misc.rst b/Doc/library/misc.rst
new file mode 100644
index 0000000..ee22561
--- /dev/null
+++ b/Doc/library/misc.rst
@@ -0,0 +1,14 @@
+
+.. _misc:
+
+**********************
+Miscellaneous Services
+**********************
+
+The modules described in this chapter provide miscellaneous services that are
+available in all Python versions.  Here's an overview:
+
+
+.. toctree::
+
+   formatter.rst
diff --git a/Doc/library/mm.rst b/Doc/library/mm.rst
new file mode 100644
index 0000000..a7fbbec
--- /dev/null
+++ b/Doc/library/mm.rst
@@ -0,0 +1,23 @@
+
+.. _mmedia:
+
+*******************
+Multimedia Services
+*******************
+
+The modules described in this chapter implement various algorithms or interfaces
+that are mainly useful for multimedia applications.  They are available at the
+discretion of the installation.  Here's an overview:
+
+
+.. toctree::
+
+   audioop.rst
+   aifc.rst
+   sunau.rst
+   wave.rst
+   chunk.rst
+   colorsys.rst
+   imghdr.rst
+   sndhdr.rst
+   ossaudiodev.rst
diff --git a/Doc/library/mmap.rst b/Doc/library/mmap.rst
new file mode 100644
index 0000000..abe5b7b
--- /dev/null
+++ b/Doc/library/mmap.rst
@@ -0,0 +1,173 @@
+
+:mod:`mmap` --- Memory-mapped file support
+==========================================
+
+.. module:: mmap
+   :synopsis: Interface to memory-mapped files for Unix and Windows.
+
+
+Memory-mapped file objects behave like both strings and like file objects.
+Unlike normal string objects, however, these are mutable.  You can use mmap
+objects in most places where strings are expected; for example, you can use the
+:mod:`re` module to search through a memory-mapped file.  Since they're mutable,
+you can change a single character by doing ``obj[index] = 'a'``, or change a
+substring by assigning to a slice: ``obj[i1:i2] = '...'``.  You can also read
+and write data starting at the current file position, and :meth:`seek` through
+the file to different positions.
+
+A memory-mapped file is created by the :func:`mmap` function, which is different
+on Unix and on Windows.  In either case you must provide a file descriptor for a
+file opened for update. If you wish to map an existing Python file object, use
+its :meth:`fileno` method to obtain the correct value for the *fileno*
+parameter.  Otherwise, you can open the file using the :func:`os.open` function,
+which returns a file descriptor directly (the file still needs to be closed when
+done).
+
+For both the Unix and Windows versions of the function, *access* may be
+specified as an optional keyword parameter. *access* accepts one of three
+values: :const:`ACCESS_READ`, :const:`ACCESS_WRITE`, or :const:`ACCESS_COPY` to
+specify readonly, write-through or copy-on-write memory respectively. *access*
+can be used on both Unix and Windows.  If *access* is not specified, Windows
+mmap returns a write-through mapping.  The initial memory values for all three
+access types are taken from the specified file.  Assignment to an
+:const:`ACCESS_READ` memory map raises a :exc:`TypeError` exception.  Assignment
+to an :const:`ACCESS_WRITE` memory map affects both memory and the underlying
+file.  Assignment to an :const:`ACCESS_COPY` memory map affects memory but does
+not update the underlying file.
+
+.. versionchanged:: 2.5
+   To map anonymous memory, -1 should be passed as the fileno along with the
+   length.
+
+
+.. function:: mmap(fileno, length[, tagname[, access]])
+
+   **(Windows version)** Maps *length* bytes from the file specified by the file
+   handle *fileno*, and returns a mmap object.  If *length* is larger than the
+   current size of the file, the file is extended to contain *length* bytes.  If
+   *length* is ``0``, the maximum length of the map is the current size of the
+   file, except that if the file is empty Windows raises an exception (you cannot
+   create an empty mapping on Windows).
+
+   *tagname*, if specified and not ``None``, is a string giving a tag name for the
+   mapping.  Windows allows you to have many different mappings against the same
+   file.  If you specify the name of an existing tag, that tag is opened, otherwise
+   a new tag of this name is created.  If this parameter is omitted or ``None``,
+   the mapping is created without a name.  Avoiding the use of the tag parameter
+   will assist in keeping your code portable between Unix and Windows.
+
+
+.. function:: mmap(fileno, length[, flags[, prot[, access]]])
+   :noindex:
+
+   **(Unix version)** Maps *length* bytes from the file specified by the file
+   descriptor *fileno*, and returns a mmap object.  If *length* is ``0``, the
+   maximum length of the map will be the current size of the file when :func:`mmap`
+   is called.
+
+   *flags* specifies the nature of the mapping. :const:`MAP_PRIVATE` creates a
+   private copy-on-write mapping, so changes to the contents of the mmap object
+   will be private to this process, and :const:`MAP_SHARED` creates a mapping
+   that's shared with all other processes mapping the same areas of the file.  The
+   default value is :const:`MAP_SHARED`.
+
+   *prot*, if specified, gives the desired memory protection; the two most useful
+   values are :const:`PROT_READ` and :const:`PROT_WRITE`, to specify that the pages
+   may be read or written.  *prot* defaults to :const:`PROT_READ \| PROT_WRITE`.
+
+   *access* may be specified in lieu of *flags* and *prot* as an optional keyword
+   parameter.  It is an error to specify both *flags*, *prot* and *access*.  See
+   the description of *access* above for information on how to use this parameter.
+
+Memory-mapped file objects support the following methods:
+
+
+.. method:: mmap.close()
+
+   Close the file.  Subsequent calls to other methods of the object will result in
+   an exception being raised.
+
+
+.. method:: mmap.find(string[, start])
+
+   Returns the lowest index in the object where the substring *string* is found.
+   Returns ``-1`` on failure.  *start* is the index at which the search begins, and
+   defaults to zero.
+
+
+.. method:: mmap.flush([offset, size])
+
+   Flushes changes made to the in-memory copy of a file back to disk. Without use
+   of this call there is no guarantee that changes are written back before the
+   object is destroyed.  If *offset* and *size* are specified, only changes to the
+   given range of bytes will be flushed to disk; otherwise, the whole extent of the
+   mapping is flushed.
+
+
+.. method:: mmap.move(dest, src, count)
+
+   Copy the *count* bytes starting at offset *src* to the destination index *dest*.
+   If the mmap was created with :const:`ACCESS_READ`, then calls to move will throw
+   a :exc:`TypeError` exception.
+
+
+.. method:: mmap.read(num)
+
+   Return a string containing up to *num* bytes starting from the current file
+   position; the file position is updated to point after the bytes that were
+   returned.
+
+
+.. method:: mmap.read_byte()
+
+   Returns a string of length 1 containing the character at the current file
+   position, and advances the file position by 1.
+
+
+.. method:: mmap.readline()
+
+   Returns a single line, starting at the current file position and up to the next
+   newline.
+
+
+.. method:: mmap.resize(newsize)
+
+   Resizes the map and the underlying file, if any. If the mmap was created with
+   :const:`ACCESS_READ` or :const:`ACCESS_COPY`, resizing the map will throw a
+   :exc:`TypeError` exception.
+
+
+.. method:: mmap.seek(pos[, whence])
+
+   Set the file's current position.  *whence* argument is optional and defaults to
+   ``os.SEEK_SET`` or ``0`` (absolute file positioning); other values are
+   ``os.SEEK_CUR`` or ``1`` (seek relative to the current position) and
+   ``os.SEEK_END`` or ``2`` (seek relative to the file's end).
+
+
+.. method:: mmap.size()
+
+   Return the length of the file, which can be larger than the size of the
+   memory-mapped area.
+
+
+.. method:: mmap.tell()
+
+   Returns the current position of the file pointer.
+
+
+.. method:: mmap.write(string)
+
+   Write the bytes in *string* into memory at the current position of the file
+   pointer; the file position is updated to point after the bytes that were
+   written. If the mmap was created with :const:`ACCESS_READ`, then writing to it
+   will throw a :exc:`TypeError` exception.
+
+
+.. method:: mmap.write_byte(byte)
+
+   Write the single-character string *byte* into memory at the current position of
+   the file pointer; the file position is advanced by ``1``. If the mmap was
+   created with :const:`ACCESS_READ`, then writing to it will throw a
+   :exc:`TypeError` exception.
+
diff --git a/Doc/library/modulefinder.rst b/Doc/library/modulefinder.rst
new file mode 100644
index 0000000..334bd5d
--- /dev/null
+++ b/Doc/library/modulefinder.rst
@@ -0,0 +1,52 @@
+
+:mod:`modulefinder` --- Find modules used by a script
+=====================================================
+
+.. sectionauthor:: A.M. Kuchling 
+
+
+.. module:: modulefinder
+   :synopsis: Find modules used by a script.
+
+
+.. versionadded:: 2.3
+
+This module provides a :class:`ModuleFinder` class that can be used to determine
+the set of modules imported by a script. ``modulefinder.py`` can also be run as
+a script, giving the filename of a Python script as its argument, after which a
+report of the imported modules will be printed.
+
+
+.. function:: AddPackagePath(pkg_name, path)
+
+   Record that the package named *pkg_name* can be found in the specified *path*.
+
+
+.. function:: ReplacePackage(oldname, newname)
+
+   Allows specifying that the module named *oldname* is in fact the package named
+   *newname*.  The most common usage would be  to handle how the :mod:`_xmlplus`
+   package replaces the :mod:`xml` package.
+
+
+.. class:: ModuleFinder([path=None, debug=0, excludes=[], replace_paths=[]])
+
+   This class provides :meth:`run_script` and :meth:`report` methods to determine
+   the set of modules imported by a script. *path* can be a list of directories to
+   search for modules; if not specified, ``sys.path`` is used.  *debug* sets the
+   debugging level; higher values make the class print  debugging messages about
+   what it's doing. *excludes* is a list of module names to exclude from the
+   analysis. *replace_paths* is a list of ``(oldpath, newpath)`` tuples that will
+   be replaced in module paths.
+
+
+.. method:: ModuleFinder.report()
+
+   Print a report to standard output that lists the modules imported by the script
+   and their paths, as well as modules that are missing or seem to be missing.
+
+
+.. method:: ModuleFinder.run_script(pathname)
+
+   Analyze the contents of the *pathname* file, which must contain  Python code.
+
diff --git a/Doc/library/modules.rst b/Doc/library/modules.rst
new file mode 100644
index 0000000..2590a3a
--- /dev/null
+++ b/Doc/library/modules.rst
@@ -0,0 +1,20 @@
+
+.. _modules:
+
+*****************
+Importing Modules
+*****************
+
+The modules described in this chapter provide new ways to import other Python
+modules and hooks for customizing the import process.
+
+The full list of modules described in this chapter is:
+
+
+.. toctree::
+
+   imp.rst
+   zipimport.rst
+   pkgutil.rst
+   modulefinder.rst
+   runpy.rst
diff --git a/Doc/library/msilib.rst b/Doc/library/msilib.rst
new file mode 100644
index 0000000..6c7955a
--- /dev/null
+++ b/Doc/library/msilib.rst
@@ -0,0 +1,537 @@
+
+:mod:`msilib` --- Read and write Microsoft Installer files
+==========================================================
+
+.. module:: msilib
+   :platform: Windows
+   :synopsis: Creation of Microsoft Installer files, and CAB files.
+.. moduleauthor:: Martin v. Löwis 
+.. sectionauthor:: Martin v. Löwis 
+
+
+.. index:: single: msi
+
+.. versionadded:: 2.5
+
+The :mod:`msilib` supports the creation of Microsoft Installer (``.msi``) files.
+Because these files often contain an embedded "cabinet" file (``.cab``), it also
+exposes an API to create CAB files. Support for reading ``.cab`` files is
+currently not implemented; read support for the ``.msi`` database is possible.
+
+This package aims to provide complete access to all tables in an ``.msi`` file,
+therefore, it is a fairly low-level API. Two primary applications of this
+package are the :mod:`distutils` command ``bdist_msi``, and the creation of
+Python installer package itself (although that currently uses a different
+version of ``msilib``).
+
+The package contents can be roughly split into four parts: low-level CAB
+routines, low-level MSI routines, higher-level MSI routines, and standard table
+structures.
+
+
+.. function:: FCICreate(cabname, files)
+
+   Create a new CAB file named *cabname*. *files* must be a list of tuples, each
+   containing the name of the file on disk, and the name of the file inside the CAB
+   file.
+
+   The files are added to the CAB file in the order they appear in the list. All
+   files are added into a single CAB file, using the MSZIP compression algorithm.
+
+   Callbacks to Python for the various steps of MSI creation are currently not
+   exposed.
+
+
+.. function:: UUIDCreate()
+
+   Return the string representation of a new unique identifier. This wraps the
+   Windows API functions :cfunc:`UuidCreate` and :cfunc:`UuidToString`.
+
+
+.. function:: OpenDatabase(path, persist)
+
+   Return a new database object by calling MsiOpenDatabase.   *path* is the file
+   name of the MSI file; *persist* can be one of the constants
+   ``MSIDBOPEN_CREATEDIRECT``, ``MSIDBOPEN_CREATE``, ``MSIDBOPEN_DIRECT``,
+   ``MSIDBOPEN_READONLY``, or ``MSIDBOPEN_TRANSACT``, and may include the flag
+   ``MSIDBOPEN_PATCHFILE``. See the Microsoft documentation for the meaning of
+   these flags; depending on the flags, an existing database is opened, or a new
+   one created.
+
+
+.. function:: CreateRecord(count)
+
+   Return a new record object by calling :cfunc:`MSICreateRecord`. *count* is the
+   number of fields of the record.
+
+
+.. function:: init_database(name, schema, ProductName, ProductCode, ProductVersion, Manufacturer)
+
+   Create and return a new database *name*, initialize it  with *schema*,  and set
+   the properties *ProductName*, *ProductCode*, *ProductVersion*, and
+   *Manufacturer*.
+
+   *schema* must be a module object containing ``tables`` and
+   ``_Validation_records`` attributes; typically, :mod:`msilib.schema` should be
+   used.
+
+   The database will contain just the schema and the validation records when this
+   function returns.
+
+
+.. function:: add_data(database, records)
+
+   Add all *records* to *database*.  *records* should be a list of tuples, each one
+   containing all fields of a record according to the schema of the table.  For
+   optional fields, ``None`` can be passed.
+
+   Field values can be int or long numbers, strings, or instances of the Binary
+   class.
+
+
+.. class:: Binary(filename)
+
+   Represents entries in the Binary table; inserting such an object using
+   :func:`add_data` reads the file named *filename* into the table.
+
+
+.. function:: add_tables(database, module)
+
+   Add all table content from *module* to *database*. *module* must contain an
+   attribute *tables* listing all tables for which content should be added, and one
+   attribute per table that has the actual content.
+
+   This is typically used to install the sequence tables.
+
+
+.. function:: add_stream(database, name, path)
+
+   Add the file *path* into the ``_Stream`` table of *database*, with the stream
+   name *name*.
+
+
+.. function:: gen_uuid()
+
+   Return a new UUID, in the format that MSI typically requires (i.e. in curly
+   braces, and with all hexdigits in upper-case).
+
+
+.. seealso::
+
+   `FCICreateFile `_
+   `UuidCreate `_
+   `UuidToString `_
+
+.. _database-objects:
+
+Database Objects
+----------------
+
+
+.. method:: Database.OpenView(sql)
+
+   Return a view object, by calling :cfunc:`MSIDatabaseOpenView`. *sql* is the SQL
+   statement to execute.
+
+
+.. method:: Database.Commit()
+
+   Commit the changes pending in the current transaction, by calling
+   :cfunc:`MSIDatabaseCommit`.
+
+
+.. method:: Database.GetSummaryInformation(count)
+
+   Return a new summary information object, by calling
+   :cfunc:`MsiGetSummaryInformation`.  *count* is the maximum number of updated
+   values.
+
+
+.. seealso::
+
+   `MSIOpenView `_
+   `MSIDatabaseCommit `_
+   `MSIGetSummaryInformation `_
+
+.. _view-objects:
+
+View Objects
+------------
+
+
+.. method:: View.Execute([params=None])
+
+   Execute the SQL query of the view, through :cfunc:`MSIViewExecute`. *params* is
+   an optional record describing actual values of the parameter tokens in the
+   query.
+
+
+.. method:: View.GetColumnInfo(kind)
+
+   Return a record describing the columns of the view, through calling
+   :cfunc:`MsiViewGetColumnInfo`. *kind* can be either ``MSICOLINFO_NAMES`` or
+   ``MSICOLINFO_TYPES``.
+
+
+.. method:: View.Fetch()
+
+   Return a result record of the query, through calling :cfunc:`MsiViewFetch`.
+
+
+.. method:: View.Modify(kind, data)
+
+   Modify the view, by calling :cfunc:`MsiViewModify`. *kind* can be one of
+   ``MSIMODIFY_SEEK``, ``MSIMODIFY_REFRESH``, ``MSIMODIFY_INSERT``,
+   ``MSIMODIFY_UPDATE``, ``MSIMODIFY_ASSIGN``, ``MSIMODIFY_REPLACE``,
+   ``MSIMODIFY_MERGE``, ``MSIMODIFY_DELETE``, ``MSIMODIFY_INSERT_TEMPORARY``,
+   ``MSIMODIFY_VALIDATE``, ``MSIMODIFY_VALIDATE_NEW``,
+   ``MSIMODIFY_VALIDATE_FIELD``, or ``MSIMODIFY_VALIDATE_DELETE``.
+
+   *data* must be a record describing the new data.
+
+
+.. method:: View.Close()
+
+   Close the view, through :cfunc:`MsiViewClose`.
+
+
+.. seealso::
+
+   `MsiViewExecute `_
+   `MSIViewGetColumnInfo `_
+   `MsiViewFetch `_
+   `MsiViewModify `_
+   `MsiViewClose `_
+
+.. _summary-objects:
+
+Summary Information Objects
+---------------------------
+
+
+.. method:: SummaryInformation.GetProperty(field)
+
+   Return a property of the summary, through :cfunc:`MsiSummaryInfoGetProperty`.
+   *field* is the name of the property, and can be one of the constants
+   ``PID_CODEPAGE``, ``PID_TITLE``, ``PID_SUBJECT``, ``PID_AUTHOR``,
+   ``PID_KEYWORDS``, ``PID_COMMENTS``, ``PID_TEMPLATE``, ``PID_LASTAUTHOR``,
+   ``PID_REVNUMBER``, ``PID_LASTPRINTED``, ``PID_CREATE_DTM``,
+   ``PID_LASTSAVE_DTM``, ``PID_PAGECOUNT``, ``PID_WORDCOUNT``, ``PID_CHARCOUNT``,
+   ``PID_APPNAME``, or ``PID_SECURITY``.
+
+
+.. method:: SummaryInformation.GetPropertyCount()
+
+   Return the number of summary properties, through
+   :cfunc:`MsiSummaryInfoGetPropertyCount`.
+
+
+.. method:: SummaryInformation.SetProperty(field, value)
+
+   Set a property through :cfunc:`MsiSummaryInfoSetProperty`. *field* can have the
+   same values as in :meth:`GetProperty`, *value* is the new value of the property.
+   Possible value types are integer and string.
+
+
+.. method:: SummaryInformation.Persist()
+
+   Write the modified properties to the summary information stream, using
+   :cfunc:`MsiSummaryInfoPersist`.
+
+
+.. seealso::
+
+   `MsiSummaryInfoGetProperty `_
+   `MsiSummaryInfoGetPropertyCount `_
+   `MsiSummaryInfoSetProperty `_
+   `MsiSummaryInfoPersist `_
+
+.. _record-objects:
+
+Record Objects
+--------------
+
+
+.. method:: Record.GetFieldCount()
+
+   Return the number of fields of the record, through
+   :cfunc:`MsiRecordGetFieldCount`.
+
+
+.. method:: Record.SetString(field, value)
+
+   Set *field* to *value* through :cfunc:`MsiRecordSetString`. *field* must be an
+   integer; *value* a string.
+
+
+.. method:: Record.SetStream(field, value)
+
+   Set *field* to the contents of the file named *value*, through
+   :cfunc:`MsiRecordSetStream`. *field* must be an integer; *value* a string.
+
+
+.. method:: Record.SetInteger(field, value)
+
+   Set *field* to *value* through :cfunc:`MsiRecordSetInteger`. Both *field* and
+   *value* must be an integer.
+
+
+.. method:: Record.ClearData()
+
+   Set all fields of the record to 0, through :cfunc:`MsiRecordClearData`.
+
+
+.. seealso::
+
+   `MsiRecordGetFieldCount `_
+   `MsiRecordSetString `_
+   `MsiRecordSetStream `_
+   `MsiRecordSetInteger `_
+   `MsiRecordClear `_
+
+.. _msi-errors:
+
+Errors
+------
+
+All wrappers around MSI functions raise :exc:`MsiError`; the string inside the
+exception will contain more detail.
+
+
+.. _cab:
+
+CAB Objects
+-----------
+
+
+.. class:: CAB(name)
+
+   The class :class:`CAB` represents a CAB file. During MSI construction, files
+   will be added simultaneously to the ``Files`` table, and to a CAB file. Then,
+   when all files have been added, the CAB file can be written, then added to the
+   MSI file.
+
+   *name* is the name of the CAB file in the MSI file.
+
+
+.. method:: CAB.append(full, file, logical)
+
+   Add the file with the pathname *full* to the CAB file, under the name *logical*.
+   If there is already a file named *logical*, a new file name is created.
+
+   Return the index of the file in the CAB file, and the new name of the file
+   inside the CAB file.
+
+
+.. method:: CAB.commit(database)
+
+   Generate a CAB file, add it as a stream to the MSI file, put it into the
+   ``Media`` table, and remove the generated file from the disk.
+
+
+.. _msi-directory:
+
+Directory Objects
+-----------------
+
+
+.. class:: Directory(database, cab, basedir, physical,  logical, default, component, [componentflags])
+
+   Create a new directory in the Directory table. There is a current component at
+   each point in time for the directory, which is either explicitly created through
+   :meth:`start_component`, or implicitly when files are added for the first time.
+   Files are added into the current component, and into the cab file.  To create a
+   directory, a base directory object needs to be specified (can be ``None``), the
+   path to the physical directory, and a logical directory name.  *default*
+   specifies the DefaultDir slot in the directory table. *componentflags* specifies
+   the default flags that new components get.
+
+
+.. method:: Directory.start_component([component[, feature[, flags[, keyfile[, uuid]]]]])
+
+   Add an entry to the Component table, and make this component the current
+   component for this directory. If no component name is given, the directory name
+   is used. If no *feature* is given, the current feature is used. If no *flags*
+   are given, the directory's default flags are used. If no *keyfile* is given, the
+   KeyPath is left null in the Component table.
+
+
+.. method:: Directory.add_file(file[, src[, version[, language]]])
+
+   Add a file to the current component of the directory, starting a new one if
+   there is no current component. By default, the file name in the source and the
+   file table will be identical. If the *src* file is specified, it is interpreted
+   relative to the current directory. Optionally, a *version* and a *language* can
+   be specified for the entry in the File table.
+
+
+.. method:: Directory.glob(pattern[, exclude])
+
+   Add a list of files to the current component as specified in the glob pattern.
+   Individual files can be excluded in the *exclude* list.
+
+
+.. method:: Directory.remove_pyc()
+
+   Remove ``.pyc``/``.pyo`` files on uninstall.
+
+
+.. seealso::
+
+   `Directory Table `_
+   `File Table `_
+   `Component Table `_
+   `FeatureComponents Table `_
+
+.. _features:
+
+Features
+--------
+
+
+.. class:: Feature(database, id, title, desc, display[, level=1[, parent[, directory[,  attributes=0]]]])
+
+   Add a new record to the ``Feature`` table, using the values *id*, *parent.id*,
+   *title*, *desc*, *display*, *level*, *directory*, and *attributes*. The
+   resulting feature object can be passed to the :meth:`start_component` method of
+   :class:`Directory`.
+
+
+.. method:: Feature.set_current()
+
+   Make this feature the current feature of :mod:`msilib`. New components are
+   automatically added to the default feature, unless a feature is explicitly
+   specified.
+
+
+.. seealso::
+
+   `Feature Table `_
+
+.. _msi-gui:
+
+GUI classes
+-----------
+
+:mod:`msilib` provides several classes that wrap the GUI tables in an MSI
+database. However, no standard user interface is provided; use :mod:`bdist_msi`
+to create MSI files with a user-interface for installing Python packages.
+
+
+.. class:: Control(dlg, name)
+
+   Base class of the dialog controls. *dlg* is the dialog object the control
+   belongs to, and *name* is the control's name.
+
+
+.. method:: Control.event(event, argument[,  condition=1[, ordering]])
+
+   Make an entry into the ``ControlEvent`` table for this control.
+
+
+.. method:: Control.mapping(event, attribute)
+
+   Make an entry into the ``EventMapping`` table for this control.
+
+
+.. method:: Control.condition(action, condition)
+
+   Make an entry into the ``ControlCondition`` table for this control.
+
+
+.. class:: RadioButtonGroup(dlg, name, property)
+
+   Create a radio button control named *name*. *property* is the installer property
+   that gets set when a radio button is selected.
+
+
+.. method:: RadioButtonGroup.add(name, x, y, width, height, text [, value])
+
+   Add a radio button named *name* to the group, at the coordinates *x*, *y*,
+   *width*, *height*, and with the label *text*. If *value* is omitted, it defaults
+   to *name*.
+
+
+.. class:: Dialog(db, name, x, y, w, h, attr, title, first,  default, cancel)
+
+   Return a new :class:`Dialog` object. An entry in the ``Dialog`` table is made,
+   with the specified coordinates, dialog attributes, title, name of the first,
+   default, and cancel controls.
+
+
+.. method:: Dialog.control(name, type, x, y, width, height,  attributes, property, text, control_next, help)
+
+   Return a new :class:`Control` object. An entry in the ``Control`` table is made
+   with the specified parameters.
+
+   This is a generic method; for specific types, specialized methods are provided.
+
+
+.. method:: Dialog.text(name, x, y, width, height, attributes, text)
+
+   Add and return a ``Text`` control.
+
+
+.. method:: Dialog.bitmap(name, x, y, width, height, text)
+
+   Add and return a ``Bitmap`` control.
+
+
+.. method:: Dialog.line(name, x, y, width, height)
+
+   Add and return a ``Line`` control.
+
+
+.. method:: Dialog.pushbutton(name, x, y, width, height, attributes,  text, next_control)
+
+   Add and return a ``PushButton`` control.
+
+
+.. method:: Dialog.radiogroup(name, x, y, width, height,  attributes, property, text, next_control)
+
+   Add and return a ``RadioButtonGroup`` control.
+
+
+.. method:: Dialog.checkbox(name, x, y, width, height,  attributes, property, text, next_control)
+
+   Add and return a ``CheckBox`` control.
+
+
+.. seealso::
+
+   `Dialog Table `_
+   `Control Table `_
+   `Control Types `_
+   `ControlCondition Table `_
+   `ControlEvent Table `_
+   `EventMapping Table `_
+   `RadioButton Table `_
+
+.. _msi-tables:
+
+Precomputed tables
+------------------
+
+:mod:`msilib` provides a few subpackages that contain only schema and table
+definitions. Currently, these definitions are based on MSI version 2.0.
+
+
+.. data:: schema
+
+   This is the standard MSI schema for MSI 2.0, with the *tables* variable
+   providing a list of table definitions, and *_Validation_records* providing the
+   data for MSI validation.
+
+
+.. data:: sequence
+
+   This module contains table contents for the standard sequence tables:
+   *AdminExecuteSequence*, *AdminUISequence*, *AdvtExecuteSequence*,
+   *InstallExecuteSequence*, and *InstallUISequence*.
+
+
+.. data:: text
+
+   This module contains definitions for the UIText and ActionText tables, for the
+   standard installer actions.
+
diff --git a/Doc/library/msvcrt.rst b/Doc/library/msvcrt.rst
new file mode 100644
index 0000000..d43bb4c
--- /dev/null
+++ b/Doc/library/msvcrt.rst
@@ -0,0 +1,126 @@
+
+:mod:`msvcrt` -- Useful routines from the MS VC++ runtime
+=========================================================
+
+.. module:: msvcrt
+   :platform: Windows
+   :synopsis: Miscellaneous useful routines from the MS VC++ runtime.
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+These functions provide access to some useful capabilities on Windows platforms.
+Some higher-level modules use these functions to build the  Windows
+implementations of their services.  For example, the :mod:`getpass` module uses
+this in the implementation of the :func:`getpass` function.
+
+Further documentation on these functions can be found in the Platform API
+documentation.
+
+
+.. _msvcrt-files:
+
+File Operations
+---------------
+
+
+.. function:: locking(fd, mode, nbytes)
+
+   Lock part of a file based on file descriptor *fd* from the C runtime.  Raises
+   :exc:`IOError` on failure.  The locked region of the file extends from the
+   current file position for *nbytes* bytes, and may continue beyond the end of the
+   file.  *mode* must be one of the :const:`LK_\*` constants listed below. Multiple
+   regions in a file may be locked at the same time, but may not overlap.  Adjacent
+   regions are not merged; they must be unlocked individually.
+
+
+.. data:: LK_LOCK
+          LK_RLCK
+
+   Locks the specified bytes. If the bytes cannot be locked, the program
+   immediately tries again after 1 second.  If, after 10 attempts, the bytes cannot
+   be locked, :exc:`IOError` is raised.
+
+
+.. data:: LK_NBLCK
+          LK_NBRLCK
+
+   Locks the specified bytes. If the bytes cannot be locked, :exc:`IOError` is
+   raised.
+
+
+.. data:: LK_UNLCK
+
+   Unlocks the specified bytes, which must have been previously locked.
+
+
+.. function:: setmode(fd, flags)
+
+   Set the line-end translation mode for the file descriptor *fd*. To set it to
+   text mode, *flags* should be :const:`os.O_TEXT`; for binary, it should be
+   :const:`os.O_BINARY`.
+
+
+.. function:: open_osfhandle(handle, flags)
+
+   Create a C runtime file descriptor from the file handle *handle*.  The *flags*
+   parameter should be a bit-wise OR of :const:`os.O_APPEND`, :const:`os.O_RDONLY`,
+   and :const:`os.O_TEXT`.  The returned file descriptor may be used as a parameter
+   to :func:`os.fdopen` to create a file object.
+
+
+.. function:: get_osfhandle(fd)
+
+   Return the file handle for the file descriptor *fd*.  Raises :exc:`IOError` if
+   *fd* is not recognized.
+
+
+.. _msvcrt-console:
+
+Console I/O
+-----------
+
+
+.. function:: kbhit()
+
+   Return true if a keypress is waiting to be read.
+
+
+.. function:: getch()
+
+   Read a keypress and return the resulting character.  Nothing is echoed to the
+   console.  This call will block if a keypress is not already available, but will
+   not wait for :kbd:`Enter` to be pressed. If the pressed key was a special
+   function key, this will return ``'\000'`` or ``'\xe0'``; the next call will
+   return the keycode.  The :kbd:`Control-C` keypress cannot be read with this
+   function.
+
+
+.. function:: getche()
+
+   Similar to :func:`getch`, but the keypress will be echoed if it  represents a
+   printable character.
+
+
+.. function:: putch(char)
+
+   Print the character *char* to the console without buffering.
+
+
+.. function:: ungetch(char)
+
+   Cause the character *char* to be "pushed back" into the console buffer; it will
+   be the next character read by :func:`getch` or :func:`getche`.
+
+
+.. _msvcrt-other:
+
+Other Functions
+---------------
+
+
+.. function:: heapmin()
+
+   Force the :cfunc:`malloc` heap to clean itself up and return unused blocks to
+   the operating system.  This only works on Windows NT.  On failure, this raises
+   :exc:`IOError`.
+
diff --git a/Doc/library/multifile.rst b/Doc/library/multifile.rst
new file mode 100644
index 0000000..c36ccb7
--- /dev/null
+++ b/Doc/library/multifile.rst
@@ -0,0 +1,190 @@
+
+:mod:`multifile` --- Support for files containing distinct parts
+================================================================
+
+.. module:: multifile
+   :synopsis: Support for reading files which contain distinct parts, such as some MIME data.
+.. sectionauthor:: Eric S. Raymond 
+
+
+.. deprecated:: 2.5
+   The :mod:`email` package should be used in preference to the :mod:`multifile`
+   module. This module is present only to maintain backward compatibility.
+
+The :class:`MultiFile` object enables you to treat sections of a text file as
+file-like input objects, with ``''`` being returned by :meth:`readline` when a
+given delimiter pattern is encountered.  The defaults of this class are designed
+to make it useful for parsing MIME multipart messages, but by subclassing it and
+overriding methods  it can be easily adapted for more general use.
+
+
+.. class:: MultiFile(fp[, seekable])
+
+   Create a multi-file.  You must instantiate this class with an input object
+   argument for the :class:`MultiFile` instance to get lines from, such as a file
+   object returned by :func:`open`.
+
+   :class:`MultiFile` only ever looks at the input object's :meth:`readline`,
+   :meth:`seek` and :meth:`tell` methods, and the latter two are only needed if you
+   want random access to the individual MIME parts. To use :class:`MultiFile` on a
+   non-seekable stream object, set the optional *seekable* argument to false; this
+   will prevent using the input object's :meth:`seek` and :meth:`tell` methods.
+
+It will be useful to know that in :class:`MultiFile`'s view of the world, text
+is composed of three kinds of lines: data, section-dividers, and end-markers.
+MultiFile is designed to support parsing of messages that may have multiple
+nested message parts, each with its own pattern for section-divider and
+end-marker lines.
+
+
+.. seealso::
+
+   Module :mod:`email`
+      Comprehensive email handling package; supersedes the :mod:`multifile` module.
+
+
+.. _multifile-objects:
+
+MultiFile Objects
+-----------------
+
+A :class:`MultiFile` instance has the following methods:
+
+
+.. method:: MultiFile.readline(str)
+
+   Read a line.  If the line is data (not a section-divider or end-marker or real
+   EOF) return it.  If the line matches the most-recently-stacked boundary, return
+   ``''`` and set ``self.last`` to 1 or 0 according as the match is or is not an
+   end-marker.  If the line matches any other stacked boundary, raise an error.  On
+   encountering end-of-file on the underlying stream object, the method raises
+   :exc:`Error` unless all boundaries have been popped.
+
+
+.. method:: MultiFile.readlines(str)
+
+   Return all lines remaining in this part as a list of strings.
+
+
+.. method:: MultiFile.read()
+
+   Read all lines, up to the next section.  Return them as a single (multiline)
+   string.  Note that this doesn't take a size argument!
+
+
+.. method:: MultiFile.seek(pos[, whence])
+
+   Seek.  Seek indices are relative to the start of the current section. The *pos*
+   and *whence* arguments are interpreted as for a file seek.
+
+
+.. method:: MultiFile.tell()
+
+   Return the file position relative to the start of the current section.
+
+
+.. method:: MultiFile.next()
+
+   Skip lines to the next section (that is, read lines until a section-divider or
+   end-marker has been consumed).  Return true if there is such a section, false if
+   an end-marker is seen.  Re-enable the most-recently-pushed boundary.
+
+
+.. method:: MultiFile.is_data(str)
+
+   Return true if *str* is data and false if it might be a section boundary.  As
+   written, it tests for a prefix other than ``'-``\ ``-'`` at start of line (which
+   all MIME boundaries have) but it is declared so it can be overridden in derived
+   classes.
+
+   Note that this test is used intended as a fast guard for the real boundary
+   tests; if it always returns false it will merely slow processing, not cause it
+   to fail.
+
+
+.. method:: MultiFile.push(str)
+
+   Push a boundary string.  When a decorated version of this boundary  is found as
+   an input line, it will be interpreted as a section-divider  or end-marker
+   (depending on the decoration, see :rfc:`2045`).  All subsequent reads will
+   return the empty string to indicate end-of-file, until a call to :meth:`pop`
+   removes the boundary a or :meth:`next` call reenables it.
+
+   It is possible to push more than one boundary.  Encountering the
+   most-recently-pushed boundary will return EOF; encountering any other
+   boundary will raise an error.
+
+
+.. method:: MultiFile.pop()
+
+   Pop a section boundary.  This boundary will no longer be interpreted as EOF.
+
+
+.. method:: MultiFile.section_divider(str)
+
+   Turn a boundary into a section-divider line.  By default, this method
+   prepends ``'--'`` (which MIME section boundaries have) but it is declared so
+   it can be overridden in derived classes.  This method need not append LF or
+   CR-LF, as comparison with the result ignores trailing whitespace.
+
+
+.. method:: MultiFile.end_marker(str)
+
+   Turn a boundary string into an end-marker line.  By default, this method
+   prepends ``'--'`` and appends ``'--'`` (like a MIME-multipart end-of-message
+   marker) but it is declared so it can be overridden in derived classes.  This
+   method need not append LF or CR-LF, as comparison with the result ignores
+   trailing whitespace.
+
+Finally, :class:`MultiFile` instances have two public instance variables:
+
+
+.. attribute:: MultiFile.level
+
+   Nesting depth of the current part.
+
+
+.. attribute:: MultiFile.last
+
+   True if the last end-of-file was for an end-of-message marker.
+
+
+.. _multifile-example:
+
+:class:`MultiFile` Example
+--------------------------
+
+.. sectionauthor:: Skip Montanaro 
+
+
+::
+
+   import mimetools
+   import multifile
+   import StringIO
+
+   def extract_mime_part_matching(stream, mimetype):
+       """Return the first element in a multipart MIME message on stream
+       matching mimetype."""
+
+       msg = mimetools.Message(stream)
+       msgtype = msg.gettype()
+       params = msg.getplist()
+
+       data = StringIO.StringIO()
+       if msgtype[:10] == "multipart/":
+
+           file = multifile.MultiFile(stream)
+           file.push(msg.getparam("boundary"))
+           while file.next():
+               submsg = mimetools.Message(file)
+               try:
+                   data = StringIO.StringIO()
+                   mimetools.decode(file, data, submsg.getencoding())
+               except ValueError:
+                   continue
+               if submsg.gettype() == mimetype:
+                   break
+           file.pop()
+       return data.getvalue()
+
diff --git a/Doc/library/mutex.rst b/Doc/library/mutex.rst
new file mode 100644
index 0000000..523692f
--- /dev/null
+++ b/Doc/library/mutex.rst
@@ -0,0 +1,62 @@
+
+:mod:`mutex` --- Mutual exclusion support
+=========================================
+
+.. module:: mutex
+   :synopsis: Lock and queue for mutual exclusion.
+.. sectionauthor:: Moshe Zadka 
+
+
+The :mod:`mutex` module defines a class that allows mutual-exclusion via
+acquiring and releasing locks. It does not require (or imply) threading or
+multi-tasking, though it could be useful for those purposes.
+
+The :mod:`mutex` module defines the following class:
+
+
+.. class:: mutex()
+
+   Create a new (unlocked) mutex.
+
+   A mutex has two pieces of state --- a "locked" bit and a queue. When the mutex
+   is not locked, the queue is empty. Otherwise, the queue contains zero or more
+   ``(function, argument)`` pairs representing functions (or methods) waiting to
+   acquire the lock. When the mutex is unlocked while the queue is not empty, the
+   first queue entry is removed and its  ``function(argument)`` pair called,
+   implying it now has the lock.
+
+   Of course, no multi-threading is implied -- hence the funny interface for
+   :meth:`lock`, where a function is called once the lock is acquired.
+
+
+.. _mutex-objects:
+
+Mutex Objects
+-------------
+
+:class:`mutex` objects have following methods:
+
+
+.. method:: mutex.test()
+
+   Check whether the mutex is locked.
+
+
+.. method:: mutex.testandset()
+
+   "Atomic" test-and-set, grab the lock if it is not set, and return ``True``,
+   otherwise, return ``False``.
+
+
+.. method:: mutex.lock(function, argument)
+
+   Execute ``function(argument)``, unless the mutex is locked. In the case it is
+   locked, place the function and argument on the queue. See :meth:`unlock` for
+   explanation of when ``function(argument)`` is executed in that case.
+
+
+.. method:: mutex.unlock()
+
+   Unlock the mutex if queue is empty, otherwise execute the first element in the
+   queue.
+
diff --git a/Doc/library/netdata.rst b/Doc/library/netdata.rst
new file mode 100644
index 0000000..add01d2
--- /dev/null
+++ b/Doc/library/netdata.rst
@@ -0,0 +1,26 @@
+
+.. _netdata:
+
+**********************
+Internet Data Handling
+**********************
+
+This chapter describes modules which support handling data formats commonly used
+on the Internet.
+
+
+.. toctree::
+
+   email.rst
+   mailcap.rst
+   mailbox.rst
+   mhlib.rst
+   mimetools.rst
+   mimetypes.rst
+   multifile.rst
+   rfc822.rst
+   base64.rst
+   binhex.rst
+   binascii.rst
+   quopri.rst
+   uu.rst
diff --git a/Doc/library/netrc.rst b/Doc/library/netrc.rst
new file mode 100644
index 0000000..bf3d92e
--- /dev/null
+++ b/Doc/library/netrc.rst
@@ -0,0 +1,78 @@
+
+:mod:`netrc` --- netrc file processing
+======================================
+
+.. module:: netrc
+   :synopsis: Loading of .netrc files.
+.. moduleauthor:: Eric S. Raymond 
+.. sectionauthor:: Eric S. Raymond 
+
+
+.. % Note the \protect needed for \file... ;-(
+
+.. versionadded:: 1.5.2
+
+The :class:`netrc` class parses and encapsulates the netrc file format used by
+the Unix :program:`ftp` program and other FTP clients.
+
+
+.. class:: netrc([file])
+
+   A :class:`netrc` instance or subclass instance encapsulates data from  a netrc
+   file.  The initialization argument, if present, specifies the file to parse.  If
+   no argument is given, the file :file:`.netrc` in the user's home directory will
+   be read.  Parse errors will raise :exc:`NetrcParseError` with diagnostic
+   information including the file name, line number, and terminating token.
+
+
+.. exception:: NetrcParseError
+
+   Exception raised by the :class:`netrc` class when syntactical errors are
+   encountered in source text.  Instances of this exception provide three
+   interesting attributes:  :attr:`msg` is a textual explanation of the error,
+   :attr:`filename` is the name of the source file, and :attr:`lineno` gives the
+   line number on which the error was found.
+
+
+.. _netrc-objects:
+
+netrc Objects
+-------------
+
+A :class:`netrc` instance has the following methods:
+
+
+.. method:: netrc.authenticators(host)
+
+   Return a 3-tuple ``(login, account, password)`` of authenticators for *host*.
+   If the netrc file did not contain an entry for the given host, return the tuple
+   associated with the 'default' entry.  If neither matching host nor default entry
+   is available, return ``None``.
+
+
+.. method:: netrc.__repr__()
+
+   Dump the class data as a string in the format of a netrc file. (This discards
+   comments and may reorder the entries.)
+
+Instances of :class:`netrc` have public instance variables:
+
+
+.. attribute:: netrc.hosts
+
+   Dictionary mapping host names to ``(login, account, password)`` tuples.  The
+   'default' entry, if any, is represented as a pseudo-host by that name.
+
+
+.. attribute:: netrc.macros
+
+   Dictionary mapping macro names to string lists.
+
+.. note::
+
+   Passwords are limited to a subset of the ASCII character set. Versions of
+   this module prior to 2.3 were extremely limited.  Starting with 2.3, all
+   ASCII punctuation is allowed in passwords.  However, note that whitespace and
+   non-printable characters are not allowed in passwords.  This is a limitation
+   of the way the .netrc file is parsed and may be removed in the future.
+
diff --git a/Doc/library/new.rst b/Doc/library/new.rst
new file mode 100644
index 0000000..852fb58
--- /dev/null
+++ b/Doc/library/new.rst
@@ -0,0 +1,53 @@
+
+:mod:`new` --- Creation of runtime internal objects
+===================================================
+
+.. module:: new
+   :synopsis: Interface to the creation of runtime implementation objects.
+.. sectionauthor:: Moshe Zadka 
+
+
+The :mod:`new` module allows an interface to the interpreter object creation
+functions. This is for use primarily in marshal-type functions, when a new
+object needs to be created "magically" and not by using the regular creation
+functions. This module provides a low-level interface to the interpreter, so
+care must be exercised when using this module. It is possible to supply
+non-sensical arguments which crash the interpreter when the object is used.
+
+The :mod:`new` module defines the following functions:
+
+
+.. function:: instancemethod(function, instance, class)
+
+   This function will return a method object, bound to *instance*, or unbound if
+   *instance* is ``None``.  *function* must be callable.
+
+
+.. function:: function(code, globals[, name[, argdefs[, closure]]])
+
+   Returns a (Python) function with the given code and globals. If *name* is given,
+   it must be a string or ``None``.  If it is a string, the function will have the
+   given name, otherwise the function name will be taken from ``code.co_name``.  If
+   *argdefs* is given, it must be a tuple and will be used to determine the default
+   values of parameters.  If *closure* is given, it must be ``None`` or a tuple of
+   cell objects containing objects to bind to the names in ``code.co_freevars``.
+
+
+.. function:: code(argcount, nlocals, stacksize, flags, codestring, constants, names, varnames, filename, name, firstlineno, lnotab)
+
+   This function is an interface to the :cfunc:`PyCode_New` C function.
+
+   .. % XXX This is still undocumented!!!!!!!!!!!
+
+
+.. function:: module(name[, doc])
+
+   This function returns a new module object with name *name*. *name* must be a
+   string. The optional *doc* argument can have any type.
+
+
+.. function:: classobj(name, baseclasses, dict)
+
+   This function returns a new class object, with name *name*, derived from
+   *baseclasses* (which should be a tuple of classes) and with namespace *dict*.
+
diff --git a/Doc/library/nis.rst b/Doc/library/nis.rst
new file mode 100644
index 0000000..77684bf
--- /dev/null
+++ b/Doc/library/nis.rst
@@ -0,0 +1,68 @@
+
+:mod:`nis` --- Interface to Sun's NIS (Yellow Pages)
+====================================================
+
+.. module:: nis
+   :platform: Unix
+   :synopsis: Interface to Sun's NIS (Yellow Pages) library.
+.. moduleauthor:: Fred Gansevles 
+.. sectionauthor:: Moshe Zadka 
+
+
+The :mod:`nis` module gives a thin wrapper around the NIS library, useful for
+central administration of several hosts.
+
+Because NIS exists only on Unix systems, this module is only available for Unix.
+
+The :mod:`nis` module defines the following functions:
+
+
+.. function:: match(key, mapname[, domain=default_domain])
+
+   Return the match for *key* in map *mapname*, or raise an error
+   (:exc:`nis.error`) if there is none. Both should be strings, *key* is 8-bit
+   clean. Return value is an arbitrary array of bytes (may contain ``NULL`` and
+   other joys).
+
+   Note that *mapname* is first checked if it is an alias to another name.
+
+   .. versionchanged:: 2.5
+      The *domain* argument allows to override the NIS domain used for the lookup. If
+      unspecified, lookup is in the default NIS domain.
+
+
+.. function:: cat(mapname[, domain=default_domain])
+
+   Return a dictionary mapping *key* to *value* such that ``match(key,
+   mapname)==value``. Note that both keys and values of the dictionary are
+   arbitrary arrays of bytes.
+
+   Note that *mapname* is first checked if it is an alias to another name.
+
+   .. versionchanged:: 2.5
+      The *domain* argument allows to override the NIS domain used for the lookup. If
+      unspecified, lookup is in the default NIS domain.
+
+
+.. function:: maps([domain=default_domain])
+
+   Return a list of all valid maps.
+
+   .. versionchanged:: 2.5
+      The *domain* argument allows to override the NIS domain used for the lookup. If
+      unspecified, lookup is in the default NIS domain.
+
+
+.. function:: get_default_domain()
+
+   Return the system default NIS domain.
+
+   .. versionadded:: 2.5
+
+The :mod:`nis` module defines the following exception:
+
+
+.. exception:: error
+
+   An error raised when a NIS function returns an error code.
+
diff --git a/Doc/library/nntplib.rst b/Doc/library/nntplib.rst
new file mode 100644
index 0000000..5bc947e
--- /dev/null
+++ b/Doc/library/nntplib.rst
@@ -0,0 +1,350 @@
+
+:mod:`nntplib` --- NNTP protocol client
+=======================================
+
+.. module:: nntplib
+   :synopsis: NNTP protocol client (requires sockets).
+
+
+.. index::
+   pair: NNTP; protocol
+   single: Network News Transfer Protocol
+
+This module defines the class :class:`NNTP` which implements the client side of
+the NNTP protocol.  It can be used to implement a news reader or poster, or
+automated news processors.  For more information on NNTP (Network News Transfer
+Protocol), see Internet :rfc:`977`.
+
+Here are two small examples of how it can be used.  To list some statistics
+about a newsgroup and print the subjects of the last 10 articles::
+
+   >>> s = NNTP('news.cwi.nl')
+   >>> resp, count, first, last, name = s.group('comp.lang.python')
+   >>> print 'Group', name, 'has', count, 'articles, range', first, 'to', last
+   Group comp.lang.python has 59 articles, range 3742 to 3803
+   >>> resp, subs = s.xhdr('subject', first + '-' + last)
+   >>> for id, sub in subs[-10:]: print id, sub
+   ... 
+   3792 Re: Removing elements from a list while iterating...
+   3793 Re: Who likes Info files?
+   3794 Emacs and doc strings
+   3795 a few questions about the Mac implementation
+   3796 Re: executable python scripts
+   3797 Re: executable python scripts
+   3798 Re: a few questions about the Mac implementation 
+   3799 Re: PROPOSAL: A Generic Python Object Interface for Python C Modules
+   3802 Re: executable python scripts 
+   3803 Re: \POSIX{} wait and SIGCHLD
+   >>> s.quit()
+   '205 news.cwi.nl closing connection.  Goodbye.'
+
+To post an article from a file (this assumes that the article has valid
+headers)::
+
+   >>> s = NNTP('news.cwi.nl')
+   >>> f = open('/tmp/article')
+   >>> s.post(f)
+   '240 Article posted successfully.'
+   >>> s.quit()
+   '205 news.cwi.nl closing connection.  Goodbye.'
+
+The module itself defines the following items:
+
+
+.. class:: NNTP(host[, port [, user[, password [, readermode] [, usenetrc]]]])
+
+   Return a new instance of the :class:`NNTP` class, representing a connection
+   to the NNTP server running on host *host*, listening at port *port*.  The
+   default *port* is 119.  If the optional *user* and *password* are provided,
+   or if suitable credentials are present in :file:`/.netrc` and the optional
+   flag *usenetrc* is true (the default), the ``AUTHINFO USER`` and ``AUTHINFO
+   PASS`` commands are used to identify and authenticate the user to the server.
+   If the optional flag *readermode* is true, then a ``mode reader`` command is
+   sent before authentication is performed.  Reader mode is sometimes necessary
+   if you are connecting to an NNTP server on the local machine and intend to
+   call reader-specific commands, such as ``group``.  If you get unexpected
+   :exc:`NNTPPermanentError`\ s, you might need to set *readermode*.
+   *readermode* defaults to ``None``. *usenetrc* defaults to ``True``.
+
+   .. versionchanged:: 2.4
+      *usenetrc* argument added.
+
+
+.. exception:: NNTPError
+
+   Derived from the standard exception :exc:`Exception`, this is the base class for
+   all exceptions raised by the :mod:`nntplib` module.
+
+
+.. exception:: NNTPReplyError
+
+   Exception raised when an unexpected reply is received from the server.  For
+   backwards compatibility, the exception ``error_reply`` is equivalent to this
+   class.
+
+
+.. exception:: NNTPTemporaryError
+
+   Exception raised when an error code in the range 400--499 is received.  For
+   backwards compatibility, the exception ``error_temp`` is equivalent to this
+   class.
+
+
+.. exception:: NNTPPermanentError
+
+   Exception raised when an error code in the range 500--599 is received.  For
+   backwards compatibility, the exception ``error_perm`` is equivalent to this
+   class.
+
+
+.. exception:: NNTPProtocolError
+
+   Exception raised when a reply is received from the server that does not begin
+   with a digit in the range 1--5.  For backwards compatibility, the exception
+   ``error_proto`` is equivalent to this class.
+
+
+.. exception:: NNTPDataError
+
+   Exception raised when there is some error in the response data.  For backwards
+   compatibility, the exception ``error_data`` is equivalent to this class.
+
+
+.. _nntp-objects:
+
+NNTP Objects
+------------
+
+NNTP instances have the following methods.  The *response* that is returned as
+the first item in the return tuple of almost all methods is the server's
+response: a string beginning with a three-digit code. If the server's response
+indicates an error, the method raises one of the above exceptions.
+
+
+.. method:: NNTP.getwelcome()
+
+   Return the welcome message sent by the server in reply to the initial
+   connection.  (This message sometimes contains disclaimers or help information
+   that may be relevant to the user.)
+
+
+.. method:: NNTP.set_debuglevel(level)
+
+   Set the instance's debugging level.  This controls the amount of debugging
+   output printed.  The default, ``0``, produces no debugging output.  A value of
+   ``1`` produces a moderate amount of debugging output, generally a single line
+   per request or response.  A value of ``2`` or higher produces the maximum amount
+   of debugging output, logging each line sent and received on the connection
+   (including message text).
+
+
+.. method:: NNTP.newgroups(date, time, [file])
+
+   Send a ``NEWGROUPS`` command.  The *date* argument should be a string of the
+   form ``'yymmdd'`` indicating the date, and *time* should be a string of the form
+   ``'hhmmss'`` indicating the time.  Return a pair ``(response, groups)`` where
+   *groups* is a list of group names that are new since the given date and time. If
+   the *file* parameter is supplied, then the output of the  ``NEWGROUPS`` command
+   is stored in a file.  If *file* is a string,  then the method will open a file
+   object with that name, write to it  then close it.  If *file* is a file object,
+   then it will start calling :meth:`write` on it to store the lines of the command
+   output. If *file* is supplied, then the returned *list* is an empty list.
+
+
+.. method:: NNTP.newnews(group, date, time, [file])
+
+   Send a ``NEWNEWS`` command.  Here, *group* is a group name or ``'*'``, and
+   *date* and *time* have the same meaning as for :meth:`newgroups`.  Return a pair
+   ``(response, articles)`` where *articles* is a list of message ids. If the
+   *file* parameter is supplied, then the output of the  ``NEWNEWS`` command is
+   stored in a file.  If *file* is a string,  then the method will open a file
+   object with that name, write to it  then close it.  If *file* is a file object,
+   then it will start calling :meth:`write` on it to store the lines of the command
+   output. If *file* is supplied, then the returned *list* is an empty list.
+
+
+.. method:: NNTP.list([file])
+
+   Send a ``LIST`` command.  Return a pair ``(response, list)`` where *list* is a
+   list of tuples.  Each tuple has the form ``(group, last, first, flag)``, where
+   *group* is a group name, *last* and *first* are the last and first article
+   numbers (as strings), and *flag* is ``'y'`` if posting is allowed, ``'n'`` if
+   not, and ``'m'`` if the newsgroup is moderated.  (Note the ordering: *last*,
+   *first*.) If the *file* parameter is supplied, then the output of the  ``LIST``
+   command is stored in a file.  If *file* is a string,  then the method will open
+   a file object with that name, write to it  then close it.  If *file* is a file
+   object, then it will start calling :meth:`write` on it to store the lines of the
+   command output. If *file* is supplied, then the returned *list* is an empty
+   list.
+
+
+.. method:: NNTP.descriptions(grouppattern)
+
+   Send a ``LIST NEWSGROUPS`` command, where *grouppattern* is a wildmat string as
+   specified in RFC2980 (it's essentially the same as DOS or UNIX shell wildcard
+   strings).  Return a pair ``(response, list)``, where *list* is a list of tuples
+   containing ``(name, title)``.
+
+   .. versionadded:: 2.4
+
+
+.. method:: NNTP.description(group)
+
+   Get a description for a single group *group*.  If more than one group matches
+   (if 'group' is a real wildmat string), return the first match.   If no group
+   matches, return an empty string.
+
+   This elides the response code from the server.  If the response code is needed,
+   use :meth:`descriptions`.
+
+   .. versionadded:: 2.4
+
+
+.. method:: NNTP.group(name)
+
+   Send a ``GROUP`` command, where *name* is the group name. Return a tuple
+   ``(response, count, first, last, name)`` where *count* is the (estimated) number
+   of articles in the group, *first* is the first article number in the group,
+   *last* is the last article number in the group, and *name* is the group name.
+   The numbers are returned as strings.
+
+
+.. method:: NNTP.help([file])
+
+   Send a ``HELP`` command.  Return a pair ``(response, list)`` where *list* is a
+   list of help strings. If the *file* parameter is supplied, then the output of
+   the  ``HELP`` command is stored in a file.  If *file* is a string,  then the
+   method will open a file object with that name, write to it  then close it.  If
+   *file* is a file object, then it will start calling :meth:`write` on it to store
+   the lines of the command output. If *file* is supplied, then the returned *list*
+   is an empty list.
+
+
+.. method:: NNTP.stat(id)
+
+   Send a ``STAT`` command, where *id* is the message id (enclosed in ``'<'`` and
+   ``'>'``) or an article number (as a string). Return a triple ``(response,
+   number, id)`` where *number* is the article number (as a string) and *id* is the
+   message id  (enclosed in ``'<'`` and ``'>'``).
+
+
+.. method:: NNTP.next()
+
+   Send a ``NEXT`` command.  Return as for :meth:`stat`.
+
+
+.. method:: NNTP.last()
+
+   Send a ``LAST`` command.  Return as for :meth:`stat`.
+
+
+.. method:: NNTP.head(id)
+
+   Send a ``HEAD`` command, where *id* has the same meaning as for :meth:`stat`.
+   Return a tuple ``(response, number, id, list)`` where the first three are the
+   same as for :meth:`stat`, and *list* is a list of the article's headers (an
+   uninterpreted list of lines, without trailing newlines).
+
+
+.. method:: NNTP.body(id,[file])
+
+   Send a ``BODY`` command, where *id* has the same meaning as for :meth:`stat`.
+   If the *file* parameter is supplied, then the body is stored in a file.  If
+   *file* is a string, then the method will open a file object with that name,
+   write to it then close it. If *file* is a file object, then it will start
+   calling :meth:`write` on it to store the lines of the body. Return as for
+   :meth:`head`.  If *file* is supplied, then the returned *list* is an empty list.
+
+
+.. method:: NNTP.article(id)
+
+   Send an ``ARTICLE`` command, where *id* has the same meaning as for
+   :meth:`stat`.  Return as for :meth:`head`.
+
+
+.. method:: NNTP.slave()
+
+   Send a ``SLAVE`` command.  Return the server's *response*.
+
+
+.. method:: NNTP.xhdr(header, string, [file])
+
+   Send an ``XHDR`` command.  This command is not defined in the RFC but is a
+   common extension.  The *header* argument is a header keyword, e.g.
+   ``'subject'``.  The *string* argument should have the form ``'first-last'``
+   where *first* and *last* are the first and last article numbers to search.
+   Return a pair ``(response, list)``, where *list* is a list of pairs ``(id,
+   text)``, where *id* is an article number (as a string) and *text* is the text of
+   the requested header for that article. If the *file* parameter is supplied, then
+   the output of the  ``XHDR`` command is stored in a file.  If *file* is a string,
+   then the method will open a file object with that name, write to it  then close
+   it.  If *file* is a file object, then it will start calling :meth:`write` on it
+   to store the lines of the command output. If *file* is supplied, then the
+   returned *list* is an empty list.
+
+
+.. method:: NNTP.post(file)
+
+   Post an article using the ``POST`` command.  The *file* argument is an open file
+   object which is read until EOF using its :meth:`readline` method.  It should be
+   a well-formed news article, including the required headers.  The :meth:`post`
+   method automatically escapes lines beginning with ``.``.
+
+
+.. method:: NNTP.ihave(id, file)
+
+   Send an ``IHAVE`` command. *id* is a message id (enclosed in  ``'<'`` and
+   ``'>'``). If the response is not an error, treat *file* exactly as for the
+   :meth:`post` method.
+
+
+.. method:: NNTP.date()
+
+   Return a triple ``(response, date, time)``, containing the current date and time
+   in a form suitable for the :meth:`newnews` and :meth:`newgroups` methods. This
+   is an optional NNTP extension, and may not be supported by all servers.
+
+
+.. method:: NNTP.xgtitle(name, [file])
+
+   Process an ``XGTITLE`` command, returning a pair ``(response, list)``, where
+   *list* is a list of tuples containing ``(name, title)``. If the *file* parameter
+   is supplied, then the output of the  ``XGTITLE`` command is stored in a file.
+   If *file* is a string,  then the method will open a file object with that name,
+   write to it  then close it.  If *file* is a file object, then it will start
+   calling :meth:`write` on it to store the lines of the command output. If *file*
+   is supplied, then the returned *list* is an empty list. This is an optional NNTP
+   extension, and may not be supported by all servers.
+
+   .. % XXX huh?  Should that be name, description?
+
+   RFC2980 says "It is suggested that this extension be deprecated".  Use
+   :meth:`descriptions` or :meth:`description` instead.
+
+
+.. method:: NNTP.xover(start, end, [file])
+
+   Return a pair ``(resp, list)``.  *list* is a list of tuples, one for each
+   article in the range delimited by the *start* and *end* article numbers.  Each
+   tuple is of the form ``(article number, subject, poster, date, id, references,
+   size, lines)``. If the *file* parameter is supplied, then the output of the
+   ``XOVER`` command is stored in a file.  If *file* is a string,  then the method
+   will open a file object with that name, write to it  then close it.  If *file*
+   is a file object, then it will start calling :meth:`write` on it to store the
+   lines of the command output. If *file* is supplied, then the returned *list* is
+   an empty list. This is an optional NNTP extension, and may not be supported by
+   all servers.
+
+
+.. method:: NNTP.xpath(id)
+
+   Return a pair ``(resp, path)``, where *path* is the directory path to the
+   article with message ID *id*.  This is an optional NNTP extension, and may not
+   be supported by all servers.
+
+
+.. method:: NNTP.quit()
+
+   Send a ``QUIT`` command and close the connection.  Once this method has been
+   called, no other methods of the NNTP object should be called.
+
diff --git a/Doc/library/numeric.rst b/Doc/library/numeric.rst
new file mode 100644
index 0000000..0d9d59f
--- /dev/null
+++ b/Doc/library/numeric.rst
@@ -0,0 +1,25 @@
+
+.. _numeric:
+
+********************************
+Numeric and Mathematical Modules
+********************************
+
+The modules described in this chapter provide numeric and math-related functions
+and data types. The :mod:`math` and :mod:`cmath` contain  various mathematical
+functions for floating-point and complex numbers. For users more interested in
+decimal accuracy than in speed, the  :mod:`decimal` module supports exact
+representations of  decimal numbers.
+
+The following modules are documented in this chapter:
+
+
+.. toctree::
+
+   math.rst
+   cmath.rst
+   decimal.rst
+   random.rst
+   itertools.rst
+   functools.rst
+   operator.rst
diff --git a/Doc/library/objects.rst b/Doc/library/objects.rst
new file mode 100644
index 0000000..c6cc9e4
--- /dev/null
+++ b/Doc/library/objects.rst
@@ -0,0 +1,32 @@
+
+.. _builtin:
+
+****************
+Built-in Objects
+****************
+
+.. index::
+   pair: built-in; types
+   pair: built-in; exceptions
+   pair: built-in; functions
+   pair: built-in; constants
+   single: symbol table
+
+Names for built-in exceptions and functions and a number of constants are found
+in a separate  symbol table.  This table is searched last when the interpreter
+looks up the meaning of a name, so local and global user-defined names can
+override built-in names.  Built-in types are described together here for easy
+reference. [#]_
+
+The tables in this chapter document the priorities of operators by listing them
+in order of ascending priority (within a table) and grouping operators that have
+the same priority in the same box. Binary operators of the same priority group
+from left to right. (Unary operators group from right to left, but there you
+have no real choice.)  See :ref:`operator-summary` for the complete picture on
+operator priorities.
+
+.. rubric:: Footnotes
+
+.. [#] Most descriptions sorely lack explanations of the exceptions that may be raised
+   --- this will be fixed in a future version of this manual.
+
diff --git a/Doc/library/operator.rst b/Doc/library/operator.rst
new file mode 100644
index 0000000..4e85569
--- /dev/null
+++ b/Doc/library/operator.rst
@@ -0,0 +1,612 @@
+:mod:`operator` --- Standard operators as functions
+===================================================
+
+.. module:: operator
+   :synopsis: Functions corresponding to the standard operators.
+.. sectionauthor:: Skip Montanaro 
+
+
+
+The :mod:`operator` module exports a set of functions implemented in C
+corresponding to the intrinsic operators of Python.  For example,
+``operator.add(x, y)`` is equivalent to the expression ``x+y``.  The function
+names are those used for special class methods; variants without leading and
+trailing ``__`` are also provided for convenience.
+
+The functions fall into categories that perform object comparisons, logical
+operations, mathematical operations, sequence operations, and abstract type
+tests.
+
+The object comparison functions are useful for all objects, and are named after
+the rich comparison operators they support:
+
+
+.. function:: lt(a, b)
+              le(a, b)
+              eq(a, b)
+              ne(a, b)
+              ge(a, b)
+              gt(a, b)
+              __lt__(a, b)
+              __le__(a, b)
+              __eq__(a, b)
+              __ne__(a, b)
+              __ge__(a, b)
+              __gt__(a, b)
+
+   Perform "rich comparisons" between *a* and *b*. Specifically, ``lt(a, b)`` is
+   equivalent to ``a < b``, ``le(a, b)`` is equivalent to ``a <= b``, ``eq(a,
+   b)`` is equivalent to ``a == b``, ``ne(a, b)`` is equivalent to ``a != b``,
+   ``gt(a, b)`` is equivalent to ``a > b`` and ``ge(a, b)`` is equivalent to ``a
+   >= b``.  Note that unlike the built-in :func:`cmp`, these functions can
+   return any value, which may or may not be interpretable as a Boolean value.
+   See :ref:`comparisons` for more information about rich comparisons.
+
+   .. versionadded:: 2.2
+
+The logical operations are also generally applicable to all objects, and support
+truth tests, identity tests, and boolean operations:
+
+
+.. function:: not_(o)
+              __not__(o)
+
+   Return the outcome of :keyword:`not` *o*.  (Note that there is no
+   :meth:`__not__` method for object instances; only the interpreter core defines
+   this operation.  The result is affected by the :meth:`__bool__` and
+   :meth:`__len__` methods.)
+
+
+.. function:: truth(o)
+
+   Return :const:`True` if *o* is true, and :const:`False` otherwise.  This is
+   equivalent to using the :class:`bool` constructor.
+
+
+.. function:: is_(a, b)
+
+   Return ``a is b``.  Tests object identity.
+
+   .. versionadded:: 2.3
+
+
+.. function:: is_not(a, b)
+
+   Return ``a is not b``.  Tests object identity.
+
+   .. versionadded:: 2.3
+
+The mathematical and bitwise operations are the most numerous:
+
+
+.. function:: abs(o)
+              __abs__(o)
+
+   Return the absolute value of *o*.
+
+
+.. function:: add(a, b)
+              __add__(a, b)
+
+   Return ``a + b``, for *a* and *b* numbers.
+
+
+.. function:: and_(a, b)
+              __and__(a, b)
+
+   Return the bitwise and of *a* and *b*.
+
+
+.. function:: div(a, b)
+              __div__(a, b)
+
+   Return ``a / b`` when ``__future__.division`` is not in effect.  This is
+   also known as "classic" division.
+
+
+.. function:: floordiv(a, b)
+              __floordiv__(a, b)
+
+   Return ``a // b``.
+
+   .. versionadded:: 2.2
+
+
+.. function:: inv(o)
+              invert(o)
+              __inv__(o)
+              __invert__(o)
+
+   Return the bitwise inverse of the number *o*.  This is equivalent to ``~o``.
+
+   .. versionadded:: 2.0
+      The names :func:`invert` and :func:`__invert__`.
+
+
+.. function:: lshift(a, b)
+              __lshift__(a, b)
+
+   Return *a* shifted left by *b*.
+
+
+.. function:: mod(a, b)
+              __mod__(a, b)
+
+   Return ``a % b``.
+
+
+.. function:: mul(a, b)
+              __mul__(a, b)
+
+   Return ``a * b``, for *a* and *b* numbers.
+
+
+.. function:: neg(o)
+              __neg__(o)
+
+   Return *o* negated.
+
+
+.. function:: or_(a, b)
+              __or__(a, b)
+
+   Return the bitwise or of *a* and *b*.
+
+
+.. function:: pos(o)
+              __pos__(o)
+
+   Return *o* positive.
+
+
+.. function:: pow(a, b)
+              __pow__(a, b)
+
+   Return ``a ** b``, for *a* and *b* numbers.
+
+   .. versionadded:: 2.3
+
+
+.. function:: rshift(a, b)
+              __rshift__(a, b)
+
+   Return *a* shifted right by *b*.
+
+
+.. function:: sub(a, b)
+              __sub__(a, b)
+
+   Return ``a - b``.
+
+
+.. function:: truediv(a, b)
+              __truediv__(a, b)
+
+   Return ``a / b`` when ``__future__.division`` is in effect.  This is also
+   known as "true" division.
+
+   .. versionadded:: 2.2
+
+
+.. function:: xor(a, b)
+              __xor__(a, b)
+
+   Return the bitwise exclusive or of *a* and *b*.
+
+
+.. function:: index(a)
+              __index__(a)
+
+   Return *a* converted to an integer.  Equivalent to ``a.__index__()``.
+
+   .. versionadded:: 2.5
+
+
+Operations which work with sequences include:
+
+.. function:: concat(a, b)
+              __concat__(a, b)
+
+   Return ``a + b`` for *a* and *b* sequences.
+
+
+.. function:: contains(a, b)
+              __contains__(a, b)
+
+   Return the outcome of the test ``b in a``. Note the reversed operands.
+
+   .. versionadded:: 2.0
+      The name :func:`__contains__`.
+
+
+.. function:: countOf(a, b)
+
+   Return the number of occurrences of *b* in *a*.
+
+
+.. function:: delitem(a, b)
+              __delitem__(a, b)
+
+   Remove the value of *a* at index *b*.
+
+
+.. function:: delslice(a, b, c)
+              __delslice__(a, b, c)
+
+   Delete the slice of *a* from index *b* to index *c-1*.
+
+
+.. function:: getitem(a, b)
+              __getitem__(a, b)
+
+   Return the value of *a* at index *b*.
+
+
+.. function:: getslice(a, b, c)
+              __getslice__(a, b, c)
+
+   Return the slice of *a* from index *b* to index *c-1*.
+
+
+.. function:: indexOf(a, b)
+
+   Return the index of the first of occurrence of *b* in *a*.
+
+
+.. function:: repeat(a, b)
+              __repeat__(a, b)
+
+   Return ``a * b`` where *a* is a sequence and *b* is an integer.
+
+
+.. function:: sequenceIncludes(...)
+
+   .. deprecated:: 2.0
+      Use :func:`contains` instead.
+
+   Alias for :func:`contains`.
+
+
+.. function:: setitem(a, b, c)
+              __setitem__(a, b, c)
+
+   Set the value of *a* at index *b* to *c*.
+
+
+.. function:: setslice(a, b, c, v)
+              __setslice__(a, b, c, v)
+
+   Set the slice of *a* from index *b* to index *c-1* to the sequence *v*.
+
+Many operations have an "in-place" version.  The following functions provide a
+more primitive access to in-place operators than the usual syntax does; for
+example, the statement ``x += y`` is equivalent to ``x = operator.iadd(x, y)``.
+Another way to put it is to say that ``z = operator.iadd(x, y)`` is equivalent
+to the compound statement ``z = x; z += y``.
+
+
+.. function:: iadd(a, b)
+              __iadd__(a, b)
+
+   ``a = iadd(a, b)`` is equivalent to ``a += b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: iand(a, b)
+              __iand__(a, b)
+
+   ``a = iand(a, b)`` is equivalent to ``a &= b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: iconcat(a, b)
+              __iconcat__(a, b)
+
+   ``a = iconcat(a, b)`` is equivalent to ``a += b`` for *a* and *b* sequences.
+
+   .. versionadded:: 2.5
+
+
+.. function:: idiv(a, b)
+              __idiv__(a, b)
+
+   ``a = idiv(a, b)`` is equivalent to ``a /= b`` when ``__future__.division`` is
+   not in effect.
+
+   .. versionadded:: 2.5
+
+
+.. function:: ifloordiv(a, b)
+              __ifloordiv__(a, b)
+
+   ``a = ifloordiv(a, b)`` is equivalent to ``a //= b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: ilshift(a, b)
+              __ilshift__(a, b)
+
+   ``a = ilshift(a, b)`` is equivalent to ``a <``\ ``<= b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: imod(a, b)
+              __imod__(a, b)
+
+   ``a = imod(a, b)`` is equivalent to ``a %= b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: imul(a, b)
+              __imul__(a, b)
+
+   ``a = imul(a, b)`` is equivalent to ``a *= b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: ior(a, b)
+              __ior__(a, b)
+
+   ``a = ior(a, b)`` is equivalent to ``a |= b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: ipow(a, b)
+              __ipow__(a, b)
+
+   ``a = ipow(a, b)`` is equivalent to ``a **= b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: irepeat(a, b)
+              __irepeat__(a, b)
+
+   ``a = irepeat(a, b)`` is equivalent to ``a *= b`` where *a* is a sequence and
+   *b* is an integer.
+
+   .. versionadded:: 2.5
+
+
+.. function:: irshift(a, b)
+              __irshift__(a, b)
+
+   ``a = irshift(a, b)`` is equivalent to ``a >>= b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: isub(a, b)
+              __isub__(a, b)
+
+   ``a = isub(a, b)`` is equivalent to ``a -= b``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: itruediv(a, b)
+              __itruediv__(a, b)
+
+   ``a = itruediv(a, b)`` is equivalent to ``a /= b`` when ``__future__.division``
+   is in effect.
+
+   .. versionadded:: 2.5
+
+
+.. function:: ixor(a, b)
+              __ixor__(a, b)
+
+   ``a = ixor(a, b)`` is equivalent to ``a ^= b``.
+
+   .. versionadded:: 2.5
+
+
+The :mod:`operator` module also defines a few predicates to test the type of
+objects.
+
+.. note::
+
+   Be careful not to misinterpret the results of these functions; only
+   :func:`isCallable` has any measure of reliability with instance objects.
+   For example::
+
+      >>> class C:
+      ...     pass
+      ... 
+      >>> import operator
+      >>> o = C()
+      >>> operator.isMappingType(o)
+      True
+
+
+.. function:: isCallable(o)
+
+   .. deprecated:: 2.0
+      Use the :func:`callable` built-in function instead.
+
+   Returns true if the object *o* can be called like a function, otherwise it
+   returns false.  True is returned for functions, bound and unbound methods, class
+   objects, and instance objects which support the :meth:`__call__` method.
+
+
+.. function:: isMappingType(o)
+
+   Returns true if the object *o* supports the mapping interface. This is true for
+   dictionaries and all instance objects defining :meth:`__getitem__`.
+
+   .. warning::
+
+      There is no reliable way to test if an instance supports the complete mapping
+      protocol since the interface itself is ill-defined.  This makes this test less
+      useful than it otherwise might be.
+
+
+.. function:: isNumberType(o)
+
+   Returns true if the object *o* represents a number.  This is true for all
+   numeric types implemented in C.
+
+   .. warning::
+
+      There is no reliable way to test if an instance supports the complete numeric
+      interface since the interface itself is ill-defined.  This makes this test less
+      useful than it otherwise might be.
+
+
+.. function:: isSequenceType(o)
+
+   Returns true if the object *o* supports the sequence protocol. This returns true
+   for all objects which define sequence methods in C, and for all instance objects
+   defining :meth:`__getitem__`.
+
+   .. warning::
+
+      There is no reliable way to test if an instance supports the complete sequence
+      interface since the interface itself is ill-defined.  This makes this test less
+      useful than it otherwise might be.
+
+Example: Build a dictionary that maps the ordinals from ``0`` to ``255`` to
+their character equivalents. ::
+
+   >>> import operator
+   >>> d = {}
+   >>> keys = range(256)
+   >>> vals = map(chr, keys)
+   >>> map(operator.setitem, [d]*len(keys), keys, vals)
+
+.. XXX: find a better, readable, example
+
+The :mod:`operator` module also defines tools for generalized attribute and item
+lookups.  These are useful for making fast field extractors as arguments for
+:func:`map`, :func:`sorted`, :meth:`itertools.groupby`, or other functions that
+expect a function argument.
+
+
+.. function:: attrgetter(attr[, args...])
+
+   Return a callable object that fetches *attr* from its operand. If more than one
+   attribute is requested, returns a tuple of attributes. After,
+   ``f=attrgetter('name')``, the call ``f(b)`` returns ``b.name``.  After,
+   ``f=attrgetter('name', 'date')``, the call ``f(b)`` returns ``(b.name,
+   b.date)``.
+
+   .. versionadded:: 2.4
+
+   .. versionchanged:: 2.5
+      Added support for multiple attributes.
+
+
+.. function:: itemgetter(item[, args...])
+
+   Return a callable object that fetches *item* from its operand. If more than one
+   item is requested, returns a tuple of items. After, ``f=itemgetter(2)``, the
+   call ``f(b)`` returns ``b[2]``. After, ``f=itemgetter(2,5,3)``, the call
+   ``f(b)`` returns ``(b[2], b[5], b[3])``.
+
+   .. versionadded:: 2.4
+
+   .. versionchanged:: 2.5
+      Added support for multiple item extraction.
+
+Examples::
+
+   >>> from operator import itemgetter
+   >>> inventory = [('apple', 3), ('banana', 2), ('pear', 5), ('orange', 1)]
+   >>> getcount = itemgetter(1)
+   >>> map(getcount, inventory)
+   [3, 2, 5, 1]
+   >>> sorted(inventory, key=getcount)
+   [('orange', 1), ('banana', 2), ('apple', 3), ('pear', 5)]
+
+
+.. _operator-map:
+
+Mapping Operators to Functions
+------------------------------
+
+This table shows how abstract operations correspond to operator symbols in the
+Python syntax and the functions in the :mod:`operator` module.
+
++-----------------------+-------------------------+---------------------------------+
+| Operation             | Syntax                  | Function                        |
++=======================+=========================+=================================+
+| Addition              | ``a + b``               | ``add(a, b)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Concatenation         | ``seq1 + seq2``         | ``concat(seq1, seq2)``          |
++-----------------------+-------------------------+---------------------------------+
+| Containment Test      | ``o in seq``            | ``contains(seq, o)``            |
++-----------------------+-------------------------+---------------------------------+
+| Division              | ``a / b``               | ``div(a, b)`` (without          |
+|                       |                         | ``__future__.division``)        |
++-----------------------+-------------------------+---------------------------------+
+| Division              | ``a / b``               | ``truediv(a, b)`` (with         |
+|                       |                         | ``__future__.division``)        |
++-----------------------+-------------------------+---------------------------------+
+| Division              | ``a // b``              | ``floordiv(a, b)``              |
++-----------------------+-------------------------+---------------------------------+
+| Bitwise And           | ``a & b``               | ``and_(a, b)``                  |
++-----------------------+-------------------------+---------------------------------+
+| Bitwise Exclusive Or  | ``a ^ b``               | ``xor(a, b)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Bitwise Inversion     | ``~ a``                 | ``invert(a)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Bitwise Or            | ``a | b``               | ``or_(a, b)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Exponentiation        | ``a ** b``              | ``pow(a, b)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Identity              | ``a is b``              | ``is_(a, b)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Identity              | ``a is not b``          | ``is_not(a, b)``                |
++-----------------------+-------------------------+---------------------------------+
+| Indexed Assignment    | ``o[k] = v``            | ``setitem(o, k, v)``            |
++-----------------------+-------------------------+---------------------------------+
+| Indexed Deletion      | ``del o[k]``            | ``delitem(o, k)``               |
++-----------------------+-------------------------+---------------------------------+
+| Indexing              | ``o[k]``                | ``getitem(o, k)``               |
++-----------------------+-------------------------+---------------------------------+
+| Left Shift            | ``a << b``              | ``lshift(a, b)``                |
++-----------------------+-------------------------+---------------------------------+
+| Modulo                | ``a % b``               | ``mod(a, b)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Multiplication        | ``a * b``               | ``mul(a, b)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Negation (Arithmetic) | ``- a``                 | ``neg(a)``                      |
++-----------------------+-------------------------+---------------------------------+
+| Negation (Logical)    | ``not a``               | ``not_(a)``                     |
++-----------------------+-------------------------+---------------------------------+
+| Right Shift           | ``a >> b``              | ``rshift(a, b)``                |
++-----------------------+-------------------------+---------------------------------+
+| Sequence Repitition   | ``seq * i``             | ``repeat(seq, i)``              |
++-----------------------+-------------------------+---------------------------------+
+| Slice Assignment      | ``seq[i:j] = values``   | ``setslice(seq, i, j, values)`` |
++-----------------------+-------------------------+---------------------------------+
+| Slice Deletion        | ``del seq[i:j]``        | ``delslice(seq, i, j)``         |
++-----------------------+-------------------------+---------------------------------+
+| Slicing               | ``seq[i:j]``            | ``getslice(seq, i, j)``         |
++-----------------------+-------------------------+---------------------------------+
+| String Formatting     | ``s % o``               | ``mod(s, o)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Subtraction           | ``a - b``               | ``sub(a, b)``                   |
++-----------------------+-------------------------+---------------------------------+
+| Truth Test            | ``o``                   | ``truth(o)``                    |
++-----------------------+-------------------------+---------------------------------+
+| Ordering              | ``a < b``               | ``lt(a, b)``                    |
++-----------------------+-------------------------+---------------------------------+
+| Ordering              | ``a <= b``              | ``le(a, b)``                    |
++-----------------------+-------------------------+---------------------------------+
+| Equality              | ``a == b``              | ``eq(a, b)``                    |
++-----------------------+-------------------------+---------------------------------+
+| Difference            | ``a != b``              | ``ne(a, b)``                    |
++-----------------------+-------------------------+---------------------------------+
+| Ordering              | ``a >= b``              | ``ge(a, b)``                    |
++-----------------------+-------------------------+---------------------------------+
+| Ordering              | ``a > b``               | ``gt(a, b)``                    |
++-----------------------+-------------------------+---------------------------------+
+
diff --git a/Doc/library/optparse.rst b/Doc/library/optparse.rst
new file mode 100644
index 0000000..cfcd8a6
--- /dev/null
+++ b/Doc/library/optparse.rst
@@ -0,0 +1,1827 @@
+.. % THIS FILE IS AUTO-GENERATED!  DO NOT EDIT!
+.. % (Your changes will be lost the next time it is generated.)
+
+
+:mod:`optparse` --- More powerful command line option parser
+============================================================
+
+.. module:: optparse
+   :synopsis: More convenient, flexible, and powerful command-line parsing library.
+.. moduleauthor:: Greg Ward 
+
+
+.. versionadded:: 2.3
+
+.. sectionauthor:: Greg Ward 
+
+
+``optparse`` is a more convenient, flexible, and powerful library for parsing
+command-line options than ``getopt``.  ``optparse`` uses a more declarative
+style of command-line parsing: you create an instance of :class:`OptionParser`,
+populate it with options, and parse the command line. ``optparse`` allows users
+to specify options in the conventional GNU/POSIX syntax, and additionally
+generates usage and help messages for you.
+
+.. % An intro blurb used only when generating LaTeX docs for the Python
+.. % manual (based on README.txt).
+
+Here's an example of using ``optparse`` in a simple script::
+
+   from optparse import OptionParser
+   [...]
+   parser = OptionParser()
+   parser.add_option("-f", "--file", dest="filename",
+                     help="write report to FILE", metavar="FILE")
+   parser.add_option("-q", "--quiet",
+                     action="store_false", dest="verbose", default=True,
+                     help="don't print status messages to stdout")
+
+   (options, args) = parser.parse_args()
+
+With these few lines of code, users of your script can now do the "usual thing"
+on the command-line, for example::
+
+    --file=outfile -q
+
+As it parses the command line, ``optparse`` sets attributes of the ``options``
+object returned by :meth:`parse_args` based on user-supplied command-line
+values.  When :meth:`parse_args` returns from parsing this command line,
+``options.filename`` will be ``"outfile"`` and ``options.verbose`` will be
+``False``.  ``optparse`` supports both long and short options, allows short
+options to be merged together, and allows options to be associated with their
+arguments in a variety of ways.  Thus, the following command lines are all
+equivalent to the above example::
+
+    -f outfile --quiet
+    --quiet --file outfile
+    -q -foutfile
+    -qfoutfile
+
+Additionally, users can run one of  ::
+
+    -h
+    --help
+
+and ``optparse`` will print out a brief summary of your script's options::
+
+   usage:  [options]
+
+   options:
+     -h, --help            show this help message and exit
+     -f FILE, --file=FILE  write report to FILE
+     -q, --quiet           don't print status messages to stdout
+
+where the value of *yourscript* is determined at runtime (normally from
+``sys.argv[0]``).
+
+.. % $Id: intro.txt 413 2004-09-28 00:59:13Z greg $
+
+
+.. _optparse-background:
+
+Background
+----------
+
+:mod:`optparse` was explicitly designed to encourage the creation of programs
+with straightforward, conventional command-line interfaces.  To that end, it
+supports only the most common command-line syntax and semantics conventionally
+used under Unix.  If you are unfamiliar with these conventions, read this
+section to acquaint yourself with them.
+
+
+.. _optparse-terminology:
+
+Terminology
+^^^^^^^^^^^
+
+argument
+   a string entered on the command-line, and passed by the shell to ``execl()`` or
+   ``execv()``.  In Python, arguments are elements of ``sys.argv[1:]``
+   (``sys.argv[0]`` is the name of the program being executed).  Unix shells also
+   use the term "word".
+
+   It is occasionally desirable to substitute an argument list other than
+   ``sys.argv[1:]``, so you should read "argument" as "an element of
+   ``sys.argv[1:]``, or of some other list provided as a substitute for
+   ``sys.argv[1:]``".
+
+option   
+   an argument used to supply extra information to guide or customize the execution
+   of a program.  There are many different syntaxes for options; the traditional
+   Unix syntax is a hyphen ("-") followed by a single letter, e.g. ``"-x"`` or
+   ``"-F"``.  Also, traditional Unix syntax allows multiple options to be merged
+   into a single argument, e.g.  ``"-x -F"`` is equivalent to ``"-xF"``.  The GNU
+   project introduced ``"--"`` followed by a series of hyphen-separated words, e.g.
+   ``"--file"`` or ``"--dry-run"``.  These are the only two option syntaxes
+   provided by :mod:`optparse`.
+
+   Some other option syntaxes that the world has seen include:
+
+   * a hyphen followed by a few letters, e.g. ``"-pf"`` (this is *not* the same
+     as multiple options merged into a single argument)
+
+   * a hyphen followed by a whole word, e.g. ``"-file"`` (this is technically
+     equivalent to the previous syntax, but they aren't usually seen in the same
+     program)
+
+   * a plus sign followed by a single letter, or a few letters, or a word, e.g.
+     ``"+f"``, ``"+rgb"``
+
+   * a slash followed by a letter, or a few letters, or a word, e.g. ``"/f"``,
+     ``"/file"``
+
+   These option syntaxes are not supported by :mod:`optparse`, and they never will
+   be.  This is deliberate: the first three are non-standard on any environment,
+   and the last only makes sense if you're exclusively targeting VMS, MS-DOS,
+   and/or Windows.
+
+option argument
+   an argument that follows an option, is closely associated with that option, and
+   is consumed from the argument list when that option is. With :mod:`optparse`,
+   option arguments may either be in a separate argument from their option::
+
+      -f foo
+      --file foo
+
+   or included in the same argument::
+
+      -ffoo
+      --file=foo
+
+   Typically, a given option either takes an argument or it doesn't. Lots of people
+   want an "optional option arguments" feature, meaning that some options will take
+   an argument if they see it, and won't if they don't.  This is somewhat
+   controversial, because it makes parsing ambiguous: if ``"-a"`` takes an optional
+   argument and ``"-b"`` is another option entirely, how do we interpret ``"-ab"``?
+   Because of this ambiguity, :mod:`optparse` does not support this feature.
+
+positional argument
+   something leftover in the argument list after options have been parsed, i.e.
+   after options and their arguments have been parsed and removed from the argument
+   list.
+
+required option
+   an option that must be supplied on the command-line; note that the phrase
+   "required option" is self-contradictory in English.  :mod:`optparse` doesn't
+   prevent you from implementing required options, but doesn't give you much help
+   at it either.  See ``examples/required_1.py`` and ``examples/required_2.py`` in
+   the :mod:`optparse` source distribution for two ways to implement required
+   options with :mod:`optparse`.
+
+For example, consider this hypothetical command-line::
+
+   prog -v --report /tmp/report.txt foo bar
+
+``"-v"`` and ``"--report"`` are both options.  Assuming that :option:`--report`
+takes one argument, ``"/tmp/report.txt"`` is an option argument.  ``"foo"`` and
+``"bar"`` are positional arguments.
+
+
+.. _optparse-what-options-for:
+
+What are options for?
+^^^^^^^^^^^^^^^^^^^^^
+
+Options are used to provide extra information to tune or customize the execution
+of a program.  In case it wasn't clear, options are usually *optional*.  A
+program should be able to run just fine with no options whatsoever.  (Pick a
+random program from the Unix or GNU toolsets.  Can it run without any options at
+all and still make sense?  The main exceptions are ``find``, ``tar``, and
+``dd``\ ---all of which are mutant oddballs that have been rightly criticized
+for their non-standard syntax and confusing interfaces.)
+
+Lots of people want their programs to have "required options".  Think about it.
+If it's required, then it's *not optional*!  If there is a piece of information
+that your program absolutely requires in order to run successfully, that's what
+positional arguments are for.
+
+As an example of good command-line interface design, consider the humble ``cp``
+utility, for copying files.  It doesn't make much sense to try to copy files
+without supplying a destination and at least one source. Hence, ``cp`` fails if
+you run it with no arguments.  However, it has a flexible, useful syntax that
+does not require any options at all::
+
+   cp SOURCE DEST
+   cp SOURCE ... DEST-DIR
+
+You can get pretty far with just that.  Most ``cp`` implementations provide a
+bunch of options to tweak exactly how the files are copied: you can preserve
+mode and modification time, avoid following symlinks, ask before clobbering
+existing files, etc.  But none of this distracts from the core mission of
+``cp``, which is to copy either one file to another, or several files to another
+directory.
+
+
+.. _optparse-what-positional-arguments-for:
+
+What are positional arguments for?
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Positional arguments are for those pieces of information that your program
+absolutely, positively requires to run.
+
+A good user interface should have as few absolute requirements as possible.  If
+your program requires 17 distinct pieces of information in order to run
+successfully, it doesn't much matter *how* you get that information from the
+user---most people will give up and walk away before they successfully run the
+program.  This applies whether the user interface is a command-line, a
+configuration file, or a GUI: if you make that many demands on your users, most
+of them will simply give up.
+
+In short, try to minimize the amount of information that users are absolutely
+required to supply---use sensible defaults whenever possible.  Of course, you
+also want to make your programs reasonably flexible.  That's what options are
+for.  Again, it doesn't matter if they are entries in a config file, widgets in
+the "Preferences" dialog of a GUI, or command-line options---the more options
+you implement, the more flexible your program is, and the more complicated its
+implementation becomes.  Too much flexibility has drawbacks as well, of course;
+too many options can overwhelm users and make your code much harder to maintain.
+
+.. % $Id: tao.txt 413 2004-09-28 00:59:13Z greg $
+
+
+.. _optparse-tutorial:
+
+Tutorial
+--------
+
+While :mod:`optparse` is quite flexible and powerful, it's also straightforward
+to use in most cases.  This section covers the code patterns that are common to
+any :mod:`optparse`\ -based program.
+
+First, you need to import the OptionParser class; then, early in the main
+program, create an OptionParser instance::
+
+   from optparse import OptionParser
+   [...]
+   parser = OptionParser()
+
+Then you can start defining options.  The basic syntax is::
+
+   parser.add_option(opt_str, ...,
+                     attr=value, ...)
+
+Each option has one or more option strings, such as ``"-f"`` or ``"--file"``,
+and several option attributes that tell :mod:`optparse` what to expect and what
+to do when it encounters that option on the command line.
+
+Typically, each option will have one short option string and one long option
+string, e.g.::
+
+   parser.add_option("-f", "--file", ...)
+
+You're free to define as many short option strings and as many long option
+strings as you like (including zero), as long as there is at least one option
+string overall.
+
+The option strings passed to :meth:`add_option` are effectively labels for the
+option defined by that call.  For brevity, we will frequently refer to
+*encountering an option* on the command line; in reality, :mod:`optparse`
+encounters *option strings* and looks up options from them.
+
+Once all of your options are defined, instruct :mod:`optparse` to parse your
+program's command line::
+
+   (options, args) = parser.parse_args()
+
+(If you like, you can pass a custom argument list to :meth:`parse_args`, but
+that's rarely necessary: by default it uses ``sys.argv[1:]``.)
+
+:meth:`parse_args` returns two values:
+
+* ``options``, an object containing values for all of your options---e.g. if
+  ``"--file"`` takes a single string argument, then ``options.file`` will be the
+  filename supplied by the user, or ``None`` if the user did not supply that
+  option
+
+* ``args``, the list of positional arguments leftover after parsing options
+
+This tutorial section only covers the four most important option attributes:
+:attr:`action`, :attr:`type`, :attr:`dest` (destination), and :attr:`help`. Of
+these, :attr:`action` is the most fundamental.
+
+
+.. _optparse-understanding-option-actions:
+
+Understanding option actions
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Actions tell :mod:`optparse` what to do when it encounters an option on the
+command line.  There is a fixed set of actions hard-coded into :mod:`optparse`;
+adding new actions is an advanced topic covered in section
+:ref:`optparse-extending-optparse`. Most actions tell
+:mod:`optparse` to store a value in some variable---for example, take a string
+from the command line and store it in an attribute of ``options``.
+
+If you don't specify an option action, :mod:`optparse` defaults to ``store``.
+
+
+.. _optparse-store-action:
+
+The store action
+^^^^^^^^^^^^^^^^
+
+The most common option action is ``store``, which tells :mod:`optparse` to take
+the next argument (or the remainder of the current argument), ensure that it is
+of the correct type, and store it to your chosen destination.
+
+For example::
+
+   parser.add_option("-f", "--file",
+                     action="store", type="string", dest="filename")
+
+Now let's make up a fake command line and ask :mod:`optparse` to parse it::
+
+   args = ["-f", "foo.txt"]
+   (options, args) = parser.parse_args(args)
+
+When :mod:`optparse` sees the option string ``"-f"``, it consumes the next
+argument, ``"foo.txt"``, and stores it in ``options.filename``.  So, after this
+call to :meth:`parse_args`, ``options.filename`` is ``"foo.txt"``.
+
+Some other option types supported by :mod:`optparse` are ``int`` and ``float``.
+Here's an option that expects an integer argument::
+
+   parser.add_option("-n", type="int", dest="num")
+
+Note that this option has no long option string, which is perfectly acceptable.
+Also, there's no explicit action, since the default is ``store``.
+
+Let's parse another fake command-line.  This time, we'll jam the option argument
+right up against the option: since ``"-n42"`` (one argument) is equivalent to
+``"-n 42"`` (two arguments), the code  ::
+
+   (options, args) = parser.parse_args(["-n42"])
+   print options.num
+
+will print ``"42"``.
+
+If you don't specify a type, :mod:`optparse` assumes ``string``.  Combined with
+the fact that the default action is ``store``, that means our first example can
+be a lot shorter::
+
+   parser.add_option("-f", "--file", dest="filename")
+
+If you don't supply a destination, :mod:`optparse` figures out a sensible
+default from the option strings: if the first long option string is
+``"--foo-bar"``, then the default destination is ``foo_bar``.  If there are no
+long option strings, :mod:`optparse` looks at the first short option string: the
+default destination for ``"-f"`` is ``f``.
+
+:mod:`optparse` also includes built-in ``long`` and ``complex`` types.  Adding
+types is covered in section :ref:`optparse-extending-optparse`.
+
+
+.. _optparse-handling-boolean-options:
+
+Handling boolean (flag) options
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Flag options---set a variable to true or false when a particular option is seen
+---are quite common.  :mod:`optparse` supports them with two separate actions,
+``store_true`` and ``store_false``.  For example, you might have a ``verbose``
+flag that is turned on with ``"-v"`` and off with ``"-q"``::
+
+   parser.add_option("-v", action="store_true", dest="verbose")
+   parser.add_option("-q", action="store_false", dest="verbose")
+
+Here we have two different options with the same destination, which is perfectly
+OK.  (It just means you have to be a bit careful when setting default values---
+see below.)
+
+When :mod:`optparse` encounters ``"-v"`` on the command line, it sets
+``options.verbose`` to ``True``; when it encounters ``"-q"``,
+``options.verbose`` is set to ``False``.
+
+
+.. _optparse-other-actions:
+
+Other actions
+^^^^^^^^^^^^^
+
+Some other actions supported by :mod:`optparse` are:
+
+``store_const``
+   store a constant value
+
+``append``
+   append this option's argument to a list
+
+``count``
+   increment a counter by one
+
+``callback``
+   call a specified function
+
+These are covered in section :ref:`optparse-reference-guide`, Reference Guide
+and section :ref:`optparse-option-callbacks`.
+
+
+.. _optparse-default-values:
+
+Default values
+^^^^^^^^^^^^^^
+
+All of the above examples involve setting some variable (the "destination") when
+certain command-line options are seen.  What happens if those options are never
+seen?  Since we didn't supply any defaults, they are all set to ``None``.  This
+is usually fine, but sometimes you want more control.  :mod:`optparse` lets you
+supply a default value for each destination, which is assigned before the
+command line is parsed.
+
+First, consider the verbose/quiet example.  If we want :mod:`optparse` to set
+``verbose`` to ``True`` unless ``"-q"`` is seen, then we can do this::
+
+   parser.add_option("-v", action="store_true", dest="verbose", default=True)
+   parser.add_option("-q", action="store_false", dest="verbose")
+
+Since default values apply to the *destination* rather than to any particular
+option, and these two options happen to have the same destination, this is
+exactly equivalent::
+
+   parser.add_option("-v", action="store_true", dest="verbose")
+   parser.add_option("-q", action="store_false", dest="verbose", default=True)
+
+Consider this::
+
+   parser.add_option("-v", action="store_true", dest="verbose", default=False)
+   parser.add_option("-q", action="store_false", dest="verbose", default=True)
+
+Again, the default value for ``verbose`` will be ``True``: the last default
+value supplied for any particular destination is the one that counts.
+
+A clearer way to specify default values is the :meth:`set_defaults` method of
+OptionParser, which you can call at any time before calling :meth:`parse_args`::
+
+   parser.set_defaults(verbose=True)
+   parser.add_option(...)
+   (options, args) = parser.parse_args()
+
+As before, the last value specified for a given option destination is the one
+that counts.  For clarity, try to use one method or the other of setting default
+values, not both.
+
+
+.. _optparse-generating-help:
+
+Generating help
+^^^^^^^^^^^^^^^
+
+:mod:`optparse`'s ability to generate help and usage text automatically is
+useful for creating user-friendly command-line interfaces.  All you have to do
+is supply a :attr:`help` value for each option, and optionally a short usage
+message for your whole program.  Here's an OptionParser populated with
+user-friendly (documented) options::
+
+   usage = "usage: %prog [options] arg1 arg2"
+   parser = OptionParser(usage=usage)
+   parser.add_option("-v", "--verbose",
+                     action="store_true", dest="verbose", default=True,
+                     help="make lots of noise [default]")
+   parser.add_option("-q", "--quiet",
+                     action="store_false", dest="verbose", 
+                     help="be vewwy quiet (I'm hunting wabbits)")
+   parser.add_option("-f", "--filename",
+                     metavar="FILE", help="write output to FILE"),
+   parser.add_option("-m", "--mode",
+                     default="intermediate",
+                     help="interaction mode: novice, intermediate, "
+                          "or expert [default: %default]")
+
+If :mod:`optparse` encounters either ``"-h"`` or ``"--help"`` on the
+command-line, or if you just call :meth:`parser.print_help`, it prints the
+following to standard output::
+
+   usage:  [options] arg1 arg2
+
+   options:
+     -h, --help            show this help message and exit
+     -v, --verbose         make lots of noise [default]
+     -q, --quiet           be vewwy quiet (I'm hunting wabbits)
+     -f FILE, --filename=FILE
+                           write output to FILE
+     -m MODE, --mode=MODE  interaction mode: novice, intermediate, or
+                           expert [default: intermediate]
+
+(If the help output is triggered by a help option, :mod:`optparse` exits after
+printing the help text.)
+
+There's a lot going on here to help :mod:`optparse` generate the best possible
+help message:
+
+* the script defines its own usage message::
+
+     usage = "usage: %prog [options] arg1 arg2"
+
+  :mod:`optparse` expands ``"%prog"`` in the usage string to the name of the
+  current program, i.e. ``os.path.basename(sys.argv[0])``.  The expanded string is
+  then printed before the detailed option help.
+
+  If you don't supply a usage string, :mod:`optparse` uses a bland but sensible
+  default: ``"usage: %prog [options]"``, which is fine if your script doesn't take
+  any positional arguments.
+
+* every option defines a help string, and doesn't worry about line-wrapping---
+  :mod:`optparse` takes care of wrapping lines and making the help output look
+  good.
+
+* options that take a value indicate this fact in their automatically-generated
+  help message, e.g. for the "mode" option::
+
+     -m MODE, --mode=MODE
+
+  Here, "MODE" is called the meta-variable: it stands for the argument that the
+  user is expected to supply to :option:`-m`/:option:`--mode`.  By default,
+  :mod:`optparse` converts the destination variable name to uppercase and uses
+  that for the meta-variable.  Sometimes, that's not what you want---for example,
+  the :option:`--filename` option explicitly sets ``metavar="FILE"``, resulting in
+  this automatically-generated option description::
+
+     -f FILE, --filename=FILE
+
+  This is important for more than just saving space, though: the manually written
+  help text uses the meta-variable "FILE" to clue the user in that there's a
+  connection between the semi-formal syntax "-f FILE" and the informal semantic
+  description "write output to FILE". This is a simple but effective way to make
+  your help text a lot clearer and more useful for end users.
+
+* options that have a default value can include ``%default`` in the help
+  string---\ :mod:`optparse` will replace it with :func:`str` of the option's
+  default value.  If an option has no default value (or the default value is
+  ``None``), ``%default`` expands to ``none``.
+
+
+.. _optparse-printing-version-string:
+
+Printing a version string
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Similar to the brief usage string, :mod:`optparse` can also print a version
+string for your program.  You have to supply the string as the ``version``
+argument to OptionParser::
+
+   parser = OptionParser(usage="%prog [-f] [-q]", version="%prog 1.0")
+
+``"%prog"`` is expanded just like it is in ``usage``.  Apart from that,
+``version`` can contain anything you like.  When you supply it, :mod:`optparse`
+automatically adds a ``"--version"`` option to your parser. If it encounters
+this option on the command line, it expands your ``version`` string (by
+replacing ``"%prog"``), prints it to stdout, and exits.
+
+For example, if your script is called ``/usr/bin/foo``::
+
+   $ /usr/bin/foo --version
+   foo 1.0
+
+
+.. _optparse-how-optparse-handles-errors:
+
+How :mod:`optparse` handles errors
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+There are two broad classes of errors that :mod:`optparse` has to worry about:
+programmer errors and user errors.  Programmer errors are usually erroneous
+calls to ``parser.add_option()``, e.g. invalid option strings, unknown option
+attributes, missing option attributes, etc.  These are dealt with in the usual
+way: raise an exception (either ``optparse.OptionError`` or ``TypeError``) and
+let the program crash.
+
+Handling user errors is much more important, since they are guaranteed to happen
+no matter how stable your code is.  :mod:`optparse` can automatically detect
+some user errors, such as bad option arguments (passing ``"-n 4x"`` where
+:option:`-n` takes an integer argument), missing arguments (``"-n"`` at the end
+of the command line, where :option:`-n` takes an argument of any type).  Also,
+you can call ``parser.error()`` to signal an application-defined error
+condition::
+
+   (options, args) = parser.parse_args()
+   [...]
+   if options.a and options.b:
+       parser.error("options -a and -b are mutually exclusive")
+
+In either case, :mod:`optparse` handles the error the same way: it prints the
+program's usage message and an error message to standard error and exits with
+error status 2.
+
+Consider the first example above, where the user passes ``"4x"`` to an option
+that takes an integer::
+
+   $ /usr/bin/foo -n 4x
+   usage: foo [options]
+
+   foo: error: option -n: invalid integer value: '4x'
+
+Or, where the user fails to pass a value at all::
+
+   $ /usr/bin/foo -n
+   usage: foo [options]
+
+   foo: error: -n option requires an argument
+
+:mod:`optparse`\ -generated error messages take care always to mention the
+option involved in the error; be sure to do the same when calling
+``parser.error()`` from your application code.
+
+If :mod:`optparse`'s default error-handling behaviour does not suite your needs,
+you'll need to subclass OptionParser and override ``exit()`` and/or
+:meth:`error`.
+
+
+.. _optparse-putting-it-all-together:
+
+Putting it all together
+^^^^^^^^^^^^^^^^^^^^^^^
+
+Here's what :mod:`optparse`\ -based scripts usually look like::
+
+   from optparse import OptionParser
+   [...]
+   def main():
+       usage = "usage: %prog [options] arg"
+       parser = OptionParser(usage)
+       parser.add_option("-f", "--file", dest="filename",
+                         help="read data from FILENAME")
+       parser.add_option("-v", "--verbose",
+                         action="store_true", dest="verbose")
+       parser.add_option("-q", "--quiet",
+                         action="store_false", dest="verbose")
+       [...]
+       (options, args) = parser.parse_args()
+       if len(args) != 1:
+           parser.error("incorrect number of arguments")
+       if options.verbose:
+           print "reading %s..." % options.filename
+       [...]
+
+   if __name__ == "__main__":
+       main()
+
+.. % $Id: tutorial.txt 515 2006-06-10 15:37:45Z gward $
+
+
+.. _optparse-reference-guide:
+
+Reference Guide
+---------------
+
+
+.. _optparse-creating-parser:
+
+Creating the parser
+^^^^^^^^^^^^^^^^^^^
+
+The first step in using :mod:`optparse` is to create an OptionParser instance::
+
+   parser = OptionParser(...)
+
+The OptionParser constructor has no required arguments, but a number of optional
+keyword arguments.  You should always pass them as keyword arguments, i.e. do
+not rely on the order in which the arguments are declared.
+
+   ``usage`` (default: ``"%prog [options]"``)
+      The usage summary to print when your program is run incorrectly or with a help
+      option.  When :mod:`optparse` prints the usage string, it expands ``%prog`` to
+      ``os.path.basename(sys.argv[0])`` (or to ``prog`` if you passed that keyword
+      argument).  To suppress a usage message, pass the special value
+      ``optparse.SUPPRESS_USAGE``.
+
+   ``option_list`` (default: ``[]``)
+      A list of Option objects to populate the parser with.  The options in
+      ``option_list`` are added after any options in ``standard_option_list`` (a class
+      attribute that may be set by OptionParser subclasses), but before any version or
+      help options. Deprecated; use :meth:`add_option` after creating the parser
+      instead.
+
+   ``option_class`` (default: optparse.Option)
+      Class to use when adding options to the parser in :meth:`add_option`.
+
+   ``version`` (default: ``None``)
+      A version string to print when the user supplies a version option. If you supply
+      a true value for ``version``, :mod:`optparse` automatically adds a version
+      option with the single option string ``"--version"``.  The substring ``"%prog"``
+      is expanded the same as for ``usage``.
+
+   ``conflict_handler`` (default: ``"error"``)
+      Specifies what to do when options with conflicting option strings are added to
+      the parser; see section :ref:`optparse-conflicts-between-options`.
+
+   ``description`` (default: ``None``)
+      A paragraph of text giving a brief overview of your program.  :mod:`optparse`
+      reformats this paragraph to fit the current terminal width and prints it when
+      the user requests help (after ``usage``, but before the list of options).
+
+   ``formatter`` (default: a new IndentedHelpFormatter)
+      An instance of optparse.HelpFormatter that will be used for printing help text.
+      :mod:`optparse` provides two concrete classes for this purpose:
+      IndentedHelpFormatter and TitledHelpFormatter.
+
+   ``add_help_option`` (default: ``True``)
+      If true, :mod:`optparse` will add a help option (with option strings ``"-h"``
+      and ``"--help"``) to the parser.
+
+   ``prog``
+      The string to use when expanding ``"%prog"`` in ``usage`` and ``version``
+      instead of ``os.path.basename(sys.argv[0])``.
+
+
+
+.. _optparse-populating-parser:
+
+Populating the parser
+^^^^^^^^^^^^^^^^^^^^^
+
+There are several ways to populate the parser with options.  The preferred way
+is by using ``OptionParser.add_option()``, as shown in section
+:ref:`optparse-tutorial`.  :meth:`add_option` can be called in one of two ways:
+
+* pass it an Option instance (as returned by :func:`make_option`)
+
+* pass it any combination of positional and keyword arguments that are
+  acceptable to :func:`make_option` (i.e., to the Option constructor), and it will
+  create the Option instance for you
+
+The other alternative is to pass a list of pre-constructed Option instances to
+the OptionParser constructor, as in::
+
+   option_list = [
+       make_option("-f", "--filename",
+                   action="store", type="string", dest="filename"),
+       make_option("-q", "--quiet",
+                   action="store_false", dest="verbose"),
+       ]
+   parser = OptionParser(option_list=option_list)
+
+(:func:`make_option` is a factory function for creating Option instances;
+currently it is an alias for the Option constructor.  A future version of
+:mod:`optparse` may split Option into several classes, and :func:`make_option`
+will pick the right class to instantiate.  Do not instantiate Option directly.)
+
+
+.. _optparse-defining-options:
+
+Defining options
+^^^^^^^^^^^^^^^^
+
+Each Option instance represents a set of synonymous command-line option strings,
+e.g. :option:`-f` and :option:`--file`.  You can specify any number of short or
+long option strings, but you must specify at least one overall option string.
+
+The canonical way to create an Option instance is with the :meth:`add_option`
+method of :class:`OptionParser`::
+
+   parser.add_option(opt_str[, ...], attr=value, ...)
+
+To define an option with only a short option string::
+
+   parser.add_option("-f", attr=value, ...)
+
+And to define an option with only a long option string::
+
+   parser.add_option("--foo", attr=value, ...)
+
+The keyword arguments define attributes of the new Option object.  The most
+important option attribute is :attr:`action`, and it largely determines which
+other attributes are relevant or required.  If you pass irrelevant option
+attributes, or fail to pass required ones, :mod:`optparse` raises an OptionError
+exception explaining your mistake.
+
+An options's *action* determines what :mod:`optparse` does when it encounters
+this option on the command-line.  The standard option actions hard-coded into
+:mod:`optparse` are:
+
+``store``
+   store this option's argument (default)
+
+``store_const``
+   store a constant value
+
+``store_true``
+   store a true value
+
+``store_false``
+   store a false value
+
+``append``
+   append this option's argument to a list
+
+``append_const``
+   append a constant value to a list
+
+``count``
+   increment a counter by one
+
+``callback``
+   call a specified function
+
+:attr:`help`
+   print a usage message including all options and the documentation for them
+
+(If you don't supply an action, the default is ``store``.  For this action, you
+may also supply :attr:`type` and :attr:`dest` option attributes; see below.)
+
+As you can see, most actions involve storing or updating a value somewhere.
+:mod:`optparse` always creates a special object for this, conventionally called
+``options`` (it happens to be an instance of ``optparse.Values``).  Option
+arguments (and various other values) are stored as attributes of this object,
+according to the :attr:`dest` (destination) option attribute.
+
+For example, when you call  ::
+
+   parser.parse_args()
+
+one of the first things :mod:`optparse` does is create the ``options`` object::
+
+   options = Values()
+
+If one of the options in this parser is defined with  ::
+
+   parser.add_option("-f", "--file", action="store", type="string", dest="filename")
+
+and the command-line being parsed includes any of the following::
+
+   -ffoo
+   -f foo
+   --file=foo
+   --file foo
+
+then :mod:`optparse`, on seeing this option, will do the equivalent of  ::
+
+   options.filename = "foo"
+
+The :attr:`type` and :attr:`dest` option attributes are almost as important as
+:attr:`action`, but :attr:`action` is the only one that makes sense for *all*
+options.
+
+
+.. _optparse-standard-option-actions:
+
+Standard option actions
+^^^^^^^^^^^^^^^^^^^^^^^
+
+The various option actions all have slightly different requirements and effects.
+Most actions have several relevant option attributes which you may specify to
+guide :mod:`optparse`'s behaviour; a few have required attributes, which you
+must specify for any option using that action.
+
+* ``store`` [relevant: :attr:`type`, :attr:`dest`, ``nargs``, ``choices``]
+
+  The option must be followed by an argument, which is converted to a value
+  according to :attr:`type` and stored in :attr:`dest`.  If ``nargs`` > 1,
+  multiple arguments will be consumed from the command line; all will be converted
+  according to :attr:`type` and stored to :attr:`dest` as a tuple.  See the
+  "Option types" section below.
+
+  If ``choices`` is supplied (a list or tuple of strings), the type defaults to
+  ``choice``.
+
+  If :attr:`type` is not supplied, it defaults to ``string``.
+
+  If :attr:`dest` is not supplied, :mod:`optparse` derives a destination from the
+  first long option string (e.g., ``"--foo-bar"`` implies ``foo_bar``). If there
+  are no long option strings, :mod:`optparse` derives a destination from the first
+  short option string (e.g., ``"-f"`` implies ``f``).
+
+  Example::
+
+     parser.add_option("-f")
+     parser.add_option("-p", type="float", nargs=3, dest="point")
+
+  As it parses the command line  ::
+
+     -f foo.txt -p 1 -3.5 4 -fbar.txt
+
+  :mod:`optparse` will set  ::
+
+     options.f = "foo.txt"
+     options.point = (1.0, -3.5, 4.0)
+     options.f = "bar.txt"
+
+* ``store_const`` [required: ``const``; relevant: :attr:`dest`]
+
+  The value ``const`` is stored in :attr:`dest`.
+
+  Example::
+
+     parser.add_option("-q", "--quiet",
+                       action="store_const", const=0, dest="verbose")
+     parser.add_option("-v", "--verbose",
+                       action="store_const", const=1, dest="verbose")
+     parser.add_option("--noisy",
+                       action="store_const", const=2, dest="verbose")
+
+  If ``"--noisy"`` is seen, :mod:`optparse` will set  ::
+
+     options.verbose = 2
+
+* ``store_true`` [relevant: :attr:`dest`]
+
+  A special case of ``store_const`` that stores a true value to :attr:`dest`.
+
+* ``store_false`` [relevant: :attr:`dest`]
+
+  Like ``store_true``, but stores a false value.
+
+  Example::
+
+     parser.add_option("--clobber", action="store_true", dest="clobber")
+     parser.add_option("--no-clobber", action="store_false", dest="clobber")
+
+* ``append`` [relevant: :attr:`type`, :attr:`dest`, ``nargs``, ``choices``]
+
+  The option must be followed by an argument, which is appended to the list in
+  :attr:`dest`.  If no default value for :attr:`dest` is supplied, an empty list
+  is automatically created when :mod:`optparse` first encounters this option on
+  the command-line.  If ``nargs`` > 1, multiple arguments are consumed, and a
+  tuple of length ``nargs`` is appended to :attr:`dest`.
+
+  The defaults for :attr:`type` and :attr:`dest` are the same as for the ``store``
+  action.
+
+  Example::
+
+     parser.add_option("-t", "--tracks", action="append", type="int")
+
+  If ``"-t3"`` is seen on the command-line, :mod:`optparse` does the equivalent
+  of::
+
+     options.tracks = []
+     options.tracks.append(int("3"))
+
+  If, a little later on, ``"--tracks=4"`` is seen, it does::
+
+     options.tracks.append(int("4"))
+
+* ``append_const`` [required: ``const``; relevant: :attr:`dest`]
+
+  Like ``store_const``, but the value ``const`` is appended to :attr:`dest`; as
+  with ``append``, :attr:`dest` defaults to ``None``, and an an empty list is
+  automatically created the first time the option is encountered.
+
+* ``count`` [relevant: :attr:`dest`]
+
+  Increment the integer stored at :attr:`dest`.  If no default value is supplied,
+  :attr:`dest` is set to zero before being incremented the first time.
+
+  Example::
+
+     parser.add_option("-v", action="count", dest="verbosity")
+
+  The first time ``"-v"`` is seen on the command line, :mod:`optparse` does the
+  equivalent of::
+
+     options.verbosity = 0
+     options.verbosity += 1
+
+  Every subsequent occurrence of ``"-v"`` results in  ::
+
+     options.verbosity += 1
+
+* ``callback`` [required: ``callback``; relevant: :attr:`type`, ``nargs``,
+  ``callback_args``, ``callback_kwargs``]
+
+  Call the function specified by ``callback``, which is called as  ::
+
+     func(option, opt_str, value, parser, *args, **kwargs)
+
+  See section :ref:`optparse-option-callbacks` for more detail.
+
+* :attr:`help`
+
+  Prints a complete help message for all the options in the current option parser.
+  The help message is constructed from the ``usage`` string passed to
+  OptionParser's constructor and the :attr:`help` string passed to every option.
+
+  If no :attr:`help` string is supplied for an option, it will still be listed in
+  the help message.  To omit an option entirely, use the special value
+  ``optparse.SUPPRESS_HELP``.
+
+  :mod:`optparse` automatically adds a :attr:`help` option to all OptionParsers,
+  so you do not normally need to create one.
+
+  Example::
+
+     from optparse import OptionParser, SUPPRESS_HELP
+
+     parser = OptionParser()
+     parser.add_option("-h", "--help", action="help"),
+     parser.add_option("-v", action="store_true", dest="verbose",
+                       help="Be moderately verbose")
+     parser.add_option("--file", dest="filename",
+                       help="Input file to read data from"),
+     parser.add_option("--secret", help=SUPPRESS_HELP)
+
+  If :mod:`optparse` sees either ``"-h"`` or ``"--help"`` on the command line, it
+  will print something like the following help message to stdout (assuming
+  ``sys.argv[0]`` is ``"foo.py"``)::
+
+     usage: foo.py [options]
+
+     options:
+       -h, --help        Show this help message and exit
+       -v                Be moderately verbose
+       --file=FILENAME   Input file to read data from
+
+  After printing the help message, :mod:`optparse` terminates your process with
+  ``sys.exit(0)``.
+
+* ``version``
+
+  Prints the version number supplied to the OptionParser to stdout and exits.  The
+  version number is actually formatted and printed by the ``print_version()``
+  method of OptionParser.  Generally only relevant if the ``version`` argument is
+  supplied to the OptionParser constructor.  As with :attr:`help` options, you
+  will rarely create ``version`` options, since :mod:`optparse` automatically adds
+  them when needed.
+
+
+.. _optparse-option-attributes:
+
+Option attributes
+^^^^^^^^^^^^^^^^^
+
+The following option attributes may be passed as keyword arguments to
+``parser.add_option()``.  If you pass an option attribute that is not relevant
+to a particular option, or fail to pass a required option attribute,
+:mod:`optparse` raises OptionError.
+
+* :attr:`action` (default: ``"store"``)
+
+  Determines :mod:`optparse`'s behaviour when this option is seen on the command
+  line; the available options are documented above.
+
+* :attr:`type` (default: ``"string"``)
+
+  The argument type expected by this option (e.g., ``"string"`` or ``"int"``); the
+  available option types are documented below.
+
+* :attr:`dest` (default: derived from option strings)
+
+  If the option's action implies writing or modifying a value somewhere, this
+  tells :mod:`optparse` where to write it: :attr:`dest` names an attribute of the
+  ``options`` object that :mod:`optparse` builds as it parses the command line.
+
+* ``default`` (deprecated)
+
+  The value to use for this option's destination if the option is not seen on the
+  command line.  Deprecated; use ``parser.set_defaults()`` instead.
+
+* ``nargs`` (default: 1)
+
+  How many arguments of type :attr:`type` should be consumed when this option is
+  seen.  If > 1, :mod:`optparse` will store a tuple of values to :attr:`dest`.
+
+* ``const``
+
+  For actions that store a constant value, the constant value to store.
+
+* ``choices``
+
+  For options of type ``"choice"``, the list of strings the user may choose from.
+
+* ``callback``
+
+  For options with action ``"callback"``, the callable to call when this option
+  is seen.  See section :ref:`optparse-option-callbacks` for detail on the
+  arguments passed to ``callable``.
+
+* ``callback_args``, ``callback_kwargs``
+
+  Additional positional and keyword arguments to pass to ``callback`` after the
+  four standard callback arguments.
+
+* :attr:`help`
+
+  Help text to print for this option when listing all available options after the
+  user supplies a :attr:`help` option (such as ``"--help"``). If no help text is
+  supplied, the option will be listed without help text.  To hide this option, use
+  the special value ``SUPPRESS_HELP``.
+
+* ``metavar`` (default: derived from option strings)
+
+  Stand-in for the option argument(s) to use when printing help text. See section
+  :ref:`optparse-tutorial` for an example.
+
+
+.. _optparse-standard-option-types:
+
+Standard option types
+^^^^^^^^^^^^^^^^^^^^^
+
+:mod:`optparse` has six built-in option types: ``string``, ``int``, ``long``,
+``choice``, ``float`` and ``complex``.  If you need to add new option types, see
+section :ref:`optparse-extending-optparse`.
+
+Arguments to string options are not checked or converted in any way: the text on
+the command line is stored in the destination (or passed to the callback) as-is.
+
+Integer arguments (type ``int`` or ``long``) are parsed as follows:
+
+* if the number starts with ``0x``, it is parsed as a hexadecimal number
+
+* if the number starts with ``0``, it is parsed as an octal number
+
+* if the number starts with ``0b``, is is parsed as a binary number
+
+* otherwise, the number is parsed as a decimal number
+
+
+The conversion is done by calling either ``int()`` or ``long()`` with the
+appropriate base (2, 8, 10, or 16).  If this fails, so will :mod:`optparse`,
+although with a more useful error message.
+
+``float`` and ``complex`` option arguments are converted directly with
+``float()`` and ``complex()``, with similar error-handling.
+
+``choice`` options are a subtype of ``string`` options.  The ``choices`` option
+attribute (a sequence of strings) defines the set of allowed option arguments.
+``optparse.check_choice()`` compares user-supplied option arguments against this
+master list and raises OptionValueError if an invalid string is given.
+
+
+.. _optparse-parsing-arguments:
+
+Parsing arguments
+^^^^^^^^^^^^^^^^^
+
+The whole point of creating and populating an OptionParser is to call its
+:meth:`parse_args` method::
+
+   (options, args) = parser.parse_args(args=None, values=None)
+
+where the input parameters are
+
+``args``
+   the list of arguments to process (default: ``sys.argv[1:]``)
+
+``values``
+   object to store option arguments in (default: a new instance of optparse.Values)
+
+and the return values are
+
+``options``
+   the same object that was passed in as ``options``, or the optparse.Values
+   instance created by :mod:`optparse`
+
+``args``
+   the leftover positional arguments after all options have been processed
+
+The most common usage is to supply neither keyword argument.  If you supply
+``options``, it will be modified with repeated ``setattr()`` calls (roughly one
+for every option argument stored to an option destination) and returned by
+:meth:`parse_args`.
+
+If :meth:`parse_args` encounters any errors in the argument list, it calls the
+OptionParser's :meth:`error` method with an appropriate end-user error message.
+This ultimately terminates your process with an exit status of 2 (the
+traditional Unix exit status for command-line errors).
+
+
+.. _optparse-querying-manipulating-option-parser:
+
+Querying and manipulating your option parser
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Sometimes, it's useful to poke around your option parser and see what's there.
+OptionParser provides a couple of methods to help you out:
+
+``has_option(opt_str)``
+   Return true if the OptionParser has an option with  option string ``opt_str``
+   (e.g., ``"-q"`` or ``"--verbose"``).
+
+``get_option(opt_str)``
+   Returns the Option instance with the option string ``opt_str``, or ``None`` if
+   no options have that option string.
+
+``remove_option(opt_str)``
+   If the OptionParser has an option corresponding to ``opt_str``, that option is
+   removed.  If that option provided any other option strings, all of those option
+   strings become invalid. If ``opt_str`` does not occur in any option belonging to
+   this OptionParser, raises ValueError.
+
+
+.. _optparse-conflicts-between-options:
+
+Conflicts between options
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+If you're not careful, it's easy to define options with conflicting option
+strings::
+
+   parser.add_option("-n", "--dry-run", ...)
+   [...]
+   parser.add_option("-n", "--noisy", ...)
+
+(This is particularly true if you've defined your own OptionParser subclass with
+some standard options.)
+
+Every time you add an option, :mod:`optparse` checks for conflicts with existing
+options.  If it finds any, it invokes the current conflict-handling mechanism.
+You can set the conflict-handling mechanism either in the constructor::
+
+   parser = OptionParser(..., conflict_handler=handler)
+
+or with a separate call::
+
+   parser.set_conflict_handler(handler)
+
+The available conflict handlers are:
+
+   ``error`` (default)
+      assume option conflicts are a programming error and raise  OptionConflictError
+
+   ``resolve``
+      resolve option conflicts intelligently (see below)
+
+
+As an example, let's define an OptionParser that resolves conflicts
+intelligently and add conflicting options to it::
+
+   parser = OptionParser(conflict_handler="resolve")
+   parser.add_option("-n", "--dry-run", ..., help="do no harm")
+   parser.add_option("-n", "--noisy", ..., help="be noisy")
+
+At this point, :mod:`optparse` detects that a previously-added option is already
+using the ``"-n"`` option string.  Since ``conflict_handler`` is ``"resolve"``,
+it resolves the situation by removing ``"-n"`` from the earlier option's list of
+option strings.  Now ``"--dry-run"`` is the only way for the user to activate
+that option.  If the user asks for help, the help message will reflect that::
+
+   options:
+     --dry-run     do no harm
+     [...]
+     -n, --noisy   be noisy
+
+It's possible to whittle away the option strings for a previously-added option
+until there are none left, and the user has no way of invoking that option from
+the command-line.  In that case, :mod:`optparse` removes that option completely,
+so it doesn't show up in help text or anywhere else. Carrying on with our
+existing OptionParser::
+
+   parser.add_option("--dry-run", ..., help="new dry-run option")
+
+At this point, the original :option:`-n/--dry-run` option is no longer
+accessible, so :mod:`optparse` removes it, leaving this help text::
+
+   options:
+     [...]
+     -n, --noisy   be noisy
+     --dry-run     new dry-run option
+
+
+.. _optparse-cleanup:
+
+Cleanup
+^^^^^^^
+
+OptionParser instances have several cyclic references.  This should not be a
+problem for Python's garbage collector, but you may wish to break the cyclic
+references explicitly by calling ``destroy()`` on your OptionParser once you are
+done with it.  This is particularly useful in long-running applications where
+large object graphs are reachable from your OptionParser.
+
+
+.. _optparse-other-methods:
+
+Other methods
+^^^^^^^^^^^^^
+
+OptionParser supports several other public methods:
+
+* ``set_usage(usage)``
+
+  Set the usage string according to the rules described above for the ``usage``
+  constructor keyword argument.  Passing ``None`` sets the default usage string;
+  use ``SUPPRESS_USAGE`` to suppress a usage message.
+
+* ``enable_interspersed_args()``, ``disable_interspersed_args()``
+
+  Enable/disable positional arguments interspersed with options, similar to GNU
+  getopt (enabled by default).  For example, if ``"-a"`` and ``"-b"`` are both
+  simple options that take no arguments, :mod:`optparse` normally accepts this
+  syntax::
+
+     prog -a arg1 -b arg2
+
+  and treats it as equivalent to  ::
+
+     prog -a -b arg1 arg2
+
+  To disable this feature, call ``disable_interspersed_args()``.  This restores
+  traditional Unix syntax, where option parsing stops with the first non-option
+  argument.
+
+* ``set_defaults(dest=value, ...)``
+
+  Set default values for several option destinations at once.  Using
+  :meth:`set_defaults` is the preferred way to set default values for options,
+  since multiple options can share the same destination.  For example, if several
+  "mode" options all set the same destination, any one of them can set the
+  default, and the last one wins::
+
+     parser.add_option("--advanced", action="store_const",
+                       dest="mode", const="advanced",
+                       default="novice")    # overridden below
+     parser.add_option("--novice", action="store_const",
+                       dest="mode", const="novice",
+                       default="advanced")  # overrides above setting
+
+  To avoid this confusion, use :meth:`set_defaults`::
+
+     parser.set_defaults(mode="advanced")
+     parser.add_option("--advanced", action="store_const",
+                       dest="mode", const="advanced")
+     parser.add_option("--novice", action="store_const",
+                       dest="mode", const="novice")
+
+.. % $Id: reference.txt 519 2006-06-11 14:39:11Z gward $
+
+
+.. _optparse-option-callbacks:
+
+Option Callbacks
+----------------
+
+When :mod:`optparse`'s built-in actions and types aren't quite enough for your
+needs, you have two choices: extend :mod:`optparse` or define a callback option.
+Extending :mod:`optparse` is more general, but overkill for a lot of simple
+cases.  Quite often a simple callback is all you need.
+
+There are two steps to defining a callback option:
+
+* define the option itself using the ``callback`` action
+
+* write the callback; this is a function (or method) that takes at least four
+  arguments, as described below
+
+
+.. _optparse-defining-callback-option:
+
+Defining a callback option
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+As always, the easiest way to define a callback option is by using the
+``parser.add_option()`` method.  Apart from :attr:`action`, the only option
+attribute you must specify is ``callback``, the function to call::
+
+   parser.add_option("-c", action="callback", callback=my_callback)
+
+``callback`` is a function (or other callable object), so you must have already
+defined ``my_callback()`` when you create this callback option. In this simple
+case, :mod:`optparse` doesn't even know if :option:`-c` takes any arguments,
+which usually means that the option takes no arguments---the mere presence of
+:option:`-c` on the command-line is all it needs to know.  In some
+circumstances, though, you might want your callback to consume an arbitrary
+number of command-line arguments.  This is where writing callbacks gets tricky;
+it's covered later in this section.
+
+:mod:`optparse` always passes four particular arguments to your callback, and it
+will only pass additional arguments if you specify them via ``callback_args``
+and ``callback_kwargs``.  Thus, the minimal callback function signature is::
+
+   def my_callback(option, opt, value, parser):
+
+The four arguments to a callback are described below.
+
+There are several other option attributes that you can supply when you define a
+callback option:
+
+:attr:`type`
+   has its usual meaning: as with the ``store`` or ``append`` actions, it instructs
+   :mod:`optparse` to consume one argument and convert it to :attr:`type`.  Rather
+   than storing the converted value(s) anywhere, though, :mod:`optparse` passes it
+   to your callback function.
+
+``nargs``
+   also has its usual meaning: if it is supplied and > 1, :mod:`optparse` will
+   consume ``nargs`` arguments, each of which must be convertible to :attr:`type`.
+   It then passes a tuple of converted values to your callback.
+
+``callback_args``
+   a tuple of extra positional arguments to pass to the callback
+
+``callback_kwargs``
+   a dictionary of extra keyword arguments to pass to the callback
+
+
+.. _optparse-how-callbacks-called:
+
+How callbacks are called
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+All callbacks are called as follows::
+
+   func(option, opt_str, value, parser, *args, **kwargs)
+
+where
+
+``option``
+   is the Option instance that's calling the callback
+
+``opt_str``
+   is the option string seen on the command-line that's triggering the callback.
+   (If an abbreviated long option was used, ``opt_str`` will be the full, canonical
+   option string---e.g. if the user puts ``"--foo"`` on the command-line as an
+   abbreviation for ``"--foobar"``, then ``opt_str`` will be ``"--foobar"``.)
+
+``value``
+   is the argument to this option seen on the command-line.  :mod:`optparse` will
+   only expect an argument if :attr:`type` is set; the type of ``value`` will be
+   the type implied by the option's type.  If :attr:`type` for this option is
+   ``None`` (no argument expected), then ``value`` will be ``None``.  If ``nargs``
+   > 1, ``value`` will be a tuple of values of the appropriate type.
+
+``parser``
+   is the OptionParser instance driving the whole thing, mainly useful because you
+   can access some other interesting data through its instance attributes:
+
+   ``parser.largs``
+      the current list of leftover arguments, ie. arguments that have been consumed
+      but are neither options nor option arguments. Feel free to modify
+      ``parser.largs``, e.g. by adding more arguments to it.  (This list will become
+      ``args``, the second return value of :meth:`parse_args`.)
+
+   ``parser.rargs``
+      the current list of remaining arguments, ie. with ``opt_str`` and ``value`` (if
+      applicable) removed, and only the arguments following them still there.  Feel
+      free to modify ``parser.rargs``, e.g. by consuming more arguments.
+
+   ``parser.values``
+      the object where option values are by default stored (an instance of
+      optparse.OptionValues).  This lets callbacks use the same mechanism as the rest
+      of :mod:`optparse` for storing option values; you don't need to mess around with
+      globals or closures.  You can also access or modify the value(s) of any options
+      already encountered on the command-line.
+
+``args``
+   is a tuple of arbitrary positional arguments supplied via the ``callback_args``
+   option attribute.
+
+``kwargs``
+   is a dictionary of arbitrary keyword arguments supplied via ``callback_kwargs``.
+
+
+.. _optparse-raising-errors-in-callback:
+
+Raising errors in a callback
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The callback function should raise OptionValueError if there are any problems
+with the option or its argument(s).  :mod:`optparse` catches this and terminates
+the program, printing the error message you supply to stderr.  Your message
+should be clear, concise, accurate, and mention the option at fault.  Otherwise,
+the user will have a hard time figuring out what he did wrong.
+
+
+.. _optparse-callback-example-1:
+
+Callback example 1: trivial callback
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Here's an example of a callback option that takes no arguments, and simply
+records that the option was seen::
+
+   def record_foo_seen(option, opt_str, value, parser):
+       parser.saw_foo = True
+
+   parser.add_option("--foo", action="callback", callback=record_foo_seen)
+
+Of course, you could do that with the ``store_true`` action.
+
+
+.. _optparse-callback-example-2:
+
+Callback example 2: check option order
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Here's a slightly more interesting example: record the fact that ``"-a"`` is
+seen, but blow up if it comes after ``"-b"`` in the command-line.  ::
+
+   def check_order(option, opt_str, value, parser):
+       if parser.values.b:
+           raise OptionValueError("can't use -a after -b")
+       parser.values.a = 1
+   [...]
+   parser.add_option("-a", action="callback", callback=check_order)
+   parser.add_option("-b", action="store_true", dest="b")
+
+
+.. _optparse-callback-example-3:
+
+Callback example 3: check option order (generalized)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+If you want to re-use this callback for several similar options (set a flag, but
+blow up if ``"-b"`` has already been seen), it needs a bit of work: the error
+message and the flag that it sets must be generalized.  ::
+
+   def check_order(option, opt_str, value, parser):
+       if parser.values.b:
+           raise OptionValueError("can't use %s after -b" % opt_str)
+       setattr(parser.values, option.dest, 1)
+   [...]
+   parser.add_option("-a", action="callback", callback=check_order, dest='a')
+   parser.add_option("-b", action="store_true", dest="b")
+   parser.add_option("-c", action="callback", callback=check_order, dest='c')
+
+
+.. _optparse-callback-example-4:
+
+Callback example 4: check arbitrary condition
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Of course, you could put any condition in there---you're not limited to checking
+the values of already-defined options.  For example, if you have options that
+should not be called when the moon is full, all you have to do is this::
+
+   def check_moon(option, opt_str, value, parser):
+       if is_moon_full():
+           raise OptionValueError("%s option invalid when moon is full"
+                                  % opt_str)
+       setattr(parser.values, option.dest, 1)
+   [...]
+   parser.add_option("--foo",
+                     action="callback", callback=check_moon, dest="foo")
+
+(The definition of ``is_moon_full()`` is left as an exercise for the reader.)
+
+
+.. _optparse-callback-example-5:
+
+Callback example 5: fixed arguments
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Things get slightly more interesting when you define callback options that take
+a fixed number of arguments.  Specifying that a callback option takes arguments
+is similar to defining a ``store`` or ``append`` option: if you define
+:attr:`type`, then the option takes one argument that must be convertible to
+that type; if you further define ``nargs``, then the option takes ``nargs``
+arguments.
+
+Here's an example that just emulates the standard ``store`` action::
+
+   def store_value(option, opt_str, value, parser):
+       setattr(parser.values, option.dest, value)
+   [...]
+   parser.add_option("--foo",
+                     action="callback", callback=store_value,
+                     type="int", nargs=3, dest="foo")
+
+Note that :mod:`optparse` takes care of consuming 3 arguments and converting
+them to integers for you; all you have to do is store them.  (Or whatever;
+obviously you don't need a callback for this example.)
+
+
+.. _optparse-callback-example-6:
+
+Callback example 6: variable arguments
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Things get hairy when you want an option to take a variable number of arguments.
+For this case, you must write a callback, as :mod:`optparse` doesn't provide any
+built-in capabilities for it.  And you have to deal with certain intricacies of
+conventional Unix command-line parsing that :mod:`optparse` normally handles for
+you.  In particular, callbacks should implement the conventional rules for bare
+``"--"`` and ``"-"`` arguments:
+
+* either ``"--"`` or ``"-"`` can be option arguments
+
+* bare ``"--"`` (if not the argument to some option): halt command-line
+  processing and discard the ``"--"``
+
+* bare ``"-"`` (if not the argument to some option): halt command-line
+  processing but keep the ``"-"`` (append it to ``parser.largs``)
+
+If you want an option that takes a variable number of arguments, there are
+several subtle, tricky issues to worry about.  The exact implementation you
+choose will be based on which trade-offs you're willing to make for your
+application (which is why :mod:`optparse` doesn't support this sort of thing
+directly).
+
+Nevertheless, here's a stab at a callback for an option with variable
+arguments::
+
+   def vararg_callback(option, opt_str, value, parser):
+       assert value is None
+       done = 0
+       value = []
+       rargs = parser.rargs
+       while rargs:
+           arg = rargs[0]
+
+           # Stop if we hit an arg like "--foo", "-a", "-fx", "--file=f",
+           # etc.  Note that this also stops on "-3" or "-3.0", so if
+           # your option takes numeric values, you will need to handle
+           # this.
+           if ((arg[:2] == "--" and len(arg) > 2) or
+               (arg[:1] == "-" and len(arg) > 1 and arg[1] != "-")):
+               break
+           else:
+               value.append(arg)
+               del rargs[0]
+
+        setattr(parser.values, option.dest, value)
+
+   [...]
+   parser.add_option("-c", "--callback",
+                     action="callback", callback=varargs)
+
+The main weakness with this particular implementation is that negative numbers
+in the arguments following ``"-c"`` will be interpreted as further options
+(probably causing an error), rather than as arguments to ``"-c"``.  Fixing this
+is left as an exercise for the reader.
+
+.. % $Id: callbacks.txt 415 2004-09-30 02:26:17Z greg $
+
+
+.. _optparse-extending-optparse:
+
+Extending :mod:`optparse`
+-------------------------
+
+Since the two major controlling factors in how :mod:`optparse` interprets
+command-line options are the action and type of each option, the most likely
+direction of extension is to add new actions and new types.
+
+
+.. _optparse-adding-new-types:
+
+Adding new types
+^^^^^^^^^^^^^^^^
+
+To add new types, you need to define your own subclass of :mod:`optparse`'s
+Option class.  This class has a couple of attributes that define
+:mod:`optparse`'s types: :attr:`TYPES` and :attr:`TYPE_CHECKER`.
+
+:attr:`TYPES` is a tuple of type names; in your subclass, simply define a new
+tuple :attr:`TYPES` that builds on the standard one.
+
+:attr:`TYPE_CHECKER` is a dictionary mapping type names to type-checking
+functions.  A type-checking function has the following signature::
+
+   def check_mytype(option, opt, value)
+
+where ``option`` is an :class:`Option` instance, ``opt`` is an option string
+(e.g., ``"-f"``), and ``value`` is the string from the command line that must be
+checked and converted to your desired type.  ``check_mytype()`` should return an
+object of the hypothetical type ``mytype``.  The value returned by a
+type-checking function will wind up in the OptionValues instance returned by
+:meth:`OptionParser.parse_args`, or be passed to a callback as the ``value``
+parameter.
+
+Your type-checking function should raise OptionValueError if it encounters any
+problems.  OptionValueError takes a single string argument, which is passed
+as-is to OptionParser's :meth:`error` method, which in turn prepends the program
+name and the string ``"error:"`` and prints everything to stderr before
+terminating the process.
+
+Here's a silly example that demonstrates adding a ``complex`` option type to
+parse Python-style complex numbers on the command line.  (This is even sillier
+than it used to be, because :mod:`optparse` 1.3 added built-in support for
+complex numbers, but never mind.)
+
+First, the necessary imports::
+
+   from copy import copy
+   from optparse import Option, OptionValueError
+
+You need to define your type-checker first, since it's referred to later (in the
+:attr:`TYPE_CHECKER` class attribute of your Option subclass)::
+
+   def check_complex(option, opt, value):
+       try:
+           return complex(value)
+       except ValueError:
+           raise OptionValueError(
+               "option %s: invalid complex value: %r" % (opt, value))
+
+Finally, the Option subclass::
+
+   class MyOption (Option):
+       TYPES = Option.TYPES + ("complex",)
+       TYPE_CHECKER = copy(Option.TYPE_CHECKER)
+       TYPE_CHECKER["complex"] = check_complex
+
+(If we didn't make a :func:`copy` of :attr:`Option.TYPE_CHECKER`, we would end
+up modifying the :attr:`TYPE_CHECKER` attribute of :mod:`optparse`'s Option
+class. This being Python, nothing stops you from doing that except good manners
+and common sense.)
+
+That's it!  Now you can write a script that uses the new option type just like
+any other :mod:`optparse`\ -based script, except you have to instruct your
+OptionParser to use MyOption instead of Option::
+
+   parser = OptionParser(option_class=MyOption)
+   parser.add_option("-c", type="complex")
+
+Alternately, you can build your own option list and pass it to OptionParser; if
+you don't use :meth:`add_option` in the above way, you don't need to tell
+OptionParser which option class to use::
+
+   option_list = [MyOption("-c", action="store", type="complex", dest="c")]
+   parser = OptionParser(option_list=option_list)
+
+
+.. _optparse-adding-new-actions:
+
+Adding new actions
+^^^^^^^^^^^^^^^^^^
+
+Adding new actions is a bit trickier, because you have to understand that
+:mod:`optparse` has a couple of classifications for actions:
+
+"store" actions
+   actions that result in :mod:`optparse` storing a value to an attribute of the
+   current OptionValues instance; these options require a :attr:`dest` attribute to
+   be supplied to the Option constructor
+
+"typed" actions
+   actions that take a value from the command line and expect it to be of a certain
+   type; or rather, a string that can be converted to a certain type.  These
+   options require a :attr:`type` attribute to the Option constructor.
+
+These are overlapping sets: some default "store" actions are ``store``,
+``store_const``, ``append``, and ``count``, while the default "typed" actions
+are ``store``, ``append``, and ``callback``.
+
+When you add an action, you need to categorize it by listing it in at least one
+of the following class attributes of Option (all are lists of strings):
+
+:attr:`ACTIONS`
+   all actions must be listed in ACTIONS
+
+:attr:`STORE_ACTIONS`
+   "store" actions are additionally listed here
+
+:attr:`TYPED_ACTIONS`
+   "typed" actions are additionally listed here
+
+``ALWAYS_TYPED_ACTIONS``
+   actions that always take a type (i.e. whose options always take a value) are
+   additionally listed here.  The only effect of this is that :mod:`optparse`
+   assigns the default type, ``string``, to options with no explicit type whose
+   action is listed in ``ALWAYS_TYPED_ACTIONS``.
+
+In order to actually implement your new action, you must override Option's
+:meth:`take_action` method and add a case that recognizes your action.
+
+For example, let's add an ``extend`` action.  This is similar to the standard
+``append`` action, but instead of taking a single value from the command-line
+and appending it to an existing list, ``extend`` will take multiple values in a
+single comma-delimited string, and extend an existing list with them.  That is,
+if ``"--names"`` is an ``extend`` option of type ``string``, the command line
+::
+
+   --names=foo,bar --names blah --names ding,dong
+
+would result in a list  ::
+
+   ["foo", "bar", "blah", "ding", "dong"]
+
+Again we define a subclass of Option::
+
+   class MyOption (Option):
+
+       ACTIONS = Option.ACTIONS + ("extend",)
+       STORE_ACTIONS = Option.STORE_ACTIONS + ("extend",)
+       TYPED_ACTIONS = Option.TYPED_ACTIONS + ("extend",)
+       ALWAYS_TYPED_ACTIONS = Option.ALWAYS_TYPED_ACTIONS + ("extend",)
+
+       def take_action(self, action, dest, opt, value, values, parser):
+           if action == "extend":
+               lvalue = value.split(",")
+               values.ensure_value(dest, []).extend(lvalue)
+           else:
+               Option.take_action(
+                   self, action, dest, opt, value, values, parser)
+
+Features of note:
+
+* ``extend`` both expects a value on the command-line and stores that value
+  somewhere, so it goes in both :attr:`STORE_ACTIONS` and :attr:`TYPED_ACTIONS`
+
+* to ensure that :mod:`optparse` assigns the default type of ``string`` to
+  ``extend`` actions, we put the ``extend`` action in ``ALWAYS_TYPED_ACTIONS`` as
+  well
+
+* :meth:`MyOption.take_action` implements just this one new action, and passes
+  control back to :meth:`Option.take_action` for the standard :mod:`optparse`
+  actions
+
+* ``values`` is an instance of the optparse_parser.Values class, which
+  provides the very useful :meth:`ensure_value` method. :meth:`ensure_value` is
+  essentially :func:`getattr` with a safety valve; it is called as  ::
+
+     values.ensure_value(attr, value)
+
+  If the ``attr`` attribute of ``values`` doesn't exist or is None, then
+  ensure_value() first sets it to ``value``, and then returns 'value. This is very
+  handy for actions like ``extend``, ``append``, and ``count``, all of which
+  accumulate data in a variable and expect that variable to be of a certain type
+  (a list for the first two, an integer for the latter).  Using
+  :meth:`ensure_value` means that scripts using your action don't have to worry
+  about setting a default value for the option destinations in question; they can
+  just leave the default as None and :meth:`ensure_value` will take care of
+  getting it right when it's needed.
+
+.. % $Id: extending.txt 517 2006-06-10 16:18:11Z gward $
+
diff --git a/Doc/library/os.path.rst b/Doc/library/os.path.rst
new file mode 100644
index 0000000..291d155
--- /dev/null
+++ b/Doc/library/os.path.rst
@@ -0,0 +1,317 @@
+
+:mod:`os.path` --- Common pathname manipulations
+================================================
+
+.. module:: os.path
+   :synopsis: Operations on pathnames.
+
+
+.. index:: single: path; operations
+
+This module implements some useful functions on pathnames. To read or
+write files see :func:`open`, and for accessing the filesystem see the
+:mod:`os` module.
+
+.. warning::
+
+   On Windows, many of these functions do not properly support UNC pathnames.
+   :func:`splitunc` and :func:`ismount` do handle them correctly.
+
+
+.. function:: abspath(path)
+
+   Return a normalized absolutized version of the pathname *path*. On most
+   platforms, this is equivalent to ``normpath(join(os.getcwd(), path))``.
+
+   .. versionadded:: 1.5.2
+
+
+.. function:: basename(path)
+
+   Return the base name of pathname *path*.  This is the second half of the pair
+   returned by ``split(path)``.  Note that the result of this function is different
+   from the Unix :program:`basename` program; where :program:`basename` for
+   ``'/foo/bar/'`` returns ``'bar'``, the :func:`basename` function returns an
+   empty string (``''``).
+
+
+.. function:: commonprefix(list)
+
+   Return the longest path prefix (taken character-by-character) that is a prefix
+   of all paths in  *list*.  If *list* is empty, return the empty string (``''``).
+   Note that this may return invalid paths because it works a character at a time.
+
+
+.. function:: dirname(path)
+
+   Return the directory name of pathname *path*.  This is the first half of the
+   pair returned by ``split(path)``.
+
+
+.. function:: exists(path)
+
+   Return ``True`` if *path* refers to an existing path.  Returns ``False`` for
+   broken symbolic links. On some platforms, this function may return ``False`` if
+   permission is not granted to execute :func:`os.stat` on the requested file, even
+   if the *path* physically exists.
+
+
+.. function:: lexists(path)
+
+   Return ``True`` if *path* refers to an existing path. Returns ``True`` for
+   broken symbolic links.   Equivalent to :func:`exists` on platforms lacking
+   :func:`os.lstat`.
+
+   .. versionadded:: 2.4
+
+
+.. function:: expanduser(path)
+
+   On Unix and Windows, return the argument with an initial component of ``~`` or
+   ``~user`` replaced by that *user*'s home directory.
+
+   .. index:: module: pwd
+
+   On Unix, an initial ``~`` is replaced by the environment variable :envvar:`HOME`
+   if it is set; otherwise the current user's home directory is looked up in the
+   password directory through the built-in module :mod:`pwd`. An initial ``~user``
+   is looked up directly in the password directory.
+
+   On Windows, :envvar:`HOME` and :envvar:`USERPROFILE` will be used if set,
+   otherwise a combination of :envvar:`HOMEPATH` and :envvar:`HOMEDRIVE` will be
+   used.  An initial ``~user`` is handled by stripping the last directory component
+   from the created user path derived above.
+
+   If the expansion fails or if the path does not begin with a tilde, the path is
+   returned unchanged.
+
+
+.. function:: expandvars(path)
+
+   Return the argument with environment variables expanded.  Substrings of the form
+   ``$name`` or ``${name}`` are replaced by the value of environment variable
+   *name*.  Malformed variable names and references to non-existing variables are
+   left unchanged.
+
+   On Windows, ``%name%`` expansions are supported in addition to ``$name`` and
+   ``${name}``.
+
+
+.. function:: getatime(path)
+
+   Return the time of last access of *path*.  The return value is a number giving
+   the number of seconds since the epoch (see the  :mod:`time` module).  Raise
+   :exc:`os.error` if the file does not exist or is inaccessible.
+
+   .. versionadded:: 1.5.2
+
+   .. versionchanged:: 2.3
+      If :func:`os.stat_float_times` returns True, the result is a floating point
+      number.
+
+
+.. function:: getmtime(path)
+
+   Return the time of last modification of *path*.  The return value is a number
+   giving the number of seconds since the epoch (see the  :mod:`time` module).
+   Raise :exc:`os.error` if the file does not exist or is inaccessible.
+
+   .. versionadded:: 1.5.2
+
+   .. versionchanged:: 2.3
+      If :func:`os.stat_float_times` returns True, the result is a floating point
+      number.
+
+
+.. function:: getctime(path)
+
+   Return the system's ctime which, on some systems (like Unix) is the time of the
+   last change, and, on others (like Windows), is the creation time for *path*.
+   The return value is a number giving the number of seconds since the epoch (see
+   the  :mod:`time` module).  Raise :exc:`os.error` if the file does not exist or
+   is inaccessible.
+
+   .. versionadded:: 2.3
+
+
+.. function:: getsize(path)
+
+   Return the size, in bytes, of *path*.  Raise :exc:`os.error` if the file does
+   not exist or is inaccessible.
+
+   .. versionadded:: 1.5.2
+
+
+.. function:: isabs(path)
+
+   Return ``True`` if *path* is an absolute pathname (begins with a slash).
+
+
+.. function:: isfile(path)
+
+   Return ``True`` if *path* is an existing regular file.  This follows symbolic
+   links, so both :func:`islink` and :func:`isfile` can be true for the same path.
+
+
+.. function:: isdir(path)
+
+   Return ``True`` if *path* is an existing directory.  This follows symbolic
+   links, so both :func:`islink` and :func:`isdir` can be true for the same path.
+
+
+.. function:: islink(path)
+
+   Return ``True`` if *path* refers to a directory entry that is a symbolic link.
+   Always ``False`` if symbolic links are not supported.
+
+
+.. function:: ismount(path)
+
+   Return ``True`` if pathname *path* is a :dfn:`mount point`: a point in a file
+   system where a different file system has been mounted.  The function checks
+   whether *path*'s parent, :file:`path/..`, is on a different device than *path*,
+   or whether :file:`path/..` and *path* point to the same i-node on the same
+   device --- this should detect mount points for all Unix and POSIX variants.
+
+
+.. function:: join(path1[, path2[, ...]])
+
+   Join one or more path components intelligently.  If any component is an absolute
+   path, all previous components (on Windows, including the previous drive letter,
+   if there was one) are thrown away, and joining continues.  The return value is
+   the concatenation of *path1*, and optionally *path2*, etc., with exactly one
+   directory separator (``os.sep``) inserted between components, unless *path2* is
+   empty.  Note that on Windows, since there is a current directory for each drive,
+   ``os.path.join("c:", "foo")`` represents a path relative to the current
+   directory on drive :file:`C:` (:file:`c:foo`), not :file:`c:\\foo`.
+
+
+.. function:: normcase(path)
+
+   Normalize the case of a pathname.  On Unix, this returns the path unchanged; on
+   case-insensitive filesystems, it converts the path to lowercase.  On Windows, it
+   also converts forward slashes to backward slashes.
+
+
+.. function:: normpath(path)
+
+   Normalize a pathname.  This collapses redundant separators and up-level
+   references so that ``A//B``, ``A/./B`` and ``A/foo/../B`` all become ``A/B``.
+   It does not normalize the case (use :func:`normcase` for that).  On Windows, it
+   converts forward slashes to backward slashes. It should be understood that this
+   may change the meaning of the path if it contains symbolic links!
+
+
+.. function:: realpath(path)
+
+   Return the canonical path of the specified filename, eliminating any symbolic
+   links encountered in the path (if they are supported by the operating system).
+
+   .. versionadded:: 2.2
+
+
+.. function:: relpath(path[, start])
+
+   Return a relative filepath to *path* either from the current directory or from
+   an optional *start* point.
+
+   *start* defaults to :attr:`os.curdir`. Availability:  Windows, Unix.
+
+   .. versionadded:: 2.6
+
+
+.. function:: samefile(path1, path2)
+
+   Return ``True`` if both pathname arguments refer to the same file or directory
+   (as indicated by device number and i-node number). Raise an exception if a
+   :func:`os.stat` call on either pathname fails. Availability:  Macintosh, Unix.
+
+
+.. function:: sameopenfile(fp1, fp2)
+
+   Return ``True`` if the file descriptors *fp1* and *fp2* refer to the same file.
+   Availability:  Macintosh, Unix.
+
+
+.. function:: samestat(stat1, stat2)
+
+   Return ``True`` if the stat tuples *stat1* and *stat2* refer to the same file.
+   These structures may have been returned by :func:`fstat`, :func:`lstat`, or
+   :func:`stat`.  This function implements the underlying comparison used by
+   :func:`samefile` and :func:`sameopenfile`. Availability:  Macintosh, Unix.
+
+
+.. function:: split(path)
+
+   Split the pathname *path* into a pair, ``(head, tail)`` where *tail* is the last
+   pathname component and *head* is everything leading up to that.  The *tail* part
+   will never contain a slash; if *path* ends in a slash, *tail* will be empty.  If
+   there is no slash in *path*, *head* will be empty.  If *path* is empty, both
+   *head* and *tail* are empty.  Trailing slashes are stripped from *head* unless
+   it is the root (one or more slashes only).  In nearly all cases, ``join(head,
+   tail)`` equals *path* (the only exception being when there were multiple slashes
+   separating *head* from *tail*).
+
+
+.. function:: splitdrive(path)
+
+   Split the pathname *path* into a pair ``(drive, tail)`` where *drive* is either
+   a drive specification or the empty string.  On systems which do not use drive
+   specifications, *drive* will always be the empty string.  In all cases, ``drive
+   + tail`` will be the same as *path*.
+
+   .. versionadded:: 1.3
+
+
+.. function:: splitext(path)
+
+   Split the pathname *path* into a pair ``(root, ext)``  such that ``root + ext ==
+   path``, and *ext* is empty or begins with a period and contains at most one
+   period. Leading periods on the basename are  ignored; ``splitext('.cshrc')``
+   returns  ``('.cshrc', '')``.
+
+   .. versionchanged:: 2.6
+      Earlier versions could produce an empty root when the only period was the
+      first character.
+
+
+.. function:: splitunc(path)
+
+   Split the pathname *path* into a pair ``(unc, rest)`` so that *unc* is the UNC
+   mount point (such as ``r'\\host\mount'``), if present, and *rest* the rest of
+   the path (such as  ``r'\path\file.ext'``).  For paths containing drive letters,
+   *unc* will always be the empty string. Availability:  Windows.
+
+
+.. function:: walk(path, visit, arg)
+
+   Calls the function *visit* with arguments ``(arg, dirname, names)`` for each
+   directory in the directory tree rooted at *path* (including *path* itself, if it
+   is a directory).  The argument *dirname* specifies the visited directory, the
+   argument *names* lists the files in the directory (gotten from
+   ``os.listdir(dirname)``). The *visit* function may modify *names* to influence
+   the set of directories visited below *dirname*, e.g. to avoid visiting certain
+   parts of the tree.  (The object referred to by *names* must be modified in
+   place, using :keyword:`del` or slice assignment.)
+
+   .. note::
+
+      Symbolic links to directories are not treated as subdirectories, and that
+      :func:`walk` therefore will not visit them. To visit linked directories you must
+      identify them with ``os.path.islink(file)`` and ``os.path.isdir(file)``, and
+      invoke :func:`walk` as necessary.
+
+   .. note::
+
+      The newer :func:`os.walk` generator supplies similar functionality and can be
+      easier to use.
+
+
+.. data:: supports_unicode_filenames
+
+   True if arbitrary Unicode strings can be used as file names (within limitations
+   imposed by the file system), and if :func:`os.listdir` returns Unicode strings
+   for a Unicode argument.
+
+   .. versionadded:: 2.3
+
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
new file mode 100644
index 0000000..5d057f1
--- /dev/null
+++ b/Doc/library/os.rst
@@ -0,0 +1,2036 @@
+
+:mod:`os` --- Miscellaneous operating system interfaces
+=======================================================
+
+.. module:: os
+   :synopsis: Miscellaneous operating system interfaces.
+
+
+This module provides a more portable way of using operating system dependent
+functionality than importing a operating system dependent built-in module like
+:mod:`posix` or :mod:`nt`. (If you just want to read or write a file see
+:func:`open`, and if you want to manipulate paths, see the :mod:`os.path`
+module.)
+
+This module searches for an operating system dependent built-in module like
+:mod:`mac` or :mod:`posix` and exports the same functions and data as found
+there.  The design of all Python's built-in operating system dependent modules
+is such that as long as the same functionality is available, it uses the same
+interface; for example, the function ``os.stat(path)`` returns stat information
+about *path* in the same format (which happens to have originated with the POSIX
+interface).
+
+Extensions peculiar to a particular operating system are also available through
+the :mod:`os` module, but using them is of course a threat to portability!
+
+Note that after the first time :mod:`os` is imported, there is *no* performance
+penalty in using functions from :mod:`os` instead of directly from the operating
+system dependent built-in module, so there should be *no* reason not to use
+:mod:`os`!
+
+The :mod:`os` module contains many functions and data values. The items below
+and in the following sub-sections are all available directly from the :mod:`os`
+module.
+
+.. % Frank Stajano  complained that it
+.. % wasn't clear that the entries described in the subsections were all
+.. % available at the module level (most uses of subsections are
+.. % different); I think this is only a problem for the HTML version,
+.. % where the relationship may not be as clear.
+.. % 
+
+
+.. exception:: error
+
+   .. index:: module: errno
+
+   This exception is raised when a function returns a system-related error (not for
+   illegal argument types or other incidental errors). This is also known as the
+   built-in exception :exc:`OSError`.  The accompanying value is a pair containing
+   the numeric error code from :cdata:`errno` and the corresponding string, as
+   would be printed by the C function :cfunc:`perror`.  See the module
+   :mod:`errno`, which contains names for the error codes defined by the underlying
+   operating system.
+
+   When exceptions are classes, this exception carries two attributes,
+   :attr:`errno` and :attr:`strerror`.  The first holds the value of the C
+   :cdata:`errno` variable, and the latter holds the corresponding error message
+   from :cfunc:`strerror`.  For exceptions that involve a file system path (such as
+   :func:`chdir` or :func:`unlink`), the exception instance will contain a third
+   attribute, :attr:`filename`, which is the file name passed to the function.
+
+
+.. data:: name
+
+   The name of the operating system dependent module imported.  The following names
+   have currently been registered: ``'posix'``, ``'nt'``, ``'mac'``, ``'os2'``,
+   ``'ce'``, ``'java'``, ``'riscos'``.
+
+
+.. data:: path
+
+   The corresponding operating system dependent standard module for pathname
+   operations, such as :mod:`posixpath` or :mod:`macpath`.  Thus, given the proper
+   imports, ``os.path.split(file)`` is equivalent to but more portable than
+   ``posixpath.split(file)``.  Note that this is also an importable module: it may
+   be imported directly as :mod:`os.path`.
+
+
+.. _os-procinfo:
+
+Process Parameters
+------------------
+
+These functions and data items provide information and operate on the current
+process and user.
+
+
+.. data:: environ
+
+   A mapping object representing the string environment. For example,
+   ``environ['HOME']`` is the pathname of your home directory (on some platforms),
+   and is equivalent to ``getenv("HOME")`` in C.
+
+   This mapping is captured the first time the :mod:`os` module is imported,
+   typically during Python startup as part of processing :file:`site.py`.  Changes
+   to the environment made after this time are not reflected in ``os.environ``,
+   except for changes made by modifying ``os.environ`` directly.
+
+   If the platform supports the :func:`putenv` function, this mapping may be used
+   to modify the environment as well as query the environment.  :func:`putenv` will
+   be called automatically when the mapping is modified.
+
+   .. note::
+
+      Calling :func:`putenv` directly does not change ``os.environ``, so it's better
+      to modify ``os.environ``.
+
+   .. note::
+
+      On some platforms, including FreeBSD and Mac OS X, setting ``environ`` may cause
+      memory leaks.  Refer to the system documentation for :cfunc:`putenv`.
+
+   If :func:`putenv` is not provided, a modified copy of this mapping  may be
+   passed to the appropriate process-creation functions to cause  child processes
+   to use a modified environment.
+
+   If the platform supports the :func:`unsetenv` function, you can  delete items in
+   this mapping to unset environment variables. :func:`unsetenv` will be called
+   automatically when an item is deleted from ``os.environ``.
+
+
+.. function:: chdir(path)
+              fchdir(fd)
+              getcwd()
+   :noindex:
+
+   These functions are described in :ref:`os-file-dir`.
+
+
+.. function:: ctermid()
+
+   Return the filename corresponding to the controlling terminal of the process.
+   Availability: Unix.
+
+
+.. function:: getegid()
+
+   Return the effective group id of the current process.  This corresponds to the
+   'set id' bit on the file being executed in the current process. Availability:
+   Unix.
+
+
+.. function:: geteuid()
+
+   .. index:: single: user; effective id
+
+   Return the current process' effective user id. Availability: Unix.
+
+
+.. function:: getgid()
+
+   .. index:: single: process; group
+
+   Return the real group id of the current process. Availability: Unix.
+
+
+.. function:: getgroups()
+
+   Return list of supplemental group ids associated with the current process.
+   Availability: Unix.
+
+
+.. function:: getlogin()
+
+   Return the name of the user logged in on the controlling terminal of the
+   process.  For most purposes, it is more useful to use the environment variable
+   :envvar:`LOGNAME` to find out who the user is, or
+   ``pwd.getpwuid(os.getuid())[0]`` to get the login name of the currently
+   effective user ID. Availability: Unix.
+
+
+.. function:: getpgid(pid)
+
+   Return the process group id of the process with process id *pid*. If *pid* is 0,
+   the process group id of the current process is returned. Availability: Unix.
+
+   .. versionadded:: 2.3
+
+
+.. function:: getpgrp()
+
+   .. index:: single: process; group
+
+   Return the id of the current process group. Availability: Unix.
+
+
+.. function:: getpid()
+
+   .. index:: single: process; id
+
+   Return the current process id. Availability: Unix, Windows.
+
+
+.. function:: getppid()
+
+   .. index:: single: process; id of parent
+
+   Return the parent's process id. Availability: Unix.
+
+
+.. function:: getuid()
+
+   .. index:: single: user; id
+
+   Return the current process' user id. Availability: Unix.
+
+
+.. function:: getenv(varname[, value])
+
+   Return the value of the environment variable *varname* if it exists, or *value*
+   if it doesn't.  *value* defaults to ``None``. Availability: most flavors of
+   Unix, Windows.
+
+
+.. function:: putenv(varname, value)
+
+   .. index:: single: environment variables; setting
+
+   Set the environment variable named *varname* to the string *value*.  Such
+   changes to the environment affect subprocesses started with :func:`os.system`,
+   :func:`popen` or :func:`fork` and :func:`execv`. Availability: most flavors of
+   Unix, Windows.
+
+   .. note::
+
+      On some platforms, including FreeBSD and Mac OS X, setting ``environ`` may cause
+      memory leaks. Refer to the system documentation for putenv.
+
+   When :func:`putenv` is supported, assignments to items in ``os.environ`` are
+   automatically translated into corresponding calls to :func:`putenv`; however,
+   calls to :func:`putenv` don't update ``os.environ``, so it is actually
+   preferable to assign to items of ``os.environ``.
+
+
+.. function:: setegid(egid)
+
+   Set the current process's effective group id. Availability: Unix.
+
+
+.. function:: seteuid(euid)
+
+   Set the current process's effective user id. Availability: Unix.
+
+
+.. function:: setgid(gid)
+
+   Set the current process' group id. Availability: Unix.
+
+
+.. function:: setgroups(groups)
+
+   Set the list of supplemental group ids associated with the current process to
+   *groups*. *groups* must be a sequence, and each element must be an integer
+   identifying a group. This operation is typical available only to the superuser.
+   Availability: Unix.
+
+   .. versionadded:: 2.2
+
+
+.. function:: setpgrp()
+
+   Calls the system call :cfunc:`setpgrp` or :cfunc:`setpgrp(0, 0)` depending on
+   which version is implemented (if any).  See the Unix manual for the semantics.
+   Availability: Unix.
+
+
+.. function:: setpgid(pid, pgrp)
+
+   Calls the system call :cfunc:`setpgid` to set the process group id of the
+   process with id *pid* to the process group with id *pgrp*.  See the Unix manual
+   for the semantics. Availability: Unix.
+
+
+.. function:: setreuid(ruid, euid)
+
+   Set the current process's real and effective user ids. Availability: Unix.
+
+
+.. function:: setregid(rgid, egid)
+
+   Set the current process's real and effective group ids. Availability: Unix.
+
+
+.. function:: getsid(pid)
+
+   Calls the system call :cfunc:`getsid`.  See the Unix manual for the semantics.
+   Availability: Unix.
+
+   .. versionadded:: 2.4
+
+
+.. function:: setsid()
+
+   Calls the system call :cfunc:`setsid`.  See the Unix manual for the semantics.
+   Availability: Unix.
+
+
+.. function:: setuid(uid)
+
+   .. index:: single: user; id, setting
+
+   Set the current process' user id. Availability: Unix.
+
+.. % placed in this section since it relates to errno.... a little weak
+
+
+.. function:: strerror(code)
+
+   Return the error message corresponding to the error code in *code*.
+   Availability: Unix, Windows.
+
+
+.. function:: umask(mask)
+
+   Set the current numeric umask and returns the previous umask. Availability:
+   Unix, Windows.
+
+
+.. function:: uname()
+
+   .. index::
+      single: gethostname() (in module socket)
+      single: gethostbyaddr() (in module socket)
+
+   Return a 5-tuple containing information identifying the current operating
+   system.  The tuple contains 5 strings: ``(sysname, nodename, release, version,
+   machine)``.  Some systems truncate the nodename to 8 characters or to the
+   leading component; a better way to get the hostname is
+   :func:`socket.gethostname`  or even
+   ``socket.gethostbyaddr(socket.gethostname())``. Availability: recent flavors of
+   Unix.
+
+
+.. function:: unsetenv(varname)
+
+   .. index:: single: environment variables; deleting
+
+   Unset (delete) the environment variable named *varname*. Such changes to the
+   environment affect subprocesses started with :func:`os.system`, :func:`popen` or
+   :func:`fork` and :func:`execv`. Availability: most flavors of Unix, Windows.
+
+   When :func:`unsetenv` is supported, deletion of items in ``os.environ`` is
+   automatically translated into a corresponding call to :func:`unsetenv`; however,
+   calls to :func:`unsetenv` don't update ``os.environ``, so it is actually
+   preferable to delete items of ``os.environ``.
+
+
+.. _os-newstreams:
+
+File Object Creation
+--------------------
+
+These functions create new file objects. (See also :func:`open`.)
+
+
+.. function:: fdopen(fd[, mode[, bufsize]])
+
+   .. index:: single: I/O control; buffering
+
+   Return an open file object connected to the file descriptor *fd*.  The *mode*
+   and *bufsize* arguments have the same meaning as the corresponding arguments to
+   the built-in :func:`open` function. Availability: Macintosh, Unix, Windows.
+
+   .. versionchanged:: 2.3
+      When specified, the *mode* argument must now start with one of the letters
+      ``'r'``, ``'w'``, or ``'a'``, otherwise a :exc:`ValueError` is raised.
+
+   .. versionchanged:: 2.5
+      On Unix, when the *mode* argument starts with ``'a'``, the *O_APPEND* flag is
+      set on the file descriptor (which the :cfunc:`fdopen` implementation already
+      does on most platforms).
+
+
+.. function:: popen(command[, mode[, bufsize]])
+
+   Open a pipe to or from *command*.  The return value is an open file object
+   connected to the pipe, which can be read or written depending on whether *mode*
+   is ``'r'`` (default) or ``'w'``. The *bufsize* argument has the same meaning as
+   the corresponding argument to the built-in :func:`open` function.  The exit
+   status of the command (encoded in the format specified for :func:`wait`) is
+   available as the return value of the :meth:`close` method of the file object,
+   except that when the exit status is zero (termination without errors), ``None``
+   is returned. Availability: Macintosh, Unix, Windows.
+
+   .. deprecated:: 2.6
+      This function is obsolete.  Use the :mod:`subprocess` module.
+
+   .. versionchanged:: 2.0
+      This function worked unreliably under Windows in earlier versions of Python.
+      This was due to the use of the :cfunc:`_popen` function from the libraries
+      provided with Windows.  Newer versions of Python do not use the broken
+      implementation from the Windows libraries.
+
+
+.. function:: tmpfile()
+
+   Return a new file object opened in update mode (``w+b``).  The file has no
+   directory entries associated with it and will be automatically deleted once
+   there are no file descriptors for the file. Availability: Macintosh, Unix,
+   Windows.
+
+
+.. _os-fd-ops:
+
+File Descriptor Operations
+--------------------------
+
+These functions operate on I/O streams referenced using file descriptors.
+
+File descriptors are small integers corresponding to a file that has been opened
+by the current process.  For example, standard input is usually file descriptor
+0, standard output is 1, and standard error is 2.  Further files opened by a
+process will then be assigned 3, 4, 5, and so forth.  The name "file descriptor"
+is slightly deceptive; on Unix platforms, sockets and pipes are also referenced
+by file descriptors.
+
+
+.. function:: close(fd)
+
+   Close file descriptor *fd*. Availability: Macintosh, Unix, Windows.
+
+   .. note::
+
+      This function is intended for low-level I/O and must be applied to a file
+      descriptor as returned by :func:`open` or :func:`pipe`.  To close a "file
+      object" returned by the built-in function :func:`open` or by :func:`popen` or
+      :func:`fdopen`, use its :meth:`close` method.
+
+
+.. function:: dup(fd)
+
+   Return a duplicate of file descriptor *fd*. Availability: Macintosh, Unix,
+   Windows.
+
+
+.. function:: dup2(fd, fd2)
+
+   Duplicate file descriptor *fd* to *fd2*, closing the latter first if necessary.
+   Availability: Macintosh, Unix, Windows.
+
+
+.. function:: fdatasync(fd)
+
+   Force write of file with filedescriptor *fd* to disk. Does not force update of
+   metadata. Availability: Unix.
+
+
+.. function:: fpathconf(fd, name)
+
+   Return system configuration information relevant to an open file. *name*
+   specifies the configuration value to retrieve; it may be a string which is the
+   name of a defined system value; these names are specified in a number of
+   standards (POSIX.1, Unix 95, Unix 98, and others).  Some platforms define
+   additional names as well.  The names known to the host operating system are
+   given in the ``pathconf_names`` dictionary.  For configuration variables not
+   included in that mapping, passing an integer for *name* is also accepted.
+   Availability: Macintosh, Unix.
+
+   If *name* is a string and is not known, :exc:`ValueError` is raised.  If a
+   specific value for *name* is not supported by the host system, even if it is
+   included in ``pathconf_names``, an :exc:`OSError` is raised with
+   :const:`errno.EINVAL` for the error number.
+
+
+.. function:: fstat(fd)
+
+   Return status for file descriptor *fd*, like :func:`stat`. Availability:
+   Macintosh, Unix, Windows.
+
+
+.. function:: fstatvfs(fd)
+
+   Return information about the filesystem containing the file associated with file
+   descriptor *fd*, like :func:`statvfs`. Availability: Unix.
+
+
+.. function:: fsync(fd)
+
+   Force write of file with filedescriptor *fd* to disk.  On Unix, this calls the
+   native :cfunc:`fsync` function; on Windows, the MS :cfunc:`_commit` function.
+
+   If you're starting with a Python file object *f*, first do ``f.flush()``, and
+   then do ``os.fsync(f.fileno())``, to ensure that all internal buffers associated
+   with *f* are written to disk. Availability: Macintosh, Unix, and Windows
+   starting in 2.2.3.
+
+
+.. function:: ftruncate(fd, length)
+
+   Truncate the file corresponding to file descriptor *fd*, so that it is at most
+   *length* bytes in size. Availability: Macintosh, Unix.
+
+
+.. function:: isatty(fd)
+
+   Return ``True`` if the file descriptor *fd* is open and connected to a
+   tty(-like) device, else ``False``. Availability: Macintosh, Unix.
+
+
+.. function:: lseek(fd, pos, how)
+
+   Set the current position of file descriptor *fd* to position *pos*, modified by
+   *how*: ``0`` to set the position relative to the beginning of the file; ``1`` to
+   set it relative to the current position; ``2`` to set it relative to the end of
+   the file. Availability: Macintosh, Unix, Windows.
+
+
+.. function:: open(file, flags[, mode])
+
+   Open the file *file* and set various flags according to *flags* and possibly its
+   mode according to *mode*. The default *mode* is ``0777`` (octal), and the
+   current umask value is first masked out.  Return the file descriptor for the
+   newly opened file. Availability: Macintosh, Unix, Windows.
+
+   For a description of the flag and mode values, see the C run-time documentation;
+   flag constants (like :const:`O_RDONLY` and :const:`O_WRONLY`) are defined in
+   this module too (see below).
+
+   .. note::
+
+      This function is intended for low-level I/O.  For normal usage, use the built-in
+      function :func:`open`, which returns a "file object" with :meth:`read` and
+      :meth:`write` methods (and many more).  To wrap a file descriptor in a "file
+      object", use :func:`fdopen`.
+
+
+.. function:: openpty()
+
+   .. index:: module: pty
+
+   Open a new pseudo-terminal pair. Return a pair of file descriptors ``(master,
+   slave)`` for the pty and the tty, respectively. For a (slightly) more portable
+   approach, use the :mod:`pty` module. Availability: Macintosh, Some flavors of
+   Unix.
+
+
+.. function:: pipe()
+
+   Create a pipe.  Return a pair of file descriptors ``(r, w)`` usable for reading
+   and writing, respectively. Availability: Macintosh, Unix, Windows.
+
+
+.. function:: read(fd, n)
+
+   Read at most *n* bytes from file descriptor *fd*. Return a string containing the
+   bytes read.  If the end of the file referred to by *fd* has been reached, an
+   empty string is returned. Availability: Macintosh, Unix, Windows.
+
+   .. note::
+
+      This function is intended for low-level I/O and must be applied to a file
+      descriptor as returned by :func:`open` or :func:`pipe`.  To read a "file object"
+      returned by the built-in function :func:`open` or by :func:`popen` or
+      :func:`fdopen`, or ``sys.stdin``, use its :meth:`read` or :meth:`readline`
+      methods.
+
+
+.. function:: tcgetpgrp(fd)
+
+   Return the process group associated with the terminal given by *fd* (an open
+   file descriptor as returned by :func:`open`). Availability: Macintosh, Unix.
+
+
+.. function:: tcsetpgrp(fd, pg)
+
+   Set the process group associated with the terminal given by *fd* (an open file
+   descriptor as returned by :func:`open`) to *pg*. Availability: Macintosh, Unix.
+
+
+.. function:: ttyname(fd)
+
+   Return a string which specifies the terminal device associated with
+   file-descriptor *fd*.  If *fd* is not associated with a terminal device, an
+   exception is raised. Availability:Macintosh, Unix.
+
+
+.. function:: write(fd, str)
+
+   Write the string *str* to file descriptor *fd*. Return the number of bytes
+   actually written. Availability: Macintosh, Unix, Windows.
+
+   .. note::
+
+      This function is intended for low-level I/O and must be applied to a file
+      descriptor as returned by :func:`open` or :func:`pipe`.  To write a "file
+      object" returned by the built-in function :func:`open` or by :func:`popen` or
+      :func:`fdopen`, or ``sys.stdout`` or ``sys.stderr``, use its :meth:`write`
+      method.
+
+The following data items are available for use in constructing the *flags*
+parameter to the :func:`open` function.  Some items will not be available on all
+platforms.  For descriptions of their availability and use, consult
+:manpage:`open(2)`.
+
+
+.. data:: O_RDONLY
+          O_WRONLY
+          O_RDWR
+          O_APPEND
+          O_CREAT
+          O_EXCL
+          O_TRUNC
+
+   Options for the *flag* argument to the :func:`open` function. These can be
+   bit-wise OR'd together. Availability: Macintosh, Unix, Windows.
+
+
+.. data:: O_DSYNC
+          O_RSYNC
+          O_SYNC
+          O_NDELAY
+          O_NONBLOCK
+          O_NOCTTY
+          O_SHLOCK
+          O_EXLOCK
+
+   More options for the *flag* argument to the :func:`open` function. Availability:
+   Macintosh, Unix.
+
+
+.. data:: O_BINARY
+
+   Option for the *flag* argument to the :func:`open` function. This can be
+   bit-wise OR'd together with those listed above. Availability: Windows.
+
+   .. % XXX need to check on the availability of this one.
+
+
+.. data:: O_NOINHERIT
+          O_SHORT_LIVED
+          O_TEMPORARY
+          O_RANDOM
+          O_SEQUENTIAL
+          O_TEXT
+
+   Options for the *flag* argument to the :func:`open` function. These can be
+   bit-wise OR'd together. Availability: Windows.
+
+
+.. data:: SEEK_SET
+          SEEK_CUR
+          SEEK_END
+
+   Parameters to the :func:`lseek` function. Their values are 0, 1, and 2,
+   respectively. Availability: Windows, Macintosh, Unix.
+
+   .. versionadded:: 2.5
+
+
+.. _os-file-dir:
+
+Files and Directories
+---------------------
+
+
+.. function:: access(path, mode)
+
+   Use the real uid/gid to test for access to *path*.  Note that most operations
+   will use the effective uid/gid, therefore this routine can be used in a
+   suid/sgid environment to test if the invoking user has the specified access to
+   *path*.  *mode* should be :const:`F_OK` to test the existence of *path*, or it
+   can be the inclusive OR of one or more of :const:`R_OK`, :const:`W_OK`, and
+   :const:`X_OK` to test permissions.  Return :const:`True` if access is allowed,
+   :const:`False` if not. See the Unix man page :manpage:`access(2)` for more
+   information. Availability: Macintosh, Unix, Windows.
+
+   .. note::
+
+      Using :func:`access` to check if a user is authorized to e.g. open a file before
+      actually doing so using :func:`open` creates a  security hole, because the user
+      might exploit the short time interval  between checking and opening the file to
+      manipulate it.
+
+   .. note::
+
+      I/O operations may fail even when :func:`access` indicates that they would
+      succeed, particularly for operations on network filesystems which may have
+      permissions semantics beyond the usual POSIX permission-bit model.
+
+
+.. data:: F_OK
+
+   Value to pass as the *mode* parameter of :func:`access` to test the existence of
+   *path*.
+
+
+.. data:: R_OK
+
+   Value to include in the *mode* parameter of :func:`access` to test the
+   readability of *path*.
+
+
+.. data:: W_OK
+
+   Value to include in the *mode* parameter of :func:`access` to test the
+   writability of *path*.
+
+
+.. data:: X_OK
+
+   Value to include in the *mode* parameter of :func:`access` to determine if
+   *path* can be executed.
+
+
+.. function:: chdir(path)
+
+   .. index:: single: directory; changing
+
+   Change the current working directory to *path*. Availability: Macintosh, Unix,
+   Windows.
+
+
+.. function:: fchdir(fd)
+
+   Change the current working directory to the directory represented by the file
+   descriptor *fd*.  The descriptor must refer to an opened directory, not an open
+   file. Availability: Unix.
+
+   .. versionadded:: 2.3
+
+
+.. function:: getcwd()
+
+   Return a string representing the current working directory. Availability:
+   Macintosh, Unix, Windows.
+
+
+.. function:: getcwdu()
+
+   Return a Unicode object representing the current working directory.
+   Availability: Macintosh, Unix, Windows.
+
+   .. versionadded:: 2.3
+
+
+.. function:: chflags(path, flags)
+
+   Set the flags of *path* to the numeric *flags*. *flags* may take a combination
+   (bitwise OR) of the following values (as defined in the :mod:`stat` module):
+
+   * ``UF_NODUMP``
+   * ``UF_IMMUTABLE``
+   * ``UF_APPEND``
+   * ``UF_OPAQUE``
+   * ``UF_NOUNLINK``
+   * ``SF_ARCHIVED``
+   * ``SF_IMMUTABLE``
+   * ``SF_APPEND``
+   * ``SF_NOUNLINK``
+   * ``SF_SNAPSHOT``
+
+   Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.6
+
+
+.. function:: chroot(path)
+
+   Change the root directory of the current process to *path*. Availability:
+   Macintosh, Unix.
+
+   .. versionadded:: 2.2
+
+
+.. function:: chmod(path, mode)
+
+   Change the mode of *path* to the numeric *mode*. *mode* may take one of the
+   following values (as defined in the :mod:`stat` module) or bitwise or-ed
+   combinations of them:
+
+   * ``stat.S_ISUID``
+   * ``stat.S_ISGID``
+   * ``stat.S_ENFMT``
+   * ``stat.S_ISVTX``
+   * ``stat.S_IREAD``
+   * ``stat.S_IWRITE``
+   * ``stat.S_IEXEC``
+   * ``stat.S_IRWXU``
+   * ``stat.S_IRUSR``
+   * ``stat.S_IWUSR``
+   * ``stat.S_IXUSR``
+   * ``stat.S_IRWXG``
+   * ``stat.S_IRGRP``
+   * ``stat.S_IWGRP``
+   * ``stat.S_IXGRP``
+   * ``stat.S_IRWXO``
+   * ``stat.S_IROTH``
+   * ``stat.S_IWOTH``
+   * ``stat.S_IXOTH``
+
+   Availability: Macintosh, Unix, Windows.
+
+   .. note::
+
+      Although Windows supports :func:`chmod`, you can only  set the file's read-only
+      flag with it (via the ``stat.S_IWRITE``  and ``stat.S_IREAD``
+      constants or a corresponding integer value).  All other bits are
+      ignored.
+
+
+.. function:: chown(path, uid, gid)
+
+   Change the owner and group id of *path* to the numeric *uid* and *gid*. To leave
+   one of the ids unchanged, set it to -1. Availability: Macintosh, Unix.
+
+
+.. function:: lchflags(path, flags)
+
+   Set the flags of *path* to the numeric *flags*, like :func:`chflags`, but do not
+   follow symbolic links. Availability: Unix.
+
+   .. versionadded:: 2.6
+
+
+.. function:: lchown(path, uid, gid)
+
+   Change the owner and group id of *path* to the numeric *uid* and gid. This
+   function will not follow symbolic links. Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. function:: link(src, dst)
+
+   Create a hard link pointing to *src* named *dst*. Availability: Macintosh, Unix.
+
+
+.. function:: listdir(path)
+
+   Return a list containing the names of the entries in the directory. The list is
+   in arbitrary order.  It does not include the special entries ``'.'`` and
+   ``'..'`` even if they are present in the directory. Availability: Macintosh,
+   Unix, Windows.
+
+   .. versionchanged:: 2.3
+      On Windows NT/2k/XP and Unix, if *path* is a Unicode object, the result will be
+      a list of Unicode objects.
+
+
+.. function:: lstat(path)
+
+   Like :func:`stat`, but do not follow symbolic links. Availability: Macintosh,
+   Unix.
+
+
+.. function:: mkfifo(path[, mode])
+
+   Create a FIFO (a named pipe) named *path* with numeric mode *mode*.  The default
+   *mode* is ``0666`` (octal).  The current umask value is first masked out from
+   the mode. Availability: Macintosh, Unix.
+
+   FIFOs are pipes that can be accessed like regular files.  FIFOs exist until they
+   are deleted (for example with :func:`os.unlink`). Generally, FIFOs are used as
+   rendezvous between "client" and "server" type processes: the server opens the
+   FIFO for reading, and the client opens it for writing.  Note that :func:`mkfifo`
+   doesn't open the FIFO --- it just creates the rendezvous point.
+
+
+.. function:: mknod(filename[, mode=0600, device])
+
+   Create a filesystem node (file, device special file or named pipe) named
+   *filename*. *mode* specifies both the permissions to use and the type of node to
+   be created, being combined (bitwise OR) with one of ``stat.S_IFREG``,
+   ``stat.S_IFCHR``, ``stat.S_IFBLK``,
+   and ``stat.S_IFIFO`` (those constants are available in :mod:`stat`).
+   For ``stat.S_IFCHR`` and
+   ``stat.S_IFBLK``, *device* defines the newly created device special file (probably using
+   :func:`os.makedev`), otherwise it is ignored.
+
+   .. versionadded:: 2.3
+
+
+.. function:: major(device)
+
+   Extracts the device major number from a raw device number (usually the
+   :attr:`st_dev` or :attr:`st_rdev` field from :ctype:`stat`).
+
+   .. versionadded:: 2.3
+
+
+.. function:: minor(device)
+
+   Extracts the device minor number from a raw device number (usually the
+   :attr:`st_dev` or :attr:`st_rdev` field from :ctype:`stat`).
+
+   .. versionadded:: 2.3
+
+
+.. function:: makedev(major, minor)
+
+   Composes a raw device number from the major and minor device numbers.
+
+   .. versionadded:: 2.3
+
+
+.. function:: mkdir(path[, mode])
+
+   Create a directory named *path* with numeric mode *mode*. The default *mode* is
+   ``0777`` (octal).  On some systems, *mode* is ignored.  Where it is used, the
+   current umask value is first masked out. Availability: Macintosh, Unix, Windows.
+
+
+.. function:: makedirs(path[, mode])
+
+   .. index::
+      single: directory; creating
+      single: UNC paths; and os.makedirs()
+
+   Recursive directory creation function.  Like :func:`mkdir`, but makes all
+   intermediate-level directories needed to contain the leaf directory.  Throws an
+   :exc:`error` exception if the leaf directory already exists or cannot be
+   created.  The default *mode* is ``0777`` (octal).  On some systems, *mode* is
+   ignored. Where it is used, the current umask value is first masked out.
+
+   .. note::
+
+      :func:`makedirs` will become confused if the path elements to create include
+      *os.pardir*.
+
+   .. versionadded:: 1.5.2
+
+   .. versionchanged:: 2.3
+      This function now handles UNC paths correctly.
+
+
+.. function:: pathconf(path, name)
+
+   Return system configuration information relevant to a named file. *name*
+   specifies the configuration value to retrieve; it may be a string which is the
+   name of a defined system value; these names are specified in a number of
+   standards (POSIX.1, Unix 95, Unix 98, and others).  Some platforms define
+   additional names as well.  The names known to the host operating system are
+   given in the ``pathconf_names`` dictionary.  For configuration variables not
+   included in that mapping, passing an integer for *name* is also accepted.
+   Availability: Macintosh, Unix.
+
+   If *name* is a string and is not known, :exc:`ValueError` is raised.  If a
+   specific value for *name* is not supported by the host system, even if it is
+   included in ``pathconf_names``, an :exc:`OSError` is raised with
+   :const:`errno.EINVAL` for the error number.
+
+
+.. data:: pathconf_names
+
+   Dictionary mapping names accepted by :func:`pathconf` and :func:`fpathconf` to
+   the integer values defined for those names by the host operating system.  This
+   can be used to determine the set of names known to the system. Availability:
+   Macintosh, Unix.
+
+
+.. function:: readlink(path)
+
+   Return a string representing the path to which the symbolic link points.  The
+   result may be either an absolute or relative pathname; if it is relative, it may
+   be converted to an absolute pathname using ``os.path.join(os.path.dirname(path),
+   result)``.
+
+   .. versionchanged:: 2.6
+      If the *path* is a Unicode object the result will also be a Unicode object.
+
+   Availability: Macintosh, Unix.
+
+
+.. function:: remove(path)
+
+   Remove the file *path*.  If *path* is a directory, :exc:`OSError` is raised; see
+   :func:`rmdir` below to remove a directory.  This is identical to the
+   :func:`unlink` function documented below.  On Windows, attempting to remove a
+   file that is in use causes an exception to be raised; on Unix, the directory
+   entry is removed but the storage allocated to the file is not made available
+   until the original file is no longer in use. Availability: Macintosh, Unix,
+   Windows.
+
+
+.. function:: removedirs(path)
+
+   .. index:: single: directory; deleting
+
+   Removes directories recursively.  Works like :func:`rmdir` except that, if the
+   leaf directory is successfully removed, :func:`removedirs`  tries to
+   successively remove every parent directory mentioned in  *path* until an error
+   is raised (which is ignored, because it generally means that a parent directory
+   is not empty). For example, ``os.removedirs('foo/bar/baz')`` will first remove
+   the directory ``'foo/bar/baz'``, and then remove ``'foo/bar'`` and ``'foo'`` if
+   they are empty. Raises :exc:`OSError` if the leaf directory could not be
+   successfully removed.
+
+   .. versionadded:: 1.5.2
+
+
+.. function:: rename(src, dst)
+
+   Rename the file or directory *src* to *dst*.  If *dst* is a directory,
+   :exc:`OSError` will be raised.  On Unix, if *dst* exists and is a file, it will
+   be removed silently if the user has permission.  The operation may fail on some
+   Unix flavors if *src* and *dst* are on different filesystems.  If successful,
+   the renaming will be an atomic operation (this is a POSIX requirement).  On
+   Windows, if *dst* already exists, :exc:`OSError` will be raised even if it is a
+   file; there may be no way to implement an atomic rename when *dst* names an
+   existing file. Availability: Macintosh, Unix, Windows.
+
+
+.. function:: renames(old, new)
+
+   Recursive directory or file renaming function. Works like :func:`rename`, except
+   creation of any intermediate directories needed to make the new pathname good is
+   attempted first. After the rename, directories corresponding to rightmost path
+   segments of the old name will be pruned away using :func:`removedirs`.
+
+   .. versionadded:: 1.5.2
+
+   .. note::
+
+      This function can fail with the new directory structure made if you lack
+      permissions needed to remove the leaf directory or file.
+
+
+.. function:: rmdir(path)
+
+   Remove the directory *path*. Availability: Macintosh, Unix, Windows.
+
+
+.. function:: stat(path)
+
+   Perform a :cfunc:`stat` system call on the given path.  The return value is an
+   object whose attributes correspond to the members of the :ctype:`stat`
+   structure, namely: :attr:`st_mode` (protection bits), :attr:`st_ino` (inode
+   number), :attr:`st_dev` (device), :attr:`st_nlink` (number of hard links),
+   :attr:`st_uid` (user ID of owner), :attr:`st_gid` (group ID of owner),
+   :attr:`st_size` (size of file, in bytes), :attr:`st_atime` (time of most recent
+   access), :attr:`st_mtime` (time of most recent content modification),
+   :attr:`st_ctime` (platform dependent; time of most recent metadata change on
+   Unix, or the time of creation on Windows)::
+
+      >>> import os
+      >>> statinfo = os.stat('somefile.txt')
+      >>> statinfo
+      (33188, 422511L, 769L, 1, 1032, 100, 926L, 1105022698,1105022732, 1105022732)
+      >>> statinfo.st_size
+      926L
+      >>>
+
+   .. versionchanged:: 2.3
+      If :func:`stat_float_times` returns true, the time values are floats, measuring
+      seconds. Fractions of a second may be reported if the system supports that. On
+      Mac OS, the times are always floats. See :func:`stat_float_times` for further
+      discussion.
+
+   On some Unix systems (such as Linux), the following attributes may also be
+   available: :attr:`st_blocks` (number of blocks allocated for file),
+   :attr:`st_blksize` (filesystem blocksize), :attr:`st_rdev` (type of device if an
+   inode device). :attr:`st_flags` (user defined flags for file).
+
+   On other Unix systems (such as FreeBSD), the following attributes may be
+   available (but may be only filled out if root tries to use them): :attr:`st_gen`
+   (file generation number), :attr:`st_birthtime` (time of file creation).
+
+   On Mac OS systems, the following attributes may also be available:
+   :attr:`st_rsize`, :attr:`st_creator`, :attr:`st_type`.
+
+   On RISCOS systems, the following attributes are also available: :attr:`st_ftype`
+   (file type), :attr:`st_attrs` (attributes), :attr:`st_obtype` (object type).
+
+   .. index:: module: stat
+
+   For backward compatibility, the return value of :func:`stat` is also accessible
+   as a tuple of at least 10 integers giving the most important (and portable)
+   members of the :ctype:`stat` structure, in the order :attr:`st_mode`,
+   :attr:`st_ino`, :attr:`st_dev`, :attr:`st_nlink`, :attr:`st_uid`,
+   :attr:`st_gid`, :attr:`st_size`, :attr:`st_atime`, :attr:`st_mtime`,
+   :attr:`st_ctime`. More items may be added at the end by some implementations.
+   The standard module :mod:`stat` defines functions and constants that are useful
+   for extracting information from a :ctype:`stat` structure. (On Windows, some
+   items are filled with dummy values.)
+
+   .. note::
+
+      The exact meaning and resolution of the :attr:`st_atime`, :attr:`st_mtime`, and
+      :attr:`st_ctime` members depends on the operating system and the file system.
+      For example, on Windows systems using the FAT or FAT32 file systems,
+      :attr:`st_mtime` has 2-second resolution, and :attr:`st_atime` has only 1-day
+      resolution.  See your operating system documentation for details.
+
+   Availability: Macintosh, Unix, Windows.
+
+   .. versionchanged:: 2.2
+      Added access to values as attributes of the returned object.
+
+   .. versionchanged:: 2.5
+      Added st_gen, st_birthtime.
+
+
+.. function:: stat_float_times([newvalue])
+
+   Determine whether :class:`stat_result` represents time stamps as float objects.
+   If *newvalue* is ``True``, future calls to :func:`stat` return floats, if it is
+   ``False``, future calls return ints. If *newvalue* is omitted, return the
+   current setting.
+
+   For compatibility with older Python versions, accessing :class:`stat_result` as
+   a tuple always returns integers.
+
+   .. versionchanged:: 2.5
+      Python now returns float values by default. Applications which do not work
+      correctly with floating point time stamps can use this function to restore the
+      old behaviour.
+
+   The resolution of the timestamps (that is the smallest possible fraction)
+   depends on the system. Some systems only support second resolution; on these
+   systems, the fraction will always be zero.
+
+   It is recommended that this setting is only changed at program startup time in
+   the *__main__* module; libraries should never change this setting. If an
+   application uses a library that works incorrectly if floating point time stamps
+   are processed, this application should turn the feature off until the library
+   has been corrected.
+
+
+.. function:: statvfs(path)
+
+   Perform a :cfunc:`statvfs` system call on the given path.  The return value is
+   an object whose attributes describe the filesystem on the given path, and
+   correspond to the members of the :ctype:`statvfs` structure, namely:
+   :attr:`f_bsize`, :attr:`f_frsize`, :attr:`f_blocks`, :attr:`f_bfree`,
+   :attr:`f_bavail`, :attr:`f_files`, :attr:`f_ffree`, :attr:`f_favail`,
+   :attr:`f_flag`, :attr:`f_namemax`. Availability: Unix.
+
+   .. index:: module: statvfs
+
+   For backward compatibility, the return value is also accessible as a tuple whose
+   values correspond to the attributes, in the order given above. The standard
+   module :mod:`statvfs` defines constants that are useful for extracting
+   information from a :ctype:`statvfs` structure when accessing it as a sequence;
+   this remains useful when writing code that needs to work with versions of Python
+   that don't support accessing the fields as attributes.
+
+   .. versionchanged:: 2.2
+      Added access to values as attributes of the returned object.
+
+
+.. function:: symlink(src, dst)
+
+   Create a symbolic link pointing to *src* named *dst*. Availability: Unix.
+
+
+.. function:: tempnam([dir[, prefix]])
+
+   Return a unique path name that is reasonable for creating a temporary file.
+   This will be an absolute path that names a potential directory entry in the
+   directory *dir* or a common location for temporary files if *dir* is omitted or
+   ``None``.  If given and not ``None``, *prefix* is used to provide a short prefix
+   to the filename.  Applications are responsible for properly creating and
+   managing files created using paths returned by :func:`tempnam`; no automatic
+   cleanup is provided. On Unix, the environment variable :envvar:`TMPDIR`
+   overrides *dir*, while on Windows the :envvar:`TMP` is used.  The specific
+   behavior of this function depends on the C library implementation; some aspects
+   are underspecified in system documentation.
+
+   .. warning::
+
+      Use of :func:`tempnam` is vulnerable to symlink attacks; consider using
+      :func:`tmpfile` (section :ref:`os-newstreams`) instead.
+
+   Availability: Macintosh, Unix, Windows.
+
+
+.. function:: tmpnam()
+
+   Return a unique path name that is reasonable for creating a temporary file.
+   This will be an absolute path that names a potential directory entry in a common
+   location for temporary files.  Applications are responsible for properly
+   creating and managing files created using paths returned by :func:`tmpnam`; no
+   automatic cleanup is provided.
+
+   .. warning::
+
+      Use of :func:`tmpnam` is vulnerable to symlink attacks; consider using
+      :func:`tmpfile` (section :ref:`os-newstreams`) instead.
+
+   Availability: Unix, Windows.  This function probably shouldn't be used on
+   Windows, though: Microsoft's implementation of :func:`tmpnam` always creates a
+   name in the root directory of the current drive, and that's generally a poor
+   location for a temp file (depending on privileges, you may not even be able to
+   open a file using this name).
+
+
+.. data:: TMP_MAX
+
+   The maximum number of unique names that :func:`tmpnam` will generate before
+   reusing names.
+
+
+.. function:: unlink(path)
+
+   Remove the file *path*.  This is the same function as :func:`remove`; the
+   :func:`unlink` name is its traditional Unix name. Availability: Macintosh, Unix,
+   Windows.
+
+
+.. function:: utime(path, times)
+
+   Set the access and modified times of the file specified by *path*. If *times* is
+   ``None``, then the file's access and modified times are set to the current time.
+   Otherwise, *times* must be a 2-tuple of numbers, of the form ``(atime, mtime)``
+   which is used to set the access and modified times, respectively. Whether a
+   directory can be given for *path* depends on whether the operating system
+   implements directories as files (for example, Windows does not).  Note that the
+   exact times you set here may not be returned by a subsequent :func:`stat` call,
+   depending on the resolution with which your operating system records access and
+   modification times; see :func:`stat`.
+
+   .. versionchanged:: 2.0
+      Added support for ``None`` for *times*.
+
+   Availability: Macintosh, Unix, Windows.
+
+
+.. function:: walk(top[, topdown=True [, onerror=None[, followlinks=False]]])
+
+   .. index::
+      single: directory; walking
+      single: directory; traversal
+
+   :func:`walk` generates the file names in a directory tree, by walking the tree
+   either top down or bottom up. For each directory in the tree rooted at directory
+   *top* (including *top* itself), it yields a 3-tuple ``(dirpath, dirnames,
+   filenames)``.
+
+   *dirpath* is a string, the path to the directory.  *dirnames* is a list of the
+   names of the subdirectories in *dirpath* (excluding ``'.'`` and ``'..'``).
+   *filenames* is a list of the names of the non-directory files in *dirpath*.
+   Note that the names in the lists contain no path components.  To get a full path
+   (which begins with *top*) to a file or directory in *dirpath*, do
+   ``os.path.join(dirpath, name)``.
+
+   If optional argument *topdown* is true or not specified, the triple for a
+   directory is generated before the triples for any of its subdirectories
+   (directories are generated top down).  If *topdown* is false, the triple for a
+   directory is generated after the triples for all of its subdirectories
+   (directories are generated bottom up).
+
+   When *topdown* is true, the caller can modify the *dirnames* list in-place
+   (perhaps using :keyword:`del` or slice assignment), and :func:`walk` will only
+   recurse into the subdirectories whose names remain in *dirnames*; this can be
+   used to prune the search, impose a specific order of visiting, or even to inform
+   :func:`walk` about directories the caller creates or renames before it resumes
+   :func:`walk` again.  Modifying *dirnames* when *topdown* is false is
+   ineffective, because in bottom-up mode the directories in *dirnames* are
+   generated before *dirpath* itself is generated.
+
+   By default errors from the ``os.listdir()`` call are ignored.  If optional
+   argument *onerror* is specified, it should be a function; it will be called with
+   one argument, an :exc:`OSError` instance.  It can report the error to continue
+   with the walk, or raise the exception to abort the walk.  Note that the filename
+   is available as the ``filename`` attribute of the exception object.
+
+   By default, :func:`walk` will not walk down into symbolic links that resolve to
+   directories. Set *followlinks* to True to visit directories pointed to by
+   symlinks, on systems that support them.
+
+   .. versionadded:: 2.6
+      The *followlinks* parameter.
+
+   .. note::
+
+      Be aware that setting *followlinks* to true can lead to infinite recursion if a
+      link points to a parent directory of itself. :func:`walk` does not keep track of
+      the directories it visited already.
+
+   .. note::
+
+      If you pass a relative pathname, don't change the current working directory
+      between resumptions of :func:`walk`.  :func:`walk` never changes the current
+      directory, and assumes that its caller doesn't either.
+
+   This example displays the number of bytes taken by non-directory files in each
+   directory under the starting directory, except that it doesn't look under any
+   CVS subdirectory::
+
+      import os
+      from os.path import join, getsize
+      for root, dirs, files in os.walk('python/Lib/email'):
+          print root, "consumes",
+          print sum(getsize(join(root, name)) for name in files),
+          print "bytes in", len(files), "non-directory files"
+          if 'CVS' in dirs:
+              dirs.remove('CVS')  # don't visit CVS directories
+
+   In the next example, walking the tree bottom up is essential: :func:`rmdir`
+   doesn't allow deleting a directory before the directory is empty::
+
+      # Delete everything reachable from the directory named in 'top',
+      # assuming there are no symbolic links.
+      # CAUTION:  This is dangerous!  For example, if top == '/', it
+      # could delete all your disk files.
+      import os
+      for root, dirs, files in os.walk(top, topdown=False):
+          for name in files:
+              os.remove(os.path.join(root, name))
+          for name in dirs:
+              os.rmdir(os.path.join(root, name))
+
+   .. versionadded:: 2.3
+
+
+.. _os-process:
+
+Process Management
+------------------
+
+These functions may be used to create and manage processes.
+
+The various :func:`exec\*` functions take a list of arguments for the new
+program loaded into the process.  In each case, the first of these arguments is
+passed to the new program as its own name rather than as an argument a user may
+have typed on a command line.  For the C programmer, this is the ``argv[0]``
+passed to a program's :cfunc:`main`.  For example, ``os.execv('/bin/echo',
+['foo', 'bar'])`` will only print ``bar`` on standard output; ``foo`` will seem
+to be ignored.
+
+
+.. function:: abort()
+
+   Generate a :const:`SIGABRT` signal to the current process.  On Unix, the default
+   behavior is to produce a core dump; on Windows, the process immediately returns
+   an exit code of ``3``.  Be aware that programs which use :func:`signal.signal`
+   to register a handler for :const:`SIGABRT` will behave differently.
+   Availability: Macintosh, Unix, Windows.
+
+
+.. function:: execl(path, arg0, arg1, ...)
+              execle(path, arg0, arg1, ..., env)
+              execlp(file, arg0, arg1, ...)
+              execlpe(file, arg0, arg1, ..., env)
+              execv(path, args)
+              execve(path, args, env)
+              execvp(file, args)
+              execvpe(file, args, env)
+
+   These functions all execute a new program, replacing the current process; they
+   do not return.  On Unix, the new executable is loaded into the current process,
+   and will have the same process ID as the caller.  Errors will be reported as
+   :exc:`OSError` exceptions.
+
+   The ``'l'`` and ``'v'`` variants of the :func:`exec\*` functions differ in how
+   command-line arguments are passed.  The ``'l'`` variants are perhaps the easiest
+   to work with if the number of parameters is fixed when the code is written; the
+   individual parameters simply become additional parameters to the :func:`execl\*`
+   functions.  The ``'v'`` variants are good when the number of parameters is
+   variable, with the arguments being passed in a list or tuple as the *args*
+   parameter.  In either case, the arguments to the child process should start with
+   the name of the command being run, but this is not enforced.
+
+   The variants which include a ``'p'`` near the end (:func:`execlp`,
+   :func:`execlpe`, :func:`execvp`, and :func:`execvpe`) will use the
+   :envvar:`PATH` environment variable to locate the program *file*.  When the
+   environment is being replaced (using one of the :func:`exec\*e` variants,
+   discussed in the next paragraph), the new environment is used as the source of
+   the :envvar:`PATH` variable. The other variants, :func:`execl`, :func:`execle`,
+   :func:`execv`, and :func:`execve`, will not use the :envvar:`PATH` variable to
+   locate the executable; *path* must contain an appropriate absolute or relative
+   path.
+
+   For :func:`execle`, :func:`execlpe`, :func:`execve`, and :func:`execvpe` (note
+   that these all end in ``'e'``), the *env* parameter must be a mapping which is
+   used to define the environment variables for the new process; the :func:`execl`,
+   :func:`execlp`, :func:`execv`, and :func:`execvp` all cause the new process to
+   inherit the environment of the current process. Availability: Macintosh, Unix,
+   Windows.
+
+
+.. function:: _exit(n)
+
+   Exit to the system with status *n*, without calling cleanup handlers, flushing
+   stdio buffers, etc. Availability: Macintosh, Unix, Windows.
+
+   .. note::
+
+      The standard way to exit is ``sys.exit(n)``. :func:`_exit` should normally only
+      be used in the child process after a :func:`fork`.
+
+The following exit codes are a defined, and can be used with :func:`_exit`,
+although they are not required.  These are typically used for system programs
+written in Python, such as a mail server's external command delivery program.
+
+.. note::
+
+   Some of these may not be available on all Unix platforms, since there is some
+   variation.  These constants are defined where they are defined by the underlying
+   platform.
+
+
+.. data:: EX_OK
+
+   Exit code that means no error occurred. Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_USAGE
+
+   Exit code that means the command was used incorrectly, such as when the wrong
+   number of arguments are given. Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_DATAERR
+
+   Exit code that means the input data was incorrect. Availability: Macintosh,
+   Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_NOINPUT
+
+   Exit code that means an input file did not exist or was not readable.
+   Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_NOUSER
+
+   Exit code that means a specified user did not exist. Availability: Macintosh,
+   Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_NOHOST
+
+   Exit code that means a specified host did not exist. Availability: Macintosh,
+   Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_UNAVAILABLE
+
+   Exit code that means that a required service is unavailable. Availability:
+   Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_SOFTWARE
+
+   Exit code that means an internal software error was detected. Availability:
+   Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_OSERR
+
+   Exit code that means an operating system error was detected, such as the
+   inability to fork or create a pipe. Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_OSFILE
+
+   Exit code that means some system file did not exist, could not be opened, or had
+   some other kind of error. Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_CANTCREAT
+
+   Exit code that means a user specified output file could not be created.
+   Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_IOERR
+
+   Exit code that means that an error occurred while doing I/O on some file.
+   Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_TEMPFAIL
+
+   Exit code that means a temporary failure occurred.  This indicates something
+   that may not really be an error, such as a network connection that couldn't be
+   made during a retryable operation. Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_PROTOCOL
+
+   Exit code that means that a protocol exchange was illegal, invalid, or not
+   understood. Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_NOPERM
+
+   Exit code that means that there were insufficient permissions to perform the
+   operation (but not intended for file system problems). Availability: Macintosh,
+   Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_CONFIG
+
+   Exit code that means that some kind of configuration error occurred.
+   Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. data:: EX_NOTFOUND
+
+   Exit code that means something like "an entry was not found". Availability:
+   Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. function:: fork()
+
+   Fork a child process.  Return ``0`` in the child, the child's process id in the
+   parent. Availability: Macintosh, Unix.
+
+
+.. function:: forkpty()
+
+   Fork a child process, using a new pseudo-terminal as the child's controlling
+   terminal. Return a pair of ``(pid, fd)``, where *pid* is ``0`` in the child, the
+   new child's process id in the parent, and *fd* is the file descriptor of the
+   master end of the pseudo-terminal.  For a more portable approach, use the
+   :mod:`pty` module. Availability: Macintosh, Some flavors of Unix.
+
+
+.. function:: kill(pid, sig)
+
+   .. index::
+      single: process; killing
+      single: process; signalling
+
+   Send signal *sig* to the process *pid*.  Constants for the specific signals
+   available on the host platform are defined in the :mod:`signal` module.
+   Availability: Macintosh, Unix.
+
+
+.. function:: killpg(pgid, sig)
+
+   .. index::
+      single: process; killing
+      single: process; signalling
+
+   Send the signal *sig* to the process group *pgid*. Availability: Macintosh,
+   Unix.
+
+   .. versionadded:: 2.3
+
+
+.. function:: nice(increment)
+
+   Add *increment* to the process's "niceness".  Return the new niceness.
+   Availability: Macintosh, Unix.
+
+
+.. function:: plock(op)
+
+   Lock program segments into memory.  The value of *op* (defined in
+   ````) determines which segments are locked. Availability: Macintosh,
+   Unix.
+
+
+.. function:: popen(...)
+   :noindex:
+
+   Run child processes, returning opened pipes for communications.  These functions
+   are described in section :ref:`os-newstreams`.
+
+
+.. function:: spawnl(mode, path, ...)
+              spawnle(mode, path, ..., env)
+              spawnlp(mode, file, ...)
+              spawnlpe(mode, file, ..., env)
+              spawnv(mode, path, args)
+              spawnve(mode, path, args, env)
+              spawnvp(mode, file, args)
+              spawnvpe(mode, file, args, env)
+
+   Execute the program *path* in a new process.
+
+   (Note that the :mod:`subprocess` module provides more powerful facilities for
+   spawning new processes and retrieving their results; using that module is
+   preferable to using these functions.)
+
+   If *mode* is :const:`P_NOWAIT`, this function returns the process ID of the new
+   process; if *mode* is :const:`P_WAIT`, returns the process's exit code if it
+   exits normally, or ``-signal``, where *signal* is the signal that killed the
+   process.  On Windows, the process ID will actually be the process handle, so can
+   be used with the :func:`waitpid` function.
+
+   The ``'l'`` and ``'v'`` variants of the :func:`spawn\*` functions differ in how
+   command-line arguments are passed.  The ``'l'`` variants are perhaps the easiest
+   to work with if the number of parameters is fixed when the code is written; the
+   individual parameters simply become additional parameters to the
+   :func:`spawnl\*` functions.  The ``'v'`` variants are good when the number of
+   parameters is variable, with the arguments being passed in a list or tuple as
+   the *args* parameter.  In either case, the arguments to the child process must
+   start with the name of the command being run.
+
+   The variants which include a second ``'p'`` near the end (:func:`spawnlp`,
+   :func:`spawnlpe`, :func:`spawnvp`, and :func:`spawnvpe`) will use the
+   :envvar:`PATH` environment variable to locate the program *file*.  When the
+   environment is being replaced (using one of the :func:`spawn\*e` variants,
+   discussed in the next paragraph), the new environment is used as the source of
+   the :envvar:`PATH` variable.  The other variants, :func:`spawnl`,
+   :func:`spawnle`, :func:`spawnv`, and :func:`spawnve`, will not use the
+   :envvar:`PATH` variable to locate the executable; *path* must contain an
+   appropriate absolute or relative path.
+
+   For :func:`spawnle`, :func:`spawnlpe`, :func:`spawnve`, and :func:`spawnvpe`
+   (note that these all end in ``'e'``), the *env* parameter must be a mapping
+   which is used to define the environment variables for the new process; the
+   :func:`spawnl`, :func:`spawnlp`, :func:`spawnv`, and :func:`spawnvp` all cause
+   the new process to inherit the environment of the current process.
+
+   As an example, the following calls to :func:`spawnlp` and :func:`spawnvpe` are
+   equivalent::
+
+      import os
+      os.spawnlp(os.P_WAIT, 'cp', 'cp', 'index.html', '/dev/null')
+
+      L = ['cp', 'index.html', '/dev/null']
+      os.spawnvpe(os.P_WAIT, 'cp', L, os.environ)
+
+   Availability: Unix, Windows.  :func:`spawnlp`, :func:`spawnlpe`, :func:`spawnvp`
+   and :func:`spawnvpe` are not available on Windows.
+
+   .. versionadded:: 1.6
+
+
+.. data:: P_NOWAIT
+          P_NOWAITO
+
+   Possible values for the *mode* parameter to the :func:`spawn\*` family of
+   functions.  If either of these values is given, the :func:`spawn\*` functions
+   will return as soon as the new process has been created, with the process ID as
+   the return value. Availability: Macintosh, Unix, Windows.
+
+   .. versionadded:: 1.6
+
+
+.. data:: P_WAIT
+
+   Possible value for the *mode* parameter to the :func:`spawn\*` family of
+   functions.  If this is given as *mode*, the :func:`spawn\*` functions will not
+   return until the new process has run to completion and will return the exit code
+   of the process the run is successful, or ``-signal`` if a signal kills the
+   process. Availability: Macintosh, Unix, Windows.
+
+   .. versionadded:: 1.6
+
+
+.. data:: P_DETACH
+          P_OVERLAY
+
+   Possible values for the *mode* parameter to the :func:`spawn\*` family of
+   functions.  These are less portable than those listed above. :const:`P_DETACH`
+   is similar to :const:`P_NOWAIT`, but the new process is detached from the
+   console of the calling process. If :const:`P_OVERLAY` is used, the current
+   process will be replaced; the :func:`spawn\*` function will not return.
+   Availability: Windows.
+
+   .. versionadded:: 1.6
+
+
+.. function:: startfile(path[, operation])
+
+   Start a file with its associated application.
+
+   When *operation* is not specified or ``'open'``, this acts like double-clicking
+   the file in Windows Explorer, or giving the file name as an argument to the
+   :program:`start` command from the interactive command shell: the file is opened
+   with whatever application (if any) its extension is associated.
+
+   When another *operation* is given, it must be a "command verb" that specifies
+   what should be done with the file. Common verbs documented by Microsoft are
+   ``'print'`` and  ``'edit'`` (to be used on files) as well as ``'explore'`` and
+   ``'find'`` (to be used on directories).
+
+   :func:`startfile` returns as soon as the associated application is launched.
+   There is no option to wait for the application to close, and no way to retrieve
+   the application's exit status.  The *path* parameter is relative to the current
+   directory.  If you want to use an absolute path, make sure the first character
+   is not a slash (``'/'``); the underlying Win32 :cfunc:`ShellExecute` function
+   doesn't work if it is.  Use the :func:`os.path.normpath` function to ensure that
+   the path is properly encoded for Win32. Availability: Windows.
+
+   .. versionadded:: 2.0
+
+   .. versionadded:: 2.5
+      The *operation* parameter.
+
+
+.. function:: system(command)
+
+   Execute the command (a string) in a subshell.  This is implemented by calling
+   the Standard C function :cfunc:`system`, and has the same limitations.  Changes
+   to ``posix.environ``, ``sys.stdin``, etc. are not reflected in the environment
+   of the executed command.
+
+   On Unix, the return value is the exit status of the process encoded in the
+   format specified for :func:`wait`.  Note that POSIX does not specify the meaning
+   of the return value of the C :cfunc:`system` function, so the return value of
+   the Python function is system-dependent.
+
+   On Windows, the return value is that returned by the system shell after running
+   *command*, given by the Windows environment variable :envvar:`COMSPEC`: on
+   :program:`command.com` systems (Windows 95, 98 and ME) this is always ``0``; on
+   :program:`cmd.exe` systems (Windows NT, 2000 and XP) this is the exit status of
+   the command run; on systems using a non-native shell, consult your shell
+   documentation.
+
+   Availability: Macintosh, Unix, Windows.
+
+   The :mod:`subprocess` module provides more powerful facilities for spawning new
+   processes and retrieving their results; using that module is preferable to using
+   this function.
+
+
+.. function:: times()
+
+   Return a 5-tuple of floating point numbers indicating accumulated (processor or
+   other) times, in seconds.  The items are: user time, system time, children's
+   user time, children's system time, and elapsed real time since a fixed point in
+   the past, in that order.  See the Unix manual page :manpage:`times(2)` or the
+   corresponding Windows Platform API documentation. Availability: Macintosh, Unix,
+   Windows.
+
+
+.. function:: wait()
+
+   Wait for completion of a child process, and return a tuple containing its pid
+   and exit status indication: a 16-bit number, whose low byte is the signal number
+   that killed the process, and whose high byte is the exit status (if the signal
+   number is zero); the high bit of the low byte is set if a core file was
+   produced. Availability: Macintosh, Unix.
+
+
+.. function:: waitpid(pid, options)
+
+   The details of this function differ on Unix and Windows.
+
+   On Unix: Wait for completion of a child process given by process id *pid*, and
+   return a tuple containing its process id and exit status indication (encoded as
+   for :func:`wait`).  The semantics of the call are affected by the value of the
+   integer *options*, which should be ``0`` for normal operation.
+
+   If *pid* is greater than ``0``, :func:`waitpid` requests status information for
+   that specific process.  If *pid* is ``0``, the request is for the status of any
+   child in the process group of the current process.  If *pid* is ``-1``, the
+   request pertains to any child of the current process.  If *pid* is less than
+   ``-1``, status is requested for any process in the process group ``-pid`` (the
+   absolute value of *pid*).
+
+   On Windows: Wait for completion of a process given by process handle *pid*, and
+   return a tuple containing *pid*, and its exit status shifted left by 8 bits
+   (shifting makes cross-platform use of the function easier). A *pid* less than or
+   equal to ``0`` has no special meaning on Windows, and raises an exception. The
+   value of integer *options* has no effect. *pid* can refer to any process whose
+   id is known, not necessarily a child process. The :func:`spawn` functions called
+   with :const:`P_NOWAIT` return suitable process handles.
+
+
+.. function:: wait3([options])
+
+   Similar to :func:`waitpid`, except no process id argument is given and a
+   3-element tuple containing the child's process id, exit status indication, and
+   resource usage information is returned.  Refer to :mod:`resource`.\
+   :func:`getrusage` for details on resource usage information.  The option
+   argument is the same as that provided to :func:`waitpid` and :func:`wait4`.
+   Availability: Unix.
+
+   .. versionadded:: 2.5
+
+
+.. function:: wait4(pid, options)
+
+   Similar to :func:`waitpid`, except a 3-element tuple, containing the child's
+   process id, exit status indication, and resource usage information is returned.
+   Refer to :mod:`resource`.\ :func:`getrusage` for details on resource usage
+   information.  The arguments to :func:`wait4` are the same as those provided to
+   :func:`waitpid`. Availability: Unix.
+
+   .. versionadded:: 2.5
+
+
+.. data:: WNOHANG
+
+   The option for :func:`waitpid` to return immediately if no child process status
+   is available immediately. The function returns ``(0, 0)`` in this case.
+   Availability: Macintosh, Unix.
+
+
+.. data:: WCONTINUED
+
+   This option causes child processes to be reported if they have been continued
+   from a job control stop since their status was last reported. Availability: Some
+   Unix systems.
+
+   .. versionadded:: 2.3
+
+
+.. data:: WUNTRACED
+
+   This option causes child processes to be reported if they have been stopped but
+   their current state has not been reported since they were stopped. Availability:
+   Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+The following functions take a process status code as returned by
+:func:`system`, :func:`wait`, or :func:`waitpid` as a parameter.  They may be
+used to determine the disposition of a process.
+
+
+.. function:: WCOREDUMP(status)
+
+   Returns ``True`` if a core dump was generated for the process, otherwise it
+   returns ``False``. Availability: Macintosh, Unix.
+
+   .. versionadded:: 2.3
+
+
+.. function:: WIFCONTINUED(status)
+
+   Returns ``True`` if the process has been continued from a job control stop,
+   otherwise it returns ``False``. Availability: Unix.
+
+   .. versionadded:: 2.3
+
+
+.. function:: WIFSTOPPED(status)
+
+   Returns ``True`` if the process has been stopped, otherwise it returns
+   ``False``. Availability: Unix.
+
+
+.. function:: WIFSIGNALED(status)
+
+   Returns ``True`` if the process exited due to a signal, otherwise it returns
+   ``False``. Availability: Macintosh, Unix.
+
+
+.. function:: WIFEXITED(status)
+
+   Returns ``True`` if the process exited using the :manpage:`exit(2)` system call,
+   otherwise it returns ``False``. Availability: Macintosh, Unix.
+
+
+.. function:: WEXITSTATUS(status)
+
+   If ``WIFEXITED(status)`` is true, return the integer parameter to the
+   :manpage:`exit(2)` system call.  Otherwise, the return value is meaningless.
+   Availability: Macintosh, Unix.
+
+
+.. function:: WSTOPSIG(status)
+
+   Return the signal which caused the process to stop. Availability: Macintosh,
+   Unix.
+
+
+.. function:: WTERMSIG(status)
+
+   Return the signal which caused the process to exit. Availability: Macintosh,
+   Unix.
+
+
+.. _os-path:
+
+Miscellaneous System Information
+--------------------------------
+
+
+.. function:: confstr(name)
+
+   Return string-valued system configuration values. *name* specifies the
+   configuration value to retrieve; it may be a string which is the name of a
+   defined system value; these names are specified in a number of standards (POSIX,
+   Unix 95, Unix 98, and others).  Some platforms define additional names as well.
+   The names known to the host operating system are given as the keys of the
+   ``confstr_names`` dictionary.  For configuration variables not included in that
+   mapping, passing an integer for *name* is also accepted. Availability:
+   Macintosh, Unix.
+
+   If the configuration value specified by *name* isn't defined, ``None`` is
+   returned.
+
+   If *name* is a string and is not known, :exc:`ValueError` is raised.  If a
+   specific value for *name* is not supported by the host system, even if it is
+   included in ``confstr_names``, an :exc:`OSError` is raised with
+   :const:`errno.EINVAL` for the error number.
+
+
+.. data:: confstr_names
+
+   Dictionary mapping names accepted by :func:`confstr` to the integer values
+   defined for those names by the host operating system. This can be used to
+   determine the set of names known to the system. Availability: Macintosh, Unix.
+
+
+.. function:: getloadavg()
+
+   Return the number of processes in the system run queue averaged over the last 1,
+   5, and 15 minutes or raises :exc:`OSError` if the load  average was
+   unobtainable.
+
+   .. versionadded:: 2.3
+
+
+.. function:: sysconf(name)
+
+   Return integer-valued system configuration values. If the configuration value
+   specified by *name* isn't defined, ``-1`` is returned.  The comments regarding
+   the *name* parameter for :func:`confstr` apply here as well; the dictionary that
+   provides information on the known names is given by ``sysconf_names``.
+   Availability: Macintosh, Unix.
+
+
+.. data:: sysconf_names
+
+   Dictionary mapping names accepted by :func:`sysconf` to the integer values
+   defined for those names by the host operating system. This can be used to
+   determine the set of names known to the system. Availability: Macintosh, Unix.
+
+The follow data values are used to support path manipulation operations.  These
+are defined for all platforms.
+
+Higher-level operations on pathnames are defined in the :mod:`os.path` module.
+
+
+.. data:: curdir
+
+   The constant string used by the operating system to refer to the current
+   directory. For example: ``'.'`` for POSIX or ``':'`` for Mac OS 9. Also
+   available via :mod:`os.path`.
+
+
+.. data:: pardir
+
+   The constant string used by the operating system to refer to the parent
+   directory. For example: ``'..'`` for POSIX or ``'::'`` for Mac OS 9. Also
+   available via :mod:`os.path`.
+
+
+.. data:: sep
+
+   The character used by the operating system to separate pathname components, for
+   example, ``'/'`` for POSIX or ``':'`` for Mac OS 9.  Note that knowing this is
+   not sufficient to be able to parse or concatenate pathnames --- use
+   :func:`os.path.split` and :func:`os.path.join` --- but it is occasionally
+   useful. Also available via :mod:`os.path`.
+
+
+.. data:: altsep
+
+   An alternative character used by the operating system to separate pathname
+   components, or ``None`` if only one separator character exists.  This is set to
+   ``'/'`` on Windows systems where ``sep`` is a backslash. Also available via
+   :mod:`os.path`.
+
+
+.. data:: extsep
+
+   The character which separates the base filename from the extension; for example,
+   the ``'.'`` in :file:`os.py`. Also available via :mod:`os.path`.
+
+   .. versionadded:: 2.2
+
+
+.. data:: pathsep
+
+   The character conventionally used by the operating system to separate search
+   path components (as in :envvar:`PATH`), such as ``':'`` for POSIX or ``';'`` for
+   Windows. Also available via :mod:`os.path`.
+
+
+.. data:: defpath
+
+   The default search path used by :func:`exec\*p\*` and :func:`spawn\*p\*` if the
+   environment doesn't have a ``'PATH'`` key. Also available via :mod:`os.path`.
+
+
+.. data:: linesep
+
+   The string used to separate (or, rather, terminate) lines on the current
+   platform.  This may be a single character, such as  ``'\n'`` for POSIX or
+   ``'\r'`` for Mac OS, or multiple  characters, for example, ``'\r\n'`` for
+   Windows. Do not use *os.linesep* as a line terminator when writing files  opened
+   in text mode (the default); use a single ``'\n'`` instead,  on all platforms.
+
+
+.. data:: devnull
+
+   The file path of the null device. For example: ``'/dev/null'`` for POSIX or
+   ``'Dev:Nul'`` for Mac OS 9. Also available via :mod:`os.path`.
+
+   .. versionadded:: 2.4
+
+
+.. _os-miscfunc:
+
+Miscellaneous Functions
+-----------------------
+
+
+.. function:: urandom(n)
+
+   Return a string of *n* random bytes suitable for cryptographic use.
+
+   This function returns random bytes from an OS-specific randomness source.  The
+   returned data should be unpredictable enough for cryptographic applications,
+   though its exact quality depends on the OS implementation.  On a UNIX-like
+   system this will query /dev/urandom, and on Windows it will use CryptGenRandom.
+   If a randomness source is not found, :exc:`NotImplementedError` will be raised.
+
+   .. versionadded:: 2.4
+
diff --git a/Doc/library/ossaudiodev.rst b/Doc/library/ossaudiodev.rst
new file mode 100644
index 0000000..066b26b
--- /dev/null
+++ b/Doc/library/ossaudiodev.rst
@@ -0,0 +1,429 @@
+
+:mod:`ossaudiodev` --- Access to OSS-compatible audio devices
+=============================================================
+
+.. module:: ossaudiodev
+   :platform: Linux, FreeBSD
+   :synopsis: Access to OSS-compatible audio devices.
+
+
+.. versionadded:: 2.3
+
+This module allows you to access the OSS (Open Sound System) audio interface.
+OSS is available for a wide range of open-source and commercial Unices, and is
+the standard audio interface for Linux and recent versions of FreeBSD.
+
+.. % Things will get more complicated for future Linux versions, since
+.. % ALSA is in the standard kernel as of 2.5.x.  Presumably if you
+.. % use ALSA, you'll have to make sure its OSS compatibility layer
+.. % is active to use ossaudiodev, but you're gonna need it for the vast
+.. % majority of Linux audio apps anyways.
+.. % 
+.. % Sounds like things are also complicated for other BSDs.  In response
+.. % to my python-dev query, Thomas Wouters said:
+.. % 
+.. % > Likewise, googling shows OpenBSD also uses OSS/Free -- the commercial
+.. % > OSS installation manual tells you to remove references to OSS/Free from the
+.. % > kernel :)
+.. % 
+.. % but Aleksander Piotrowsk actually has an OpenBSD box, and he quotes
+.. % from its :
+.. % >  * WARNING!  WARNING!
+.. % >  * This is an OSS (Linux) audio emulator.
+.. % >  * Use the Native NetBSD API for developing new code, and this
+.. % >  * only for compiling Linux programs.
+.. % 
+.. % There's also an ossaudio manpage on OpenBSD that explains things
+.. % further.  Presumably NetBSD and OpenBSD have a different standard
+.. % audio interface.  That's the great thing about standards, there are so
+.. % many to choose from ... ;-)
+.. % 
+.. % This probably all warrants a footnote or two, but I don't understand
+.. % things well enough right now to write it!   --GPW
+
+
+.. seealso::
+
+   `Open Sound System Programmer's Guide `_
+      the official documentation for the OSS C API
+
+   The module defines a large number of constants supplied by the OSS device
+   driver; see ```` on either Linux or FreeBSD for a listing .
+
+:mod:`ossaudiodev` defines the following variables and functions:
+
+
+.. exception:: OSSAudioError
+
+   This exception is raised on certain errors.  The argument is a string describing
+   what went wrong.
+
+   (If :mod:`ossaudiodev` receives an error from a system call such as
+   :cfunc:`open`, :cfunc:`write`, or :cfunc:`ioctl`, it raises :exc:`IOError`.
+   Errors detected directly by :mod:`ossaudiodev` result in :exc:`OSSAudioError`.)
+
+   (For backwards compatibility, the exception class is also available as
+   ``ossaudiodev.error``.)
+
+
+.. function:: open([device, ]mode)
+
+   Open an audio device and return an OSS audio device object.  This object
+   supports many file-like methods, such as :meth:`read`, :meth:`write`, and
+   :meth:`fileno` (although there are subtle differences between conventional Unix
+   read/write semantics and those of OSS audio devices).  It also supports a number
+   of audio-specific methods; see below for the complete list of methods.
+
+   *device* is the audio device filename to use.  If it is not specified, this
+   module first looks in the environment variable :envvar:`AUDIODEV` for a device
+   to use.  If not found, it falls back to :file:`/dev/dsp`.
+
+   *mode* is one of ``'r'`` for read-only (record) access, ``'w'`` for
+   write-only (playback) access and ``'rw'`` for both. Since many sound cards
+   only allow one process to have the recorder or player open at a time, it is a
+   good idea to open the device only for the activity needed.  Further, some
+   sound cards are half-duplex: they can be opened for reading or writing, but
+   not both at once.
+
+   Note the unusual calling syntax: the *first* argument is optional, and the
+   second is required.  This is a historical artifact for compatibility with the
+   older :mod:`linuxaudiodev` module which :mod:`ossaudiodev` supersedes.
+
+   .. % XXX it might also be motivated
+   .. % by my unfounded-but-still-possibly-true belief that the default
+   .. % audio device varies unpredictably across operating systems.  -GW
+
+
+.. function:: openmixer([device])
+
+   Open a mixer device and return an OSS mixer device object.   *device* is the
+   mixer device filename to use.  If it is not specified, this module first looks
+   in the environment variable :envvar:`MIXERDEV` for a device to use.  If not
+   found, it falls back to :file:`/dev/mixer`.
+
+
+.. _ossaudio-device-objects:
+
+Audio Device Objects
+--------------------
+
+Before you can write to or read from an audio device, you must call three
+methods in the correct order:
+
+#. :meth:`setfmt` to set the output format
+
+#. :meth:`channels` to set the number of channels
+
+#. :meth:`speed` to set the sample rate
+
+Alternately, you can use the :meth:`setparameters` method to set all three audio
+parameters at once.  This is more convenient, but may not be as flexible in all
+cases.
+
+The audio device objects returned by :func:`open` define the following methods
+and (read-only) attributes:
+
+
+.. method:: oss_audio_device.close()
+
+   Explicitly close the audio device.  When you are done writing to or reading from
+   an audio device, you should explicitly close it.  A closed device cannot be used
+   again.
+
+
+.. method:: oss_audio_device.fileno()
+
+   Return the file descriptor associated with the device.
+
+
+.. method:: oss_audio_device.read(size)
+
+   Read *size* bytes from the audio input and return them as a Python string.
+   Unlike most Unix device drivers, OSS audio devices in blocking mode (the
+   default) will block :func:`read` until the entire requested amount of data is
+   available.
+
+
+.. method:: oss_audio_device.write(data)
+
+   Write the Python string *data* to the audio device and return the number of
+   bytes written.  If the audio device is in blocking mode (the default), the
+   entire string is always written (again, this is different from usual Unix device
+   semantics).  If the device is in non-blocking mode, some data may not be written
+   ---see :meth:`writeall`.
+
+
+.. method:: oss_audio_device.writeall(data)
+
+   Write the entire Python string *data* to the audio device: waits until the audio
+   device is able to accept data, writes as much data as it will accept, and
+   repeats until *data* has been completely written. If the device is in blocking
+   mode (the default), this has the same effect as :meth:`write`; :meth:`writeall`
+   is only useful in non-blocking mode.  Has no return value, since the amount of
+   data written is always equal to the amount of data supplied.
+
+The following methods each map to exactly one :func:`ioctl` system call.  The
+correspondence is obvious: for example, :meth:`setfmt` corresponds to the
+``SNDCTL_DSP_SETFMT`` ioctl, and :meth:`sync` to ``SNDCTL_DSP_SYNC`` (this can
+be useful when consulting the OSS documentation).  If the underlying
+:func:`ioctl` fails, they all raise :exc:`IOError`.
+
+
+.. method:: oss_audio_device.nonblock()
+
+   Put the device into non-blocking mode.  Once in non-blocking mode, there is no
+   way to return it to blocking mode.
+
+
+.. method:: oss_audio_device.getfmts()
+
+   Return a bitmask of the audio output formats supported by the soundcard.  Some
+   of the formats supported by OSS are:
+
+   +-------------------------+---------------------------------------------+
+   | Format                  | Description                                 |
+   +=========================+=============================================+
+   | :const:`AFMT_MU_LAW`    | a logarithmic encoding (used by Sun ``.au`` |
+   |                         | files and :file:`/dev/audio`)               |
+   +-------------------------+---------------------------------------------+
+   | :const:`AFMT_A_LAW`     | a logarithmic encoding                      |
+   +-------------------------+---------------------------------------------+
+   | :const:`AFMT_IMA_ADPCM` | a 4:1 compressed format defined by the      |
+   |                         | Interactive Multimedia Association          |
+   +-------------------------+---------------------------------------------+
+   | :const:`AFMT_U8`        | Unsigned, 8-bit audio                       |
+   +-------------------------+---------------------------------------------+
+   | :const:`AFMT_S16_LE`    | Signed, 16-bit audio, little-endian byte    |
+   |                         | order (as used by Intel processors)         |
+   +-------------------------+---------------------------------------------+
+   | :const:`AFMT_S16_BE`    | Signed, 16-bit audio, big-endian byte order |
+   |                         | (as used by 68k, PowerPC, Sparc)            |
+   +-------------------------+---------------------------------------------+
+   | :const:`AFMT_S8`        | Signed, 8 bit audio                         |
+   +-------------------------+---------------------------------------------+
+   | :const:`AFMT_U16_LE`    | Unsigned, 16-bit little-endian audio        |
+   +-------------------------+---------------------------------------------+
+   | :const:`AFMT_U16_BE`    | Unsigned, 16-bit big-endian audio           |
+   +-------------------------+---------------------------------------------+
+
+   Consult the OSS documentation for a full list of audio formats, and note that
+   most devices support only a subset of these formats.  Some older devices only
+   support :const:`AFMT_U8`; the most common format used today is
+   :const:`AFMT_S16_LE`.
+
+
+.. method:: oss_audio_device.setfmt(format)
+
+   Try to set the current audio format to *format*---see :meth:`getfmts` for a
+   list.  Returns the audio format that the device was set to, which may not be the
+   requested format.  May also be used to return the current audio format---do this
+   by passing an "audio format" of :const:`AFMT_QUERY`.
+
+
+.. method:: oss_audio_device.channels(nchannels)
+
+   Set the number of output channels to *nchannels*.  A value of 1 indicates
+   monophonic sound, 2 stereophonic.  Some devices may have more than 2 channels,
+   and some high-end devices may not support mono. Returns the number of channels
+   the device was set to.
+
+
+.. method:: oss_audio_device.speed(samplerate)
+
+   Try to set the audio sampling rate to *samplerate* samples per second.  Returns
+   the rate actually set.  Most sound devices don't support arbitrary sampling
+   rates.  Common rates are:
+
+   +-------+-------------------------------------------+
+   | Rate  | Description                               |
+   +=======+===========================================+
+   | 8000  | default rate for :file:`/dev/audio`       |
+   +-------+-------------------------------------------+
+   | 11025 | speech recording                          |
+   +-------+-------------------------------------------+
+   | 22050 |                                           |
+   +-------+-------------------------------------------+
+   | 44100 | CD quality audio (at 16 bits/sample and 2 |
+   |       | channels)                                 |
+   +-------+-------------------------------------------+
+   | 96000 | DVD quality audio (at 24 bits/sample)     |
+   +-------+-------------------------------------------+
+
+
+.. method:: oss_audio_device.sync()
+
+   Wait until the sound device has played every byte in its buffer.  (This happens
+   implicitly when the device is closed.)  The OSS documentation recommends closing
+   and re-opening the device rather than using :meth:`sync`.
+
+
+.. method:: oss_audio_device.reset()
+
+   Immediately stop playing or recording and return the device to a state where it
+   can accept commands.  The OSS documentation recommends closing and re-opening
+   the device after calling :meth:`reset`.
+
+
+.. method:: oss_audio_device.post()
+
+   Tell the driver that there is likely to be a pause in the output, making it
+   possible for the device to handle the pause more intelligently.  You might use
+   this after playing a spot sound effect, before waiting for user input, or before
+   doing disk I/O.
+
+The following convenience methods combine several ioctls, or one ioctl and some
+simple calculations.
+
+
+.. method:: oss_audio_device.setparameters(format, nchannels, samplerate [, strict=False])
+
+   Set the key audio sampling parameters---sample format, number of channels, and
+   sampling rate---in one method call.  *format*,  *nchannels*, and *samplerate*
+   should be as specified in the :meth:`setfmt`, :meth:`channels`, and
+   :meth:`speed`  methods.  If *strict* is true, :meth:`setparameters` checks to
+   see if each parameter was actually set to the requested value, and raises
+   :exc:`OSSAudioError` if not.  Returns a tuple (*format*, *nchannels*,
+   *samplerate*) indicating the parameter values that were actually set by the
+   device driver (i.e., the same as the return values of :meth:`setfmt`,
+   :meth:`channels`, and :meth:`speed`).
+
+   For example,  ::
+
+      (fmt, channels, rate) = dsp.setparameters(fmt, channels, rate)
+
+   is equivalent to  ::
+
+      fmt = dsp.setfmt(fmt)
+      channels = dsp.channels(channels)
+      rate = dsp.rate(channels)
+
+
+.. method:: oss_audio_device.bufsize()
+
+   Returns the size of the hardware buffer, in samples.
+
+
+.. method:: oss_audio_device.obufcount()
+
+   Returns the number of samples that are in the hardware buffer yet to be played.
+
+
+.. method:: oss_audio_device.obuffree()
+
+   Returns the number of samples that could be queued into the hardware buffer to
+   be played without blocking.
+
+Audio device objects also support several read-only attributes:
+
+
+.. attribute:: oss_audio_device.closed
+
+   Boolean indicating whether the device has been closed.
+
+
+.. attribute:: oss_audio_device.name
+
+   String containing the name of the device file.
+
+
+.. attribute:: oss_audio_device.mode
+
+   The I/O mode for the file, either ``"r"``, ``"rw"``, or ``"w"``.
+
+
+.. _mixer-device-objects:
+
+Mixer Device Objects
+--------------------
+
+The mixer object provides two file-like methods:
+
+
+.. method:: oss_mixer_device.close()
+
+   This method closes the open mixer device file.  Any further attempts to use the
+   mixer after this file is closed will raise an :exc:`IOError`.
+
+
+.. method:: oss_mixer_device.fileno()
+
+   Returns the file handle number of the open mixer device file.
+
+The remaining methods are specific to audio mixing:
+
+
+.. method:: oss_mixer_device.controls()
+
+   This method returns a bitmask specifying the available mixer controls ("Control"
+   being a specific mixable "channel", such as :const:`SOUND_MIXER_PCM` or
+   :const:`SOUND_MIXER_SYNTH`).  This bitmask indicates a subset of all available
+   mixer controls---the :const:`SOUND_MIXER_\*` constants defined at module level.
+   To determine if, for example, the current mixer object supports a PCM mixer, use
+   the following Python code::
+
+      mixer=ossaudiodev.openmixer()
+      if mixer.controls() & (1 << ossaudiodev.SOUND_MIXER_PCM):
+          # PCM is supported
+          ... code ...
+
+   For most purposes, the :const:`SOUND_MIXER_VOLUME` (master volume) and
+   :const:`SOUND_MIXER_PCM` controls should suffice---but code that uses the mixer
+   should be flexible when it comes to choosing mixer controls.  On the Gravis
+   Ultrasound, for example, :const:`SOUND_MIXER_VOLUME` does not exist.
+
+
+.. method:: oss_mixer_device.stereocontrols()
+
+   Returns a bitmask indicating stereo mixer controls.  If a bit is set, the
+   corresponding control is stereo; if it is unset, the control is either
+   monophonic or not supported by the mixer (use in combination with
+   :meth:`controls` to determine which).
+
+   See the code example for the :meth:`controls` function for an example of getting
+   data from a bitmask.
+
+
+.. method:: oss_mixer_device.reccontrols()
+
+   Returns a bitmask specifying the mixer controls that may be used to record.  See
+   the code example for :meth:`controls` for an example of reading from a bitmask.
+
+
+.. method:: oss_mixer_device.get(control)
+
+   Returns the volume of a given mixer control.  The returned volume is a 2-tuple
+   ``(left_volume,right_volume)``.  Volumes are specified as numbers from 0
+   (silent) to 100 (full volume).  If the control is monophonic, a 2-tuple is still
+   returned, but both volumes are the same.
+
+   Raises :exc:`OSSAudioError` if an invalid control was is specified, or
+   :exc:`IOError` if an unsupported control is specified.
+
+
+.. method:: oss_mixer_device.set(control, (left, right))
+
+   Sets the volume for a given mixer control to ``(left,right)``. ``left`` and
+   ``right`` must be ints and between 0 (silent) and 100 (full volume).  On
+   success, the new volume is returned as a 2-tuple. Note that this may not be
+   exactly the same as the volume specified, because of the limited resolution of
+   some soundcard's mixers.
+
+   Raises :exc:`OSSAudioError` if an invalid mixer control was specified, or if the
+   specified volumes were out-of-range.
+
+
+.. method:: oss_mixer_device.get_recsrc()
+
+   This method returns a bitmask indicating which control(s) are currently being
+   used as a recording source.
+
+
+.. method:: oss_mixer_device.set_recsrc(bitmask)
+
+   Call this function to specify a recording source.  Returns a bitmask indicating
+   the new recording source (or sources) if successful; raises :exc:`IOError` if an
+   invalid source was specified.  To set the current recording source to the
+   microphone input::
+
+      mixer.setrecsrc (1 << ossaudiodev.SOUND_MIXER_MIC)
+
diff --git a/Doc/library/othergui.rst b/Doc/library/othergui.rst
new file mode 100644
index 0000000..aadb74d
--- /dev/null
+++ b/Doc/library/othergui.rst
@@ -0,0 +1,84 @@
+.. _other-gui-packages:
+
+Other Graphical User Interface Packages
+=======================================
+
+There are an number of extension widget sets to :mod:`Tkinter`.
+
+
+.. seealso::
+
+   `Python megawidgets `_
+      is a toolkit for building high-level compound widgets in Python using the
+      :mod:`Tkinter` module.  It consists of a set of base classes and a library of
+      flexible and extensible megawidgets built on this foundation. These megawidgets
+      include notebooks, comboboxes, selection widgets, paned widgets, scrolled
+      widgets, dialog windows, etc.  Also, with the Pmw.Blt interface to BLT, the
+      busy, graph, stripchart, tabset and vector commands are be available.
+
+      The initial ideas for Pmw were taken from the Tk ``itcl`` extensions ``[incr
+      Tk]`` by Michael McLennan and ``[incr Widgets]`` by Mark Ulferts. Several of the
+      megawidgets are direct translations from the itcl to Python. It offers most of
+      the range of widgets that ``[incr Widgets]`` does, and is almost as complete as
+      Tix, lacking however Tix's fast :class:`HList` widget for drawing trees.
+
+   `Tkinter3000 Widget Construction Kit (WCK) `_
+      is a library that allows you to write new Tkinter widgets in pure Python.  The
+      WCK framework gives you full control over widget creation, configuration, screen
+      appearance, and event handling.  WCK widgets can be very fast and light-weight,
+      since they can operate directly on Python data structures, without having to
+      transfer data through the Tk/Tcl layer.
+
+      .. % 
+
+The major cross-platform (Windows, Mac OS X, Unix-like) GUI toolkits that are
+also available for Python:
+
+
+.. seealso::
+
+   `PyGTK `_
+      is a set of bindings for the `GTK `_ widget set. It
+      provides an object oriented interface that is slightly higher level than the C
+      one. It comes with many more widgets than Tkinter provides, and
+      has good Python-specific reference documentation. There are also `bindings
+      `_ to  `GNOME `_.
+      One well known PyGTK application is
+      `PythonCAD `_. An
+      online `tutorial `_ is
+      available.
+
+   `PyQt `_
+      PyQt is a :program:`sip`\ -wrapped binding to the Qt toolkit.  Qt is an
+      extensive C++ GUI application development framework that is
+      available for Unix, Windows and Mac OS X. :program:`sip` is a tool
+      for generating bindings for C++ libraries as Python classes, and
+      is specifically designed for Python. The *PyQt3* bindings have a
+      book, `GUI Programming with Python: QT Edition
+      `_ by Boudewijn
+      Rempt. The *PyQt4* bindings also have a book, `Rapid GUI Programming
+      with Python and Qt `_, by Mark
+      Summerfield.
+
+   `wxPython `_
+      wxPython is a cross-platform GUI toolkit for Python that is built around
+      the popular `wxWidgets `_ (formerly wxWindows)
+      C++ toolkit.  It provides a native look and feel for applications on
+      Windows, Mac OS X, and Unix systems by using each platform's native
+      widgets where ever possible, (GTK+ on Unix-like systems).  In addition to
+      an extensive set of widgets, wxPython provides classes for online
+      documentation and context sensitive help, printing, HTML viewing,
+      low-level device context drawing, drag and drop, system clipboard access,
+      an XML-based resource format and more, including an ever growing library
+      of user-contributed modules.  wxPython has a book, `wxPython in Action
+      `_, by Noel Rappin and
+      Robin Dunn.
+
+PyGTK, PyQt, and wxPython, all have a modern look and feel and far more
+widgets and better documentation than Tkinter. In addition,
+there are many other GUI toolkits for Python, both cross-platform, and
+platform-specific. See the `GUI Programming
+`_ page in the Python Wiki for a
+much more complete list, and also for links to documents where the
+different GUI toolkits are compared.
+
diff --git a/Doc/library/parser.rst b/Doc/library/parser.rst
new file mode 100644
index 0000000..b767561
--- /dev/null
+++ b/Doc/library/parser.rst
@@ -0,0 +1,683 @@
+
+:mod:`parser` --- Access Python parse trees
+===========================================
+
+.. module:: parser
+   :synopsis: Access parse trees for Python source code.
+.. moduleauthor:: Fred L. Drake, Jr. 
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+.. % Copyright 1995 Virginia Polytechnic Institute and State University
+.. % and Fred L. Drake, Jr.  This copyright notice must be distributed on
+.. % all copies, but this document otherwise may be distributed as part
+.. % of the Python distribution.  No fee may be charged for this document
+.. % in any representation, either on paper or electronically.  This
+.. % restriction does not affect other elements in a distributed package
+.. % in any way.
+
+.. index:: single: parsing; Python source code
+
+The :mod:`parser` module provides an interface to Python's internal parser and
+byte-code compiler.  The primary purpose for this interface is to allow Python
+code to edit the parse tree of a Python expression and create executable code
+from this.  This is better than trying to parse and modify an arbitrary Python
+code fragment as a string because parsing is performed in a manner identical to
+the code forming the application.  It is also faster.
+
+There are a few things to note about this module which are important to making
+use of the data structures created.  This is not a tutorial on editing the parse
+trees for Python code, but some examples of using the :mod:`parser` module are
+presented.
+
+Most importantly, a good understanding of the Python grammar processed by the
+internal parser is required.  For full information on the language syntax, refer
+to :ref:`reference-index`.  The parser
+itself is created from a grammar specification defined in the file
+:file:`Grammar/Grammar` in the standard Python distribution.  The parse trees
+stored in the AST objects created by this module are the actual output from the
+internal parser when created by the :func:`expr` or :func:`suite` functions,
+described below.  The AST objects created by :func:`sequence2ast` faithfully
+simulate those structures.  Be aware that the values of the sequences which are
+considered "correct" will vary from one version of Python to another as the
+formal grammar for the language is revised.  However, transporting code from one
+Python version to another as source text will always allow correct parse trees
+to be created in the target version, with the only restriction being that
+migrating to an older version of the interpreter will not support more recent
+language constructs.  The parse trees are not typically compatible from one
+version to another, whereas source code has always been forward-compatible.
+
+Each element of the sequences returned by :func:`ast2list` or :func:`ast2tuple`
+has a simple form.  Sequences representing non-terminal elements in the grammar
+always have a length greater than one.  The first element is an integer which
+identifies a production in the grammar.  These integers are given symbolic names
+in the C header file :file:`Include/graminit.h` and the Python module
+:mod:`symbol`.  Each additional element of the sequence represents a component
+of the production as recognized in the input string: these are always sequences
+which have the same form as the parent.  An important aspect of this structure
+which should be noted is that keywords used to identify the parent node type,
+such as the keyword :keyword:`if` in an :const:`if_stmt`, are included in the
+node tree without any special treatment.  For example, the :keyword:`if` keyword
+is represented by the tuple ``(1, 'if')``, where ``1`` is the numeric value
+associated with all :const:`NAME` tokens, including variable and function names
+defined by the user.  In an alternate form returned when line number information
+is requested, the same token might be represented as ``(1, 'if', 12)``, where
+the ``12`` represents the line number at which the terminal symbol was found.
+
+Terminal elements are represented in much the same way, but without any child
+elements and the addition of the source text which was identified.  The example
+of the :keyword:`if` keyword above is representative.  The various types of
+terminal symbols are defined in the C header file :file:`Include/token.h` and
+the Python module :mod:`token`.
+
+The AST objects are not required to support the functionality of this module,
+but are provided for three purposes: to allow an application to amortize the
+cost of processing complex parse trees, to provide a parse tree representation
+which conserves memory space when compared to the Python list or tuple
+representation, and to ease the creation of additional modules in C which
+manipulate parse trees.  A simple "wrapper" class may be created in Python to
+hide the use of AST objects.
+
+The :mod:`parser` module defines functions for a few distinct purposes.  The
+most important purposes are to create AST objects and to convert AST objects to
+other representations such as parse trees and compiled code objects, but there
+are also functions which serve to query the type of parse tree represented by an
+AST object.
+
+
+.. seealso::
+
+   Module :mod:`symbol`
+      Useful constants representing internal nodes of the parse tree.
+
+   Module :mod:`token`
+      Useful constants representing leaf nodes of the parse tree and functions for
+      testing node values.
+
+
+.. _creating-asts:
+
+Creating AST Objects
+--------------------
+
+AST objects may be created from source code or from a parse tree. When creating
+an AST object from source, different functions are used to create the ``'eval'``
+and ``'exec'`` forms.
+
+
+.. function:: expr(source)
+
+   The :func:`expr` function parses the parameter *source* as if it were an input
+   to ``compile(source, 'file.py', 'eval')``.  If the parse succeeds, an AST object
+   is created to hold the internal parse tree representation, otherwise an
+   appropriate exception is thrown.
+
+
+.. function:: suite(source)
+
+   The :func:`suite` function parses the parameter *source* as if it were an input
+   to ``compile(source, 'file.py', 'exec')``.  If the parse succeeds, an AST object
+   is created to hold the internal parse tree representation, otherwise an
+   appropriate exception is thrown.
+
+
+.. function:: sequence2ast(sequence)
+
+   This function accepts a parse tree represented as a sequence and builds an
+   internal representation if possible.  If it can validate that the tree conforms
+   to the Python grammar and all nodes are valid node types in the host version of
+   Python, an AST object is created from the internal representation and returned
+   to the called.  If there is a problem creating the internal representation, or
+   if the tree cannot be validated, a :exc:`ParserError` exception is thrown.  An
+   AST object created this way should not be assumed to compile correctly; normal
+   exceptions thrown by compilation may still be initiated when the AST object is
+   passed to :func:`compileast`.  This may indicate problems not related to syntax
+   (such as a :exc:`MemoryError` exception), but may also be due to constructs such
+   as the result of parsing ``del f(0)``, which escapes the Python parser but is
+   checked by the bytecode compiler.
+
+   Sequences representing terminal tokens may be represented as either two-element
+   lists of the form ``(1, 'name')`` or as three-element lists of the form ``(1,
+   'name', 56)``.  If the third element is present, it is assumed to be a valid
+   line number.  The line number may be specified for any subset of the terminal
+   symbols in the input tree.
+
+
+.. function:: tuple2ast(sequence)
+
+   This is the same function as :func:`sequence2ast`.  This entry point is
+   maintained for backward compatibility.
+
+
+.. _converting-asts:
+
+Converting AST Objects
+----------------------
+
+AST objects, regardless of the input used to create them, may be converted to
+parse trees represented as list- or tuple- trees, or may be compiled into
+executable code objects.  Parse trees may be extracted with or without line
+numbering information.
+
+
+.. function:: ast2list(ast[, line_info])
+
+   This function accepts an AST object from the caller in *ast* and returns a
+   Python list representing the equivalent parse tree.  The resulting list
+   representation can be used for inspection or the creation of a new parse tree in
+   list form.  This function does not fail so long as memory is available to build
+   the list representation.  If the parse tree will only be used for inspection,
+   :func:`ast2tuple` should be used instead to reduce memory consumption and
+   fragmentation.  When the list representation is required, this function is
+   significantly faster than retrieving a tuple representation and converting that
+   to nested lists.
+
+   If *line_info* is true, line number information will be included for all
+   terminal tokens as a third element of the list representing the token.  Note
+   that the line number provided specifies the line on which the token *ends*.
+   This information is omitted if the flag is false or omitted.
+
+
+.. function:: ast2tuple(ast[, line_info])
+
+   This function accepts an AST object from the caller in *ast* and returns a
+   Python tuple representing the equivalent parse tree.  Other than returning a
+   tuple instead of a list, this function is identical to :func:`ast2list`.
+
+   If *line_info* is true, line number information will be included for all
+   terminal tokens as a third element of the list representing the token.  This
+   information is omitted if the flag is false or omitted.
+
+
+.. function:: compileast(ast[, filename=''])
+
+   .. index::
+      builtin: exec
+      builtin: eval
+
+   The Python byte compiler can be invoked on an AST object to produce code objects
+   which can be used as part of a call to the built-in :func:`exec` or :func:`eval`
+   functions. This function provides the interface to the compiler, passing the
+   internal parse tree from *ast* to the parser, using the source file name
+   specified by the *filename* parameter. The default value supplied for *filename*
+   indicates that the source was an AST object.
+
+   Compiling an AST object may result in exceptions related to compilation; an
+   example would be a :exc:`SyntaxError` caused by the parse tree for ``del f(0)``:
+   this statement is considered legal within the formal grammar for Python but is
+   not a legal language construct.  The :exc:`SyntaxError` raised for this
+   condition is actually generated by the Python byte-compiler normally, which is
+   why it can be raised at this point by the :mod:`parser` module.  Most causes of
+   compilation failure can be diagnosed programmatically by inspection of the parse
+   tree.
+
+
+.. _querying-asts:
+
+Queries on AST Objects
+----------------------
+
+Two functions are provided which allow an application to determine if an AST was
+created as an expression or a suite.  Neither of these functions can be used to
+determine if an AST was created from source code via :func:`expr` or
+:func:`suite` or from a parse tree via :func:`sequence2ast`.
+
+
+.. function:: isexpr(ast)
+
+   .. index:: builtin: compile
+
+   When *ast* represents an ``'eval'`` form, this function returns true, otherwise
+   it returns false.  This is useful, since code objects normally cannot be queried
+   for this information using existing built-in functions.  Note that the code
+   objects created by :func:`compileast` cannot be queried like this either, and
+   are identical to those created by the built-in :func:`compile` function.
+
+
+.. function:: issuite(ast)
+
+   This function mirrors :func:`isexpr` in that it reports whether an AST object
+   represents an ``'exec'`` form, commonly known as a "suite."  It is not safe to
+   assume that this function is equivalent to ``not isexpr(ast)``, as additional
+   syntactic fragments may be supported in the future.
+
+
+.. _ast-errors:
+
+Exceptions and Error Handling
+-----------------------------
+
+The parser module defines a single exception, but may also pass other built-in
+exceptions from other portions of the Python runtime environment.  See each
+function for information about the exceptions it can raise.
+
+
+.. exception:: ParserError
+
+   Exception raised when a failure occurs within the parser module.  This is
+   generally produced for validation failures rather than the built in
+   :exc:`SyntaxError` thrown during normal parsing. The exception argument is
+   either a string describing the reason of the failure or a tuple containing a
+   sequence causing the failure from a parse tree passed to :func:`sequence2ast`
+   and an explanatory string.  Calls to :func:`sequence2ast` need to be able to
+   handle either type of exception, while calls to other functions in the module
+   will only need to be aware of the simple string values.
+
+Note that the functions :func:`compileast`, :func:`expr`, and :func:`suite` may
+throw exceptions which are normally thrown by the parsing and compilation
+process.  These include the built in exceptions :exc:`MemoryError`,
+:exc:`OverflowError`, :exc:`SyntaxError`, and :exc:`SystemError`.  In these
+cases, these exceptions carry all the meaning normally associated with them.
+Refer to the descriptions of each function for detailed information.
+
+
+.. _ast-objects:
+
+AST Objects
+-----------
+
+Ordered and equality comparisons are supported between AST objects. Pickling of
+AST objects (using the :mod:`pickle` module) is also supported.
+
+
+.. data:: ASTType
+
+   The type of the objects returned by :func:`expr`, :func:`suite` and
+   :func:`sequence2ast`.
+
+AST objects have the following methods:
+
+
+.. method:: AST.compile([filename])
+
+   Same as ``compileast(ast, filename)``.
+
+
+.. method:: AST.isexpr()
+
+   Same as ``isexpr(ast)``.
+
+
+.. method:: AST.issuite()
+
+   Same as ``issuite(ast)``.
+
+
+.. method:: AST.tolist([line_info])
+
+   Same as ``ast2list(ast, line_info)``.
+
+
+.. method:: AST.totuple([line_info])
+
+   Same as ``ast2tuple(ast, line_info)``.
+
+
+.. _ast-examples:
+
+Examples
+--------
+
+.. index:: builtin: compile
+
+The parser modules allows operations to be performed on the parse tree of Python
+source code before the bytecode is generated, and provides for inspection of the
+parse tree for information gathering purposes. Two examples are presented.  The
+simple example demonstrates emulation of the :func:`compile` built-in function
+and the complex example shows the use of a parse tree for information discovery.
+
+
+Emulation of :func:`compile`
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+While many useful operations may take place between parsing and bytecode
+generation, the simplest operation is to do nothing.  For this purpose, using
+the :mod:`parser` module to produce an intermediate data structure is equivalent
+to the code ::
+
+   >>> code = compile('a + 5', 'file.py', 'eval')
+   >>> a = 5
+   >>> eval(code)
+   10
+
+The equivalent operation using the :mod:`parser` module is somewhat longer, and
+allows the intermediate internal parse tree to be retained as an AST object::
+
+   >>> import parser
+   >>> ast = parser.expr('a + 5')
+   >>> code = ast.compile('file.py')
+   >>> a = 5
+   >>> eval(code)
+   10
+
+An application which needs both AST and code objects can package this code into
+readily available functions::
+
+   import parser
+
+   def load_suite(source_string):
+       ast = parser.suite(source_string)
+       return ast, ast.compile()
+
+   def load_expression(source_string):
+       ast = parser.expr(source_string)
+       return ast, ast.compile()
+
+
+Information Discovery
+^^^^^^^^^^^^^^^^^^^^^
+
+.. index::
+   single: string; documentation
+   single: docstrings
+
+Some applications benefit from direct access to the parse tree.  The remainder
+of this section demonstrates how the parse tree provides access to module
+documentation defined in docstrings without requiring that the code being
+examined be loaded into a running interpreter via :keyword:`import`.  This can
+be very useful for performing analyses of untrusted code.
+
+Generally, the example will demonstrate how the parse tree may be traversed to
+distill interesting information.  Two functions and a set of classes are
+developed which provide programmatic access to high level function and class
+definitions provided by a module.  The classes extract information from the
+parse tree and provide access to the information at a useful semantic level, one
+function provides a simple low-level pattern matching capability, and the other
+function defines a high-level interface to the classes by handling file
+operations on behalf of the caller.  All source files mentioned here which are
+not part of the Python installation are located in the :file:`Demo/parser/`
+directory of the distribution.
+
+The dynamic nature of Python allows the programmer a great deal of flexibility,
+but most modules need only a limited measure of this when defining classes,
+functions, and methods.  In this example, the only definitions that will be
+considered are those which are defined in the top level of their context, e.g.,
+a function defined by a :keyword:`def` statement at column zero of a module, but
+not a function defined within a branch of an :keyword:`if` ... :keyword:`else`
+construct, though there are some good reasons for doing so in some situations.
+Nesting of definitions will be handled by the code developed in the example.
+
+To construct the upper-level extraction methods, we need to know what the parse
+tree structure looks like and how much of it we actually need to be concerned
+about.  Python uses a moderately deep parse tree so there are a large number of
+intermediate nodes.  It is important to read and understand the formal grammar
+used by Python.  This is specified in the file :file:`Grammar/Grammar` in the
+distribution. Consider the simplest case of interest when searching for
+docstrings: a module consisting of a docstring and nothing else.  (See file
+:file:`docstring.py`.) ::
+
+   """Some documentation.
+   """
+
+Using the interpreter to take a look at the parse tree, we find a bewildering
+mass of numbers and parentheses, with the documentation buried deep in nested
+tuples. ::
+
+   >>> import parser
+   >>> import pprint
+   >>> ast = parser.suite(open('docstring.py').read())
+   >>> tup = ast.totuple()
+   >>> pprint.pprint(tup)
+   (257,
+    (264,
+     (265,
+      (266,
+       (267,
+        (307,
+         (287,
+          (288,
+           (289,
+            (290,
+             (292,
+              (293,
+               (294,
+                (295,
+                 (296,
+                  (297,
+                   (298,
+                    (299,
+                     (300, (3, '"""Some documentation.\n"""'))))))))))))))))),
+      (4, ''))),
+    (4, ''),
+    (0, ''))
+
+The numbers at the first element of each node in the tree are the node types;
+they map directly to terminal and non-terminal symbols in the grammar.
+Unfortunately, they are represented as integers in the internal representation,
+and the Python structures generated do not change that.  However, the
+:mod:`symbol` and :mod:`token` modules provide symbolic names for the node types
+and dictionaries which map from the integers to the symbolic names for the node
+types.
+
+In the output presented above, the outermost tuple contains four elements: the
+integer ``257`` and three additional tuples.  Node type ``257`` has the symbolic
+name :const:`file_input`.  Each of these inner tuples contains an integer as the
+first element; these integers, ``264``, ``4``, and ``0``, represent the node
+types :const:`stmt`, :const:`NEWLINE`, and :const:`ENDMARKER`, respectively.
+Note that these values may change depending on the version of Python you are
+using; consult :file:`symbol.py` and :file:`token.py` for details of the
+mapping.  It should be fairly clear that the outermost node is related primarily
+to the input source rather than the contents of the file, and may be disregarded
+for the moment.  The :const:`stmt` node is much more interesting.  In
+particular, all docstrings are found in subtrees which are formed exactly as
+this node is formed, with the only difference being the string itself.  The
+association between the docstring in a similar tree and the defined entity
+(class, function, or module) which it describes is given by the position of the
+docstring subtree within the tree defining the described structure.
+
+By replacing the actual docstring with something to signify a variable component
+of the tree, we allow a simple pattern matching approach to check any given
+subtree for equivalence to the general pattern for docstrings.  Since the
+example demonstrates information extraction, we can safely require that the tree
+be in tuple form rather than list form, allowing a simple variable
+representation to be ``['variable_name']``.  A simple recursive function can
+implement the pattern matching, returning a Boolean and a dictionary of variable
+name to value mappings.  (See file :file:`example.py`.) ::
+
+   from types import ListType, TupleType
+
+   def match(pattern, data, vars=None):
+       if vars is None:
+           vars = {}
+       if type(pattern) is ListType:
+           vars[pattern[0]] = data
+           return 1, vars
+       if type(pattern) is not TupleType:
+           return (pattern == data), vars
+       if len(data) != len(pattern):
+           return 0, vars
+       for pattern, data in map(None, pattern, data):
+           same, vars = match(pattern, data, vars)
+           if not same:
+               break
+       return same, vars
+
+Using this simple representation for syntactic variables and the symbolic node
+types, the pattern for the candidate docstring subtrees becomes fairly readable.
+(See file :file:`example.py`.) ::
+
+   import symbol
+   import token
+
+   DOCSTRING_STMT_PATTERN = (
+       symbol.stmt,
+       (symbol.simple_stmt,
+        (symbol.small_stmt,
+         (symbol.expr_stmt,
+          (symbol.testlist,
+           (symbol.test,
+            (symbol.and_test,
+             (symbol.not_test,
+              (symbol.comparison,
+               (symbol.expr,
+                (symbol.xor_expr,
+                 (symbol.and_expr,
+                  (symbol.shift_expr,
+                   (symbol.arith_expr,
+                    (symbol.term,
+                     (symbol.factor,
+                      (symbol.power,
+                       (symbol.atom,
+                        (token.STRING, ['docstring'])
+                        )))))))))))))))),
+        (token.NEWLINE, '')
+        ))
+
+Using the :func:`match` function with this pattern, extracting the module
+docstring from the parse tree created previously is easy::
+
+   >>> found, vars = match(DOCSTRING_STMT_PATTERN, tup[1])
+   >>> found
+   1
+   >>> vars
+   {'docstring': '"""Some documentation.\n"""'}
+
+Once specific data can be extracted from a location where it is expected, the
+question of where information can be expected needs to be answered.  When
+dealing with docstrings, the answer is fairly simple: the docstring is the first
+:const:`stmt` node in a code block (:const:`file_input` or :const:`suite` node
+types).  A module consists of a single :const:`file_input` node, and class and
+function definitions each contain exactly one :const:`suite` node.  Classes and
+functions are readily identified as subtrees of code block nodes which start
+with ``(stmt, (compound_stmt, (classdef, ...`` or ``(stmt, (compound_stmt,
+(funcdef, ...``.  Note that these subtrees cannot be matched by :func:`match`
+since it does not support multiple sibling nodes to match without regard to
+number.  A more elaborate matching function could be used to overcome this
+limitation, but this is sufficient for the example.
+
+Given the ability to determine whether a statement might be a docstring and
+extract the actual string from the statement, some work needs to be performed to
+walk the parse tree for an entire module and extract information about the names
+defined in each context of the module and associate any docstrings with the
+names.  The code to perform this work is not complicated, but bears some
+explanation.
+
+The public interface to the classes is straightforward and should probably be
+somewhat more flexible.  Each "major" block of the module is described by an
+object providing several methods for inquiry and a constructor which accepts at
+least the subtree of the complete parse tree which it represents.  The
+:class:`ModuleInfo` constructor accepts an optional *name* parameter since it
+cannot otherwise determine the name of the module.
+
+The public classes include :class:`ClassInfo`, :class:`FunctionInfo`, and
+:class:`ModuleInfo`.  All objects provide the methods :meth:`get_name`,
+:meth:`get_docstring`, :meth:`get_class_names`, and :meth:`get_class_info`.  The
+:class:`ClassInfo` objects support :meth:`get_method_names` and
+:meth:`get_method_info` while the other classes provide
+:meth:`get_function_names` and :meth:`get_function_info`.
+
+Within each of the forms of code block that the public classes represent, most
+of the required information is in the same form and is accessed in the same way,
+with classes having the distinction that functions defined at the top level are
+referred to as "methods." Since the difference in nomenclature reflects a real
+semantic distinction from functions defined outside of a class, the
+implementation needs to maintain the distinction. Hence, most of the
+functionality of the public classes can be implemented in a common base class,
+:class:`SuiteInfoBase`, with the accessors for function and method information
+provided elsewhere. Note that there is only one class which represents function
+and method information; this parallels the use of the :keyword:`def` statement
+to define both types of elements.
+
+Most of the accessor functions are declared in :class:`SuiteInfoBase` and do not
+need to be overridden by subclasses.  More importantly, the extraction of most
+information from a parse tree is handled through a method called by the
+:class:`SuiteInfoBase` constructor.  The example code for most of the classes is
+clear when read alongside the formal grammar, but the method which recursively
+creates new information objects requires further examination.  Here is the
+relevant part of the :class:`SuiteInfoBase` definition from :file:`example.py`::
+
+   class SuiteInfoBase:
+       _docstring = ''
+       _name = ''
+
+       def __init__(self, tree = None):
+           self._class_info = {}
+           self._function_info = {}
+           if tree:
+               self._extract_info(tree)
+
+       def _extract_info(self, tree):
+           # extract docstring
+           if len(tree) == 2:
+               found, vars = match(DOCSTRING_STMT_PATTERN[1], tree[1])
+           else:
+               found, vars = match(DOCSTRING_STMT_PATTERN, tree[3])
+           if found:
+               self._docstring = eval(vars['docstring'])
+           # discover inner definitions
+           for node in tree[1:]:
+               found, vars = match(COMPOUND_STMT_PATTERN, node)
+               if found:
+                   cstmt = vars['compound']
+                   if cstmt[0] == symbol.funcdef:
+                       name = cstmt[2][1]
+                       self._function_info[name] = FunctionInfo(cstmt)
+                   elif cstmt[0] == symbol.classdef:
+                       name = cstmt[2][1]
+                       self._class_info[name] = ClassInfo(cstmt)
+
+After initializing some internal state, the constructor calls the
+:meth:`_extract_info` method.  This method performs the bulk of the information
+extraction which takes place in the entire example.  The extraction has two
+distinct phases: the location of the docstring for the parse tree passed in, and
+the discovery of additional definitions within the code block represented by the
+parse tree.
+
+The initial :keyword:`if` test determines whether the nested suite is of the
+"short form" or the "long form."  The short form is used when the code block is
+on the same line as the definition of the code block, as in ::
+
+   def square(x): "Square an argument."; return x ** 2
+
+while the long form uses an indented block and allows nested definitions::
+
+   def make_power(exp):
+       "Make a function that raises an argument to the exponent `exp'."
+       def raiser(x, y=exp):
+           return x ** y
+       return raiser
+
+When the short form is used, the code block may contain a docstring as the
+first, and possibly only, :const:`small_stmt` element.  The extraction of such a
+docstring is slightly different and requires only a portion of the complete
+pattern used in the more common case.  As implemented, the docstring will only
+be found if there is only one :const:`small_stmt` node in the
+:const:`simple_stmt` node. Since most functions and methods which use the short
+form do not provide a docstring, this may be considered sufficient.  The
+extraction of the docstring proceeds using the :func:`match` function as
+described above, and the value of the docstring is stored as an attribute of the
+:class:`SuiteInfoBase` object.
+
+After docstring extraction, a simple definition discovery algorithm operates on
+the :const:`stmt` nodes of the :const:`suite` node.  The special case of the
+short form is not tested; since there are no :const:`stmt` nodes in the short
+form, the algorithm will silently skip the single :const:`simple_stmt` node and
+correctly not discover any nested definitions.
+
+Each statement in the code block is categorized as a class definition, function
+or method definition, or something else.  For the definition statements, the
+name of the element defined is extracted and a representation object appropriate
+to the definition is created with the defining subtree passed as an argument to
+the constructor.  The representation objects are stored in instance variables
+and may be retrieved by name using the appropriate accessor methods.
+
+The public classes provide any accessors required which are more specific than
+those provided by the :class:`SuiteInfoBase` class, but the real extraction
+algorithm remains common to all forms of code blocks.  A high-level function can
+be used to extract the complete set of information from a source file.  (See
+file :file:`example.py`.) ::
+
+   def get_docs(fileName):
+       import os
+       import parser
+
+       source = open(fileName).read()
+       basename = os.path.basename(os.path.splitext(fileName)[0])
+       ast = parser.suite(source)
+       return ModuleInfo(ast.totuple(), basename)
+
+This provides an easy-to-use interface to the documentation of a module.  If
+information is required which is not extracted by the code of this example, the
+code may be extended at clearly defined points to provide additional
+capabilities.
+
diff --git a/Doc/library/pdb.rst b/Doc/library/pdb.rst
new file mode 100644
index 0000000..804dd23
--- /dev/null
+++ b/Doc/library/pdb.rst
@@ -0,0 +1,409 @@
+
+.. _debugger:
+
+*******************
+The Python Debugger
+*******************
+
+.. module:: pdb
+   :synopsis: The Python debugger for interactive interpreters.
+
+
+.. index:: single: debugging
+
+The module :mod:`pdb` defines an interactive source code debugger for Python
+programs.  It supports setting (conditional) breakpoints and single stepping at
+the source line level, inspection of stack frames, source code listing, and
+evaluation of arbitrary Python code in the context of any stack frame.  It also
+supports post-mortem debugging and can be called under program control.
+
+.. index::
+   single: Pdb (class in pdb)
+   module: bdb
+   module: cmd
+
+The debugger is extensible --- it is actually defined as the class :class:`Pdb`.
+This is currently undocumented but easily understood by reading the source.  The
+extension interface uses the modules :mod:`bdb` (undocumented) and :mod:`cmd`.
+
+The debugger's prompt is ``(Pdb)``. Typical usage to run a program under control
+of the debugger is::
+
+   >>> import pdb
+   >>> import mymodule
+   >>> pdb.run('mymodule.test()')
+   > (0)?()
+   (Pdb) continue
+   > (1)?()
+   (Pdb) continue
+   NameError: 'spam'
+   > (1)?()
+   (Pdb) 
+
+:file:`pdb.py` can also be invoked as a script to debug other scripts.  For
+example::
+
+   python -m pdb myscript.py
+
+When invoked as a script, pdb will automatically enter post-mortem debugging if
+the program being debugged exits abnormally. After post-mortem debugging (or
+after normal exit of the program), pdb will restart the program. Automatic
+restarting preserves pdb's state (such as breakpoints) and in most cases is more
+useful than quitting the debugger upon program's exit.
+
+.. versionadded:: 2.4
+   Restarting post-mortem behavior added.
+
+Typical usage to inspect a crashed program is::
+
+   >>> import pdb
+   >>> import mymodule
+   >>> mymodule.test()
+   Traceback (most recent call last):
+     File "", line 1, in ?
+     File "./mymodule.py", line 4, in test
+       test2()
+     File "./mymodule.py", line 3, in test2
+       print spam
+   NameError: spam
+   >>> pdb.pm()
+   > ./mymodule.py(3)test2()
+   -> print spam
+   (Pdb) 
+
+The module defines the following functions; each enters the debugger in a
+slightly different way:
+
+
+.. function:: run(statement[, globals[, locals]])
+
+   Execute the *statement* (given as a string) under debugger control.  The
+   debugger prompt appears before any code is executed; you can set breakpoints and
+   type ``continue``, or you can step through the statement using ``step`` or
+   ``next`` (all these commands are explained below).  The optional *globals* and
+   *locals* arguments specify the environment in which the code is executed; by
+   default the dictionary of the module :mod:`__main__` is used.  (See the
+   explanation of the built-in :func:`exec` or :func:`eval` functions.)
+
+
+.. function:: runeval(expression[, globals[, locals]])
+
+   Evaluate the *expression* (given as a string) under debugger control.  When
+   :func:`runeval` returns, it returns the value of the expression.  Otherwise this
+   function is similar to :func:`run`.
+
+
+.. function:: runcall(function[, argument, ...])
+
+   Call the *function* (a function or method object, not a string) with the given
+   arguments.  When :func:`runcall` returns, it returns whatever the function call
+   returned.  The debugger prompt appears as soon as the function is entered.
+
+
+.. function:: set_trace()
+
+   Enter the debugger at the calling stack frame.  This is useful to hard-code a
+   breakpoint at a given point in a program, even if the code is not otherwise
+   being debugged (e.g. when an assertion fails).
+
+
+.. function:: post_mortem(traceback)
+
+   Enter post-mortem debugging of the given *traceback* object.
+
+
+.. function:: pm()
+
+   Enter post-mortem debugging of the traceback found in ``sys.last_traceback``.
+
+
+.. _debugger-commands:
+
+Debugger Commands
+=================
+
+The debugger recognizes the following commands.  Most commands can be
+abbreviated to one or two letters; e.g. ``h(elp)`` means that either ``h`` or
+``help`` can be used to enter the help command (but not ``he`` or ``hel``, nor
+``H`` or ``Help`` or ``HELP``).  Arguments to commands must be separated by
+whitespace (spaces or tabs).  Optional arguments are enclosed in square brackets
+(``[]``) in the command syntax; the square brackets must not be typed.
+Alternatives in the command syntax are separated by a vertical bar (``|``).
+
+Entering a blank line repeats the last command entered.  Exception: if the last
+command was a ``list`` command, the next 11 lines are listed.
+
+Commands that the debugger doesn't recognize are assumed to be Python statements
+and are executed in the context of the program being debugged.  Python
+statements can also be prefixed with an exclamation point (``!``).  This is a
+powerful way to inspect the program being debugged; it is even possible to
+change a variable or call a function.  When an exception occurs in such a
+statement, the exception name is printed but the debugger's state is not
+changed.
+
+Multiple commands may be entered on a single line, separated by ``;;``.  (A
+single ``;`` is not used as it is the separator for multiple commands in a line
+that is passed to the Python parser.) No intelligence is applied to separating
+the commands; the input is split at the first ``;;`` pair, even if it is in the
+middle of a quoted string.
+
+The debugger supports aliases.  Aliases can have parameters which allows one a
+certain level of adaptability to the context under examination.
+
+.. index::
+   pair: .pdbrc; file
+   triple: debugger; configuration; file
+
+If a file :file:`.pdbrc`  exists in the user's home directory or in the current
+directory, it is read in and executed as if it had been typed at the debugger
+prompt. This is particularly useful for aliases.  If both files exist, the one
+in the home directory is read first and aliases defined there can be overridden
+by the local file.
+
+h(elp) [*command*]
+   Without argument, print the list of available commands.  With a *command* as
+   argument, print help about that command.  ``help pdb`` displays the full
+   documentation file; if the environment variable :envvar:`PAGER` is defined, the
+   file is piped through that command instead.  Since the *command* argument must
+   be an identifier, ``help exec`` must be entered to get help on the ``!``
+   command.
+
+w(here)
+   Print a stack trace, with the most recent frame at the bottom.  An arrow
+   indicates the current frame, which determines the context of most commands.
+
+d(own)
+   Move the current frame one level down in the stack trace (to a newer frame).
+
+u(p)
+   Move the current frame one level up in the stack trace (to an older frame).
+
+b(reak) [[*filename*:]*lineno*``|``*function*[, *condition*]]
+   With a *lineno* argument, set a break there in the current file.  With a
+   *function* argument, set a break at the first executable statement within that
+   function. The line number may be prefixed with a filename and a colon, to
+   specify a breakpoint in another file (probably one that hasn't been loaded yet).
+   The file is searched on ``sys.path``. Note that each breakpoint is assigned a
+   number to which all the other breakpoint commands refer.
+
+   If a second argument is present, it is an expression which must evaluate to true
+   before the breakpoint is honored.
+
+   Without argument, list all breaks, including for each breakpoint, the number of
+   times that breakpoint has been hit, the current ignore count, and the associated
+   condition if any.
+
+tbreak [[*filename*:]*lineno*``|``*function*[, *condition*]]
+   Temporary breakpoint, which is removed automatically when it is first hit.  The
+   arguments are the same as break.
+
+cl(ear) [*bpnumber* [*bpnumber ...*]]
+   With a space separated list of breakpoint numbers, clear those breakpoints.
+   Without argument, clear all breaks (but first ask confirmation).
+
+disable [*bpnumber* [*bpnumber ...*]]
+   Disables the breakpoints given as a space separated list of breakpoint numbers.
+   Disabling a breakpoint means it cannot cause the program to stop execution, but
+   unlike clearing a breakpoint, it remains in the list of breakpoints and can be
+   (re-)enabled.
+
+enable [*bpnumber* [*bpnumber ...*]]
+   Enables the breakpoints specified.
+
+ignore *bpnumber* [*count*]
+   Sets the ignore count for the given breakpoint number.  If count is omitted, the
+   ignore count is set to 0.  A breakpoint becomes active when the ignore count is
+   zero.  When non-zero, the count is decremented each time the breakpoint is
+   reached and the breakpoint is not disabled and any associated condition
+   evaluates to true.
+
+condition *bpnumber* [*condition*]
+   Condition is an expression which must evaluate to true before the breakpoint is
+   honored.  If condition is absent, any existing condition is removed; i.e., the
+   breakpoint is made unconditional.
+
+commands [*bpnumber*]
+   Specify a list of commands for breakpoint number *bpnumber*.  The commands
+   themselves appear on the following lines.  Type a line containing just 'end' to
+   terminate the commands. An example::
+
+      (Pdb) commands 1
+      (com) print some_variable
+      (com) end
+      (Pdb)
+
+   To remove all commands from a breakpoint, type commands and follow it
+   immediately with  end; that is, give no commands.
+
+   With no *bpnumber* argument, commands refers to the last breakpoint set.
+
+   You can use breakpoint commands to start your program up again. Simply use the
+   continue command, or step, or any other command that resumes execution.
+
+   Specifying any command resuming execution (currently continue, step, next,
+   return, jump, quit and their abbreviations) terminates the command list (as if
+   that command was immediately followed by end). This is because any time you
+   resume execution (even with a simple next or step), you may encounter· another
+   breakpoint--which could have its own command list, leading to ambiguities about
+   which list to execute.
+
+   If you use the 'silent' command in the command list, the usual message about
+   stopping at a breakpoint is not printed.  This may be desirable for breakpoints
+   that are to print a specific message and then continue.  If none of the other
+   commands print anything, you see no sign that the breakpoint was reached.
+
+   .. versionadded:: 2.5
+
+s(tep)
+   Execute the current line, stop at the first possible occasion (either in a
+   function that is called or on the next line in the current function).
+
+n(ext)
+   Continue execution until the next line in the current function is reached or it
+   returns.  (The difference between ``next`` and ``step`` is that ``step`` stops
+   inside a called function, while ``next`` executes called functions at (nearly)
+   full speed, only stopping at the next line in the current function.)
+
+r(eturn)
+   Continue execution until the current function returns.
+
+c(ont(inue))
+   Continue execution, only stop when a breakpoint is encountered.
+
+j(ump) *lineno*
+   Set the next line that will be executed.  Only available in the bottom-most
+   frame.  This lets you jump back and execute code again, or jump forward to skip
+   code that you don't want to run.
+
+   It should be noted that not all jumps are allowed --- for instance it is not
+   possible to jump into the middle of a :keyword:`for` loop or out of a
+   :keyword:`finally` clause.
+
+l(ist) [*first*[, *last*]]
+   List source code for the current file.  Without arguments, list 11 lines around
+   the current line or continue the previous listing.  With one argument, list 11
+   lines around at that line.  With two arguments, list the given range; if the
+   second argument is less than the first, it is interpreted as a count.
+
+a(rgs)
+   Print the argument list of the current function.
+
+p *expression*
+   Evaluate the *expression* in the current context and print its value.
+
+   .. note::
+
+      ``print`` can also be used, but is not a debugger command --- this executes the
+      Python :keyword:`print` statement.
+
+pp *expression*
+   Like the ``p`` command, except the value of the expression is pretty-printed
+   using the :mod:`pprint` module.
+
+alias [*name* [command]]
+   Creates an alias called *name* that executes *command*.  The command must *not*
+   be enclosed in quotes.  Replaceable parameters can be indicated by ``%1``,
+   ``%2``, and so on, while ``%*`` is replaced by all the parameters.  If no
+   command is given, the current alias for *name* is shown. If no arguments are
+   given, all aliases are listed.
+
+   Aliases may be nested and can contain anything that can be legally typed at the
+   pdb prompt.  Note that internal pdb commands *can* be overridden by aliases.
+   Such a command is then hidden until the alias is removed.  Aliasing is
+   recursively applied to the first word of the command line; all other words in
+   the line are left alone.
+
+   As an example, here are two useful aliases (especially when placed in the
+   :file:`.pdbrc` file)::
+
+      #Print instance variables (usage "pi classInst")
+      alias pi for k in %1.__dict__.keys(): print "%1.",k,"=",%1.__dict__[k]
+      #Print instance variables in self
+      alias ps pi self
+
+unalias *name*
+   Deletes the specified alias.
+
+[!]*statement*
+   Execute the (one-line) *statement* in the context of the current stack frame.
+   The exclamation point can be omitted unless the first word of the statement
+   resembles a debugger command. To set a global variable, you can prefix the
+   assignment command with a ``global`` command on the same line, e.g.::
+
+      (Pdb) global list_options; list_options = ['-l']
+      (Pdb)
+
+run [*args* ...]
+   Restart the debugged python program. If an argument is supplied, it is splitted
+   with "shlex" and the result is used as the new sys.argv. History, breakpoints,
+   actions and debugger options are preserved. "restart" is an alias for "run".
+
+   .. versionadded:: 2.6
+
+q(uit)
+   Quit from the debugger. The program being executed is aborted.
+
+
+.. _debugger-hooks:
+
+How It Works
+============
+
+Some changes were made to the interpreter:
+
+* ``sys.settrace(func)`` sets the global trace function
+
+* there can also a local trace function (see later)
+
+Trace functions have three arguments: *frame*, *event*, and *arg*. *frame* is
+the current stack frame.  *event* is a string: ``'call'``, ``'line'``,
+``'return'``, ``'exception'``, ``'c_call'``, ``'c_return'``, or
+``'c_exception'``. *arg* depends on the event type.
+
+The global trace function is invoked (with *event* set to ``'call'``) whenever a
+new local scope is entered; it should return a reference to the local trace
+function to be used that scope, or ``None`` if the scope shouldn't be traced.
+
+The local trace function should return a reference to itself (or to another
+function for further tracing in that scope), or ``None`` to turn off tracing in
+that scope.
+
+Instance methods are accepted (and very useful!) as trace functions.
+
+The events have the following meaning:
+
+``'call'``
+   A function is called (or some other code block entered).  The global trace
+   function is called; *arg* is ``None``; the return value specifies the local
+   trace function.
+
+``'line'``
+   The interpreter is about to execute a new line of code (sometimes multiple line
+   events on one line exist).  The local trace function is called; *arg* is
+   ``None``; the return value specifies the new local trace function.
+
+``'return'``
+   A function (or other code block) is about to return.  The local trace function
+   is called; *arg* is the value that will be returned.  The trace function's
+   return value is ignored.
+
+``'exception'``
+   An exception has occurred.  The local trace function is called; *arg* is a
+   triple ``(exception, value, traceback)``; the return value specifies the new
+   local trace function.
+
+``'c_call'``
+   A C function is about to be called.  This may be an extension function or a
+   builtin.  *arg* is the C function object.
+
+``'c_return'``
+   A C function has returned. *arg* is ``None``.
+
+``'c_exception'``
+   A C function has thrown an exception.  *arg* is ``None``.
+
+Note that as an exception is propagated down the chain of callers, an
+``'exception'`` event is generated at each level.
+
+For more information on code and frame objects, refer to :ref:`types`.
+
diff --git a/Doc/library/persistence.rst b/Doc/library/persistence.rst
new file mode 100644
index 0000000..78e40f6
--- /dev/null
+++ b/Doc/library/persistence.rst
@@ -0,0 +1,32 @@
+
+.. _persistence:
+
+****************
+Data Persistence
+****************
+
+The modules described in this chapter support storing Python data in a
+persistent form on disk.  The :mod:`pickle` and :mod:`marshal` modules can turn
+many Python data types into a stream of bytes and then recreate the objects from
+the bytes.  The various DBM-related modules support a family of hash-based file
+formats that store a mapping of strings to other strings.  The :mod:`bsddb`
+module also provides such disk-based string-to-string mappings based on hashing,
+and also supports B-Tree and record-based formats.
+
+The list of modules described in this chapter is:
+
+
+.. toctree::
+
+   pickle.rst
+   copy_reg.rst
+   shelve.rst
+   marshal.rst
+   anydbm.rst
+   whichdb.rst
+   dbm.rst
+   gdbm.rst
+   dbhash.rst
+   bsddb.rst
+   dumbdbm.rst
+   sqlite3.rst
diff --git a/Doc/library/pickle.rst b/Doc/library/pickle.rst
new file mode 100644
index 0000000..ab19ff8
--- /dev/null
+++ b/Doc/library/pickle.rst
@@ -0,0 +1,868 @@
+
+:mod:`pickle` --- Python object serialization
+=============================================
+
+.. index::
+   single: persistence
+   pair: persistent; objects
+   pair: serializing; objects
+   pair: marshalling; objects
+   pair: flattening; objects
+   pair: pickling; objects
+
+.. module:: pickle
+   :synopsis: Convert Python objects to streams of bytes and back.
+
+
+.. % Substantial improvements by Jim Kerr .
+.. % Rewritten by Barry Warsaw 
+
+The :mod:`pickle` module implements a fundamental, but powerful algorithm for
+serializing and de-serializing a Python object structure.  "Pickling" is the
+process whereby a Python object hierarchy is converted into a byte stream, and
+"unpickling" is the inverse operation, whereby a byte stream is converted back
+into an object hierarchy.  Pickling (and unpickling) is alternatively known as
+"serialization", "marshalling," [#]_ or "flattening", however, to avoid
+confusion, the terms used here are "pickling" and "unpickling".
+
+This documentation describes both the :mod:`pickle` module and the
+:mod:`cPickle` module.
+
+
+Relationship to other Python modules
+------------------------------------
+
+The :mod:`pickle` module has an optimized cousin called the :mod:`cPickle`
+module.  As its name implies, :mod:`cPickle` is written in C, so it can be up to
+1000 times faster than :mod:`pickle`.  However it does not support subclassing
+of the :func:`Pickler` and :func:`Unpickler` classes, because in :mod:`cPickle`
+these are functions, not classes.  Most applications have no need for this
+functionality, and can benefit from the improved performance of :mod:`cPickle`.
+Other than that, the interfaces of the two modules are nearly identical; the
+common interface is described in this manual and differences are pointed out
+where necessary.  In the following discussions, we use the term "pickle" to
+collectively describe the :mod:`pickle` and :mod:`cPickle` modules.
+
+The data streams the two modules produce are guaranteed to be interchangeable.
+
+Python has a more primitive serialization module called :mod:`marshal`, but in
+general :mod:`pickle` should always be the preferred way to serialize Python
+objects.  :mod:`marshal` exists primarily to support Python's :file:`.pyc`
+files.
+
+The :mod:`pickle` module differs from :mod:`marshal` several significant ways:
+
+* The :mod:`pickle` module keeps track of the objects it has already serialized,
+  so that later references to the same object won't be serialized again.
+  :mod:`marshal` doesn't do this.
+
+  This has implications both for recursive objects and object sharing.  Recursive
+  objects are objects that contain references to themselves.  These are not
+  handled by marshal, and in fact, attempting to marshal recursive objects will
+  crash your Python interpreter.  Object sharing happens when there are multiple
+  references to the same object in different places in the object hierarchy being
+  serialized.  :mod:`pickle` stores such objects only once, and ensures that all
+  other references point to the master copy.  Shared objects remain shared, which
+  can be very important for mutable objects.
+
+* :mod:`marshal` cannot be used to serialize user-defined classes and their
+  instances.  :mod:`pickle` can save and restore class instances transparently,
+  however the class definition must be importable and live in the same module as
+  when the object was stored.
+
+* The :mod:`marshal` serialization format is not guaranteed to be portable
+  across Python versions.  Because its primary job in life is to support
+  :file:`.pyc` files, the Python implementers reserve the right to change the
+  serialization format in non-backwards compatible ways should the need arise.
+  The :mod:`pickle` serialization format is guaranteed to be backwards compatible
+  across Python releases.
+
+.. warning::
+
+   The :mod:`pickle` module is not intended to be secure against erroneous or
+   maliciously constructed data.  Never unpickle data received from an untrusted or
+   unauthenticated source.
+
+Note that serialization is a more primitive notion than persistence; although
+:mod:`pickle` reads and writes file objects, it does not handle the issue of
+naming persistent objects, nor the (even more complicated) issue of concurrent
+access to persistent objects.  The :mod:`pickle` module can transform a complex
+object into a byte stream and it can transform the byte stream into an object
+with the same internal structure.  Perhaps the most obvious thing to do with
+these byte streams is to write them onto a file, but it is also conceivable to
+send them across a network or store them in a database.  The module
+:mod:`shelve` provides a simple interface to pickle and unpickle objects on
+DBM-style database files.
+
+
+Data stream format
+------------------
+
+.. index::
+   single: XDR
+   single: External Data Representation
+
+The data format used by :mod:`pickle` is Python-specific.  This has the
+advantage that there are no restrictions imposed by external standards such as
+XDR (which can't represent pointer sharing); however it means that non-Python
+programs may not be able to reconstruct pickled Python objects.
+
+By default, the :mod:`pickle` data format uses a printable ASCII representation.
+This is slightly more voluminous than a binary representation.  The big
+advantage of using printable ASCII (and of some other characteristics of
+:mod:`pickle`'s representation) is that for debugging or recovery purposes it is
+possible for a human to read the pickled file with a standard text editor.
+
+There are currently 3 different protocols which can be used for pickling.
+
+* Protocol version 0 is the original ASCII protocol and is backwards compatible
+  with earlier versions of Python.
+
+* Protocol version 1 is the old binary format which is also compatible with
+  earlier versions of Python.
+
+* Protocol version 2 was introduced in Python 2.3.  It provides much more
+  efficient pickling of new-style classes.
+
+Refer to :pep:`307` for more information.
+
+If a *protocol* is not specified, protocol 0 is used. If *protocol* is specified
+as a negative value or :const:`HIGHEST_PROTOCOL`, the highest protocol version
+available will be used.
+
+.. versionchanged:: 2.3
+   Introduced the *protocol* parameter.
+
+A binary format, which is slightly more efficient, can be chosen by specifying a
+*protocol* version >= 1.
+
+
+Usage
+-----
+
+To serialize an object hierarchy, you first create a pickler, then you call the
+pickler's :meth:`dump` method.  To de-serialize a data stream, you first create
+an unpickler, then you call the unpickler's :meth:`load` method.  The
+:mod:`pickle` module provides the following constant:
+
+
+.. data:: HIGHEST_PROTOCOL
+
+   The highest protocol version available.  This value can be passed as a
+   *protocol* value.
+
+   .. versionadded:: 2.3
+
+.. note::
+
+   Be sure to always open pickle files created with protocols >= 1 in binary mode.
+   For the old ASCII-based pickle protocol 0 you can use either text mode or binary
+   mode as long as you stay consistent.
+
+   A pickle file written with protocol 0 in binary mode will contain lone linefeeds
+   as line terminators and therefore will look "funny" when viewed in Notepad or
+   other editors which do not support this format.
+
+The :mod:`pickle` module provides the following functions to make the pickling
+process more convenient:
+
+
+.. function:: dump(obj, file[, protocol])
+
+   Write a pickled representation of *obj* to the open file object *file*.  This is
+   equivalent to ``Pickler(file, protocol).dump(obj)``.
+
+   If the *protocol* parameter is omitted, protocol 0 is used. If *protocol* is
+   specified as a negative value or :const:`HIGHEST_PROTOCOL`, the highest protocol
+   version will be used.
+
+   .. versionchanged:: 2.3
+      Introduced the *protocol* parameter.
+
+   *file* must have a :meth:`write` method that accepts a single string argument.
+   It can thus be a file object opened for writing, a :mod:`StringIO` object, or
+   any other custom object that meets this interface.
+
+
+.. function:: load(file)
+
+   Read a string from the open file object *file* and interpret it as a pickle data
+   stream, reconstructing and returning the original object hierarchy.  This is
+   equivalent to ``Unpickler(file).load()``.
+
+   *file* must have two methods, a :meth:`read` method that takes an integer
+   argument, and a :meth:`readline` method that requires no arguments.  Both
+   methods should return a string.  Thus *file* can be a file object opened for
+   reading, a :mod:`StringIO` object, or any other custom object that meets this
+   interface.
+
+   This function automatically determines whether the data stream was written in
+   binary mode or not.
+
+
+.. function:: dumps(obj[, protocol])
+
+   Return the pickled representation of the object as a string, instead of writing
+   it to a file.
+
+   If the *protocol* parameter is omitted, protocol 0 is used. If *protocol* is
+   specified as a negative value or :const:`HIGHEST_PROTOCOL`, the highest protocol
+   version will be used.
+
+   .. versionchanged:: 2.3
+      The *protocol* parameter was added.
+
+
+.. function:: loads(string)
+
+   Read a pickled object hierarchy from a string.  Characters in the string past
+   the pickled object's representation are ignored.
+
+The :mod:`pickle` module also defines three exceptions:
+
+
+.. exception:: PickleError
+
+   A common base class for the other exceptions defined below.  This inherits from
+   :exc:`Exception`.
+
+
+.. exception:: PicklingError
+
+   This exception is raised when an unpicklable object is passed to the
+   :meth:`dump` method.
+
+
+.. exception:: UnpicklingError
+
+   This exception is raised when there is a problem unpickling an object. Note that
+   other exceptions may also be raised during unpickling, including (but not
+   necessarily limited to) :exc:`AttributeError`, :exc:`EOFError`,
+   :exc:`ImportError`, and :exc:`IndexError`.
+
+The :mod:`pickle` module also exports two callables [#]_, :class:`Pickler` and
+:class:`Unpickler`:
+
+
+.. class:: Pickler(file[, protocol])
+
+   This takes a file-like object to which it will write a pickle data stream.
+
+   If the *protocol* parameter is omitted, protocol 0 is used. If *protocol* is
+   specified as a negative value or :const:`HIGHEST_PROTOCOL`, the highest
+   protocol version will be used.
+
+   .. versionchanged:: 2.3
+      Introduced the *protocol* parameter.
+
+   *file* must have a :meth:`write` method that accepts a single string argument.
+   It can thus be an open file object, a :mod:`StringIO` object, or any other
+   custom object that meets this interface.
+
+:class:`Pickler` objects define one (or two) public methods:
+
+
+.. method:: Pickler.dump(obj)
+
+   Write a pickled representation of *obj* to the open file object given in the
+   constructor.  Either the binary or ASCII format will be used, depending on the
+   value of the *protocol* argument passed to the constructor.
+
+
+.. method:: Pickler.clear_memo()
+
+   Clears the pickler's "memo".  The memo is the data structure that remembers
+   which objects the pickler has already seen, so that shared or recursive objects
+   pickled by reference and not by value.  This method is useful when re-using
+   picklers.
+
+   .. note::
+
+      Prior to Python 2.3, :meth:`clear_memo` was only available on the picklers
+      created by :mod:`cPickle`.  In the :mod:`pickle` module, picklers have an
+      instance variable called :attr:`memo` which is a Python dictionary.  So to clear
+      the memo for a :mod:`pickle` module pickler, you could do the following::
+
+         mypickler.memo.clear()
+
+      Code that does not need to support older versions of Python should simply use
+      :meth:`clear_memo`.
+
+It is possible to make multiple calls to the :meth:`dump` method of the same
+:class:`Pickler` instance.  These must then be matched to the same number of
+calls to the :meth:`load` method of the corresponding :class:`Unpickler`
+instance.  If the same object is pickled by multiple :meth:`dump` calls, the
+:meth:`load` will all yield references to the same object. [#]_
+
+:class:`Unpickler` objects are defined as:
+
+
+.. class:: Unpickler(file)
+
+   This takes a file-like object from which it will read a pickle data stream.
+   This class automatically determines whether the data stream was written in
+   binary mode or not, so it does not need a flag as in the :class:`Pickler`
+   factory.
+
+   *file* must have two methods, a :meth:`read` method that takes an integer
+   argument, and a :meth:`readline` method that requires no arguments.  Both
+   methods should return a string.  Thus *file* can be a file object opened for
+   reading, a :mod:`StringIO` object, or any other custom object that meets this
+   interface.
+
+:class:`Unpickler` objects have one (or two) public methods:
+
+
+.. method:: Unpickler.load()
+
+   Read a pickled object representation from the open file object given in the
+   constructor, and return the reconstituted object hierarchy specified therein.
+
+   This method automatically determines whether the data stream was written in
+   binary mode or not.
+
+
+.. method:: Unpickler.noload()
+
+   This is just like :meth:`load` except that it doesn't actually create any
+   objects.  This is useful primarily for finding what's called "persistent ids"
+   that may be referenced in a pickle data stream.  See section
+   :ref:`pickle-protocol` below for more details.
+
+   **Note:** the :meth:`noload` method is currently only available on
+   :class:`Unpickler` objects created with the :mod:`cPickle` module.
+   :mod:`pickle` module :class:`Unpickler`\ s do not have the :meth:`noload`
+   method.
+
+
+What can be pickled and unpickled?
+----------------------------------
+
+The following types can be pickled:
+
+* ``None``, ``True``, and ``False``
+
+* integers, long integers, floating point numbers, complex numbers
+
+* normal and Unicode strings
+
+* tuples, lists, sets, and dictionaries containing only picklable objects
+
+* functions defined at the top level of a module
+
+* built-in functions defined at the top level of a module
+
+* classes that are defined at the top level of a module
+
+* instances of such classes whose :attr:`__dict__` or :meth:`__setstate__` is
+  picklable  (see section :ref:`pickle-protocol` for details)
+
+Attempts to pickle unpicklable objects will raise the :exc:`PicklingError`
+exception; when this happens, an unspecified number of bytes may have already
+been written to the underlying file. Trying to pickle a highly recursive data
+structure may exceed the maximum recursion depth, a :exc:`RuntimeError` will be
+raised in this case. You can carefully raise this limit with
+:func:`sys.setrecursionlimit`.
+
+Note that functions (built-in and user-defined) are pickled by "fully qualified"
+name reference, not by value.  This means that only the function name is
+pickled, along with the name of module the function is defined in.  Neither the
+function's code, nor any of its function attributes are pickled.  Thus the
+defining module must be importable in the unpickling environment, and the module
+must contain the named object, otherwise an exception will be raised. [#]_
+
+Similarly, classes are pickled by named reference, so the same restrictions in
+the unpickling environment apply.  Note that none of the class's code or data is
+pickled, so in the following example the class attribute ``attr`` is not
+restored in the unpickling environment::
+
+   class Foo:
+       attr = 'a class attr'
+
+   picklestring = pickle.dumps(Foo)
+
+These restrictions are why picklable functions and classes must be defined in
+the top level of a module.
+
+Similarly, when class instances are pickled, their class's code and data are not
+pickled along with them.  Only the instance data are pickled.  This is done on
+purpose, so you can fix bugs in a class or add methods to the class and still
+load objects that were created with an earlier version of the class.  If you
+plan to have long-lived objects that will see many versions of a class, it may
+be worthwhile to put a version number in the objects so that suitable
+conversions can be made by the class's :meth:`__setstate__` method.
+
+
+.. _pickle-protocol:
+
+The pickle protocol
+-------------------
+
+This section describes the "pickling protocol" that defines the interface
+between the pickler/unpickler and the objects that are being serialized.  This
+protocol provides a standard way for you to define, customize, and control how
+your objects are serialized and de-serialized.  The description in this section
+doesn't cover specific customizations that you can employ to make the unpickling
+environment slightly safer from untrusted pickle data streams; see section
+:ref:`pickle-sub` for more details.
+
+
+.. _pickle-inst:
+
+Pickling and unpickling normal class instances
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. index::
+   single: __getinitargs__() (copy protocol)
+   single: __init__() (instance constructor)
+
+When a pickled class instance is unpickled, its :meth:`__init__` method is
+normally *not* invoked.  If it is desirable that the :meth:`__init__` method be
+called on unpickling, an old-style class can define a method
+:meth:`__getinitargs__`, which should return a *tuple* containing the arguments
+to be passed to the class constructor (:meth:`__init__` for example).  The
+:meth:`__getinitargs__` method is called at pickle time; the tuple it returns is
+incorporated in the pickle for the instance.
+
+.. index:: single: __getnewargs__() (copy protocol)
+
+New-style types can provide a :meth:`__getnewargs__` method that is used for
+protocol 2.  Implementing this method is needed if the type establishes some
+internal invariants when the instance is created, or if the memory allocation is
+affected by the values passed to the :meth:`__new__` method for the type (as it
+is for tuples and strings).  Instances of a new-style type :class:`C` are
+created using ::
+
+   obj = C.__new__(C, *args)
+
+
+where *args* is the result of calling :meth:`__getnewargs__` on the original
+object; if there is no :meth:`__getnewargs__`, an empty tuple is assumed.
+
+.. index::
+   single: __getstate__() (copy protocol)
+   single: __setstate__() (copy protocol)
+   single: __dict__ (instance attribute)
+
+Classes can further influence how their instances are pickled; if the class
+defines the method :meth:`__getstate__`, it is called and the return state is
+pickled as the contents for the instance, instead of the contents of the
+instance's dictionary.  If there is no :meth:`__getstate__` method, the
+instance's :attr:`__dict__` is pickled.
+
+Upon unpickling, if the class also defines the method :meth:`__setstate__`, it
+is called with the unpickled state. [#]_  If there is no :meth:`__setstate__`
+method, the pickled state must be a dictionary and its items are assigned to the
+new instance's dictionary.  If a class defines both :meth:`__getstate__` and
+:meth:`__setstate__`, the state object needn't be a dictionary and these methods
+can do what they want. [#]_
+
+.. warning::
+
+   For new-style classes, if :meth:`__getstate__` returns a false value, the
+   :meth:`__setstate__` method will not be called.
+
+
+Pickling and unpickling extension types
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+When the :class:`Pickler` encounters an object of a type it knows nothing about
+--- such as an extension type --- it looks in two places for a hint of how to
+pickle it.  One alternative is for the object to implement a :meth:`__reduce__`
+method.  If provided, at pickling time :meth:`__reduce__` will be called with no
+arguments, and it must return either a string or a tuple.
+
+If a string is returned, it names a global variable whose contents are pickled
+as normal.  The string returned by :meth:`__reduce__` should be the object's
+local name relative to its module; the pickle module searches the module
+namespace to determine the object's module.
+
+When a tuple is returned, it must be between two and five elements long.
+Optional elements can either be omitted, or ``None`` can be provided  as their
+value.  The semantics of each element are:
+
+* A callable object that will be called to create the initial version of the
+  object.  The next element of the tuple will provide arguments for this callable,
+  and later elements provide additional state information that will subsequently
+  be used to fully reconstruct the pickled data.
+
+  In the unpickling environment this object must be either a class, a callable
+  registered as a "safe constructor" (see below), or it must have an attribute
+  :attr:`__safe_for_unpickling__` with a true value. Otherwise, an
+  :exc:`UnpicklingError` will be raised in the unpickling environment.  Note that
+  as usual, the callable itself is pickled by name.
+
+* A tuple of arguments for the callable object.
+
+  .. versionchanged:: 2.5
+     Formerly, this argument could also be ``None``.
+
+* Optionally, the object's state, which will be passed to the object's
+  :meth:`__setstate__` method as described in section :ref:`pickle-inst`.  If the
+  object has no :meth:`__setstate__` method, then, as above, the value must be a
+  dictionary and it will be added to the object's :attr:`__dict__`.
+
+* Optionally, an iterator (and not a sequence) yielding successive list items.
+  These list items will be pickled, and appended to the object using either
+  ``obj.append(item)`` or ``obj.extend(list_of_items)``.  This is primarily used
+  for list subclasses, but may be used by other classes as long as they have
+  :meth:`append` and :meth:`extend` methods with the appropriate signature.
+  (Whether :meth:`append` or :meth:`extend` is used depends on which pickle
+  protocol version is used as well as the number of items to append, so both must
+  be supported.)
+
+* Optionally, an iterator (not a sequence) yielding successive dictionary items,
+  which should be tuples of the form ``(key, value)``.  These items will be
+  pickled and stored to the object using ``obj[key] = value``. This is primarily
+  used for dictionary subclasses, but may be used by other classes as long as they
+  implement :meth:`__setitem__`.
+
+It is sometimes useful to know the protocol version when implementing
+:meth:`__reduce__`.  This can be done by implementing a method named
+:meth:`__reduce_ex__` instead of :meth:`__reduce__`. :meth:`__reduce_ex__`, when
+it exists, is called in preference over :meth:`__reduce__` (you may still
+provide :meth:`__reduce__` for backwards compatibility).  The
+:meth:`__reduce_ex__` method will be called with a single integer argument, the
+protocol version.
+
+The :class:`object` class implements both :meth:`__reduce__` and
+:meth:`__reduce_ex__`; however, if a subclass overrides :meth:`__reduce__` but
+not :meth:`__reduce_ex__`, the :meth:`__reduce_ex__` implementation detects this
+and calls :meth:`__reduce__`.
+
+An alternative to implementing a :meth:`__reduce__` method on the object to be
+pickled, is to register the callable with the :mod:`copy_reg` module.  This
+module provides a way for programs to register "reduction functions" and
+constructors for user-defined types.   Reduction functions have the same
+semantics and interface as the :meth:`__reduce__` method described above, except
+that they are called with a single argument, the object to be pickled.
+
+The registered constructor is deemed a "safe constructor" for purposes of
+unpickling as described above.
+
+
+Pickling and unpickling external objects
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+For the benefit of object persistence, the :mod:`pickle` module supports the
+notion of a reference to an object outside the pickled data stream.  Such
+objects are referenced by a "persistent id", which is just an arbitrary string
+of printable ASCII characters. The resolution of such names is not defined by
+the :mod:`pickle` module; it will delegate this resolution to user defined
+functions on the pickler and unpickler. [#]_
+
+To define external persistent id resolution, you need to set the
+:attr:`persistent_id` attribute of the pickler object and the
+:attr:`persistent_load` attribute of the unpickler object.
+
+To pickle objects that have an external persistent id, the pickler must have a
+custom :func:`persistent_id` method that takes an object as an argument and
+returns either ``None`` or the persistent id for that object.  When ``None`` is
+returned, the pickler simply pickles the object as normal.  When a persistent id
+string is returned, the pickler will pickle that string, along with a marker so
+that the unpickler will recognize the string as a persistent id.
+
+To unpickle external objects, the unpickler must have a custom
+:func:`persistent_load` function that takes a persistent id string and returns
+the referenced object.
+
+Here's a silly example that *might* shed more light::
+
+   import pickle
+   from cStringIO import StringIO
+
+   src = StringIO()
+   p = pickle.Pickler(src)
+
+   def persistent_id(obj):
+       if hasattr(obj, 'x'):
+           return 'the value %d' % obj.x
+       else:
+           return None
+
+   p.persistent_id = persistent_id
+
+   class Integer:
+       def __init__(self, x):
+           self.x = x
+       def __str__(self):
+           return 'My name is integer %d' % self.x
+
+   i = Integer(7)
+   print i
+   p.dump(i)
+
+   datastream = src.getvalue()
+   print repr(datastream)
+   dst = StringIO(datastream)
+
+   up = pickle.Unpickler(dst)
+
+   class FancyInteger(Integer):
+       def __str__(self):
+           return 'I am the integer %d' % self.x
+
+   def persistent_load(persid):
+       if persid.startswith('the value '):
+           value = int(persid.split()[2])
+           return FancyInteger(value)
+       else:
+           raise pickle.UnpicklingError, 'Invalid persistent id'
+
+   up.persistent_load = persistent_load
+
+   j = up.load()
+   print j
+
+In the :mod:`cPickle` module, the unpickler's :attr:`persistent_load` attribute
+can also be set to a Python list, in which case, when the unpickler reaches a
+persistent id, the persistent id string will simply be appended to this list.
+This functionality exists so that a pickle data stream can be "sniffed" for
+object references without actually instantiating all the objects in a pickle.
+[#]_  Setting :attr:`persistent_load` to a list is usually used in conjunction
+with the :meth:`noload` method on the Unpickler.
+
+.. % BAW: Both pickle and cPickle support something called
+.. % inst_persistent_id() which appears to give unknown types a second
+.. % shot at producing a persistent id.  Since Jim Fulton can't remember
+.. % why it was added or what it's for, I'm leaving it undocumented.
+
+
+.. _pickle-sub:
+
+Subclassing Unpicklers
+----------------------
+
+By default, unpickling will import any class that it finds in the pickle data.
+You can control exactly what gets unpickled and what gets called by customizing
+your unpickler.  Unfortunately, exactly how you do this is different depending
+on whether you're using :mod:`pickle` or :mod:`cPickle`. [#]_
+
+In the :mod:`pickle` module, you need to derive a subclass from
+:class:`Unpickler`, overriding the :meth:`load_global` method.
+:meth:`load_global` should read two lines from the pickle data stream where the
+first line will the name of the module containing the class and the second line
+will be the name of the instance's class.  It then looks up the class, possibly
+importing the module and digging out the attribute, then it appends what it
+finds to the unpickler's stack.  Later on, this class will be assigned to the
+:attr:`__class__` attribute of an empty class, as a way of magically creating an
+instance without calling its class's :meth:`__init__`. Your job (should you
+choose to accept it), would be to have :meth:`load_global` push onto the
+unpickler's stack, a known safe version of any class you deem safe to unpickle.
+It is up to you to produce such a class.  Or you could raise an error if you
+want to disallow all unpickling of instances.  If this sounds like a hack,
+you're right.  Refer to the source code to make this work.
+
+Things are a little cleaner with :mod:`cPickle`, but not by much. To control
+what gets unpickled, you can set the unpickler's :attr:`find_global` attribute
+to a function or ``None``.  If it is ``None`` then any attempts to unpickle
+instances will raise an :exc:`UnpicklingError`.  If it is a function, then it
+should accept a module name and a class name, and return the corresponding class
+object.  It is responsible for looking up the class and performing any necessary
+imports, and it may raise an error to prevent instances of the class from being
+unpickled.
+
+The moral of the story is that you should be really careful about the source of
+the strings your application unpickles.
+
+
+.. _pickle-example:
+
+Example
+-------
+
+For the simplest code, use the :func:`dump` and :func:`load` functions.  Note
+that a self-referencing list is pickled and restored correctly. ::
+
+   import pickle
+
+   data1 = {'a': [1, 2.0, 3, 4+6j],
+            'b': ('string', u'Unicode string'),
+            'c': None}
+
+   selfref_list = [1, 2, 3]
+   selfref_list.append(selfref_list)
+
+   output = open('data.pkl', 'wb')
+
+   # Pickle dictionary using protocol 0.
+   pickle.dump(data1, output)
+
+   # Pickle the list using the highest protocol available.
+   pickle.dump(selfref_list, output, -1)
+
+   output.close()
+
+The following example reads the resulting pickled data.  When reading a
+pickle-containing file, you should open the file in binary mode because you
+can't be sure if the ASCII or binary format was used. ::
+
+   import pprint, pickle
+
+   pkl_file = open('data.pkl', 'rb')
+
+   data1 = pickle.load(pkl_file)
+   pprint.pprint(data1)
+
+   data2 = pickle.load(pkl_file)
+   pprint.pprint(data2)
+
+   pkl_file.close()
+
+Here's a larger example that shows how to modify pickling behavior for a class.
+The :class:`TextReader` class opens a text file, and returns the line number and
+line contents each time its :meth:`readline` method is called. If a
+:class:`TextReader` instance is pickled, all attributes *except* the file object
+member are saved. When the instance is unpickled, the file is reopened, and
+reading resumes from the last location. The :meth:`__setstate__` and
+:meth:`__getstate__` methods are used to implement this behavior. ::
+
+   #!/usr/local/bin/python
+
+   class TextReader:
+       """Print and number lines in a text file."""
+       def __init__(self, file):
+           self.file = file
+           self.fh = open(file)
+           self.lineno = 0
+
+       def readline(self):
+           self.lineno = self.lineno + 1
+           line = self.fh.readline()
+           if not line:
+               return None
+           if line.endswith("\n"):
+               line = line[:-1]
+           return "%d: %s" % (self.lineno, line)
+
+       def __getstate__(self):
+           odict = self.__dict__.copy() # copy the dict since we change it
+           del odict['fh']              # remove filehandle entry
+           return odict
+
+       def __setstate__(self, dict):
+           fh = open(dict['file'])      # reopen file
+           count = dict['lineno']       # read from file...
+           while count:                 # until line count is restored
+               fh.readline()
+               count = count - 1
+           self.__dict__.update(dict)   # update attributes
+           self.fh = fh                 # save the file object
+
+A sample usage might be something like this::
+
+   >>> import TextReader
+   >>> obj = TextReader.TextReader("TextReader.py")
+   >>> obj.readline()
+   '1: #!/usr/local/bin/python'
+   >>> obj.readline()
+   '2: '
+   >>> obj.readline()
+   '3: class TextReader:'
+   >>> import pickle
+   >>> pickle.dump(obj, open('save.p', 'wb'))
+
+If you want to see that :mod:`pickle` works across Python processes, start
+another Python session, before continuing.  What follows can happen from either
+the same process or a new process. ::
+
+   >>> import pickle
+   >>> reader = pickle.load(open('save.p', 'rb'))
+   >>> reader.readline()
+   '4:     """Print and number lines in a text file."""'
+
+
+.. seealso::
+
+   Module :mod:`copy_reg`
+      Pickle interface constructor registration for extension types.
+
+   Module :mod:`shelve`
+      Indexed databases of objects; uses :mod:`pickle`.
+
+   Module :mod:`copy`
+      Shallow and deep object copying.
+
+   Module :mod:`marshal`
+      High-performance serialization of built-in types.
+
+
+:mod:`cPickle` --- A faster :mod:`pickle`
+=========================================
+
+.. module:: cPickle
+   :synopsis: Faster version of pickle, but not subclassable.
+.. moduleauthor:: Jim Fulton 
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+.. index:: module: pickle
+
+The :mod:`cPickle` module supports serialization and de-serialization of Python
+objects, providing an interface and functionality nearly identical to the
+:mod:`pickle` module.  There are several differences, the most important being
+performance and subclassability.
+
+First, :mod:`cPickle` can be up to 1000 times faster than :mod:`pickle` because
+the former is implemented in C.  Second, in the :mod:`cPickle` module the
+callables :func:`Pickler` and :func:`Unpickler` are functions, not classes.
+This means that you cannot use them to derive custom pickling and unpickling
+subclasses.  Most applications have no need for this functionality and should
+benefit from the greatly improved performance of the :mod:`cPickle` module.
+
+The pickle data stream produced by :mod:`pickle` and :mod:`cPickle` are
+identical, so it is possible to use :mod:`pickle` and :mod:`cPickle`
+interchangeably with existing pickles. [#]_
+
+There are additional minor differences in API between :mod:`cPickle` and
+:mod:`pickle`, however for most applications, they are interchangeable.  More
+documentation is provided in the :mod:`pickle` module documentation, which
+includes a list of the documented differences.
+
+.. rubric:: Footnotes
+
+.. [#] Don't confuse this with the :mod:`marshal` module
+
+.. [#] In the :mod:`pickle` module these callables are classes, which you could
+   subclass to customize the behavior.  However, in the :mod:`cPickle` module these
+   callables are factory functions and so cannot be subclassed.  One common reason
+   to subclass is to control what objects can actually be unpickled.  See section
+   :ref:`pickle-sub` for more details.
+
+.. [#] *Warning*: this is intended for pickling multiple objects without intervening
+   modifications to the objects or their parts.  If you modify an object and then
+   pickle it again using the same :class:`Pickler` instance, the object is not
+   pickled again --- a reference to it is pickled and the :class:`Unpickler` will
+   return the old value, not the modified one. There are two problems here: (1)
+   detecting changes, and (2) marshalling a minimal set of changes.  Garbage
+   Collection may also become a problem here.
+
+.. [#] The exception raised will likely be an :exc:`ImportError` or an
+   :exc:`AttributeError` but it could be something else.
+
+.. [#] These methods can also be used to implement copying class instances.
+
+.. [#] This protocol is also used by the shallow and deep copying operations defined in
+   the :mod:`copy` module.
+
+.. [#] The actual mechanism for associating these user defined functions is slightly
+   different for :mod:`pickle` and :mod:`cPickle`.  The description given here
+   works the same for both implementations.  Users of the :mod:`pickle` module
+   could also use subclassing to effect the same results, overriding the
+   :meth:`persistent_id` and :meth:`persistent_load` methods in the derived
+   classes.
+
+.. [#] We'll leave you with the image of Guido and Jim sitting around sniffing pickles
+   in their living rooms.
+
+.. [#] A word of caution: the mechanisms described here use internal attributes and
+   methods, which are subject to change in future versions of Python.  We intend to
+   someday provide a common interface for controlling this behavior, which will
+   work in either :mod:`pickle` or :mod:`cPickle`.
+
+.. [#] Since the pickle data format is actually a tiny stack-oriented programming
+   language, and some freedom is taken in the encodings of certain objects, it is
+   possible that the two modules produce different data streams for the same input
+   objects.  However it is guaranteed that they will always be able to read each
+   other's data streams.
+
diff --git a/Doc/library/pickletools.rst b/Doc/library/pickletools.rst
new file mode 100644
index 0000000..ec220d9
--- /dev/null
+++ b/Doc/library/pickletools.rst
@@ -0,0 +1,37 @@
+
+:mod:`pickletools` --- Tools for pickle developers.
+===================================================
+
+.. module:: pickletools
+   :synopsis: Contains extensive comments about the pickle protocols and pickle-machine
+              opcodes, as well as some useful functions.
+
+
+.. versionadded:: 2.3
+
+This module contains various constants relating to the intimate details of the
+:mod:`pickle` module, some lengthy comments about the implementation, and a few
+useful functions for analyzing pickled data.  The contents of this module are
+useful for Python core developers who are working on the :mod:`pickle` and
+:mod:`cPickle` implementations; ordinary users of the :mod:`pickle` module
+probably won't find the :mod:`pickletools` module relevant.
+
+
+.. function:: dis(pickle[, out=None, memo=None, indentlevel=4])
+
+   Outputs a symbolic disassembly of the pickle to the file-like object *out*,
+   defaulting to ``sys.stdout``.  *pickle* can be a string or a file-like object.
+   *memo* can be a Python dictionary that will be used as the pickle's memo; it can
+   be used to perform disassemblies across multiple pickles created by the same
+   pickler. Successive levels, indicated by ``MARK`` opcodes in the stream, are
+   indented by *indentlevel* spaces.
+
+
+.. function:: genops(pickle)
+
+   Provides an iterator over all of the opcodes in a pickle, returning a sequence
+   of ``(opcode, arg, pos)`` triples. *opcode* is an instance of an
+   :class:`OpcodeInfo` class; *arg*  is the decoded value, as a Python object, of
+   the opcode's argument;  *pos* is the position at which this opcode is located.
+   *pickle* can be a string or a file-like object.
+
diff --git a/Doc/library/pipes.rst b/Doc/library/pipes.rst
new file mode 100644
index 0000000..1f2b2ff
--- /dev/null
+++ b/Doc/library/pipes.rst
@@ -0,0 +1,92 @@
+
+:mod:`pipes` --- Interface to shell pipelines
+=============================================
+
+.. module:: pipes
+   :platform: Unix
+   :synopsis: A Python interface to Unix shell pipelines.
+.. sectionauthor:: Moshe Zadka 
+
+
+The :mod:`pipes` module defines a class to abstract the concept of a *pipeline*
+--- a sequence of converters from one file to  another.
+
+Because the module uses :program:`/bin/sh` command lines, a POSIX or compatible
+shell for :func:`os.system` and :func:`os.popen` is required.
+
+The :mod:`pipes` module defines the following class:
+
+
+.. class:: Template()
+
+   An abstraction of a pipeline.
+
+Example::
+
+   >>> import pipes
+   >>> t=pipes.Template()
+   >>> t.append('tr a-z A-Z', '--')
+   >>> f=t.open('/tmp/1', 'w')
+   >>> f.write('hello world')
+   >>> f.close()
+   >>> open('/tmp/1').read()
+   'HELLO WORLD'
+
+
+.. _template-objects:
+
+Template Objects
+----------------
+
+Template objects following methods:
+
+
+.. method:: Template.reset()
+
+   Restore a pipeline template to its initial state.
+
+
+.. method:: Template.clone()
+
+   Return a new, equivalent, pipeline template.
+
+
+.. method:: Template.debug(flag)
+
+   If *flag* is true, turn debugging on. Otherwise, turn debugging off. When
+   debugging is on, commands to be executed are printed, and the shell is given
+   ``set -x`` command to be more verbose.
+
+
+.. method:: Template.append(cmd, kind)
+
+   Append a new action at the end. The *cmd* variable must be a valid bourne shell
+   command. The *kind* variable consists of two letters.
+
+   The first letter can be either of ``'-'`` (which means the command reads its
+   standard input), ``'f'`` (which means the commands reads a given file on the
+   command line) or ``'.'`` (which means the commands reads no input, and hence
+   must be first.)
+
+   Similarly, the second letter can be either of ``'-'`` (which means  the command
+   writes to standard output), ``'f'`` (which means the  command writes a file on
+   the command line) or ``'.'`` (which means the command does not write anything,
+   and hence must be last.)
+
+
+.. method:: Template.prepend(cmd, kind)
+
+   Add a new action at the beginning. See :meth:`append` for explanations of the
+   arguments.
+
+
+.. method:: Template.open(file, mode)
+
+   Return a file-like object, open to *file*, but read from or written to by the
+   pipeline.  Note that only one of ``'r'``, ``'w'`` may be given.
+
+
+.. method:: Template.copy(infile, outfile)
+
+   Copy *infile* to *outfile* through the pipe.
+
diff --git a/Doc/library/pkgutil.rst b/Doc/library/pkgutil.rst
new file mode 100644
index 0000000..1fbfb04
--- /dev/null
+++ b/Doc/library/pkgutil.rst
@@ -0,0 +1,43 @@
+
+:mod:`pkgutil` --- Package extension utility
+============================================
+
+.. module:: pkgutil
+   :synopsis: Utilities to support extension of packages.
+
+
+.. versionadded:: 2.3
+
+This module provides a single function:
+
+
+.. function:: extend_path(path, name)
+
+   Extend the search path for the modules which comprise a package. Intended use is
+   to place the following code in a package's :file:`__init__.py`::
+
+      from pkgutil import extend_path
+      __path__ = extend_path(__path__, __name__)
+
+   This will add to the package's ``__path__`` all subdirectories of directories on
+   ``sys.path`` named after the package.  This is useful if one wants to distribute
+   different parts of a single logical package as multiple directories.
+
+   It also looks for :file:`\*.pkg` files beginning where ``*`` matches the *name*
+   argument.  This feature is similar to :file:`\*.pth` files (see the :mod:`site`
+   module for more information), except that it doesn't special-case lines starting
+   with ``import``.  A :file:`\*.pkg` file is trusted at face value: apart from
+   checking for duplicates, all entries found in a :file:`\*.pkg` file are added to
+   the path, regardless of whether they exist on the filesystem.  (This is a
+   feature.)
+
+   If the input path is not a list (as is the case for frozen packages) it is
+   returned unchanged.  The input path is not modified; an extended copy is
+   returned.  Items are only appended to the copy at the end.
+
+   It is assumed that ``sys.path`` is a sequence.  Items of ``sys.path`` that are
+   not (Unicode or 8-bit) strings referring to existing directories are ignored.
+   Unicode items on ``sys.path`` that cause errors when used as filenames may cause
+   this function to raise an exception (in line with :func:`os.path.isdir`
+   behavior).
+
diff --git a/Doc/library/platform.rst b/Doc/library/platform.rst
new file mode 100644
index 0000000..a4570d2
--- /dev/null
+++ b/Doc/library/platform.rst
@@ -0,0 +1,256 @@
+
+:mod:`platform` ---  Access to underlying platform's identifying data.
+======================================================================
+
+.. module:: platform
+   :synopsis: Retrieves as much platform identifying data as possible.
+.. moduleauthor:: Marc-Andre Lemburg 
+.. sectionauthor:: Bjorn Pettersen 
+
+
+.. versionadded:: 2.3
+
+.. note::
+
+   Specific platforms listed alphabetically, with Linux included in the Unix
+   section.
+
+
+Cross Platform
+--------------
+
+
+.. function:: architecture(executable=sys.executable, bits='', linkage='')
+
+   Queries the given executable (defaults to the Python interpreter binary) for
+   various architecture information.
+
+   Returns a tuple ``(bits, linkage)`` which contain information about the bit
+   architecture and the linkage format used for the executable. Both values are
+   returned as strings.
+
+   Values that cannot be determined are returned as given by the parameter presets.
+   If bits is given as ``''``, the :cfunc:`sizeof(pointer)` (or
+   :cfunc:`sizeof(long)` on Python version < 1.5.2) is used as indicator for the
+   supported pointer size.
+
+   The function relies on the system's :file:`file` command to do the actual work.
+   This is available on most if not all Unix  platforms and some non-Unix platforms
+   and then only if the executable points to the Python interpreter.  Reasonable
+   defaults are used when the above needs are not met.
+
+
+.. function:: machine()
+
+   Returns the machine type, e.g. ``'i386'``. An empty string is returned if the
+   value cannot be determined.
+
+
+.. function:: node()
+
+   Returns the computer's network name (may not be fully qualified!). An empty
+   string is returned if the value cannot be determined.
+
+
+.. function:: platform(aliased=0, terse=0)
+
+   Returns a single string identifying the underlying platform with as much useful
+   information as possible.
+
+   The output is intended to be *human readable* rather than machine parseable. It
+   may look different on different platforms and this is intended.
+
+   If *aliased* is true, the function will use aliases for various platforms that
+   report system names which differ from their common names, for example SunOS will
+   be reported as Solaris.  The :func:`system_alias` function is used to implement
+   this.
+
+   Setting *terse* to true causes the function to return only the absolute minimum
+   information needed to identify the platform.
+
+
+.. function:: processor()
+
+   Returns the (real) processor name, e.g. ``'amdk6'``.
+
+   An empty string is returned if the value cannot be determined. Note that many
+   platforms do not provide this information or simply return the same value as for
+   :func:`machine`.  NetBSD does this.
+
+
+.. function:: python_build()
+
+   Returns a tuple ``(buildno, builddate)`` stating the Python build number and
+   date as strings.
+
+
+.. function:: python_compiler()
+
+   Returns a string identifying the compiler used for compiling Python.
+
+
+.. function:: python_branch()
+
+   Returns a string identifying the Python implementation SCM branch.
+
+   .. versionadded:: 2.6
+
+
+.. function:: python_implementation()
+
+   Returns a string identifying the Python implementation. Possible return values
+   are: 'CPython', 'IronPython', 'Jython'
+
+   .. versionadded:: 2.6
+
+
+.. function:: python_revision()
+
+   Returns a string identifying the Python implementation SCM revision.
+
+   .. versionadded:: 2.6
+
+
+.. function:: python_version()
+
+   Returns the Python version as string ``'major.minor.patchlevel'``
+
+   Note that unlike the Python ``sys.version``, the returned value will always
+   include the patchlevel (it defaults to 0).
+
+
+.. function:: python_version_tuple()
+
+   Returns the Python version as tuple ``(major, minor, patchlevel)`` of strings.
+
+   Note that unlike the Python ``sys.version``, the returned value will always
+   include the patchlevel (it defaults to ``'0'``).
+
+
+.. function:: release()
+
+   Returns the system's release, e.g. ``'2.2.0'`` or ``'NT'`` An empty string is
+   returned if the value cannot be determined.
+
+
+.. function:: system()
+
+   Returns the system/OS name, e.g. ``'Linux'``, ``'Windows'``, or ``'Java'``. An
+   empty string is returned if the value cannot be determined.
+
+
+.. function:: system_alias(system, release, version)
+
+   Returns ``(system, release, version)`` aliased to common marketing names used
+   for some systems.  It also does some reordering of the information in some cases
+   where it would otherwise cause confusion.
+
+
+.. function:: version()
+
+   Returns the system's release version, e.g. ``'#3 on degas'``. An empty string is
+   returned if the value cannot be determined.
+
+
+.. function:: uname()
+
+   Fairly portable uname interface. Returns a tuple of strings ``(system, node,
+   release, version, machine, processor)`` identifying the underlying platform.
+
+   Note that unlike the :func:`os.uname` function this also returns possible
+   processor information as additional tuple entry.
+
+   Entries which cannot be determined are set to ``''``.
+
+
+Java Platform
+-------------
+
+
+.. function:: java_ver(release='', vendor='', vminfo=('','',''), osinfo=('','',''))
+
+   Version interface for JPython.
+
+   Returns a tuple ``(release, vendor, vminfo, osinfo)`` with *vminfo* being a
+   tuple ``(vm_name, vm_release, vm_vendor)`` and *osinfo* being a tuple
+   ``(os_name, os_version, os_arch)``. Values which cannot be determined are set to
+   the defaults given as parameters (which all default to ``''``).
+
+
+Windows Platform
+----------------
+
+
+.. function:: win32_ver(release='', version='', csd='', ptype='')
+
+   Get additional version information from the Windows Registry and return a tuple
+   ``(version, csd, ptype)`` referring to version number, CSD level and OS type
+   (multi/single processor).
+
+   As a hint: *ptype* is ``'Uniprocessor Free'`` on single processor NT machines
+   and ``'Multiprocessor Free'`` on multi processor machines. The *'Free'* refers
+   to the OS version being free of debugging code. It could also state *'Checked'*
+   which means the OS version uses debugging code, i.e. code that checks arguments,
+   ranges, etc.
+
+   .. note::
+
+      This function only works if Mark Hammond's :mod:`win32all` package is installed
+      and (obviously) only runs on Win32 compatible platforms.
+
+
+Win95/98 specific
+^^^^^^^^^^^^^^^^^
+
+
+.. function:: popen(cmd, mode='r', bufsize=None)
+
+   Portable :func:`popen` interface.  Find a working popen implementation
+   preferring :func:`win32pipe.popen`.  On Windows NT, :func:`win32pipe.popen`
+   should work; on Windows 9x it hangs due to bugs in the MS C library.
+
+   .. % This KnowledgeBase article appears to be missing...
+   .. % See also \ulink{MS KnowledgeBase article Q150956}{}.
+
+
+Mac OS Platform
+---------------
+
+
+.. function:: mac_ver(release='', versioninfo=('','',''), machine='')
+
+   Get Mac OS version information and return it as tuple ``(release, versioninfo,
+   machine)`` with *versioninfo* being a tuple ``(version, dev_stage,
+   non_release_version)``.
+
+   Entries which cannot be determined are set to ``''``.  All tuple entries are
+   strings.
+
+   Documentation for the underlying :cfunc:`gestalt` API is available online at
+   http://www.rgaros.nl/gestalt/.
+
+
+Unix Platforms
+--------------
+
+
+.. function:: dist(distname='', version='', id='', supported_dists=('SuSE','debian','redhat','mandrake'))
+
+   Tries to determine the name of the OS distribution name Returns a tuple
+   ``(distname, version, id)`` which defaults to the args given as parameters.
+
+.. % Document linux_distribution()?
+
+
+.. function:: libc_ver(executable=sys.executable, lib='', version='', chunksize=2048)
+
+   Tries to determine the libc version against which the file executable (defaults
+   to the Python interpreter) is linked.  Returns a tuple of strings ``(lib,
+   version)`` which default to the given parameters in case the lookup fails.
+
+   Note that this function has intimate knowledge of how different libc versions
+   add symbols to the executable is probably only useable for executables compiled
+   using :program:`gcc`.
+
+   The file is read and scanned in chunks of *chunksize* bytes.
+
diff --git a/Doc/library/poplib.rst b/Doc/library/poplib.rst
new file mode 100644
index 0000000..5716204
--- /dev/null
+++ b/Doc/library/poplib.rst
@@ -0,0 +1,202 @@
+
+:mod:`poplib` --- POP3 protocol client
+======================================
+
+.. module:: poplib
+   :synopsis: POP3 protocol client (requires sockets).
+
+
+.. index:: pair: POP3; protocol
+
+.. % By Andrew T. Csillag
+.. % Even though I put it into LaTeX, I cannot really claim that I wrote
+.. % it since I just stole most of it from the poplib.py source code and
+.. % the imaplib ``chapter''.
+.. % Revised by ESR, January 2000
+
+This module defines a class, :class:`POP3`, which encapsulates a connection to a
+POP3 server and implements the protocol as defined in :rfc:`1725`.  The
+:class:`POP3` class supports both the minimal and optional command sets.
+Additionally, this module provides a class :class:`POP3_SSL`, which provides
+support for connecting to POP3 servers that use SSL as an underlying protocol
+layer.
+
+Note that POP3, though widely supported, is obsolescent.  The implementation
+quality of POP3 servers varies widely, and too many are quite poor. If your
+mailserver supports IMAP, you would be better off using the
+:class:`imaplib.IMAP4` class, as IMAP servers tend to be better implemented.
+
+A single class is provided by the :mod:`poplib` module:
+
+
+.. class:: POP3(host[, port[, timeout]])
+
+   This class implements the actual POP3 protocol.  The connection is created when
+   the instance is initialized. If *port* is omitted, the standard POP3 port (110)
+   is used. The optional *timeout* parameter specifies a timeout in seconds for the
+   connection attempt (if not specified, or passed as None, the global default
+   timeout setting will be used).
+
+   .. versionchanged:: 2.6
+      *timeout* was added.
+
+
+.. class:: POP3_SSL(host[, port[, keyfile[, certfile]]])
+
+   This is a subclass of :class:`POP3` that connects to the server over an SSL
+   encrypted socket.  If *port* is not specified, 995, the standard POP3-over-SSL
+   port is used.  *keyfile* and *certfile* are also optional - they can contain a
+   PEM formatted private key and certificate chain file for the SSL connection.
+
+   .. versionadded:: 2.4
+
+One exception is defined as an attribute of the :mod:`poplib` module:
+
+
+.. exception:: error_proto
+
+   Exception raised on any errors from this module (errors from :mod:`socket`
+   module are not caught). The reason for the exception is passed to the
+   constructor as a string.
+
+
+.. seealso::
+
+   Module :mod:`imaplib`
+      The standard Python IMAP module.
+
+   `Frequently Asked Questions About Fetchmail `_
+      The FAQ for the :program:`fetchmail` POP/IMAP client collects information on
+      POP3 server variations and RFC noncompliance that may be useful if you need to
+      write an application based on the POP protocol.
+
+
+.. _pop3-objects:
+
+POP3 Objects
+------------
+
+All POP3 commands are represented by methods of the same name, in lower-case;
+most return the response text sent by the server.
+
+An :class:`POP3` instance has the following methods:
+
+
+.. method:: POP3.set_debuglevel(level)
+
+   Set the instance's debugging level.  This controls the amount of debugging
+   output printed.  The default, ``0``, produces no debugging output.  A value of
+   ``1`` produces a moderate amount of debugging output, generally a single line
+   per request.  A value of ``2`` or higher produces the maximum amount of
+   debugging output, logging each line sent and received on the control connection.
+
+
+.. method:: POP3.getwelcome()
+
+   Returns the greeting string sent by the POP3 server.
+
+
+.. method:: POP3.user(username)
+
+   Send user command, response should indicate that a password is required.
+
+
+.. method:: POP3.pass_(password)
+
+   Send password, response includes message count and mailbox size. Note: the
+   mailbox on the server is locked until :meth:`quit` is called.
+
+
+.. method:: POP3.apop(user, secret)
+
+   Use the more secure APOP authentication to log into the POP3 server.
+
+
+.. method:: POP3.rpop(user)
+
+   Use RPOP authentication (similar to UNIX r-commands) to log into POP3 server.
+
+
+.. method:: POP3.stat()
+
+   Get mailbox status.  The result is a tuple of 2 integers: ``(message count,
+   mailbox size)``.
+
+
+.. method:: POP3.list([which])
+
+   Request message list, result is in the form ``(response, ['mesg_num octets',
+   ...], octets)``. If *which* is set, it is the message to list.
+
+
+.. method:: POP3.retr(which)
+
+   Retrieve whole message number *which*, and set its seen flag. Result is in form
+   ``(response, ['line', ...], octets)``.
+
+
+.. method:: POP3.dele(which)
+
+   Flag message number *which* for deletion.  On most servers deletions are not
+   actually performed until QUIT (the major exception is Eudora QPOP, which
+   deliberately violates the RFCs by doing pending deletes on any disconnect).
+
+
+.. method:: POP3.rset()
+
+   Remove any deletion marks for the mailbox.
+
+
+.. method:: POP3.noop()
+
+   Do nothing.  Might be used as a keep-alive.
+
+
+.. method:: POP3.quit()
+
+   Signoff:  commit changes, unlock mailbox, drop connection.
+
+
+.. method:: POP3.top(which, howmuch)
+
+   Retrieves the message header plus *howmuch* lines of the message after the
+   header of message number *which*. Result is in form ``(response, ['line', ...],
+   octets)``.
+
+   The POP3 TOP command this method uses, unlike the RETR command, doesn't set the
+   message's seen flag; unfortunately, TOP is poorly specified in the RFCs and is
+   frequently broken in off-brand servers. Test this method by hand against the
+   POP3 servers you will use before trusting it.
+
+
+.. method:: POP3.uidl([which])
+
+   Return message digest (unique id) list. If *which* is specified, result contains
+   the unique id for that message in the form ``'response mesgnum uid``, otherwise
+   result is list ``(response, ['mesgnum uid', ...], octets)``.
+
+Instances of :class:`POP3_SSL` have no additional methods. The interface of this
+subclass is identical to its parent.
+
+
+.. _pop3-example:
+
+POP3 Example
+------------
+
+Here is a minimal example (without error checking) that opens a mailbox and
+retrieves and prints all messages::
+
+   import getpass, poplib
+
+   M = poplib.POP3('localhost')
+   M.user(getpass.getuser())
+   M.pass_(getpass.getpass())
+   numMessages = len(M.list()[1])
+   for i in range(numMessages):
+       for j in M.retr(i+1)[1]:
+           print j
+
+At the end of the module, there is a test section that contains a more extensive
+example of usage.
+
diff --git a/Doc/library/posix.rst b/Doc/library/posix.rst
new file mode 100644
index 0000000..07ecb48
--- /dev/null
+++ b/Doc/library/posix.rst
@@ -0,0 +1,103 @@
+
+:mod:`posix` --- The most common POSIX system calls
+===================================================
+
+.. module:: posix
+   :platform: Unix
+   :synopsis: The most common POSIX system calls (normally used via module os).
+
+
+This module provides access to operating system functionality that is
+standardized by the C Standard and the POSIX standard (a thinly disguised Unix
+interface).
+
+.. index:: module: os
+
+**Do not import this module directly.**  Instead, import the module :mod:`os`,
+which provides a *portable* version of this interface.  On Unix, the :mod:`os`
+module provides a superset of the :mod:`posix` interface.  On non-Unix operating
+systems the :mod:`posix` module is not available, but a subset is always
+available through the :mod:`os` interface.  Once :mod:`os` is imported, there is
+*no* performance penalty in using it instead of :mod:`posix`.  In addition,
+:mod:`os` provides some additional functionality, such as automatically calling
+:func:`putenv` when an entry in ``os.environ`` is changed.
+
+The descriptions below are very terse; refer to the corresponding Unix manual
+(or POSIX documentation) entry for more information. Arguments called *path*
+refer to a pathname given as a string.
+
+Errors are reported as exceptions; the usual exceptions are given for type
+errors, while errors reported by the system calls raise :exc:`error` (a synonym
+for the standard exception :exc:`OSError`), described below.
+
+
+.. _posix-large-files:
+
+Large File Support
+------------------
+
+.. index::
+   single: large files
+   single: file; large files
+
+.. sectionauthor:: Steve Clift 
+
+
+Several operating systems (including AIX, HPUX, Irix and Solaris) provide
+support for files that are larger than 2 Gb from a C programming model where
+:ctype:`int` and :ctype:`long` are 32-bit values. This is typically accomplished
+by defining the relevant size and offset types as 64-bit values. Such files are
+sometimes referred to as :dfn:`large files`.
+
+Large file support is enabled in Python when the size of an :ctype:`off_t` is
+larger than a :ctype:`long` and the :ctype:`long long` type is available and is
+at least as large as an :ctype:`off_t`. Python longs are then used to represent
+file sizes, offsets and other values that can exceed the range of a Python int.
+It may be necessary to configure and compile Python with certain compiler flags
+to enable this mode. For example, it is enabled by default with recent versions
+of Irix, but with Solaris 2.6 and 2.7 you need to do something like::
+
+   CFLAGS="`getconf LFS_CFLAGS`" OPT="-g -O2 $CFLAGS" \
+           ./configure
+
+On large-file-capable Linux systems, this might work:
+
+.. % $ <-- bow to font-lock
+
+::
+
+   CFLAGS='-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64' OPT="-g -O2 $CFLAGS" \
+           ./configure
+
+.. % $ <-- bow to font-lock
+
+
+.. _posix-contents:
+
+Module Contents
+---------------
+
+Module :mod:`posix` defines the following data item:
+
+
+.. data:: environ
+
+   A dictionary representing the string environment at the time the interpreter was
+   started. For example, ``environ['HOME']`` is the pathname of your home
+   directory, equivalent to ``getenv("HOME")`` in C.
+
+   Modifying this dictionary does not affect the string environment passed on by
+   :func:`execv`, :func:`popen` or :func:`system`; if you need to change the
+   environment, pass ``environ`` to :func:`execve` or add variable assignments and
+   export statements to the command string for :func:`system` or :func:`popen`.
+
+   .. note::
+
+      The :mod:`os` module provides an alternate implementation of ``environ`` which
+      updates the environment on modification.  Note also that updating ``os.environ``
+      will render this dictionary obsolete.  Use of the :mod:`os` module version of
+      this is recommended over direct access to the :mod:`posix` module.
+
+Additional contents of this module should only be accessed via the :mod:`os`
+module; refer to the documentation for that module for further information.
+
diff --git a/Doc/library/pprint.rst b/Doc/library/pprint.rst
new file mode 100644
index 0000000..3630176
--- /dev/null
+++ b/Doc/library/pprint.rst
@@ -0,0 +1,213 @@
+
+:mod:`pprint` --- Data pretty printer
+=====================================
+
+.. module:: pprint
+   :synopsis: Data pretty printer.
+.. moduleauthor:: Fred L. Drake, Jr. 
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+The :mod:`pprint` module provides a capability to "pretty-print" arbitrary
+Python data structures in a form which can be used as input to the interpreter.
+If the formatted structures include objects which are not fundamental Python
+types, the representation may not be loadable.  This may be the case if objects
+such as files, sockets, classes, or instances are included, as well as many
+other builtin objects which are not representable as Python constants.
+
+The formatted representation keeps objects on a single line if it can, and
+breaks them onto multiple lines if they don't fit within the allowed width.
+Construct :class:`PrettyPrinter` objects explicitly if you need to adjust the
+width constraint.
+
+.. versionchanged:: 2.5
+   Dictionaries are sorted by key before the display is computed; before 2.5, a
+   dictionary was sorted only if its display required more than one line, although
+   that wasn't documented.
+
+The :mod:`pprint` module defines one class:
+
+.. % First the implementation class:
+
+
+.. class:: PrettyPrinter(...)
+
+   Construct a :class:`PrettyPrinter` instance.  This constructor understands
+   several keyword parameters.  An output stream may be set using the *stream*
+   keyword; the only method used on the stream object is the file protocol's
+   :meth:`write` method.  If not specified, the :class:`PrettyPrinter` adopts
+   ``sys.stdout``.  Three additional parameters may be used to control the
+   formatted representation.  The keywords are *indent*, *depth*, and *width*.  The
+   amount of indentation added for each recursive level is specified by *indent*;
+   the default is one.  Other values can cause output to look a little odd, but can
+   make nesting easier to spot.  The number of levels which may be printed is
+   controlled by *depth*; if the data structure being printed is too deep, the next
+   contained level is replaced by ``...``.  By default, there is no constraint on
+   the depth of the objects being formatted.  The desired output width is
+   constrained using the *width* parameter; the default is 80 characters.  If a
+   structure cannot be formatted within the constrained width, a best effort will
+   be made. ::
+
+      >>> import pprint, sys
+      >>> stuff = sys.path[:]
+      >>> stuff.insert(0, stuff[:])
+      >>> pp = pprint.PrettyPrinter(indent=4)
+      >>> pp.pprint(stuff)
+      [   [   '',
+              '/usr/local/lib/python1.5',
+              '/usr/local/lib/python1.5/test',
+              '/usr/local/lib/python1.5/sunos5',
+              '/usr/local/lib/python1.5/sharedmodules',
+              '/usr/local/lib/python1.5/tkinter'],
+          '',
+          '/usr/local/lib/python1.5',
+          '/usr/local/lib/python1.5/test',
+          '/usr/local/lib/python1.5/sunos5',
+          '/usr/local/lib/python1.5/sharedmodules',
+          '/usr/local/lib/python1.5/tkinter']
+      >>>
+      >>> import parser
+      >>> tup = parser.ast2tuple(
+      ...     parser.suite(open('pprint.py').read()))[1][1][1]
+      >>> pp = pprint.PrettyPrinter(depth=6)
+      >>> pp.pprint(tup)
+      (266, (267, (307, (287, (288, (...))))))
+
+The :class:`PrettyPrinter` class supports several derivative functions:
+
+.. % Now the derivative functions:
+
+
+.. function:: pformat(object[, indent[, width[, depth]]])
+
+   Return the formatted representation of *object* as a string.  *indent*, *width*
+   and *depth* will be passed to the :class:`PrettyPrinter` constructor as
+   formatting parameters.
+
+   .. versionchanged:: 2.4
+      The parameters *indent*, *width* and *depth* were added.
+
+
+.. function:: pprint(object[, stream[, indent[, width[, depth]]]])
+
+   Prints the formatted representation of *object* on *stream*, followed by a
+   newline.  If *stream* is omitted, ``sys.stdout`` is used.  This may be used in
+   the interactive interpreter instead of a :keyword:`print` statement for
+   inspecting values.    *indent*, *width* and *depth* will be passed to the
+   :class:`PrettyPrinter` constructor as formatting parameters. ::
+
+      >>> stuff = sys.path[:]
+      >>> stuff.insert(0, stuff)
+      >>> pprint.pprint(stuff)
+      [,
+       '',
+       '/usr/local/lib/python1.5',
+       '/usr/local/lib/python1.5/test',
+       '/usr/local/lib/python1.5/sunos5',
+       '/usr/local/lib/python1.5/sharedmodules',
+       '/usr/local/lib/python1.5/tkinter']
+
+   .. versionchanged:: 2.4
+      The parameters *indent*, *width* and *depth* were added.
+
+
+.. function:: isreadable(object)
+
+   .. index:: builtin: eval
+
+   Determine if the formatted representation of *object* is "readable," or can be
+   used to reconstruct the value using :func:`eval`.  This always returns ``False``
+   for recursive objects. ::
+
+      >>> pprint.isreadable(stuff)
+      False
+
+
+.. function:: isrecursive(object)
+
+   Determine if *object* requires a recursive representation.
+
+One more support function is also defined:
+
+
+.. function:: saferepr(object)
+
+   Return a string representation of *object*, protected against recursive data
+   structures.  If the representation of *object* exposes a recursive entry, the
+   recursive reference will be represented as ````.  The representation is not otherwise formatted.
+
+.. % This example is outside the {funcdesc} to keep it from running over
+.. % the right margin.
+
+::
+
+   >>> pprint.saferepr(stuff)
+   "[, '', '/usr/local/lib/python1.5', '/usr/loca
+   l/lib/python1.5/test', '/usr/local/lib/python1.5/sunos5', '/usr/local/lib/python
+   1.5/sharedmodules', '/usr/local/lib/python1.5/tkinter']"
+
+
+.. _prettyprinter-objects:
+
+PrettyPrinter Objects
+---------------------
+
+:class:`PrettyPrinter` instances have the following methods:
+
+
+.. method:: PrettyPrinter.pformat(object)
+
+   Return the formatted representation of *object*.  This takes into account the
+   options passed to the :class:`PrettyPrinter` constructor.
+
+
+.. method:: PrettyPrinter.pprint(object)
+
+   Print the formatted representation of *object* on the configured stream,
+   followed by a newline.
+
+The following methods provide the implementations for the corresponding
+functions of the same names.  Using these methods on an instance is slightly
+more efficient since new :class:`PrettyPrinter` objects don't need to be
+created.
+
+
+.. method:: PrettyPrinter.isreadable(object)
+
+   .. index:: builtin: eval
+
+   Determine if the formatted representation of the object is "readable," or can be
+   used to reconstruct the value using :func:`eval`.  Note that this returns
+   ``False`` for recursive objects.  If the *depth* parameter of the
+   :class:`PrettyPrinter` is set and the object is deeper than allowed, this
+   returns ``False``.
+
+
+.. method:: PrettyPrinter.isrecursive(object)
+
+   Determine if the object requires a recursive representation.
+
+This method is provided as a hook to allow subclasses to modify the way objects
+are converted to strings.  The default implementation uses the internals of the
+:func:`saferepr` implementation.
+
+
+.. method:: PrettyPrinter.format(object, context, maxlevels, level)
+
+   Returns three values: the formatted version of *object* as a string, a flag
+   indicating whether the result is readable, and a flag indicating whether
+   recursion was detected.  The first argument is the object to be presented.  The
+   second is a dictionary which contains the :func:`id` of objects that are part of
+   the current presentation context (direct and indirect containers for *object*
+   that are affecting the presentation) as the keys; if an object needs to be
+   presented which is already represented in *context*, the third return value
+   should be ``True``.  Recursive calls to the :meth:`format` method should add
+   additional entries for containers to this dictionary.  The third argument,
+   *maxlevels*, gives the requested limit to recursion; this will be ``0`` if there
+   is no requested limit.  This argument should be passed unmodified to recursive
+   calls. The fourth argument, *level*, gives the current level; recursive calls
+   should be passed a value less than that of the current call.
+
+   .. versionadded:: 2.3
+
diff --git a/Doc/library/profile.rst b/Doc/library/profile.rst
new file mode 100644
index 0000000..2ab24c5
--- /dev/null
+++ b/Doc/library/profile.rst
@@ -0,0 +1,682 @@
+
+.. _profile:
+
+********************
+The Python Profilers
+********************
+
+.. sectionauthor:: James Roskind
+
+
+.. index:: single: InfoSeek Corporation
+
+Copyright © 1994, by InfoSeek Corporation, all rights reserved.
+
+Written by James Roskind. [#]_
+
+Permission to use, copy, modify, and distribute this Python software and its
+associated documentation for any purpose (subject to the restriction in the
+following sentence) without fee is hereby granted, provided that the above
+copyright notice appears in all copies, and that both that copyright notice and
+this permission notice appear in supporting documentation, and that the name of
+InfoSeek not be used in advertising or publicity pertaining to distribution of
+the software without specific, written prior permission.  This permission is
+explicitly restricted to the copying and modification of the software to remain
+in Python, compiled Python, or other languages (such as C) wherein the modified
+or derived code is exclusively imported into a Python module.
+
+INFOSEEK CORPORATION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT
+SHALL INFOSEEK CORPORATION BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL
+DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+The profiler was written after only programming in Python for 3 weeks. As a
+result, it is probably clumsy code, but I don't know for sure yet 'cause I'm a
+beginner :-).  I did work hard to make the code run fast, so that profiling
+would be a reasonable thing to do.  I tried not to repeat code fragments, but
+I'm sure I did some stuff in really awkward ways at times.  Please send
+suggestions for improvements to: jar@netscape.com.  I won't promise *any*
+support.  ...but I'd appreciate the feedback.
+
+
+.. _profiler-introduction:
+
+Introduction to the profilers
+=============================
+
+.. index::
+   single: deterministic profiling
+   single: profiling, deterministic
+
+A :dfn:`profiler` is a program that describes the run time performance of a
+program, providing a variety of statistics.  This documentation describes the
+profiler functionality provided in the modules :mod:`profile` and :mod:`pstats`.
+This profiler provides :dfn:`deterministic profiling` of any Python programs.
+It also provides a series of report generation tools to allow users to rapidly
+examine the results of a profile operation.
+
+The Python standard library provides three different profilers:
+
+#. :mod:`profile`, a pure Python module, described in the sequel. Copyright ©
+   1994, by InfoSeek Corporation.
+
+   .. versionchanged:: 2.4
+      also reports the time spent in calls to built-in functions and methods.
+
+#. :mod:`cProfile`, a module written in C, with a reasonable overhead that makes
+   it suitable for profiling long-running programs. Based on :mod:`lsprof`,
+   contributed by Brett Rosen and Ted Czotter.
+
+   .. versionadded:: 2.5
+
+#. :mod:`hotshot`, a C module focusing on minimizing the overhead while
+   profiling, at the expense of long data post-processing times.
+
+   .. versionchanged:: 2.5
+      the results should be more meaningful than in the past: the timing core
+      contained a critical bug.
+
+The :mod:`profile` and :mod:`cProfile` modules export the same interface, so
+they are mostly interchangeables; :mod:`cProfile` has a much lower overhead but
+is not so far as well-tested and might not be available on all systems.
+:mod:`cProfile` is really a compatibility layer on top of the internal
+:mod:`_lsprof` module.  The :mod:`hotshot` module is reserved to specialized
+usages.
+
+.. % \section{How Is This Profiler Different From The Old Profiler?}
+.. % \nodename{Profiler Changes}
+.. % 
+.. % (This section is of historical importance only; the old profiler
+.. % discussed here was last seen in Python 1.1.)
+.. % 
+.. % The big changes from old profiling module are that you get more
+.. % information, and you pay less CPU time.  It's not a trade-off, it's a
+.. % trade-up.
+.. % 
+.. % To be specific:
+.. % 
+.. % \begin{description}
+.. % 
+.. % \item[Bugs removed:]
+.. % Local stack frame is no longer molested, execution time is now charged
+.. % to correct functions.
+.. % 
+.. % \item[Accuracy increased:]
+.. % Profiler execution time is no longer charged to user's code,
+.. % calibration for platform is supported, file reads are not done \emph{by}
+.. % profiler \emph{during} profiling (and charged to user's code!).
+.. % 
+.. % \item[Speed increased:]
+.. % Overhead CPU cost was reduced by more than a factor of two (perhaps a
+.. % factor of five), lightweight profiler module is all that must be
+.. % loaded, and the report generating module (\module{pstats}) is not needed
+.. % during profiling.
+.. % 
+.. % \item[Recursive functions support:]
+.. % Cumulative times in recursive functions are correctly calculated;
+.. % recursive entries are counted.
+.. % 
+.. % \item[Large growth in report generating UI:]
+.. % Distinct profiles runs can be added together forming a comprehensive
+.. % report; functions that import statistics take arbitrary lists of
+.. % files; sorting criteria is now based on keywords (instead of 4 integer
+.. % options); reports shows what functions were profiled as well as what
+.. % profile file was referenced; output format has been improved.
+.. % 
+.. % \end{description}
+
+
+.. _profile-instant:
+
+Instant User's Manual
+=====================
+
+This section is provided for users that "don't want to read the manual." It
+provides a very brief overview, and allows a user to rapidly perform profiling
+on an existing application.
+
+To profile an application with a main entry point of :func:`foo`, you would add
+the following to your module::
+
+   import cProfile
+   cProfile.run('foo()')
+
+(Use :mod:`profile` instead of :mod:`cProfile` if the latter is not available on
+your system.)
+
+The above action would cause :func:`foo` to be run, and a series of informative
+lines (the profile) to be printed.  The above approach is most useful when
+working with the interpreter.  If you would like to save the results of a
+profile into a file for later examination, you can supply a file name as the
+second argument to the :func:`run` function::
+
+   import cProfile
+   cProfile.run('foo()', 'fooprof')
+
+The file :file:`cProfile.py` can also be invoked as a script to profile another
+script.  For example::
+
+   python -m cProfile myscript.py
+
+:file:`cProfile.py` accepts two optional arguments on the command line::
+
+   cProfile.py [-o output_file] [-s sort_order]
+
+:option:`-s` only applies to standard output (:option:`-o` is not supplied).
+Look in the :class:`Stats` documentation for valid sort values.
+
+When you wish to review the profile, you should use the methods in the
+:mod:`pstats` module.  Typically you would load the statistics data as follows::
+
+   import pstats
+   p = pstats.Stats('fooprof')
+
+The class :class:`Stats` (the above code just created an instance of this class)
+has a variety of methods for manipulating and printing the data that was just
+read into ``p``.  When you ran :func:`cProfile.run` above, what was printed was
+the result of three method calls::
+
+   p.strip_dirs().sort_stats(-1).print_stats()
+
+The first method removed the extraneous path from all the module names. The
+second method sorted all the entries according to the standard module/line/name
+string that is printed. The third method printed out all the statistics.  You
+might try the following sort calls:
+
+.. % (this is to comply with the semantics of the old profiler).
+
+::
+
+   p.sort_stats('name')
+   p.print_stats()
+
+The first call will actually sort the list by function name, and the second call
+will print out the statistics.  The following are some interesting calls to
+experiment with::
+
+   p.sort_stats('cumulative').print_stats(10)
+
+This sorts the profile by cumulative time in a function, and then only prints
+the ten most significant lines.  If you want to understand what algorithms are
+taking time, the above line is what you would use.
+
+If you were looking to see what functions were looping a lot, and taking a lot
+of time, you would do::
+
+   p.sort_stats('time').print_stats(10)
+
+to sort according to time spent within each function, and then print the
+statistics for the top ten functions.
+
+You might also try::
+
+   p.sort_stats('file').print_stats('__init__')
+
+This will sort all the statistics by file name, and then print out statistics
+for only the class init methods (since they are spelled with ``__init__`` in
+them).  As one final example, you could try::
+
+   p.sort_stats('time', 'cum').print_stats(.5, 'init')
+
+This line sorts statistics with a primary key of time, and a secondary key of
+cumulative time, and then prints out some of the statistics. To be specific, the
+list is first culled down to 50% (re: ``.5``) of its original size, then only
+lines containing ``init`` are maintained, and that sub-sub-list is printed.
+
+If you wondered what functions called the above functions, you could now (``p``
+is still sorted according to the last criteria) do::
+
+   p.print_callers(.5, 'init')
+
+and you would get a list of callers for each of the listed functions.
+
+If you want more functionality, you're going to have to read the manual, or
+guess what the following functions do::
+
+   p.print_callees()
+   p.add('fooprof')
+
+Invoked as a script, the :mod:`pstats` module is a statistics browser for
+reading and examining profile dumps.  It has a simple line-oriented interface
+(implemented using :mod:`cmd`) and interactive help.
+
+
+.. _deterministic-profiling:
+
+What Is Deterministic Profiling?
+================================
+
+:dfn:`Deterministic profiling` is meant to reflect the fact that all *function
+call*, *function return*, and *exception* events are monitored, and precise
+timings are made for the intervals between these events (during which time the
+user's code is executing).  In contrast, :dfn:`statistical profiling` (which is
+not done by this module) randomly samples the effective instruction pointer, and
+deduces where time is being spent.  The latter technique traditionally involves
+less overhead (as the code does not need to be instrumented), but provides only
+relative indications of where time is being spent.
+
+In Python, since there is an interpreter active during execution, the presence
+of instrumented code is not required to do deterministic profiling.  Python
+automatically provides a :dfn:`hook` (optional callback) for each event.  In
+addition, the interpreted nature of Python tends to add so much overhead to
+execution, that deterministic profiling tends to only add small processing
+overhead in typical applications.  The result is that deterministic profiling is
+not that expensive, yet provides extensive run time statistics about the
+execution of a Python program.
+
+Call count statistics can be used to identify bugs in code (surprising counts),
+and to identify possible inline-expansion points (high call counts).  Internal
+time statistics can be used to identify "hot loops" that should be carefully
+optimized.  Cumulative time statistics should be used to identify high level
+errors in the selection of algorithms.  Note that the unusual handling of
+cumulative times in this profiler allows statistics for recursive
+implementations of algorithms to be directly compared to iterative
+implementations.
+
+
+Reference Manual -- :mod:`profile` and :mod:`cProfile`
+======================================================
+
+.. module:: cProfile
+   :synopsis: Python profiler
+
+
+The primary entry point for the profiler is the global function
+:func:`profile.run` (resp. :func:`cProfile.run`). It is typically used to create
+any profile information.  The reports are formatted and printed using methods of
+the class :class:`pstats.Stats`.  The following is a description of all of these
+standard entry points and functions.  For a more in-depth view of some of the
+code, consider reading the later section on Profiler Extensions, which includes
+discussion of how to derive "better" profilers from the classes presented, or
+reading the source code for these modules.
+
+
+.. function:: run(command[, filename])
+
+   This function takes a single argument that can be passed to the :func:`exec`
+   function, and an optional file name.  In all cases this routine attempts to
+   :func:`exec` its first argument, and gather profiling statistics from the
+   execution. If no file name is present, then this function automatically
+   prints a simple profiling report, sorted by the standard name string
+   (file/line/function-name) that is presented in each line.  The following is a
+   typical output from such a call::
+
+            2706 function calls (2004 primitive calls) in 4.504 CPU seconds
+
+      Ordered by: standard name
+
+      ncalls  tottime  percall  cumtime  percall filename:lineno(function)
+           2    0.006    0.003    0.953    0.477 pobject.py:75(save_objects)
+        43/3    0.533    0.012    0.749    0.250 pobject.py:99(evaluate)
+       ...
+
+   The first line indicates that 2706 calls were monitored.  Of those calls, 2004
+   were :dfn:`primitive`.  We define :dfn:`primitive` to mean that the call was not
+   induced via recursion. The next line: ``Ordered by: standard name``, indicates
+   that the text string in the far right column was used to sort the output. The
+   column headings include:
+
+   ncalls 
+      for the number of calls,
+
+   tottime 
+      for the total time spent in the given function (and excluding time made in calls
+      to sub-functions),
+
+   percall 
+      is the quotient of ``tottime`` divided by ``ncalls``
+
+   cumtime 
+      is the total time spent in this and all subfunctions (from invocation till
+      exit). This figure is accurate *even* for recursive functions.
+
+   percall 
+      is the quotient of ``cumtime`` divided by primitive calls
+
+   filename:lineno(function) 
+      provides the respective data of each function
+
+   When there are two numbers in the first column (for example, ``43/3``), then the
+   latter is the number of primitive calls, and the former is the actual number of
+   calls.  Note that when the function does not recurse, these two values are the
+   same, and only the single figure is printed.
+
+
+.. function:: runctx(command, globals, locals[, filename])
+
+   This function is similar to :func:`run`, with added arguments to supply the
+   globals and locals dictionaries for the *command* string.
+
+Analysis of the profiler data is done using the :class:`Stats` class.
+
+.. note::
+
+   The :class:`Stats` class is defined in the :mod:`pstats` module.
+
+
+.. module:: pstats
+   :synopsis: Statistics object for use with the profiler.
+
+
+.. class:: Stats(filename[, stream=sys.stdout[, ...]])
+
+   This class constructor creates an instance of a "statistics object" from a
+   *filename* (or set of filenames).  :class:`Stats` objects are manipulated by
+   methods, in order to print useful reports.  You may specify an alternate output
+   stream by giving the keyword argument, ``stream``.
+
+   The file selected by the above constructor must have been created by the
+   corresponding version of :mod:`profile` or :mod:`cProfile`.  To be specific,
+   there is *no* file compatibility guaranteed with future versions of this
+   profiler, and there is no compatibility with files produced by other profilers.
+   If several files are provided, all the statistics for identical functions will
+   be coalesced, so that an overall view of several processes can be considered in
+   a single report.  If additional files need to be combined with data in an
+   existing :class:`Stats` object, the :meth:`add` method can be used.
+
+   .. % (such as the old system profiler).
+
+   .. versionchanged:: 2.5
+      The *stream* parameter was added.
+
+
+.. _profile-stats:
+
+The :class:`Stats` Class
+------------------------
+
+:class:`Stats` objects have the following methods:
+
+
+.. method:: Stats.strip_dirs()
+
+   This method for the :class:`Stats` class removes all leading path information
+   from file names.  It is very useful in reducing the size of the printout to fit
+   within (close to) 80 columns.  This method modifies the object, and the stripped
+   information is lost.  After performing a strip operation, the object is
+   considered to have its entries in a "random" order, as it was just after object
+   initialization and loading.  If :meth:`strip_dirs` causes two function names to
+   be indistinguishable (they are on the same line of the same filename, and have
+   the same function name), then the statistics for these two entries are
+   accumulated into a single entry.
+
+
+.. method:: Stats.add(filename[, ...])
+
+   This method of the :class:`Stats` class accumulates additional profiling
+   information into the current profiling object.  Its arguments should refer to
+   filenames created by the corresponding version of :func:`profile.run` or
+   :func:`cProfile.run`. Statistics for identically named (re: file, line, name)
+   functions are automatically accumulated into single function statistics.
+
+
+.. method:: Stats.dump_stats(filename)
+
+   Save the data loaded into the :class:`Stats` object to a file named *filename*.
+   The file is created if it does not exist, and is overwritten if it already
+   exists.  This is equivalent to the method of the same name on the
+   :class:`profile.Profile` and :class:`cProfile.Profile` classes.
+
+   .. versionadded:: 2.3
+
+
+.. method:: Stats.sort_stats(key[, ...])
+
+   This method modifies the :class:`Stats` object by sorting it according to the
+   supplied criteria.  The argument is typically a string identifying the basis of
+   a sort (example: ``'time'`` or ``'name'``).
+
+   When more than one key is provided, then additional keys are used as secondary
+   criteria when there is equality in all keys selected before them.  For example,
+   ``sort_stats('name', 'file')`` will sort all the entries according to their
+   function name, and resolve all ties (identical function names) by sorting by
+   file name.
+
+   Abbreviations can be used for any key names, as long as the abbreviation is
+   unambiguous.  The following are the keys currently defined:
+
+   +------------------+----------------------+
+   | Valid Arg        | Meaning              |
+   +==================+======================+
+   | ``'calls'``      | call count           |
+   +------------------+----------------------+
+   | ``'cumulative'`` | cumulative time      |
+   +------------------+----------------------+
+   | ``'file'``       | file name            |
+   +------------------+----------------------+
+   | ``'module'``     | file name            |
+   +------------------+----------------------+
+   | ``'pcalls'``     | primitive call count |
+   +------------------+----------------------+
+   | ``'line'``       | line number          |
+   +------------------+----------------------+
+   | ``'name'``       | function name        |
+   +------------------+----------------------+
+   | ``'nfl'``        | name/file/line       |
+   +------------------+----------------------+
+   | ``'stdname'``    | standard name        |
+   +------------------+----------------------+
+   | ``'time'``       | internal time        |
+   +------------------+----------------------+
+
+   Note that all sorts on statistics are in descending order (placing most time
+   consuming items first), where as name, file, and line number searches are in
+   ascending order (alphabetical). The subtle distinction between ``'nfl'`` and
+   ``'stdname'`` is that the standard name is a sort of the name as printed, which
+   means that the embedded line numbers get compared in an odd way.  For example,
+   lines 3, 20, and 40 would (if the file names were the same) appear in the string
+   order 20, 3 and 40.  In contrast, ``'nfl'`` does a numeric compare of the line
+   numbers.  In fact, ``sort_stats('nfl')`` is the same as ``sort_stats('name',
+   'file', 'line')``.
+
+   For backward-compatibility reasons, the numeric arguments ``-1``, ``0``, ``1``,
+   and ``2`` are permitted.  They are interpreted as ``'stdname'``, ``'calls'``,
+   ``'time'``, and ``'cumulative'`` respectively.  If this old style format
+   (numeric) is used, only one sort key (the numeric key) will be used, and
+   additional arguments will be silently ignored.
+
+   .. % For compatibility with the old profiler,
+
+
+.. method:: Stats.reverse_order()
+
+   This method for the :class:`Stats` class reverses the ordering of the basic list
+   within the object.  Note that by default ascending vs descending order is
+   properly selected based on the sort key of choice.
+
+   .. % This method is provided primarily for
+   .. % compatibility with the old profiler.
+
+
+.. method:: Stats.print_stats([restriction, ...])
+
+   This method for the :class:`Stats` class prints out a report as described in the
+   :func:`profile.run` definition.
+
+   The order of the printing is based on the last :meth:`sort_stats` operation done
+   on the object (subject to caveats in :meth:`add` and :meth:`strip_dirs`).
+
+   The arguments provided (if any) can be used to limit the list down to the
+   significant entries.  Initially, the list is taken to be the complete set of
+   profiled functions.  Each restriction is either an integer (to select a count of
+   lines), or a decimal fraction between 0.0 and 1.0 inclusive (to select a
+   percentage of lines), or a regular expression (to pattern match the standard
+   name that is printed; as of Python 1.5b1, this uses the Perl-style regular
+   expression syntax defined by the :mod:`re` module).  If several restrictions are
+   provided, then they are applied sequentially.  For example::
+
+      print_stats(.1, 'foo:')
+
+   would first limit the printing to first 10% of list, and then only print
+   functions that were part of filename :file:`.\*foo:`.  In contrast, the
+   command::
+
+      print_stats('foo:', .1)
+
+   would limit the list to all functions having file names :file:`.\*foo:`, and
+   then proceed to only print the first 10% of them.
+
+
+.. method:: Stats.print_callers([restriction, ...])
+
+   This method for the :class:`Stats` class prints a list of all functions that
+   called each function in the profiled database.  The ordering is identical to
+   that provided by :meth:`print_stats`, and the definition of the restricting
+   argument is also identical.  Each caller is reported on its own line.  The
+   format differs slightly depending on the profiler that produced the stats:
+
+   * With :mod:`profile`, a number is shown in parentheses after each caller to
+     show how many times this specific call was made.  For convenience, a second
+     non-parenthesized number repeats the cumulative time spent in the function
+     at the right.
+
+   * With :mod:`cProfile`, each caller is preceeded by three numbers: the number of
+     times this specific call was made, and the total and cumulative times spent in
+     the current function while it was invoked by this specific caller.
+
+
+.. method:: Stats.print_callees([restriction, ...])
+
+   This method for the :class:`Stats` class prints a list of all function that were
+   called by the indicated function.  Aside from this reversal of direction of
+   calls (re: called vs was called by), the arguments and ordering are identical to
+   the :meth:`print_callers` method.
+
+
+.. _profile-limits:
+
+Limitations
+===========
+
+One limitation has to do with accuracy of timing information. There is a
+fundamental problem with deterministic profilers involving accuracy.  The most
+obvious restriction is that the underlying "clock" is only ticking at a rate
+(typically) of about .001 seconds.  Hence no measurements will be more accurate
+than the underlying clock.  If enough measurements are taken, then the "error"
+will tend to average out. Unfortunately, removing this first error induces a
+second source of error.
+
+The second problem is that it "takes a while" from when an event is dispatched
+until the profiler's call to get the time actually *gets* the state of the
+clock.  Similarly, there is a certain lag when exiting the profiler event
+handler from the time that the clock's value was obtained (and then squirreled
+away), until the user's code is once again executing.  As a result, functions
+that are called many times, or call many functions, will typically accumulate
+this error. The error that accumulates in this fashion is typically less than
+the accuracy of the clock (less than one clock tick), but it *can* accumulate
+and become very significant.
+
+The problem is more important with :mod:`profile` than with the lower-overhead
+:mod:`cProfile`.  For this reason, :mod:`profile` provides a means of
+calibrating itself for a given platform so that this error can be
+probabilistically (on the average) removed. After the profiler is calibrated, it
+will be more accurate (in a least square sense), but it will sometimes produce
+negative numbers (when call counts are exceptionally low, and the gods of
+probability work against you :-). )  Do *not* be alarmed by negative numbers in
+the profile.  They should *only* appear if you have calibrated your profiler,
+and the results are actually better than without calibration.
+
+
+.. _profile-calibration:
+
+Calibration
+===========
+
+The profiler of the :mod:`profile` module subtracts a constant from each event
+handling time to compensate for the overhead of calling the time function, and
+socking away the results.  By default, the constant is 0. The following
+procedure can be used to obtain a better constant for a given platform (see
+discussion in section Limitations above). ::
+
+   import profile
+   pr = profile.Profile()
+   for i in range(5):
+       print pr.calibrate(10000)
+
+The method executes the number of Python calls given by the argument, directly
+and again under the profiler, measuring the time for both. It then computes the
+hidden overhead per profiler event, and returns that as a float.  For example,
+on an 800 MHz Pentium running Windows 2000, and using Python's time.clock() as
+the timer, the magical number is about 12.5e-6.
+
+The object of this exercise is to get a fairly consistent result. If your
+computer is *very* fast, or your timer function has poor resolution, you might
+have to pass 100000, or even 1000000, to get consistent results.
+
+When you have a consistent answer, there are three ways you can use it: [#]_ ::
+
+   import profile
+
+   # 1. Apply computed bias to all Profile instances created hereafter.
+   profile.Profile.bias = your_computed_bias
+
+   # 2. Apply computed bias to a specific Profile instance.
+   pr = profile.Profile()
+   pr.bias = your_computed_bias
+
+   # 3. Specify computed bias in instance constructor.
+   pr = profile.Profile(bias=your_computed_bias)
+
+If you have a choice, you are better off choosing a smaller constant, and then
+your results will "less often" show up as negative in profile statistics.
+
+
+.. _profiler-extensions:
+
+Extensions --- Deriving Better Profilers
+========================================
+
+The :class:`Profile` class of both modules, :mod:`profile` and :mod:`cProfile`,
+were written so that derived classes could be developed to extend the profiler.
+The details are not described here, as doing this successfully requires an
+expert understanding of how the :class:`Profile` class works internally.  Study
+the source code of the module carefully if you want to pursue this.
+
+If all you want to do is change how current time is determined (for example, to
+force use of wall-clock time or elapsed process time), pass the timing function
+you want to the :class:`Profile` class constructor::
+
+   pr = profile.Profile(your_time_func)
+
+The resulting profiler will then call :func:`your_time_func`.
+
+:class:`profile.Profile`
+   :func:`your_time_func` should return a single number, or a list of numbers whose
+   sum is the current time (like what :func:`os.times` returns).  If the function
+   returns a single time number, or the list of returned numbers has length 2, then
+   you will get an especially fast version of the dispatch routine.
+
+   Be warned that you should calibrate the profiler class for the timer function
+   that you choose.  For most machines, a timer that returns a lone integer value
+   will provide the best results in terms of low overhead during profiling.
+   (:func:`os.times` is *pretty* bad, as it returns a tuple of floating point
+   values).  If you want to substitute a better timer in the cleanest fashion,
+   derive a class and hardwire a replacement dispatch method that best handles your
+   timer call, along with the appropriate calibration constant.
+
+:class:`cProfile.Profile`
+   :func:`your_time_func` should return a single number.  If it returns plain
+   integers, you can also invoke the class constructor with a second argument
+   specifying the real duration of one unit of time.  For example, if
+   :func:`your_integer_time_func` returns times measured in thousands of seconds,
+   you would constuct the :class:`Profile` instance as follows::
+
+      pr = profile.Profile(your_integer_time_func, 0.001)
+
+   As the :mod:`cProfile.Profile` class cannot be calibrated, custom timer
+   functions should be used with care and should be as fast as possible.  For the
+   best results with a custom timer, it might be necessary to hard-code it in the C
+   source of the internal :mod:`_lsprof` module.
+
+.. rubric:: Footnotes
+
+.. [#] Updated and converted to LaTeX by Guido van Rossum. Further updated by Armin
+   Rigo to integrate the documentation for the new :mod:`cProfile` module of Python
+   2.5.
+
+.. [#] Prior to Python 2.2, it was necessary to edit the profiler source code to embed
+   the bias as a literal number.  You still can, but that method is no longer
+   described, because no longer needed.
+
diff --git a/Doc/library/pty.rst b/Doc/library/pty.rst
new file mode 100644
index 0000000..5e1da22
--- /dev/null
+++ b/Doc/library/pty.rst
@@ -0,0 +1,48 @@
+
+:mod:`pty` --- Pseudo-terminal utilities
+========================================
+
+.. module:: pty
+   :platform: IRIX, Linux
+   :synopsis: Pseudo-Terminal Handling for SGI and Linux.
+.. moduleauthor:: Steen Lumholt
+.. sectionauthor:: Moshe Zadka 
+
+
+The :mod:`pty` module defines operations for handling the pseudo-terminal
+concept: starting another process and being able to write to and read from its
+controlling terminal programmatically.
+
+Because pseudo-terminal handling is highly platform dependant, there is code to
+do it only for SGI and Linux. (The Linux code is supposed to work on other
+platforms, but hasn't been tested yet.)
+
+The :mod:`pty` module defines the following functions:
+
+
+.. function:: fork()
+
+   Fork. Connect the child's controlling terminal to a pseudo-terminal. Return
+   value is ``(pid, fd)``. Note that the child  gets *pid* 0, and the *fd* is
+   *invalid*. The parent's return value is the *pid* of the child, and *fd* is a
+   file descriptor connected to the child's controlling terminal (and also to the
+   child's standard input and output).
+
+
+.. function:: openpty()
+
+   Open a new pseudo-terminal pair, using :func:`os.openpty` if possible, or
+   emulation code for SGI and generic Unix systems. Return a pair of file
+   descriptors ``(master, slave)``, for the master and the slave end, respectively.
+
+
+.. function:: spawn(argv[, master_read[, stdin_read]])
+
+   Spawn a process, and connect its controlling terminal with the current
+   process's standard io. This is often used to baffle programs which insist on
+   reading from the controlling terminal.
+
+   The functions *master_read* and *stdin_read* should be functions which read from
+   a file-descriptor. The defaults try to read 1024 bytes each time they are
+   called.
+
diff --git a/Doc/library/pwd.rst b/Doc/library/pwd.rst
new file mode 100644
index 0000000..562afd9
--- /dev/null
+++ b/Doc/library/pwd.rst
@@ -0,0 +1,76 @@
+
+:mod:`pwd` --- The password database
+====================================
+
+.. module:: pwd
+   :platform: Unix
+   :synopsis: The password database (getpwnam() and friends).
+
+
+This module provides access to the Unix user account and password database.  It
+is available on all Unix versions.
+
+Password database entries are reported as a tuple-like object, whose attributes
+correspond to the members of the ``passwd`` structure (Attribute field below,
+see ````):
+
++-------+---------------+-----------------------------+
+| Index | Attribute     | Meaning                     |
++=======+===============+=============================+
+| 0     | ``pw_name``   | Login name                  |
++-------+---------------+-----------------------------+
+| 1     | ``pw_passwd`` | Optional encrypted password |
++-------+---------------+-----------------------------+
+| 2     | ``pw_uid``    | Numerical user ID           |
++-------+---------------+-----------------------------+
+| 3     | ``pw_gid``    | Numerical group ID          |
++-------+---------------+-----------------------------+
+| 4     | ``pw_gecos``  | User name or comment field  |
++-------+---------------+-----------------------------+
+| 5     | ``pw_dir``    | User home directory         |
++-------+---------------+-----------------------------+
+| 6     | ``pw_shell``  | User command interpreter    |
++-------+---------------+-----------------------------+
+
+The uid and gid items are integers, all others are strings. :exc:`KeyError` is
+raised if the entry asked for cannot be found.
+
+.. note::
+
+   .. index:: module: crypt
+
+   In traditional Unix the field ``pw_passwd`` usually contains a password
+   encrypted with a DES derived algorithm (see module :mod:`crypt`).  However most
+   modern unices  use a so-called *shadow password* system.  On those unices the
+   *pw_passwd* field only contains an asterisk (``'*'``) or the  letter ``'x'``
+   where the encrypted password is stored in a file :file:`/etc/shadow` which is
+   not world readable.  Whether the *pw_passwd* field contains anything useful is
+   system-dependent.  If available, the :mod:`spwd` module should be used where
+   access to the encrypted password is required.
+
+It defines the following items:
+
+
+.. function:: getpwuid(uid)
+
+   Return the password database entry for the given numeric user ID.
+
+
+.. function:: getpwnam(name)
+
+   Return the password database entry for the given user name.
+
+
+.. function:: getpwall()
+
+   Return a list of all available password database entries, in arbitrary order.
+
+
+.. seealso::
+
+   Module :mod:`grp`
+      An interface to the group database, similar to this.
+
+   Module :mod:`spwd`
+      An interface to the shadow password database, similar to this.
+
diff --git a/Doc/library/py_compile.rst b/Doc/library/py_compile.rst
new file mode 100644
index 0000000..c815846
--- /dev/null
+++ b/Doc/library/py_compile.rst
@@ -0,0 +1,55 @@
+:mod:`py_compile` --- Compile Python source files
+=================================================
+
+.. module:: py_compile
+   :synopsis: Generate byte-code files from Python source files.
+
+.. % Documentation based on module docstrings, by Fred L. Drake, Jr.
+.. % 
+
+
+
+.. index:: pair: file; byte-code
+
+The :mod:`py_compile` module provides a function to generate a byte-code file
+from a source file, and another function used when the module source file is
+invoked as a script.
+
+Though not often needed, this function can be useful when installing modules for
+shared use, especially if some of the users may not have permission to write the
+byte-code cache files in the directory containing the source code.
+
+
+.. exception:: PyCompileError
+
+   Exception raised when an error occurs while attempting to compile the file.
+
+
+.. function:: compile(file[, cfile[, dfile[, doraise]]])
+
+   Compile a source file to byte-code and write out the byte-code cache  file.  The
+   source code is loaded from the file name *file*.  The  byte-code is written to
+   *cfile*, which defaults to *file* ``+`` ``'c'`` (``'o'`` if optimization is
+   enabled in the current interpreter).  If *dfile* is specified, it is used as the
+   name of the source file in error messages instead of *file*.  If *doraise* is
+   true, a :exc:`PyCompileError` is raised when an error is encountered while
+   compiling *file*. If *doraise* is false (the default), an error string is
+   written to ``sys.stderr``, but no exception is raised.
+
+
+.. function:: main([args])
+
+   Compile several source files.  The files named in *args* (or on the command
+   line, if *args* is not specified) are compiled and the resulting bytecode is
+   cached in the normal manner.  This function does not search a directory
+   structure to locate source files; it only compiles files named explicitly.
+
+When this module is run as a script, the :func:`main` is used to compile all the
+files named on the command line.
+
+
+.. seealso::
+
+   Module :mod:`compileall`
+      Utilities to compile all Python source files in a directory tree.
+
diff --git a/Doc/library/pyclbr.rst b/Doc/library/pyclbr.rst
new file mode 100644
index 0000000..5a77b4e
--- /dev/null
+++ b/Doc/library/pyclbr.rst
@@ -0,0 +1,112 @@
+
+:mod:`pyclbr` --- Python class browser support
+==============================================
+
+.. module:: pyclbr
+   :synopsis: Supports information extraction for a Python class browser.
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+The :mod:`pyclbr` can be used to determine some limited information about the
+classes, methods and top-level functions defined in a module.  The information
+provided is sufficient to implement a traditional three-pane class browser.  The
+information is extracted from the source code rather than by importing the
+module, so this module is safe to use with untrusted source code.  This
+restriction makes it impossible to use this module with modules not implemented
+in Python, including many standard and optional extension modules.
+
+
+.. function:: readmodule(module[, path])
+
+   Read a module and return a dictionary mapping class names to class descriptor
+   objects.  The parameter *module* should be the name of a module as a string; it
+   may be the name of a module within a package.  The *path* parameter should be a
+   sequence, and is used to augment the value of ``sys.path``, which is used to
+   locate module source code.
+
+   .. % The 'inpackage' parameter appears to be for internal use only....
+
+
+.. function:: readmodule_ex(module[, path])
+
+   Like :func:`readmodule`, but the returned dictionary, in addition to mapping
+   class names to class descriptor objects, also maps top-level function names to
+   function descriptor objects.  Moreover, if the module being read is a package,
+   the key ``'__path__'`` in the returned dictionary has as its value a list which
+   contains the package search path.
+
+   .. % The 'inpackage' parameter appears to be for internal use only....
+
+
+.. _pyclbr-class-objects:
+
+Class Descriptor Objects
+------------------------
+
+The class descriptor objects used as values in the dictionary returned by
+:func:`readmodule` and :func:`readmodule_ex` provide the following data members:
+
+
+.. attribute:: class_descriptor.module
+
+   The name of the module defining the class described by the class descriptor.
+
+
+.. attribute:: class_descriptor.name
+
+   The name of the class.
+
+
+.. attribute:: class_descriptor.super
+
+   A list of class descriptors which describe the immediate base classes of the
+   class being described.  Classes which are named as superclasses but which are
+   not discoverable by :func:`readmodule` are listed as a string with the class
+   name instead of class descriptors.
+
+
+.. attribute:: class_descriptor.methods
+
+   A dictionary mapping method names to line numbers.
+
+
+.. attribute:: class_descriptor.file
+
+   Name of the file containing the ``class`` statement defining the class.
+
+
+.. attribute:: class_descriptor.lineno
+
+   The line number of the ``class`` statement within the file named by
+   :attr:`file`.
+
+
+.. _pyclbr-function-objects:
+
+Function Descriptor Objects
+---------------------------
+
+The function descriptor objects used as values in the dictionary returned by
+:func:`readmodule_ex` provide the following data members:
+
+
+.. attribute:: function_descriptor.module
+
+   The name of the module defining the function described by the function
+   descriptor.
+
+
+.. attribute:: function_descriptor.name
+
+   The name of the function.
+
+
+.. attribute:: function_descriptor.file
+
+   Name of the file containing the ``def`` statement defining the function.
+
+
+.. attribute:: function_descriptor.lineno
+
+   The line number of the ``def`` statement within the file named by :attr:`file`.
+
diff --git a/Doc/library/pydoc.rst b/Doc/library/pydoc.rst
new file mode 100644
index 0000000..2df127c
--- /dev/null
+++ b/Doc/library/pydoc.rst
@@ -0,0 +1,65 @@
+
+:mod:`pydoc` --- Documentation generator and online help system
+===============================================================
+
+.. module:: pydoc
+   :synopsis: Documentation generator and online help system.
+.. moduleauthor:: Ka-Ping Yee 
+.. sectionauthor:: Ka-Ping Yee 
+
+
+.. versionadded:: 2.1
+
+.. index::
+   single: documentation; generation
+   single: documentation; online
+   single: help; online
+
+The :mod:`pydoc` module automatically generates documentation from Python
+modules.  The documentation can be presented as pages of text on the console,
+served to a Web browser, or saved to HTML files.
+
+The built-in function :func:`help` invokes the online help system in the
+interactive interpreter, which uses :mod:`pydoc` to generate its documentation
+as text on the console.  The same text documentation can also be viewed from
+outside the Python interpreter by running :program:`pydoc` as a script at the
+operating system's command prompt. For example, running ::
+
+   pydoc sys
+
+at a shell prompt will display documentation on the :mod:`sys` module, in a
+style similar to the manual pages shown by the Unix :program:`man` command.  The
+argument to :program:`pydoc` can be the name of a function, module, or package,
+or a dotted reference to a class, method, or function within a module or module
+in a package.  If the argument to :program:`pydoc` looks like a path (that is,
+it contains the path separator for your operating system, such as a slash in
+Unix), and refers to an existing Python source file, then documentation is
+produced for that file.
+
+Specifying a :option:`-w` flag before the argument will cause HTML documentation
+to be written out to a file in the current directory, instead of displaying text
+on the console.
+
+Specifying a :option:`-k` flag before the argument will search the synopsis
+lines of all available modules for the keyword given as the argument, again in a
+manner similar to the Unix :program:`man` command.  The synopsis line of a
+module is the first line of its documentation string.
+
+You can also use :program:`pydoc` to start an HTTP server on the local machine
+that will serve documentation to visiting Web browsers. :program:`pydoc`
+:option:`-p 1234` will start a HTTP server on port 1234, allowing you to browse
+the documentation at ``http://localhost:1234/`` in your preferred Web browser.
+:program:`pydoc` :option:`-g` will start the server and additionally bring up a
+small :mod:`Tkinter`\ -based graphical interface to help you search for
+documentation pages.
+
+When :program:`pydoc` generates documentation, it uses the current environment
+and path to locate modules.  Thus, invoking :program:`pydoc` :option:`spam`
+documents precisely the version of the module you would get if you started the
+Python interpreter and typed ``import spam``.
+
+Module docs for core modules are assumed to reside in
+http://www.python.org/doc/current/lib/.  This can be overridden by setting the
+:envvar:`PYTHONDOCS` environment variable to a different URL or to a local
+directory containing the Library Reference Manual pages.
+
diff --git a/Doc/library/pyexpat.rst b/Doc/library/pyexpat.rst
new file mode 100644
index 0000000..87ed501
--- /dev/null
+++ b/Doc/library/pyexpat.rst
@@ -0,0 +1,873 @@
+
+:mod:`xml.parsers.expat` --- Fast XML parsing using Expat
+=========================================================
+
+.. module:: xml.parsers.expat
+   :synopsis: An interface to the Expat non-validating XML parser.
+.. moduleauthor:: Paul Prescod 
+
+
+.. % Markup notes:
+.. % 
+.. % Many of the attributes of the XMLParser objects are callbacks.
+.. % Since signature information must be presented, these are described
+.. % using the methoddesc environment.  Since they are attributes which
+.. % are set by client code, in-text references to these attributes
+.. % should be marked using the \member macro and should not include the
+.. % parentheses used when marking functions and methods.
+
+.. versionadded:: 2.0
+
+.. index:: single: Expat
+
+The :mod:`xml.parsers.expat` module is a Python interface to the Expat
+non-validating XML parser. The module provides a single extension type,
+:class:`xmlparser`, that represents the current state of an XML parser.  After
+an :class:`xmlparser` object has been created, various attributes of the object
+can be set to handler functions.  When an XML document is then fed to the
+parser, the handler functions are called for the character data and markup in
+the XML document.
+
+.. index:: module: pyexpat
+
+This module uses the :mod:`pyexpat` module to provide access to the Expat
+parser.  Direct use of the :mod:`pyexpat` module is deprecated.
+
+This module provides one exception and one type object:
+
+
+.. exception:: ExpatError
+
+   The exception raised when Expat reports an error.  See section
+   :ref:`expaterror-objects` for more information on interpreting Expat errors.
+
+
+.. exception:: error
+
+   Alias for :exc:`ExpatError`.
+
+
+.. data:: XMLParserType
+
+   The type of the return values from the :func:`ParserCreate` function.
+
+The :mod:`xml.parsers.expat` module contains two functions:
+
+
+.. function:: ErrorString(errno)
+
+   Returns an explanatory string for a given error number *errno*.
+
+
+.. function:: ParserCreate([encoding[, namespace_separator]])
+
+   Creates and returns a new :class:`xmlparser` object.   *encoding*, if specified,
+   must be a string naming the encoding  used by the XML data.  Expat doesn't
+   support as many encodings as Python does, and its repertoire of encodings can't
+   be extended; it supports UTF-8, UTF-16, ISO-8859-1 (Latin1), and ASCII.  If
+   *encoding* is given it will override the implicit or explicit encoding of the
+   document.
+
+   Expat can optionally do XML namespace processing for you, enabled by providing a
+   value for *namespace_separator*.  The value must be a one-character string; a
+   :exc:`ValueError` will be raised if the string has an illegal length (``None``
+   is considered the same as omission).  When namespace processing is enabled,
+   element type names and attribute names that belong to a namespace will be
+   expanded.  The element name passed to the element handlers
+   :attr:`StartElementHandler` and :attr:`EndElementHandler` will be the
+   concatenation of the namespace URI, the namespace separator character, and the
+   local part of the name.  If the namespace separator is a zero byte (``chr(0)``)
+   then the namespace URI and the local part will be concatenated without any
+   separator.
+
+   For example, if *namespace_separator* is set to a space character (``' '``) and
+   the following document is parsed::
+
+      
+      
+        
+        
+      
+
+   :attr:`StartElementHandler` will receive the following strings for each
+   element::
+
+      http://default-namespace.org/ root
+      http://www.python.org/ns/ elem1
+      elem2
+
+
+.. seealso::
+
+   `The Expat XML Parser `_
+      Home page of the Expat project.
+
+
+.. _xmlparser-objects:
+
+XMLParser Objects
+-----------------
+
+:class:`xmlparser` objects have the following methods:
+
+
+.. method:: xmlparser.Parse(data[, isfinal])
+
+   Parses the contents of the string *data*, calling the appropriate handler
+   functions to process the parsed data.  *isfinal* must be true on the final call
+   to this method.  *data* can be the empty string at any time.
+
+
+.. method:: xmlparser.ParseFile(file)
+
+   Parse XML data reading from the object *file*.  *file* only needs to provide
+   the ``read(nbytes)`` method, returning the empty string when there's no more
+   data.
+
+
+.. method:: xmlparser.SetBase(base)
+
+   Sets the base to be used for resolving relative URIs in system identifiers in
+   declarations.  Resolving relative identifiers is left to the application: this
+   value will be passed through as the *base* argument to the
+   :func:`ExternalEntityRefHandler`, :func:`NotationDeclHandler`, and
+   :func:`UnparsedEntityDeclHandler` functions.
+
+
+.. method:: xmlparser.GetBase()
+
+   Returns a string containing the base set by a previous call to :meth:`SetBase`,
+   or ``None`` if  :meth:`SetBase` hasn't been called.
+
+
+.. method:: xmlparser.GetInputContext()
+
+   Returns the input data that generated the current event as a string. The data is
+   in the encoding of the entity which contains the text. When called while an
+   event handler is not active, the return value is ``None``.
+
+   .. versionadded:: 2.1
+
+
+.. method:: xmlparser.ExternalEntityParserCreate(context[, encoding])
+
+   Create a "child" parser which can be used to parse an external parsed entity
+   referred to by content parsed by the parent parser.  The *context* parameter
+   should be the string passed to the :meth:`ExternalEntityRefHandler` handler
+   function, described below. The child parser is created with the
+   :attr:`ordered_attributes` and :attr:`specified_attributes` set to the values of
+   this parser.
+
+
+.. method:: xmlparser.UseForeignDTD([flag])
+
+   Calling this with a true value for *flag* (the default) will cause Expat to call
+   the :attr:`ExternalEntityRefHandler` with :const:`None` for all arguments to
+   allow an alternate DTD to be loaded.  If the document does not contain a
+   document type declaration, the :attr:`ExternalEntityRefHandler` will still be
+   called, but the :attr:`StartDoctypeDeclHandler` and
+   :attr:`EndDoctypeDeclHandler` will not be called.
+
+   Passing a false value for *flag* will cancel a previous call that passed a true
+   value, but otherwise has no effect.
+
+   This method can only be called before the :meth:`Parse` or :meth:`ParseFile`
+   methods are called; calling it after either of those have been called causes
+   :exc:`ExpatError` to be raised with the :attr:`code` attribute set to
+   :const:`errors.XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING`.
+
+   .. versionadded:: 2.3
+
+:class:`xmlparser` objects have the following attributes:
+
+
+.. attribute:: xmlparser.buffer_size
+
+   The size of the buffer used when :attr:`buffer_text` is true.  This value cannot
+   be changed at this time.
+
+   .. versionadded:: 2.3
+
+
+.. attribute:: xmlparser.buffer_text
+
+   Setting this to true causes the :class:`xmlparser` object to buffer textual
+   content returned by Expat to avoid multiple calls to the
+   :meth:`CharacterDataHandler` callback whenever possible.  This can improve
+   performance substantially since Expat normally breaks character data into chunks
+   at every line ending.  This attribute is false by default, and may be changed at
+   any time.
+
+   .. versionadded:: 2.3
+
+
+.. attribute:: xmlparser.buffer_used
+
+   If :attr:`buffer_text` is enabled, the number of bytes stored in the buffer.
+   These bytes represent UTF-8 encoded text.  This attribute has no meaningful
+   interpretation when :attr:`buffer_text` is false.
+
+   .. versionadded:: 2.3
+
+
+.. attribute:: xmlparser.ordered_attributes
+
+   Setting this attribute to a non-zero integer causes the attributes to be
+   reported as a list rather than a dictionary.  The attributes are presented in
+   the order found in the document text.  For each attribute, two list entries are
+   presented: the attribute name and the attribute value.  (Older versions of this
+   module also used this format.)  By default, this attribute is false; it may be
+   changed at any time.
+
+   .. versionadded:: 2.1
+
+
+.. attribute:: xmlparser.specified_attributes
+
+   If set to a non-zero integer, the parser will report only those attributes which
+   were specified in the document instance and not those which were derived from
+   attribute declarations.  Applications which set this need to be especially
+   careful to use what additional information is available from the declarations as
+   needed to comply with the standards for the behavior of XML processors.  By
+   default, this attribute is false; it may be changed at any time.
+
+   .. versionadded:: 2.1
+
+The following attributes contain values relating to the most recent error
+encountered by an :class:`xmlparser` object, and will only have correct values
+once a call to :meth:`Parse` or :meth:`ParseFile` has raised a
+:exc:`xml.parsers.expat.ExpatError` exception.
+
+
+.. attribute:: xmlparser.ErrorByteIndex
+
+   Byte index at which an error occurred.
+
+
+.. attribute:: xmlparser.ErrorCode
+
+   Numeric code specifying the problem.  This value can be passed to the
+   :func:`ErrorString` function, or compared to one of the constants defined in the
+   ``errors`` object.
+
+
+.. attribute:: xmlparser.ErrorColumnNumber
+
+   Column number at which an error occurred.
+
+
+.. attribute:: xmlparser.ErrorLineNumber
+
+   Line number at which an error occurred.
+
+The following attributes contain values relating to the current parse location
+in an :class:`xmlparser` object.  During a callback reporting a parse event they
+indicate the location of the first of the sequence of characters that generated
+the event.  When called outside of a callback, the position indicated will be
+just past the last parse event (regardless of whether there was an associated
+callback).
+
+.. versionadded:: 2.4
+
+
+.. attribute:: xmlparser.CurrentByteIndex
+
+   Current byte index in the parser input.
+
+
+.. attribute:: xmlparser.CurrentColumnNumber
+
+   Current column number in the parser input.
+
+
+.. attribute:: xmlparser.CurrentLineNumber
+
+   Current line number in the parser input.
+
+Here is the list of handlers that can be set.  To set a handler on an
+:class:`xmlparser` object *o*, use ``o.handlername = func``.  *handlername* must
+be taken from the following list, and *func* must be a callable object accepting
+the correct number of arguments.  The arguments are all strings, unless
+otherwise stated.
+
+
+.. method:: xmlparser.XmlDeclHandler(version, encoding, standalone)
+
+   Called when the XML declaration is parsed.  The XML declaration is the
+   (optional) declaration of the applicable version of the XML recommendation, the
+   encoding of the document text, and an optional "standalone" declaration.
+   *version* and *encoding* will be strings, and *standalone* will be ``1`` if the
+   document is declared standalone, ``0`` if it is declared not to be standalone,
+   or ``-1`` if the standalone clause was omitted. This is only available with
+   Expat version 1.95.0 or newer.
+
+   .. versionadded:: 2.1
+
+
+.. method:: xmlparser.StartDoctypeDeclHandler(doctypeName, systemId, publicId, has_internal_subset)
+
+   Called when Expat begins parsing the document type declaration (````'.
+
+
+.. method:: xmlparser.StartCdataSectionHandler()
+
+   Called at the start of a CDATA section.  This and :attr:`EndCdataSectionHandler`
+   are needed to be able to identify the syntactical start and end for CDATA
+   sections.
+
+
+.. method:: xmlparser.EndCdataSectionHandler()
+
+   Called at the end of a CDATA section.
+
+
+.. method:: xmlparser.DefaultHandler(data)
+
+   Called for any characters in the XML document for which no applicable handler
+   has been specified.  This means characters that are part of a construct which
+   could be reported, but for which no handler has been supplied.
+
+
+.. method:: xmlparser.DefaultHandlerExpand(data)
+
+   This is the same as the :func:`DefaultHandler`,  but doesn't inhibit expansion
+   of internal entities. The entity reference will not be passed to the default
+   handler.
+
+
+.. method:: xmlparser.NotStandaloneHandler()
+
+   Called if the XML document hasn't been declared as being a standalone document.
+   This happens when there is an external subset or a reference to a parameter
+   entity, but the XML declaration does not set standalone to ``yes`` in an XML
+   declaration.  If this handler returns ``0``, then the parser will throw an
+   :const:`XML_ERROR_NOT_STANDALONE` error.  If this handler is not set, no
+   exception is raised by the parser for this condition.
+
+
+.. method:: xmlparser.ExternalEntityRefHandler(context, base, systemId, publicId)
+
+   Called for references to external entities.  *base* is the current base, as set
+   by a previous call to :meth:`SetBase`.  The public and system identifiers,
+   *systemId* and *publicId*, are strings if given; if the public identifier is not
+   given, *publicId* will be ``None``.  The *context* value is opaque and should
+   only be used as described below.
+
+   For external entities to be parsed, this handler must be implemented. It is
+   responsible for creating the sub-parser using
+   ``ExternalEntityParserCreate(context)``, initializing it with the appropriate
+   callbacks, and parsing the entity.  This handler should return an integer; if it
+   returns ``0``, the parser will throw an
+   :const:`XML_ERROR_EXTERNAL_ENTITY_HANDLING` error, otherwise parsing will
+   continue.
+
+   If this handler is not provided, external entities are reported by the
+   :attr:`DefaultHandler` callback, if provided.
+
+
+.. _expaterror-objects:
+
+ExpatError Exceptions
+---------------------
+
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+:exc:`ExpatError` exceptions have a number of interesting attributes:
+
+
+.. attribute:: ExpatError.code
+
+   Expat's internal error number for the specific error.  This will match one of
+   the constants defined in the ``errors`` object from this module.
+
+   .. versionadded:: 2.1
+
+
+.. attribute:: ExpatError.lineno
+
+   Line number on which the error was detected.  The first line is numbered ``1``.
+
+   .. versionadded:: 2.1
+
+
+.. attribute:: ExpatError.offset
+
+   Character offset into the line where the error occurred.  The first column is
+   numbered ``0``.
+
+   .. versionadded:: 2.1
+
+
+.. _expat-example:
+
+Example
+-------
+
+The following program defines three handlers that just print out their
+arguments. ::
+
+   import xml.parsers.expat
+
+   # 3 handler functions
+   def start_element(name, attrs):
+       print 'Start element:', name, attrs
+   def end_element(name):
+       print 'End element:', name
+   def char_data(data):
+       print 'Character data:', repr(data)
+
+   p = xml.parsers.expat.ParserCreate()
+
+   p.StartElementHandler = start_element
+   p.EndElementHandler = end_element
+   p.CharacterDataHandler = char_data
+
+   p.Parse("""
+   Text goes here
+   More text
+   """, 1)
+
+The output from this program is::
+
+   Start element: parent {'id': 'top'}
+   Start element: child1 {'name': 'paul'}
+   Character data: 'Text goes here'
+   End element: child1
+   Character data: '\n'
+   Start element: child2 {'name': 'fred'}
+   Character data: 'More text'
+   End element: child2
+   Character data: '\n'
+   End element: parent
+
+
+.. _expat-content-models:
+
+Content Model Descriptions
+--------------------------
+
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+Content modules are described using nested tuples.  Each tuple contains four
+values: the type, the quantifier, the name, and a tuple of children.  Children
+are simply additional content module descriptions.
+
+The values of the first two fields are constants defined in the ``model`` object
+of the :mod:`xml.parsers.expat` module.  These constants can be collected in two
+groups: the model type group and the quantifier group.
+
+The constants in the model type group are:
+
+
+.. data:: XML_CTYPE_ANY
+   :noindex:
+
+   The element named by the model name was declared to have a content model of
+   ``ANY``.
+
+
+.. data:: XML_CTYPE_CHOICE
+   :noindex:
+
+   The named element allows a choice from a number of options; this is used for
+   content models such as ``(A | B | C)``.
+
+
+.. data:: XML_CTYPE_EMPTY
+   :noindex:
+
+   Elements which are declared to be ``EMPTY`` have this model type.
+
+
+.. data:: XML_CTYPE_MIXED
+   :noindex:
+
+
+.. data:: XML_CTYPE_NAME
+   :noindex:
+
+
+.. data:: XML_CTYPE_SEQ
+   :noindex:
+
+   Models which represent a series of models which follow one after the other are
+   indicated with this model type.  This is used for models such as ``(A, B, C)``.
+
+The constants in the quantifier group are:
+
+
+.. data:: XML_CQUANT_NONE
+   :noindex:
+
+   No modifier is given, so it can appear exactly once, as for ``A``.
+
+
+.. data:: XML_CQUANT_OPT
+   :noindex:
+
+   The model is optional: it can appear once or not at all, as for ``A?``.
+
+
+.. data:: XML_CQUANT_PLUS
+   :noindex:
+
+   The model must occur one or more times (like ``A+``).
+
+
+.. data:: XML_CQUANT_REP
+   :noindex:
+
+   The model must occur zero or more times, as for ``A*``.
+
+
+.. _expat-errors:
+
+Expat error constants
+---------------------
+
+The following constants are provided in the ``errors`` object of the
+:mod:`xml.parsers.expat` module.  These constants are useful in interpreting
+some of the attributes of the :exc:`ExpatError` exception objects raised when an
+error has occurred.
+
+The ``errors`` object has the following attributes:
+
+
+.. data:: XML_ERROR_ASYNC_ENTITY
+   :noindex:
+
+
+.. data:: XML_ERROR_ATTRIBUTE_EXTERNAL_ENTITY_REF
+   :noindex:
+
+   An entity reference in an attribute value referred to an external entity instead
+   of an internal entity.
+
+
+.. data:: XML_ERROR_BAD_CHAR_REF
+   :noindex:
+
+   A character reference referred to a character which is illegal in XML (for
+   example, character ``0``, or '``�``').
+
+
+.. data:: XML_ERROR_BINARY_ENTITY_REF
+   :noindex:
+
+   An entity reference referred to an entity which was declared with a notation, so
+   cannot be parsed.
+
+
+.. data:: XML_ERROR_DUPLICATE_ATTRIBUTE
+   :noindex:
+
+   An attribute was used more than once in a start tag.
+
+
+.. data:: XML_ERROR_INCORRECT_ENCODING
+   :noindex:
+
+
+.. data:: XML_ERROR_INVALID_TOKEN
+   :noindex:
+
+   Raised when an input byte could not properly be assigned to a character; for
+   example, a NUL byte (value ``0``) in a UTF-8 input stream.
+
+
+.. data:: XML_ERROR_JUNK_AFTER_DOC_ELEMENT
+   :noindex:
+
+   Something other than whitespace occurred after the document element.
+
+
+.. data:: XML_ERROR_MISPLACED_XML_PI
+   :noindex:
+
+   An XML declaration was found somewhere other than the start of the input data.
+
+
+.. data:: XML_ERROR_NO_ELEMENTS
+   :noindex:
+
+   The document contains no elements (XML requires all documents to contain exactly
+   one top-level element)..
+
+
+.. data:: XML_ERROR_NO_MEMORY
+   :noindex:
+
+   Expat was not able to allocate memory internally.
+
+
+.. data:: XML_ERROR_PARAM_ENTITY_REF
+   :noindex:
+
+   A parameter entity reference was found where it was not allowed.
+
+
+.. data:: XML_ERROR_PARTIAL_CHAR
+   :noindex:
+
+   An incomplete character was found in the input.
+
+
+.. data:: XML_ERROR_RECURSIVE_ENTITY_REF
+   :noindex:
+
+   An entity reference contained another reference to the same entity; possibly via
+   a different name, and possibly indirectly.
+
+
+.. data:: XML_ERROR_SYNTAX
+   :noindex:
+
+   Some unspecified syntax error was encountered.
+
+
+.. data:: XML_ERROR_TAG_MISMATCH
+   :noindex:
+
+   An end tag did not match the innermost open start tag.
+
+
+.. data:: XML_ERROR_UNCLOSED_TOKEN
+   :noindex:
+
+   Some token (such as a start tag) was not closed before the end of the stream or
+   the next token was encountered.
+
+
+.. data:: XML_ERROR_UNDEFINED_ENTITY
+   :noindex:
+
+   A reference was made to a entity which was not defined.
+
+
+.. data:: XML_ERROR_UNKNOWN_ENCODING
+   :noindex:
+
+   The document encoding is not supported by Expat.
+
+
+.. data:: XML_ERROR_UNCLOSED_CDATA_SECTION
+   :noindex:
+
+   A CDATA marked section was not closed.
+
+
+.. data:: XML_ERROR_EXTERNAL_ENTITY_HANDLING
+   :noindex:
+
+
+.. data:: XML_ERROR_NOT_STANDALONE
+   :noindex:
+
+   The parser determined that the document was not "standalone" though it declared
+   itself to be in the XML declaration, and the :attr:`NotStandaloneHandler` was
+   set and returned ``0``.
+
+
+.. data:: XML_ERROR_UNEXPECTED_STATE
+   :noindex:
+
+
+.. data:: XML_ERROR_ENTITY_DECLARED_IN_PE
+   :noindex:
+
+
+.. data:: XML_ERROR_FEATURE_REQUIRES_XML_DTD
+   :noindex:
+
+   An operation was requested that requires DTD support to be compiled in, but
+   Expat was configured without DTD support.  This should never be reported by a
+   standard build of the :mod:`xml.parsers.expat` module.
+
+
+.. data:: XML_ERROR_CANT_CHANGE_FEATURE_ONCE_PARSING
+   :noindex:
+
+   A behavioral change was requested after parsing started that can only be changed
+   before parsing has started.  This is (currently) only raised by
+   :meth:`UseForeignDTD`.
+
+
+.. data:: XML_ERROR_UNBOUND_PREFIX
+   :noindex:
+
+   An undeclared prefix was found when namespace processing was enabled.
+
+
+.. data:: XML_ERROR_UNDECLARING_PREFIX
+   :noindex:
+
+   The document attempted to remove the namespace declaration associated with a
+   prefix.
+
+
+.. data:: XML_ERROR_INCOMPLETE_PE
+   :noindex:
+
+   A parameter entity contained incomplete markup.
+
+
+.. data:: XML_ERROR_XML_DECL
+   :noindex:
+
+   The document contained no document element at all.
+
+
+.. data:: XML_ERROR_TEXT_DECL
+   :noindex:
+
+   There was an error parsing a text declaration in an external entity.
+
+
+.. data:: XML_ERROR_PUBLICID
+   :noindex:
+
+   Characters were found in the public id that are not allowed.
+
+
+.. data:: XML_ERROR_SUSPENDED
+   :noindex:
+
+   The requested operation was made on a suspended parser, but isn't allowed.  This
+   includes attempts to provide additional input or to stop the parser.
+
+
+.. data:: XML_ERROR_NOT_SUSPENDED
+   :noindex:
+
+   An attempt to resume the parser was made when the parser had not been suspended.
+
+
+.. data:: XML_ERROR_ABORTED
+   :noindex:
+
+   This should not be reported to Python applications.
+
+
+.. data:: XML_ERROR_FINISHED
+   :noindex:
+
+   The requested operation was made on a parser which was finished parsing input,
+   but isn't allowed.  This includes attempts to provide additional input or to
+   stop the parser.
+
+
+.. data:: XML_ERROR_SUSPEND_PE
+   :noindex:
+
diff --git a/Doc/library/python.rst b/Doc/library/python.rst
new file mode 100644
index 0000000..3b58eee
--- /dev/null
+++ b/Doc/library/python.rst
@@ -0,0 +1,27 @@
+
+.. _python:
+
+***********************
+Python Runtime Services
+***********************
+
+The modules described in this chapter provide a wide range of services related
+to the Python interpreter and its interaction with its environment.  Here's an
+overview:
+
+
+.. toctree::
+
+   sys.rst
+   __builtin__.rst
+   __main__.rst
+   warnings.rst
+   contextlib.rst
+   atexit.rst
+   traceback.rst
+   __future__.rst
+   gc.rst
+   inspect.rst
+   site.rst
+   user.rst
+   fpectl.rst
diff --git a/Doc/library/queue.rst b/Doc/library/queue.rst
new file mode 100644
index 0000000..c7b65fd
--- /dev/null
+++ b/Doc/library/queue.rst
@@ -0,0 +1,152 @@
+
+:mod:`Queue` --- A synchronized queue class
+===========================================
+
+.. module:: Queue
+   :synopsis: A synchronized queue class.
+
+
+The :mod:`Queue` module implements a multi-producer, multi-consumer FIFO queue.
+It is especially useful in threads programming when information must be
+exchanged safely between multiple threads.  The :class:`Queue` class in this
+module implements all the required locking semantics.  It depends on the
+availability of thread support in Python.
+
+The :mod:`Queue` module defines the following class and exception:
+
+
+.. class:: Queue(maxsize)
+
+   Constructor for the class.  *maxsize* is an integer that sets the upperbound
+   limit on the number of items that can be placed in the queue.  Insertion will
+   block once this size has been reached, until queue items are consumed.  If
+   *maxsize* is less than or equal to zero, the queue size is infinite.
+
+
+.. exception:: Empty
+
+   Exception raised when non-blocking :meth:`get` (or :meth:`get_nowait`) is called
+   on a :class:`Queue` object which is empty.
+
+
+.. exception:: Full
+
+   Exception raised when non-blocking :meth:`put` (or :meth:`put_nowait`) is called
+   on a :class:`Queue` object which is full.
+
+
+.. _queueobjects:
+
+Queue Objects
+-------------
+
+Class :class:`Queue` implements queue objects and has the methods described
+below.  This class can be derived from in order to implement other queue
+organizations (e.g. stack) but the inheritable interface is not described here.
+See the source code for details.  The public methods are:
+
+
+.. method:: Queue.qsize()
+
+   Return the approximate size of the queue.  Because of multithreading semantics,
+   this number is not reliable.
+
+
+.. method:: Queue.empty()
+
+   Return ``True`` if the queue is empty, ``False`` otherwise. Because of
+   multithreading semantics, this is not reliable.
+
+
+.. method:: Queue.full()
+
+   Return ``True`` if the queue is full, ``False`` otherwise. Because of
+   multithreading semantics, this is not reliable.
+
+
+.. method:: Queue.put(item[, block[, timeout]])
+
+   Put *item* into the queue. If optional args *block* is true and *timeout* is
+   None (the default), block if necessary until a free slot is available. If
+   *timeout* is a positive number, it blocks at most *timeout* seconds and raises
+   the :exc:`Full` exception if no free slot was available within that time.
+   Otherwise (*block* is false), put an item on the queue if a free slot is
+   immediately available, else raise the :exc:`Full` exception (*timeout* is
+   ignored in that case).
+
+   .. versionadded:: 2.3
+      The *timeout* parameter.
+
+
+.. method:: Queue.put_nowait(item)
+
+   Equivalent to ``put(item, False)``.
+
+
+.. method:: Queue.get([block[, timeout]])
+
+   Remove and return an item from the queue. If optional args *block* is true and
+   *timeout* is None (the default), block if necessary until an item is available.
+   If *timeout* is a positive number, it blocks at most *timeout* seconds and
+   raises the :exc:`Empty` exception if no item was available within that time.
+   Otherwise (*block* is false), return an item if one is immediately available,
+   else raise the :exc:`Empty` exception (*timeout* is ignored in that case).
+
+   .. versionadded:: 2.3
+      The *timeout* parameter.
+
+
+.. method:: Queue.get_nowait()
+
+   Equivalent to ``get(False)``.
+
+Two methods are offered to support tracking whether enqueued tasks have been
+fully processed by daemon consumer threads.
+
+
+.. method:: Queue.task_done()
+
+   Indicate that a formerly enqueued task is complete.  Used by queue consumer
+   threads.  For each :meth:`get` used to fetch a task, a subsequent call to
+   :meth:`task_done` tells the queue that the processing on the task is complete.
+
+   If a :meth:`join` is currently blocking, it will resume when all items have been
+   processed (meaning that a :meth:`task_done` call was received for every item
+   that had been :meth:`put` into the queue).
+
+   Raises a :exc:`ValueError` if called more times than there were items placed in
+   the queue.
+
+   .. versionadded:: 2.5
+
+
+.. method:: Queue.join()
+
+   Blocks until all items in the queue have been gotten and processed.
+
+   The count of unfinished tasks goes up whenever an item is added to the queue.
+   The count goes down whenever a consumer thread calls :meth:`task_done` to
+   indicate that the item was retrieved and all work on it is complete. When the
+   count of unfinished tasks drops to zero, join() unblocks.
+
+   .. versionadded:: 2.5
+
+Example of how to wait for enqueued tasks to be completed::
+
+   def worker(): 
+       while True: 
+           item = q.get() 
+           do_work(item) 
+           q.task_done() 
+
+   q = Queue() 
+   for i in range(num_worker_threads): 
+        t = Thread(target=worker)
+        t.setDaemon(True)
+        t.start() 
+
+   for item in source():
+       q.put(item) 
+
+   q.join()       # block until all tasks are done
+
diff --git a/Doc/library/quopri.rst b/Doc/library/quopri.rst
new file mode 100644
index 0000000..8f525ef
--- /dev/null
+++ b/Doc/library/quopri.rst
@@ -0,0 +1,61 @@
+
+:mod:`quopri` --- Encode and decode MIME quoted-printable data
+==============================================================
+
+.. module:: quopri
+   :synopsis: Encode and decode files using the MIME quoted-printable encoding.
+
+
+.. index::
+   pair: quoted-printable; encoding
+   single: MIME; quoted-printable encoding
+
+This module performs quoted-printable transport encoding and decoding, as
+defined in :rfc:`1521`: "MIME (Multipurpose Internet Mail Extensions) Part One:
+Mechanisms for Specifying and Describing the Format of Internet Message Bodies".
+The quoted-printable encoding is designed for data where there are relatively
+few nonprintable characters; the base64 encoding scheme available via the
+:mod:`base64` module is more compact if there are many such characters, as when
+sending a graphics file.
+
+
+.. function:: decode(input, output[,header])
+
+   Decode the contents of the *input* file and write the resulting decoded binary
+   data to the *output* file. *input* and *output* must either be file objects or
+   objects that mimic the file object interface. *input* will be read until
+   ``input.readline()`` returns an empty string. If the optional argument *header*
+   is present and true, underscore will be decoded as space. This is used to decode
+   "Q"-encoded headers as described in :rfc:`1522`: "MIME (Multipurpose Internet
+   Mail Extensions) Part Two: Message Header Extensions for Non-ASCII Text".
+
+
+.. function:: encode(input, output, quotetabs)
+
+   Encode the contents of the *input* file and write the resulting quoted-printable
+   data to the *output* file. *input* and *output* must either be file objects or
+   objects that mimic the file object interface. *input* will be read until
+   ``input.readline()`` returns an empty string. *quotetabs* is a flag which
+   controls whether to encode embedded spaces and tabs; when true it encodes such
+   embedded whitespace, and when false it leaves them unencoded.  Note that spaces
+   and tabs appearing at the end of lines are always encoded, as per :rfc:`1521`.
+
+
+.. function:: decodestring(s[,header])
+
+   Like :func:`decode`, except that it accepts a source string and returns the
+   corresponding decoded string.
+
+
+.. function:: encodestring(s[, quotetabs])
+
+   Like :func:`encode`, except that it accepts a source string and returns the
+   corresponding encoded string.  *quotetabs* is optional (defaulting to 0), and is
+   passed straight through to :func:`encode`.
+
+
+.. seealso::
+
+   Module :mod:`base64`
+      Encode and decode MIME base64 data
+
diff --git a/Doc/library/random.rst b/Doc/library/random.rst
new file mode 100644
index 0000000..c5d289c
--- /dev/null
+++ b/Doc/library/random.rst
@@ -0,0 +1,315 @@
+
+:mod:`random` --- Generate pseudo-random numbers
+================================================
+
+.. module:: random
+   :synopsis: Generate pseudo-random numbers with various common distributions.
+
+
+This module implements pseudo-random number generators for various
+distributions.
+
+For integers, uniform selection from a range. For sequences, uniform selection
+of a random element, a function to generate a random permutation of a list
+in-place, and a function for random sampling without replacement.
+
+On the real line, there are functions to compute uniform, normal (Gaussian),
+lognormal, negative exponential, gamma, and beta distributions. For generating
+distributions of angles, the von Mises distribution is available.
+
+Almost all module functions depend on the basic function :func:`random`, which
+generates a random float uniformly in the semi-open range [0.0, 1.0).  Python
+uses the Mersenne Twister as the core generator.  It produces 53-bit precision
+floats and has a period of 2\*\*19937-1.  The underlying implementation in C is
+both fast and threadsafe.  The Mersenne Twister is one of the most extensively
+tested random number generators in existence.  However, being completely
+deterministic, it is not suitable for all purposes, and is completely unsuitable
+for cryptographic purposes.
+
+The functions supplied by this module are actually bound methods of a hidden
+instance of the :class:`random.Random` class.  You can instantiate your own
+instances of :class:`Random` to get generators that don't share state.  This is
+especially useful for multi-threaded programs, creating a different instance of
+:class:`Random` for each thread, and using the :meth:`jumpahead` method to make
+it likely that the generated sequences seen by each thread don't overlap.
+
+Class :class:`Random` can also be subclassed if you want to use a different
+basic generator of your own devising: in that case, override the :meth:`random`,
+:meth:`seed`, :meth:`getstate`, :meth:`setstate` and :meth:`jumpahead` methods.
+Optionally, a new generator can supply a :meth:`getrandombits` method --- this
+allows :meth:`randrange` to produce selections over an arbitrarily large range.
+
+.. versionadded:: 2.4
+   the :meth:`getrandombits` method.
+
+As an example of subclassing, the :mod:`random` module provides the
+:class:`WichmannHill` class that implements an alternative generator in pure
+Python.  The class provides a backward compatible way to reproduce results from
+earlier versions of Python, which used the Wichmann-Hill algorithm as the core
+generator.  Note that this Wichmann-Hill generator can no longer be recommended:
+its period is too short by contemporary standards, and the sequence generated is
+known to fail some stringent randomness tests.  See the references below for a
+recent variant that repairs these flaws.
+
+.. versionchanged:: 2.3
+   Substituted MersenneTwister for Wichmann-Hill.
+
+Bookkeeping functions:
+
+
+.. function:: seed([x])
+
+   Initialize the basic random number generator. Optional argument *x* can be any
+   hashable object. If *x* is omitted or ``None``, current system time is used;
+   current system time is also used to initialize the generator when the module is
+   first imported.  If randomness sources are provided by the operating system,
+   they are used instead of the system time (see the :func:`os.urandom` function
+   for details on availability).
+
+   .. versionchanged:: 2.4
+      formerly, operating system resources were not used.
+
+   If *x* is not ``None`` or an int or long, ``hash(x)`` is used instead. If *x* is
+   an int or long, *x* is used directly.
+
+
+.. function:: getstate()
+
+   Return an object capturing the current internal state of the generator.  This
+   object can be passed to :func:`setstate` to restore the state.
+
+   .. versionadded:: 2.1
+
+
+.. function:: setstate(state)
+
+   *state* should have been obtained from a previous call to :func:`getstate`, and
+   :func:`setstate` restores the internal state of the generator to what it was at
+   the time :func:`setstate` was called.
+
+   .. versionadded:: 2.1
+
+
+.. function:: jumpahead(n)
+
+   Change the internal state to one different from and likely far away from the
+   current state.  *n* is a non-negative integer which is used to scramble the
+   current state vector.  This is most useful in multi-threaded programs, in
+   conjuction with multiple instances of the :class:`Random` class:
+   :meth:`setstate` or :meth:`seed` can be used to force all instances into the
+   same internal state, and then :meth:`jumpahead` can be used to force the
+   instances' states far apart.
+
+   .. versionadded:: 2.1
+
+   .. versionchanged:: 2.3
+      Instead of jumping to a specific state, *n* steps ahead, ``jumpahead(n)``
+      jumps to another state likely to be separated by many steps.
+
+
+.. function:: getrandbits(k)
+
+   Returns a python :class:`long` int with *k* random bits. This method is supplied
+   with the MersenneTwister generator and some other generators may also provide it
+   as an optional part of the API. When available, :meth:`getrandbits` enables
+   :meth:`randrange` to handle arbitrarily large ranges.
+
+   .. versionadded:: 2.4
+
+Functions for integers:
+
+
+.. function:: randrange([start,] stop[, step])
+
+   Return a randomly selected element from ``range(start, stop, step)``.  This is
+   equivalent to ``choice(range(start, stop, step))``, but doesn't actually build a
+   range object.
+
+   .. versionadded:: 1.5.2
+
+
+.. function:: randint(a, b)
+
+   Return a random integer *N* such that ``a <= N <= b``.
+
+Functions for sequences:
+
+
+.. function:: choice(seq)
+
+   Return a random element from the non-empty sequence *seq*. If *seq* is empty,
+   raises :exc:`IndexError`.
+
+
+.. function:: shuffle(x[, random])
+
+   Shuffle the sequence *x* in place. The optional argument *random* is a
+   0-argument function returning a random float in [0.0, 1.0); by default, this is
+   the function :func:`random`.
+
+   Note that for even rather small ``len(x)``, the total number of permutations of
+   *x* is larger than the period of most random number generators; this implies
+   that most permutations of a long sequence can never be generated.
+
+
+.. function:: sample(population, k)
+
+   Return a *k* length list of unique elements chosen from the population sequence.
+   Used for random sampling without replacement.
+
+   .. versionadded:: 2.3
+
+   Returns a new list containing elements from the population while leaving the
+   original population unchanged.  The resulting list is in selection order so that
+   all sub-slices will also be valid random samples.  This allows raffle winners
+   (the sample) to be partitioned into grand prize and second place winners (the
+   subslices).
+
+   Members of the population need not be hashable or unique.  If the population
+   contains repeats, then each occurrence is a possible selection in the sample.
+
+   To choose a sample from a range of integers, use an :func:`range` object as an
+   argument.  This is especially fast and space efficient for sampling from a large
+   population:  ``sample(range(10000000), 60)``.
+
+The following functions generate specific real-valued distributions. Function
+parameters are named after the corresponding variables in the distribution's
+equation, as used in common mathematical practice; most of these equations can
+be found in any statistics text.
+
+
+.. function:: random()
+
+   Return the next random floating point number in the range [0.0, 1.0).
+
+
+.. function:: uniform(a, b)
+
+   Return a random floating point number *N* such that ``a <= N < b``.
+
+
+.. function:: betavariate(alpha, beta)
+
+   Beta distribution.  Conditions on the parameters are ``alpha > 0`` and ``beta >
+   0``. Returned values range between 0 and 1.
+
+
+.. function:: expovariate(lambd)
+
+   Exponential distribution.  *lambd* is 1.0 divided by the desired mean.  (The
+   parameter would be called "lambda", but that is a reserved word in Python.)
+   Returned values range from 0 to positive infinity.
+
+
+.. function:: gammavariate(alpha, beta)
+
+   Gamma distribution.  (*Not* the gamma function!)  Conditions on the parameters
+   are ``alpha > 0`` and ``beta > 0``.
+
+
+.. function:: gauss(mu, sigma)
+
+   Gaussian distribution.  *mu* is the mean, and *sigma* is the standard deviation.
+   This is slightly faster than the :func:`normalvariate` function defined below.
+
+
+.. function:: lognormvariate(mu, sigma)
+
+   Log normal distribution.  If you take the natural logarithm of this
+   distribution, you'll get a normal distribution with mean *mu* and standard
+   deviation *sigma*.  *mu* can have any value, and *sigma* must be greater than
+   zero.
+
+
+.. function:: normalvariate(mu, sigma)
+
+   Normal distribution.  *mu* is the mean, and *sigma* is the standard deviation.
+
+
+.. function:: vonmisesvariate(mu, kappa)
+
+   *mu* is the mean angle, expressed in radians between 0 and 2\*\ *pi*, and *kappa*
+   is the concentration parameter, which must be greater than or equal to zero.  If
+   *kappa* is equal to zero, this distribution reduces to a uniform random angle
+   over the range 0 to 2\*\ *pi*.
+
+
+.. function:: paretovariate(alpha)
+
+   Pareto distribution.  *alpha* is the shape parameter.
+
+
+.. function:: weibullvariate(alpha, beta)
+
+   Weibull distribution.  *alpha* is the scale parameter and *beta* is the shape
+   parameter.
+
+
+Alternative Generators:
+
+.. class:: WichmannHill([seed])
+
+   Class that implements the Wichmann-Hill algorithm as the core generator. Has all
+   of the same methods as :class:`Random` plus the :meth:`whseed` method described
+   below.  Because this class is implemented in pure Python, it is not threadsafe
+   and may require locks between calls.  The period of the generator is
+   6,953,607,871,644 which is small enough to require care that two independent
+   random sequences do not overlap.
+
+
+.. function:: whseed([x])
+
+   This is obsolete, supplied for bit-level compatibility with versions of Python
+   prior to 2.1. See :func:`seed` for details.  :func:`whseed` does not guarantee
+   that distinct integer arguments yield distinct internal states, and can yield no
+   more than about 2\*\*24 distinct internal states in all.
+
+
+.. class:: SystemRandom([seed])
+
+   Class that uses the :func:`os.urandom` function for generating random numbers
+   from sources provided by the operating system. Not available on all systems.
+   Does not rely on software state and sequences are not reproducible. Accordingly,
+   the :meth:`seed` and :meth:`jumpahead` methods have no effect and are ignored.
+   The :meth:`getstate` and :meth:`setstate` methods raise
+   :exc:`NotImplementedError` if called.
+
+   .. versionadded:: 2.4
+
+Examples of basic usage::
+
+   >>> random.random()        # Random float x, 0.0 <= x < 1.0
+   0.37444887175646646
+   >>> random.uniform(1, 10)  # Random float x, 1.0 <= x < 10.0
+   1.1800146073117523
+   >>> random.randint(1, 10)  # Integer from 1 to 10, endpoints included
+   7
+   >>> random.randrange(0, 101, 2)  # Even integer from 0 to 100
+   26
+   >>> random.choice('abcdefghij')  # Choose a random element
+   'c'
+
+   >>> items = [1, 2, 3, 4, 5, 6, 7]
+   >>> random.shuffle(items)
+   >>> items
+   [7, 3, 2, 5, 6, 4, 1]
+
+   >>> random.sample([1, 2, 3, 4, 5],  3)  # Choose 3 elements
+   [4, 1, 5]
+
+
+
+.. seealso::
+
+   M. Matsumoto and T. Nishimura, "Mersenne Twister: A 623-dimensionally
+   equidistributed uniform pseudorandom number generator", ACM Transactions on
+   Modeling and Computer Simulation Vol. 8, No. 1, January pp.3-30 1998.
+
+   Wichmann, B. A. & Hill, I. D., "Algorithm AS 183: An efficient and portable
+   pseudo-random number generator", Applied Statistics 31 (1982) 188-190.
+
+   http://www.npl.co.uk/ssfm/download/abstracts.html#196
+      A modern variation of the Wichmann-Hill generator that greatly increases the
+      period, and passes now-standard statistical tests that the original generator
+      failed.
+
diff --git a/Doc/library/re.rst b/Doc/library/re.rst
new file mode 100644
index 0000000..027ff16
--- /dev/null
+++ b/Doc/library/re.rst
@@ -0,0 +1,921 @@
+
+:mod:`re` --- Regular expression operations
+===========================================
+
+.. module:: re
+   :synopsis: Regular expression operations.
+.. moduleauthor:: Fredrik Lundh 
+.. sectionauthor:: Andrew M. Kuchling 
+
+
+
+
+This module provides regular expression matching operations similar to
+those found in Perl. Both patterns and strings to be searched can be
+Unicode strings as well as 8-bit strings.  The :mod:`re` module is
+always available.
+
+Regular expressions use the backslash character (``'\'``) to indicate
+special forms or to allow special characters to be used without invoking
+their special meaning.  This collides with Python's usage of the same
+character for the same purpose in string literals; for example, to match
+a literal backslash, one might have to write ``'\\\\'`` as the pattern
+string, because the regular expression must be ``\\``, and each
+backslash must be expressed as ``\\`` inside a regular Python string
+literal.
+
+The solution is to use Python's raw string notation for regular expression
+patterns; backslashes are not handled in any special way in a string literal
+prefixed with ``'r'``.  So ``r"\n"`` is a two-character string containing
+``'\'`` and ``'n'``, while ``"\n"`` is a one-character string containing a
+newline. Usually patterns will be expressed in Python code using this raw string
+notation.
+
+.. seealso::
+
+   Mastering Regular Expressions
+      Book on regular expressions by Jeffrey Friedl, published by O'Reilly.  The
+      second  edition of the book no longer covers Python at all,  but the first
+      edition covered writing good regular expression patterns in great detail.
+
+
+.. _re-syntax:
+
+Regular Expression Syntax
+-------------------------
+
+A regular expression (or RE) specifies a set of strings that matches it; the
+functions in this module let you check if a particular string matches a given
+regular expression (or if a given regular expression matches a particular
+string, which comes down to the same thing).
+
+Regular expressions can be concatenated to form new regular expressions; if *A*
+and *B* are both regular expressions, then *AB* is also a regular expression.
+In general, if a string *p* matches *A* and another string *q* matches *B*, the
+string *pq* will match AB.  This holds unless *A* or *B* contain low precedence
+operations; boundary conditions between *A* and *B*; or have numbered group
+references.  Thus, complex expressions can easily be constructed from simpler
+primitive expressions like the ones described here.  For details of the theory
+and implementation of regular expressions, consult the Friedl book referenced
+above, or almost any textbook about compiler construction.
+
+A brief explanation of the format of regular expressions follows.  For further
+information and a gentler presentation, consult the Regular Expression HOWTO,
+accessible from http://www.python.org/doc/howto/.
+
+Regular expressions can contain both special and ordinary characters. Most
+ordinary characters, like ``'A'``, ``'a'``, or ``'0'``, are the simplest regular
+expressions; they simply match themselves.  You can concatenate ordinary
+characters, so ``last`` matches the string ``'last'``.  (In the rest of this
+section, we'll write RE's in ``this special style``, usually without quotes, and
+strings to be matched ``'in single quotes'``.)
+
+Some characters, like ``'|'`` or ``'('``, are special. Special
+characters either stand for classes of ordinary characters, or affect
+how the regular expressions around them are interpreted. Regular
+expression pattern strings may not contain null bytes, but can specify
+the null byte using the ``\number`` notation, e.g., ``'\x00'``.
+
+
+The special characters are:
+
+.. % 
+
+``'.'``
+   (Dot.)  In the default mode, this matches any character except a newline.  If
+   the :const:`DOTALL` flag has been specified, this matches any character
+   including a newline.
+
+``'^'``
+   (Caret.)  Matches the start of the string, and in :const:`MULTILINE` mode also
+   matches immediately after each newline.
+
+``'$'``
+   Matches the end of the string or just before the newline at the end of the
+   string, and in :const:`MULTILINE` mode also matches before a newline.  ``foo``
+   matches both 'foo' and 'foobar', while the regular expression ``foo$`` matches
+   only 'foo'.  More interestingly, searching for ``foo.$`` in ``'foo1\nfoo2\n'``
+   matches 'foo2' normally, but 'foo1' in :const:`MULTILINE` mode.
+
+``'*'``
+   Causes the resulting RE to match 0 or more repetitions of the preceding RE, as
+   many repetitions as are possible.  ``ab*`` will match 'a', 'ab', or 'a' followed
+   by any number of 'b's.
+
+``'+'``
+   Causes the resulting RE to match 1 or more repetitions of the preceding RE.
+   ``ab+`` will match 'a' followed by any non-zero number of 'b's; it will not
+   match just 'a'.
+
+``'?'``
+   Causes the resulting RE to match 0 or 1 repetitions of the preceding RE.
+   ``ab?`` will match either 'a' or 'ab'.
+
+``*?``, ``+?``, ``??``
+   The ``'*'``, ``'+'``, and ``'?'`` qualifiers are all :dfn:`greedy`; they match
+   as much text as possible.  Sometimes this behaviour isn't desired; if the RE
+   ``<.*>`` is matched against ``'
    title
    '``, it will match the entire
+   string, and not just ``'
    '``.  Adding ``'?'`` after the qualifier makes it
+   perform the match in :dfn:`non-greedy` or :dfn:`minimal` fashion; as *few*
+   characters as possible will be matched.  Using ``.*?`` in the previous
+   expression will match only ``'
    '``.
+
+``{m}``
+   Specifies that exactly *m* copies of the previous RE should be matched; fewer
+   matches cause the entire RE not to match.  For example, ``a{6}`` will match
+   exactly six ``'a'`` characters, but not five.
+
+``{m,n}``
+   Causes the resulting RE to match from *m* to *n* repetitions of the preceding
+   RE, attempting to match as many repetitions as possible.  For example,
+   ``a{3,5}`` will match from 3 to 5 ``'a'`` characters.  Omitting *m* specifies a
+   lower bound of zero,  and omitting *n* specifies an infinite upper bound.  As an
+   example, ``a{4,}b`` will match ``aaaab`` or a thousand ``'a'`` characters
+   followed by a ``b``, but not ``aaab``. The comma may not be omitted or the
+   modifier would be confused with the previously described form.
+
+``{m,n}?``
+   Causes the resulting RE to match from *m* to *n* repetitions of the preceding
+   RE, attempting to match as *few* repetitions as possible.  This is the
+   non-greedy version of the previous qualifier.  For example, on the
+   6-character string ``'aaaaaa'``, ``a{3,5}`` will match 5 ``'a'`` characters,
+   while ``a{3,5}?`` will only match 3 characters.
+
+``'\'``
+   Either escapes special characters (permitting you to match characters like
+   ``'*'``, ``'?'``, and so forth), or signals a special sequence; special
+   sequences are discussed below.
+
+   If you're not using a raw string to express the pattern, remember that Python
+   also uses the backslash as an escape sequence in string literals; if the escape
+   sequence isn't recognized by Python's parser, the backslash and subsequent
+   character are included in the resulting string.  However, if Python would
+   recognize the resulting sequence, the backslash should be repeated twice.  This
+   is complicated and hard to understand, so it's highly recommended that you use
+   raw strings for all but the simplest expressions.
+
+``[]``
+   Used to indicate a set of characters.  Characters can be listed individually, or
+   a range of characters can be indicated by giving two characters and separating
+   them by a ``'-'``.  Special characters are not active inside sets.  For example,
+   ``[akm$]`` will match any of the characters ``'a'``, ``'k'``,
+   ``'m'``, or ``'$'``; ``[a-z]`` will match any lowercase letter, and
+   ``[a-zA-Z0-9]`` matches any letter or digit.  Character classes such
+   as ``\w`` or ``\S`` (defined below) are also acceptable inside a
+   range, although the characters they match depends on whether :const:`LOCALE`
+   or  :const:`UNICODE` mode is in force.  If you want to include a
+   ``']'`` or a ``'-'`` inside a set, precede it with a backslash, or
+   place it as the first character.  The pattern ``[]]`` will match
+   ``']'``, for example.
+
+   You can match the characters not within a range by :dfn:`complementing` the set.
+   This is indicated by including a ``'^'`` as the first character of the set;
+   ``'^'`` elsewhere will simply match the ``'^'`` character.  For example,
+   ``[^5]`` will match any character except ``'5'``, and ``[^^]`` will match any
+   character except ``'^'``.
+
+``'|'``
+   ``A|B``, where A and B can be arbitrary REs, creates a regular expression that
+   will match either A or B.  An arbitrary number of REs can be separated by the
+   ``'|'`` in this way.  This can be used inside groups (see below) as well.  As
+   the target string is scanned, REs separated by ``'|'`` are tried from left to
+   right. When one pattern completely matches, that branch is accepted. This means
+   that once ``A`` matches, ``B`` will not be tested further, even if it would
+   produce a longer overall match.  In other words, the ``'|'`` operator is never
+   greedy.  To match a literal ``'|'``, use ``\|``, or enclose it inside a
+   character class, as in ``[|]``.
+
+``(...)``
+   Matches whatever regular expression is inside the parentheses, and indicates the
+   start and end of a group; the contents of a group can be retrieved after a match
+   has been performed, and can be matched later in the string with the ``\number``
+   special sequence, described below.  To match the literals ``'('`` or ``')'``,
+   use ``\(`` or ``\)``, or enclose them inside a character class: ``[(] [)]``.
+
+``(?...)``
+   This is an extension notation (a ``'?'`` following a ``'('`` is not meaningful
+   otherwise).  The first character after the ``'?'`` determines what the meaning
+   and further syntax of the construct is. Extensions usually do not create a new
+   group; ``(?P...)`` is the only exception to this rule. Following are the
+   currently supported extensions.
+
+``(?iLmsux)``
+   (One or more letters from the set ``'i'``, ``'L'``, ``'m'``, ``'s'``,
+   ``'u'``, ``'x'``.)  The group matches the empty string; the letters
+   set the corresponding flags: :const:`re.I` (ignore case),
+   :const:`re.L` (locale dependent), :const:`re.M` (multi-line),
+   :const:`re.S` (dot matches all), :const:`re.U` (Unicode dependent),
+   and :const:`re.X` (verbose), for the entire regular expression. (The
+   flags are described in :ref:`contents-of-module-re`.) This
+   is useful if you wish to include the flags as part of the regular
+   expression, instead of passing a *flag* argument to the
+   :func:`compile` function.
+
+   Note that the ``(?x)`` flag changes how the expression is parsed. It should be
+   used first in the expression string, or after one or more whitespace characters.
+   If there are non-whitespace characters before the flag, the results are
+   undefined.
+
+``(?:...)``
+   A non-grouping version of regular parentheses. Matches whatever regular
+   expression is inside the parentheses, but the substring matched by the group
+   *cannot* be retrieved after performing a match or referenced later in the
+   pattern.
+
+``(?P...)``
+   Similar to regular parentheses, but the substring matched by the group is
+   accessible via the symbolic group name *name*.  Group names must be valid Python
+   identifiers, and each group name must be defined only once within a regular
+   expression.  A symbolic group is also a numbered group, just as if the group
+   were not named.  So the group named 'id' in the example below can also be
+   referenced as the numbered group 1.
+
+   For example, if the pattern is ``(?P[a-zA-Z_]\w*)``, the group can be
+   referenced by its name in arguments to methods of match objects, such as
+   ``m.group('id')`` or ``m.end('id')``, and also by name in pattern text (for
+   example, ``(?P=id)``) and replacement text (such as ``\g``).
+
+``(?P=name)``
+   Matches whatever text was matched by the earlier group named *name*.
+
+``(?#...)``
+   A comment; the contents of the parentheses are simply ignored.
+
+``(?=...)``
+   Matches if ``...`` matches next, but doesn't consume any of the string.  This is
+   called a lookahead assertion.  For example, ``Isaac (?=Asimov)`` will match
+   ``'Isaac '`` only if it's followed by ``'Asimov'``.
+
+``(?!...)``
+   Matches if ``...`` doesn't match next.  This is a negative lookahead assertion.
+   For example, ``Isaac (?!Asimov)`` will match ``'Isaac '`` only if it's *not*
+   followed by ``'Asimov'``.
+
+``(?<=...)``
+   Matches if the current position in the string is preceded by a match for ``...``
+   that ends at the current position.  This is called a :dfn:`positive lookbehind
+   assertion`. ``(?<=abc)def`` will find a match in ``abcdef``, since the
+   lookbehind will back up 3 characters and check if the contained pattern matches.
+   The contained pattern must only match strings of some fixed length, meaning that
+   ``abc`` or ``a|b`` are allowed, but ``a*`` and ``a{3,4}`` are not.  Note that
+   patterns which start with positive lookbehind assertions will never match at the
+   beginning of the string being searched; you will most likely want to use the
+   :func:`search` function rather than the :func:`match` function::
+
+      >>> import re
+      >>> m = re.search('(?<=abc)def', 'abcdef')
+      >>> m.group(0)
+      'def'
+
+   This example looks for a word following a hyphen::
+
+      >>> m = re.search('(?<=-)\w+', 'spam-egg')
+      >>> m.group(0)
+      'egg'
+
+``(?)`` is a poor email
+   matching pattern, which will match with ``''`` as well as
+   ``'user@host.com'``, but not with ``'
+
+
+Python offers two different primitive operations based on regular expressions:
+match and search.  If you are accustomed to Perl's semantics, the search
+operation is what you're looking for.  See the :func:`search` function and
+corresponding method of compiled regular expression objects.
+
+Note that match may differ from search using a regular expression beginning with
+``'^'``: ``'^'`` matches only at the start of the string, or in
+:const:`MULTILINE` mode also immediately following a newline.  The "match"
+operation succeeds only if the pattern matches at the start of the string
+regardless of mode, or at the starting position given by the optional *pos*
+argument regardless of whether a newline precedes it.
+
+.. % Examples from Tim Peters:
+
+::
+
+   re.compile("a").match("ba", 1)           # succeeds
+   re.compile("^a").search("ba", 1)         # fails; 'a' not at start
+   re.compile("^a").search("\na", 1)        # fails; 'a' not at start
+   re.compile("^a", re.M).search("\na", 1)  # succeeds
+   re.compile("^a", re.M).search("ba", 1)   # fails; no preceding \n
+
+
+.. _contents-of-module-re:
+
+Module Contents
+---------------
+
+The module defines several functions, constants, and an exception. Some of the
+functions are simplified versions of the full featured methods for compiled
+regular expressions.  Most non-trivial applications always use the compiled
+form.
+
+
+.. function:: compile(pattern[, flags])
+
+   Compile a regular expression pattern into a regular expression object, which can
+   be used for matching using its :func:`match` and :func:`search` methods,
+   described below.
+
+   The expression's behaviour can be modified by specifying a *flags* value.
+   Values can be any of the following variables, combined using bitwise OR (the
+   ``|`` operator).
+
+   The sequence ::
+
+      prog = re.compile(pat)
+      result = prog.match(str)
+
+   is equivalent to ::
+
+      result = re.match(pat, str)
+
+   but the version using :func:`compile` is more efficient when the expression will
+   be used several times in a single program.
+
+   .. % (The compiled version of the last pattern passed to
+   .. % \function{re.match()} or \function{re.search()} is cached, so
+   .. % programs that use only a single regular expression at a time needn't
+   .. % worry about compiling regular expressions.)
+
+
+.. data:: I
+          IGNORECASE
+
+   Perform case-insensitive matching; expressions like ``[A-Z]`` will match
+   lowercase letters, too.  This is not affected by the current locale.
+
+
+.. data:: L
+          LOCALE
+
+   Make ``\w``, ``\W``, ``\b``, ``\B``, ``\s`` and ``\S`` dependent on the current
+   locale.
+
+
+.. data:: M
+          MULTILINE
+
+   When specified, the pattern character ``'^'`` matches at the beginning of the
+   string and at the beginning of each line (immediately following each newline);
+   and the pattern character ``'$'`` matches at the end of the string and at the
+   end of each line (immediately preceding each newline).  By default, ``'^'``
+   matches only at the beginning of the string, and ``'$'`` only at the end of the
+   string and immediately before the newline (if any) at the end of the string.
+
+
+.. data:: S
+          DOTALL
+
+   Make the ``'.'`` special character match any character at all, including a
+   newline; without this flag, ``'.'`` will match anything *except* a newline.
+
+
+.. data:: U
+          UNICODE
+
+   Make ``\w``, ``\W``, ``\b``, ``\B``, ``\d``, ``\D``, ``\s`` and ``\S`` dependent
+   on the Unicode character properties database.
+
+   .. versionadded:: 2.0
+
+
+.. data:: X
+          VERBOSE
+
+   This flag allows you to write regular expressions that look nicer. Whitespace
+   within the pattern is ignored, except when in a character class or preceded by
+   an unescaped backslash, and, when a line contains a ``'#'`` neither in a
+   character class or preceded by an unescaped backslash, all characters from the
+   leftmost such ``'#'`` through the end of the line are ignored.
+
+   .. % XXX should add an example here
+
+
+.. function:: search(pattern, string[, flags])
+
+   Scan through *string* looking for a location where the regular expression
+   *pattern* produces a match, and return a corresponding :class:`MatchObject`
+   instance. Return ``None`` if no position in the string matches the pattern; note
+   that this is different from finding a zero-length match at some point in the
+   string.
+
+
+.. function:: match(pattern, string[, flags])
+
+   If zero or more characters at the beginning of *string* match the regular
+   expression *pattern*, return a corresponding :class:`MatchObject` instance.
+   Return ``None`` if the string does not match the pattern; note that this is
+   different from a zero-length match.
+
+   .. note::
+
+      If you want to locate a match anywhere in *string*, use :meth:`search` instead.
+
+
+.. function:: split(pattern, string[, maxsplit=0])
+
+   Split *string* by the occurrences of *pattern*.  If capturing parentheses are
+   used in *pattern*, then the text of all groups in the pattern are also returned
+   as part of the resulting list. If *maxsplit* is nonzero, at most *maxsplit*
+   splits occur, and the remainder of the string is returned as the final element
+   of the list.  (Incompatibility note: in the original Python 1.5 release,
+   *maxsplit* was ignored.  This has been fixed in later releases.) ::
+
+      >>> re.split('\W+', 'Words, words, words.')
+      ['Words', 'words', 'words', '']
+      >>> re.split('(\W+)', 'Words, words, words.')
+      ['Words', ', ', 'words', ', ', 'words', '.', '']
+      >>> re.split('\W+', 'Words, words, words.', 1)
+      ['Words', 'words, words.']
+
+
+.. function:: findall(pattern, string[, flags])
+
+   Return a list of all non-overlapping matches of *pattern* in *string*.  If one
+   or more groups are present in the pattern, return a list of groups; this will be
+   a list of tuples if the pattern has more than one group.  Empty matches are
+   included in the result unless they touch the beginning of another match.
+
+   .. versionadded:: 1.5.2
+
+   .. versionchanged:: 2.4
+      Added the optional flags argument.
+
+
+.. function:: finditer(pattern, string[, flags])
+
+   Return an iterator over all non-overlapping matches for the RE *pattern* in
+   *string*.  For each match, the iterator returns a match object.  Empty matches
+   are included in the result unless they touch the beginning of another match.
+
+   .. versionadded:: 2.2
+
+   .. versionchanged:: 2.4
+      Added the optional flags argument.
+
+
+.. function:: sub(pattern, repl, string[, count])
+
+   Return the string obtained by replacing the leftmost non-overlapping occurrences
+   of *pattern* in *string* by the replacement *repl*.  If the pattern isn't found,
+   *string* is returned unchanged.  *repl* can be a string or a function; if it is
+   a string, any backslash escapes in it are processed.  That is, ``\n`` is
+   converted to a single newline character, ``\r`` is converted to a linefeed, and
+   so forth.  Unknown escapes such as ``\j`` are left alone.  Backreferences, such
+   as ``\6``, are replaced with the substring matched by group 6 in the pattern.
+   For example::
+
+      >>> re.sub(r'def\s+([a-zA-Z_][a-zA-Z_0-9]*)\s*\(\s*\):',
+      ...        r'static PyObject*\npy_\1(void)\n{',
+      ...        'def myfunc():')
+      'static PyObject*\npy_myfunc(void)\n{'
+
+   If *repl* is a function, it is called for every non-overlapping occurrence of
+   *pattern*.  The function takes a single match object argument, and returns the
+   replacement string.  For example::
+
+      >>> def dashrepl(matchobj):
+      ...     if matchobj.group(0) == '-': return ' '
+      ...     else: return '-'
+      >>> re.sub('-{1,2}', dashrepl, 'pro----gram-files')
+      'pro--gram files'
+
+   The pattern may be a string or an RE object; if you need to specify regular
+   expression flags, you must use a RE object, or use embedded modifiers in a
+   pattern; for example, ``sub("(?i)b+", "x", "bbbb BBBB")`` returns ``'x x'``.
+
+   The optional argument *count* is the maximum number of pattern occurrences to be
+   replaced; *count* must be a non-negative integer.  If omitted or zero, all
+   occurrences will be replaced. Empty matches for the pattern are replaced only
+   when not adjacent to a previous match, so ``sub('x*', '-', 'abc')`` returns
+   ``'-a-b-c-'``.
+
+   In addition to character escapes and backreferences as described above,
+   ``\g`` will use the substring matched by the group named ``name``, as
+   defined by the ``(?P...)`` syntax. ``\g`` uses the corresponding
+   group number; ``\g<2>`` is therefore equivalent to ``\2``, but isn't ambiguous
+   in a replacement such as ``\g<2>0``.  ``\20`` would be interpreted as a
+   reference to group 20, not a reference to group 2 followed by the literal
+   character ``'0'``.  The backreference ``\g<0>`` substitutes in the entire
+   substring matched by the RE.
+
+
+.. function:: subn(pattern, repl, string[, count])
+
+   Perform the same operation as :func:`sub`, but return a tuple ``(new_string,
+   number_of_subs_made)``.
+
+
+.. function:: escape(string)
+
+   Return *string* with all non-alphanumerics backslashed; this is useful if you
+   want to match an arbitrary literal string that may have regular expression
+   metacharacters in it.
+
+
+.. exception:: error
+
+   Exception raised when a string passed to one of the functions here is not a
+   valid regular expression (for example, it might contain unmatched parentheses)
+   or when some other error occurs during compilation or matching.  It is never an
+   error if a string contains no match for a pattern.
+
+
+.. _re-objects:
+
+Regular Expression Objects
+--------------------------
+
+Compiled regular expression objects support the following methods and
+attributes:
+
+
+.. method:: RegexObject.match(string[, pos[, endpos]])
+
+   If zero or more characters at the beginning of *string* match this regular
+   expression, return a corresponding :class:`MatchObject` instance.  Return
+   ``None`` if the string does not match the pattern; note that this is different
+   from a zero-length match.
+
+   .. note::
+
+      If you want to locate a match anywhere in *string*, use :meth:`search` instead.
+
+   The optional second parameter *pos* gives an index in the string where the
+   search is to start; it defaults to ``0``.  This is not completely equivalent to
+   slicing the string; the ``'^'`` pattern character matches at the real beginning
+   of the string and at positions just after a newline, but not necessarily at the
+   index where the search is to start.
+
+   The optional parameter *endpos* limits how far the string will be searched; it
+   will be as if the string is *endpos* characters long, so only the characters
+   from *pos* to ``endpos - 1`` will be searched for a match.  If *endpos* is less
+   than *pos*, no match will be found, otherwise, if *rx* is a compiled regular
+   expression object, ``rx.match(string, 0, 50)`` is equivalent to
+   ``rx.match(string[:50], 0)``.
+
+
+.. method:: RegexObject.search(string[, pos[, endpos]])
+
+   Scan through *string* looking for a location where this regular expression
+   produces a match, and return a corresponding :class:`MatchObject` instance.
+   Return ``None`` if no position in the string matches the pattern; note that this
+   is different from finding a zero-length match at some point in the string.
+
+   The optional *pos* and *endpos* parameters have the same meaning as for the
+   :meth:`match` method.
+
+
+.. method:: RegexObject.split(string[, maxsplit=0])
+
+   Identical to the :func:`split` function, using the compiled pattern.
+
+
+.. method:: RegexObject.findall(string[, pos[, endpos]])
+
+   Identical to the :func:`findall` function, using the compiled pattern.
+
+
+.. method:: RegexObject.finditer(string[, pos[, endpos]])
+
+   Identical to the :func:`finditer` function, using the compiled pattern.
+
+
+.. method:: RegexObject.sub(repl, string[, count=0])
+
+   Identical to the :func:`sub` function, using the compiled pattern.
+
+
+.. method:: RegexObject.subn(repl, string[, count=0])
+
+   Identical to the :func:`subn` function, using the compiled pattern.
+
+
+.. attribute:: RegexObject.flags
+
+   The flags argument used when the RE object was compiled, or ``0`` if no flags
+   were provided.
+
+
+.. attribute:: RegexObject.groupindex
+
+   A dictionary mapping any symbolic group names defined by ``(?P)`` to group
+   numbers.  The dictionary is empty if no symbolic groups were used in the
+   pattern.
+
+
+.. attribute:: RegexObject.pattern
+
+   The pattern string from which the RE object was compiled.
+
+
+.. _match-objects:
+
+Match Objects
+-------------
+
+:class:`MatchObject` instances support the following methods and attributes:
+
+
+.. method:: MatchObject.expand(template)
+
+   Return the string obtained by doing backslash substitution on the template
+   string *template*, as done by the :meth:`sub` method. Escapes such as ``\n`` are
+   converted to the appropriate characters, and numeric backreferences (``\1``,
+   ``\2``) and named backreferences (``\g<1>``, ``\g``) are replaced by the
+   contents of the corresponding group.
+
+
+.. method:: MatchObject.group([group1, ...])
+
+   Returns one or more subgroups of the match.  If there is a single argument, the
+   result is a single string; if there are multiple arguments, the result is a
+   tuple with one item per argument. Without arguments, *group1* defaults to zero
+   (the whole match is returned). If a *groupN* argument is zero, the corresponding
+   return value is the entire matching string; if it is in the inclusive range
+   [1..99], it is the string matching the corresponding parenthesized group.  If a
+   group number is negative or larger than the number of groups defined in the
+   pattern, an :exc:`IndexError` exception is raised. If a group is contained in a
+   part of the pattern that did not match, the corresponding result is ``None``.
+   If a group is contained in a part of the pattern that matched multiple times,
+   the last match is returned.
+
+   If the regular expression uses the ``(?P...)`` syntax, the *groupN*
+   arguments may also be strings identifying groups by their group name.  If a
+   string argument is not used as a group name in the pattern, an :exc:`IndexError`
+   exception is raised.
+
+   A moderately complicated example::
+
+      m = re.match(r"(?P\d+)\.(\d*)", '3.14')
+
+   After performing this match, ``m.group(1)`` is ``'3'``, as is
+   ``m.group('int')``, and ``m.group(2)`` is ``'14'``.
+
+
+.. method:: MatchObject.groups([default])
+
+   Return a tuple containing all the subgroups of the match, from 1 up to however
+   many groups are in the pattern.  The *default* argument is used for groups that
+   did not participate in the match; it defaults to ``None``.  (Incompatibility
+   note: in the original Python 1.5 release, if the tuple was one element long, a
+   string would be returned instead.  In later versions (from 1.5.1 on), a
+   singleton tuple is returned in such cases.)
+
+
+.. method:: MatchObject.groupdict([default])
+
+   Return a dictionary containing all the *named* subgroups of the match, keyed by
+   the subgroup name.  The *default* argument is used for groups that did not
+   participate in the match; it defaults to ``None``.
+
+
+.. method:: MatchObject.start([group])
+            MatchObject.end([group])
+
+   Return the indices of the start and end of the substring matched by *group*;
+   *group* defaults to zero (meaning the whole matched substring). Return ``-1`` if
+   *group* exists but did not contribute to the match.  For a match object *m*, and
+   a group *g* that did contribute to the match, the substring matched by group *g*
+   (equivalent to ``m.group(g)``) is ::
+
+      m.string[m.start(g):m.end(g)]
+
+   Note that ``m.start(group)`` will equal ``m.end(group)`` if *group* matched a
+   null string.  For example, after ``m = re.search('b(c?)', 'cba')``,
+   ``m.start(0)`` is 1, ``m.end(0)`` is 2, ``m.start(1)`` and ``m.end(1)`` are both
+   2, and ``m.start(2)`` raises an :exc:`IndexError` exception.
+
+
+.. method:: MatchObject.span([group])
+
+   For :class:`MatchObject` *m*, return the 2-tuple ``(m.start(group),
+   m.end(group))``. Note that if *group* did not contribute to the match, this is
+   ``(-1, -1)``.  Again, *group* defaults to zero.
+
+
+.. attribute:: MatchObject.pos
+
+   The value of *pos* which was passed to the :func:`search` or :func:`match`
+   method of the :class:`RegexObject`.  This is the index into the string at which
+   the RE engine started looking for a match.
+
+
+.. attribute:: MatchObject.endpos
+
+   The value of *endpos* which was passed to the :func:`search` or :func:`match`
+   method of the :class:`RegexObject`.  This is the index into the string beyond
+   which the RE engine will not go.
+
+
+.. attribute:: MatchObject.lastindex
+
+   The integer index of the last matched capturing group, or ``None`` if no group
+   was matched at all. For example, the expressions ``(a)b``, ``((a)(b))``, and
+   ``((ab))`` will have ``lastindex == 1`` if applied to the string ``'ab'``, while
+   the expression ``(a)(b)`` will have ``lastindex == 2``, if applied to the same
+   string.
+
+
+.. attribute:: MatchObject.lastgroup
+
+   The name of the last matched capturing group, or ``None`` if the group didn't
+   have a name, or if no group was matched at all.
+
+
+.. attribute:: MatchObject.re
+
+   The regular expression object whose :meth:`match` or :meth:`search` method
+   produced this :class:`MatchObject` instance.
+
+
+.. attribute:: MatchObject.string
+
+   The string passed to :func:`match` or :func:`search`.
+
+
+Examples
+--------
+
+**Simulating scanf()**
+
+.. index:: single: scanf()
+
+Python does not currently have an equivalent to :cfunc:`scanf`.  Regular
+expressions are generally more powerful, though also more verbose, than
+:cfunc:`scanf` format strings.  The table below offers some more-or-less
+equivalent mappings between :cfunc:`scanf` format tokens and regular
+expressions.
+
++--------------------------------+---------------------------------------------+
+| :cfunc:`scanf` Token           | Regular Expression                          |
++================================+=============================================+
+| ``%c``                         | ``.``                                       |
++--------------------------------+---------------------------------------------+
+| ``%5c``                        | ``.{5}``                                    |
++--------------------------------+---------------------------------------------+
+| ``%d``                         | ``[-+]?\d+``                                |
++--------------------------------+---------------------------------------------+
+| ``%e``, ``%E``, ``%f``, ``%g`` | ``[-+]?(\d+(\.\d*)?|\.\d+)([eE][-+]?\d+)?`` |
++--------------------------------+---------------------------------------------+
+| ``%i``                         | ``[-+]?(0[xX][\dA-Fa-f]+|0[0-7]*|\d+)``     |
++--------------------------------+---------------------------------------------+
+| ``%o``                         | ``0[0-7]*``                                 |
++--------------------------------+---------------------------------------------+
+| ``%s``                         | ``\S+``                                     |
++--------------------------------+---------------------------------------------+
+| ``%u``                         | ``\d+``                                     |
++--------------------------------+---------------------------------------------+
+| ``%x``, ``%X``                 | ``0[xX][\dA-Fa-f]+``                        |
++--------------------------------+---------------------------------------------+
+
+To extract the filename and numbers from a string like ::
+
+   /usr/sbin/sendmail - 0 errors, 4 warnings
+
+you would use a :cfunc:`scanf` format like ::
+
+   %s - %d errors, %d warnings
+
+The equivalent regular expression would be ::
+
+   (\S+) - (\d+) errors, (\d+) warnings
+
+**Avoiding recursion**
+
+If you create regular expressions that require the engine to perform a lot of
+recursion, you may encounter a :exc:`RuntimeError` exception with the message
+``maximum recursion limit`` exceeded. For example, ::
+
+   >>> import re
+   >>> s = 'Begin ' + 1000*'a very long string ' + 'end'
+   >>> re.match('Begin (\w| )*? end', s).end()
+   Traceback (most recent call last):
+     File "", line 1, in ?
+     File "/usr/local/lib/python2.5/re.py", line 132, in match
+       return _compile(pattern, flags).match(string)
+   RuntimeError: maximum recursion limit exceeded
+
+You can often restructure your regular expression to avoid recursion.
+
+Starting with Python 2.3, simple uses of the ``*?`` pattern are special-cased to
+avoid recursion.  Thus, the above regular expression can avoid recursion by
+being recast as ``Begin [a-zA-Z0-9_ ]*?end``.  As a further benefit, such
+regular expressions will run faster than their recursive equivalents.
+
diff --git a/Doc/library/readline.rst b/Doc/library/readline.rst
new file mode 100644
index 0000000..9a40747
--- /dev/null
+++ b/Doc/library/readline.rst
@@ -0,0 +1,222 @@
+
+:mod:`readline` --- GNU readline interface
+==========================================
+
+.. module:: readline
+   :platform: Unix
+   :synopsis: GNU readline support for Python.
+.. sectionauthor:: Skip Montanaro 
+
+
+The :mod:`readline` module defines a number of functions to facilitate
+completion and reading/writing of history files from the Python interpreter.
+This module can be used directly or via the :mod:`rlcompleter` module.  Settings
+made using  this module affect the behaviour of both the interpreter's
+interactive prompt  and the prompts offered by the :func:`raw_input` and
+:func:`input` built-in functions.
+
+The :mod:`readline` module defines the following functions:
+
+
+.. function:: parse_and_bind(string)
+
+   Parse and execute single line of a readline init file.
+
+
+.. function:: get_line_buffer()
+
+   Return the current contents of the line buffer.
+
+
+.. function:: insert_text(string)
+
+   Insert text into the command line.
+
+
+.. function:: read_init_file([filename])
+
+   Parse a readline initialization file. The default filename is the last filename
+   used.
+
+
+.. function:: read_history_file([filename])
+
+   Load a readline history file. The default filename is :file:`~/.history`.
+
+
+.. function:: write_history_file([filename])
+
+   Save a readline history file. The default filename is :file:`~/.history`.
+
+
+.. function:: clear_history()
+
+   Clear the current history.  (Note: this function is not available if the
+   installed version of GNU readline doesn't support it.)
+
+   .. versionadded:: 2.4
+
+
+.. function:: get_history_length()
+
+   Return the desired length of the history file.  Negative values imply unlimited
+   history file size.
+
+
+.. function:: set_history_length(length)
+
+   Set the number of lines to save in the history file. :func:`write_history_file`
+   uses this value to truncate the history file when saving.  Negative values imply
+   unlimited history file size.
+
+
+.. function:: get_current_history_length()
+
+   Return the number of lines currently in the history.  (This is different from
+   :func:`get_history_length`, which returns the maximum number of lines that will
+   be written to a history file.)
+
+   .. versionadded:: 2.3
+
+
+.. function:: get_history_item(index)
+
+   Return the current contents of history item at *index*.
+
+   .. versionadded:: 2.3
+
+
+.. function:: remove_history_item(pos)
+
+   Remove history item specified by its position from the history.
+
+   .. versionadded:: 2.4
+
+
+.. function:: replace_history_item(pos, line)
+
+   Replace history item specified by its position with the given line.
+
+   .. versionadded:: 2.4
+
+
+.. function:: redisplay()
+
+   Change what's displayed on the screen to reflect the current contents of the
+   line buffer.
+
+   .. versionadded:: 2.3
+
+
+.. function:: set_startup_hook([function])
+
+   Set or remove the startup_hook function.  If *function* is specified, it will be
+   used as the new startup_hook function; if omitted or ``None``, any hook function
+   already installed is removed.  The startup_hook function is called with no
+   arguments just before readline prints the first prompt.
+
+
+.. function:: set_pre_input_hook([function])
+
+   Set or remove the pre_input_hook function.  If *function* is specified, it will
+   be used as the new pre_input_hook function; if omitted or ``None``, any hook
+   function already installed is removed.  The pre_input_hook function is called
+   with no arguments after the first prompt has been printed and just before
+   readline starts reading input characters.
+
+
+.. function:: set_completer([function])
+
+   Set or remove the completer function.  If *function* is specified, it will be
+   used as the new completer function; if omitted or ``None``, any completer
+   function already installed is removed.  The completer function is called as
+   ``function(text, state)``, for *state* in ``0``, ``1``, ``2``, ..., until it
+   returns a non-string value.  It should return the next possible completion
+   starting with *text*.
+
+
+.. function:: get_completer()
+
+   Get the completer function, or ``None`` if no completer function has been set.
+
+   .. versionadded:: 2.3
+
+
+.. function:: get_begidx()
+
+   Get the beginning index of the readline tab-completion scope.
+
+
+.. function:: get_endidx()
+
+   Get the ending index of the readline tab-completion scope.
+
+
+.. function:: set_completer_delims(string)
+
+   Set the readline word delimiters for tab-completion.
+
+
+.. function:: get_completer_delims()
+
+   Get the readline word delimiters for tab-completion.
+
+
+.. function:: add_history(line)
+
+   Append a line to the history buffer, as if it was the last line typed.
+
+
+.. seealso::
+
+   Module :mod:`rlcompleter`
+      Completion of Python identifiers at the interactive prompt.
+
+
+.. _readline-example:
+
+Example
+-------
+
+The following example demonstrates how to use the :mod:`readline` module's
+history reading and writing functions to automatically load and save a history
+file named :file:`.pyhist` from the user's home directory.  The code below would
+normally be executed automatically during interactive sessions from the user's
+:envvar:`PYTHONSTARTUP` file. ::
+
+   import os
+   histfile = os.path.join(os.environ["HOME"], ".pyhist")
+   try:
+       readline.read_history_file(histfile)
+   except IOError:
+       pass
+   import atexit
+   atexit.register(readline.write_history_file, histfile)
+   del os, histfile
+
+The following example extends the :class:`code.InteractiveConsole` class to
+support history save/restore. ::
+
+   import code
+   import readline
+   import atexit
+   import os
+
+   class HistoryConsole(code.InteractiveConsole):
+       def __init__(self, locals=None, filename="",
+                    histfile=os.path.expanduser("~/.console-history")):
+           code.InteractiveConsole.__init__(self)
+           self.init_history(histfile)
+
+       def init_history(self, histfile):
+           readline.parse_and_bind("tab: complete")
+           if hasattr(readline, "read_history_file"):
+               try:
+                   readline.read_history_file(histfile)
+               except IOError:
+                   pass
+               atexit.register(self.save_history, histfile)
+
+       def save_history(self, histfile):
+           readline.write_history_file(histfile)
+
diff --git a/Doc/library/repr.rst b/Doc/library/repr.rst
new file mode 100644
index 0000000..493e2b3
--- /dev/null
+++ b/Doc/library/repr.rst
@@ -0,0 +1,136 @@
+
+:mod:`repr` --- Alternate :func:`repr` implementation
+=====================================================
+
+.. module:: repr
+   :synopsis: Alternate repr() implementation with size limits.
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+The :mod:`repr` module provides a means for producing object representations
+with limits on the size of the resulting strings. This is used in the Python
+debugger and may be useful in other contexts as well.
+
+This module provides a class, an instance, and a function:
+
+
+.. class:: Repr()
+
+   Class which provides formatting services useful in implementing functions
+   similar to the built-in :func:`repr`; size limits for  different object types
+   are added to avoid the generation of representations which are excessively long.
+
+
+.. data:: aRepr
+
+   This is an instance of :class:`Repr` which is used to provide the :func:`repr`
+   function described below.  Changing the attributes of this object will affect
+   the size limits used by :func:`repr` and the Python debugger.
+
+
+.. function:: repr(obj)
+
+   This is the :meth:`repr` method of ``aRepr``.  It returns a string similar to
+   that returned by the built-in function of the same  name, but with limits on
+   most sizes.
+
+
+.. _repr-objects:
+
+Repr Objects
+------------
+
+:class:`Repr` instances provide several members which can be used to provide
+size limits for the representations of different object types,  and methods
+which format specific object types.
+
+
+.. attribute:: Repr.maxlevel
+
+   Depth limit on the creation of recursive representations.  The default is ``6``.
+
+
+.. attribute:: Repr.maxdict
+               Repr.maxlist
+               Repr.maxtuple
+               Repr.maxset
+               Repr.maxfrozenset
+               Repr.maxdeque
+               Repr.maxarray
+
+   Limits on the number of entries represented for the named object type.  The
+   default is ``4`` for :attr:`maxdict`, ``5`` for :attr:`maxarray`, and  ``6`` for
+   the others.
+
+   .. versionadded:: 2.4
+      :attr:`maxset`, :attr:`maxfrozenset`, and :attr:`set`.
+
+
+.. attribute:: Repr.maxlong
+
+   Maximum number of characters in the representation for a long integer.  Digits
+   are dropped from the middle.  The default is ``40``.
+
+
+.. attribute:: Repr.maxstring
+
+   Limit on the number of characters in the representation of the string.  Note
+   that the "normal" representation of the string is used as the character source:
+   if escape sequences are needed in the representation, these may be mangled when
+   the representation is shortened.  The default is ``30``.
+
+
+.. attribute:: Repr.maxother
+
+   This limit is used to control the size of object types for which no specific
+   formatting method is available on the :class:`Repr` object. It is applied in a
+   similar manner as :attr:`maxstring`.  The default is ``20``.
+
+
+.. method:: Repr.repr(obj)
+
+   The equivalent to the built-in :func:`repr` that uses the formatting imposed by
+   the instance.
+
+
+.. method:: Repr.repr1(obj, level)
+
+   Recursive implementation used by :meth:`repr`.  This uses the type of *obj* to
+   determine which formatting method to call, passing it *obj* and *level*.  The
+   type-specific methods should call :meth:`repr1` to perform recursive formatting,
+   with ``level - 1`` for the value of *level* in the recursive  call.
+
+
+.. method:: Repr.repr_TYPE(obj, level)
+   :noindex:
+
+   Formatting methods for specific types are implemented as methods with a name
+   based on the type name.  In the method name, **TYPE** is replaced by
+   ``string.join(string.split(type(obj).__name__, '_'))``. Dispatch to these
+   methods is handled by :meth:`repr1`. Type-specific methods which need to
+   recursively format a value should call ``self.repr1(subobj, level - 1)``.
+
+
+.. _subclassing-reprs:
+
+Subclassing Repr Objects
+------------------------
+
+The use of dynamic dispatching by :meth:`Repr.repr1` allows subclasses of
+:class:`Repr` to add support for additional built-in object types or to modify
+the handling of types already supported. This example shows how special support
+for file objects could be added::
+
+   import repr
+   import sys
+
+   class MyRepr(repr.Repr):
+       def repr_file(self, obj, level):
+           if obj.name in ['', '', '']:
+               return obj.name
+           else:
+               return `obj`
+
+   aRepr = MyRepr()
+   print aRepr.repr(sys.stdin)          # prints ''
+
diff --git a/Doc/library/resource.rst b/Doc/library/resource.rst
new file mode 100644
index 0000000..834dace
--- /dev/null
+++ b/Doc/library/resource.rst
@@ -0,0 +1,238 @@
+
+:mod:`resource` --- Resource usage information
+==============================================
+
+.. module:: resource
+   :platform: Unix
+   :synopsis: An interface to provide resource usage information on the current process.
+.. moduleauthor:: Jeremy Hylton 
+.. sectionauthor:: Jeremy Hylton 
+
+
+This module provides basic mechanisms for measuring and controlling system
+resources utilized by a program.
+
+Symbolic constants are used to specify particular system resources and to
+request usage information about either the current process or its children.
+
+A single exception is defined for errors:
+
+
+.. exception:: error
+
+   The functions described below may raise this error if the underlying system call
+   failures unexpectedly.
+
+
+Resource Limits
+---------------
+
+Resources usage can be limited using the :func:`setrlimit` function described
+below. Each resource is controlled by a pair of limits: a soft limit and a hard
+limit. The soft limit is the current limit, and may be lowered or raised by a
+process over time. The soft limit can never exceed the hard limit. The hard
+limit can be lowered to any value greater than the soft limit, but not raised.
+(Only processes with the effective UID of the super-user can raise a hard
+limit.)
+
+The specific resources that can be limited are system dependent. They are
+described in the :manpage:`getrlimit(2)` man page.  The resources listed below
+are supported when the underlying operating system supports them; resources
+which cannot be checked or controlled by the operating system are not defined in
+this module for those platforms.
+
+
+.. function:: getrlimit(resource)
+
+   Returns a tuple ``(soft, hard)`` with the current soft and hard limits of
+   *resource*. Raises :exc:`ValueError` if an invalid resource is specified, or
+   :exc:`error` if the underlying system call fails unexpectedly.
+
+
+.. function:: setrlimit(resource, limits)
+
+   Sets new limits of consumption of *resource*. The *limits* argument must be a
+   tuple ``(soft, hard)`` of two integers describing the new limits. A value of
+   ``-1`` can be used to specify the maximum possible upper limit.
+
+   Raises :exc:`ValueError` if an invalid resource is specified, if the new soft
+   limit exceeds the hard limit, or if a process tries to raise its hard limit
+   (unless the process has an effective UID of super-user).  Can also raise
+   :exc:`error` if the underlying system call fails.
+
+These symbols define resources whose consumption can be controlled using the
+:func:`setrlimit` and :func:`getrlimit` functions described below. The values of
+these symbols are exactly the constants used by C programs.
+
+The Unix man page for :manpage:`getrlimit(2)` lists the available resources.
+Note that not all systems use the same symbol or same value to denote the same
+resource.  This module does not attempt to mask platform differences --- symbols
+not defined for a platform will not be available from this module on that
+platform.
+
+
+.. data:: RLIMIT_CORE
+
+   The maximum size (in bytes) of a core file that the current process can create.
+   This may result in the creation of a partial core file if a larger core would be
+   required to contain the entire process image.
+
+
+.. data:: RLIMIT_CPU
+
+   The maximum amount of processor time (in seconds) that a process can use. If
+   this limit is exceeded, a :const:`SIGXCPU` signal is sent to the process. (See
+   the :mod:`signal` module documentation for information about how to catch this
+   signal and do something useful, e.g. flush open files to disk.)
+
+
+.. data:: RLIMIT_FSIZE
+
+   The maximum size of a file which the process may create.  This only affects the
+   stack of the main thread in a multi-threaded process.
+
+
+.. data:: RLIMIT_DATA
+
+   The maximum size (in bytes) of the process's heap.
+
+
+.. data:: RLIMIT_STACK
+
+   The maximum size (in bytes) of the call stack for the current process.
+
+
+.. data:: RLIMIT_RSS
+
+   The maximum resident set size that should be made available to the process.
+
+
+.. data:: RLIMIT_NPROC
+
+   The maximum number of processes the current process may create.
+
+
+.. data:: RLIMIT_NOFILE
+
+   The maximum number of open file descriptors for the current process.
+
+
+.. data:: RLIMIT_OFILE
+
+   The BSD name for :const:`RLIMIT_NOFILE`.
+
+
+.. data:: RLIMIT_MEMLOCK
+
+   The maximum address space which may be locked in memory.
+
+
+.. data:: RLIMIT_VMEM
+
+   The largest area of mapped memory which the process may occupy.
+
+
+.. data:: RLIMIT_AS
+
+   The maximum area (in bytes) of address space which may be taken by the process.
+
+
+Resource Usage
+--------------
+
+These functions are used to retrieve resource usage information:
+
+
+.. function:: getrusage(who)
+
+   This function returns an object that describes the resources consumed by either
+   the current process or its children, as specified by the *who* parameter.  The
+   *who* parameter should be specified using one of the :const:`RUSAGE_\*`
+   constants described below.
+
+   The fields of the return value each describe how a particular system resource
+   has been used, e.g. amount of time spent running is user mode or number of times
+   the process was swapped out of main memory. Some values are dependent on the
+   clock tick internal, e.g. the amount of memory the process is using.
+
+   For backward compatibility, the return value is also accessible as a tuple of 16
+   elements.
+
+   The fields :attr:`ru_utime` and :attr:`ru_stime` of the return value are
+   floating point values representing the amount of time spent executing in user
+   mode and the amount of time spent executing in system mode, respectively. The
+   remaining values are integers. Consult the :manpage:`getrusage(2)` man page for
+   detailed information about these values. A brief summary is presented here:
+
+   +--------+---------------------+-------------------------------+
+   | Index  | Field               | Resource                      |
+   +========+=====================+===============================+
+   | ``0``  | :attr:`ru_utime`    | time in user mode (float)     |
+   +--------+---------------------+-------------------------------+
+   | ``1``  | :attr:`ru_stime`    | time in system mode (float)   |
+   +--------+---------------------+-------------------------------+
+   | ``2``  | :attr:`ru_maxrss`   | maximum resident set size     |
+   +--------+---------------------+-------------------------------+
+   | ``3``  | :attr:`ru_ixrss`    | shared memory size            |
+   +--------+---------------------+-------------------------------+
+   | ``4``  | :attr:`ru_idrss`    | unshared memory size          |
+   +--------+---------------------+-------------------------------+
+   | ``5``  | :attr:`ru_isrss`    | unshared stack size           |
+   +--------+---------------------+-------------------------------+
+   | ``6``  | :attr:`ru_minflt`   | page faults not requiring I/O |
+   +--------+---------------------+-------------------------------+
+   | ``7``  | :attr:`ru_majflt`   | page faults requiring I/O     |
+   +--------+---------------------+-------------------------------+
+   | ``8``  | :attr:`ru_nswap`    | number of swap outs           |
+   +--------+---------------------+-------------------------------+
+   | ``9``  | :attr:`ru_inblock`  | block input operations        |
+   +--------+---------------------+-------------------------------+
+   | ``10`` | :attr:`ru_oublock`  | block output operations       |
+   +--------+---------------------+-------------------------------+
+   | ``11`` | :attr:`ru_msgsnd`   | messages sent                 |
+   +--------+---------------------+-------------------------------+
+   | ``12`` | :attr:`ru_msgrcv`   | messages received             |
+   +--------+---------------------+-------------------------------+
+   | ``13`` | :attr:`ru_nsignals` | signals received              |
+   +--------+---------------------+-------------------------------+
+   | ``14`` | :attr:`ru_nvcsw`    | voluntary context switches    |
+   +--------+---------------------+-------------------------------+
+   | ``15`` | :attr:`ru_nivcsw`   | involuntary context switches  |
+   +--------+---------------------+-------------------------------+
+
+   This function will raise a :exc:`ValueError` if an invalid *who* parameter is
+   specified. It may also raise :exc:`error` exception in unusual circumstances.
+
+   .. versionchanged:: 2.3
+      Added access to values as attributes of the returned object.
+
+
+.. function:: getpagesize()
+
+   Returns the number of bytes in a system page. (This need not be the same as the
+   hardware page size.) This function is useful for determining the number of bytes
+   of memory a process is using. The third element of the tuple returned by
+   :func:`getrusage` describes memory usage in pages; multiplying by page size
+   produces number of bytes.
+
+The following :const:`RUSAGE_\*` symbols are passed to the :func:`getrusage`
+function to specify which processes information should be provided for.
+
+
+.. data:: RUSAGE_SELF
+
+   :const:`RUSAGE_SELF` should be used to request information pertaining only to
+   the process itself.
+
+
+.. data:: RUSAGE_CHILDREN
+
+   Pass to :func:`getrusage` to request resource information for child processes of
+   the calling process.
+
+
+.. data:: RUSAGE_BOTH
+
+   Pass to :func:`getrusage` to request resources consumed by both the current
+   process and child processes.  May not be available on all systems.
+
diff --git a/Doc/library/rfc822.rst b/Doc/library/rfc822.rst
new file mode 100644
index 0000000..fa25ba5
--- /dev/null
+++ b/Doc/library/rfc822.rst
@@ -0,0 +1,351 @@
+
+:mod:`rfc822` --- Parse RFC 2822 mail headers
+=============================================
+
+.. module:: rfc822
+   :synopsis: Parse 2822 style mail messages.
+
+
+.. deprecated:: 2.3
+   The :mod:`email` package should be used in preference to the :mod:`rfc822`
+   module.  This module is present only to maintain backward compatibility.
+
+This module defines a class, :class:`Message`, which represents an "email
+message" as defined by the Internet standard :rfc:`2822`. [#]_  Such messages
+consist of a collection of message headers, and a message body.  This module
+also defines a helper class :class:`AddressList` for parsing :rfc:`2822`
+addresses.  Please refer to the RFC for information on the specific syntax of
+:rfc:`2822` messages.
+
+.. index:: module: mailbox
+
+The :mod:`mailbox` module provides classes  to read mailboxes produced by
+various end-user mail programs.
+
+
+.. class:: Message(file[, seekable])
+
+   A :class:`Message` instance is instantiated with an input object as parameter.
+   Message relies only on the input object having a :meth:`readline` method; in
+   particular, ordinary file objects qualify.  Instantiation reads headers from the
+   input object up to a delimiter line (normally a blank line) and stores them in
+   the instance.  The message body, following the headers, is not consumed.
+
+   This class can work with any input object that supports a :meth:`readline`
+   method.  If the input object has seek and tell capability, the
+   :meth:`rewindbody` method will work; also, illegal lines will be pushed back
+   onto the input stream.  If the input object lacks seek but has an :meth:`unread`
+   method that can push back a line of input, :class:`Message` will use that to
+   push back illegal lines.  Thus this class can be used to parse messages coming
+   from a buffered stream.
+
+   The optional *seekable* argument is provided as a workaround for certain stdio
+   libraries in which :cfunc:`tell` discards buffered data before discovering that
+   the :cfunc:`lseek` system call doesn't work.  For maximum portability, you
+   should set the seekable argument to zero to prevent that initial :meth:`tell`
+   when passing in an unseekable object such as a file object created from a socket
+   object.
+
+   Input lines as read from the file may either be terminated by CR-LF or by a
+   single linefeed; a terminating CR-LF is replaced by a single linefeed before the
+   line is stored.
+
+   All header matching is done independent of upper or lower case; e.g.
+   ``m['From']``, ``m['from']`` and ``m['FROM']`` all yield the same result.
+
+
+.. class:: AddressList(field)
+
+   You may instantiate the :class:`AddressList` helper class using a single string
+   parameter, a comma-separated list of :rfc:`2822` addresses to be parsed.  (The
+   parameter ``None`` yields an empty list.)
+
+
+.. function:: quote(str)
+
+   Return a new string with backslashes in *str* replaced by two backslashes and
+   double quotes replaced by backslash-double quote.
+
+
+.. function:: unquote(str)
+
+   Return a new string which is an *unquoted* version of *str*. If *str* ends and
+   begins with double quotes, they are stripped off.  Likewise if *str* ends and
+   begins with angle brackets, they are stripped off.
+
+
+.. function:: parseaddr(address)
+
+   Parse *address*, which should be the value of some address-containing field such
+   as :mailheader:`To` or :mailheader:`Cc`, into its constituent "realname" and
+   "email address" parts. Returns a tuple of that information, unless the parse
+   fails, in which case a 2-tuple ``(None, None)`` is returned.
+
+
+.. function:: dump_address_pair(pair)
+
+   The inverse of :meth:`parseaddr`, this takes a 2-tuple of the form ``(realname,
+   email_address)`` and returns the string value suitable for a :mailheader:`To` or
+   :mailheader:`Cc` header.  If the first element of *pair* is false, then the
+   second element is returned unmodified.
+
+
+.. function:: parsedate(date)
+
+   Attempts to parse a date according to the rules in :rfc:`2822`. however, some
+   mailers don't follow that format as specified, so :func:`parsedate` tries to
+   guess correctly in such cases.  *date* is a string containing an :rfc:`2822`
+   date, such as  ``'Mon, 20 Nov 1995 19:12:08 -0500'``.  If it succeeds in parsing
+   the date, :func:`parsedate` returns a 9-tuple that can be passed directly to
+   :func:`time.mktime`; otherwise ``None`` will be returned.  Note that indexes 6,
+   7, and 8 of the result tuple are not usable.
+
+
+.. function:: parsedate_tz(date)
+
+   Performs the same function as :func:`parsedate`, but returns either ``None`` or
+   a 10-tuple; the first 9 elements make up a tuple that can be passed directly to
+   :func:`time.mktime`, and the tenth is the offset of the date's timezone from UTC
+   (which is the official term for Greenwich Mean Time).  (Note that the sign of
+   the timezone offset is the opposite of the sign of the ``time.timezone``
+   variable for the same timezone; the latter variable follows the POSIX standard
+   while this module follows :rfc:`2822`.)  If the input string has no timezone,
+   the last element of the tuple returned is ``None``.  Note that indexes 6, 7, and
+   8 of the result tuple are not usable.
+
+
+.. function:: mktime_tz(tuple)
+
+   Turn a 10-tuple as returned by :func:`parsedate_tz` into a UTC timestamp.  If
+   the timezone item in the tuple is ``None``, assume local time.  Minor
+   deficiency: this first interprets the first 8 elements as a local time and then
+   compensates for the timezone difference; this may yield a slight error around
+   daylight savings time switch dates.  Not enough to worry about for common use.
+
+
+.. seealso::
+
+   Module :mod:`email`
+      Comprehensive email handling package; supersedes the :mod:`rfc822` module.
+
+   Module :mod:`mailbox`
+      Classes to read various mailbox formats produced  by end-user mail programs.
+
+   Module :mod:`mimetools`
+      Subclass of :class:`rfc822.Message` that handles MIME encoded messages.
+
+
+.. _message-objects:
+
+Message Objects
+---------------
+
+A :class:`Message` instance has the following methods:
+
+
+.. method:: Message.rewindbody()
+
+   Seek to the start of the message body.  This only works if the file object is
+   seekable.
+
+
+.. method:: Message.isheader(line)
+
+   Returns a line's canonicalized fieldname (the dictionary key that will be used
+   to index it) if the line is a legal :rfc:`2822` header; otherwise returns
+   ``None`` (implying that parsing should stop here and the line be pushed back on
+   the input stream).  It is sometimes useful to override this method in a
+   subclass.
+
+
+.. method:: Message.islast(line)
+
+   Return true if the given line is a delimiter on which Message should stop.  The
+   delimiter line is consumed, and the file object's read location positioned
+   immediately after it.  By default this method just checks that the line is
+   blank, but you can override it in a subclass.
+
+
+.. method:: Message.iscomment(line)
+
+   Return ``True`` if the given line should be ignored entirely, just skipped. By
+   default this is a stub that always returns ``False``, but you can override it in
+   a subclass.
+
+
+.. method:: Message.getallmatchingheaders(name)
+
+   Return a list of lines consisting of all headers matching *name*, if any.  Each
+   physical line, whether it is a continuation line or not, is a separate list
+   item.  Return the empty list if no header matches *name*.
+
+
+.. method:: Message.getfirstmatchingheader(name)
+
+   Return a list of lines comprising the first header matching *name*, and its
+   continuation line(s), if any.  Return ``None`` if there is no header matching
+   *name*.
+
+
+.. method:: Message.getrawheader(name)
+
+   Return a single string consisting of the text after the colon in the first
+   header matching *name*.  This includes leading whitespace, the trailing
+   linefeed, and internal linefeeds and whitespace if there any continuation
+   line(s) were present.  Return ``None`` if there is no header matching *name*.
+
+
+.. method:: Message.getheader(name[, default])
+
+   Like ``getrawheader(name)``, but strip leading and trailing whitespace.
+   Internal whitespace is not stripped.  The optional *default* argument can be
+   used to specify a different default to be returned when there is no header
+   matching *name*.
+
+
+.. method:: Message.get(name[, default])
+
+   An alias for :meth:`getheader`, to make the interface more compatible  with
+   regular dictionaries.
+
+
+.. method:: Message.getaddr(name)
+
+   Return a pair ``(full name, email address)`` parsed from the string returned by
+   ``getheader(name)``.  If no header matching *name* exists, return ``(None,
+   None)``; otherwise both the full name and the address are (possibly empty)
+   strings.
+
+   Example: If *m*'s first :mailheader:`From` header contains the string
+   ``'jack@cwi.nl (Jack Jansen)'``, then ``m.getaddr('From')`` will yield the pair
+   ``('Jack Jansen', 'jack@cwi.nl')``. If the header contained ``'Jack Jansen
+   '`` instead, it would yield the exact same result.
+
+
+.. method:: Message.getaddrlist(name)
+
+   This is similar to ``getaddr(list)``, but parses a header containing a list of
+   email addresses (e.g. a :mailheader:`To` header) and returns a list of ``(full
+   name, email address)`` pairs (even if there was only one address in the header).
+   If there is no header matching *name*, return an empty list.
+
+   If multiple headers exist that match the named header (e.g. if there are several
+   :mailheader:`Cc` headers), all are parsed for addresses. Any continuation lines
+   the named headers contain are also parsed.
+
+
+.. method:: Message.getdate(name)
+
+   Retrieve a header using :meth:`getheader` and parse it into a 9-tuple compatible
+   with :func:`time.mktime`; note that fields 6, 7, and 8  are not usable.  If
+   there is no header matching *name*, or it is unparsable, return ``None``.
+
+   Date parsing appears to be a black art, and not all mailers adhere to the
+   standard.  While it has been tested and found correct on a large collection of
+   email from many sources, it is still possible that this function may
+   occasionally yield an incorrect result.
+
+
+.. method:: Message.getdate_tz(name)
+
+   Retrieve a header using :meth:`getheader` and parse it into a 10-tuple; the
+   first 9 elements will make a tuple compatible with :func:`time.mktime`, and the
+   10th is a number giving the offset of the date's timezone from UTC.  Note that
+   fields 6, 7, and 8  are not usable.  Similarly to :meth:`getdate`, if there is
+   no header matching *name*, or it is unparsable, return ``None``.
+
+:class:`Message` instances also support a limited mapping interface. In
+particular: ``m[name]`` is like ``m.getheader(name)`` but raises :exc:`KeyError`
+if there is no matching header; and ``len(m)``, ``m.get(name[, default])``,
+``m.has_key(name)``, ``m.keys()``, ``m.values()`` ``m.items()``, and
+``m.setdefault(name[, default])`` act as expected, with the one difference
+that :meth:`setdefault` uses an empty string as the default value.
+:class:`Message` instances also support the mapping writable interface ``m[name]
+= value`` and ``del m[name]``.  :class:`Message` objects do not support the
+:meth:`clear`, :meth:`copy`, :meth:`popitem`, or :meth:`update` methods of the
+mapping interface.  (Support for :meth:`get` and :meth:`setdefault` was only
+added in Python 2.2.)
+
+Finally, :class:`Message` instances have some public instance variables:
+
+
+.. attribute:: Message.headers
+
+   A list containing the entire set of header lines, in the order in which they
+   were read (except that setitem calls may disturb this order). Each line contains
+   a trailing newline.  The blank line terminating the headers is not contained in
+   the list.
+
+
+.. attribute:: Message.fp
+
+   The file or file-like object passed at instantiation time.  This can be used to
+   read the message content.
+
+
+.. attribute:: Message.unixfrom
+
+   The Unix ``From`` line, if the message had one, or an empty string.  This is
+   needed to regenerate the message in some contexts, such as an ``mbox``\ -style
+   mailbox file.
+
+
+.. _addresslist-objects:
+
+AddressList Objects
+-------------------
+
+An :class:`AddressList` instance has the following methods:
+
+
+.. method:: AddressList.__len__()
+
+   Return the number of addresses in the address list.
+
+
+.. method:: AddressList.__str__()
+
+   Return a canonicalized string representation of the address list. Addresses are
+   rendered in "name"  form, comma-separated.
+
+
+.. method:: AddressList.__add__(alist)
+
+   Return a new :class:`AddressList` instance that contains all addresses in both
+   :class:`AddressList` operands, with duplicates removed (set union).
+
+
+.. method:: AddressList.__iadd__(alist)
+
+   In-place version of :meth:`__add__`; turns this :class:`AddressList` instance
+   into the union of itself and the right-hand instance, *alist*.
+
+
+.. method:: AddressList.__sub__(alist)
+
+   Return a new :class:`AddressList` instance that contains every address in the
+   left-hand :class:`AddressList` operand that is not present in the right-hand
+   address operand (set difference).
+
+
+.. method:: AddressList.__isub__(alist)
+
+   In-place version of :meth:`__sub__`, removing addresses in this list which are
+   also in *alist*.
+
+Finally, :class:`AddressList` instances have one public instance variable:
+
+
+.. attribute:: AddressList.addresslist
+
+   A list of tuple string pairs, one per address.  In each member, the first is the
+   canonicalized name part, the second is the actual route-address (``'@'``\
+   -separated username-host.domain pair).
+
+.. rubric:: Footnotes
+
+.. [#] This module originally conformed to :rfc:`822`, hence the name.  Since then,
+   :rfc:`2822` has been released as an update to :rfc:`822`.  This module should be
+   considered :rfc:`2822`\ -conformant, especially in cases where the syntax or
+   semantics have changed since :rfc:`822`.
+
diff --git a/Doc/library/rlcompleter.rst b/Doc/library/rlcompleter.rst
new file mode 100644
index 0000000..b882cb0
--- /dev/null
+++ b/Doc/library/rlcompleter.rst
@@ -0,0 +1,65 @@
+
+:mod:`rlcompleter` --- Completion function for GNU readline
+===========================================================
+
+.. module:: rlcompleter
+   :synopsis: Python identifier completion, suitable for the GNU readline library.
+.. sectionauthor:: Moshe Zadka 
+
+
+The :mod:`rlcompleter` module defines a completion function suitable for the
+:mod:`readline` module by completing valid Python identifiers and keywords.
+
+When this module is imported on a Unix platform with the :mod:`readline` module
+available, an instance of the :class:`Completer` class is automatically created
+and its :meth:`complete` method is set as the :mod:`readline` completer.
+
+Example::
+
+   >>> import rlcompleter
+   >>> import readline
+   >>> readline.parse_and_bind("tab: complete")
+   >>> readline. 
+   readline.__doc__          readline.get_line_buffer  readline.read_init_file
+   readline.__file__         readline.insert_text      readline.set_completer
+   readline.__name__         readline.parse_and_bind
+   >>> readline.
+
+The :mod:`rlcompleter` module is designed for use with Python's interactive
+mode.  A user can add the following lines to his or her initialization file
+(identified by the :envvar:`PYTHONSTARTUP` environment variable) to get
+automatic :kbd:`Tab` completion::
+
+   try:
+       import readline
+   except ImportError:
+       print "Module readline not available."
+   else:
+       import rlcompleter
+       readline.parse_and_bind("tab: complete")
+
+On platforms without :mod:`readline`, the :class:`Completer` class defined by
+this module can still be used for custom purposes.
+
+
+.. _completer-objects:
+
+Completer Objects
+-----------------
+
+Completer objects have the following method:
+
+
+.. method:: Completer.complete(text, state)
+
+   Return the *state*th completion for *text*.
+
+   If called for *text* that doesn't include a period character (``'.'``), it will
+   complete from names currently defined in :mod:`__main__`, :mod:`__builtin__` and
+   keywords (as defined by the :mod:`keyword` module).
+
+   If called for a dotted name, it will try to evaluate anything without obvious
+   side-effects (functions will not be evaluated, but it can generate calls to
+   :meth:`__getattr__`) up to the last part, and find matches for the rest via the
+   :func:`dir` function.
+
diff --git a/Doc/library/robotparser.rst b/Doc/library/robotparser.rst
new file mode 100644
index 0000000..1a66955
--- /dev/null
+++ b/Doc/library/robotparser.rst
@@ -0,0 +1,71 @@
+
+:mod:`robotparser` ---  Parser for robots.txt
+=============================================
+
+.. module:: robotparser
+   :synopsis: Loads a robots.txt file and answers questions about fetchability of other URLs.
+.. sectionauthor:: Skip Montanaro 
+
+
+.. index::
+   single: WWW
+   single: World Wide Web
+   single: URL
+   single: robots.txt
+
+This module provides a single class, :class:`RobotFileParser`, which answers
+questions about whether or not a particular user agent can fetch a URL on the
+Web site that published the :file:`robots.txt` file.  For more details on  the
+structure of :file:`robots.txt` files, see
+http://www.robotstxt.org/wc/norobots.html.
+
+
+.. class:: RobotFileParser()
+
+   This class provides a set of methods to read, parse and answer questions about a
+   single :file:`robots.txt` file.
+
+
+   .. method:: RobotFileParser.set_url(url)
+
+      Sets the URL referring to a :file:`robots.txt` file.
+
+
+   .. method:: RobotFileParser.read()
+
+      Reads the :file:`robots.txt` URL and feeds it to the parser.
+
+
+   .. method:: RobotFileParser.parse(lines)
+
+      Parses the lines argument.
+
+
+   .. method:: RobotFileParser.can_fetch(useragent, url)
+
+      Returns ``True`` if the *useragent* is allowed to fetch the *url* according to
+      the rules contained in the parsed :file:`robots.txt` file.
+
+
+   .. method:: RobotFileParser.mtime()
+
+      Returns the time the ``robots.txt`` file was last fetched.  This is useful for
+      long-running web spiders that need to check for new ``robots.txt`` files
+      periodically.
+
+
+   .. method:: RobotFileParser.modified()
+
+      Sets the time the ``robots.txt`` file was last fetched to the current time.
+
+The following example demonstrates basic use of the RobotFileParser class. ::
+
+   >>> import robotparser
+   >>> rp = robotparser.RobotFileParser()
+   >>> rp.set_url("http://www.musi-cal.com/robots.txt")
+   >>> rp.read()
+   >>> rp.can_fetch("*", "http://www.musi-cal.com/cgi-bin/search?city=San+Francisco")
+   False
+   >>> rp.can_fetch("*", "http://www.musi-cal.com/")
+   True
+
diff --git a/Doc/library/runpy.rst b/Doc/library/runpy.rst
new file mode 100644
index 0000000..8846973
--- /dev/null
+++ b/Doc/library/runpy.rst
@@ -0,0 +1,71 @@
+:mod:`runpy` --- Locating and executing Python modules
+======================================================
+
+.. module:: runpy
+   :synopsis: Locate and run Python modules without importing them first.
+.. moduleauthor:: Nick Coghlan 
+
+
+.. versionadded:: 2.5
+
+The :mod:`runpy` module is used to locate and run Python modules without
+importing them first. Its main use is to implement the :option:`-m` command line
+switch that allows scripts to be located using the Python module namespace
+rather than the filesystem.
+
+When executed as a script, the module effectively operates as follows::
+
+   del sys.argv[0]  # Remove the runpy module from the arguments
+   run_module(sys.argv[0], run_name="__main__", alter_sys=True)
+
+The :mod:`runpy` module provides a single function:
+
+
+.. function:: run_module(mod_name[, init_globals] [, run_name][, alter_sys])
+
+   Execute the code of the specified module and return the resulting module globals
+   dictionary. The module's code is first located using the standard import
+   mechanism (refer to PEP 302 for details) and then executed in a fresh module
+   namespace.
+
+   The optional dictionary argument *init_globals* may be used to pre-populate the
+   globals dictionary before the code is executed. The supplied dictionary will not
+   be modified. If any of the special global variables below are defined in the
+   supplied dictionary, those definitions are overridden by the ``run_module``
+   function.
+
+   The special global variables ``__name__``, ``__file__``, ``__loader__`` and
+   ``__builtins__`` are set in the globals dictionary before the module code is
+   executed.
+
+   ``__name__`` is set to *run_name* if this optional argument is supplied, and the
+   *mod_name* argument otherwise.
+
+   ``__loader__`` is set to the PEP 302 module loader used to retrieve the code for
+   the module (This loader may be a wrapper around the standard import mechanism).
+
+   ``__file__`` is set to the name provided by the module loader. If the loader
+   does not make filename information available, this variable is set to ``None``.
+
+   ``__builtins__`` is automatically initialised with a reference to the top level
+   namespace of the :mod:`__builtin__` module.
+
+   If the argument *alter_sys* is supplied and evaluates to ``True``, then
+   ``sys.argv[0]`` is updated with the value of ``__file__`` and
+   ``sys.modules[__name__]`` is updated with a new module object for the module
+   being executed. Note that neither ``sys.argv[0]`` nor ``sys.modules[__name__]``
+   are restored to their original values before the function returns -- if client
+   code needs these values preserved, it must either save them explicitly or
+   else avoid enabling the automatic alterations to :mod:`sys`.
+
+   Note that this manipulation of :mod:`sys` is not thread-safe. Other threads may
+   see the partially initialised module, as well as the altered list of arguments.
+   It is recommended that the :mod:`sys` module be left alone when invoking this
+   function from threaded code.
+
+
+.. seealso::
+
+   :pep:`338` - Executing modules as scripts
+      PEP written and  implemented by Nick Coghlan.
+
diff --git a/Doc/library/sched.rst b/Doc/library/sched.rst
new file mode 100644
index 0000000..bf3efbf
--- /dev/null
+++ b/Doc/library/sched.rst
@@ -0,0 +1,104 @@
+
+:mod:`sched` --- Event scheduler
+================================
+
+.. module:: sched
+   :synopsis: General purpose event scheduler.
+.. sectionauthor:: Moshe Zadka 
+
+
+.. % LaTeXed and enhanced from comments in file
+
+.. index:: single: event scheduling
+
+The :mod:`sched` module defines a class which implements a general purpose event
+scheduler:
+
+
+.. class:: scheduler(timefunc, delayfunc)
+
+   The :class:`scheduler` class defines a generic interface to scheduling events.
+   It needs two functions to actually deal with the "outside world" --- *timefunc*
+   should be callable without arguments, and return  a number (the "time", in any
+   units whatsoever).  The *delayfunc* function should be callable with one
+   argument, compatible with the output of *timefunc*, and should delay that many
+   time units. *delayfunc* will also be called with the argument ``0`` after each
+   event is run to allow other threads an opportunity to run in multi-threaded
+   applications.
+
+Example::
+
+   >>> import sched, time
+   >>> s=sched.scheduler(time.time, time.sleep)
+   >>> def print_time(): print "From print_time", time.time()
+   ...
+   >>> def print_some_times():
+   ...     print time.time()
+   ...     s.enter(5, 1, print_time, ())
+   ...     s.enter(10, 1, print_time, ())
+   ...     s.run()
+   ...     print time.time()
+   ...
+   >>> print_some_times()
+   930343690.257
+   From print_time 930343695.274
+   From print_time 930343700.273
+   930343700.276
+
+
+.. _scheduler-objects:
+
+Scheduler Objects
+-----------------
+
+:class:`scheduler` instances have the following methods:
+
+
+.. method:: scheduler.enterabs(time, priority, action, argument)
+
+   Schedule a new event. The *time* argument should be a numeric type compatible
+   with the return value of the *timefunc* function passed  to the constructor.
+   Events scheduled for the same *time* will be executed in the order of their
+   *priority*.
+
+   Executing the event means executing ``action(*argument)``.  *argument* must be a
+   sequence holding the parameters for *action*.
+
+   Return value is an event which may be used for later cancellation of the event
+   (see :meth:`cancel`).
+
+
+.. method:: scheduler.enter(delay, priority, action, argument)
+
+   Schedule an event for *delay* more time units. Other then the relative time, the
+   other arguments, the effect and the return value are the same as those for
+   :meth:`enterabs`.
+
+
+.. method:: scheduler.cancel(event)
+
+   Remove the event from the queue. If *event* is not an event currently in the
+   queue, this method will raise a :exc:`RuntimeError`.
+
+
+.. method:: scheduler.empty()
+
+   Return true if the event queue is empty.
+
+
+.. method:: scheduler.run()
+
+   Run all scheduled events. This function will wait  (using the :func:`delayfunc`
+   function passed to the constructor) for the next event, then execute it and so
+   on until there are no more scheduled events.
+
+   Either *action* or *delayfunc* can raise an exception.  In either case, the
+   scheduler will maintain a consistent state and propagate the exception.  If an
+   exception is raised by *action*, the event will not be attempted in future calls
+   to :meth:`run`.
+
+   If a sequence of events takes longer to run than the time available before the
+   next event, the scheduler will simply fall behind.  No events will be dropped;
+   the calling code is responsible for canceling  events which are no longer
+   pertinent.
+
diff --git a/Doc/library/scrolledtext.rst b/Doc/library/scrolledtext.rst
new file mode 100644
index 0000000..85456b9
--- /dev/null
+++ b/Doc/library/scrolledtext.rst
@@ -0,0 +1,32 @@
+:mod:`ScrolledText` --- Scrolled Text Widget
+============================================
+
+.. module:: ScrolledText
+   :platform: Tk
+   :synopsis: Text widget with a vertical scroll bar.
+.. sectionauthor:: Fred L. Drake, Jr. 
+
+
+The :mod:`ScrolledText` module provides a class of the same name which
+implements a basic text widget which has a vertical scroll bar configured to do
+the "right thing."  Using the :class:`ScrolledText` class is a lot easier than
+setting up a text widget and scroll bar directly.  The constructor is the same
+as that of the :class:`Tkinter.Text` class.
+
+The text widget and scrollbar are packed together in a :class:`Frame`, and the
+methods of the :class:`Grid` and :class:`Pack` geometry managers are acquired
+from the :class:`Frame` object.  This allows the :class:`ScrolledText` widget to
+be used directly to achieve most normal geometry management behavior.
+
+Should more specific control be necessary, the following attributes are
+available:
+
+
+.. attribute:: ScrolledText.frame
+
+   The frame which surrounds the text and scroll bar widgets.
+
+
+.. attribute:: ScrolledText.vbar
+
+   The scroll bar widget.
diff --git a/Doc/library/select.rst b/Doc/library/select.rst
new file mode 100644
index 0000000..f68a0da
--- /dev/null
+++ b/Doc/library/select.rst
@@ -0,0 +1,141 @@
+
+:mod:`select` --- Waiting for I/O completion
+============================================
+
+.. module:: select
+   :synopsis: Wait for I/O completion on multiple streams.
+
+
+This module provides access to the :cfunc:`select` and :cfunc:`poll` functions
+available in most operating systems.  Note that on Windows, it only works for
+sockets; on other operating systems, it also works for other file types (in
+particular, on Unix, it works on pipes).  It cannot be used on regular files to
+determine whether a file has grown since it was last read.
+
+The module defines the following:
+
+
+.. exception:: error
+
+   The exception raised when an error occurs.  The accompanying value is a pair
+   containing the numeric error code from :cdata:`errno` and the corresponding
+   string, as would be printed by the C function :cfunc:`perror`.
+
+
+.. function:: poll()
+
+   (Not supported by all operating systems.)  Returns a polling object, which
+   supports registering and unregistering file descriptors, and then polling them
+   for I/O events; see section :ref:`poll-objects` below for the methods supported
+   by polling objects.
+
+
+.. function:: select(iwtd, owtd, ewtd[, timeout])
+
+   This is a straightforward interface to the Unix :cfunc:`select` system call.
+   The first three arguments are sequences of 'waitable objects': either
+   integers representing file descriptors or objects with a parameterless method
+   named :meth:`fileno` returning such an integer.  The three sequences of
+   waitable objects are for input, output and 'exceptional conditions',
+   respectively.  Empty sequences are allowed, but acceptance of three empty
+   sequences is platform-dependent. (It is known to work on Unix but not on
+   Windows.)  The optional *timeout* argument specifies a time-out as a floating
+   point number in seconds.  When the *timeout* argument is omitted the function
+   blocks until at least one file descriptor is ready.  A time-out value of zero
+   specifies a poll and never blocks.
+
+   The return value is a triple of lists of objects that are ready: subsets of the
+   first three arguments.  When the time-out is reached without a file descriptor
+   becoming ready, three empty lists are returned.
+
+   .. index::
+      single: socket() (in module socket)
+      single: popen() (in module os)
+
+   Among the acceptable object types in the sequences are Python file objects (e.g.
+   ``sys.stdin``, or objects returned by :func:`open` or :func:`os.popen`), socket
+   objects returned by :func:`socket.socket`.  You may also define a :dfn:`wrapper`
+   class yourself, as long as it has an appropriate :meth:`fileno` method (that
+   really returns a file descriptor, not just a random integer).
+
+   .. % 
+
+   .. note::
+
+      .. index:: single: WinSock
+
+      File objects on Windows are not acceptable, but sockets are.  On Windows, the
+      underlying :cfunc:`select` function is provided by the WinSock library, and does
+      not handle file descriptors that don't originate from WinSock.
+
+
+.. _poll-objects:
+
+Polling Objects
+---------------
+
+The :cfunc:`poll` system call, supported on most Unix systems, provides better
+scalability for network servers that service many, many clients at the same
+time. :cfunc:`poll` scales better because the system call only requires listing
+the file descriptors of interest, while :cfunc:`select` builds a bitmap, turns
+on bits for the fds of interest, and then afterward the whole bitmap has to be
+linearly scanned again. :cfunc:`select` is O(highest file descriptor), while
+:cfunc:`poll` is O(number of file descriptors).
+
+
+.. method:: poll.register(fd[, eventmask])
+
+   Register a file descriptor with the polling object.  Future calls to the
+   :meth:`poll` method will then check whether the file descriptor has any pending
+   I/O events.  *fd* can be either an integer, or an object with a :meth:`fileno`
+   method that returns an integer.  File objects implement :meth:`fileno`, so they
+   can also be used as the argument.
+
+   *eventmask* is an optional bitmask describing the type of events you want to
+   check for, and can be a combination of the constants :const:`POLLIN`,
+   :const:`POLLPRI`, and :const:`POLLOUT`, described in the table below.  If not
+   specified, the default value used will check for all 3 types of events.
+
+   +-------------------+------------------------------------------+
+   | Constant          | Meaning                                  |
+   +===================+==========================================+
+   | :const:`POLLIN`   | There is data to read                    |
+   +-------------------+------------------------------------------+
+   | :const:`POLLPRI`  | There is urgent data to read             |
+   +-------------------+------------------------------------------+
+   | :const:`POLLOUT`  | Ready for output: writing will not block |
+   +-------------------+------------------------------------------+
+   | :const:`POLLERR`  | Error condition of some sort             |
+   +-------------------+------------------------------------------+
+   | :const:`POLLHUP`  | Hung up                                  |
+   +-------------------+------------------------------------------+
+   | :const:`POLLNVAL` | Invalid request: descriptor not open     |
+   +-------------------+------------------------------------------+
+
+   Registering a file descriptor that's already registered is not an error, and has
+   the same effect as registering the descriptor exactly once.
+
+
+.. method:: poll.unregister(fd)
+
+   Remove a file descriptor being tracked by a polling object.  Just like the
+   :meth:`register` method, *fd* can be an integer or an object with a
+   :meth:`fileno` method that returns an integer.
+
+   Attempting to remove a file descriptor that was never registered causes a
+   :exc:`KeyError` exception to be raised.
+
+
+.. method:: poll.poll([timeout])
+
+   Polls the set of registered file descriptors, and returns a possibly-empty list
+   containing ``(fd, event)`` 2-tuples for the descriptors that have events or
+   errors to report. *fd* is the file descriptor, and *event* is a bitmask with
+   bits set for the reported events for that descriptor --- :const:`POLLIN` for
+   waiting input, :const:`POLLOUT` to indicate that the descriptor can be written
+   to, and so forth. An empty list indicates that the call timed out and no file
+   descriptors had any events to report. If *timeout* is given, it specifies the
+   length of time in milliseconds which the system will wait for events before
+   returning. If *timeout* is omitted, negative, or :const:`None`, the call will
+   block until there is an event for this poll object.
+
diff --git a/Doc/library/sgmllib.rst b/Doc/library/sgmllib.rst
new file mode 100644
index 0000000..c0ef1a2
--- /dev/null
+++ b/Doc/library/sgmllib.rst
@@ -0,0 +1,270 @@
+
+:mod:`sgmllib` --- Simple SGML parser
+=====================================
+
+.. module:: sgmllib
+   :synopsis: Only as much of an SGML parser as needed to parse HTML.
+
+
+.. index:: single: SGML
+
+This module defines a class :class:`SGMLParser` which serves as the basis for
+parsing text files formatted in SGML (Standard Generalized Mark-up Language).
+In fact, it does not provide a full SGML parser --- it only parses SGML insofar
+as it is used by HTML, and the module only exists as a base for the
+:mod:`htmllib` module.  Another HTML parser which supports XHTML and offers a
+somewhat different interface is available in the :mod:`HTMLParser` module.
+
+
+.. class:: SGMLParser()
+
+   The :class:`SGMLParser` class is instantiated without arguments. The parser is
+   hardcoded to recognize the following constructs:
+
+   * Opening and closing tags of the form ```` and
+     ````, respectively.
+
+   * Numeric character references of the form ``&#name;``.
+
+   * Entity references of the form ``&name;``.
+
+   * SGML comments of the form ````.  Note that spaces, tabs, and
+     newlines are allowed between the trailing ``>`` and the immediately preceding
+     ``--``.
+
+A single exception is defined as well:
+
+
+.. exception:: SGMLParseError
+
+   Exception raised by the :class:`SGMLParser` class when it encounters an error
+   while parsing.
+
+   .. versionadded:: 2.1
+
+:class:`SGMLParser` instances have the following methods:
+
+
+.. method:: SGMLParser.reset()
+
+   Reset the instance.  Loses all unprocessed data.  This is called implicitly at
+   instantiation time.
+
+
+.. method:: SGMLParser.setnomoretags()
+
+   Stop processing tags.  Treat all following input as literal input (CDATA).
+   (This is only provided so the HTML tag ```` can be implemented.)
+
+
+.. method:: SGMLParser.setliteral()
+
+   Enter literal mode (CDATA mode).
+
+
+.. method:: SGMLParser.feed(data)
+
+   Feed some text to the parser.  It is processed insofar as it consists of
+   complete elements; incomplete data is buffered until more data is fed or
+   :meth:`close` is called.
+
+
+.. method:: SGMLParser.close()
+
+   Force processing of all buffered data as if it were followed by an end-of-file
+   mark.  This method may be redefined by a derived class to define additional
+   processing at the end of the input, but the redefined version should always call
+   :meth:`close`.
+
+
+.. method:: SGMLParser.get_starttag_text()
+
+   Return the text of the most recently opened start tag.  This should not normally
+   be needed for structured processing, but may be useful in dealing with HTML "as
+   deployed" or for re-generating input with minimal changes (whitespace between
+   attributes can be preserved, etc.).
+
+
+.. method:: SGMLParser.handle_starttag(tag, method, attributes)
+
+   This method is called to handle start tags for which either a :meth:`start_tag`
+   or :meth:`do_tag` method has been defined.  The *tag* argument is the name of
+   the tag converted to lower case, and the *method* argument is the bound method
+   which should be used to support semantic interpretation of the start tag. The
+   *attributes* argument is a list of ``(name, value)`` pairs containing the
+   attributes found inside the tag's ``<>`` brackets.
+
+   The *name* has been translated to lower case. Double quotes and backslashes in
+   the *value* have been interpreted, as well as known character references and
+   known entity references terminated by a semicolon (normally, entity references
+   can be terminated by any non-alphanumerical character, but this would break the
+   very common case of ``<A HREF="url?spam=1&eggs=2">`` when ``eggs`` is a valid
+   entity name).
+
+   For instance, for the tag ``<A HREF="http://www.cwi.nl/">``, this method would
+   be called as ``unknown_starttag('a', [('href', 'http://www.cwi.nl/')])``.  The
+   base implementation simply calls *method* with *attributes* as the only
+   argument.
+
+   .. versionadded:: 2.5
+      Handling of entity and character references within attribute values.
+
+
+.. method:: SGMLParser.handle_endtag(tag, method)
+
+   This method is called to handle endtags for which an :meth:`end_tag` method has
+   been defined.  The *tag* argument is the name of the tag converted to lower
+   case, and the *method* argument is the bound method which should be used to
+   support semantic interpretation of the end tag.  If no :meth:`end_tag` method is
+   defined for the closing element, this handler is not called.  The base
+   implementation simply calls *method*.
+
+
+.. method:: SGMLParser.handle_data(data)
+
+   This method is called to process arbitrary data.  It is intended to be
+   overridden by a derived class; the base class implementation does nothing.
+
+
+.. method:: SGMLParser.handle_charref(ref)
+
+   This method is called to process a character reference of the form ``&#ref;``.
+   The base implementation uses :meth:`convert_charref` to convert the reference to
+   a string.  If that method returns a string, it is passed to :meth:`handle_data`,
+   otherwise ``unknown_charref(ref)`` is called to handle the error.
+
+   .. versionchanged:: 2.5
+      Use :meth:`convert_charref` instead of hard-coding the conversion.
+
+
+.. method:: SGMLParser.convert_charref(ref)
+
+   Convert a character reference to a string, or ``None``.  *ref* is the reference
+   passed in as a string.  In the base implementation, *ref* must be a decimal
+   number in the range 0-255.  It converts the code point found using the
+   :meth:`convert_codepoint` method. If *ref* is invalid or out of range, this
+   method returns ``None``.  This method is called by the default
+   :meth:`handle_charref` implementation and by the attribute value parser.
+
+   .. versionadded:: 2.5
+
+
+.. method:: SGMLParser.convert_codepoint(codepoint)
+
+   Convert a codepoint to a :class:`str` value.  Encodings can be handled here if
+   appropriate, though the rest of :mod:`sgmllib` is oblivious on this matter.
+
+   .. versionadded:: 2.5
+
+
+.. method:: SGMLParser.handle_entityref(ref)
+
+   This method is called to process a general entity reference of the form
+   ``&ref;`` where *ref* is an general entity reference.  It converts *ref* by
+   passing it to :meth:`convert_entityref`.  If a translation is returned, it calls
+   the method :meth:`handle_data` with the translation; otherwise, it calls the
+   method ``unknown_entityref(ref)``. The default :attr:`entitydefs` defines
+   translations for ``&amp;``, ``&apos``, ``&gt;``, ``&lt;``, and ``&quot;``.
+
+   .. versionchanged:: 2.5
+      Use :meth:`convert_entityref` instead of hard-coding the conversion.
+
+
+.. method:: SGMLParser.convert_entityref(ref)
+
+   Convert a named entity reference to a :class:`str` value, or ``None``.  The
+   resulting value will not be parsed.  *ref* will be only the name of the entity.
+   The default implementation looks for *ref* in the instance (or class) variable
+   :attr:`entitydefs` which should be a mapping from entity names to corresponding
+   translations.  If no translation is available for *ref*, this method returns
+   ``None``.  This method is called by the default :meth:`handle_entityref`
+   implementation and by the attribute value parser.
+
+   .. versionadded:: 2.5
+
+
+.. method:: SGMLParser.handle_comment(comment)
+
+   This method is called when a comment is encountered.  The *comment* argument is
+   a string containing the text between the ``<!--`` and ``-->`` delimiters, but
+   not the delimiters themselves.  For example, the comment ``<!--text-->`` will
+   cause this method to be called with the argument ``'text'``.  The default method
+   does nothing.
+
+
+.. method:: SGMLParser.handle_decl(data)
+
+   Method called when an SGML declaration is read by the parser.  In practice, the
+   ``DOCTYPE`` declaration is the only thing observed in HTML, but the parser does
+   not discriminate among different (or broken) declarations.  Internal subsets in
+   a ``DOCTYPE`` declaration are not supported.  The *data* parameter will be the
+   entire contents of the declaration inside the ``<!``...\ ``>`` markup.  The
+   default implementation does nothing.
+
+
+.. method:: SGMLParser.report_unbalanced(tag)
+
+   This method is called when an end tag is found which does not correspond to any
+   open element.
+
+
+.. method:: SGMLParser.unknown_starttag(tag, attributes)
+
+   This method is called to process an unknown start tag.  It is intended to be
+   overridden by a derived class; the base class implementation does nothing.
+
+
+.. method:: SGMLParser.unknown_endtag(tag)
+
+   This method is called to process an unknown end tag.  It is intended to be
+   overridden by a derived class; the base class implementation does nothing.
+
+
+.. method:: SGMLParser.unknown_charref(ref)
+
+   This method is called to process unresolvable numeric character references.
+   Refer to :meth:`handle_charref` to determine what is handled by default.  It is
+   intended to be overridden by a derived class; the base class implementation does
+   nothing.
+
+
+.. method:: SGMLParser.unknown_entityref(ref)
+
+   This method is called to process an unknown entity reference.  It is intended to
+   be overridden by a derived class; the base class implementation does nothing.
+
+Apart from overriding or extending the methods listed above, derived classes may
+also define methods of the following form to define processing of specific tags.
+Tag names in the input stream are case independent; the *tag* occurring in
+method names must be in lower case:
+
+
+.. method:: SGMLParser.start_tag(attributes)
+   :noindex:
+
+   This method is called to process an opening tag *tag*.  It has preference over
+   :meth:`do_tag`.  The *attributes* argument has the same meaning as described for
+   :meth:`handle_starttag` above.
+
+
+.. method:: SGMLParser.do_tag(attributes)
+   :noindex:
+
+   This method is called to process an opening tag *tag*  for which no
+   :meth:`start_tag` method is defined.   The *attributes* argument has the same
+   meaning as described for :meth:`handle_starttag` above.
+
+
+.. method:: SGMLParser.end_tag()
+   :noindex:
+
+   This method is called to process a closing tag *tag*.
+
+Note that the parser maintains a stack of open elements for which no end tag has
+been found yet.  Only tags processed by :meth:`start_tag` are pushed on this
+stack.  Definition of an :meth:`end_tag` method is optional for these tags.  For
+tags processed by :meth:`do_tag` or by :meth:`unknown_tag`, no :meth:`end_tag`
+method must be defined; if defined, it will not be used.  If both
+:meth:`start_tag` and :meth:`do_tag` methods exist for a tag, the
+:meth:`start_tag` method takes precedence.
+
diff --git a/Doc/library/shelve.rst b/Doc/library/shelve.rst
new file mode 100644
index 0000000..1776b7d
--- /dev/null
+++ b/Doc/library/shelve.rst
@@ -0,0 +1,185 @@
+
+:mod:`shelve` --- Python object persistence
+===========================================
+
+.. module:: shelve
+   :synopsis: Python object persistence.
+
+
+.. index:: module: pickle
+
+A "shelf" is a persistent, dictionary-like object.  The difference with "dbm"
+databases is that the values (not the keys!) in a shelf can be essentially
+arbitrary Python objects --- anything that the :mod:`pickle` module can handle.
+This includes most class instances, recursive data types, and objects containing
+lots of shared  sub-objects.  The keys are ordinary strings.
+
+
+.. function:: open(filename[, flag='c'[, protocol=None[, writeback=False]]])
+
+   Open a persistent dictionary.  The filename specified is the base filename for
+   the underlying database.  As a side-effect, an extension may be added to the
+   filename and more than one file may be created.  By default, the underlying
+   database file is opened for reading and writing.  The optional *flag* parameter
+   has the same interpretation as the *flag* parameter of :func:`anydbm.open`.
+
+   By default, version 0 pickles are used to serialize values.  The version of the
+   pickle protocol can be specified with the *protocol* parameter.
+
+   .. versionchanged:: 2.3
+      The *protocol* parameter was added.
+
+   By default, mutations to persistent-dictionary mutable entries are not
+   automatically written back.  If the optional *writeback* parameter is set to
+   *True*, all entries accessed are cached in memory, and written back at close
+   time; this can make it handier to mutate mutable entries in the persistent
+   dictionary, but, if many entries are accessed, it can consume vast amounts of
+   memory for the cache, and it can make the close operation very slow since all
+   accessed entries are written back (there is no way to determine which accessed
+   entries are mutable, nor which ones were actually mutated).
+
+Shelve objects support all methods supported by dictionaries.  This eases the
+transition from dictionary based scripts to those requiring persistent storage.
+
+One additional method is supported:
+
+
+.. method:: Shelf.sync()
+
+   Write back all entries in the cache if the shelf was opened with *writeback* set
+   to *True*. Also empty the cache and synchronize the persistent dictionary on
+   disk, if feasible.  This is called automatically when the shelf is closed with
+   :meth:`close`.
+
+
+Restrictions
+------------
+
+  .. index::
+     module: dbm
+     module: gdbm
+     module: bsddb
+
+* The choice of which database package will be used (such as :mod:`dbm`,
+  :mod:`gdbm` or :mod:`bsddb`) depends on which interface is available.  Therefore
+  it is not safe to open the database directly using :mod:`dbm`.  The database is
+  also (unfortunately) subject to the limitations of :mod:`dbm`, if it is used ---
+  this means that (the pickled representation of) the objects stored in the
+  database should be fairly small, and in rare cases key collisions may cause the
+  database to refuse updates.
+
+* Depending on the implementation, closing a persistent dictionary may or may
+  not be necessary to flush changes to disk.  The :meth:`__del__` method of the
+  :class:`Shelf` class calls the :meth:`close` method, so the programmer generally
+  need not do this explicitly.
+
+* The :mod:`shelve` module does not support *concurrent* read/write access to
+  shelved objects.  (Multiple simultaneous read accesses are safe.)  When a
+  program has a shelf open for writing, no other program should have it open for
+  reading or writing.  Unix file locking can be used to solve this, but this
+  differs across Unix versions and requires knowledge about the database
+  implementation used.
+
+
+.. class:: Shelf(dict[, protocol=None[, writeback=False]])
+
+   A subclass of :class:`UserDict.DictMixin` which stores pickled values in the
+   *dict* object.
+
+   By default, version 0 pickles are used to serialize values.  The version of the
+   pickle protocol can be specified with the *protocol* parameter. See the
+   :mod:`pickle` documentation for a discussion of the pickle protocols.
+
+   .. versionchanged:: 2.3
+      The *protocol* parameter was added.
+
+   If the *writeback* parameter is ``True``, the object will hold a cache of all
+   entries accessed and write them back to the *dict* at sync and close times.
+   This allows natural operations on mutable entries, but can consume much more
+   memory and make sync and close take a long time.
+
+
+.. class:: BsdDbShelf(dict[, protocol=None[, writeback=False]])
+
+   A subclass of :class:`Shelf` which exposes :meth:`first`, :meth:`next`,
+   :meth:`previous`, :meth:`last` and :meth:`set_location` which are available in
+   the :mod:`bsddb` module but not in other database modules.  The *dict* object
+   passed to the constructor must support those methods.  This is generally
+   accomplished by calling one of :func:`bsddb.hashopen`, :func:`bsddb.btopen` or
+   :func:`bsddb.rnopen`.  The optional *protocol* and *writeback* parameters have
+   the same interpretation as for the :class:`Shelf` class.
+
+
+.. class:: DbfilenameShelf(filename[, flag='c'[, protocol=None[, writeback=False]]])
+
+   A subclass of :class:`Shelf` which accepts a *filename* instead of a dict-like
+   object.  The underlying file will be opened using :func:`anydbm.open`.  By
+   default, the file will be created and opened for both read and write.  The
+   optional *flag* parameter has the same interpretation as for the :func:`open`
+   function.  The optional *protocol* and *writeback* parameters have the same
+   interpretation as for the :class:`Shelf` class.
+
+
+Example
+-------
+
+To summarize the interface (``key`` is a string, ``data`` is an arbitrary
+object)::
+
+   import shelve
+
+   d = shelve.open(filename) # open -- file may get suffix added by low-level
+                             # library
+
+   d[key] = data   # store data at key (overwrites old data if
+                   # using an existing key)
+   data = d[key]   # retrieve a COPY of data at key (raise KeyError if no
+                   # such key)
+   del d[key]      # delete data stored at key (raises KeyError
+                   # if no such key)
+   flag = d.has_key(key)   # true if the key exists
+   klist = d.keys() # a list of all existing keys (slow!)
+
+   # as d was opened WITHOUT writeback=True, beware:
+   d['xx'] = range(4)  # this works as expected, but...
+   d['xx'].append(5)   # *this doesn't!* -- d['xx'] is STILL range(4)!!!
+
+   # having opened d without writeback=True, you need to code carefully:
+   temp = d['xx']      # extracts the copy
+   temp.append(5)      # mutates the copy
+   d['xx'] = temp      # stores the copy right back, to persist it
+
+   # or, d=shelve.open(filename,writeback=True) would let you just code
+   # d['xx'].append(5) and have it work as expected, BUT it would also
+   # consume more memory and make the d.close() operation slower.
+
+   d.close()       # close it
+
+
+.. seealso::
+
+   Module :mod:`anydbm`
+      Generic interface to ``dbm``\ -style databases.
+
+   Module :mod:`bsddb`
+      BSD ``db`` database interface.
+
+   Module :mod:`dbhash`
+      Thin layer around the :mod:`bsddb` which provides an :func:`open` function like
+      the other database modules.
+
+   Module :mod:`dbm`
+      Standard Unix database interface.
+
+   Module :mod:`dumbdbm`
+      Portable implementation of the ``dbm`` interface.
+
+   Module :mod:`gdbm`
+      GNU database interface, based on the ``dbm`` interface.
+
+   Module :mod:`pickle`
+      Object serialization used by :mod:`shelve`.
+
+   Module :mod:`cPickle`
+      High-performance version of :mod:`pickle`.
+
diff --git a/Doc/library/shlex.rst b/Doc/library/shlex.rst
new file mode 100644
index 0000000..0ae77c1
--- /dev/null
+++ b/Doc/library/shlex.rst
@@ -0,0 +1,307 @@
+
+:mod:`shlex` --- Simple lexical analysis
+========================================
+
+.. module:: shlex
+   :synopsis: Simple lexical analysis for Unix shell-like languages.
+.. moduleauthor:: Eric S. Raymond <esr@snark.thyrsus.com>
+.. moduleauthor:: Gustavo Niemeyer <niemeyer@conectiva.com>
+.. sectionauthor:: Eric S. Raymond <esr@snark.thyrsus.com>
+.. sectionauthor:: Gustavo Niemeyer <niemeyer@conectiva.com>
+
+
+.. versionadded:: 1.5.2
+
+The :class:`shlex` class makes it easy to write lexical analyzers for simple
+syntaxes resembling that of the Unix shell.  This will often be useful for
+writing minilanguages, (for example, in run control files for Python
+applications) or for parsing quoted strings.
+
+.. note::
+
+   The :mod:`shlex` module currently does not support Unicode input.
+
+The :mod:`shlex` module defines the following functions:
+
+
+.. function:: split(s[, comments[, posix]])
+
+   Split the string *s* using shell-like syntax. If *comments* is :const:`False`
+   (the default), the parsing of comments in the given string will be disabled
+   (setting the :attr:`commenters` member of the :class:`shlex` instance to the
+   empty string).  This function operates in POSIX mode by default, but uses
+   non-POSIX mode if the *posix* argument is false.
+
+   .. versionadded:: 2.3
+
+   .. versionchanged:: 2.6
+      Added the *posix* parameter.
+
+   .. note::
+
+      Since the :func:`split` function instantiates a :class:`shlex` instance, passing
+      ``None`` for *s* will read the string to split from standard input.
+
+The :mod:`shlex` module defines the following class:
+
+
+.. class:: shlex([instream[, infile[, posix]]])
+
+   A :class:`shlex` instance or subclass instance is a lexical analyzer object.
+   The initialization argument, if present, specifies where to read characters
+   from. It must be a file-/stream-like object with :meth:`read` and
+   :meth:`readline` methods, or a string (strings are accepted since Python 2.3).
+   If no argument is given, input will be taken from ``sys.stdin``.  The second
+   optional argument is a filename string, which sets the initial value of the
+   :attr:`infile` member.  If the *instream* argument is omitted or equal to
+   ``sys.stdin``, this second argument defaults to "stdin".  The *posix* argument
+   was introduced in Python 2.3, and defines the operational mode.  When *posix* is
+   not true (default), the :class:`shlex` instance will operate in compatibility
+   mode.  When operating in POSIX mode, :class:`shlex` will try to be as close as
+   possible to the POSIX shell parsing rules.
+
+
+.. seealso::
+
+   Module :mod:`ConfigParser`
+      Parser for configuration files similar to the Windows :file:`.ini` files.
+
+
+.. _shlex-objects:
+
+shlex Objects
+-------------
+
+A :class:`shlex` instance has the following methods:
+
+
+.. method:: shlex.get_token()
+
+   Return a token.  If tokens have been stacked using :meth:`push_token`, pop a
+   token off the stack.  Otherwise, read one from the input stream.  If reading
+   encounters an immediate end-of-file, :attr:`self.eof` is returned (the empty
+   string (``''``) in non-POSIX mode, and ``None`` in POSIX mode).
+
+
+.. method:: shlex.push_token(str)
+
+   Push the argument onto the token stack.
+
+
+.. method:: shlex.read_token()
+
+   Read a raw token.  Ignore the pushback stack, and do not interpret source
+   requests.  (This is not ordinarily a useful entry point, and is documented here
+   only for the sake of completeness.)
+
+
+.. method:: shlex.sourcehook(filename)
+
+   When :class:`shlex` detects a source request (see :attr:`source` below) this
+   method is given the following token as argument, and expected to return a tuple
+   consisting of a filename and an open file-like object.
+
+   Normally, this method first strips any quotes off the argument.  If the result
+   is an absolute pathname, or there was no previous source request in effect, or
+   the previous source was a stream (such as ``sys.stdin``), the result is left
+   alone.  Otherwise, if the result is a relative pathname, the directory part of
+   the name of the file immediately before it on the source inclusion stack is
+   prepended (this behavior is like the way the C preprocessor handles ``#include
+   "file.h"``).
+
+   The result of the manipulations is treated as a filename, and returned as the
+   first component of the tuple, with :func:`open` called on it to yield the second
+   component. (Note: this is the reverse of the order of arguments in instance
+   initialization!)
+
+   This hook is exposed so that you can use it to implement directory search paths,
+   addition of file extensions, and other namespace hacks. There is no
+   corresponding 'close' hook, but a shlex instance will call the :meth:`close`
+   method of the sourced input stream when it returns EOF.
+
+   For more explicit control of source stacking, use the :meth:`push_source` and
+   :meth:`pop_source` methods.
+
+
+.. method:: shlex.push_source(stream[, filename])
+
+   Push an input source stream onto the input stack.  If the filename argument is
+   specified it will later be available for use in error messages.  This is the
+   same method used internally by the :meth:`sourcehook` method.
+
+   .. versionadded:: 2.1
+
+
+.. method:: shlex.pop_source()
+
+   Pop the last-pushed input source from the input stack. This is the same method
+   used internally when the lexer reaches EOF on a stacked input stream.
+
+   .. versionadded:: 2.1
+
+
+.. method:: shlex.error_leader([file[, line]])
+
+   This method generates an error message leader in the format of a Unix C compiler
+   error label; the format is ``'"%s", line %d: '``, where the ``%s`` is replaced
+   with the name of the current source file and the ``%d`` with the current input
+   line number (the optional arguments can be used to override these).
+
+   This convenience is provided to encourage :mod:`shlex` users to generate error
+   messages in the standard, parseable format understood by Emacs and other Unix
+   tools.
+
+Instances of :class:`shlex` subclasses have some public instance variables which
+either control lexical analysis or can be used for debugging:
+
+
+.. attribute:: shlex.commenters
+
+   The string of characters that are recognized as comment beginners. All
+   characters from the comment beginner to end of line are ignored. Includes just
+   ``'#'`` by default.
+
+
+.. attribute:: shlex.wordchars
+
+   The string of characters that will accumulate into multi-character tokens.  By
+   default, includes all ASCII alphanumerics and underscore.
+
+
+.. attribute:: shlex.whitespace
+
+   Characters that will be considered whitespace and skipped.  Whitespace bounds
+   tokens.  By default, includes space, tab, linefeed and carriage-return.
+
+
+.. attribute:: shlex.escape
+
+   Characters that will be considered as escape. This will be only used in POSIX
+   mode, and includes just ``'\'`` by default.
+
+   .. versionadded:: 2.3
+
+
+.. attribute:: shlex.quotes
+
+   Characters that will be considered string quotes.  The token accumulates until
+   the same quote is encountered again (thus, different quote types protect each
+   other as in the shell.)  By default, includes ASCII single and double quotes.
+
+
+.. attribute:: shlex.escapedquotes
+
+   Characters in :attr:`quotes` that will interpret escape characters defined in
+   :attr:`escape`.  This is only used in POSIX mode, and includes just ``'"'`` by
+   default.
+
+   .. versionadded:: 2.3
+
+
+.. attribute:: shlex.whitespace_split
+
+   If ``True``, tokens will only be split in whitespaces. This is useful, for
+   example, for parsing command lines with :class:`shlex`, getting tokens in a
+   similar way to shell arguments.
+
+   .. versionadded:: 2.3
+
+
+.. attribute:: shlex.infile
+
+   The name of the current input file, as initially set at class instantiation time
+   or stacked by later source requests.  It may be useful to examine this when
+   constructing error messages.
+
+
+.. attribute:: shlex.instream
+
+   The input stream from which this :class:`shlex` instance is reading characters.
+
+
+.. attribute:: shlex.source
+
+   This member is ``None`` by default.  If you assign a string to it, that string
+   will be recognized as a lexical-level inclusion request similar to the
+   ``source`` keyword in various shells.  That is, the immediately following token
+   will opened as a filename and input taken from that stream until EOF, at which
+   point the :meth:`close` method of that stream will be called and the input
+   source will again become the original input stream. Source requests may be
+   stacked any number of levels deep.
+
+
+.. attribute:: shlex.debug
+
+   If this member is numeric and ``1`` or more, a :class:`shlex` instance will
+   print verbose progress output on its behavior.  If you need to use this, you can
+   read the module source code to learn the details.
+
+
+.. attribute:: shlex.lineno
+
+   Source line number (count of newlines seen so far plus one).
+
+
+.. attribute:: shlex.token
+
+   The token buffer.  It may be useful to examine this when catching exceptions.
+
+
+.. attribute:: shlex.eof
+
+   Token used to determine end of file. This will be set to the empty string
+   (``''``), in non-POSIX mode, and to ``None`` in POSIX mode.
+
+   .. versionadded:: 2.3
+
+
+.. _shlex-parsing-rules:
+
+Parsing Rules
+-------------
+
+When operating in non-POSIX mode, :class:`shlex` will try to obey to the
+following rules.
+
+* Quote characters are not recognized within words (``Do"Not"Separate`` is
+  parsed as the single word ``Do"Not"Separate``);
+
+* Escape characters are not recognized;
+
+* Enclosing characters in quotes preserve the literal value of all characters
+  within the quotes;
+
+* Closing quotes separate words (``"Do"Separate`` is parsed as ``"Do"`` and
+  ``Separate``);
+
+* If :attr:`whitespace_split` is ``False``, any character not declared to be a
+  word character, whitespace, or a quote will be returned as a single-character
+  token. If it is ``True``, :class:`shlex` will only split words in whitespaces;
+
+* EOF is signaled with an empty string (``''``);
+
+* It's not possible to parse empty strings, even if quoted.
+
+When operating in POSIX mode, :class:`shlex` will try to obey to the following
+parsing rules.
+
+* Quotes are stripped out, and do not separate words (``"Do"Not"Separate"`` is
+  parsed as the single word ``DoNotSeparate``);
+
+* Non-quoted escape characters (e.g. ``'\'``) preserve the literal value of the
+  next character that follows;
+
+* Enclosing characters in quotes which are not part of :attr:`escapedquotes`
+  (e.g. ``"'"``) preserve the literal value of all characters within the quotes;
+
+* Enclosing characters in quotes which are part of :attr:`escapedquotes` (e.g.
+  ``'"'``) preserves the literal value of all characters within the quotes, with
+  the exception of the characters mentioned in :attr:`escape`. The escape
+  characters retain its special meaning only when followed by the quote in use, or
+  the escape character itself. Otherwise the escape character will be considered a
+  normal character.
+
+* EOF is signaled with a :const:`None` value;
+
+* Quoted empty strings (``''``) are allowed;
+
diff --git a/Doc/library/shutil.rst b/Doc/library/shutil.rst
new file mode 100644
index 0000000..ef0758d
--- /dev/null
+++ b/Doc/library/shutil.rst
@@ -0,0 +1,171 @@
+
+:mod:`shutil` --- High-level file operations
+============================================
+
+.. module:: shutil
+   :synopsis: High-level file operations, including copying.
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+.. % partly based on the docstrings
+
+.. index::
+   single: file; copying
+   single: copying files
+
+The :mod:`shutil` module offers a number of high-level operations on files and
+collections of files.  In particular, functions are provided  which support file
+copying and removal.
+
+**Caveat:**  On MacOS, the resource fork and other metadata are not used.  For
+file copies, this means that resources will be lost and  file type and creator
+codes will not be correct.
+
+
+.. function:: copyfile(src, dst)
+
+   Copy the contents of the file named *src* to a file named *dst*.  The
+   destination location must be writable; otherwise,  an :exc:`IOError` exception
+   will be raised. If *dst* already exists, it will be replaced.   Special files
+   such as character or block devices and pipes cannot be copied with this
+   function.  *src* and *dst* are path names given as strings.
+
+
+.. function:: copyfileobj(fsrc, fdst[, length])
+
+   Copy the contents of the file-like object *fsrc* to the file-like object *fdst*.
+   The integer *length*, if given, is the buffer size. In particular, a negative
+   *length* value means to copy the data without looping over the source data in
+   chunks; by default the data is read in chunks to avoid uncontrolled memory
+   consumption. Note that if the current file position of the *fsrc* object is not
+   0, only the contents from the current file position to the end of the file will
+   be copied.
+
+
+.. function:: copymode(src, dst)
+
+   Copy the permission bits from *src* to *dst*.  The file contents, owner, and
+   group are unaffected.  *src* and *dst* are path names given as strings.
+
+
+.. function:: copystat(src, dst)
+
+   Copy the permission bits, last access time, last modification time, and flags
+   from *src* to *dst*.  The file contents, owner, and group are unaffected.  *src*
+   and *dst* are path names given as strings.
+
+
+.. function:: copy(src, dst)
+
+   Copy the file *src* to the file or directory *dst*.  If *dst* is a directory, a
+   file with the same basename as *src*  is created (or overwritten) in the
+   directory specified.  Permission bits are copied.  *src* and *dst* are path
+   names given as strings.
+
+
+.. function:: copy2(src, dst)
+
+   Similar to :func:`copy`, but last access time and last modification time are
+   copied as well.  This is similar to the Unix command :program:`cp -p`.
+
+
+.. function:: copytree(src, dst[, symlinks])
+
+   Recursively copy an entire directory tree rooted at *src*.  The destination
+   directory, named by *dst*, must not already exist; it will be created as well as
+   missing parent directories. Permissions and times of directories are copied with
+   :func:`copystat`, individual files are copied using :func:`copy2`.   If
+   *symlinks* is true, symbolic links in the source tree are represented as
+   symbolic links in the new tree; if false or omitted, the contents of the linked
+   files are copied to the new tree.  If exception(s) occur, an :exc:`Error` is
+   raised with a list of reasons.
+
+   The source code for this should be considered an example rather than  a tool.
+
+   .. versionchanged:: 2.3
+      :exc:`Error` is raised if any exceptions occur during copying, rather than
+      printing a message.
+
+   .. versionchanged:: 2.5
+      Create intermediate directories needed to create *dst*, rather than raising an
+      error. Copy permissions and times of directories using :func:`copystat`.
+
+
+.. function:: rmtree(path[, ignore_errors[, onerror]])
+
+   .. index:: single: directory; deleting
+
+   Delete an entire directory tree (*path* must point to a directory). If
+   *ignore_errors* is true, errors resulting from failed removals will be ignored;
+   if false or omitted, such errors are handled by calling a handler specified by
+   *onerror* or, if that is omitted, they raise an exception.
+
+   If *onerror* is provided, it must be a callable that accepts three parameters:
+   *function*, *path*, and *excinfo*. The first parameter, *function*, is the
+   function which raised the exception; it will be :func:`os.listdir`,
+   :func:`os.remove` or :func:`os.rmdir`.  The second parameter, *path*, will be
+   the path name passed to *function*.  The third parameter, *excinfo*, will be the
+   exception information return by :func:`sys.exc_info`.  Exceptions raised by
+   *onerror* will not be caught.
+
+
+.. function:: move(src, dst)
+
+   Recursively move a file or directory to another location.
+
+   If the destination is on our current filesystem, then simply use rename.
+   Otherwise, copy src to the dst and then remove src.
+
+   .. versionadded:: 2.3
+
+
+.. exception:: Error
+
+   This exception collects exceptions that raised during a mult-file operation. For
+   :func:`copytree`, the exception argument is a list of 3-tuples (*srcname*,
+   *dstname*, *exception*).
+
+   .. versionadded:: 2.3
+
+
+.. _shutil-example:
+
+Example
+-------
+
+This example is the implementation of the :func:`copytree` function, described
+above, with the docstring omitted.  It demonstrates many of the other functions
+provided by this module. ::
+
+   def copytree(src, dst, symlinks=False):
+       names = os.listdir(src)
+       os.makedirs(dst)
+       errors = []
+       for name in names:
+           srcname = os.path.join(src, name)
+           dstname = os.path.join(dst, name)
+           try:
+               if symlinks and os.path.islink(srcname):
+                   linkto = os.readlink(srcname)
+                   os.symlink(linkto, dstname)
+               elif os.path.isdir(srcname):
+                   copytree(srcname, dstname, symlinks)
+               else:
+                   copy2(srcname, dstname)
+               # XXX What about devices, sockets etc.?
+           except (IOError, os.error) as why:
+               errors.append((srcname, dstname, str(why)))
+           # catch the Error from the recursive copytree so that we can
+           # continue with other files
+           except Error as err:
+               errors.extend(err.args[0])
+       try:
+           copystat(src, dst)
+       except WindowsError:
+           # can't copy file access times on Windows
+           pass
+       except OSError as why:
+           errors.extend((src, dst, str(why)))
+       if errors:
+           raise Error, errors
+
diff --git a/Doc/library/signal.rst b/Doc/library/signal.rst
new file mode 100644
index 0000000..54cce53
--- /dev/null
+++ b/Doc/library/signal.rst
@@ -0,0 +1,157 @@
+
+:mod:`signal` --- Set handlers for asynchronous events
+======================================================
+
+.. module:: signal
+   :synopsis: Set handlers for asynchronous events.
+
+
+This module provides mechanisms to use signal handlers in Python. Some general
+rules for working with signals and their handlers:
+
+* A handler for a particular signal, once set, remains installed until it is
+  explicitly reset (Python emulates the BSD style interface regardless of the
+  underlying implementation), with the exception of the handler for
+  :const:`SIGCHLD`, which follows the underlying implementation.
+
+* There is no way to "block" signals temporarily from critical sections (since
+  this is not supported by all Unix flavors).
+
+* Although Python signal handlers are called asynchronously as far as the Python
+  user is concerned, they can only occur between the "atomic" instructions of the
+  Python interpreter.  This means that signals arriving during long calculations
+  implemented purely in C (such as regular expression matches on large bodies of
+  text) may be delayed for an arbitrary amount of time.
+
+* When a signal arrives during an I/O operation, it is possible that the I/O
+  operation raises an exception after the signal handler returns. This is
+  dependent on the underlying Unix system's semantics regarding interrupted system
+  calls.
+
+* Because the C signal handler always returns, it makes little sense to catch
+  synchronous errors like :const:`SIGFPE` or :const:`SIGSEGV`.
+
+* Python installs a small number of signal handlers by default: :const:`SIGPIPE`
+  is ignored (so write errors on pipes and sockets can be reported as ordinary
+  Python exceptions) and :const:`SIGINT` is translated into a
+  :exc:`KeyboardInterrupt` exception.  All of these can be overridden.
+
+* Some care must be taken if both signals and threads are used in the same
+  program.  The fundamental thing to remember in using signals and threads
+  simultaneously is: always perform :func:`signal` operations in the main thread
+  of execution.  Any thread can perform an :func:`alarm`, :func:`getsignal`, or
+  :func:`pause`; only the main thread can set a new signal handler, and the main
+  thread will be the only one to receive signals (this is enforced by the Python
+  :mod:`signal` module, even if the underlying thread implementation supports
+  sending signals to individual threads).  This means that signals can't be used
+  as a means of inter-thread communication.  Use locks instead.
+
+The variables defined in the :mod:`signal` module are:
+
+
+.. data:: SIG_DFL
+
+   This is one of two standard signal handling options; it will simply perform the
+   default function for the signal.  For example, on most systems the default
+   action for :const:`SIGQUIT` is to dump core and exit, while the default action
+   for :const:`SIGCLD` is to simply ignore it.
+
+
+.. data:: SIG_IGN
+
+   This is another standard signal handler, which will simply ignore the given
+   signal.
+
+
+.. data:: SIG*
+
+   All the signal numbers are defined symbolically.  For example, the hangup signal
+   is defined as :const:`signal.SIGHUP`; the variable names are identical to the
+   names used in C programs, as found in ``<signal.h>``. The Unix man page for
+   ':cfunc:`signal`' lists the existing signals (on some systems this is
+   :manpage:`signal(2)`, on others the list is in :manpage:`signal(7)`). Note that
+   not all systems define the same set of signal names; only those names defined by
+   the system are defined by this module.
+
+
+.. data:: NSIG
+
+   One more than the number of the highest signal number.
+
+The :mod:`signal` module defines the following functions:
+
+
+.. function:: alarm(time)
+
+   If *time* is non-zero, this function requests that a :const:`SIGALRM` signal be
+   sent to the process in *time* seconds. Any previously scheduled alarm is
+   canceled (only one alarm can be scheduled at any time).  The returned value is
+   then the number of seconds before any previously set alarm was to have been
+   delivered. If *time* is zero, no alarm is scheduled, and any scheduled alarm is
+   canceled.  If the return value is zero, no alarm is currently scheduled.  (See
+   the Unix man page :manpage:`alarm(2)`.) Availability: Unix.
+
+
+.. function:: getsignal(signalnum)
+
+   Return the current signal handler for the signal *signalnum*. The returned value
+   may be a callable Python object, or one of the special values
+   :const:`signal.SIG_IGN`, :const:`signal.SIG_DFL` or :const:`None`.  Here,
+   :const:`signal.SIG_IGN` means that the signal was previously ignored,
+   :const:`signal.SIG_DFL` means that the default way of handling the signal was
+   previously in use, and ``None`` means that the previous signal handler was not
+   installed from Python.
+
+
+.. function:: pause()
+
+   Cause the process to sleep until a signal is received; the appropriate handler
+   will then be called.  Returns nothing.  Not on Windows. (See the Unix man page
+   :manpage:`signal(2)`.)
+
+
+.. function:: signal(signalnum, handler)
+
+   Set the handler for signal *signalnum* to the function *handler*.  *handler* can
+   be a callable Python object taking two arguments (see below), or one of the
+   special values :const:`signal.SIG_IGN` or :const:`signal.SIG_DFL`.  The previous
+   signal handler will be returned (see the description of :func:`getsignal`
+   above).  (See the Unix man page :manpage:`signal(2)`.)
+
+   When threads are enabled, this function can only be called from the main thread;
+   attempting to call it from other threads will cause a :exc:`ValueError`
+   exception to be raised.
+
+   The *handler* is called with two arguments: the signal number and the current
+   stack frame (``None`` or a frame object; for a description of frame objects, see
+   the reference manual section on the standard type hierarchy or see the attribute
+   descriptions in the :mod:`inspect` module).
+
+
+.. _signal-example:
+
+Example
+-------
+
+Here is a minimal example program. It uses the :func:`alarm` function to limit
+the time spent waiting to open a file; this is useful if the file is for a
+serial device that may not be turned on, which would normally cause the
+:func:`os.open` to hang indefinitely.  The solution is to set a 5-second alarm
+before opening the file; if the operation takes too long, the alarm signal will
+be sent, and the handler raises an exception. ::
+
+   import signal, os
+
+   def handler(signum, frame):
+       print 'Signal handler called with signal', signum
+       raise IOError, "Couldn't open device!"
+
+   # Set the signal handler and a 5-second alarm
+   signal.signal(signal.SIGALRM, handler)
+   signal.alarm(5)
+
+   # This open() may hang indefinitely
+   fd = os.open('/dev/ttyS0', os.O_RDWR)  
+
+   signal.alarm(0)          # Disable the alarm
+
diff --git a/Doc/library/simplehttpserver.rst b/Doc/library/simplehttpserver.rst
new file mode 100644
index 0000000..766253e
--- /dev/null
+++ b/Doc/library/simplehttpserver.rst
@@ -0,0 +1,86 @@
+
+:mod:`SimpleHTTPServer` --- Simple HTTP request handler
+=======================================================
+
+.. module:: SimpleHTTPServer
+   :synopsis: This module provides a basic request handler for HTTP servers.
+.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
+
+
+The :mod:`SimpleHTTPServer` module defines a request-handler class,
+interface-compatible with :class:`BaseHTTPServer.BaseHTTPRequestHandler`, that
+serves files only from a base directory.
+
+The :mod:`SimpleHTTPServer` module defines the following class:
+
+
+.. class:: SimpleHTTPRequestHandler(request, client_address, server)
+
+   This class is used to serve files from the current directory and below, directly
+   mapping the directory structure to HTTP requests.
+
+   A lot of the work, such as parsing the request, is done by the base class
+   :class:`BaseHTTPServer.BaseHTTPRequestHandler`.  This class implements the
+   :func:`do_GET` and :func:`do_HEAD` functions.
+
+The :class:`SimpleHTTPRequestHandler` defines the following member variables:
+
+
+.. attribute:: SimpleHTTPRequestHandler.server_version
+
+   This will be ``"SimpleHTTP/" + __version__``, where ``__version__`` is defined
+   in the module.
+
+
+.. attribute:: SimpleHTTPRequestHandler.extensions_map
+
+   A dictionary mapping suffixes into MIME types. The default is signified by an
+   empty string, and is considered to be ``application/octet-stream``. The mapping
+   is used case-insensitively, and so should contain only lower-cased keys.
+
+The :class:`SimpleHTTPRequestHandler` defines the following methods:
+
+
+.. method:: SimpleHTTPRequestHandler.do_HEAD()
+
+   This method serves the ``'HEAD'`` request type: it sends the headers it would
+   send for the equivalent ``GET`` request. See the :meth:`do_GET` method for a
+   more complete explanation of the possible headers.
+
+
+.. method:: SimpleHTTPRequestHandler.do_GET()
+
+   The request is mapped to a local file by interpreting the request as a path
+   relative to the current working directory.
+
+   If the request was mapped to a directory, the directory is checked for a file
+   named ``index.html`` or ``index.htm`` (in that order). If found, the file's
+   contents are returned; otherwise a directory listing is generated by calling the
+   :meth:`list_directory` method. This method uses :func:`os.listdir` to scan the
+   directory, and returns a ``404`` error response if the :func:`listdir` fails.
+
+   If the request was mapped to a file, it is opened and the contents are returned.
+   Any :exc:`IOError` exception in opening the requested file is mapped to a
+   ``404``, ``'File not found'`` error. Otherwise, the content type is guessed by
+   calling the :meth:`guess_type` method, which in turn uses the *extensions_map*
+   variable.
+
+   A ``'Content-type:'`` header with the guessed content type is output, followed
+   by a ``'Content-Length:'`` header with the file's size and a
+   ``'Last-Modified:'`` header with the file's modification time.
+
+   Then follows a blank line signifying the end of the headers, and then the
+   contents of the file are output. If the file's MIME type starts with ``text/``
+   the file is opened in text mode; otherwise binary mode is used.
+
+   For example usage, see the implementation of the :func:`test` function.
+
+   .. versionadded:: 2.5
+      The ``'Last-Modified'`` header.
+
+
+.. seealso::
+
+   Module :mod:`BaseHTTPServer`
+      Base class implementation for Web server and request handler.
+
diff --git a/Doc/library/simplexmlrpcserver.rst b/Doc/library/simplexmlrpcserver.rst
new file mode 100644
index 0000000..51ce8d8
--- /dev/null
+++ b/Doc/library/simplexmlrpcserver.rst
@@ -0,0 +1,232 @@
+
+:mod:`SimpleXMLRPCServer` --- Basic XML-RPC server
+==================================================
+
+.. module:: SimpleXMLRPCServer
+   :synopsis: Basic XML-RPC server implementation.
+.. moduleauthor:: Brian Quinlan <brianq@activestate.com>
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+.. versionadded:: 2.2
+
+The :mod:`SimpleXMLRPCServer` module provides a basic server framework for
+XML-RPC servers written in Python.  Servers can either be free standing, using
+:class:`SimpleXMLRPCServer`, or embedded in a CGI environment, using
+:class:`CGIXMLRPCRequestHandler`.
+
+
+.. class:: SimpleXMLRPCServer(addr[, requestHandler[, logRequests[, allow_none[, encoding]]]])
+
+   Create a new server instance.  This class provides methods for registration of
+   functions that can be called by the XML-RPC protocol.  The *requestHandler*
+   parameter should be a factory for request handler instances; it defaults to
+   :class:`SimpleXMLRPCRequestHandler`.  The *addr* and *requestHandler* parameters
+   are passed to the :class:`SocketServer.TCPServer` constructor.  If *logRequests*
+   is true (the default), requests will be logged; setting this parameter to false
+   will turn off logging.   The *allow_none* and *encoding* parameters are passed
+   on to  :mod:`xmlrpclib` and control the XML-RPC responses that will be returned
+   from the server. The *bind_and_activate* parameter controls whether
+   :meth:`server_bind` and :meth:`server_activate` are called immediately by the
+   constructor; it defaults to true. Setting it to false allows code to manipulate
+   the *allow_reuse_address* class variable before the address is bound.
+
+   .. versionchanged:: 2.5
+      The *allow_none* and *encoding* parameters were added.
+
+   .. versionchanged:: 2.6
+      The *bind_and_activate* parameter was added.
+
+
+.. class:: CGIXMLRPCRequestHandler([allow_none[, encoding]])
+
+   Create a new instance to handle XML-RPC requests in a CGI environment.  The
+   *allow_none* and *encoding* parameters are passed on to  :mod:`xmlrpclib` and
+   control the XML-RPC responses that will be returned  from the server.
+
+   .. versionadded:: 2.3
+
+   .. versionchanged:: 2.5
+      The *allow_none* and *encoding* parameters were added.
+
+
+.. class:: SimpleXMLRPCRequestHandler()
+
+   Create a new request handler instance.  This request handler supports ``POST``
+   requests and modifies logging so that the *logRequests* parameter to the
+   :class:`SimpleXMLRPCServer` constructor parameter is honored.
+
+
+.. _simple-xmlrpc-servers:
+
+SimpleXMLRPCServer Objects
+--------------------------
+
+The :class:`SimpleXMLRPCServer` class is based on
+:class:`SocketServer.TCPServer` and provides a means of creating simple, stand
+alone XML-RPC servers.
+
+
+.. method:: SimpleXMLRPCServer.register_function(function[, name])
+
+   Register a function that can respond to XML-RPC requests.  If *name* is given,
+   it will be the method name associated with *function*, otherwise
+   ``function.__name__`` will be used.  *name* can be either a normal or Unicode
+   string, and may contain characters not legal in Python identifiers, including
+   the period character.
+
+
+.. method:: SimpleXMLRPCServer.register_instance(instance[, allow_dotted_names])
+
+   Register an object which is used to expose method names which have not been
+   registered using :meth:`register_function`.  If *instance* contains a
+   :meth:`_dispatch` method, it is called with the requested method name and the
+   parameters from the request.  Its API is ``def _dispatch(self, method, params)``
+   (note that *params* does not represent a variable argument list).  If it calls
+   an underlying function to perform its task, that function is called as
+   ``func(*params)``, expanding the parameter list. The return value from
+   :meth:`_dispatch` is returned to the client as the result.  If *instance* does
+   not have a :meth:`_dispatch` method, it is searched for an attribute matching
+   the name of the requested method.
+
+   If the optional *allow_dotted_names* argument is true and the instance does not
+   have a :meth:`_dispatch` method, then if the requested method name contains
+   periods, each component of the method name is searched for individually, with
+   the effect that a simple hierarchical search is performed.  The value found from
+   this search is then called with the parameters from the request, and the return
+   value is passed back to the client.
+
+   .. warning::
+
+      Enabling the *allow_dotted_names* option allows intruders to access your
+      module's global variables and may allow intruders to execute arbitrary code on
+      your machine.  Only use this option on a secure, closed network.
+
+   .. versionchanged:: 2.3.5, 2.4.1
+      *allow_dotted_names* was added to plug a security hole; prior versions are
+      insecure.
+
+
+.. method:: SimpleXMLRPCServer.register_introspection_functions()
+
+   Registers the XML-RPC introspection functions ``system.listMethods``,
+   ``system.methodHelp`` and ``system.methodSignature``.
+
+   .. versionadded:: 2.3
+
+
+.. method:: SimpleXMLRPCServer.register_multicall_functions()
+
+   Registers the XML-RPC multicall function system.multicall.
+
+
+.. attribute:: SimpleXMLRPCServer.rpc_paths
+
+   An attribute value that must be a tuple listing valid path portions of the URL
+   for receiving XML-RPC requests.  Requests posted to other paths will result in a
+   404 "no such page" HTTP error.  If this tuple is empty, all paths will be
+   considered valid. The default value is ``('/', '/RPC2')``.
+
+   .. versionadded:: 2.5
+
+Example::
+
+   from SimpleXMLRPCServer import SimpleXMLRPCServer
+
+   # Create server
+   server = SimpleXMLRPCServer(("localhost", 8000))
+   server.register_introspection_functions()
+
+   # Register pow() function; this will use the value of 
+   # pow.__name__ as the name, which is just 'pow'.
+   server.register_function(pow)
+
+   # Register a function under a different name
+   def adder_function(x,y):
+       return x + y
+   server.register_function(adder_function, 'add')
+
+   # Register an instance; all the methods of the instance are 
+   # published as XML-RPC methods (in this case, just 'div').
+   class MyFuncs:
+       def div(self, x, y): 
+           return x // y
+
+   server.register_instance(MyFuncs())
+
+   # Run the server's main loop
+   server.serve_forever()
+
+The following client code will call the methods made available by  the preceding
+server::
+
+   import xmlrpclib
+
+   s = xmlrpclib.Server('http://localhost:8000')
+   print s.pow(2,3)  # Returns 2**3 = 8
+   print s.add(2,3)  # Returns 5
+   print s.div(5,2)  # Returns 5//2 = 2
+
+   # Print list of available methods
+   print s.system.listMethods()
+
+
+CGIXMLRPCRequestHandler
+-----------------------
+
+The :class:`CGIXMLRPCRequestHandler` class can be used to  handle XML-RPC
+requests sent to Python CGI scripts.
+
+
+.. method:: CGIXMLRPCRequestHandler.register_function(function[, name])
+
+   Register a function that can respond to XML-RPC requests. If  *name* is given,
+   it will be the method name associated with  function, otherwise
+   *function.__name__* will be used. *name* can be either a normal or Unicode
+   string, and may contain  characters not legal in Python identifiers, including
+   the period character.
+
+
+.. method:: CGIXMLRPCRequestHandler.register_instance(instance)
+
+   Register an object which is used to expose method names  which have not been
+   registered using :meth:`register_function`. If  instance contains a
+   :meth:`_dispatch` method, it is called with the  requested method name and the
+   parameters from the  request; the return value is returned to the client as the
+   result. If instance does not have a :meth:`_dispatch` method, it is searched
+   for an attribute matching the name of the requested method; if  the requested
+   method name contains periods, each  component of the method name is searched for
+   individually,  with the effect that a simple hierarchical search is performed.
+   The value found from this search is then called with the  parameters from the
+   request, and the return value is passed  back to the client.
+
+
+.. method:: CGIXMLRPCRequestHandler.register_introspection_functions()
+
+   Register the XML-RPC introspection functions  ``system.listMethods``,
+   ``system.methodHelp`` and  ``system.methodSignature``.
+
+
+.. method:: CGIXMLRPCRequestHandler.register_multicall_functions()
+
+   Register the XML-RPC multicall function ``system.multicall``.
+
+
+.. method:: CGIXMLRPCRequestHandler.handle_request([request_text = None])
+
+   Handle a XML-RPC request. If *request_text* is given, it  should be the POST
+   data provided by the HTTP server,  otherwise the contents of stdin will be used.
+
+Example::
+
+   class MyFuncs:
+       def div(self, x, y) : return x // y
+
+
+   handler = CGIXMLRPCRequestHandler()
+   handler.register_function(pow)
+   handler.register_function(lambda x,y: x+y, 'add')
+   handler.register_introspection_functions()
+   handler.register_instance(MyFuncs())
+   handler.handle_request()
+
diff --git a/Doc/library/site.rst b/Doc/library/site.rst
new file mode 100644
index 0000000..4e54900
--- /dev/null
+++ b/Doc/library/site.rst
@@ -0,0 +1,87 @@
+
+:mod:`site` --- Site-specific configuration hook
+================================================
+
+.. module:: site
+   :synopsis: A standard way to reference site-specific modules.
+
+
+**This module is automatically imported during initialization.** The automatic
+import can be suppressed using the interpreter's :option:`-S` option.
+
+.. index:: triple: module; search; path
+
+Importing this module will append site-specific paths to the module search path.
+
+.. index::
+   pair: site-python; directory
+   pair: site-packages; directory
+
+It starts by constructing up to four directories from a head and a tail part.
+For the head part, it uses ``sys.prefix`` and ``sys.exec_prefix``; empty heads
+are skipped.  For the tail part, it uses the empty string and then
+:file:`lib/site-packages` (on Windows) or
+:file:`lib/python|version|/site-packages` and then :file:`lib/site-python` (on
+Unix and Macintosh).  For each of the distinct head-tail combinations, it sees
+if it refers to an existing directory, and if so, adds it to ``sys.path`` and
+also inspects the newly added path for configuration files.
+
+A path configuration file is a file whose name has the form :file:`package.pth`
+and exists in one of the four directories mentioned above; its contents are
+additional items (one per line) to be added to ``sys.path``.  Non-existing items
+are never added to ``sys.path``, but no check is made that the item refers to a
+directory (rather than a file).  No item is added to ``sys.path`` more than
+once.  Blank lines and lines beginning with ``#`` are skipped.  Lines starting
+with ``import`` (followed by space or tab) are executed.
+
+.. versionchanged:: 2.6
+   A space or tab is now required after the import keyword.
+
+.. index::
+   single: package
+   triple: path; configuration; file
+
+For example, suppose ``sys.prefix`` and ``sys.exec_prefix`` are set to
+:file:`/usr/local`.  The Python X.Y library is then installed in
+:file:`/usr/local/lib/python{X.Y}` (where only the first three characters of
+``sys.version`` are used to form the installation path name).  Suppose this has
+a subdirectory :file:`/usr/local/lib/python{X.Y}/site-packages` with three
+subsubdirectories, :file:`foo`, :file:`bar` and :file:`spam`, and two path
+configuration files, :file:`foo.pth` and :file:`bar.pth`.  Assume
+:file:`foo.pth` contains the following::
+
+   # foo package configuration
+
+   foo
+   bar
+   bletch
+
+and :file:`bar.pth` contains::
+
+   # bar package configuration
+
+   bar
+
+Then the following directories are added to ``sys.path``, in this order::
+
+   /usr/local/lib/python2.3/site-packages/bar
+   /usr/local/lib/python2.3/site-packages/foo
+
+Note that :file:`bletch` is omitted because it doesn't exist; the :file:`bar`
+directory precedes the :file:`foo` directory because :file:`bar.pth` comes
+alphabetically before :file:`foo.pth`; and :file:`spam` is omitted because it is
+not mentioned in either path configuration file.
+
+.. index:: module: sitecustomize
+
+After these path manipulations, an attempt is made to import a module named
+:mod:`sitecustomize`, which can perform arbitrary site-specific customizations.
+If this import fails with an :exc:`ImportError` exception, it is silently
+ignored.
+
+.. index:: module: sitecustomize
+
+Note that for some non-Unix systems, ``sys.prefix`` and ``sys.exec_prefix`` are
+empty, and the path manipulations are skipped; however the import of
+:mod:`sitecustomize` is still attempted.
+
diff --git a/Doc/library/smtpd.rst b/Doc/library/smtpd.rst
new file mode 100644
index 0000000..8927a64
--- /dev/null
+++ b/Doc/library/smtpd.rst
@@ -0,0 +1,72 @@
+:mod:`smtpd` --- SMTP Server
+============================
+
+.. module:: smtpd
+   :synopsis: A SMTP server implementation in Python.
+
+.. moduleauthor:: Barry Warsaw <barry@zope.com>
+.. sectionauthor:: Moshe Zadka <moshez@moshez.org>
+
+
+
+
+This module offers several classes to implement SMTP servers.  One is a generic
+do-nothing implementation, which can be overridden, while the other two offer
+specific mail-sending strategies.
+
+
+SMTPServer Objects
+------------------
+
+
+.. class:: SMTPServer(localaddr, remoteaddr)
+
+   Create a new :class:`SMTPServer` object, which binds to local address
+   *localaddr*.  It will treat *remoteaddr* as an upstream SMTP relayer.  It
+   inherits from :class:`asyncore.dispatcher`, and so will insert itself into
+   :mod:`asyncore`'s event loop on instantiation.
+
+
+.. method:: SMTPServer.process_message(peer, mailfrom, rcpttos, data)
+
+   Raise :exc:`NotImplementedError` exception. Override this in subclasses to do
+   something useful with this message. Whatever was passed in the constructor as
+   *remoteaddr* will be available as the :attr:`_remoteaddr` attribute. *peer* is
+   the remote host's address, *mailfrom* is the envelope originator, *rcpttos* are
+   the envelope recipients and *data* is a string containing the contents of the
+   e-mail (which should be in :rfc:`2822` format).
+
+
+DebuggingServer Objects
+-----------------------
+
+
+.. class:: DebuggingServer(localaddr, remoteaddr)
+
+   Create a new debugging server.  Arguments are as per :class:`SMTPServer`.
+   Messages will be discarded, and printed on stdout.
+
+
+PureProxy Objects
+-----------------
+
+
+.. class:: PureProxy(localaddr, remoteaddr)
+
+   Create a new pure proxy server. Arguments are as per :class:`SMTPServer`.
+   Everything will be relayed to *remoteaddr*.  Note that running this has a good
+   chance to make you into an open relay, so please be careful.
+
+
+MailmanProxy Objects
+--------------------
+
+
+.. class:: MailmanProxy(localaddr, remoteaddr)
+
+   Create a new pure proxy server. Arguments are as per :class:`SMTPServer`.
+   Everything will be relayed to *remoteaddr*, unless local mailman configurations
+   knows about an address, in which case it will be handled via mailman.  Note that
+   running this has a good chance to make you into an open relay, so please be
+   careful.
+
diff --git a/Doc/library/smtplib.rst b/Doc/library/smtplib.rst
new file mode 100644
index 0000000..fd898ca
--- /dev/null
+++ b/Doc/library/smtplib.rst
@@ -0,0 +1,347 @@
+
+:mod:`smtplib` --- SMTP protocol client
+=======================================
+
+.. module:: smtplib
+   :synopsis: SMTP protocol client (requires sockets).
+.. sectionauthor:: Eric S. Raymond <esr@snark.thyrsus.com>
+
+
+.. index::
+   pair: SMTP; protocol
+   single: Simple Mail Transfer Protocol
+
+The :mod:`smtplib` module defines an SMTP client session object that can be used
+to send mail to any Internet machine with an SMTP or ESMTP listener daemon.  For
+details of SMTP and ESMTP operation, consult :rfc:`821` (Simple Mail Transfer
+Protocol) and :rfc:`1869` (SMTP Service Extensions).
+
+
+.. class:: SMTP([host[, port[, local_hostname[, timeout]]]])
+
+   A :class:`SMTP` instance encapsulates an SMTP connection.  It has methods that
+   support a full repertoire of SMTP and ESMTP operations. If the optional host and
+   port parameters are given, the SMTP :meth:`connect` method is called with those
+   parameters during initialization.  An :exc:`SMTPConnectError` is raised if the
+   specified host doesn't respond correctly. The optional *timeout* parameter
+   specifies a timeout in seconds for the connection attempt (if not specified, or
+   passed as None, the global default timeout setting will be used).
+
+   For normal use, you should only require the initialization/connect,
+   :meth:`sendmail`, and :meth:`quit` methods.  An example is included below.
+
+   .. versionchanged:: 2.6
+      *timeout* was added.
+
+
+.. class:: SMTP_SSL([host[, port[, local_hostname[, keyfile[, certfile[, timeout]]]]]])
+
+   A :class:`SMTP_SSL` instance behaves exactly the same as instances of
+   :class:`SMTP`. :class:`SMTP_SSL` should be used for situations where SSL is
+   required from  the beginning of the connection and using :meth:`starttls` is not
+   appropriate. If *host* is not specified, the local host is used. If *port* is
+   omitted, the standard SMTP-over-SSL port (465) is used. *keyfile* and *certfile*
+   are also optional, and can contain a PEM formatted private key and certificate
+   chain file for the SSL connection. The optional *timeout* parameter specifies a
+   timeout in seconds for the connection attempt (if not specified, or passed as
+   None, the global default timeout setting will be used).
+
+   .. versionchanged:: 2.6
+      *timeout* was added.
+
+
+.. class:: LMTP([host[, port[, local_hostname]]])
+
+   The LMTP protocol, which is very similar to ESMTP, is heavily based on the
+   standard SMTP client. It's common to use Unix sockets for LMTP, so our connect()
+   method must support that as well as a regular host:port server. To specify a
+   Unix socket, you must use an absolute path for *host*, starting with a '/'.
+
+   Authentication is supported, using the regular SMTP mechanism. When using a Unix
+   socket, LMTP generally don't support or require any authentication, but your
+   mileage might vary.
+
+   .. versionadded:: 2.6
+
+A nice selection of exceptions is defined as well:
+
+
+.. exception:: SMTPException
+
+   Base exception class for all exceptions raised by this module.
+
+
+.. exception:: SMTPServerDisconnected
+
+   This exception is raised when the server unexpectedly disconnects, or when an
+   attempt is made to use the :class:`SMTP` instance before connecting it to a
+   server.
+
+
+.. exception:: SMTPResponseException
+
+   Base class for all exceptions that include an SMTP error code. These exceptions
+   are generated in some instances when the SMTP server returns an error code.  The
+   error code is stored in the :attr:`smtp_code` attribute of the error, and the
+   :attr:`smtp_error` attribute is set to the error message.
+
+
+.. exception:: SMTPSenderRefused
+
+   Sender address refused.  In addition to the attributes set by on all
+   :exc:`SMTPResponseException` exceptions, this sets 'sender' to the string that
+   the SMTP server refused.
+
+
+.. exception:: SMTPRecipientsRefused
+
+   All recipient addresses refused.  The errors for each recipient are accessible
+   through the attribute :attr:`recipients`, which is a dictionary of exactly the
+   same sort as :meth:`SMTP.sendmail` returns.
+
+
+.. exception:: SMTPDataError
+
+   The SMTP server refused to accept the message data.
+
+
+.. exception:: SMTPConnectError
+
+   Error occurred during establishment of a connection  with the server.
+
+
+.. exception:: SMTPHeloError
+
+   The server refused our ``HELO`` message.
+
+
+.. exception:: SMTPAuthenticationError
+
+   SMTP authentication went wrong.  Most probably the server didn't accept the
+   username/password combination provided.
+
+
+.. seealso::
+
+   :rfc:`821` - Simple Mail Transfer Protocol
+      Protocol definition for SMTP.  This document covers the model, operating
+      procedure, and protocol details for SMTP.
+
+   :rfc:`1869` - SMTP Service Extensions
+      Definition of the ESMTP extensions for SMTP.  This describes a framework for
+      extending SMTP with new commands, supporting dynamic discovery of the commands
+      provided by the server, and defines a few additional commands.
+
+
+.. _smtp-objects:
+
+SMTP Objects
+------------
+
+An :class:`SMTP` instance has the following methods:
+
+
+.. method:: SMTP.set_debuglevel(level)
+
+   Set the debug output level.  A true value for *level* results in debug messages
+   for connection and for all messages sent to and received from the server.
+
+
+.. method:: SMTP.connect([host[, port]])
+
+   Connect to a host on a given port.  The defaults are to connect to the local
+   host at the standard SMTP port (25). If the hostname ends with a colon (``':'``)
+   followed by a number, that suffix will be stripped off and the number
+   interpreted as the port number to use. This method is automatically invoked by
+   the constructor if a host is specified during instantiation.
+
+
+.. method:: SMTP.docmd(cmd, [, argstring])
+
+   Send a command *cmd* to the server.  The optional argument *argstring* is simply
+   concatenated to the command, separated by a space.
+
+   This returns a 2-tuple composed of a numeric response code and the actual
+   response line (multiline responses are joined into one long line.)
+
+   In normal operation it should not be necessary to call this method explicitly.
+   It is used to implement other methods and may be useful for testing private
+   extensions.
+
+   If the connection to the server is lost while waiting for the reply,
+   :exc:`SMTPServerDisconnected` will be raised.
+
+
+.. method:: SMTP.helo([hostname])
+
+   Identify yourself to the SMTP server using ``HELO``.  The hostname argument
+   defaults to the fully qualified domain name of the local host.
+
+   In normal operation it should not be necessary to call this method explicitly.
+   It will be implicitly called by the :meth:`sendmail` when necessary.
+
+
+.. method:: SMTP.ehlo([hostname])
+
+   Identify yourself to an ESMTP server using ``EHLO``.  The hostname argument
+   defaults to the fully qualified domain name of the local host.  Examine the
+   response for ESMTP option and store them for use by :meth:`has_extn`.
+
+   Unless you wish to use :meth:`has_extn` before sending mail, it should not be
+   necessary to call this method explicitly.  It will be implicitly called by
+   :meth:`sendmail` when necessary.
+
+
+.. method:: SMTP.has_extn(name)
+
+   Return :const:`True` if *name* is in the set of SMTP service extensions returned
+   by the server, :const:`False` otherwise. Case is ignored.
+
+
+.. method:: SMTP.verify(address)
+
+   Check the validity of an address on this server using SMTP ``VRFY``. Returns a
+   tuple consisting of code 250 and a full :rfc:`822` address (including human
+   name) if the user address is valid. Otherwise returns an SMTP error code of 400
+   or greater and an error string.
+
+   .. note::
+
+      Many sites disable SMTP ``VRFY`` in order to foil spammers.
+
+
+.. method:: SMTP.login(user, password)
+
+   Log in on an SMTP server that requires authentication. The arguments are the
+   username and the password to authenticate with. If there has been no previous
+   ``EHLO`` or ``HELO`` command this session, this method tries ESMTP ``EHLO``
+   first. This method will return normally if the authentication was successful, or
+   may raise the following exceptions:
+
+   :exc:`SMTPHeloError`
+      The server didn't reply properly to the ``HELO`` greeting.
+
+   :exc:`SMTPAuthenticationError`
+      The server didn't accept the username/password combination.
+
+   :exc:`SMTPException`
+      No suitable authentication method was found.
+
+
+.. method:: SMTP.starttls([keyfile[, certfile]])
+
+   Put the SMTP connection in TLS (Transport Layer Security) mode.  All SMTP
+   commands that follow will be encrypted.  You should then call :meth:`ehlo`
+   again.
+
+   If *keyfile* and *certfile* are provided, these are passed to the :mod:`socket`
+   module's :func:`ssl` function.
+
+
+.. method:: SMTP.sendmail(from_addr, to_addrs, msg[, mail_options, rcpt_options])
+
+   Send mail.  The required arguments are an :rfc:`822` from-address string, a list
+   of :rfc:`822` to-address strings (a bare string will be treated as a list with 1
+   address), and a message string.  The caller may pass a list of ESMTP options
+   (such as ``8bitmime``) to be used in ``MAIL FROM`` commands as *mail_options*.
+   ESMTP options (such as ``DSN`` commands) that should be used with all ``RCPT``
+   commands can be passed as *rcpt_options*.  (If you need to use different ESMTP
+   options to different recipients you have to use the low-level methods such as
+   :meth:`mail`, :meth:`rcpt` and :meth:`data` to send the message.)
+
+   .. note::
+
+      The *from_addr* and *to_addrs* parameters are used to construct the message
+      envelope used by the transport agents. The :class:`SMTP` does not modify the
+      message headers in any way.
+
+   If there has been no previous ``EHLO`` or ``HELO`` command this session, this
+   method tries ESMTP ``EHLO`` first. If the server does ESMTP, message size and
+   each of the specified options will be passed to it (if the option is in the
+   feature set the server advertises).  If ``EHLO`` fails, ``HELO`` will be tried
+   and ESMTP options suppressed.
+
+   This method will return normally if the mail is accepted for at least one
+   recipient. Otherwise it will throw an exception.  That is, if this method does
+   not throw an exception, then someone should get your mail. If this method does
+   not throw an exception, it returns a dictionary, with one entry for each
+   recipient that was refused.  Each entry contains a tuple of the SMTP error code
+   and the accompanying error message sent by the server.
+
+   This method may raise the following exceptions:
+
+   :exc:`SMTPRecipientsRefused`
+      All recipients were refused.  Nobody got the mail.  The :attr:`recipients`
+      attribute of the exception object is a dictionary with information about the
+      refused recipients (like the one returned when at least one recipient was
+      accepted).
+
+   :exc:`SMTPHeloError`
+      The server didn't reply properly to the ``HELO`` greeting.
+
+   :exc:`SMTPSenderRefused`
+      The server didn't accept the *from_addr*.
+
+   :exc:`SMTPDataError`
+      The server replied with an unexpected error code (other than a refusal of a
+      recipient).
+
+   Unless otherwise noted, the connection will be open even after an exception is
+   raised.
+
+
+.. method:: SMTP.quit()
+
+   Terminate the SMTP session and close the connection.
+
+Low-level methods corresponding to the standard SMTP/ESMTP commands ``HELP``,
+``RSET``, ``NOOP``, ``MAIL``, ``RCPT``, and ``DATA`` are also supported.
+Normally these do not need to be called directly, so they are not documented
+here.  For details, consult the module code.
+
+
+.. _smtp-example:
+
+SMTP Example
+------------
+
+This example prompts the user for addresses needed in the message envelope ('To'
+and 'From' addresses), and the message to be delivered.  Note that the headers
+to be included with the message must be included in the message as entered; this
+example doesn't do any processing of the :rfc:`822` headers.  In particular, the
+'To' and 'From' addresses must be included in the message headers explicitly. ::
+
+   import smtplib
+
+   def raw_input(prompt):
+       import sys
+       sys.stdout.write(prompt)
+       sys.stdout.flush()
+       return sys.stdin.readline()
+
+   def prompt(prompt):
+       return raw_input(prompt).strip()
+
+   fromaddr = prompt("From: ")
+   toaddrs  = prompt("To: ").split()
+   print "Enter message, end with ^D (Unix) or ^Z (Windows):"
+
+   # Add the From: and To: headers at the start!
+   msg = ("From: %s\r\nTo: %s\r\n\r\n"
+          % (fromaddr, ", ".join(toaddrs)))
+   while 1:
+       try:
+           line = raw_input()
+       except EOFError:
+           break
+       if not line:
+           break
+       msg = msg + line
+
+   print "Message length is " + repr(len(msg))
+
+   server = smtplib.SMTP('localhost')
+   server.set_debuglevel(1)
+   server.sendmail(fromaddr, toaddrs, msg)
+   server.quit()
+
diff --git a/Doc/library/sndhdr.rst b/Doc/library/sndhdr.rst
new file mode 100644
index 0000000..90d71a9
--- /dev/null
+++ b/Doc/library/sndhdr.rst
@@ -0,0 +1,42 @@
+
+:mod:`sndhdr` --- Determine type of sound file
+==============================================
+
+.. module:: sndhdr
+   :synopsis: Determine type of a sound file.
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+.. % Based on comments in the module source file.
+
+.. index::
+   single: A-LAW
+   single: u-LAW
+
+The :mod:`sndhdr` provides utility functions which attempt to determine the type
+of sound data which is in a file.  When these functions are able to determine
+what type of sound data is stored in a file, they return a tuple ``(type,
+sampling_rate, channels, frames, bits_per_sample)``.  The value for *type*
+indicates the data type and will be one of the strings ``'aifc'``, ``'aiff'``,
+``'au'``, ``'hcom'``, ``'sndr'``, ``'sndt'``, ``'voc'``, ``'wav'``, ``'8svx'``,
+``'sb'``, ``'ub'``, or ``'ul'``.  The *sampling_rate* will be either the actual
+value or ``0`` if unknown or difficult to decode.  Similarly, *channels* will be
+either the number of channels or ``0`` if it cannot be determined or if the
+value is difficult to decode.  The value for *frames* will be either the number
+of frames or ``-1``.  The last item in the tuple, *bits_per_sample*, will either
+be the sample size in bits or ``'A'`` for A-LAW or ``'U'`` for u-LAW.
+
+
+.. function:: what(filename)
+
+   Determines the type of sound data stored in the file *filename* using
+   :func:`whathdr`.  If it succeeds, returns a tuple as described above, otherwise
+   ``None`` is returned.
+
+
+.. function:: whathdr(filename)
+
+   Determines the type of sound data stored in a file based on the file  header.
+   The name of the file is given by *filename*.  This function returns a tuple as
+   described above on success, or ``None``.
+
diff --git a/Doc/library/socket.rst b/Doc/library/socket.rst
new file mode 100644
index 0000000..0ec4461
--- /dev/null
+++ b/Doc/library/socket.rst
@@ -0,0 +1,941 @@
+
+:mod:`socket` --- Low-level networking interface
+================================================
+
+.. module:: socket
+   :synopsis: Low-level networking interface.
+
+
+This module provides access to the BSD *socket* interface. It is available on
+all modern Unix systems, Windows, MacOS, BeOS, OS/2, and probably additional
+platforms.
+
+.. note::
+
+   Some behavior may be platform dependent, since calls are made to the operating
+   system socket APIs.
+
+For an introduction to socket programming (in C), see the following papers: An
+Introductory 4.3BSD Interprocess Communication Tutorial, by Stuart Sechrest and
+An Advanced 4.3BSD Interprocess Communication Tutorial, by Samuel J.  Leffler et
+al, both in the UNIX Programmer's Manual, Supplementary Documents 1 (sections
+PS1:7 and PS1:8).  The platform-specific reference material for the various
+socket-related system calls are also a valuable source of information on the
+details of socket semantics.  For Unix, refer to the manual pages; for Windows,
+see the WinSock (or Winsock 2) specification. For IPv6-ready APIs, readers may
+want to refer to :rfc:`2553` titled Basic Socket Interface Extensions for IPv6.
+
+.. index:: object: socket
+
+The Python interface is a straightforward transliteration of the Unix system
+call and library interface for sockets to Python's object-oriented style: the
+:func:`socket` function returns a :dfn:`socket object` whose methods implement
+the various socket system calls.  Parameter types are somewhat higher-level than
+in the C interface: as with :meth:`read` and :meth:`write` operations on Python
+files, buffer allocation on receive operations is automatic, and buffer length
+is implicit on send operations.
+
+Socket addresses are represented as follows: A single string is used for the
+:const:`AF_UNIX` address family. A pair ``(host, port)`` is used for the
+:const:`AF_INET` address family, where *host* is a string representing either a
+hostname in Internet domain notation like ``'daring.cwi.nl'`` or an IPv4 address
+like ``'100.50.200.5'``, and *port* is an integral port number. For
+:const:`AF_INET6` address family, a four-tuple ``(host, port, flowinfo,
+scopeid)`` is used, where *flowinfo* and *scopeid* represents ``sin6_flowinfo``
+and ``sin6_scope_id`` member in :const:`struct sockaddr_in6` in C. For
+:mod:`socket` module methods, *flowinfo* and *scopeid* can be omitted just for
+backward compatibility. Note, however, omission of *scopeid* can cause problems
+in manipulating scoped IPv6 addresses. Other address families are currently not
+supported. The address format required by a particular socket object is
+automatically selected based on the address family specified when the socket
+object was created.
+
+For IPv4 addresses, two special forms are accepted instead of a host address:
+the empty string represents :const:`INADDR_ANY`, and the string
+``'<broadcast>'`` represents :const:`INADDR_BROADCAST`. The behavior is not
+available for IPv6 for backward compatibility, therefore, you may want to avoid
+these if you intend to support IPv6 with your Python programs.
+
+If you use a hostname in the *host* portion of IPv4/v6 socket address, the
+program may show a nondeterministic behavior, as Python uses the first address
+returned from the DNS resolution.  The socket address will be resolved
+differently into an actual IPv4/v6 address, depending on the results from DNS
+resolution and/or the host configuration.  For deterministic behavior use a
+numeric address in *host* portion.
+
+.. versionadded:: 2.5
+   AF_NETLINK sockets are represented as  pairs ``pid, groups``.
+
+All errors raise exceptions.  The normal exceptions for invalid argument types
+and out-of-memory conditions can be raised; errors related to socket or address
+semantics raise the error :exc:`socket.error`.
+
+Non-blocking mode is supported through :meth:`setblocking`.  A generalization of
+this based on timeouts is supported through :meth:`settimeout`.
+
+The module :mod:`socket` exports the following constants and functions:
+
+
+.. exception:: error
+
+   .. index:: module: errno
+
+   This exception is raised for socket-related errors. The accompanying value is
+   either a string telling what went wrong or a pair ``(errno, string)``
+   representing an error returned by a system call, similar to the value
+   accompanying :exc:`os.error`. See the module :mod:`errno`, which contains names
+   for the error codes defined by the underlying operating system.
+
+
+.. exception:: herror
+
+   This exception is raised for address-related errors, i.e. for functions that use
+   *h_errno* in the C API, including :func:`gethostbyname_ex` and
+   :func:`gethostbyaddr`.
+
+   The accompanying value is a pair ``(h_errno, string)`` representing an error
+   returned by a library call. *string* represents the description of *h_errno*, as
+   returned by the :cfunc:`hstrerror` C function.
+
+
+.. exception:: gaierror
+
+   This exception is raised for address-related errors, for :func:`getaddrinfo` and
+   :func:`getnameinfo`. The accompanying value is a pair ``(error, string)``
+   representing an error returned by a library call. *string* represents the
+   description of *error*, as returned by the :cfunc:`gai_strerror` C function. The
+   *error* value will match one of the :const:`EAI_\*` constants defined in this
+   module.
+
+
+.. exception:: timeout
+
+   This exception is raised when a timeout occurs on a socket which has had
+   timeouts enabled via a prior call to :meth:`settimeout`.  The accompanying value
+   is a string whose value is currently always "timed out".
+
+   .. versionadded:: 2.3
+
+
+.. data:: AF_UNIX
+          AF_INET
+          AF_INET6
+
+   These constants represent the address (and protocol) families, used for the
+   first argument to :func:`socket`.  If the :const:`AF_UNIX` constant is not
+   defined then this protocol is unsupported.
+
+
+.. data:: SOCK_STREAM
+          SOCK_DGRAM
+          SOCK_RAW
+          SOCK_RDM
+          SOCK_SEQPACKET
+
+   These constants represent the socket types, used for the second argument to
+   :func:`socket`. (Only :const:`SOCK_STREAM` and :const:`SOCK_DGRAM` appear to be
+   generally useful.)
+
+
+.. data:: SO_*
+          SOMAXCONN
+          MSG_*
+          SOL_*
+          IPPROTO_*
+          IPPORT_*
+          INADDR_*
+          IP_*
+          IPV6_*
+          EAI_*
+          AI_*
+          NI_*
+          TCP_*
+
+   Many constants of these forms, documented in the Unix documentation on sockets
+   and/or the IP protocol, are also defined in the socket module. They are
+   generally used in arguments to the :meth:`setsockopt` and :meth:`getsockopt`
+   methods of socket objects.  In most cases, only those symbols that are defined
+   in the Unix header files are defined; for a few symbols, default values are
+   provided.
+
+
+.. data:: has_ipv6
+
+   This constant contains a boolean value which indicates if IPv6 is supported on
+   this platform.
+
+   .. versionadded:: 2.3
+
+
+.. function:: create_connection(address[, timeout])
+
+   Connects to the *address* received (as usual, a ``(host, port)`` pair), with an
+   optional timeout for the connection.  Specially useful for higher-level
+   protocols, it is not normally used directly from application-level code.
+   Passing the optional *timeout* parameter will set the timeout on the socket
+   instance (if it is not given or ``None``, the global default timeout setting is
+   used).
+
+   .. versionadded:: 2.6
+
+
+.. function:: getaddrinfo(host, port[, family[, socktype[, proto[, flags]]]])
+
+   Resolves the *host*/*port* argument, into a sequence of 5-tuples that contain
+   all the necessary argument for the sockets manipulation. *host* is a domain
+   name, a string representation of IPv4/v6 address or ``None``. *port* is a string
+   service name (like ``'http'``), a numeric port number or ``None``.
+
+   The rest of the arguments are optional and must be numeric if specified.  For
+   *host* and *port*, by passing either an empty string or ``None``, you can pass
+   ``NULL`` to the C API.  The :func:`getaddrinfo` function returns a list of
+   5-tuples with the following structure:
+
+   ``(family, socktype, proto, canonname, sockaddr)``
+
+   *family*, *socktype*, *proto* are all integer and are meant to be passed to the
+   :func:`socket` function. *canonname* is a string representing the canonical name
+   of the *host*. It can be a numeric IPv4/v6 address when :const:`AI_CANONNAME` is
+   specified for a numeric *host*. *sockaddr* is a tuple describing a socket
+   address, as described above. See the source for the :mod:`httplib` and other
+   library modules for a typical usage of the function.
+
+   .. versionadded:: 2.2
+
+
+.. function:: getfqdn([name])
+
+   Return a fully qualified domain name for *name*. If *name* is omitted or empty,
+   it is interpreted as the local host.  To find the fully qualified name, the
+   hostname returned by :func:`gethostbyaddr` is checked, then aliases for the
+   host, if available.  The first name which includes a period is selected.  In
+   case no fully qualified domain name is available, the hostname as returned by
+   :func:`gethostname` is returned.
+
+   .. versionadded:: 2.0
+
+
+.. function:: gethostbyname(hostname)
+
+   Translate a host name to IPv4 address format.  The IPv4 address is returned as a
+   string, such as  ``'100.50.200.5'``.  If the host name is an IPv4 address itself
+   it is returned unchanged.  See :func:`gethostbyname_ex` for a more complete
+   interface. :func:`gethostbyname` does not support IPv6 name resolution, and
+   :func:`getaddrinfo` should be used instead for IPv4/v6 dual stack support.
+
+
+.. function:: gethostbyname_ex(hostname)
+
+   Translate a host name to IPv4 address format, extended interface. Return a
+   triple ``(hostname, aliaslist, ipaddrlist)`` where *hostname* is the primary
+   host name responding to the given *ip_address*, *aliaslist* is a (possibly
+   empty) list of alternative host names for the same address, and *ipaddrlist* is
+   a list of IPv4 addresses for the same interface on the same host (often but not
+   always a single address). :func:`gethostbyname_ex` does not support IPv6 name
+   resolution, and :func:`getaddrinfo` should be used instead for IPv4/v6 dual
+   stack support.
+
+
+.. function:: gethostname()
+
+   Return a string containing the hostname of the machine where  the Python
+   interpreter is currently executing. If you want to know the current machine's IP
+   address, you may want to use ``gethostbyname(gethostname())``. This operation
+   assumes that there is a valid address-to-host mapping for the host, and the
+   assumption does not always hold. Note: :func:`gethostname` doesn't always return
+   the fully qualified domain name; use ``getfqdn()`` (see above).
+
+
+.. function:: gethostbyaddr(ip_address)
+
+   Return a triple ``(hostname, aliaslist, ipaddrlist)`` where *hostname* is the
+   primary host name responding to the given *ip_address*, *aliaslist* is a
+   (possibly empty) list of alternative host names for the same address, and
+   *ipaddrlist* is a list of IPv4/v6 addresses for the same interface on the same
+   host (most likely containing only a single address). To find the fully qualified
+   domain name, use the function :func:`getfqdn`. :func:`gethostbyaddr` supports
+   both IPv4 and IPv6.
+
+
+.. function:: getnameinfo(sockaddr, flags)
+
+   Translate a socket address *sockaddr* into a 2-tuple ``(host, port)``. Depending
+   on the settings of *flags*, the result can contain a fully-qualified domain name
+   or numeric address representation in *host*.  Similarly, *port* can contain a
+   string port name or a numeric port number.
+
+   .. versionadded:: 2.2
+
+
+.. function:: getprotobyname(protocolname)
+
+   Translate an Internet protocol name (for example, ``'icmp'``) to a constant
+   suitable for passing as the (optional) third argument to the :func:`socket`
+   function.  This is usually only needed for sockets opened in "raw" mode
+   (:const:`SOCK_RAW`); for the normal socket modes, the correct protocol is chosen
+   automatically if the protocol is omitted or zero.
+
+
+.. function:: getservbyname(servicename[, protocolname])
+
+   Translate an Internet service name and protocol name to a port number for that
+   service.  The optional protocol name, if given, should be ``'tcp'`` or
+   ``'udp'``, otherwise any protocol will match.
+
+
+.. function:: getservbyport(port[, protocolname])
+
+   Translate an Internet port number and protocol name to a service name for that
+   service.  The optional protocol name, if given, should be ``'tcp'`` or
+   ``'udp'``, otherwise any protocol will match.
+
+
+.. function:: socket([family[, type[, proto]]])
+
+   Create a new socket using the given address family, socket type and protocol
+   number.  The address family should be :const:`AF_INET` (the default),
+   :const:`AF_INET6` or :const:`AF_UNIX`.  The socket type should be
+   :const:`SOCK_STREAM` (the default), :const:`SOCK_DGRAM` or perhaps one of the
+   other ``SOCK_`` constants.  The protocol number is usually zero and may be
+   omitted in that case.
+
+
+.. function:: ssl(sock[, keyfile, certfile])
+
+   Initiate a SSL connection over the socket *sock*. *keyfile* is the name of a PEM
+   formatted file that contains your private key. *certfile* is a PEM formatted
+   certificate chain file. On success, a new :class:`SSLObject` is returned.
+
+   .. warning::
+
+      This does not do any certificate verification!
+
+
+.. function:: socketpair([family[, type[, proto]]])
+
+   Build a pair of connected socket objects using the given address family, socket
+   type, and protocol number.  Address family, socket type, and protocol number are
+   as for the :func:`socket` function above. The default family is :const:`AF_UNIX`
+   if defined on the platform; otherwise, the default is :const:`AF_INET`.
+   Availability: Unix.
+
+   .. versionadded:: 2.4
+
+
+.. function:: fromfd(fd, family, type[, proto])
+
+   Duplicate the file descriptor *fd* (an integer as returned by a file object's
+   :meth:`fileno` method) and build a socket object from the result.  Address
+   family, socket type and protocol number are as for the :func:`socket` function
+   above. The file descriptor should refer to a socket, but this is not checked ---
+   subsequent operations on the object may fail if the file descriptor is invalid.
+   This function is rarely needed, but can be used to get or set socket options on
+   a socket passed to a program as standard input or output (such as a server
+   started by the Unix inet daemon).  The socket is assumed to be in blocking mode.
+   Availability: Unix.
+
+
+.. function:: ntohl(x)
+
+   Convert 32-bit positive integers from network to host byte order.  On machines
+   where the host byte order is the same as network byte order, this is a no-op;
+   otherwise, it performs a 4-byte swap operation.
+
+
+.. function:: ntohs(x)
+
+   Convert 16-bit positive integers from network to host byte order.  On machines
+   where the host byte order is the same as network byte order, this is a no-op;
+   otherwise, it performs a 2-byte swap operation.
+
+
+.. function:: htonl(x)
+
+   Convert 32-bit positive integers from host to network byte order.  On machines
+   where the host byte order is the same as network byte order, this is a no-op;
+   otherwise, it performs a 4-byte swap operation.
+
+
+.. function:: htons(x)
+
+   Convert 16-bit positive integers from host to network byte order.  On machines
+   where the host byte order is the same as network byte order, this is a no-op;
+   otherwise, it performs a 2-byte swap operation.
+
+
+.. function:: inet_aton(ip_string)
+
+   Convert an IPv4 address from dotted-quad string format (for example,
+   '123.45.67.89') to 32-bit packed binary format, as a string four characters in
+   length.  This is useful when conversing with a program that uses the standard C
+   library and needs objects of type :ctype:`struct in_addr`, which is the C type
+   for the 32-bit packed binary this function returns.
+
+   If the IPv4 address string passed to this function is invalid,
+   :exc:`socket.error` will be raised. Note that exactly what is valid depends on
+   the underlying C implementation of :cfunc:`inet_aton`.
+
+   :func:`inet_aton` does not support IPv6, and :func:`getnameinfo` should be used
+   instead for IPv4/v6 dual stack support.
+
+
+.. function:: inet_ntoa(packed_ip)
+
+   Convert a 32-bit packed IPv4 address (a string four characters in length) to its
+   standard dotted-quad string representation (for example, '123.45.67.89').  This
+   is useful when conversing with a program that uses the standard C library and
+   needs objects of type :ctype:`struct in_addr`, which is the C type for the
+   32-bit packed binary data this function takes as an argument.
+
+   If the string passed to this function is not exactly 4 bytes in length,
+   :exc:`socket.error` will be raised. :func:`inet_ntoa` does not support IPv6, and
+   :func:`getnameinfo` should be used instead for IPv4/v6 dual stack support.
+
+
+.. function:: inet_pton(address_family, ip_string)
+
+   Convert an IP address from its family-specific string format to a packed, binary
+   format. :func:`inet_pton` is useful when a library or network protocol calls for
+   an object of type :ctype:`struct in_addr` (similar to :func:`inet_aton`) or
+   :ctype:`struct in6_addr`.
+
+   Supported values for *address_family* are currently :const:`AF_INET` and
+   :const:`AF_INET6`. If the IP address string *ip_string* is invalid,
+   :exc:`socket.error` will be raised. Note that exactly what is valid depends on
+   both the value of *address_family* and the underlying implementation of
+   :cfunc:`inet_pton`.
+
+   Availability: Unix (maybe not all platforms).
+
+   .. versionadded:: 2.3
+
+
+.. function:: inet_ntop(address_family, packed_ip)
+
+   Convert a packed IP address (a string of some number of characters) to its
+   standard, family-specific string representation (for example, ``'7.10.0.5'`` or
+   ``'5aef:2b::8'``) :func:`inet_ntop` is useful when a library or network protocol
+   returns an object of type :ctype:`struct in_addr` (similar to :func:`inet_ntoa`)
+   or :ctype:`struct in6_addr`.
+
+   Supported values for *address_family* are currently :const:`AF_INET` and
+   :const:`AF_INET6`. If the string *packed_ip* is not the correct length for the
+   specified address family, :exc:`ValueError` will be raised.  A
+   :exc:`socket.error` is raised for errors from the call to :func:`inet_ntop`.
+
+   Availability: Unix (maybe not all platforms).
+
+   .. versionadded:: 2.3
+
+
+.. function:: getdefaulttimeout()
+
+   Return the default timeout in floating seconds for new socket objects. A value
+   of ``None`` indicates that new socket objects have no timeout. When the socket
+   module is first imported, the default is ``None``.
+
+   .. versionadded:: 2.3
+
+
+.. function:: setdefaulttimeout(timeout)
+
+   Set the default timeout in floating seconds for new socket objects. A value of
+   ``None`` indicates that new socket objects have no timeout. When the socket
+   module is first imported, the default is ``None``.
+
+   .. versionadded:: 2.3
+
+
+.. data:: SocketType
+
+   This is a Python type object that represents the socket object type. It is the
+   same as ``type(socket(...))``.
+
+
+.. seealso::
+
+   Module :mod:`SocketServer`
+      Classes that simplify writing network servers.
+
+
+.. _socket-objects:
+
+Socket Objects
+--------------
+
+Socket objects have the following methods.  Except for :meth:`makefile` these
+correspond to Unix system calls applicable to sockets.
+
+
+.. method:: socket.accept()
+
+   Accept a connection. The socket must be bound to an address and listening for
+   connections. The return value is a pair ``(conn, address)`` where *conn* is a
+   *new* socket object usable to send and receive data on the connection, and
+   *address* is the address bound to the socket on the other end of the connection.
+
+
+.. method:: socket.bind(address)
+
+   Bind the socket to *address*.  The socket must not already be bound. (The format
+   of *address* depends on the address family --- see above.)
+
+   .. note::
+
+      This method has historically accepted a pair of parameters for :const:`AF_INET`
+      addresses instead of only a tuple.  This was never intentional and is no longer
+      available in Python 2.0 and later.
+
+
+.. method:: socket.close()
+
+   Close the socket.  All future operations on the socket object will fail. The
+   remote end will receive no more data (after queued data is flushed). Sockets are
+   automatically closed when they are garbage-collected.
+
+
+.. method:: socket.connect(address)
+
+   Connect to a remote socket at *address*. (The format of *address* depends on the
+   address family --- see above.)
+
+   .. note::
+
+      This method has historically accepted a pair of parameters for :const:`AF_INET`
+      addresses instead of only a tuple.  This was never intentional and is no longer
+      available in Python 2.0 and later.
+
+
+.. method:: socket.connect_ex(address)
+
+   Like ``connect(address)``, but return an error indicator instead of raising an
+   exception for errors returned by the C-level :cfunc:`connect` call (other
+   problems, such as "host not found," can still raise exceptions).  The error
+   indicator is ``0`` if the operation succeeded, otherwise the value of the
+   :cdata:`errno` variable.  This is useful to support, for example, asynchronous
+   connects.
+
+   .. note::
+
+      This method has historically accepted a pair of parameters for :const:`AF_INET`
+      addresses instead of only a tuple. This was never intentional and is no longer
+      available in Python 2.0 and later.
+
+
+.. method:: socket.fileno()
+
+   Return the socket's file descriptor (a small integer).  This is useful with
+   :func:`select.select`.
+
+   Under Windows the small integer returned by this method cannot be used where a
+   file descriptor can be used (such as :func:`os.fdopen`).  Unix does not have
+   this limitation.
+
+
+.. method:: socket.getpeername()
+
+   Return the remote address to which the socket is connected.  This is useful to
+   find out the port number of a remote IPv4/v6 socket, for instance. (The format
+   of the address returned depends on the address family --- see above.)  On some
+   systems this function is not supported.
+
+
+.. method:: socket.getsockname()
+
+   Return the socket's own address.  This is useful to find out the port number of
+   an IPv4/v6 socket, for instance. (The format of the address returned depends on
+   the address family --- see above.)
+
+
+.. method:: socket.getsockopt(level, optname[, buflen])
+
+   Return the value of the given socket option (see the Unix man page
+   :manpage:`getsockopt(2)`).  The needed symbolic constants (:const:`SO_\*` etc.)
+   are defined in this module.  If *buflen* is absent, an integer option is assumed
+   and its integer value is returned by the function.  If *buflen* is present, it
+   specifies the maximum length of the buffer used to receive the option in, and
+   this buffer is returned as a string.  It is up to the caller to decode the
+   contents of the buffer (see the optional built-in module :mod:`struct` for a way
+   to decode C structures encoded as strings).
+
+
+.. method:: socket.listen(backlog)
+
+   Listen for connections made to the socket.  The *backlog* argument specifies the
+   maximum number of queued connections and should be at least 1; the maximum value
+   is system-dependent (usually 5).
+
+
+.. method:: socket.makefile([mode[, bufsize]])
+
+   .. index:: single: I/O control; buffering
+
+   Return a :dfn:`file object` associated with the socket.  (File objects are
+   described in :ref:`bltin-file-objects`.) The file object
+   references a :cfunc:`dup`\ ped version of the socket file descriptor, so the
+   file object and socket object may be closed or garbage-collected independently.
+   The socket must be in blocking mode (it can not have a timeout). The optional
+   *mode* and *bufsize* arguments are interpreted the same way as by the built-in
+   :func:`file` function; see :ref:`built-in-funcs` for more information.
+
+
+.. method:: socket.recv(bufsize[, flags])
+
+   Receive data from the socket.  The return value is a string representing the
+   data received.  The maximum amount of data to be received at once is specified
+   by *bufsize*.  See the Unix manual page :manpage:`recv(2)` for the meaning of
+   the optional argument *flags*; it defaults to zero.
+
+   .. note::
+
+      For best match with hardware and network realities, the value of  *bufsize*
+      should be a relatively small power of 2, for example, 4096.
+
+
+.. method:: socket.recvfrom(bufsize[, flags])
+
+   Receive data from the socket.  The return value is a pair ``(string, address)``
+   where *string* is a string representing the data received and *address* is the
+   address of the socket sending the data.  See the Unix manual page
+   :manpage:`recv(2)` for the meaning of the optional argument *flags*; it defaults
+   to zero. (The format of *address* depends on the address family --- see above.)
+
+
+.. method:: socket.recvfrom_into(buffer[, nbytes[, flags]])
+
+   Receive data from the socket, writing it into *buffer* instead of  creating a
+   new string.  The return value is a pair ``(nbytes, address)`` where *nbytes* is
+   the number of bytes received and *address* is the address of the socket sending
+   the data.  See the Unix manual page :manpage:`recv(2)` for the meaning of the
+   optional argument *flags*; it defaults to zero.  (The format of *address*
+   depends on the address family --- see above.)
+
+   .. versionadded:: 2.5
+
+
+.. method:: socket.recv_into(buffer[, nbytes[, flags]])
+
+   Receive up to *nbytes* bytes from the socket, storing the data into a buffer
+   rather than creating a new string.     If *nbytes* is not specified (or 0),
+   receive up to the size available in the given buffer. See the Unix manual page
+   :manpage:`recv(2)` for the meaning of the optional argument *flags*; it defaults
+   to zero.
+
+   .. versionadded:: 2.5
+
+
+.. method:: socket.send(string[, flags])
+
+   Send data to the socket.  The socket must be connected to a remote socket.  The
+   optional *flags* argument has the same meaning as for :meth:`recv` above.
+   Returns the number of bytes sent. Applications are responsible for checking that
+   all data has been sent; if only some of the data was transmitted, the
+   application needs to attempt delivery of the remaining data.
+
+
+.. method:: socket.sendall(string[, flags])
+
+   Send data to the socket.  The socket must be connected to a remote socket.  The
+   optional *flags* argument has the same meaning as for :meth:`recv` above.
+   Unlike :meth:`send`, this method continues to send data from *string* until
+   either all data has been sent or an error occurs.  ``None`` is returned on
+   success.  On error, an exception is raised, and there is no way to determine how
+   much data, if any, was successfully sent.
+
+
+.. method:: socket.sendto(string[, flags], address)
+
+   Send data to the socket.  The socket should not be connected to a remote socket,
+   since the destination socket is specified by *address*.  The optional *flags*
+   argument has the same meaning as for :meth:`recv` above.  Return the number of
+   bytes sent. (The format of *address* depends on the address family --- see
+   above.)
+
+
+.. method:: socket.setblocking(flag)
+
+   Set blocking or non-blocking mode of the socket: if *flag* is 0, the socket is
+   set to non-blocking, else to blocking mode.  Initially all sockets are in
+   blocking mode.  In non-blocking mode, if a :meth:`recv` call doesn't find any
+   data, or if a :meth:`send` call can't immediately dispose of the data, a
+   :exc:`error` exception is raised; in blocking mode, the calls block until they
+   can proceed. ``s.setblocking(0)`` is equivalent to ``s.settimeout(0)``;
+   ``s.setblocking(1)`` is equivalent to ``s.settimeout(None)``.
+
+
+.. method:: socket.settimeout(value)
+
+   Set a timeout on blocking socket operations.  The *value* argument can be a
+   nonnegative float expressing seconds, or ``None``. If a float is given,
+   subsequent socket operations will raise an :exc:`timeout` exception if the
+   timeout period *value* has elapsed before the operation has completed.  Setting
+   a timeout of ``None`` disables timeouts on socket operations.
+   ``s.settimeout(0.0)`` is equivalent to ``s.setblocking(0)``;
+   ``s.settimeout(None)`` is equivalent to ``s.setblocking(1)``.
+
+   .. versionadded:: 2.3
+
+
+.. method:: socket.gettimeout()
+
+   Return the timeout in floating seconds associated with socket operations, or
+   ``None`` if no timeout is set.  This reflects the last call to
+   :meth:`setblocking` or :meth:`settimeout`.
+
+   .. versionadded:: 2.3
+
+Some notes on socket blocking and timeouts: A socket object can be in one of
+three modes: blocking, non-blocking, or timeout.  Sockets are always created in
+blocking mode.  In blocking mode, operations block until complete.  In
+non-blocking mode, operations fail (with an error that is unfortunately
+system-dependent) if they cannot be completed immediately.  In timeout mode,
+operations fail if they cannot be completed within the timeout specified for the
+socket.  The :meth:`setblocking` method is simply a shorthand for certain
+:meth:`settimeout` calls.
+
+Timeout mode internally sets the socket in non-blocking mode.  The blocking and
+timeout modes are shared between file descriptors and socket objects that refer
+to the same network endpoint.  A consequence of this is that file objects
+returned by the :meth:`makefile` method must only be used when the socket is in
+blocking mode; in timeout or non-blocking mode file operations that cannot be
+completed immediately will fail.
+
+Note that the :meth:`connect` operation is subject to the timeout setting, and
+in general it is recommended to call :meth:`settimeout` before calling
+:meth:`connect`.
+
+
+.. method:: socket.setsockopt(level, optname, value)
+
+   .. index:: module: struct
+
+   Set the value of the given socket option (see the Unix manual page
+   :manpage:`setsockopt(2)`).  The needed symbolic constants are defined in the
+   :mod:`socket` module (:const:`SO_\*` etc.).  The value can be an integer or a
+   string representing a buffer.  In the latter case it is up to the caller to
+   ensure that the string contains the proper bits (see the optional built-in
+   module :mod:`struct` for a way to encode C structures as strings).
+
+
+.. method:: socket.shutdown(how)
+
+   Shut down one or both halves of the connection.  If *how* is :const:`SHUT_RD`,
+   further receives are disallowed.  If *how* is :const:`SHUT_WR`, further sends
+   are disallowed.  If *how* is :const:`SHUT_RDWR`, further sends and receives are
+   disallowed.
+
+Note that there are no methods :meth:`read` or :meth:`write`; use :meth:`recv`
+and :meth:`send` without *flags* argument instead.
+
+Socket objects also have these (read-only) attributes that correspond to the
+values given to the :class:`socket` constructor.
+
+
+.. attribute:: socket.family
+
+   The socket family.
+
+   .. versionadded:: 2.5
+
+
+.. attribute:: socket.type
+
+   The socket type.
+
+   .. versionadded:: 2.5
+
+
+.. attribute:: socket.proto
+
+   The socket protocol.
+
+   .. versionadded:: 2.5
+
+
+.. _ssl-objects:
+
+SSL Objects
+-----------
+
+SSL objects have the following methods.
+
+
+.. method:: SSL.write(s)
+
+   Writes the string *s* to the on the object's SSL connection. The return value is
+   the number of bytes written.
+
+
+.. method:: SSL.read([n])
+
+   If *n* is provided, read *n* bytes from the SSL connection, otherwise read until
+   EOF. The return value is a string of the bytes read.
+
+
+.. method:: SSL.server()
+
+   Returns a string describing the server's certificate. Useful for debugging
+   purposes; do not parse the content of this string because its format can't be
+   parsed unambiguously.
+
+
+.. method:: SSL.issuer()
+
+   Returns a string describing the issuer of the server's certificate. Useful for
+   debugging purposes; do not parse the content of this string because its format
+   can't be parsed unambiguously.
+
+
+.. _socket-example:
+
+Example
+-------
+
+Here are four minimal example programs using the TCP/IP protocol: a server that
+echoes all data that it receives back (servicing only one client), and a client
+using it.  Note that a server must perform the sequence :func:`socket`,
+:meth:`bind`, :meth:`listen`, :meth:`accept` (possibly repeating the
+:meth:`accept` to service more than one client), while a client only needs the
+sequence :func:`socket`, :meth:`connect`.  Also note that the server does not
+:meth:`send`/:meth:`recv` on the  socket it is listening on but on the new
+socket returned by :meth:`accept`.
+
+The first two examples support IPv4 only. ::
+
+   # Echo server program
+   import socket
+
+   HOST = ''                 # Symbolic name meaning the local host
+   PORT = 50007              # Arbitrary non-privileged port
+   s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+   s.bind((HOST, PORT))
+   s.listen(1)
+   conn, addr = s.accept()
+   print 'Connected by', addr
+   while 1:
+       data = conn.recv(1024)
+       if not data: break
+       conn.send(data)
+   conn.close()
+
+::
+
+   # Echo client program
+   import socket
+
+   HOST = 'daring.cwi.nl'    # The remote host
+   PORT = 50007              # The same port as used by the server
+   s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+   s.connect((HOST, PORT))
+   s.send('Hello, world')
+   data = s.recv(1024)
+   s.close()
+   print 'Received', repr(data)
+
+The next two examples are identical to the above two, but support both IPv4 and
+IPv6. The server side will listen to the first address family available (it
+should listen to both instead). On most of IPv6-ready systems, IPv6 will take
+precedence and the server may not accept IPv4 traffic. The client side will try
+to connect to the all addresses returned as a result of the name resolution, and
+sends traffic to the first one connected successfully. ::
+
+   # Echo server program
+   import socket
+   import sys
+
+   HOST = ''                 # Symbolic name meaning the local host
+   PORT = 50007              # Arbitrary non-privileged port
+   s = None
+   for res in socket.getaddrinfo(HOST, PORT, socket.AF_UNSPEC, socket.SOCK_STREAM, 0, socket.AI_PASSIVE):
+       af, socktype, proto, canonname, sa = res
+       try:
+   	s = socket.socket(af, socktype, proto)
+       except socket.error as msg:
+   	s = None
+   	continue
+       try:
+   	s.bind(sa)
+   	s.listen(1)
+       except socket.error as msg:
+   	s.close()
+   	s = None
+   	continue
+       break
+   if s is None:
+       print 'could not open socket'
+       sys.exit(1)
+   conn, addr = s.accept()
+   print 'Connected by', addr
+   while 1:
+       data = conn.recv(1024)
+       if not data: break
+       conn.send(data)
+   conn.close()
+
+::
+
+   # Echo client program
+   import socket
+   import sys
+
+   HOST = 'daring.cwi.nl'    # The remote host
+   PORT = 50007              # The same port as used by the server
+   s = None
+   for res in socket.getaddrinfo(HOST, PORT, socket.AF_UNSPEC, socket.SOCK_STREAM):
+       af, socktype, proto, canonname, sa = res
+       try:
+   	s = socket.socket(af, socktype, proto)
+       except socket.error as msg:
+   	s = None
+   	continue
+       try:
+   	s.connect(sa)
+       except socket.error as msg:
+   	s.close()
+   	s = None
+   	continue
+       break
+   if s is None:
+       print 'could not open socket'
+       sys.exit(1)
+   s.send('Hello, world')
+   data = s.recv(1024)
+   s.close()
+   print 'Received', repr(data)
+
+This example connects to an SSL server, prints the  server and issuer's
+distinguished names, sends some bytes, and reads part of the response::
+
+   import socket
+
+   s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+   s.connect(('www.verisign.com', 443))
+
+   ssl_sock = socket.ssl(s)
+
+   print repr(ssl_sock.server())
+   print repr(ssl_sock.issuer())
+
+   # Set a simple HTTP request -- use httplib in actual code.
+   ssl_sock.write("""GET / HTTP/1.0\r
+   Host: www.verisign.com\r\n\r\n""")
+
+   # Read a chunk of data.  Will not necessarily
+   # read all the data returned by the server.
+   data = ssl_sock.read()
+
+   # Note that you need to close the underlying socket, not the SSL object.
+   del ssl_sock
+   s.close()
+
+At this writing, this SSL example prints the following output (line breaks
+inserted for readability)::
+
+   '/C=US/ST=California/L=Mountain View/
+    O=VeriSign, Inc./OU=Production Services/
+    OU=Terms of use at www.verisign.com/rpa (c)00/
+    CN=www.verisign.com'
+   '/O=VeriSign Trust Network/OU=VeriSign, Inc./
+    OU=VeriSign International Server CA - Class 3/
+    OU=www.verisign.com/CPS Incorp.by Ref. LIABILITY LTD.(c)97 VeriSign'
+
diff --git a/Doc/library/socketserver.rst b/Doc/library/socketserver.rst
new file mode 100644
index 0000000..96fae6b
--- /dev/null
+++ b/Doc/library/socketserver.rst
@@ -0,0 +1,295 @@
+
+:mod:`SocketServer` --- A framework for network servers
+=======================================================
+
+.. module:: SocketServer
+   :synopsis: A framework for network servers.
+
+
+The :mod:`SocketServer` module simplifies the task of writing network servers.
+
+There are four basic server classes: :class:`TCPServer` uses the Internet TCP
+protocol, which provides for continuous streams of data between the client and
+server.  :class:`UDPServer` uses datagrams, which are discrete packets of
+information that may arrive out of order or be lost while in transit.  The more
+infrequently used :class:`UnixStreamServer` and :class:`UnixDatagramServer`
+classes are similar, but use Unix domain sockets; they're not available on
+non-Unix platforms.  For more details on network programming, consult a book
+such as
+W. Richard Steven's UNIX Network Programming or Ralph Davis's Win32 Network
+Programming.
+
+These four classes process requests :dfn:`synchronously`; each request must be
+completed before the next request can be started.  This isn't suitable if each
+request takes a long time to complete, because it requires a lot of computation,
+or because it returns a lot of data which the client is slow to process.  The
+solution is to create a separate process or thread to handle each request; the
+:class:`ForkingMixIn` and :class:`ThreadingMixIn` mix-in classes can be used to
+support asynchronous behaviour.
+
+Creating a server requires several steps.  First, you must create a request
+handler class by subclassing the :class:`BaseRequestHandler` class and
+overriding its :meth:`handle` method; this method will process incoming
+requests.  Second, you must instantiate one of the server classes, passing it
+the server's address and the request handler class.  Finally, call the
+:meth:`handle_request` or :meth:`serve_forever` method of the server object to
+process one or many requests.
+
+When inheriting from :class:`ThreadingMixIn` for threaded connection behavior,
+you should explicitly declare how you want your threads to behave on an abrupt
+shutdown. The :class:`ThreadingMixIn` class defines an attribute
+*daemon_threads*, which indicates whether or not the server should wait for
+thread termination. You should set the flag explicitly if you would like threads
+to behave autonomously; the default is :const:`False`, meaning that Python will
+not exit until all threads created by :class:`ThreadingMixIn` have exited.
+
+Server classes have the same external methods and attributes, no matter what
+network protocol they use:
+
+
+Server Creation Notes
+---------------------
+
+There are five classes in an inheritance diagram, four of which represent
+synchronous servers of four types::
+
+   +------------+
+   | BaseServer |
+   +------------+
+         |
+         v
+   +-----------+        +------------------+
+   | TCPServer |------->| UnixStreamServer |
+   +-----------+        +------------------+
+         |
+         v
+   +-----------+        +--------------------+
+   | UDPServer |------->| UnixDatagramServer |
+   +-----------+        +--------------------+
+
+Note that :class:`UnixDatagramServer` derives from :class:`UDPServer`, not from
+:class:`UnixStreamServer` --- the only difference between an IP and a Unix
+stream server is the address family, which is simply repeated in both Unix
+server classes.
+
+Forking and threading versions of each type of server can be created using the
+:class:`ForkingMixIn` and :class:`ThreadingMixIn` mix-in classes.  For instance,
+a threading UDP server class is created as follows::
+
+   class ThreadingUDPServer(ThreadingMixIn, UDPServer): pass
+
+The mix-in class must come first, since it overrides a method defined in
+:class:`UDPServer`.  Setting the various member variables also changes the
+behavior of the underlying server mechanism.
+
+To implement a service, you must derive a class from :class:`BaseRequestHandler`
+and redefine its :meth:`handle` method.  You can then run various versions of
+the service by combining one of the server classes with your request handler
+class.  The request handler class must be different for datagram or stream
+services.  This can be hidden by using the handler subclasses
+:class:`StreamRequestHandler` or :class:`DatagramRequestHandler`.
+
+Of course, you still have to use your head!  For instance, it makes no sense to
+use a forking server if the service contains state in memory that can be
+modified by different requests, since the modifications in the child process
+would never reach the initial state kept in the parent process and passed to
+each child.  In this case, you can use a threading server, but you will probably
+have to use locks to protect the integrity of the shared data.
+
+On the other hand, if you are building an HTTP server where all data is stored
+externally (for instance, in the file system), a synchronous class will
+essentially render the service "deaf" while one request is being handled --
+which may be for a very long time if a client is slow to receive all the data it
+has requested.  Here a threading or forking server is appropriate.
+
+In some cases, it may be appropriate to process part of a request synchronously,
+but to finish processing in a forked child depending on the request data.  This
+can be implemented by using a synchronous server and doing an explicit fork in
+the request handler class :meth:`handle` method.
+
+Another approach to handling multiple simultaneous requests in an environment
+that supports neither threads nor :func:`fork` (or where these are too expensive
+or inappropriate for the service) is to maintain an explicit table of partially
+finished requests and to use :func:`select` to decide which request to work on
+next (or whether to handle a new incoming request).  This is particularly
+important for stream services where each client can potentially be connected for
+a long time (if threads or subprocesses cannot be used).
+
+.. % XXX should data and methods be intermingled, or separate?
+.. % how should the distinction between class and instance variables be
+.. % drawn?
+
+
+Server Objects
+--------------
+
+
+.. function:: fileno()
+
+   Return an integer file descriptor for the socket on which the server is
+   listening.  This function is most commonly passed to :func:`select.select`, to
+   allow monitoring multiple servers in the same process.
+
+
+.. function:: handle_request()
+
+   Process a single request.  This function calls the following methods in order:
+   :meth:`get_request`, :meth:`verify_request`, and :meth:`process_request`.  If
+   the user-provided :meth:`handle` method of the handler class raises an
+   exception, the server's :meth:`handle_error` method will be called.
+
+
+.. function:: serve_forever()
+
+   Handle an infinite number of requests.  This simply calls :meth:`handle_request`
+   inside an infinite loop.
+
+
+.. data:: address_family
+
+   The family of protocols to which the server's socket belongs.
+   :const:`socket.AF_INET` and :const:`socket.AF_UNIX` are two possible values.
+
+
+.. data:: RequestHandlerClass
+
+   The user-provided request handler class; an instance of this class is created
+   for each request.
+
+
+.. data:: server_address
+
+   The address on which the server is listening.  The format of addresses varies
+   depending on the protocol family; see the documentation for the socket module
+   for details.  For Internet protocols, this is a tuple containing a string giving
+   the address, and an integer port number: ``('127.0.0.1', 80)``, for example.
+
+
+.. data:: socket
+
+   The socket object on which the server will listen for incoming requests.
+
+The server classes support the following class variables:
+
+.. % XXX should class variables be covered before instance variables, or
+.. % vice versa?
+
+
+.. data:: allow_reuse_address
+
+   Whether the server will allow the reuse of an address. This defaults to
+   :const:`False`, and can be set in subclasses to change the policy.
+
+
+.. data:: request_queue_size
+
+   The size of the request queue.  If it takes a long time to process a single
+   request, any requests that arrive while the server is busy are placed into a
+   queue, up to :attr:`request_queue_size` requests.  Once the queue is full,
+   further requests from clients will get a "Connection denied" error.  The default
+   value is usually 5, but this can be overridden by subclasses.
+
+
+.. data:: socket_type
+
+   The type of socket used by the server; :const:`socket.SOCK_STREAM` and
+   :const:`socket.SOCK_DGRAM` are two possible values.
+
+There are various server methods that can be overridden by subclasses of base
+server classes like :class:`TCPServer`; these methods aren't useful to external
+users of the server object.
+
+.. % should the default implementations of these be documented, or should
+.. % it be assumed that the user will look at SocketServer.py?
+
+
+.. function:: finish_request()
+
+   Actually processes the request by instantiating :attr:`RequestHandlerClass` and
+   calling its :meth:`handle` method.
+
+
+.. function:: get_request()
+
+   Must accept a request from the socket, and return a 2-tuple containing the *new*
+   socket object to be used to communicate with the client, and the client's
+   address.
+
+
+.. function:: handle_error(request, client_address)
+
+   This function is called if the :attr:`RequestHandlerClass`'s :meth:`handle`
+   method raises an exception.  The default action is to print the traceback to
+   standard output and continue handling further requests.
+
+
+.. function:: process_request(request, client_address)
+
+   Calls :meth:`finish_request` to create an instance of the
+   :attr:`RequestHandlerClass`.  If desired, this function can create a new process
+   or thread to handle the request; the :class:`ForkingMixIn` and
+   :class:`ThreadingMixIn` classes do this.
+
+.. % Is there any point in documenting the following two functions?
+.. % What would the purpose of overriding them be: initializing server
+.. % instance variables, adding new network families?
+
+
+.. function:: server_activate()
+
+   Called by the server's constructor to activate the server.  The default behavior
+   just :meth:`listen`\ s to the server's socket. May be overridden.
+
+
+.. function:: server_bind()
+
+   Called by the server's constructor to bind the socket to the desired address.
+   May be overridden.
+
+
+.. function:: verify_request(request, client_address)
+
+   Must return a Boolean value; if the value is :const:`True`, the request will be
+   processed, and if it's :const:`False`, the request will be denied. This function
+   can be overridden to implement access controls for a server. The default
+   implementation always returns :const:`True`.
+
+
+RequestHandler Objects
+----------------------
+
+The request handler class must define a new :meth:`handle` method, and can
+override any of the following methods.  A new instance is created for each
+request.
+
+
+.. function:: finish()
+
+   Called after the :meth:`handle` method to perform any clean-up actions required.
+   The default implementation does nothing.  If :meth:`setup` or :meth:`handle`
+   raise an exception, this function will not be called.
+
+
+.. function:: handle()
+
+   This function must do all the work required to service a request. The default
+   implementation does nothing. Several instance attributes are available to it;
+   the request is available as :attr:`self.request`; the client address as
+   :attr:`self.client_address`; and the server instance as :attr:`self.server`, in
+   case it needs access to per-server information.
+
+   The type of :attr:`self.request` is different for datagram or stream services.
+   For stream services, :attr:`self.request` is a socket object; for datagram
+   services, :attr:`self.request` is a string. However, this can be hidden by using
+   the  request handler subclasses :class:`StreamRequestHandler` or
+   :class:`DatagramRequestHandler`, which override the :meth:`setup` and
+   :meth:`finish` methods, and provide :attr:`self.rfile` and :attr:`self.wfile`
+   attributes. :attr:`self.rfile` and :attr:`self.wfile` can be read or written,
+   respectively, to get the request data or return data to the client.
+
+
+.. function:: setup()
+
+   Called before the :meth:`handle` method to perform any initialization actions
+   required.  The default implementation does nothing.
+
diff --git a/Doc/library/someos.rst b/Doc/library/someos.rst
new file mode 100644
index 0000000..5ee96bc
--- /dev/null
+++ b/Doc/library/someos.rst
@@ -0,0 +1,23 @@
+
+.. _someos:
+
+**********************************
+Optional Operating System Services
+**********************************
+
+The modules described in this chapter provide interfaces to operating system
+features that are available on selected operating systems only. The interfaces
+are generally modeled after the Unix or C interfaces but they are available on
+some other systems as well (e.g. Windows or NT).  Here's an overview:
+
+
+.. toctree::
+
+   select.rst
+   thread.rst
+   threading.rst
+   dummy_thread.rst
+   dummy_threading.rst
+   mmap.rst
+   readline.rst
+   rlcompleter.rst
diff --git a/Doc/library/spwd.rst b/Doc/library/spwd.rst
new file mode 100644
index 0000000..6cbe925
--- /dev/null
+++ b/Doc/library/spwd.rst
@@ -0,0 +1,74 @@
+
+:mod:`spwd` --- The shadow password database
+============================================
+
+.. module:: spwd
+   :platform: Unix
+   :synopsis: The shadow password database (getspnam() and friends).
+
+
+.. versionadded:: 2.5
+
+This module provides access to the Unix shadow password database. It is
+available on various Unix versions.
+
+You must have enough privileges to access the shadow password database (this
+usually means you have to be root).
+
+Shadow password database entries are reported as a tuple-like object, whose
+attributes correspond to the members of the ``spwd`` structure (Attribute field
+below, see ``<shadow.h>``):
+
++-------+---------------+---------------------------------+
+| Index | Attribute     | Meaning                         |
++=======+===============+=================================+
+| 0     | ``sp_nam``    | Login name                      |
++-------+---------------+---------------------------------+
+| 1     | ``sp_pwd``    | Encrypted password              |
++-------+---------------+---------------------------------+
+| 2     | ``sp_lstchg`` | Date of last change             |
++-------+---------------+---------------------------------+
+| 3     | ``sp_min``    | Minimal number of days between  |
+|       |               | changes                         |
++-------+---------------+---------------------------------+
+| 4     | ``sp_max``    | Maximum number of days between  |
+|       |               | changes                         |
++-------+---------------+---------------------------------+
+| 5     | ``sp_warn``   | Number of days before password  |
+|       |               | expires to warn user about it   |
++-------+---------------+---------------------------------+
+| 6     | ``sp_inact``  | Number of days after password   |
+|       |               | expires until account is        |
+|       |               | blocked                         |
++-------+---------------+---------------------------------+
+| 7     | ``sp_expire`` | Number of days since 1970-01-01 |
+|       |               | until account is disabled       |
++-------+---------------+---------------------------------+
+| 8     | ``sp_flag``   | Reserved                        |
++-------+---------------+---------------------------------+
+
+The sp_nam and sp_pwd items are strings, all others are integers.
+:exc:`KeyError` is raised if the entry asked for cannot be found.
+
+It defines the following items:
+
+
+.. function:: getspnam(name)
+
+   Return the shadow password database entry for the given user name.
+
+
+.. function:: getspall()
+
+   Return a list of all available shadow password database entries, in arbitrary
+   order.
+
+
+.. seealso::
+
+   Module :mod:`grp`
+      An interface to the group database, similar to this.
+
+   Module :mod:`pwd`
+      An interface to the normal password database, similar to this.
+
diff --git a/Doc/library/sqlite3.rst b/Doc/library/sqlite3.rst
new file mode 100644
index 0000000..707092b
--- /dev/null
+++ b/Doc/library/sqlite3.rst
@@ -0,0 +1,689 @@
+
+:mod:`sqlite3` --- DB-API 2.0 interface for SQLite databases
+============================================================
+
+.. module:: sqlite3
+   :synopsis: A DB-API 2.0 implementation using SQLite 3.x.
+.. sectionauthor:: Gerhard Häring <gh@ghaering.de>
+
+
+.. versionadded:: 2.5
+
+SQLite is a C library that provides a lightweight disk-based database that
+doesn't require a separate server process and allows accessing the database
+using a nonstandard variant of the SQL query language. Some applications can use
+SQLite for internal data storage.  It's also possible to prototype an
+application using SQLite and then port the code to a larger database such as
+PostgreSQL or Oracle.
+
+pysqlite was written by Gerhard Häring and provides a SQL interface compliant
+with the DB-API 2.0 specification described by :pep:`249`.
+
+To use the module, you must first create a :class:`Connection` object that
+represents the database.  Here the data will be stored in the
+:file:`/tmp/example` file::
+
+   conn = sqlite3.connect('/tmp/example')
+
+You can also supply the special name ``:memory:`` to create a database in RAM.
+
+Once you have a :class:`Connection`, you can create a :class:`Cursor`  object
+and call its :meth:`execute` method to perform SQL commands::
+
+   c = conn.cursor()
+
+   # Create table
+   c.execute('''create table stocks
+   (date text, trans text, symbol text,
+    qty real, price real)''')
+
+   # Insert a row of data
+   c.execute("""insert into stocks
+             values ('2006-01-05','BUY','RHAT',100,35.14)""")
+
+   # Save (commit) the changes
+   conn.commit()
+
+   # We can also close the cursor if we are done with it
+   c.close()
+
+Usually your SQL operations will need to use values from Python variables.  You
+shouldn't assemble your query using Python's string operations because doing so
+is insecure; it makes your program vulnerable to an SQL injection attack.
+
+Instead, use the DB-API's parameter substitution.  Put ``?`` as a placeholder
+wherever you want to use a value, and then provide a tuple of values as the
+second argument to the cursor's :meth:`execute` method.  (Other database modules
+may use a different placeholder, such as ``%s`` or ``:1``.) For example::
+
+   # Never do this -- insecure!
+   symbol = 'IBM'
+   c.execute("... where symbol = '%s'" % symbol)
+
+   # Do this instead
+   t = (symbol,)
+   c.execute('select * from stocks where symbol=?', t)
+
+   # Larger example
+   for t in (('2006-03-28', 'BUY', 'IBM', 1000, 45.00),
+             ('2006-04-05', 'BUY', 'MSOFT', 1000, 72.00),
+             ('2006-04-06', 'SELL', 'IBM', 500, 53.00),
+            ):
+       c.execute('insert into stocks values (?,?,?,?,?)', t)
+
+To retrieve data after executing a SELECT statement, you can either  treat the
+cursor as an iterator, call the cursor's :meth:`fetchone` method to retrieve a
+single matching row,  or call :meth:`fetchall` to get a list of the matching
+rows.
+
+This example uses the iterator form::
+
+   >>> c = conn.cursor()
+   >>> c.execute('select * from stocks order by price')
+   >>> for row in c:
+   ...    print row
+   ...
+   (u'2006-01-05', u'BUY', u'RHAT', 100, 35.140000000000001)
+   (u'2006-03-28', u'BUY', u'IBM', 1000, 45.0)
+   (u'2006-04-06', u'SELL', u'IBM', 500, 53.0)
+   (u'2006-04-05', u'BUY', u'MSOFT', 1000, 72.0)
+   >>>
+
+
+.. seealso::
+
+   http://www.pysqlite.org
+      The pysqlite web page.
+
+   http://www.sqlite.org
+      The SQLite web page; the documentation describes the syntax and the available
+      data types for the supported SQL dialect.
+
+   :pep:`249` - Database API Specification 2.0
+      PEP written by Marc-André Lemburg.
+
+
+.. _sqlite3-module-contents:
+
+Module functions and constants
+------------------------------
+
+
+.. data:: PARSE_DECLTYPES
+
+   This constant is meant to be used with the *detect_types* parameter of the
+   :func:`connect` function.
+
+   Setting it makes the :mod:`sqlite3` module parse the declared type for each
+   column it returns.  It will parse out the first word of the declared type, i. e.
+   for "integer primary key", it will parse out "integer". Then for that column, it
+   will look into the converters dictionary and use the converter function
+   registered for that type there.  Converter names are case-sensitive!
+
+
+.. data:: PARSE_COLNAMES
+
+   This constant is meant to be used with the *detect_types* parameter of the
+   :func:`connect` function.
+
+   Setting this makes the SQLite interface parse the column name for each column it
+   returns.  It will look for a string formed [mytype] in there, and then decide
+   that 'mytype' is the type of the column. It will try to find an entry of
+   'mytype' in the converters dictionary and then use the converter function found
+   there to return the value. The column name found in :attr:`cursor.description`
+   is only the first word of the column name, i.  e. if you use something like
+   ``'as "x [datetime]"'`` in your SQL, then we will parse out everything until the
+   first blank for the column name: the column name would simply be "x".
+
+
+.. function:: connect(database[, timeout, isolation_level, detect_types, factory])
+
+   Opens a connection to the SQLite database file *database*. You can use
+   ``":memory:"`` to open a database connection to a database that resides in RAM
+   instead of on disk.
+
+   When a database is accessed by multiple connections, and one of the processes
+   modifies the database, the SQLite database is locked until that transaction is
+   committed. The *timeout* parameter specifies how long the connection should wait
+   for the lock to go away until raising an exception. The default for the timeout
+   parameter is 5.0 (five seconds).
+
+   For the *isolation_level* parameter, please see the
+   :attr:`Connection.isolation_level` property of :class:`Connection` objects.
+
+   SQLite natively supports only the types TEXT, INTEGER, FLOAT, BLOB and NULL. If
+   you want to use other types you must add support for them yourself. The
+   *detect_types* parameter and the using custom **converters** registered with the
+   module-level :func:`register_converter` function allow you to easily do that.
+
+   *detect_types* defaults to 0 (i. e. off, no type detection), you can set it to
+   any combination of :const:`PARSE_DECLTYPES` and :const:`PARSE_COLNAMES` to turn
+   type detection on.
+
+   By default, the :mod:`sqlite3` module uses its :class:`Connection` class for the
+   connect call.  You can, however, subclass the :class:`Connection` class and make
+   :func:`connect` use your class instead by providing your class for the *factory*
+   parameter.
+
+   Consult the section :ref:`sqlite3-types` of this manual for details.
+
+   The :mod:`sqlite3` module internally uses a statement cache to avoid SQL parsing
+   overhead. If you want to explicitly set the number of statements that are cached
+   for the connection, you can set the *cached_statements* parameter. The currently
+   implemented default is to cache 100 statements.
+
+
+.. function:: register_converter(typename, callable)
+
+   Registers a callable to convert a bytestring from the database into a custom
+   Python type. The callable will be invoked for all database values that are of
+   the type *typename*. Confer the parameter *detect_types* of the :func:`connect`
+   function for how the type detection works. Note that the case of *typename* and
+   the name of the type in your query must match!
+
+
+.. function:: register_adapter(type, callable)
+
+   Registers a callable to convert the custom Python type *type* into one of
+   SQLite's supported types. The callable *callable* accepts as single parameter
+   the Python value, and must return a value of the following types: int, long,
+   float, str (UTF-8 encoded), unicode or buffer.
+
+
+.. function:: complete_statement(sql)
+
+   Returns :const:`True` if the string *sql* contains one or more complete SQL
+   statements terminated by semicolons. It does not verify that the SQL is
+   syntactically correct, only that there are no unclosed string literals and the
+   statement is terminated by a semicolon.
+
+   This can be used to build a shell for SQLite, as in the following example:
+
+
+   .. literalinclude:: ../includes/sqlite3/complete_statement.py
+
+
+.. function:: enable_callback_tracebacks(flag)
+
+   By default you will not get any tracebacks in user-defined functions,
+   aggregates, converters, authorizer callbacks etc. If you want to debug them, you
+   can call this function with *flag* as True. Afterwards, you will get tracebacks
+   from callbacks on ``sys.stderr``. Use :const:`False` to disable the feature
+   again.
+
+
+.. _sqlite3-connection-objects:
+
+Connection Objects
+------------------
+
+A :class:`Connection` instance has the following attributes and methods:
+
+.. attribute:: Connection.isolation_level
+
+   Get or set the current isolation level. None for autocommit mode or one of
+   "DEFERRED", "IMMEDIATE" or "EXLUSIVE". See section
+   :ref:`sqlite3-controlling-transactions` for a more detailed explanation.
+
+
+.. method:: Connection.cursor([cursorClass])
+
+   The cursor method accepts a single optional parameter *cursorClass*. If
+   supplied, this must be a custom cursor class that extends
+   :class:`sqlite3.Cursor`.
+
+
+.. method:: Connection.execute(sql, [parameters])
+
+   This is a nonstandard shortcut that creates an intermediate cursor object by
+   calling the cursor method, then calls the cursor's :meth:`execute` method with
+   the parameters given.
+
+
+.. method:: Connection.executemany(sql, [parameters])
+
+   This is a nonstandard shortcut that creates an intermediate cursor object by
+   calling the cursor method, then calls the cursor's :meth:`executemany` method
+   with the parameters given.
+
+
+.. method:: Connection.executescript(sql_script)
+
+   This is a nonstandard shortcut that creates an intermediate cursor object by
+   calling the cursor method, then calls the cursor's :meth:`executescript` method
+   with the parameters given.
+
+
+.. method:: Connection.create_function(name, num_params, func)
+
+   Creates a user-defined function that you can later use from within SQL
+   statements under the function name *name*. *num_params* is the number of
+   parameters the function accepts, and *func* is a Python callable that is called
+   as the SQL function.
+
+   The function can return any of the types supported by SQLite: unicode, str, int,
+   long, float, buffer and None.
+
+   Example:
+
+   .. literalinclude:: ../includes/sqlite3/md5func.py
+
+
+.. method:: Connection.create_aggregate(name, num_params, aggregate_class)
+
+   Creates a user-defined aggregate function.
+
+   The aggregate class must implement a ``step`` method, which accepts the number
+   of parameters *num_params*, and a ``finalize`` method which will return the
+   final result of the aggregate.
+
+   The ``finalize`` method can return any of the types supported by SQLite:
+   unicode, str, int, long, float, buffer and None.
+
+   Example:
+
+   .. literalinclude:: ../includes/sqlite3/mysumaggr.py
+
+
+.. method:: Connection.create_collation(name, callable)
+
+   Creates a collation with the specified *name* and *callable*. The callable will
+   be passed two string arguments. It should return -1 if the first is ordered
+   lower than the second, 0 if they are ordered equal and 1 if the first is ordered
+   higher than the second.  Note that this controls sorting (ORDER BY in SQL) so
+   your comparisons don't affect other SQL operations.
+
+   Note that the callable will get its parameters as Python bytestrings, which will
+   normally be encoded in UTF-8.
+
+   The following example shows a custom collation that sorts "the wrong way":
+
+   .. literalinclude:: ../includes/sqlite3/collation_reverse.py
+
+   To remove a collation, call ``create_collation`` with None as callable::
+
+      con.create_collation("reverse", None)
+
+
+.. method:: Connection.interrupt()
+
+   You can call this method from a different thread to abort any queries that might
+   be executing on the connection. The query will then abort and the caller will
+   get an exception.
+
+
+.. method:: Connection.set_authorizer(authorizer_callback)
+
+   This routine registers a callback. The callback is invoked for each attempt to
+   access a column of a table in the database. The callback should return
+   :const:`SQLITE_OK` if access is allowed, :const:`SQLITE_DENY` if the entire SQL
+   statement should be aborted with an error and :const:`SQLITE_IGNORE` if the
+   column should be treated as a NULL value. These constants are available in the
+   :mod:`sqlite3` module.
+
+   The first argument to the callback signifies what kind of operation is to be
+   authorized. The second and third argument will be arguments or :const:`None`
+   depending on the first argument. The 4th argument is the name of the database
+   ("main", "temp", etc.) if applicable. The 5th argument is the name of the
+   inner-most trigger or view that is responsible for the access attempt or
+   :const:`None` if this access attempt is directly from input SQL code.
+
+   Please consult the SQLite documentation about the possible values for the first
+   argument and the meaning of the second and third argument depending on the first
+   one. All necessary constants are available in the :mod:`sqlite3` module.
+
+
+.. attribute:: Connection.row_factory
+
+   You can change this attribute to a callable that accepts the cursor and the
+   original row as a tuple and will return the real result row.  This way, you can
+   implement more advanced ways of returning results, such  as returning an object
+   that can also access columns by name.
+
+   Example:
+
+   .. literalinclude:: ../includes/sqlite3/row_factory.py
+
+   If returning a tuple doesn't suffice and you want name-based access to
+   columns, you should consider setting :attr:`row_factory` to the
+   highly-optimized :class:`sqlite3.Row` type. :class:`Row` provides both
+   index-based and case-insensitive name-based access to columns with almost no
+   memory overhead. It will probably be better than your own custom
+   dictionary-based approach or even a db_row based solution.
+
+   .. % XXX what's a db_row-based solution?
+
+
+.. attribute:: Connection.text_factory
+
+   Using this attribute you can control what objects are returned for the TEXT data
+   type. By default, this attribute is set to :class:`unicode` and the
+   :mod:`sqlite3` module will return Unicode objects for TEXT. If you want to
+   return bytestrings instead, you can set it to :class:`str`.
+
+   For efficiency reasons, there's also a way to return Unicode objects only for
+   non-ASCII data, and bytestrings otherwise. To activate it, set this attribute to
+   :const:`sqlite3.OptimizedUnicode`.
+
+   You can also set it to any other callable that accepts a single bytestring
+   parameter and returns the resulting object.
+
+   See the following example code for illustration:
+
+   .. literalinclude:: ../includes/sqlite3/text_factory.py
+
+
+.. attribute:: Connection.total_changes
+
+   Returns the total number of database rows that have been modified, inserted, or
+   deleted since the database connection was opened.
+
+
+.. _sqlite3-cursor-objects:
+
+Cursor Objects
+--------------
+
+A :class:`Cursor` instance has the following attributes and methods:
+
+
+.. method:: Cursor.execute(sql, [parameters])
+
+   Executes a SQL statement. The SQL statement may be parametrized (i. e.
+   placeholders instead of SQL literals). The :mod:`sqlite3` module supports two
+   kinds of placeholders: question marks (qmark style) and named placeholders
+   (named style).
+
+   This example shows how to use parameters with qmark style:
+
+   .. literalinclude:: ../includes/sqlite3/execute_1.py
+
+   This example shows how to use the named style:
+
+   .. literalinclude:: ../includes/sqlite3/execute_2.py
+
+   :meth:`execute` will only execute a single SQL statement. If you try to execute
+   more than one statement with it, it will raise a Warning. Use
+   :meth:`executescript` if you want to execute multiple SQL statements with one
+   call.
+
+
+.. method:: Cursor.executemany(sql, seq_of_parameters)
+
+   Executes a SQL command against all parameter sequences or mappings found in the
+   sequence *sql*. The :mod:`sqlite3` module also allows using an iterator yielding
+   parameters instead of a sequence.
+
+   .. literalinclude:: ../includes/sqlite3/executemany_1.py
+
+   Here's a shorter example using a generator:
+
+   .. literalinclude:: ../includes/sqlite3/executemany_2.py
+
+
+.. method:: Cursor.executescript(sql_script)
+
+   This is a nonstandard convenience method for executing multiple SQL statements
+   at once. It issues a COMMIT statement first, then executes the SQL script it
+   gets as a parameter.
+
+   *sql_script* can be a bytestring or a Unicode string.
+
+   Example:
+
+   .. literalinclude:: ../includes/sqlite3/executescript.py
+
+
+.. attribute:: Cursor.rowcount
+
+   Although the :class:`Cursor` class of the :mod:`sqlite3` module implements this
+   attribute, the database engine's own support for the determination of "rows
+   affected"/"rows selected" is quirky.
+
+   For ``SELECT`` statements, :attr:`rowcount` is always None because we cannot
+   determine the number of rows a query produced until all rows were fetched.
+
+   For ``DELETE`` statements, SQLite reports :attr:`rowcount` as 0 if you make a
+   ``DELETE FROM table`` without any condition.
+
+   For :meth:`executemany` statements, the number of modifications are summed up
+   into :attr:`rowcount`.
+
+   As required by the Python DB API Spec, the :attr:`rowcount` attribute "is -1 in
+   case no executeXX() has been performed on the cursor or the rowcount of the last
+   operation is not determinable by the interface".
+
+
+.. _sqlite3-types:
+
+SQLite and Python types
+-----------------------
+
+
+Introduction
+^^^^^^^^^^^^
+
+SQLite natively supports the following types: NULL, INTEGER, REAL, TEXT, BLOB.
+
+The following Python types can thus be sent to SQLite without any problem:
+
++------------------------+-------------+
+| Python type            | SQLite type |
++========================+=============+
+| ``None``               | NULL        |
++------------------------+-------------+
+| ``int``                | INTEGER     |
++------------------------+-------------+
+| ``long``               | INTEGER     |
++------------------------+-------------+
+| ``float``              | REAL        |
++------------------------+-------------+
+| ``str (UTF8-encoded)`` | TEXT        |
++------------------------+-------------+
+| ``unicode``            | TEXT        |
++------------------------+-------------+
+| ``buffer``             | BLOB        |
++------------------------+-------------+
+
+This is how SQLite types are converted to Python types by default:
+
++-------------+---------------------------------------------+
+| SQLite type | Python type                                 |
++=============+=============================================+
+| ``NULL``    | None                                        |
++-------------+---------------------------------------------+
+| ``INTEGER`` | int or long, depending on size              |
++-------------+---------------------------------------------+
+| ``REAL``    | float                                       |
++-------------+---------------------------------------------+
+| ``TEXT``    | depends on text_factory, unicode by default |
++-------------+---------------------------------------------+
+| ``BLOB``    | buffer                                      |
++-------------+---------------------------------------------+
+
+The type system of the :mod:`sqlite3` module is extensible in two ways: you can
+store additional Python types in a SQLite database via object adaptation, and
+you can let the :mod:`sqlite3` module convert SQLite types to different Python
+types via converters.
+
+
+Using adapters to store additional Python types in SQLite databases
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+As described before, SQLite supports only a limited set of types natively. To
+use other Python types with SQLite, you must **adapt** them to one of the
+sqlite3 module's supported types for SQLite: one of NoneType, int, long, float,
+str, unicode, buffer.
+
+The :mod:`sqlite3` module uses Python object adaptation, as described in
+:pep:`246` for this.  The protocol to use is :class:`PrepareProtocol`.
+
+There are two ways to enable the :mod:`sqlite3` module to adapt a custom Python
+type to one of the supported ones.
+
+
+Letting your object adapt itself
+""""""""""""""""""""""""""""""""
+
+This is a good approach if you write the class yourself. Let's suppose you have
+a class like this::
+
+   class Point(object):
+       def __init__(self, x, y):
+           self.x, self.y = x, y
+
+Now you want to store the point in a single SQLite column.  First you'll have to
+choose one of the supported types first to be used for representing the point.
+Let's just use str and separate the coordinates using a semicolon. Then you need
+to give your class a method ``__conform__(self, protocol)`` which must return
+the converted value. The parameter *protocol* will be :class:`PrepareProtocol`.
+
+.. literalinclude:: ../includes/sqlite3/adapter_point_1.py
+
+
+Registering an adapter callable
+"""""""""""""""""""""""""""""""
+
+The other possibility is to create a function that converts the type to the
+string representation and register the function with :meth:`register_adapter`.
+
+.. note::
+
+   The type/class to adapt must be a new-style class, i. e. it must have
+   :class:`object` as one of its bases.
+
+.. literalinclude:: ../includes/sqlite3/adapter_point_2.py
+
+The :mod:`sqlite3` module has two default adapters for Python's built-in
+:class:`datetime.date` and :class:`datetime.datetime` types.  Now let's suppose
+we want to store :class:`datetime.datetime` objects not in ISO representation,
+but as a Unix timestamp.
+
+.. literalinclude:: ../includes/sqlite3/adapter_datetime.py
+
+
+Converting SQLite values to custom Python types
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Writing an adapter lets you send custom Python types to SQLite. But to make it
+really useful we need to make the Python to SQLite to Python roundtrip work.
+
+Enter converters.
+
+Let's go back to the :class:`Point` class. We stored the x and y coordinates
+separated via semicolons as strings in SQLite.
+
+First, we'll define a converter function that accepts the string as a parameter
+and constructs a :class:`Point` object from it.
+
+.. note::
+
+   Converter functions **always** get called with a string, no matter under which
+   data type you sent the value to SQLite.
+
+.. note::
+
+   Converter names are looked up in a case-sensitive manner.
+
+::
+
+   def convert_point(s):
+       x, y = map(float, s.split(";"))
+       return Point(x, y)
+
+Now you need to make the :mod:`sqlite3` module know that what you select from
+the database is actually a point. There are two ways of doing this:
+
+* Implicitly via the declared type
+
+* Explicitly via the column name
+
+Both ways are described in section :ref:`sqlite3-module-contents`, in the entries
+for the constants :const:`PARSE_DECLTYPES` and :const:`PARSE_COLNAMES`.
+
+The following example illustrates both approaches.
+
+.. literalinclude:: ../includes/sqlite3/converter_point.py
+
+
+Default adapters and converters
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+There are default adapters for the date and datetime types in the datetime
+module. They will be sent as ISO dates/ISO timestamps to SQLite.
+
+The default converters are registered under the name "date" for
+:class:`datetime.date` and under the name "timestamp" for
+:class:`datetime.datetime`.
+
+This way, you can use date/timestamps from Python without any additional
+fiddling in most cases. The format of the adapters is also compatible with the
+experimental SQLite date/time functions.
+
+The following example demonstrates this.
+
+.. literalinclude:: ../includes/sqlite3/pysqlite_datetime.py
+
+
+.. _sqlite3-controlling-transactions:
+
+Controlling Transactions
+------------------------
+
+By default, the :mod:`sqlite3` module opens transactions implicitly before a
+Data Modification Language (DML)  statement (i.e. INSERT/UPDATE/DELETE/REPLACE),
+and commits transactions implicitly before a non-DML, non-query statement (i. e.
+anything other than SELECT/INSERT/UPDATE/DELETE/REPLACE).
+
+So if you are within a transaction and issue a command like ``CREATE TABLE
+...``, ``VACUUM``, ``PRAGMA``, the :mod:`sqlite3` module will commit implicitly
+before executing that command. There are two reasons for doing that. The first
+is that some of these commands don't work within transactions. The other reason
+is that pysqlite needs to keep track of the transaction state (if a transaction
+is active or not).
+
+You can control which kind of "BEGIN" statements pysqlite implicitly executes
+(or none at all) via the *isolation_level* parameter to the :func:`connect`
+call, or via the :attr:`isolation_level` property of connections.
+
+If you want **autocommit mode**, then set :attr:`isolation_level` to None.
+
+Otherwise leave it at its default, which will result in a plain "BEGIN"
+statement, or set it to one of SQLite's supported isolation levels: DEFERRED,
+IMMEDIATE or EXCLUSIVE.
+
+As the :mod:`sqlite3` module needs to keep track of the transaction state, you
+should not use ``OR ROLLBACK`` or ``ON CONFLICT ROLLBACK`` in your SQL. Instead,
+catch the :exc:`IntegrityError` and call the :meth:`rollback` method of the
+connection yourself.
+
+
+Using pysqlite efficiently
+--------------------------
+
+
+Using shortcut methods
+^^^^^^^^^^^^^^^^^^^^^^
+
+Using the nonstandard :meth:`execute`, :meth:`executemany` and
+:meth:`executescript` methods of the :class:`Connection` object, your code can
+be written more concisely because you don't have to create the (often
+superfluous) :class:`Cursor` objects explicitly. Instead, the :class:`Cursor`
+objects are created implicitly and these shortcut methods return the cursor
+objects. This way, you can execute a SELECT statement and iterate over it
+directly using only a single call on the :class:`Connection` object.
+
+.. literalinclude:: ../includes/sqlite3/shortcut_methods.py
+
+
+Accessing columns by name instead of by index
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+One useful feature of the :mod:`sqlite3` module is the builtin
+:class:`sqlite3.Row` class designed to be used as a row factory.
+
+Rows wrapped with this class can be accessed both by index (like tuples) and
+case-insensitively by name:
+
+.. literalinclude:: ../includes/sqlite3/rowclass.py
+
diff --git a/Doc/library/stat.rst b/Doc/library/stat.rst
new file mode 100644
index 0000000..430bb23
--- /dev/null
+++ b/Doc/library/stat.rst
@@ -0,0 +1,167 @@
+
+:mod:`stat` --- Interpreting :func:`stat` results
+=================================================
+
+.. module:: stat
+   :synopsis: Utilities for interpreting the results of os.stat(), os.lstat() and os.fstat().
+.. sectionauthor:: Skip Montanaro <skip@automatrix.com>
+
+
+The :mod:`stat` module defines constants and functions for interpreting the
+results of :func:`os.stat`, :func:`os.fstat` and :func:`os.lstat` (if they
+exist).  For complete details about the :cfunc:`stat`, :cfunc:`fstat` and
+:cfunc:`lstat` calls, consult the documentation for your system.
+
+The :mod:`stat` module defines the following functions to test for specific file
+types:
+
+
+.. function:: S_ISDIR(mode)
+
+   Return non-zero if the mode is from a directory.
+
+
+.. function:: S_ISCHR(mode)
+
+   Return non-zero if the mode is from a character special device file.
+
+
+.. function:: S_ISBLK(mode)
+
+   Return non-zero if the mode is from a block special device file.
+
+
+.. function:: S_ISREG(mode)
+
+   Return non-zero if the mode is from a regular file.
+
+
+.. function:: S_ISFIFO(mode)
+
+   Return non-zero if the mode is from a FIFO (named pipe).
+
+
+.. function:: S_ISLNK(mode)
+
+   Return non-zero if the mode is from a symbolic link.
+
+
+.. function:: S_ISSOCK(mode)
+
+   Return non-zero if the mode is from a socket.
+
+Two additional functions are defined for more general manipulation of the file's
+mode:
+
+
+.. function:: S_IMODE(mode)
+
+   Return the portion of the file's mode that can be set by :func:`os.chmod`\
+   ---that is, the file's permission bits, plus the sticky bit, set-group-id, and
+   set-user-id bits (on systems that support them).
+
+
+.. function:: S_IFMT(mode)
+
+   Return the portion of the file's mode that describes the file type (used by the
+   :func:`S_IS\*` functions above).
+
+Normally, you would use the :func:`os.path.is\*` functions for testing the type
+of a file; the functions here are useful when you are doing multiple tests of
+the same file and wish to avoid the overhead of the :cfunc:`stat` system call
+for each test.  These are also useful when checking for information about a file
+that isn't handled by :mod:`os.path`, like the tests for block and character
+devices.
+
+All the variables below are simply symbolic indexes into the 10-tuple returned
+by :func:`os.stat`, :func:`os.fstat` or :func:`os.lstat`.
+
+
+.. data:: ST_MODE
+
+   Inode protection mode.
+
+
+.. data:: ST_INO
+
+   Inode number.
+
+
+.. data:: ST_DEV
+
+   Device inode resides on.
+
+
+.. data:: ST_NLINK
+
+   Number of links to the inode.
+
+
+.. data:: ST_UID
+
+   User id of the owner.
+
+
+.. data:: ST_GID
+
+   Group id of the owner.
+
+
+.. data:: ST_SIZE
+
+   Size in bytes of a plain file; amount of data waiting on some special files.
+
+
+.. data:: ST_ATIME
+
+   Time of last access.
+
+
+.. data:: ST_MTIME
+
+   Time of last modification.
+
+
+.. data:: ST_CTIME
+
+   The "ctime" as reported by the operating system.  On some systems (like Unix) is
+   the time of the last metadata change, and, on others (like Windows), is the
+   creation time (see platform documentation for details).
+
+The interpretation of "file size" changes according to the file type.  For plain
+files this is the size of the file in bytes.  For FIFOs and sockets under most
+flavors of Unix (including Linux in particular), the "size" is the number of
+bytes waiting to be read at the time of the call to :func:`os.stat`,
+:func:`os.fstat`, or :func:`os.lstat`; this can sometimes be useful, especially
+for polling one of these special files after a non-blocking open.  The meaning
+of the size field for other character and block devices varies more, depending
+on the implementation of the underlying system call.
+
+Example::
+
+   import os, sys
+   from stat import *
+
+   def walktree(top, callback):
+       '''recursively descend the directory tree rooted at top,
+          calling the callback function for each regular file'''
+
+       for f in os.listdir(top):
+           pathname = os.path.join(top, f)
+           mode = os.stat(pathname)[ST_MODE]
+           if S_ISDIR(mode):
+               # It's a directory, recurse into it
+               walktree(pathname, callback)
+           elif S_ISREG(mode):
+               # It's a file, call the callback function
+               callback(pathname)
+           else:
+               # Unknown file type, print a message
+               print 'Skipping %s' % pathname
+
+   def visitfile(file):
+       print 'visiting', file
+
+   if __name__ == '__main__':
+       walktree(sys.argv[1], visitfile)
+
diff --git a/Doc/library/statvfs.rst b/Doc/library/statvfs.rst
new file mode 100644
index 0000000..6ec7c38
--- /dev/null
+++ b/Doc/library/statvfs.rst
@@ -0,0 +1,67 @@
+
+:mod:`statvfs` --- Constants used with :func:`os.statvfs`
+=========================================================
+
+.. module:: statvfs
+   :synopsis: Constants for interpreting the result of os.statvfs().
+.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
+
+
+.. % LaTeX'ed from comments in module
+
+The :mod:`statvfs` module defines constants so interpreting the result if
+:func:`os.statvfs`, which returns a tuple, can be made without remembering
+"magic numbers."  Each of the constants defined in this module is the *index* of
+the entry in the tuple returned by :func:`os.statvfs` that contains the
+specified information.
+
+
+.. data:: F_BSIZE
+
+   Preferred file system block size.
+
+
+.. data:: F_FRSIZE
+
+   Fundamental file system block size.
+
+
+.. data:: F_BLOCKS
+
+   Total number of blocks in the filesystem.
+
+
+.. data:: F_BFREE
+
+   Total number of free blocks.
+
+
+.. data:: F_BAVAIL
+
+   Free blocks available to non-super user.
+
+
+.. data:: F_FILES
+
+   Total number of file nodes.
+
+
+.. data:: F_FFREE
+
+   Total number of free file nodes.
+
+
+.. data:: F_FAVAIL
+
+   Free nodes available to non-super user.
+
+
+.. data:: F_FLAG
+
+   Flags. System dependent: see :cfunc:`statvfs` man page.
+
+
+.. data:: F_NAMEMAX
+
+   Maximum file name length.
+
diff --git a/Doc/library/stdtypes.rst b/Doc/library/stdtypes.rst
new file mode 100644
index 0000000..34c943c
--- /dev/null
+++ b/Doc/library/stdtypes.rst
@@ -0,0 +1,2409 @@
+.. XXX: reference/datamodel and this have quite a few overlaps!
+
+
+.. _bltin-types:
+
+**************
+Built-in Types
+**************
+
+The following sections describe the standard types that are built into the
+interpreter.
+
+.. note::
+
+   Historically (until release 2.2), Python's built-in types have differed from
+   user-defined types because it was not possible to use the built-in types as the
+   basis for object-oriented inheritance. This limitation no longer
+   exists.
+
+.. index:: pair: built-in; types
+
+The principal built-in types are numerics, sequences, mappings, files, classes,
+instances and exceptions.
+
+.. index:: statement: print
+
+Some operations are supported by several object types; in particular,
+practically all objects can be compared, tested for truth value, and converted
+to a string (with the :func:`repr` function or the slightly different
+:func:`str` function).  The latter function is implicitly used when an object is
+written by the :func:`print` function.
+
+
+.. _truth:
+
+Truth Value Testing
+===================
+
+.. index::
+   statement: if
+   statement: while
+   pair: truth; value
+   pair: Boolean; operations
+   single: false
+
+Any object can be tested for truth value, for use in an :keyword:`if` or
+:keyword:`while` condition or as operand of the Boolean operations below. The
+following values are considered false:
+
+  .. index:: single: None (Built-in object)
+
+* ``None``
+
+  .. index:: single: False (Built-in object)
+
+* ``False``
+
+* zero of any numeric type, for example, ``0``, ``0L``, ``0.0``, ``0j``.
+
+* any empty sequence, for example, ``''``, ``()``, ``[]``.
+
+* any empty mapping, for example, ``{}``.
+
+* instances of user-defined classes, if the class defines a :meth:`__bool__` or
+  :meth:`__len__` method, when that method returns the integer zero or
+  :class:`bool` value ``False``. [#]_
+
+.. index:: single: true
+
+All other values are considered true --- so objects of many types are always
+true.
+
+.. index::
+   operator: or
+   operator: and
+   single: False
+   single: True
+
+Operations and built-in functions that have a Boolean result always return ``0``
+or ``False`` for false and ``1`` or ``True`` for true, unless otherwise stated.
+(Important exception: the Boolean operations ``or`` and ``and`` always return
+one of their operands.)
+
+
+.. _boolean:
+
+Boolean Operations --- :keyword:`and`, :keyword:`or`, :keyword:`not`
+====================================================================
+
+.. index:: pair: Boolean; operations
+
+These are the Boolean operations, ordered by ascending priority:
+
++-------------+---------------------------------+-------+
+| Operation   | Result                          | Notes |
++=============+=================================+=======+
+| ``x or y``  | if *x* is false, then *y*, else | \(1)  |
+|             | *x*                             |       |
++-------------+---------------------------------+-------+
+| ``x and y`` | if *x* is false, then *x*, else | \(2)  |
+|             | *y*                             |       |
++-------------+---------------------------------+-------+
+| ``not x``   | if *x* is false, then ``True``, | \(3)  |
+|             | else ``False``                  |       |
++-------------+---------------------------------+-------+
+
+.. index::
+   operator: and
+   operator: or
+   operator: not
+
+Notes:
+
+(1)
+   This is a short-circuit operator, so it only evaluates the second
+   argument if the first one is :const:`False`.
+
+(2)
+   This is a short-circuit operator, so it only evaluates the second
+   argument if the first one is :const:`True`.
+
+(3)
+   ``not`` has a lower priority than non-Boolean operators, so ``not a == b`` is
+   interpreted as ``not (a == b)``, and ``a == not b`` is a syntax error.
+
+
+.. _stdcomparisons:
+
+Comparisons
+===========
+
+.. index:: pair: chaining; comparisons
+
+Comparison operations are supported by all objects.  They all have the same
+priority (which is higher than that of the Boolean operations). Comparisons can
+be chained arbitrarily; for example, ``x < y <= z`` is equivalent to ``x < y and
+y <= z``, except that *y* is evaluated only once (but in both cases *z* is not
+evaluated at all when ``x < y`` is found to be false).
+
+This table summarizes the comparison operations:
+
++------------+-------------------------+-------+
+| Operation  | Meaning                 | Notes |
++============+=========================+=======+
+| ``<``      | strictly less than      |       |
++------------+-------------------------+-------+
+| ``<=``     | less than or equal      |       |
++------------+-------------------------+-------+
+| ``>``      | strictly greater than   |       |
++------------+-------------------------+-------+
+| ``>=``     | greater than or equal   |       |
++------------+-------------------------+-------+
+| ``==``     | equal                   |       |
++------------+-------------------------+-------+
+| ``!=``     | not equal               |       |
++------------+-------------------------+-------+
+| ``is``     | object identity         |       |
++------------+-------------------------+-------+
+| ``is not`` | negated object identity |       |
++------------+-------------------------+-------+
+
+.. index::
+   pair: operator; comparison
+   operator: ==
+   operator: is
+   operator: is not
+
+.. % XXX *All* others have funny characters < ! >
+
+.. index::
+   pair: object; numeric
+   pair: objects; comparing
+
+Objects of different types, except different numeric types and different string
+types, never compare equal; such objects are ordered consistently but
+arbitrarily (so that sorting a heterogeneous array yields a consistent result).
+Furthermore, some types (for example, file objects) support only a degenerate
+notion of comparison where any two objects of that type are unequal.  Again,
+such objects are ordered arbitrarily but consistently. The ``<``, ``<=``, ``>``
+and ``>=`` operators will raise a :exc:`TypeError` exception when any operand is
+a complex number.
+
+.. index:: single: __cmp__() (instance method)
+
+Instances of a class normally compare as non-equal unless the class defines the
+:meth:`__cmp__` method.  Refer to :ref:`customization`) for information on the
+use of this method to effect object comparisons.
+
+**Implementation note:** Objects of different types except numbers are ordered
+by their type names; objects of the same types that don't support proper
+comparison are ordered by their address.
+
+.. index::
+   operator: in
+   operator: not in
+
+Two more operations with the same syntactic priority, ``in`` and ``not in``, are
+supported only by sequence types (below).
+
+
+.. _typesnumeric:
+
+Numeric Types --- :class:`int`, :class:`float`, :class:`long`, :class:`complex`
+===============================================================================
+
+.. index::
+   object: numeric
+   object: Boolean
+   object: integer
+   object: long integer
+   object: floating point
+   object: complex number
+   pair: C; language
+
+There are four distinct numeric types: :dfn:`plain integers`, :dfn:`long
+integers`,  :dfn:`floating point numbers`, and :dfn:`complex numbers`. In
+addition, Booleans are a subtype of plain integers. Plain integers (also just
+called :dfn:`integers`) are implemented using :ctype:`long` in C, which gives
+them at least 32 bits of precision (``sys.maxint`` is always set to the maximum
+plain integer value for the current platform, the minimum value is
+``-sys.maxint - 1``).  Long integers have unlimited precision. Floating point
+numbers are implemented using :ctype:`double` in C. All bets on their precision
+are off unless you happen to know the machine you are working with.
+
+Complex numbers have a real and imaginary part, which are each implemented using
+:ctype:`double` in C.  To extract these parts from a complex number *z*, use
+``z.real`` and ``z.imag``.
+
+.. index::
+   pair: numeric; literals
+   pair: integer; literals
+   triple: long; integer; literals
+   pair: floating point; literals
+   pair: complex number; literals
+   pair: hexadecimal; literals
+   pair: octal; literals
+
+Numbers are created by numeric literals or as the result of built-in functions
+and operators.  Unadorned integer literals (including hex and octal numbers)
+yield plain integers unless the value they denote is too large to be represented
+as a plain integer, in which case they yield a long integer.  Integer literals
+with an ``'L'`` or ``'l'`` suffix yield long integers (``'L'`` is preferred
+because ``1l`` looks too much like eleven!).  Numeric literals containing a
+decimal point or an exponent sign yield floating point numbers.  Appending
+``'j'`` or ``'J'`` to a numeric literal yields a complex number with a zero real
+part. A complex numeric literal is the sum of a real and an imaginary part.
+
+.. index::
+   single: arithmetic
+   builtin: int
+   builtin: long
+   builtin: float
+   builtin: complex
+
+Python fully supports mixed arithmetic: when a binary arithmetic operator has
+operands of different numeric types, the operand with the "narrower" type is
+widened to that of the other, where plain integer is narrower than long integer
+is narrower than floating point is narrower than complex. Comparisons between
+numbers of mixed type use the same rule. [#]_ The constructors :func:`int`,
+:func:`long`, :func:`float`, and :func:`complex` can be used to produce numbers
+of a specific type.
+
+All numeric types (except complex) support the following operations, sorted by
+ascending priority (operations in the same box have the same priority; all
+numeric operations have a higher priority than comparison operations):
+
++--------------------+---------------------------------+--------+
+| Operation          | Result                          | Notes  |
++====================+=================================+========+
+| ``x + y``          | sum of *x* and *y*              |        |
++--------------------+---------------------------------+--------+
+| ``x - y``          | difference of *x* and *y*       |        |
++--------------------+---------------------------------+--------+
+| ``x * y``          | product of *x* and *y*          |        |
++--------------------+---------------------------------+--------+
+| ``x / y``          | quotient of *x* and *y*         | \(1)   |
++--------------------+---------------------------------+--------+
+| ``x // y``         | (floored) quotient of *x* and   | \(5)   |
+|                    | *y*                             |        |
++--------------------+---------------------------------+--------+
+| ``x % y``          | remainder of ``x / y``          | \(4)   |
++--------------------+---------------------------------+--------+
+| ``-x``             | *x* negated                     |        |
++--------------------+---------------------------------+--------+
+| ``+x``             | *x* unchanged                   |        |
++--------------------+---------------------------------+--------+
+| ``abs(x)``         | absolute value or magnitude of  |        |
+|                    | *x*                             |        |
++--------------------+---------------------------------+--------+
+| ``int(x)``         | *x* converted to integer        | \(2)   |
++--------------------+---------------------------------+--------+
+| ``long(x)``        | *x* converted to long integer   | \(2)   |
++--------------------+---------------------------------+--------+
+| ``float(x)``       | *x* converted to floating point |        |
++--------------------+---------------------------------+--------+
+| ``complex(re,im)`` | a complex number with real part |        |
+|                    | *re*, imaginary part *im*.      |        |
+|                    | *im* defaults to zero.          |        |
++--------------------+---------------------------------+--------+
+| ``c.conjugate()``  | conjugate of the complex number |        |
+|                    | *c*                             |        |
++--------------------+---------------------------------+--------+
+| ``divmod(x, y)``   | the pair ``(x // y, x % y)``    | (3)(4) |
++--------------------+---------------------------------+--------+
+| ``pow(x, y)``      | *x* to the power *y*            |        |
++--------------------+---------------------------------+--------+
+| ``x ** y``         | *x* to the power *y*            |        |
++--------------------+---------------------------------+--------+
+
+.. index::
+   triple: operations on; numeric; types
+   single: conjugate() (complex number method)
+
+Notes:
+
+(1)
+   .. index::
+      pair: integer; division
+      triple: long; integer; division
+
+   For (plain or long) integer division, the result is an integer. The result is
+   always rounded towards minus infinity: 1/2 is 0, (-1)/2 is -1, 1/(-2) is -1, and
+   (-1)/(-2) is 0.  Note that the result is a long integer if either operand is a
+   long integer, regardless of the numeric value.
+
+(2)
+   .. index::
+      module: math
+      single: floor() (in module math)
+      single: ceil() (in module math)
+      pair: numeric; conversions
+      pair: C; language
+
+   Conversion from floating point to (long or plain) integer may round or truncate
+   as in C; see functions :func:`floor` and :func:`ceil` in the :mod:`math` module
+   for well-defined conversions.
+
+(3)
+   See :ref:`built-in-funcs` for a full description.
+
+(4)
+   Complex floor division operator, modulo operator, and :func:`divmod`.
+
+   .. deprecated:: 2.3
+      Instead convert to float using :func:`abs` if appropriate.
+
+(5)
+   Also referred to as integer division.  The resultant value is a whole integer,
+   though the result's type is not necessarily int.
+
+.. % XXXJH exceptions: overflow (when? what operations?) zerodivision
+
+
+.. _bitstring-ops:
+
+Bit-string Operations on Integer Types
+--------------------------------------
+
+.. _bit-string-operations:
+
+Plain and long integer types support additional operations that make sense only
+for bit-strings.  Negative numbers are treated as their 2's complement value
+(for long integers, this assumes a sufficiently large number of bits that no
+overflow occurs during the operation).
+
+The priorities of the binary bit-wise operations are all lower than the numeric
+operations and higher than the comparisons; the unary operation ``~`` has the
+same priority as the other unary numeric operations (``+`` and ``-``).
+
+This table lists the bit-string operations sorted in ascending priority
+(operations in the same box have the same priority):
+
++------------+--------------------------------+----------+
+| Operation  | Result                         | Notes    |
++============+================================+==========+
+| ``x | y``  | bitwise :dfn:`or` of *x* and   |          |
+|            | *y*                            |          |
++------------+--------------------------------+----------+
+| ``x ^ y``  | bitwise :dfn:`exclusive or` of |          |
+|            | *x* and *y*                    |          |
++------------+--------------------------------+----------+
+| ``x & y``  | bitwise :dfn:`and` of *x* and  |          |
+|            | *y*                            |          |
++------------+--------------------------------+----------+
+| ``x << n`` | *x* shifted left by *n* bits   | (1), (2) |
++------------+--------------------------------+----------+
+| ``x >> n`` | *x* shifted right by *n* bits  | (1), (3) |
++------------+--------------------------------+----------+
+| ``~x``     | the bits of *x* inverted       |          |
++------------+--------------------------------+----------+
+
+.. index::
+   triple: operations on; integer; types
+   pair: bit-string; operations
+   pair: shifting; operations
+   pair: masking; operations
+
+Notes:
+
+(1)
+   Negative shift counts are illegal and cause a :exc:`ValueError` to be raised.
+
+(2)
+   A left shift by *n* bits is equivalent to multiplication by ``pow(2, n)``
+   without overflow check.
+
+(3)
+   A right shift by *n* bits is equivalent to division by ``pow(2, n)`` without
+   overflow check.
+
+
+.. _typeiter:
+
+Iterator Types
+==============
+
+.. versionadded:: 2.2
+
+.. index::
+   single: iterator protocol
+   single: protocol; iterator
+   single: sequence; iteration
+   single: container; iteration over
+
+Python supports a concept of iteration over containers.  This is implemented
+using two distinct methods; these are used to allow user-defined classes to
+support iteration.  Sequences, described below in more detail, always support
+the iteration methods.
+
+One method needs to be defined for container objects to provide iteration
+support:
+
+
+.. method:: container.__iter__()
+
+   Return an iterator object.  The object is required to support the iterator
+   protocol described below.  If a container supports different types of
+   iteration, additional methods can be provided to specifically request
+   iterators for those iteration types.  (An example of an object supporting
+   multiple forms of iteration would be a tree structure which supports both
+   breadth-first and depth-first traversal.)  This method corresponds to the
+   :attr:`tp_iter` slot of the type structure for Python objects in the Python/C
+   API.
+
+The iterator objects themselves are required to support the following two
+methods, which together form the :dfn:`iterator protocol`:
+
+
+.. method:: iterator.__iter__()
+
+   Return the iterator object itself.  This is required to allow both containers
+   and iterators to be used with the :keyword:`for` and :keyword:`in` statements.
+   This method corresponds to the :attr:`tp_iter` slot of the type structure for
+   Python objects in the Python/C API.
+
+
+.. method:: iterator.next()
+
+   Return the next item from the container.  If there are no further items, raise
+   the :exc:`StopIteration` exception.  This method corresponds to the
+   :attr:`tp_iternext` slot of the type structure for Python objects in the
+   Python/C API.
+
+Python defines several iterator objects to support iteration over general and
+specific sequence types, dictionaries, and other more specialized forms.  The
+specific types are not important beyond their implementation of the iterator
+protocol.
+
+The intention of the protocol is that once an iterator's :meth:`__next__` method
+raises :exc:`StopIteration`, it will continue to do so on subsequent calls.
+Implementations that do not obey this property are deemed broken.  (This
+constraint was added in Python 2.3; in Python 2.2, various iterators are broken
+according to this rule.)
+
+Python's generators provide a convenient way to implement the iterator protocol.
+If a container object's :meth:`__iter__` method is implemented as a generator,
+it will automatically return an iterator object (technically, a generator
+object) supplying the :meth:`__iter__` and :meth:`__next__` methods.
+
+
+.. _typesseq:
+
+Sequence Types --- :class:`str`, :class:`unicode`, :class:`list`, :class:`tuple`, :class:`buffer`, :class:`range`
+=================================================================================================================
+
+There are six sequence types: strings, Unicode strings, lists, tuples, buffers,
+and range objects.
+(For other containers see the built in :class:`dict`, :class:`list`,
+:class:`set`, and :class:`tuple` classes, and the :mod:`collections`
+module.)
+  
+
+.. index::
+   object: sequence
+   object: string
+   object: tuple
+   object: list
+   object: buffer
+   object: range
+
+String literals are written in single or double quotes: ``'xyzzy'``,
+``"frobozz"``.  See :ref:`strings` for more about string literals.  In addition
+to the functionality described here, there are also string-specific methods
+described in the :ref:`string-methods` section.  Lists are constructed with
+square brackets, separating items with commas: ``[a, b, c]``.  Tuples are
+constructed by the comma operator (not within square brackets), with or without
+enclosing parentheses, but an empty tuple must have the enclosing parentheses,
+such as ``a, b, c`` or ``()``.  A single item tuple must have a trailing comma,
+such as ``(d,)``.
+
+Buffer objects are not directly supported by Python syntax, but can be created
+by calling the builtin function :func:`buffer`.  They don't support
+concatenation or repetition.
+
+Objects of type range are similar to buffers in that there is no specific syntax to
+create them, but they are created using the :func:`range` function.  They don't
+support slicing, concatenation or repetition, and using ``in``, ``not in``,
+:func:`min` or :func:`max` on them is inefficient.
+
+Most sequence types support the following operations.  The ``in`` and ``not in``
+operations have the same priorities as the comparison operations.  The ``+`` and
+``*`` operations have the same priority as the corresponding numeric operations.
+[#]_
+
+This table lists the sequence operations sorted in ascending priority
+(operations in the same box have the same priority).  In the table, *s* and *t*
+are sequences of the same type; *n*, *i* and *j* are integers:
+
++------------------+--------------------------------+----------+
+| Operation        | Result                         | Notes    |
++==================+================================+==========+
+| ``x in s``       | ``True`` if an item of *s* is  | \(1)     |
+|                  | equal to *x*, else ``False``   |          |
++------------------+--------------------------------+----------+
+| ``x not in s``   | ``False`` if an item of *s* is | \(1)     |
+|                  | equal to *x*, else ``True``    |          |
++------------------+--------------------------------+----------+
+| ``s + t``        | the concatenation of *s* and   | \(6)     |
+|                  | *t*                            |          |
++------------------+--------------------------------+----------+
+| ``s * n, n * s`` | *n* shallow copies of *s*      | \(2)     |
+|                  | concatenated                   |          |
++------------------+--------------------------------+----------+
+| ``s[i]``         | *i*'th item of *s*, origin 0   | \(3)     |
++------------------+--------------------------------+----------+
+| ``s[i:j]``       | slice of *s* from *i* to *j*   | (3), (4) |
++------------------+--------------------------------+----------+
+| ``s[i:j:k]``     | slice of *s* from *i* to *j*   | (3), (5) |
+|                  | with step *k*                  |          |
++------------------+--------------------------------+----------+
+| ``len(s)``       | length of *s*                  |          |
++------------------+--------------------------------+----------+
+| ``min(s)``       | smallest item of *s*           |          |
++------------------+--------------------------------+----------+
+| ``max(s)``       | largest item of *s*            |          |
++------------------+--------------------------------+----------+
+
+Sequence types also support comparisons. In particular, tuples and lists
+are compared lexicographically by comparing corresponding
+elements. This means that to compare equal, every element must compare
+equal and the two sequences must be of the same type and have the same
+length. (For full details see :ref:`comparisons` in the language
+reference.)
+
+.. index::
+   triple: operations on; sequence; types
+   builtin: len
+   builtin: min
+   builtin: max
+   pair: concatenation; operation
+   pair: repetition; operation
+   pair: subscript; operation
+   pair: slice; operation
+   pair: extended slice; operation
+   operator: in
+   operator: not in
+
+Notes:
+
+(1)
+   When *s* is a string or Unicode string object the ``in`` and ``not in``
+   operations act like a substring test.  In Python versions before 2.3, *x* had to
+   be a string of length 1. In Python 2.3 and beyond, *x* may be a string of any
+   length.
+
+(2)
+   Values of *n* less than ``0`` are treated as ``0`` (which yields an empty
+   sequence of the same type as *s*).  Note also that the copies are shallow;
+   nested structures are not copied.  This often haunts new Python programmers;
+   consider::
+
+      >>> lists = [[]] * 3
+      >>> lists
+      [[], [], []]
+      >>> lists[0].append(3)
+      >>> lists
+      [[3], [3], [3]]
+
+   What has happened is that ``[[]]`` is a one-element list containing an empty
+   list, so all three elements of ``[[]] * 3`` are (pointers to) this single empty
+   list.  Modifying any of the elements of ``lists`` modifies this single list.
+   You can create a list of different lists this way::
+
+      >>> lists = [[] for i in range(3)]
+      >>> lists[0].append(3)
+      >>> lists[1].append(5)
+      >>> lists[2].append(7)
+      >>> lists
+      [[3], [5], [7]]
+
+(3)
+   If *i* or *j* is negative, the index is relative to the end of the string:
+   ``len(s) + i`` or ``len(s) + j`` is substituted.  But note that ``-0`` is still
+   ``0``.
+
+(4)
+   The slice of *s* from *i* to *j* is defined as the sequence of items with index
+   *k* such that ``i <= k < j``.  If *i* or *j* is greater than ``len(s)``, use
+   ``len(s)``.  If *i* is omitted or ``None``, use ``0``.  If *j* is omitted or
+   ``None``, use ``len(s)``.  If *i* is greater than or equal to *j*, the slice is
+   empty.
+
+(5)
+   The slice of *s* from *i* to *j* with step *k* is defined as the sequence of
+   items with index  ``x = i + n*k`` such that 0 ≤n < (j-i)/(k).  In other words,
+   the indices are ``i``, ``i+k``, ``i+2*k``, ``i+3*k`` and so on, stopping when
+   *j* is reached (but never including *j*).  If *i* or *j* is greater than
+   ``len(s)``, use ``len(s)``.  If *i* or *j* are omitted or ``None``, they become
+   "end" values (which end depends on the sign of *k*).  Note, *k* cannot be zero.
+   If *k* is ``None``, it is treated like ``1``.
+
+(6)
+   If *s* and *t* are both strings, some Python implementations such as CPython can
+   usually perform an in-place optimization for assignments of the form ``s=s+t``
+   or ``s+=t``.  When applicable, this optimization makes quadratic run-time much
+   less likely.  This optimization is both version and implementation dependent.
+   For performance sensitive code, it is preferable to use the :meth:`str.join`
+   method which assures consistent linear concatenation performance across versions
+   and implementations.
+
+   .. versionchanged:: 2.4
+      Formerly, string concatenation never occurred in-place.
+
+
+.. _string-methods:
+
+String Methods
+--------------
+
+.. index:: pair: string; methods
+
+Below are listed the string methods which both 8-bit strings and Unicode objects
+support. In addition, Python's strings support the sequence type methods
+described in the :ref:`typesseq` section. To output formatted strings
+use template strings or the ``%`` operator described in the
+:ref:`string-formatting` section. Also, see the :mod:`re` module for
+string functions based on regular expressions.
+
+.. method:: str.capitalize()
+
+   Return a copy of the string with only its first character capitalized.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.center(width[, fillchar])
+
+   Return centered in a string of length *width*. Padding is done using the
+   specified *fillchar* (default is a space).
+
+   .. versionchanged:: 2.4
+      Support for the *fillchar* argument.
+
+
+.. method:: str.count(sub[, start[, end]])
+
+   Return the number of occurrences of substring *sub* in string S\
+   ``[start:end]``.  Optional arguments *start* and *end* are interpreted as in
+   slice notation.
+
+
+.. method:: str.decode([encoding[, errors]])
+
+   Decodes the string using the codec registered for *encoding*. *encoding*
+   defaults to the default string encoding.  *errors* may be given to set a
+   different error handling scheme.  The default is ``'strict'``, meaning that
+   encoding errors raise :exc:`UnicodeError`.  Other possible values are
+   ``'ignore'``, ``'replace'`` and any other name registered via
+   :func:`codecs.register_error`, see section :ref:`codec-base-classes`.
+
+   .. versionadded:: 2.2
+
+   .. versionchanged:: 2.3
+      Support for other error handling schemes added.
+
+
+.. method:: str.encode([encoding[,errors]])
+
+   Return an encoded version of the string.  Default encoding is the current
+   default string encoding.  *errors* may be given to set a different error
+   handling scheme.  The default for *errors* is ``'strict'``, meaning that
+   encoding errors raise a :exc:`UnicodeError`.  Other possible values are
+   ``'ignore'``, ``'replace'``, ``'xmlcharrefreplace'``, ``'backslashreplace'`` and
+   any other name registered via :func:`codecs.register_error`, see section
+   :ref:`codec-base-classes`. For a list of possible encodings, see section
+   :ref:`standard-encodings`.
+
+   .. versionadded:: 2.0
+
+   .. versionchanged:: 2.3
+      Support for ``'xmlcharrefreplace'`` and ``'backslashreplace'`` and other error
+      handling schemes added.
+
+
+.. method:: str.endswith(suffix[, start[, end]])
+
+   Return ``True`` if the string ends with the specified *suffix*, otherwise return
+   ``False``.  *suffix* can also be a tuple of suffixes to look for.  With optional
+   *start*, test beginning at that position.  With optional *end*, stop comparing
+   at that position.
+
+   .. versionchanged:: 2.5
+      Accept tuples as *suffix*.
+
+
+.. method:: str.expandtabs([tabsize])
+
+   Return a copy of the string where all tab characters are expanded using spaces.
+   If *tabsize* is not given, a tab size of ``8`` characters is assumed.
+
+
+.. method:: str.find(sub[, start[, end]])
+
+   Return the lowest index in the string where substring *sub* is found, such that
+   *sub* is contained in the range [*start*, *end*].  Optional arguments *start*
+   and *end* are interpreted as in slice notation.  Return ``-1`` if *sub* is not
+   found.
+
+
+.. method:: str.index(sub[, start[, end]])
+
+   Like :meth:`find`, but raise :exc:`ValueError` when the substring is not found.
+
+
+.. method:: str.isalnum()
+
+   Return true if all characters in the string are alphanumeric and there is at
+   least one character, false otherwise.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.isalpha()
+
+   Return true if all characters in the string are alphabetic and there is at least
+   one character, false otherwise.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.isdigit()
+
+   Return true if all characters in the string are digits and there is at least one
+   character, false otherwise.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.isidentifier()
+
+   Return true if the string is a valid identifier according to the language
+   definition.
+
+   .. XXX link to the definition?
+
+
+.. method:: str.islower()
+
+   Return true if all cased characters in the string are lowercase and there is at
+   least one cased character, false otherwise.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.isspace()
+
+   Return true if there are only whitespace characters in the string and there is
+   at least one character, false otherwise.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.istitle()
+
+   Return true if the string is a titlecased string and there is at least one
+   character, for example uppercase characters may only follow uncased characters
+   and lowercase characters only cased ones.  Return false otherwise.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.isupper()
+
+   Return true if all cased characters in the string are uppercase and there is at
+   least one cased character, false otherwise.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.join(seq)
+
+   Return a string which is the concatenation of the strings in the sequence *seq*.
+   The separator between elements is the string providing this method.
+
+
+.. method:: str.ljust(width[, fillchar])
+
+   Return the string left justified in a string of length *width*. Padding is done
+   using the specified *fillchar* (default is a space).  The original string is
+   returned if *width* is less than ``len(s)``.
+
+   .. versionchanged:: 2.4
+      Support for the *fillchar* argument.
+
+
+.. method:: str.lower()
+
+   Return a copy of the string converted to lowercase.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.lstrip([chars])
+
+   Return a copy of the string with leading characters removed.  The *chars*
+   argument is a string specifying the set of characters to be removed.  If omitted
+   or ``None``, the *chars* argument defaults to removing whitespace.  The *chars*
+   argument is not a prefix; rather, all combinations of its values are stripped::
+
+      >>> '   spacious   '.lstrip()
+      'spacious   '
+      >>> 'www.example.com'.lstrip('cmowz.')
+      'example.com'
+
+   .. versionchanged:: 2.2.2
+      Support for the *chars* argument.
+
+
+.. method:: str.partition(sep)
+
+   Split the string at the first occurrence of *sep*, and return a 3-tuple
+   containing the part before the separator, the separator itself, and the part
+   after the separator.  If the separator is not found, return a 3-tuple containing
+   the string itself, followed by two empty strings.
+
+   .. versionadded:: 2.5
+
+
+.. method:: str.replace(old, new[, count])
+
+   Return a copy of the string with all occurrences of substring *old* replaced by
+   *new*.  If the optional argument *count* is given, only the first *count*
+   occurrences are replaced.
+
+
+.. method:: str.rfind(sub [,start [,end]])
+
+   Return the highest index in the string where substring *sub* is found, such that
+   *sub* is contained within s[start,end].  Optional arguments *start* and *end*
+   are interpreted as in slice notation.  Return ``-1`` on failure.
+
+
+.. method:: str.rindex(sub[, start[, end]])
+
+   Like :meth:`rfind` but raises :exc:`ValueError` when the substring *sub* is not
+   found.
+
+
+.. method:: str.rjust(width[, fillchar])
+
+   Return the string right justified in a string of length *width*. Padding is done
+   using the specified *fillchar* (default is a space). The original string is
+   returned if *width* is less than ``len(s)``.
+
+   .. versionchanged:: 2.4
+      Support for the *fillchar* argument.
+
+
+.. method:: str.rpartition(sep)
+
+   Split the string at the last occurrence of *sep*, and return a 3-tuple
+   containing the part before the separator, the separator itself, and the part
+   after the separator.  If the separator is not found, return a 3-tuple containing
+   two empty strings, followed by the string itself.
+
+   .. versionadded:: 2.5
+
+
+.. method:: str.rsplit([sep [,maxsplit]])
+
+   Return a list of the words in the string, using *sep* as the delimiter string.
+   If *maxsplit* is given, at most *maxsplit* splits are done, the *rightmost*
+   ones.  If *sep* is not specified or ``None``, any whitespace string is a
+   separator.  Except for splitting from the right, :meth:`rsplit` behaves like
+   :meth:`split` which is described in detail below.
+
+   .. versionadded:: 2.4
+
+
+.. method:: str.rstrip([chars])
+
+   Return a copy of the string with trailing characters removed.  The *chars*
+   argument is a string specifying the set of characters to be removed.  If omitted
+   or ``None``, the *chars* argument defaults to removing whitespace.  The *chars*
+   argument is not a suffix; rather, all combinations of its values are stripped::
+
+      >>> '   spacious   '.rstrip()
+      '   spacious'
+      >>> 'mississippi'.rstrip('ipz')
+      'mississ'
+
+   .. versionchanged:: 2.2.2
+      Support for the *chars* argument.
+
+
+.. method:: str.split([sep [,maxsplit]])
+
+   Return a list of the words in the string, using *sep* as the delimiter string.
+   If *maxsplit* is given, at most *maxsplit* splits are done. (thus, the list will
+   have at most ``maxsplit+1`` elements).  If *maxsplit* is not specified, then
+   there is no limit on the number of splits (all possible splits are made).
+   Consecutive delimiters are not grouped together and are deemed to delimit empty
+   strings (for example, ``'1,,2'.split(',')`` returns ``['1', '', '2']``).  The
+   *sep* argument may consist of multiple characters (for example, ``'1, 2,
+   3'.split(', ')`` returns ``['1', '2', '3']``).  Splitting an empty string with a
+   specified separator returns ``['']``.
+
+   If *sep* is not specified or is ``None``, a different splitting algorithm is
+   applied.  First, whitespace characters (spaces, tabs, newlines, returns, and
+   formfeeds) are stripped from both ends.  Then, words are separated by arbitrary
+   length strings of whitespace characters. Consecutive whitespace delimiters are
+   treated as a single delimiter (``'1  2  3'.split()`` returns ``['1', '2',
+   '3']``). Splitting an empty string or a string consisting of just whitespace
+   returns an empty list.
+
+
+.. method:: str.splitlines([keepends])
+
+   Return a list of the lines in the string, breaking at line boundaries.  Line
+   breaks are not included in the resulting list unless *keepends* is given and
+   true.
+
+
+.. method:: str.startswith(prefix[, start[, end]])
+
+   Return ``True`` if string starts with the *prefix*, otherwise return ``False``.
+   *prefix* can also be a tuple of prefixes to look for.  With optional *start*,
+   test string beginning at that position.  With optional *end*, stop comparing
+   string at that position.
+
+   .. versionchanged:: 2.5
+      Accept tuples as *prefix*.
+
+
+.. method:: str.strip([chars])
+
+   Return a copy of the string with the leading and trailing characters removed.
+   The *chars* argument is a string specifying the set of characters to be removed.
+   If omitted or ``None``, the *chars* argument defaults to removing whitespace.
+   The *chars* argument is not a prefix or suffix; rather, all combinations of its
+   values are stripped::
+
+      >>> '   spacious   '.strip()
+      'spacious'
+      >>> 'www.example.com'.strip('cmowz.')
+      'example'
+
+   .. versionchanged:: 2.2.2
+      Support for the *chars* argument.
+
+
+.. method:: str.swapcase()
+
+   Return a copy of the string with uppercase characters converted to lowercase and
+   vice versa.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.title()
+
+   Return a titlecased version of the string: words start with uppercase
+   characters, all remaining cased characters are lowercase.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.translate(table[, deletechars])
+
+   Return a copy of the string where all characters occurring in the optional
+   argument *deletechars* are removed, and the remaining characters have been
+   mapped through the given translation table, which must be a string of length
+   256.
+
+   You can use the :func:`maketrans` helper function in the :mod:`string` module to
+   create a translation table. For string objects, set the *table* argument to
+   ``None`` for translations that only delete characters::
+
+      >>> 'read this short text'.translate(None, 'aeiou')
+      'rd ths shrt txt'
+
+   .. versionadded:: 2.6
+      Support for a ``None`` *table* argument.
+
+   For Unicode objects, the :meth:`translate` method does not accept the optional
+   *deletechars* argument.  Instead, it returns a copy of the *s* where all
+   characters have been mapped through the given translation table which must be a
+   mapping of Unicode ordinals to Unicode ordinals, Unicode strings or ``None``.
+   Unmapped characters are left untouched. Characters mapped to ``None`` are
+   deleted.  Note, a more flexible approach is to create a custom character mapping
+   codec using the :mod:`codecs` module (see :mod:`encodings.cp1251` for an
+   example).
+
+
+.. method:: str.upper()
+
+   Return a copy of the string converted to uppercase.
+
+   For 8-bit strings, this method is locale-dependent.
+
+
+.. method:: str.zfill(width)
+
+   Return the numeric string left filled with zeros in a string of length *width*.
+   The original string is returned if *width* is less than ``len(s)``.
+
+   .. versionadded:: 2.2.2
+
+
+.. _string-formatting:
+
+String Formatting Operations
+----------------------------
+
+.. index::
+   single: formatting, string (%)
+   single: interpolation, string (%)
+   single: string; formatting
+   single: string; interpolation
+   single: printf-style formatting
+   single: sprintf-style formatting
+   single: % formatting
+   single: % interpolation
+
+String and Unicode objects have one unique built-in operation: the ``%``
+operator (modulo).  This is also known as the string *formatting* or
+*interpolation* operator.  Given ``format % values`` (where *format* is a string
+or Unicode object), ``%`` conversion specifications in *format* are replaced
+with zero or more elements of *values*.  The effect is similar to the using
+:cfunc:`sprintf` in the C language.  If *format* is a Unicode object, or if any
+of the objects being converted using the ``%s`` conversion are Unicode objects,
+the result will also be a Unicode object.
+
+If *format* requires a single argument, *values* may be a single non-tuple
+object. [#]_  Otherwise, *values* must be a tuple with exactly the number of
+items specified by the format string, or a single mapping object (for example, a
+dictionary).
+
+A conversion specifier contains two or more characters and has the following
+components, which must occur in this order:
+
+#. The ``'%'`` character, which marks the start of the specifier.
+
+#. Mapping key (optional), consisting of a parenthesised sequence of characters
+   (for example, ``(somename)``).
+
+#. Conversion flags (optional), which affect the result of some conversion
+   types.
+
+#. Minimum field width (optional).  If specified as an ``'*'`` (asterisk), the
+   actual width is read from the next element of the tuple in *values*, and the
+   object to convert comes after the minimum field width and optional precision.
+
+#. Precision (optional), given as a ``'.'`` (dot) followed by the precision.  If
+   specified as ``'*'`` (an asterisk), the actual width is read from the next
+   element of the tuple in *values*, and the value to convert comes after the
+   precision.
+
+#. Length modifier (optional).
+
+#. Conversion type.
+
+When the right argument is a dictionary (or other mapping type), then the
+formats in the string *must* include a parenthesised mapping key into that
+dictionary inserted immediately after the ``'%'`` character. The mapping key
+selects the value to be formatted from the mapping.  For example::
+
+   >>> print '%(language)s has %(#)03d quote types.' % \
+             {'language': "Python", "#": 2}
+   Python has 002 quote types.
+
+In this case no ``*`` specifiers may occur in a format (since they require a
+sequential parameter list).
+
+The conversion flag characters are:
+
++---------+---------------------------------------------------------------------+
+| Flag    | Meaning                                                             |
++=========+=====================================================================+
+| ``'#'`` | The value conversion will use the "alternate form" (where defined   |
+|         | below).                                                             |
++---------+---------------------------------------------------------------------+
+| ``'0'`` | The conversion will be zero padded for numeric values.              |
++---------+---------------------------------------------------------------------+
+| ``'-'`` | The converted value is left adjusted (overrides the ``'0'``         |
+|         | conversion if both are given).                                      |
++---------+---------------------------------------------------------------------+
+| ``' '`` | (a space) A blank should be left before a positive number (or empty |
+|         | string) produced by a signed conversion.                            |
++---------+---------------------------------------------------------------------+
+| ``'+'`` | A sign character (``'+'`` or ``'-'``) will precede the conversion   |
+|         | (overrides a "space" flag).                                         |
++---------+---------------------------------------------------------------------+
+
+A length modifier (``h``, ``l``, or ``L``) may be present, but is ignored as it
+is not necessary for Python.
+
+The conversion types are:
+
++------------+-----------------------------------------------------+-------+
+| Conversion | Meaning                                             | Notes |
++============+=====================================================+=======+
+| ``'d'``    | Signed integer decimal.                             |       |
++------------+-----------------------------------------------------+-------+
+| ``'i'``    | Signed integer decimal.                             |       |
++------------+-----------------------------------------------------+-------+
+| ``'o'``    | Unsigned octal.                                     | \(1)  |
++------------+-----------------------------------------------------+-------+
+| ``'u'``    | Unsigned decimal.                                   |       |
++------------+-----------------------------------------------------+-------+
+| ``'x'``    | Unsigned hexadecimal (lowercase).                   | \(2)  |
++------------+-----------------------------------------------------+-------+
+| ``'X'``    | Unsigned hexadecimal (uppercase).                   | \(2)  |
++------------+-----------------------------------------------------+-------+
+| ``'e'``    | Floating point exponential format (lowercase).      | \(3)  |
++------------+-----------------------------------------------------+-------+
+| ``'E'``    | Floating point exponential format (uppercase).      | \(3)  |
++------------+-----------------------------------------------------+-------+
+| ``'f'``    | Floating point decimal format.                      | \(3)  |
++------------+-----------------------------------------------------+-------+
+| ``'F'``    | Floating point decimal format.                      | \(3)  |
++------------+-----------------------------------------------------+-------+
+| ``'g'``    | Floating point format. Uses exponential format if   | \(4)  |
+|            | exponent is greater than -4 or less than precision, |       |
+|            | decimal format otherwise.                           |       |
++------------+-----------------------------------------------------+-------+
+| ``'G'``    | Floating point format. Uses exponential format if   | \(4)  |
+|            | exponent is greater than -4 or less than precision, |       |
+|            | decimal format otherwise.                           |       |
++------------+-----------------------------------------------------+-------+
+| ``'c'``    | Single character (accepts integer or single         |       |
+|            | character string).                                  |       |
++------------+-----------------------------------------------------+-------+
+| ``'r'``    | String (converts any python object using            | \(5)  |
+|            | :func:`repr`).                                      |       |
++------------+-----------------------------------------------------+-------+
+| ``'s'``    | String (converts any python object using            | \(6)  |
+|            | :func:`str`).                                       |       |
++------------+-----------------------------------------------------+-------+
+| ``'%'``    | No argument is converted, results in a ``'%'``      |       |
+|            | character in the result.                            |       |
++------------+-----------------------------------------------------+-------+
+
+Notes:
+
+(1)
+   The alternate form causes a leading zero (``'0'``) to be inserted between
+   left-hand padding and the formatting of the number if the leading character
+   of the result is not already a zero.
+
+(2)
+   The alternate form causes a leading ``'0x'`` or ``'0X'`` (depending on whether
+   the ``'x'`` or ``'X'`` format was used) to be inserted between left-hand padding
+   and the formatting of the number if the leading character of the result is not
+   already a zero.
+
+(3)
+   The alternate form causes the result to always contain a decimal point, even if
+   no digits follow it.
+
+   The precision determines the number of digits after the decimal point and
+   defaults to 6.
+
+(4)
+   The alternate form causes the result to always contain a decimal point, and
+   trailing zeroes are not removed as they would otherwise be.
+
+   The precision determines the number of significant digits before and after the
+   decimal point and defaults to 6.
+
+(5)
+   The ``%r`` conversion was added in Python 2.0.
+
+   The precision determines the maximal number of characters used.
+
+(6)
+   If the object or format provided is a :class:`unicode` string, the resulting
+   string will also be :class:`unicode`.
+
+   The precision determines the maximal number of characters used.
+
+Since Python strings have an explicit length, ``%s`` conversions do not assume
+that ``'\0'`` is the end of the string.
+
+.. % XXX Examples?
+
+For safety reasons, floating point precisions are clipped to 50; ``%f``
+conversions for numbers whose absolute value is over 1e25 are replaced by ``%g``
+conversions. [#]_  All other errors raise exceptions.
+
+.. index::
+   module: string
+   module: re
+
+Additional string operations are defined in standard modules :mod:`string` and
+:mod:`re`.
+
+
+.. _typesseq-range:
+
+XRange Type
+-----------
+
+.. index:: object: range
+
+The :class:`range` type is an immutable sequence which is commonly used for
+looping.  The advantage of the :class:`range` type is that an :class:`range`
+object will always take the same amount of memory, no matter the size of the
+range it represents.  There are no consistent performance advantages.
+
+XRange objects have very little behavior: they only support indexing, iteration,
+and the :func:`len` function.
+
+
+.. _typesseq-mutable:
+
+Mutable Sequence Types
+----------------------
+
+.. index::
+   triple: mutable; sequence; types
+   object: list
+
+List objects support additional operations that allow in-place modification of
+the object. Other mutable sequence types (when added to the language) should
+also support these operations. Strings and tuples are immutable sequence types:
+such objects cannot be modified once created. The following operations are
+defined on mutable sequence types (where *x* is an arbitrary object):
+
++------------------------------+--------------------------------+---------------------+
+| Operation                    | Result                         | Notes               |
++==============================+================================+=====================+
+| ``s[i] = x``                 | item *i* of *s* is replaced by |                     |
+|                              | *x*                            |                     |
++------------------------------+--------------------------------+---------------------+
+| ``s[i:j] = t``               | slice of *s* from *i* to *j*   |                     |
+|                              | is replaced by the contents of |                     |
+|                              | the iterable *t*               |                     |
++------------------------------+--------------------------------+---------------------+
+| ``del s[i:j]``               | same as ``s[i:j] = []``        |                     |
++------------------------------+--------------------------------+---------------------+
+| ``s[i:j:k] = t``             | the elements of ``s[i:j:k]``   | \(1)                |
+|                              | are replaced by those of *t*   |                     |
++------------------------------+--------------------------------+---------------------+
+| ``del s[i:j:k]``             | removes the elements of        |                     |
+|                              | ``s[i:j:k]`` from the list     |                     |
++------------------------------+--------------------------------+---------------------+
+| ``s.append(x)``              | same as ``s[len(s):len(s)] =   | \(2)                |
+|                              | [x]``                          |                     |
++------------------------------+--------------------------------+---------------------+
+| ``s.extend(x)``              | same as ``s[len(s):len(s)] =   | \(3)                |
+|                              | x``                            |                     |
++------------------------------+--------------------------------+---------------------+
+| ``s.count(x)``               | return number of *i*'s for     |                     |
+|                              | which ``s[i] == x``            |                     |
++------------------------------+--------------------------------+---------------------+
+| ``s.index(x[, i[, j]])``     | return smallest *k* such that  | \(4)                |
+|                              | ``s[k] == x`` and ``i <= k <   |                     |
+|                              | j``                            |                     |
++------------------------------+--------------------------------+---------------------+
+| ``s.insert(i, x)``           | same as ``s[i:i] = [x]``       | \(5)                |
++------------------------------+--------------------------------+---------------------+
+| ``s.pop([i])``               | same as ``x = s[i]; del s[i];  | \(6)                |
+|                              | return x``                     |                     |
++------------------------------+--------------------------------+---------------------+
+| ``s.remove(x)``              | same as ``del s[s.index(x)]``  | \(4)                |
++------------------------------+--------------------------------+---------------------+
+| ``s.reverse()``              | reverses the items of *s* in   | \(7)                |
+|                              | place                          |                     |
++------------------------------+--------------------------------+---------------------+
+| ``s.sort([cmp[, key[,        | sort the items of *s* in place | (7), (8), (9), (10) |
+| reverse]]])``                |                                |                     |
++------------------------------+--------------------------------+---------------------+
+
+.. index::
+   triple: operations on; sequence; types
+   triple: operations on; list; type
+   pair: subscript; assignment
+   pair: slice; assignment
+   pair: extended slice; assignment
+   statement: del
+   single: append() (list method)
+   single: extend() (list method)
+   single: count() (list method)
+   single: index() (list method)
+   single: insert() (list method)
+   single: pop() (list method)
+   single: remove() (list method)
+   single: reverse() (list method)
+   single: sort() (list method)
+
+Notes:
+
+(1)
+   *t* must have the same length as the slice it is  replacing.
+
+(2)
+   The C implementation of Python has historically accepted multiple parameters and
+   implicitly joined them into a tuple; this no longer works in Python 2.0.  Use of
+   this misfeature has been deprecated since Python 1.4.
+
+(3)
+   *x* can be any iterable object.
+
+(4)
+   Raises :exc:`ValueError` when *x* is not found in *s*. When a negative index is
+   passed as the second or third parameter to the :meth:`index` method, the list
+   length is added, as for slice indices.  If it is still negative, it is truncated
+   to zero, as for slice indices.
+
+   .. versionchanged:: 2.3
+      Previously, :meth:`index` didn't have arguments for specifying start and stop
+      positions.
+
+(5)
+   When a negative index is passed as the first parameter to the :meth:`insert`
+   method, the list length is added, as for slice indices.  If it is still
+   negative, it is truncated to zero, as for slice indices.
+
+   .. versionchanged:: 2.3
+      Previously, all negative indices were truncated to zero.
+
+(6)
+   The :meth:`pop` method is only supported by the list and array types.  The
+   optional argument *i* defaults to ``-1``, so that by default the last item is
+   removed and returned.
+
+(7)
+   The :meth:`sort` and :meth:`reverse` methods modify the list in place for
+   economy of space when sorting or reversing a large list.  To remind you that
+   they operate by side effect, they don't return the sorted or reversed list.
+
+(8)
+   The :meth:`sort` method takes optional arguments for controlling the
+   comparisons.
+
+   *cmp* specifies a custom comparison function of two arguments (list items) which
+   should return a negative, zero or positive number depending on whether the first
+   argument is considered smaller than, equal to, or larger than the second
+   argument: ``cmp=lambda x,y: cmp(x.lower(), y.lower())``
+
+   *key* specifies a function of one argument that is used to extract a comparison
+   key from each list element: ``key=str.lower``
+
+   *reverse* is a boolean value.  If set to ``True``, then the list elements are
+   sorted as if each comparison were reversed.
+
+   In general, the *key* and *reverse* conversion processes are much faster than
+   specifying an equivalent *cmp* function.  This is because *cmp* is called
+   multiple times for each list element while *key* and *reverse* touch each
+   element only once.
+
+   .. versionchanged:: 2.3
+      Support for ``None`` as an equivalent to omitting *cmp* was added.
+
+   .. versionchanged:: 2.4
+      Support for *key* and *reverse* was added.
+
+(9)
+   Starting with Python 2.3, the :meth:`sort` method is guaranteed to be stable.  A
+   sort is stable if it guarantees not to change the relative order of elements
+   that compare equal --- this is helpful for sorting in multiple passes (for
+   example, sort by department, then by salary grade).
+
+(10)
+   While a list is being sorted, the effect of attempting to mutate, or even
+   inspect, the list is undefined.  The C implementation of Python 2.3 and newer
+   makes the list appear empty for the duration, and raises :exc:`ValueError` if it
+   can detect that the list has been mutated during a sort.
+
+
+.. _types-set:
+
+Set Types --- :class:`set`, :class:`frozenset`
+==============================================
+
+.. index:: object: set
+
+A :dfn:`set` object is an unordered collection of distinct hashable objects.
+Common uses include membership testing, removing duplicates from a sequence, and
+computing mathematical operations such as intersection, union, difference, and
+symmetric difference.
+(For other containers see the built in :class:`dict`, :class:`list`,
+and :class:`tuple` classes, and the :mod:`collections` module.)
+
+
+.. versionadded:: 2.4
+
+Like other collections, sets support ``x in set``, ``len(set)``, and ``for x in
+set``.  Being an unordered collection, sets do not record element position or
+order of insertion.  Accordingly, sets do not support indexing, slicing, or
+other sequence-like behavior.
+
+There are currently two builtin set types, :class:`set` and :class:`frozenset`.
+The :class:`set` type is mutable --- the contents can be changed using methods
+like :meth:`add` and :meth:`remove`.  Since it is mutable, it has no hash value
+and cannot be used as either a dictionary key or as an element of another set.
+The :class:`frozenset` type is immutable and hashable --- its contents cannot be
+altered after it is created; it can therefore be used as a dictionary key or as
+an element of another set.
+
+The constructors for both classes work the same:
+
+.. class:: set([iterable])
+           frozenset([iterable])
+
+   Return a new set or frozenset object whose elements are taken from
+   *iterable*.  The elements of a set must be hashable.  To represent sets of
+   sets, the inner sets must be :class:`frozenset` objects.  If *iterable* is
+   not specified, a new empty set is returned.
+
+Instances of :class:`set` and :class:`frozenset` provide the following
+operations:
+
+.. describe:: len(s)
+
+   Return the cardinality of set *s*.
+
+.. describe:: x in s
+
+   Test *x* for membership in *s*.
+
+.. describe:: x not in s
+
+   Test *x* for non-membership in *s*.
+
+.. method:: set.issubset(other)
+            set <= other
+
+   Test whether every element in the set is in *other*.
+
+.. method:: set.issuperset(other)
+            set >= other
+
+   Test whether every element in *other* is in the set.
+
+.. method:: set.union(other)
+            set | other
+
+   Return a new set with elements from both sets.
+
+.. method:: set.intersection(other)
+            set & other
+
+   Return a new set with elements common to both sets.
+
+.. method:: set.difference(other)
+            set - other
+
+   Return a new set with elements in the set that are not in *other*.
+
+.. method:: set.symmetric_difference(other)
+            set ^ other
+
+   Return a new set with elements in either the set or *other* but not both.
+
+.. method:: set.copy()
+
+   Return a new set with a shallow copy of *s*.
+
+
+Note, the non-operator versions of :meth:`union`, :meth:`intersection`,
+:meth:`difference`, and :meth:`symmetric_difference`, :meth:`issubset`, and
+:meth:`issuperset` methods will accept any iterable as an argument.  In
+contrast, their operator based counterparts require their arguments to be sets.
+This precludes error-prone constructions like ``set('abc') & 'cbs'`` in favor of
+the more readable ``set('abc').intersection('cbs')``.
+
+Both :class:`set` and :class:`frozenset` support set to set comparisons. Two
+sets are equal if and only if every element of each set is contained in the
+other (each is a subset of the other). A set is less than another set if and
+only if the first set is a proper subset of the second set (is a subset, but is
+not equal). A set is greater than another set if and only if the first set is a
+proper superset of the second set (is a superset, but is not equal).
+
+Instances of :class:`set` are compared to instances of :class:`frozenset` based
+on their members.  For example, ``set('abc') == frozenset('abc')`` returns
+``True``.
+
+The subset and equality comparisons do not generalize to a complete ordering
+function.  For example, any two disjoint sets are not equal and are not subsets
+of each other, so *all* of the following return ``False``:  ``a<b``, ``a==b``,
+or ``a>b``. Accordingly, sets do not implement the :meth:`__cmp__` method.
+
+Since sets only define partial ordering (subset relationships), the output of
+the :meth:`list.sort` method is undefined for lists of sets.
+
+Set elements are like dictionary keys; they need to define both :meth:`__hash__`
+and :meth:`__eq__` methods.
+
+Binary operations that mix :class:`set` instances with :class:`frozenset` return
+the type of the first operand.  For example: ``frozenset('ab') | set('bc')``
+returns an instance of :class:`frozenset`.
+
+The following table lists operations available for :class:`set` that do not
+apply to immutable instances of :class:`frozenset`:
+
+.. method:: set.update(other)
+            set |= other
+
+   Update the set, adding elements from *other*.
+
+.. method:: set.intersection_update(other)
+            set &= other
+
+   Update the set, keeping only elements found in it and *other*.
+
+.. method:: set.difference_update(other)
+            set -= other
+
+   Update the set, removing elements found in *other*.
+
+.. method:: set.symmetric_difference_update(other)
+            set ^= other
+
+   Update the set, keeping only elements found in either set, but not in both.
+
+.. method:: set.add(el)
+
+   Add element *el* to the set.
+
+.. method:: set.remove(el)
+
+   Remove element *el* from the set.  Raises :exc:`KeyError` if *el* is not
+   contained in the set.
+
+.. method:: set.discard(el)
+
+   Remove element *el* from the set if it is present.
+
+.. method:: set.pop()
+
+   Remove and return an arbitrary element from the set.  Raises :exc:`KeyError`
+   if the set is empty.
+
+.. method:: set.clear()
+
+   Remove all elements from the set.
+
+
+Note, the non-operator versions of the :meth:`update`,
+:meth:`intersection_update`, :meth:`difference_update`, and
+:meth:`symmetric_difference_update` methods will accept any iterable as an
+argument.
+
+
+.. _typesmapping:
+
+Mapping Types --- :class:`dict`
+===============================
+
+.. index::
+   object: mapping
+   object: dictionary
+   triple: operations on; mapping; types
+   triple: operations on; dictionary; type
+   statement: del
+   builtin: len
+
+A :dfn:`mapping` object maps immutable values to arbitrary objects.  Mappings
+are mutable objects.  There is currently only one standard mapping type, the
+:dfn:`dictionary`.
+(For other containers see the built in :class:`list`,
+:class:`set`, and :class:`tuple` classes, and the :mod:`collections`
+module.)
+
+A dictionary's keys are *almost* arbitrary values.  Only
+values containing lists, dictionaries or other mutable types (that are compared
+by value rather than by object identity) may not be used as keys. Numeric types
+used for keys obey the normal rules for numeric comparison: if two numbers
+compare equal (such as ``1`` and ``1.0``) then they can be used interchangeably
+to index the same dictionary entry. (Note however, that since computers
+store floating-point numbers as approximations it is usually unwise to
+use them as dictionary keys.)
+
+Dictionaries can be created by placing a comma-separated list of ``key: value``
+pairs within braces, for example: ``{'jack': 4098, 'sjoerd': 4127}`` or ``{4098:
+'jack', 4127: 'sjoerd'}``, or by the :class:`dict` constructor.
+
+.. class:: dict([arg])
+
+   Return a new dictionary initialized from an optional positional argument or from
+   a set of keyword arguments. If no arguments are given, return a new empty
+   dictionary. If the positional argument *arg* is a mapping object, return a
+   dictionary mapping the same keys to the same values as does the mapping object.
+   Otherwise the positional argument must be a sequence, a container that supports
+   iteration, or an iterator object.  The elements of the argument must each also
+   be of one of those kinds, and each must in turn contain exactly two objects.
+   The first is used as a key in the new dictionary, and the second as the key's
+   value.  If a given key is seen more than once, the last value associated with it
+   is retained in the new dictionary.
+
+   If keyword arguments are given, the keywords themselves with their associated
+   values are added as items to the dictionary. If a key is specified both in the
+   positional argument and as a keyword argument, the value associated with the
+   keyword is retained in the dictionary. For example, these all return a
+   dictionary equal to ``{"one": 2, "two": 3}``:
+
+   * ``dict(one=2, two=3)``
+
+   * ``dict({'one': 2, 'two': 3})``
+
+   * ``dict(zip(('one', 'two'), (2, 3)))``
+
+   * ``dict([['two', 3], ['one', 2]])``
+
+   The first example only works for keys that are valid Python
+   identifiers; the others work with any valid keys.
+
+   .. versionadded:: 2.2
+
+   .. versionchanged:: 2.3
+      Support for building a dictionary from keyword arguments added.
+
+
+These are the operations that dictionaries support (and therefore, custom mapping
+types should support too):
+
+.. describe:: len(d)
+
+   Return the number of items in the dictionary *d*.
+
+.. describe:: d[key]
+
+   Return the item of *d* with key *key*.  Raises a :exc:`KeyError` if *key* is
+   not in the map.
+   
+   .. versionadded:: 2.5
+      If a subclass of dict defines a method :meth:`__missing__`, if the key
+      *key* is not present, the ``d[key]`` operation calls that method with the
+      key *key* as argument.  The ``d[key]`` operation then returns or raises
+      whatever is returned or raised by the ``__missing__(key)`` call if the key
+      is not present. No other operations or methods invoke
+      :meth:`__missing__`. If :meth:`__missing__` is not defined,
+      :exc:`KeyError` is raised.  :meth:`__missing__` must be a method; it
+      cannot be an instance variable. For an example, see
+      :class:`collections.defaultdict`.
+
+.. describe:: d[key] = value
+
+   Set ``d[key]`` to *value*.
+
+.. describe:: del d[key]
+
+   Remove ``d[key]`` from *d*.  Raises a :exc:`KeyError` if *key* is not in the
+   map.
+
+.. describe:: key in d
+
+   Return ``True`` if *d* has a key *key*, else ``False``.
+
+   .. versionadded:: 2.2
+
+.. describe:: key not in d
+
+   Equivalent to ``not key in d``.
+
+   .. versionadded:: 2.2
+
+.. method:: dict.clear()
+
+   Remove all items from the dictionary.
+
+.. method:: dict.copy()
+
+   Return a shallow copy of the dictionary.
+
+.. method:: dict.fromkeys(seq[, value])
+
+   Create a new dictionary with keys from *seq* and values set to *value*.
+
+   :func:`fromkeys` is a class method that returns a new dictionary. *value*
+   defaults to ``None``.
+
+   .. versionadded:: 2.3
+
+.. method:: dict.get(key[, default])
+
+   Return the value for *key* if *key* is in the dictionary, else *default*.  If
+   *default* is not given, it defaults to ``None``, so that this method never
+   raises a :exc:`KeyError`.
+
+.. method:: dict.has_key(key)
+
+   ``d.has_key(key)`` is equivalent to ``key in d``, but deprecated.
+
+.. method:: dict.items()
+
+   Return a copy of the dictionary's list of ``(key, value)`` pairs.
+
+   .. note::
+
+      Keys and values are listed in an arbitrary order which is non-random, varies
+      across Python implementations, and depends on the dictionary's history of
+      insertions and deletions. If :meth:`items`, :meth:`keys`, :meth:`values`,
+      :meth:`iteritems`, :meth:`iterkeys`, and :meth:`itervalues` are called with no
+      intervening modifications to the dictionary, the lists will directly correspond.
+      This allows the creation of ``(value, key)`` pairs using :func:`zip`: ``pairs =
+      zip(d.values(), d.keys())``.  The same relationship holds for the
+      :meth:`iterkeys` and :meth:`itervalues` methods: ``pairs = zip(d.itervalues(),
+      d.iterkeys())`` provides the same value for ``pairs``. Another way to create the
+      same list is ``pairs = [(v, k) for (k, v) in d.iteritems()]``.
+
+.. method:: dict.iteritems()
+
+   Return an iterator over the dictionary's ``(key, value)`` pairs.
+   See the note for :meth:`dict.items`.
+
+   .. versionadded:: 2.2
+
+.. method:: dict.iterkeys()
+
+   Return an iterator over the dictionary's keys.  See the note for
+   :meth:`dict.items`.
+
+   .. versionadded:: 2.2
+
+.. method:: dict.itervalues()
+
+   Return an iterator over the dictionary's values.  See the note for
+   :meth:`dict.items`.
+
+   .. versionadded:: 2.2
+
+.. method:: dict.keys()
+
+   Return a copy of the dictionary's list of keys.  See the note for
+   :meth:`dict.items`.
+
+.. method:: dict.pop(key[, default])
+
+   If *key* is in the dictionary, remove it and return its value, else return
+   *default*.  If *default* is not given and *key* is not in the dictionary, a
+   :exc:`KeyError` is raised.
+
+   .. versionadded:: 2.3
+
+.. method:: dict.popitem()
+
+   Remove and return an arbitrary ``(key, value)`` pair from the dictionary.
+
+   :func:`popitem` is useful to destructively iterate over a dictionary, as
+   often used in set algorithms.  If the dictionary is empty, calling
+   :func:`popitem` raises a :exc:`KeyError`.
+
+.. method:: dict.setdefault(key[, default])
+
+   If *key* is in the dictionary, return its value.  If not, insert *key* with a
+   value of *default* and return *default*.  *default* defaults to ``None``.
+
+.. method:: dict.update([other])
+
+   Update the dictionary with the key/value pairs from *other*, overwriting existing
+   keys.  Return ``None``.
+
+   :func:`update` accepts either another dictionary object or an iterable of
+   key/value pairs (as a tuple or other iterable of length two).  If keyword
+   arguments are specified, the dictionary is then is updated with those
+   key/value pairs: ``d.update(red=1, blue=2)``.
+
+   .. versionchanged:: 2.4
+      Allowed the argument to be an iterable of key/value pairs and allowed
+      keyword arguments.
+
+.. method:: dict.values()
+
+   Return a copy of the dictionary's list of values.  See the note for
+   :meth:`mapping.items`.
+
+
+.. _bltin-file-objects:
+
+File Objects
+============
+
+.. index::
+   object: file
+   builtin: file
+   module: os
+   module: socket
+
+File objects are implemented using C's ``stdio`` package and can be
+created with the built-in :func:`file` and (more usually) :func:`open`
+constructors described in the :ref:`built-in-funcs` section. [#]_ File
+objects are also returned by some other built-in functions and methods,
+such as :func:`os.popen` and :func:`os.fdopen` and the :meth:`makefile`
+method of socket objects.
+
+When a file operation fails for an I/O-related reason, the exception
+:exc:`IOError` is raised.  This includes situations where the operation is not
+defined for some reason, like :meth:`seek` on a tty device or writing a file
+opened for reading.
+
+Files have the following methods:
+
+
+.. method:: file.close()
+
+   Close the file.  A closed file cannot be read or written any more. Any operation
+   which requires that the file be open will raise a :exc:`ValueError` after the
+   file has been closed.  Calling :meth:`close` more than once is allowed.
+
+   As of Python 2.5, you can avoid having to call this method explicitly if you use
+   the :keyword:`with` statement.  For example, the following code will
+   automatically close ``f`` when the :keyword:`with` block is exited::
+
+      from __future__ import with_statement
+
+      with open("hello.txt") as f:
+          for line in f:
+              print line
+
+   In older versions of Python, you would have needed to do this to get the same
+   effect::
+
+      f = open("hello.txt")
+      try:
+          for line in f:
+              print line
+      finally:
+          f.close()
+
+   .. note::
+
+      Not all "file-like" types in Python support use as a context manager for the
+      :keyword:`with` statement.  If your code is intended to work with any file-like
+      object, you can use the function :func:`contextlib.closing` instead of using
+      the object directly.
+
+
+.. method:: file.flush()
+
+   Flush the internal buffer, like ``stdio``'s :cfunc:`fflush`.  This may be a
+   no-op on some file-like objects.
+
+
+.. method:: file.fileno()
+
+   .. index::
+      single: file descriptor
+      single: descriptor, file
+      module: fcntl
+
+   Return the integer "file descriptor" that is used by the underlying
+   implementation to request I/O operations from the operating system.  This can be
+   useful for other, lower level interfaces that use file descriptors, such as the
+   :mod:`fcntl` module or :func:`os.read` and friends.
+
+   .. note::
+
+      File-like objects which do not have a real file descriptor should *not* provide
+      this method!
+
+
+.. method:: file.isatty()
+
+   Return ``True`` if the file is connected to a tty(-like) device, else ``False``.
+
+   .. note::
+
+      If a file-like object is not associated with a real file, this method should
+      *not* be implemented.
+
+
+.. method:: file.__next__()
+
+   A file object is its own iterator, for example ``iter(f)`` returns *f* (unless
+   *f* is closed).  When a file is used as an iterator, typically in a
+   :keyword:`for` loop (for example, ``for line in f: print line``), the
+   :meth:`__next__` method is called repeatedly.  This method returns the next
+   input line, or raises :exc:`StopIteration` when EOF is hit when the file is open
+   for reading (behavior is undefined when the file is open for writing).  In order
+   to make a :keyword:`for` loop the most efficient way of looping over the lines
+   of a file (a very common operation), the :meth:`__next__` method uses a hidden
+   read-ahead buffer.  As a consequence of using a read-ahead buffer, combining
+   :meth:`__next__` with other file methods (like :meth:`readline`) does not work
+   right.  However, using :meth:`seek` to reposition the file to an absolute
+   position will flush the read-ahead buffer.
+
+   .. versionadded:: 2.3
+
+
+.. method:: file.read([size])
+
+   Read at most *size* bytes from the file (less if the read hits EOF before
+   obtaining *size* bytes).  If the *size* argument is negative or omitted, read
+   all data until EOF is reached.  The bytes are returned as a string object.  An
+   empty string is returned when EOF is encountered immediately.  (For certain
+   files, like ttys, it makes sense to continue reading after an EOF is hit.)  Note
+   that this method may call the underlying C function :cfunc:`fread` more than
+   once in an effort to acquire as close to *size* bytes as possible. Also note
+   that when in non-blocking mode, less data than what was requested may be
+   returned, even if no *size* parameter was given.
+
+
+.. method:: file.readline([size])
+
+   Read one entire line from the file.  A trailing newline character is kept in the
+   string (but may be absent when a file ends with an incomplete line). [#]_  If
+   the *size* argument is present and non-negative, it is a maximum byte count
+   (including the trailing newline) and an incomplete line may be returned. An
+   empty string is returned *only* when EOF is encountered immediately.
+
+   .. note::
+
+      Unlike ``stdio``'s :cfunc:`fgets`, the returned string contains null characters
+      (``'\0'``) if they occurred in the input.
+
+
+.. method:: file.readlines([sizehint])
+
+   Read until EOF using :meth:`readline` and return a list containing the lines
+   thus read.  If the optional *sizehint* argument is present, instead of
+   reading up to EOF, whole lines totalling approximately *sizehint* bytes
+   (possibly after rounding up to an internal buffer size) are read.  Objects
+   implementing a file-like interface may choose to ignore *sizehint* if it
+   cannot be implemented, or cannot be implemented efficiently.
+
+
+.. method:: file.seek(offset[, whence])
+
+   Set the file's current position, like ``stdio``'s :cfunc:`fseek`. The *whence*
+   argument is optional and defaults to  ``os.SEEK_SET`` or ``0`` (absolute file
+   positioning); other values are ``os.SEEK_CUR`` or ``1`` (seek relative to the
+   current position) and ``os.SEEK_END`` or ``2``  (seek relative to the file's
+   end).  There is no return value.  Note that if the file is opened for appending
+   (mode ``'a'`` or ``'a+'``), any :meth:`seek` operations will be undone at the
+   next write.  If the file is only opened for writing in append mode (mode
+   ``'a'``), this method is essentially a no-op, but it remains useful for files
+   opened in append mode with reading enabled (mode ``'a+'``).  If the file is
+   opened in text mode (without ``'b'``), only offsets returned by :meth:`tell` are
+   legal.  Use of other offsets causes undefined behavior.
+
+   Note that not all file objects are seekable.
+
+   .. versionchanged:: 2.6
+      Passing float values as offset has been deprecated
+
+
+.. method:: file.tell()
+
+   Return the file's current position, like ``stdio``'s :cfunc:`ftell`.
+
+   .. note::
+
+      On Windows, :meth:`tell` can return illegal values (after an :cfunc:`fgets`)
+      when reading files with Unix-style line-endings. Use binary mode (``'rb'``) to
+      circumvent this problem.
+
+
+.. method:: file.truncate([size])
+
+   Truncate the file's size.  If the optional *size* argument is present, the file
+   is truncated to (at most) that size.  The size defaults to the current position.
+   The current file position is not changed.  Note that if a specified size exceeds
+   the file's current size, the result is platform-dependent:  possibilities
+   include that the file may remain unchanged, increase to the specified size as if
+   zero-filled, or increase to the specified size with undefined new content.
+   Availability:  Windows, many Unix variants.
+
+
+.. method:: file.write(str)
+
+   Write a string to the file.  There is no return value.  Due to buffering, the
+   string may not actually show up in the file until the :meth:`flush` or
+   :meth:`close` method is called.
+
+
+.. method:: file.writelines(sequence)
+
+   Write a sequence of strings to the file.  The sequence can be any iterable
+   object producing strings, typically a list of strings. There is no return value.
+   (The name is intended to match :meth:`readlines`; :meth:`writelines` does not
+   add line separators.)
+
+Files support the iterator protocol.  Each iteration returns the same result as
+``file.readline()``, and iteration ends when the :meth:`readline` method returns
+an empty string.
+
+File objects also offer a number of other interesting attributes. These are not
+required for file-like objects, but should be implemented if they make sense for
+the particular object.
+
+
+.. attribute:: file.closed
+
+   bool indicating the current state of the file object.  This is a read-only
+   attribute; the :meth:`close` method changes the value. It may not be available
+   on all file-like objects.
+
+
+.. attribute:: file.encoding
+
+   The encoding that this file uses. When Unicode strings are written to a file,
+   they will be converted to byte strings using this encoding. In addition, when
+   the file is connected to a terminal, the attribute gives the encoding that the
+   terminal is likely to use (that  information might be incorrect if the user has
+   misconfigured the  terminal). The attribute is read-only and may not be present
+   on all file-like objects. It may also be ``None``, in which case the file uses
+   the system default encoding for converting Unicode strings.
+
+   .. versionadded:: 2.3
+
+
+.. attribute:: file.mode
+
+   The I/O mode for the file.  If the file was created using the :func:`open`
+   built-in function, this will be the value of the *mode* parameter.  This is a
+   read-only attribute and may not be present on all file-like objects.
+
+
+.. attribute:: file.name
+
+   If the file object was created using :func:`open`, the name of the file.
+   Otherwise, some string that indicates the source of the file object, of the
+   form ``<...>``.  This is a read-only attribute and may not be present on all
+   file-like objects.
+
+
+.. attribute:: file.newlines
+
+   If Python was built with the :option:`--with-universal-newlines` option to
+   :program:`configure` (the default) this read-only attribute exists, and for
+   files opened in universal newline read mode it keeps track of the types of
+   newlines encountered while reading the file. The values it can take are
+   ``'\r'``, ``'\n'``, ``'\r\n'``, ``None`` (unknown, no newlines read yet) or a
+   tuple containing all the newline types seen, to indicate that multiple newline
+   conventions were encountered. For files not opened in universal newline read
+   mode the value of this attribute will be ``None``.
+
+
+.. attribute:: file.softspace
+
+   Boolean that indicates whether a space character needs to be printed before
+   another value when using the :keyword:`print` statement. Classes that are trying
+   to simulate a file object should also have a writable :attr:`softspace`
+   attribute, which should be initialized to zero.  This will be automatic for most
+   classes implemented in Python (care may be needed for objects that override
+   attribute access); types implemented in C will have to provide a writable
+   :attr:`softspace` attribute.
+
+   .. note::
+
+      This attribute is not used to control the :keyword:`print` statement, but to
+      allow the implementation of :keyword:`print` to keep track of its internal
+      state.
+
+
+.. _typecontextmanager:
+
+Context Manager Types
+=====================
+
+.. versionadded:: 2.5
+
+.. index::
+   single: context manager
+   single: context management protocol
+   single: protocol; context management
+
+Python's :keyword:`with` statement supports the concept of a runtime context
+defined by a context manager.  This is implemented using two separate methods
+that allow user-defined classes to define a runtime context that is entered
+before the statement body is executed and exited when the statement ends.
+
+The :dfn:`context management protocol` consists of a pair of methods that need
+to be provided for a context manager object to define a runtime context:
+
+
+.. method:: contextmanager.__enter__()
+
+   Enter the runtime context and return either this object or another object
+   related to the runtime context. The value returned by this method is bound to
+   the identifier in the :keyword:`as` clause of :keyword:`with` statements using
+   this context manager.
+
+   An example of a context manager that returns itself is a file object. File
+   objects return themselves from __enter__() to allow :func:`open` to be used as
+   the context expression in a :keyword:`with` statement.
+
+   An example of a context manager that returns a related object is the one
+   returned by ``decimal.Context.get_manager()``. These managers set the active
+   decimal context to a copy of the original decimal context and then return the
+   copy. This allows changes to be made to the current decimal context in the body
+   of the :keyword:`with` statement without affecting code outside the
+   :keyword:`with` statement.
+
+
+.. method:: contextmanager.__exit__(exc_type, exc_val, exc_tb)
+
+   Exit the runtime context and return a Boolean flag indicating if any expection
+   that occurred should be suppressed. If an exception occurred while executing the
+   body of the :keyword:`with` statement, the arguments contain the exception type,
+   value and traceback information. Otherwise, all three arguments are ``None``.
+
+   Returning a true value from this method will cause the :keyword:`with` statement
+   to suppress the exception and continue execution with the statement immediately
+   following the :keyword:`with` statement. Otherwise the exception continues
+   propagating after this method has finished executing. Exceptions that occur
+   during execution of this method will replace any exception that occurred in the
+   body of the :keyword:`with` statement.
+
+   The exception passed in should never be reraised explicitly - instead, this
+   method should return a false value to indicate that the method completed
+   successfully and does not want to suppress the raised exception. This allows
+   context management code (such as ``contextlib.nested``) to easily detect whether
+   or not an :meth:`__exit__` method has actually failed.
+
+Python defines several context managers to support easy thread synchronisation,
+prompt closure of files or other objects, and simpler manipulation of the active
+decimal arithmetic context. The specific types are not treated specially beyond
+their implementation of the context management protocol. See the
+:mod:`contextlib` module for some examples.
+
+Python's generators and the ``contextlib.contextfactory`` decorator provide a
+convenient way to implement these protocols.  If a generator function is
+decorated with the ``contextlib.contextfactory`` decorator, it will return a
+context manager implementing the necessary :meth:`__enter__` and
+:meth:`__exit__` methods, rather than the iterator produced by an undecorated
+generator function.
+
+Note that there is no specific slot for any of these methods in the type
+structure for Python objects in the Python/C API. Extension types wanting to
+define these methods must provide them as a normal Python accessible method.
+Compared to the overhead of setting up the runtime context, the overhead of a
+single class dictionary lookup is negligible.
+
+
+.. _typesother:
+
+Other Built-in Types
+====================
+
+The interpreter supports several other kinds of objects. Most of these support
+only one or two operations.
+
+
+.. _typesmodules:
+
+Modules
+-------
+
+The only special operation on a module is attribute access: ``m.name``, where
+*m* is a module and *name* accesses a name defined in *m*'s symbol table.
+Module attributes can be assigned to.  (Note that the :keyword:`import`
+statement is not, strictly speaking, an operation on a module object; ``import
+foo`` does not require a module object named *foo* to exist, rather it requires
+an (external) *definition* for a module named *foo* somewhere.)
+
+A special member of every module is :attr:`__dict__`. This is the dictionary
+containing the module's symbol table. Modifying this dictionary will actually
+change the module's symbol table, but direct assignment to the :attr:`__dict__`
+attribute is not possible (you can write ``m.__dict__['a'] = 1``, which defines
+``m.a`` to be ``1``, but you can't write ``m.__dict__ = {}``).  Modifying
+:attr:`__dict__` directly is not recommended.
+
+Modules built into the interpreter are written like this: ``<module 'sys'
+(built-in)>``.  If loaded from a file, they are written as ``<module 'os' from
+'/usr/local/lib/pythonX.Y/os.pyc'>``.
+
+
+.. _typesobjects:
+
+Classes and Class Instances
+---------------------------
+
+See :ref:`objects` and :ref:`class` for these.
+
+
+.. _typesfunctions:
+
+Functions
+---------
+
+Function objects are created by function definitions.  The only operation on a
+function object is to call it: ``func(argument-list)``.
+
+There are really two flavors of function objects: built-in functions and
+user-defined functions.  Both support the same operation (to call the function),
+but the implementation is different, hence the different object types.
+
+See :ref:`function` for more information.
+
+
+.. _typesmethods:
+
+Methods
+-------
+
+.. index:: object: method
+
+Methods are functions that are called using the attribute notation. There are
+two flavors: built-in methods (such as :meth:`append` on lists) and class
+instance methods.  Built-in methods are described with the types that support
+them.
+
+The implementation adds two special read-only attributes to class instance
+methods: ``m.im_self`` is the object on which the method operates, and
+``m.im_func`` is the function implementing the method.  Calling ``m(arg-1,
+arg-2, ..., arg-n)`` is completely equivalent to calling ``m.im_func(m.im_self,
+arg-1, arg-2, ..., arg-n)``.
+
+Class instance methods are either *bound* or *unbound*, referring to whether the
+method was accessed through an instance or a class, respectively.  When a method
+is unbound, its ``im_self`` attribute will be ``None`` and if called, an
+explicit ``self`` object must be passed as the first argument.  In this case,
+``self`` must be an instance of the unbound method's class (or a subclass of
+that class), otherwise a :exc:`TypeError` is raised.
+
+Like function objects, methods objects support getting arbitrary attributes.
+However, since method attributes are actually stored on the underlying function
+object (``meth.im_func``), setting method attributes on either bound or unbound
+methods is disallowed.  Attempting to set a method attribute results in a
+:exc:`TypeError` being raised.  In order to set a method attribute, you need to
+explicitly set it on the underlying function object::
+
+   class C:
+       def method(self):
+           pass
+
+   c = C()
+   c.method.im_func.whoami = 'my name is c'
+
+See :ref:`types` for more information.
+
+
+.. _bltin-code-objects:
+
+Code Objects
+------------
+
+.. index:: object: code
+
+.. index::
+   builtin: compile
+   single: __code__ (function object attribute)
+
+Code objects are used by the implementation to represent "pseudo-compiled"
+executable Python code such as a function body. They differ from function
+objects because they don't contain a reference to their global execution
+environment.  Code objects are returned by the built-in :func:`compile` function
+and can be extracted from function objects through their :attr:`__code__`
+attribute. See also the :mod:`code` module.
+
+.. index::
+   builtin: exec
+   builtin: eval
+
+A code object can be executed or evaluated by passing it (instead of a source
+string) to the :func:`exec` or :func:`eval`  built-in functions.
+
+See :ref:`types` for more information.
+
+
+.. _bltin-type-objects:
+
+Type Objects
+------------
+
+.. index::
+   builtin: type
+   module: types
+
+Type objects represent the various object types.  An object's type is accessed
+by the built-in function :func:`type`.  There are no special operations on
+types.  The standard module :mod:`types` defines names for all standard built-in
+types.
+
+Types are written like this: ``<type 'int'>``.
+
+
+.. _bltin-null-object:
+
+The Null Object
+---------------
+
+This object is returned by functions that don't explicitly return a value.  It
+supports no special operations.  There is exactly one null object, named
+``None`` (a built-in name).
+
+It is written as ``None``.
+
+
+.. _bltin-ellipsis-object:
+
+The Ellipsis Object
+-------------------
+
+This object is mostly used by extended slice notation (see :ref:`slicings`).  It
+supports no special operations.  There is exactly one ellipsis object, named
+:const:`Ellipsis` (a built-in name).
+
+It is written as ``Ellipsis`` or ``...``.
+
+
+Boolean Values
+--------------
+
+Boolean values are the two constant objects ``False`` and ``True``.  They are
+used to represent truth values (although other values can also be considered
+false or true).  In numeric contexts (for example when used as the argument to
+an arithmetic operator), they behave like the integers 0 and 1, respectively.
+The built-in function :func:`bool` can be used to cast any value to a Boolean,
+if the value can be interpreted as a truth value (see section Truth Value
+Testing above).
+
+.. index::
+   single: False
+   single: True
+   pair: Boolean; values
+
+They are written as ``False`` and ``True``, respectively.
+
+
+.. _typesinternal:
+
+Internal Objects
+----------------
+
+See :ref:`types` for this information.  It describes stack frame objects,
+traceback objects, and slice objects.
+
+
+.. _specialattrs:
+
+Special Attributes
+==================
+
+The implementation adds a few special read-only attributes to several object
+types, where they are relevant.  Some of these are not reported by the
+:func:`dir` built-in function.
+
+
+.. attribute:: object.__dict__
+
+   A dictionary or other mapping object used to store an object's (writable)
+   attributes.
+
+
+.. attribute:: instance.__class__
+
+   The class to which a class instance belongs.
+
+
+.. attribute:: class.__bases__
+
+   The tuple of base classes of a class object.  If there are no base classes, this
+   will be an empty tuple.
+
+
+.. attribute:: class.__name__
+
+   The name of the class or type.
+
+.. rubric:: Footnotes
+
+.. [#] Additional information on these special methods may be found in the Python
+   Reference Manual (:ref:`customization`).
+
+.. [#] As a consequence, the list ``[1, 2]`` is considered equal to ``[1.0, 2.0]``, and
+   similarly for tuples.
+
+.. [#] They must have since the parser can't tell the type of the operands.
+
+.. [#] To format only a tuple you should therefore provide a singleton tuple whose only
+   element is the tuple to be formatted.
+
+.. [#] These numbers are fairly arbitrary.  They are intended to avoid printing endless
+   strings of meaningless digits without hampering correct use and without having
+   to know the exact precision of floating point values on a particular machine.
+
+.. [#] :func:`file` is new in Python 2.2.  The older built-in :func:`open` is an alias
+   for :func:`file`.
+
+.. [#] The advantage of leaving the newline on is that returning an empty string is
+   then an unambiguous EOF indication.  It is also possible (in cases where it
+   might matter, for example, if you want to make an exact copy of a file while
+   scanning its lines) to tell whether the last line of a file ended in a newline
+   or not (yes this happens!).
diff --git a/Doc/library/string.rst b/Doc/library/string.rst
new file mode 100644
index 0000000..aa2494b
--- /dev/null
+++ b/Doc/library/string.rst
@@ -0,0 +1,468 @@
+
+:mod:`string` --- Common string operations
+==========================================
+
+.. module:: string
+   :synopsis: Common string operations.
+
+
+.. index:: module: re
+
+The :mod:`string` module contains a number of useful constants and
+classes, as well as some deprecated legacy functions that are also
+available as methods on strings. In addition, Python's built-in string
+classes support the sequence type methods described in the
+:ref:`typesseq` section, and also the string-specific methods described
+in the :ref:`string-methods` section. To output formatted strings use
+template strings or the ``%`` operator described in the
+:ref:`string-formatting` section. Also, see the :mod:`re` module for
+string functions based on regular expressions.
+
+
+String constants
+----------------
+
+The constants defined in this module are:
+
+
+.. data:: ascii_letters
+
+   The concatenation of the :const:`ascii_lowercase` and :const:`ascii_uppercase`
+   constants described below.  This value is not locale-dependent.
+
+
+.. data:: ascii_lowercase
+
+   The lowercase letters ``'abcdefghijklmnopqrstuvwxyz'``.  This value is not
+   locale-dependent and will not change.
+
+
+.. data:: ascii_uppercase
+
+   The uppercase letters ``'ABCDEFGHIJKLMNOPQRSTUVWXYZ'``.  This value is not
+   locale-dependent and will not change.
+
+
+.. data:: digits
+
+   The string ``'0123456789'``.
+
+
+.. data:: hexdigits
+
+   The string ``'0123456789abcdefABCDEF'``.
+
+
+.. data:: octdigits
+
+   The string ``'01234567'``.
+
+
+.. data:: punctuation
+
+   String of ASCII characters which are considered punctuation characters
+   in the ``C`` locale.
+
+
+.. data:: printable
+
+   String of ASCII characters which are considered printable.  This is a
+   combination of :const:`digits`, :const:`ascii_letters`, :const:`punctuation`,
+   and :const:`whitespace`.
+
+
+.. data:: whitespace
+
+   A string containing all characters that are considered whitespace.
+   This includes the characters space, tab, linefeed, return, formfeed, and
+   vertical tab.
+
+
+Template strings
+----------------
+
+Templates provide simpler string substitutions as described in :pep:`292`.
+Instead of the normal ``%``\ -based substitutions, Templates support ``$``\
+-based substitutions, using the following rules:
+
+* ``$$`` is an escape; it is replaced with a single ``$``.
+
+* ``$identifier`` names a substitution placeholder matching a mapping key of
+  ``"identifier"``.  By default, ``"identifier"`` must spell a Python
+  identifier.  The first non-identifier character after the ``$`` character
+  terminates this placeholder specification.
+
+* ``${identifier}`` is equivalent to ``$identifier``.  It is required when valid
+  identifier characters follow the placeholder but are not part of the
+  placeholder, such as ``"${noun}ification"``.
+
+Any other appearance of ``$`` in the string will result in a :exc:`ValueError`
+being raised.
+
+.. versionadded:: 2.4
+
+The :mod:`string` module provides a :class:`Template` class that implements
+these rules.  The methods of :class:`Template` are:
+
+
+.. class:: Template(template)
+
+   The constructor takes a single argument which is the template string.
+
+
+.. method:: Template.substitute(mapping[, **kws])
+
+   Performs the template substitution, returning a new string.  *mapping* is any
+   dictionary-like object with keys that match the placeholders in the template.
+   Alternatively, you can provide keyword arguments, where the keywords are the
+   placeholders.  When both *mapping* and *kws* are given and there are duplicates,
+   the placeholders from *kws* take precedence.
+
+
+.. method:: Template.safe_substitute(mapping[, **kws])
+
+   Like :meth:`substitute`, except that if placeholders are missing from *mapping*
+   and *kws*, instead of raising a :exc:`KeyError` exception, the original
+   placeholder will appear in the resulting string intact.  Also, unlike with
+   :meth:`substitute`, any other appearances of the ``$`` will simply return ``$``
+   instead of raising :exc:`ValueError`.
+
+   While other exceptions may still occur, this method is called "safe" because
+   substitutions always tries to return a usable string instead of raising an
+   exception.  In another sense, :meth:`safe_substitute` may be anything other than
+   safe, since it will silently ignore malformed templates containing dangling
+   delimiters, unmatched braces, or placeholders that are not valid Python
+   identifiers.
+
+:class:`Template` instances also provide one public data attribute:
+
+
+.. attribute:: string.template
+
+   This is the object passed to the constructor's *template* argument.  In general,
+   you shouldn't change it, but read-only access is not enforced.
+
+Here is an example of how to use a Template::
+
+   >>> from string import Template
+   >>> s = Template('$who likes $what')
+   >>> s.substitute(who='tim', what='kung pao')
+   'tim likes kung pao'
+   >>> d = dict(who='tim')
+   >>> Template('Give $who $100').substitute(d)
+   Traceback (most recent call last):
+   [...]
+   ValueError: Invalid placeholder in string: line 1, col 10
+   >>> Template('$who likes $what').substitute(d)
+   Traceback (most recent call last):
+   [...]
+   KeyError: 'what'
+   >>> Template('$who likes $what').safe_substitute(d)
+   'tim likes $what'
+
+Advanced usage: you can derive subclasses of :class:`Template` to customize the
+placeholder syntax, delimiter character, or the entire regular expression used
+to parse template strings.  To do this, you can override these class attributes:
+
+* *delimiter* -- This is the literal string describing a placeholder introducing
+  delimiter.  The default value ``$``.  Note that this should *not* be a regular
+  expression, as the implementation will call :meth:`re.escape` on this string as
+  needed.
+
+* *idpattern* -- This is the regular expression describing the pattern for
+  non-braced placeholders (the braces will be added automatically as
+  appropriate).  The default value is the regular expression
+  ``[_a-z][_a-z0-9]*``.
+
+Alternatively, you can provide the entire regular expression pattern by
+overriding the class attribute *pattern*.  If you do this, the value must be a
+regular expression object with four named capturing groups.  The capturing
+groups correspond to the rules given above, along with the invalid placeholder
+rule:
+
+* *escaped* -- This group matches the escape sequence, e.g. ``$$``, in the
+  default pattern.
+
+* *named* -- This group matches the unbraced placeholder name; it should not
+  include the delimiter in capturing group.
+
+* *braced* -- This group matches the brace enclosed placeholder name; it should
+  not include either the delimiter or braces in the capturing group.
+
+* *invalid* -- This group matches any other delimiter pattern (usually a single
+  delimiter), and it should appear last in the regular expression.
+
+
+String functions
+----------------
+
+The following functions are available to operate on string and Unicode objects.
+They are not available as string methods.
+
+
+.. function:: capwords(s)
+
+   Split the argument into words using :func:`split`, capitalize each word using
+   :func:`capitalize`, and join the capitalized words using :func:`join`.  Note
+   that this replaces runs of whitespace characters by a single space, and removes
+   leading and trailing whitespace.
+
+
+.. function:: maketrans(from, to)
+
+   Return a translation table suitable for passing to :func:`translate`, that will
+   map each character in *from* into the character at the same position in *to*;
+   *from* and *to* must have the same length.
+
+   .. warning::
+
+      Don't use strings derived from :const:`lowercase` and :const:`uppercase` as
+      arguments; in some locales, these don't have the same length.  For case
+      conversions, always use :func:`lower` and :func:`upper`.
+
+
+Deprecated string functions
+---------------------------
+
+The following list of functions are also defined as methods of string and
+Unicode objects; see section :ref:`string-methods` for more information on
+those.  You should consider these functions as deprecated, although they will
+not be removed until Python 3.0.  The functions defined in this module are:
+
+
+.. function:: atof(s)
+
+   .. deprecated:: 2.0
+      Use the :func:`float` built-in function.
+
+   .. index:: builtin: float
+
+   Convert a string to a floating point number.  The string must have the standard
+   syntax for a floating point literal in Python, optionally preceded by a sign
+   (``+`` or ``-``).  Note that this behaves identical to the built-in function
+   :func:`float` when passed a string.
+
+   .. note::
+
+      .. index::
+         single: NaN
+         single: Infinity
+
+      When passing in a string, values for NaN and Infinity may be returned, depending
+      on the underlying C library.  The specific set of strings accepted which cause
+      these values to be returned depends entirely on the C library and is known to
+      vary.
+
+
+.. function:: atoi(s[, base])
+
+   .. deprecated:: 2.0
+      Use the :func:`int` built-in function.
+
+   .. index:: builtin: eval
+
+   Convert string *s* to an integer in the given *base*.  The string must consist
+   of one or more digits, optionally preceded by a sign (``+`` or ``-``).  The
+   *base* defaults to 10.  If it is 0, a default base is chosen depending on the
+   leading characters of the string (after stripping the sign): ``0x`` or ``0X``
+   means 16, ``0`` means 8, anything else means 10.  If *base* is 16, a leading
+   ``0x`` or ``0X`` is always accepted, though not required.  This behaves
+   identically to the built-in function :func:`int` when passed a string.  (Also
+   note: for a more flexible interpretation of numeric literals, use the built-in
+   function :func:`eval`.)
+
+
+.. function:: atol(s[, base])
+
+   .. deprecated:: 2.0
+      Use the :func:`long` built-in function.
+
+   .. index:: builtin: long
+
+   Convert string *s* to a long integer in the given *base*. The string must
+   consist of one or more digits, optionally preceded by a sign (``+`` or ``-``).
+   The *base* argument has the same meaning as for :func:`atoi`.  A trailing ``l``
+   or ``L`` is not allowed, except if the base is 0.  Note that when invoked
+   without *base* or with *base* set to 10, this behaves identical to the built-in
+   function :func:`long` when passed a string.
+
+
+.. function:: capitalize(word)
+
+   Return a copy of *word* with only its first character capitalized.
+
+
+.. function:: expandtabs(s[, tabsize])
+
+   Expand tabs in a string replacing them by one or more spaces, depending on the
+   current column and the given tab size.  The column number is reset to zero after
+   each newline occurring in the string. This doesn't understand other non-printing
+   characters or escape sequences.  The tab size defaults to 8.
+
+
+.. function:: find(s, sub[, start[,end]])
+
+   Return the lowest index in *s* where the substring *sub* is found such that
+   *sub* is wholly contained in ``s[start:end]``.  Return ``-1`` on failure.
+   Defaults for *start* and *end* and interpretation of negative values is the same
+   as for slices.
+
+
+.. function:: rfind(s, sub[, start[, end]])
+
+   Like :func:`find` but find the highest index.
+
+
+.. function:: index(s, sub[, start[, end]])
+
+   Like :func:`find` but raise :exc:`ValueError` when the substring is not found.
+
+
+.. function:: rindex(s, sub[, start[, end]])
+
+   Like :func:`rfind` but raise :exc:`ValueError` when the substring is not found.
+
+
+.. function:: count(s, sub[, start[, end]])
+
+   Return the number of (non-overlapping) occurrences of substring *sub* in string
+   ``s[start:end]``. Defaults for *start* and *end* and interpretation of negative
+   values are the same as for slices.
+
+
+.. function:: lower(s)
+
+   Return a copy of *s*, but with upper case letters converted to lower case.
+
+
+.. function:: split(s[, sep[, maxsplit]])
+
+   Return a list of the words of the string *s*.  If the optional second argument
+   *sep* is absent or ``None``, the words are separated by arbitrary strings of
+   whitespace characters (space, tab,  newline, return, formfeed).  If the second
+   argument *sep* is present and not ``None``, it specifies a string to be used as
+   the  word separator.  The returned list will then have one more item than the
+   number of non-overlapping occurrences of the separator in the string.  The
+   optional third argument *maxsplit* defaults to 0.  If it is nonzero, at most
+   *maxsplit* number of splits occur, and the remainder of the string is returned
+   as the final element of the list (thus, the list will have at most
+   ``maxsplit+1`` elements).
+
+   The behavior of split on an empty string depends on the value of *sep*. If *sep*
+   is not specified, or specified as ``None``, the result will be an empty list.
+   If *sep* is specified as any string, the result will be a list containing one
+   element which is an empty string.
+
+
+.. function:: rsplit(s[, sep[, maxsplit]])
+
+   Return a list of the words of the string *s*, scanning *s* from the end.  To all
+   intents and purposes, the resulting list of words is the same as returned by
+   :func:`split`, except when the optional third argument *maxsplit* is explicitly
+   specified and nonzero.  When *maxsplit* is nonzero, at most *maxsplit* number of
+   splits -- the *rightmost* ones -- occur, and the remainder of the string is
+   returned as the first element of the list (thus, the list will have at most
+   ``maxsplit+1`` elements).
+
+   .. versionadded:: 2.4
+
+
+.. function:: splitfields(s[, sep[, maxsplit]])
+
+   This function behaves identically to :func:`split`.  (In the past, :func:`split`
+   was only used with one argument, while :func:`splitfields` was only used with
+   two arguments.)
+
+
+.. function:: join(words[, sep])
+
+   Concatenate a list or tuple of words with intervening occurrences of  *sep*.
+   The default value for *sep* is a single space character.  It is always true that
+   ``string.join(string.split(s, sep), sep)`` equals *s*.
+
+
+.. function:: joinfields(words[, sep])
+
+   This function behaves identically to :func:`join`.  (In the past,  :func:`join`
+   was only used with one argument, while :func:`joinfields` was only used with two
+   arguments.) Note that there is no :meth:`joinfields` method on string objects;
+   use the :meth:`join` method instead.
+
+
+.. function:: lstrip(s[, chars])
+
+   Return a copy of the string with leading characters removed.  If *chars* is
+   omitted or ``None``, whitespace characters are removed.  If given and not
+   ``None``, *chars* must be a string; the characters in the string will be
+   stripped from the beginning of the string this method is called on.
+
+   .. versionchanged:: 2.2.3
+      The *chars* parameter was added.  The *chars* parameter cannot be passed in
+      earlier 2.2 versions.
+
+
+.. function:: rstrip(s[, chars])
+
+   Return a copy of the string with trailing characters removed.  If *chars* is
+   omitted or ``None``, whitespace characters are removed.  If given and not
+   ``None``, *chars* must be a string; the characters in the string will be
+   stripped from the end of the string this method is called on.
+
+   .. versionchanged:: 2.2.3
+      The *chars* parameter was added.  The *chars* parameter cannot be passed in
+      earlier 2.2 versions.
+
+
+.. function:: strip(s[, chars])
+
+   Return a copy of the string with leading and trailing characters removed.  If
+   *chars* is omitted or ``None``, whitespace characters are removed.  If given and
+   not ``None``, *chars* must be a string; the characters in the string will be
+   stripped from the both ends of the string this method is called on.
+
+   .. versionchanged:: 2.2.3
+      The *chars* parameter was added.  The *chars* parameter cannot be passed in
+      earlier 2.2 versions.
+
+
+.. function:: swapcase(s)
+
+   Return a copy of *s*, but with lower case letters converted to upper case and
+   vice versa.
+
+
+.. function:: translate(s, table[, deletechars])
+
+   Delete all characters from *s* that are in *deletechars* (if  present), and then
+   translate the characters using *table*, which  must be a 256-character string
+   giving the translation for each character value, indexed by its ordinal.  If
+   *table* is ``None``, then only the character deletion step is performed.
+
+
+.. function:: upper(s)
+
+   Return a copy of *s*, but with lower case letters converted to upper case.
+
+
+.. function:: ljust(s, width)
+              rjust(s, width)
+              center(s, width)
+
+   These functions respectively left-justify, right-justify and center a string in
+   a field of given width.  They return a string that is at least *width*
+   characters wide, created by padding the string *s* with spaces until the given
+   width on the right, left or both sides.  The string is never truncated.
+
+
+.. function:: zfill(s, width)
+
+   Pad a numeric string on the left with zero digits until the given width is
+   reached.  Strings starting with a sign are handled correctly.
+
+
+.. function:: replace(str, old, new[, maxreplace])
+
+   Return a copy of string *str* with all occurrences of substring *old* replaced
+   by *new*.  If the optional argument *maxreplace* is given, the first
+   *maxreplace* occurrences are replaced.
+
diff --git a/Doc/library/stringio.rst b/Doc/library/stringio.rst
new file mode 100644
index 0000000..9e2f0da
--- /dev/null
+++ b/Doc/library/stringio.rst
@@ -0,0 +1,122 @@
+
+:mod:`StringIO` --- Read and write strings as files
+===================================================
+
+.. module:: StringIO
+   :synopsis: Read and write strings as if they were files.
+
+
+This module implements a file-like class, :class:`StringIO`, that reads and
+writes a string buffer (also known as *memory files*).  See the description of
+file objects for operations (section :ref:`bltin-file-objects`).
+
+
+.. class:: StringIO([buffer])
+
+   When a :class:`StringIO` object is created, it can be initialized to an existing
+   string by passing the string to the constructor. If no string is given, the
+   :class:`StringIO` will start empty. In both cases, the initial file position
+   starts at zero.
+
+   The :class:`StringIO` object can accept either Unicode or 8-bit strings, but
+   mixing the two may take some care.  If both are used, 8-bit strings that cannot
+   be interpreted as 7-bit ASCII (that use the 8th bit) will cause a
+   :exc:`UnicodeError` to be raised when :meth:`getvalue` is called.
+
+The following methods of :class:`StringIO` objects require special mention:
+
+
+.. method:: StringIO.getvalue()
+
+   Retrieve the entire contents of the "file" at any time before the
+   :class:`StringIO` object's :meth:`close` method is called.  See the note above
+   for information about mixing Unicode and 8-bit strings; such mixing can cause
+   this method to raise :exc:`UnicodeError`.
+
+
+.. method:: StringIO.close()
+
+   Free the memory buffer.
+
+Example usage::
+
+   import StringIO
+
+   output = StringIO.StringIO()
+   output.write('First line.\n')
+   print >>output, 'Second line.'
+
+   # Retrieve file contents -- this will be
+   # 'First line.\nSecond line.\n'
+   contents = output.getvalue()
+
+   # Close object and discard memory buffer -- 
+   # .getvalue() will now raise an exception.
+   output.close()
+
+
+:mod:`cStringIO` --- Faster version of :mod:`StringIO`
+======================================================
+
+.. module:: cStringIO
+   :synopsis: Faster version of StringIO, but not subclassable.
+.. moduleauthor:: Jim Fulton <jim@zope.com>
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+The module :mod:`cStringIO` provides an interface similar to that of the
+:mod:`StringIO` module.  Heavy use of :class:`StringIO.StringIO` objects can be
+made more efficient by using the function :func:`StringIO` from this module
+instead.
+
+Since this module provides a factory function which returns objects of built-in
+types, there's no way to build your own version using subclassing.  Use the
+original :mod:`StringIO` module in that case.
+
+Unlike the memory files implemented by the :mod:`StringIO` module, those
+provided by this module are not able to accept Unicode strings that cannot be
+encoded as plain ASCII strings.
+
+Calling :func:`StringIO` with a Unicode string parameter populates
+the object with the buffer representation of the Unicode string, instead of
+encoding the string. 
+
+Another difference from the :mod:`StringIO` module is that calling
+:func:`StringIO` with a string parameter creates a read-only object. Unlike an
+object created without a string parameter, it does not have write methods.
+These objects are not generally visible.  They turn up in tracebacks as
+:class:`StringI` and :class:`StringO`.
+
+The following data objects are provided as well:
+
+
+.. data:: InputType
+
+   The type object of the objects created by calling :func:`StringIO` with a string
+   parameter.
+
+
+.. data:: OutputType
+
+   The type object of the objects returned by calling :func:`StringIO` with no
+   parameters.
+
+There is a C API to the module as well; refer to the module source for  more
+information.
+
+Example usage::
+
+   import cStringIO
+
+   output = cStringIO.StringIO()
+   output.write('First line.\n')
+   print >>output, 'Second line.'
+
+   # Retrieve file contents -- this will be
+   # 'First line.\nSecond line.\n'
+   contents = output.getvalue()
+
+   # Close object and discard memory buffer -- 
+   # .getvalue() will now raise an exception.
+   output.close()
+
diff --git a/Doc/library/stringprep.rst b/Doc/library/stringprep.rst
new file mode 100644
index 0000000..b0944e4
--- /dev/null
+++ b/Doc/library/stringprep.rst
@@ -0,0 +1,142 @@
+
+:mod:`stringprep` --- Internet String Preparation
+=================================================
+
+.. module:: stringprep
+   :synopsis: String preparation, as per RFC 3453
+.. moduleauthor:: Martin v. Löwis <martin@v.loewis.de>
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+
+
+.. versionadded:: 2.3
+
+When identifying things (such as host names) in the internet, it is often
+necessary to compare such identifications for "equality". Exactly how this
+comparison is executed may depend on the application domain, e.g. whether it
+should be case-insensitive or not. It may be also necessary to restrict the
+possible identifications, to allow only identifications consisting of
+"printable" characters.
+
+:rfc:`3454` defines a procedure for "preparing" Unicode strings in internet
+protocols. Before passing strings onto the wire, they are processed with the
+preparation procedure, after which they have a certain normalized form. The RFC
+defines a set of tables, which can be combined into profiles. Each profile must
+define which tables it uses, and what other optional parts of the ``stringprep``
+procedure are part of the profile. One example of a ``stringprep`` profile is
+``nameprep``, which is used for internationalized domain names.
+
+The module :mod:`stringprep` only exposes the tables from RFC 3454. As these
+tables would be very large to represent them as dictionaries or lists, the
+module uses the Unicode character database internally. The module source code
+itself was generated using the ``mkstringprep.py`` utility.
+
+As a result, these tables are exposed as functions, not as data structures.
+There are two kinds of tables in the RFC: sets and mappings. For a set,
+:mod:`stringprep` provides the "characteristic function", i.e. a function that
+returns true if the parameter is part of the set. For mappings, it provides the
+mapping function: given the key, it returns the associated value. Below is a
+list of all functions available in the module.
+
+
+.. function:: in_table_a1(code)
+
+   Determine whether *code* is in tableA.1 (Unassigned code points in Unicode 3.2).
+
+
+.. function:: in_table_b1(code)
+
+   Determine whether *code* is in tableB.1 (Commonly mapped to nothing).
+
+
+.. function:: map_table_b2(code)
+
+   Return the mapped value for *code* according to tableB.2 (Mapping for
+   case-folding used with NFKC).
+
+
+.. function:: map_table_b3(code)
+
+   Return the mapped value for *code* according to tableB.3 (Mapping for
+   case-folding used with no normalization).
+
+
+.. function:: in_table_c11(code)
+
+   Determine whether *code* is in tableC.1.1  (ASCII space characters).
+
+
+.. function:: in_table_c12(code)
+
+   Determine whether *code* is in tableC.1.2  (Non-ASCII space characters).
+
+
+.. function:: in_table_c11_c12(code)
+
+   Determine whether *code* is in tableC.1  (Space characters, union of C.1.1 and
+   C.1.2).
+
+
+.. function:: in_table_c21(code)
+
+   Determine whether *code* is in tableC.2.1  (ASCII control characters).
+
+
+.. function:: in_table_c22(code)
+
+   Determine whether *code* is in tableC.2.2  (Non-ASCII control characters).
+
+
+.. function:: in_table_c21_c22(code)
+
+   Determine whether *code* is in tableC.2  (Control characters, union of C.2.1 and
+   C.2.2).
+
+
+.. function:: in_table_c3(code)
+
+   Determine whether *code* is in tableC.3  (Private use).
+
+
+.. function:: in_table_c4(code)
+
+   Determine whether *code* is in tableC.4  (Non-character code points).
+
+
+.. function:: in_table_c5(code)
+
+   Determine whether *code* is in tableC.5  (Surrogate codes).
+
+
+.. function:: in_table_c6(code)
+
+   Determine whether *code* is in tableC.6  (Inappropriate for plain text).
+
+
+.. function:: in_table_c7(code)
+
+   Determine whether *code* is in tableC.7  (Inappropriate for canonical
+   representation).
+
+
+.. function:: in_table_c8(code)
+
+   Determine whether *code* is in tableC.8  (Change display properties or are
+   deprecated).
+
+
+.. function:: in_table_c9(code)
+
+   Determine whether *code* is in tableC.9  (Tagging characters).
+
+
+.. function:: in_table_d1(code)
+
+   Determine whether *code* is in tableD.1  (Characters with bidirectional property
+   "R" or "AL").
+
+
+.. function:: in_table_d2(code)
+
+   Determine whether *code* is in tableD.2  (Characters with bidirectional property
+   "L").
+
diff --git a/Doc/library/strings.rst b/Doc/library/strings.rst
new file mode 100644
index 0000000..5c8ec4b
--- /dev/null
+++ b/Doc/library/strings.rst
@@ -0,0 +1,31 @@
+
+.. _stringservices:
+
+***************
+String Services
+***************
+
+The modules described in this chapter provide a wide range of string
+manipulation operations.
+
+In addition, Python's built-in string classes support the sequence type
+methods described in the :ref:`typesseq` section, and also the
+string-specific methods described in the :ref:`string-methods` section.
+To output formatted strings use template strings or the ``%`` operator
+described in the :ref:`string-formatting` section. Also, see the
+:mod:`re` module for string functions based on regular expressions.
+
+
+.. toctree::
+
+   string.rst
+   re.rst
+   struct.rst
+   difflib.rst
+   stringio.rst
+   textwrap.rst
+   codecs.rst
+   unicodedata.rst
+   stringprep.rst
+   fpformat.rst
+
diff --git a/Doc/library/struct.rst b/Doc/library/struct.rst
new file mode 100644
index 0000000..2f27d13
--- /dev/null
+++ b/Doc/library/struct.rst
@@ -0,0 +1,292 @@
+
+:mod:`struct` --- Interpret strings as packed binary data
+=========================================================
+
+.. module:: struct
+   :synopsis: Interpret strings as packed binary data.
+
+.. index::
+   pair: C; structures
+   triple: packing; binary; data
+
+This module performs conversions between Python values and C structs represented
+as Python strings.  It uses :dfn:`format strings` (explained below) as compact
+descriptions of the lay-out of the C structs and the intended conversion to/from
+Python values.  This can be used in handling binary data stored in files or from
+network connections, among other sources.
+
+The module defines the following exception and functions:
+
+
+.. exception:: error
+
+   Exception raised on various occasions; argument is a string describing what is
+   wrong.
+
+
+.. function:: pack(fmt, v1, v2, ...)
+
+   Return a string containing the values ``v1, v2, ...`` packed according to the
+   given format.  The arguments must match the values required by the format
+   exactly.
+
+
+.. function:: pack_into(fmt, buffer, offset, v1, v2, ...)
+
+   Pack the values ``v1, v2, ...`` according to the given format, write the packed
+   bytes into the writable *buffer* starting at *offset*. Note that the offset is
+   a required argument.
+
+   .. versionadded:: 2.5
+
+
+.. function:: unpack(fmt, string)
+
+   Unpack the string (presumably packed by ``pack(fmt, ...)``) according to the
+   given format.  The result is a tuple even if it contains exactly one item.  The
+   string must contain exactly the amount of data required by the format
+   (``len(string)`` must equal ``calcsize(fmt)``).
+
+
+.. function:: unpack_from(fmt, buffer[,offset=0])
+
+   Unpack the *buffer* according to tthe given format. The result is a tuple even
+   if it contains exactly one item. The *buffer* must contain at least the amount
+   of data required by the format (``len(buffer[offset:])`` must be at least
+   ``calcsize(fmt)``).
+
+   .. versionadded:: 2.5
+
+
+.. function:: calcsize(fmt)
+
+   Return the size of the struct (and hence of the string) corresponding to the
+   given format.
+
+Format characters have the following meaning; the conversion between C and
+Python values should be obvious given their types:
+
++--------+-------------------------+--------------------+-------+
+| Format | C Type                  | Python             | Notes |
++========+=========================+====================+=======+
+| ``x``  | pad byte                | no value           |       |
++--------+-------------------------+--------------------+-------+
+| ``c``  | :ctype:`char`           | string of length 1 |       |
++--------+-------------------------+--------------------+-------+
+| ``b``  | :ctype:`signed char`    | integer            |       |
++--------+-------------------------+--------------------+-------+
+| ``B``  | :ctype:`unsigned char`  | integer            |       |
++--------+-------------------------+--------------------+-------+
+| ``t``  | :ctype:`_Bool`          | bool               | \(1)  |
++--------+-------------------------+--------------------+-------+
+| ``h``  | :ctype:`short`          | integer            |       |
++--------+-------------------------+--------------------+-------+
+| ``H``  | :ctype:`unsigned short` | integer            |       |
++--------+-------------------------+--------------------+-------+
+| ``i``  | :ctype:`int`            | integer            |       |
++--------+-------------------------+--------------------+-------+
+| ``I``  | :ctype:`unsigned int`   | long               |       |
++--------+-------------------------+--------------------+-------+
+| ``l``  | :ctype:`long`           | integer            |       |
++--------+-------------------------+--------------------+-------+
+| ``L``  | :ctype:`unsigned long`  | long               |       |
++--------+-------------------------+--------------------+-------+
+| ``q``  | :ctype:`long long`      | long               | \(2)  |
++--------+-------------------------+--------------------+-------+
+| ``Q``  | :ctype:`unsigned long   | long               | \(2)  |
+|        | long`                   |                    |       |
++--------+-------------------------+--------------------+-------+
+| ``f``  | :ctype:`float`          | float              |       |
++--------+-------------------------+--------------------+-------+
+| ``d``  | :ctype:`double`         | float              |       |
++--------+-------------------------+--------------------+-------+
+| ``s``  | :ctype:`char[]`         | string             |       |
++--------+-------------------------+--------------------+-------+
+| ``p``  | :ctype:`char[]`         | string             |       |
++--------+-------------------------+--------------------+-------+
+| ``P``  | :ctype:`void \*`        | integer            |       |
++--------+-------------------------+--------------------+-------+
+
+Notes:
+
+(1)
+   The ``'t'`` conversion code corresponds to the :ctype:`_Bool` type defined by
+   C99. If this type is not available, it is simulated using a :ctype:`char`. In
+   standard mode, it is always represented by one byte.
+
+   .. versionadded:: 2.6
+
+(2)
+   The ``'q'`` and ``'Q'`` conversion codes are available in native mode only if
+   the platform C compiler supports C :ctype:`long long`, or, on Windows,
+   :ctype:`__int64`.  They are always available in standard modes.
+
+   .. versionadded:: 2.2
+
+A format character may be preceded by an integral repeat count.  For example,
+the format string ``'4h'`` means exactly the same as ``'hhhh'``.
+
+Whitespace characters between formats are ignored; a count and its format must
+not contain whitespace though.
+
+For the ``'s'`` format character, the count is interpreted as the size of the
+string, not a repeat count like for the other format characters; for example,
+``'10s'`` means a single 10-byte string, while ``'10c'`` means 10 characters.
+For packing, the string is truncated or padded with null bytes as appropriate to
+make it fit. For unpacking, the resulting string always has exactly the
+specified number of bytes.  As a special case, ``'0s'`` means a single, empty
+string (while ``'0c'`` means 0 characters).
+
+The ``'p'`` format character encodes a "Pascal string", meaning a short
+variable-length string stored in a fixed number of bytes. The count is the total
+number of bytes stored.  The first byte stored is the length of the string, or
+255, whichever is smaller.  The bytes of the string follow.  If the string
+passed in to :func:`pack` is too long (longer than the count minus 1), only the
+leading count-1 bytes of the string are stored.  If the string is shorter than
+count-1, it is padded with null bytes so that exactly count bytes in all are
+used.  Note that for :func:`unpack`, the ``'p'`` format character consumes count
+bytes, but that the string returned can never contain more than 255 characters.
+
+For the ``'I'``, ``'L'``, ``'q'`` and ``'Q'`` format characters, the return
+value is a Python long integer.
+
+For the ``'P'`` format character, the return value is a Python integer or long
+integer, depending on the size needed to hold a pointer when it has been cast to
+an integer type.  A *NULL* pointer will always be returned as the Python integer
+``0``. When packing pointer-sized values, Python integer or long integer objects
+may be used.  For example, the Alpha and Merced processors use 64-bit pointer
+values, meaning a Python long integer will be used to hold the pointer; other
+platforms use 32-bit pointers and will use a Python integer.
+
+For the ``'t'`` format character, the return value is either :const:`True` or
+:const:`False`. When packing, the truth value of the argument object is used.
+Either 0 or 1 in the native or standard bool representation will be packed, and
+any non-zero value will be True when unpacking.
+
+By default, C numbers are represented in the machine's native format and byte
+order, and properly aligned by skipping pad bytes if necessary (according to the
+rules used by the C compiler).
+
+Alternatively, the first character of the format string can be used to indicate
+the byte order, size and alignment of the packed data, according to the
+following table:
+
++-----------+------------------------+--------------------+
+| Character | Byte order             | Size and alignment |
++===========+========================+====================+
+| ``@``     | native                 | native             |
++-----------+------------------------+--------------------+
+| ``=``     | native                 | standard           |
++-----------+------------------------+--------------------+
+| ``<``     | little-endian          | standard           |
++-----------+------------------------+--------------------+
+| ``>``     | big-endian             | standard           |
++-----------+------------------------+--------------------+
+| ``!``     | network (= big-endian) | standard           |
++-----------+------------------------+--------------------+
+
+If the first character is not one of these, ``'@'`` is assumed.
+
+Native byte order is big-endian or little-endian, depending on the host system.
+For example, Motorola and Sun processors are big-endian; Intel and DEC
+processors are little-endian.
+
+Native size and alignment are determined using the C compiler's
+:keyword:`sizeof` expression.  This is always combined with native byte order.
+
+Standard size and alignment are as follows: no alignment is required for any
+type (so you have to use pad bytes); :ctype:`short` is 2 bytes; :ctype:`int` and
+:ctype:`long` are 4 bytes; :ctype:`long long` (:ctype:`__int64` on Windows) is 8
+bytes; :ctype:`float` and :ctype:`double` are 32-bit and 64-bit IEEE floating
+point numbers, respectively. :ctype:`_Bool` is 1 byte.
+
+Note the difference between ``'@'`` and ``'='``: both use native byte order, but
+the size and alignment of the latter is standardized.
+
+The form ``'!'`` is available for those poor souls who claim they can't remember
+whether network byte order is big-endian or little-endian.
+
+There is no way to indicate non-native byte order (force byte-swapping); use the
+appropriate choice of ``'<'`` or ``'>'``.
+
+The ``'P'`` format character is only available for the native byte ordering
+(selected as the default or with the ``'@'`` byte order character). The byte
+order character ``'='`` chooses to use little- or big-endian ordering based on
+the host system. The struct module does not interpret this as native ordering,
+so the ``'P'`` format is not available.
+
+Examples (all using native byte order, size and alignment, on a big-endian
+machine)::
+
+   >>> from struct import *
+   >>> pack('hhl', 1, 2, 3)
+   '\x00\x01\x00\x02\x00\x00\x00\x03'
+   >>> unpack('hhl', '\x00\x01\x00\x02\x00\x00\x00\x03')
+   (1, 2, 3)
+   >>> calcsize('hhl')
+   8
+
+Hint: to align the end of a structure to the alignment requirement of a
+particular type, end the format with the code for that type with a repeat count
+of zero.  For example, the format ``'llh0l'`` specifies two pad bytes at the
+end, assuming longs are aligned on 4-byte boundaries.  This only works when
+native size and alignment are in effect; standard size and alignment does not
+enforce any alignment.
+
+
+.. seealso::
+
+   Module :mod:`array`
+      Packed binary storage of homogeneous data.
+
+   Module :mod:`xdrlib`
+      Packing and unpacking of XDR data.
+
+
+.. _struct-objects:
+
+Struct Objects
+--------------
+
+The :mod:`struct` module also defines the following type:
+
+
+.. class:: Struct(format)
+
+   Return a new Struct object which writes and reads binary data according to the
+   format string *format*.  Creating a Struct object once and calling its methods
+   is more efficient than calling the :mod:`struct` functions with the same format
+   since the format string only needs to be compiled once.
+
+   .. versionadded:: 2.5
+
+Compiled Struct objects support the following methods and attributes:
+
+
+.. method:: Struct.pack(v1, v2, ...)
+
+   Identical to the :func:`pack` function, using the compiled format.
+   (``len(result)`` will equal :attr:`self.size`.)
+
+
+.. method:: Struct.pack_into(buffer, offset, v1, v2, ...)
+
+   Identical to the :func:`pack_into` function, using the compiled format.
+
+
+.. method:: Struct.unpack(string)
+
+   Identical to the :func:`unpack` function, using the compiled format.
+   (``len(string)`` must equal :attr:`self.size`).
+
+
+.. method:: Struct.unpack_from(buffer[, offset=0])
+
+   Identical to the :func:`unpack_from` function, using the compiled format.
+   (``len(buffer[offset:])`` must be at least :attr:`self.size`).
+
+
+.. attribute:: Struct.format
+
+   The format string used to construct this Struct object.
+
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
new file mode 100644
index 0000000..a3bc2cb
--- /dev/null
+++ b/Doc/library/subprocess.rst
@@ -0,0 +1,340 @@
+
+:mod:`subprocess` --- Subprocess management
+===========================================
+
+.. module:: subprocess
+   :synopsis: Subprocess management.
+.. moduleauthor:: Peter Åstrand <astrand@lysator.liu.se>
+.. sectionauthor:: Peter Åstrand <astrand@lysator.liu.se>
+
+
+.. versionadded:: 2.4
+
+The :mod:`subprocess` module allows you to spawn new processes, connect to their
+input/output/error pipes, and obtain their return codes.  This module intends to
+replace several other, older modules and functions, such as::
+
+   os.system
+   os.spawn*
+   commands.*
+
+Information about how the :mod:`subprocess` module can be used to replace these
+modules and functions can be found in the following sections.
+
+
+Using the subprocess Module
+---------------------------
+
+This module defines one class called :class:`Popen`:
+
+
+.. class:: Popen(args, bufsize=0, executable=None, stdin=None, stdout=None, stderr=None, preexec_fn=None, close_fds=False, shell=False, cwd=None, env=None, universal_newlines=False, startupinfo=None, creationflags=0)
+
+   Arguments are:
+
+   *args* should be a string, or a sequence of program arguments.  The program to
+   execute is normally the first item in the args sequence or string, but can be
+   explicitly set by using the executable argument.
+
+   On Unix, with *shell=False* (default): In this case, the Popen class uses
+   :meth:`os.execvp` to execute the child program. *args* should normally be a
+   sequence.  A string will be treated as a sequence with the string as the only
+   item (the program to execute).
+
+   On Unix, with *shell=True*: If args is a string, it specifies the command string
+   to execute through the shell.  If *args* is a sequence, the first item specifies
+   the command string, and any additional items will be treated as additional shell
+   arguments.
+
+   On Windows: the :class:`Popen` class uses CreateProcess() to execute the child
+   program, which operates on strings.  If *args* is a sequence, it will be
+   converted to a string using the :meth:`list2cmdline` method.  Please note that
+   not all MS Windows applications interpret the command line the same way:
+   :meth:`list2cmdline` is designed for applications using the same rules as the MS
+   C runtime.
+
+   *bufsize*, if given, has the same meaning as the corresponding argument to the
+   built-in open() function: :const:`0` means unbuffered, :const:`1` means line
+   buffered, any other positive value means use a buffer of (approximately) that
+   size.  A negative *bufsize* means to use the system default, which usually means
+   fully buffered.  The default value for *bufsize* is :const:`0` (unbuffered).
+
+   The *executable* argument specifies the program to execute. It is very seldom
+   needed: Usually, the program to execute is defined by the *args* argument. If
+   ``shell=True``, the *executable* argument specifies which shell to use. On Unix,
+   the default shell is :file:`/bin/sh`.  On Windows, the default shell is
+   specified by the :envvar:`COMSPEC` environment variable.
+
+   *stdin*, *stdout* and *stderr* specify the executed programs' standard input,
+   standard output and standard error file handles, respectively.  Valid values are
+   ``PIPE``, an existing file descriptor (a positive integer), an existing file
+   object, and ``None``.  ``PIPE`` indicates that a new pipe to the child should be
+   created.  With ``None``, no redirection will occur; the child's file handles
+   will be inherited from the parent.  Additionally, *stderr* can be ``STDOUT``,
+   which indicates that the stderr data from the applications should be captured
+   into the same file handle as for stdout.
+
+   If *preexec_fn* is set to a callable object, this object will be called in the
+   child process just before the child is executed. (Unix only)
+
+   If *close_fds* is true, all file descriptors except :const:`0`, :const:`1` and
+   :const:`2` will be closed before the child process is executed. (Unix only).
+   Or, on Windows, if *close_fds* is true then no handles will be inherited by the
+   child process.  Note that on Windows, you cannot set *close_fds* to true and
+   also redirect the standard handles by setting *stdin*, *stdout* or *stderr*.
+
+   If *shell* is :const:`True`, the specified command will be executed through the
+   shell.
+
+   If *cwd* is not ``None``, the child's current directory will be changed to *cwd*
+   before it is executed.  Note that this directory is not considered when
+   searching the executable, so you can't specify the program's path relative to
+   *cwd*.
+
+   If *env* is not ``None``, it defines the environment variables for the new
+   process.
+
+   If *universal_newlines* is :const:`True`, the file objects stdout and stderr are
+   opened as text files, but lines may be terminated by any of ``'\n'``, the Unix
+   end-of-line convention, ``'\r'``, the Macintosh convention or ``'\r\n'``, the
+   Windows convention. All of these external representations are seen as ``'\n'``
+   by the Python program.
+
+   .. note::
+
+      This feature is only available if Python is built with universal newline support
+      (the default).  Also, the newlines attribute of the file objects :attr:`stdout`,
+      :attr:`stdin` and :attr:`stderr` are not updated by the communicate() method.
+
+   The *startupinfo* and *creationflags*, if given, will be passed to the
+   underlying CreateProcess() function.  They can specify things such as appearance
+   of the main window and priority for the new process.  (Windows only)
+
+
+Convenience Functions
+^^^^^^^^^^^^^^^^^^^^^
+
+This module also defines two shortcut functions:
+
+
+.. function:: call(*popenargs, **kwargs)
+
+   Run command with arguments.  Wait for command to complete, then return the
+   :attr:`returncode` attribute.
+
+   The arguments are the same as for the Popen constructor.  Example::
+
+      retcode = call(["ls", "-l"])
+
+
+.. function:: check_call(*popenargs, **kwargs)
+
+   Run command with arguments.  Wait for command to complete. If the exit code was
+   zero then return, otherwise raise :exc:`CalledProcessError.` The
+   :exc:`CalledProcessError` object will have the return code in the
+   :attr:`returncode` attribute.
+
+   The arguments are the same as for the Popen constructor.  Example::
+
+      check_call(["ls", "-l"])
+
+   .. versionadded:: 2.5
+
+
+Exceptions
+^^^^^^^^^^
+
+Exceptions raised in the child process, before the new program has started to
+execute, will be re-raised in the parent.  Additionally, the exception object
+will have one extra attribute called :attr:`child_traceback`, which is a string
+containing traceback information from the childs point of view.
+
+The most common exception raised is :exc:`OSError`.  This occurs, for example,
+when trying to execute a non-existent file.  Applications should prepare for
+:exc:`OSError` exceptions.
+
+A :exc:`ValueError` will be raised if :class:`Popen` is called with invalid
+arguments.
+
+check_call() will raise :exc:`CalledProcessError`, if the called process returns
+a non-zero return code.
+
+
+Security
+^^^^^^^^
+
+Unlike some other popen functions, this implementation will never call /bin/sh
+implicitly.  This means that all characters, including shell metacharacters, can
+safely be passed to child processes.
+
+
+Popen Objects
+-------------
+
+Instances of the :class:`Popen` class have the following methods:
+
+
+.. method:: Popen.poll()
+
+   Check if child process has terminated.  Returns returncode attribute.
+
+
+.. method:: Popen.wait()
+
+   Wait for child process to terminate.  Returns returncode attribute.
+
+
+.. method:: Popen.communicate(input=None)
+
+   Interact with process: Send data to stdin.  Read data from stdout and stderr,
+   until end-of-file is reached.  Wait for process to terminate. The optional
+   *input* argument should be a string to be sent to the child process, or
+   ``None``, if no data should be sent to the child.
+
+   communicate() returns a tuple (stdout, stderr).
+
+   .. note::
+
+      The data read is buffered in memory, so do not use this method if the data size
+      is large or unlimited.
+
+The following attributes are also available:
+
+
+.. attribute:: Popen.stdin
+
+   If the *stdin* argument is ``PIPE``, this attribute is a file object that
+   provides input to the child process.  Otherwise, it is ``None``.
+
+
+.. attribute:: Popen.stdout
+
+   If the *stdout* argument is ``PIPE``, this attribute is a file object that
+   provides output from the child process.  Otherwise, it is ``None``.
+
+
+.. attribute:: Popen.stderr
+
+   If the *stderr* argument is ``PIPE``, this attribute is file object that
+   provides error output from the child process.  Otherwise, it is ``None``.
+
+
+.. attribute:: Popen.pid
+
+   The process ID of the child process.
+
+
+.. attribute:: Popen.returncode
+
+   The child return code.  A ``None`` value indicates that the process hasn't
+   terminated yet.  A negative value -N indicates that the child was terminated by
+   signal N (Unix only).
+
+
+Replacing Older Functions with the subprocess Module
+----------------------------------------------------
+
+In this section, "a ==> b" means that b can be used as a replacement for a.
+
+.. note::
+
+   All functions in this section fail (more or less) silently if the executed
+   program cannot be found; this module raises an :exc:`OSError` exception.
+
+In the following examples, we assume that the subprocess module is imported with
+"from subprocess import \*".
+
+
+Replacing /bin/sh shell backquote
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+::
+
+   output=`mycmd myarg`
+   ==>
+   output = Popen(["mycmd", "myarg"], stdout=PIPE).communicate()[0]
+
+
+Replacing shell pipe line
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+::
+
+   output=`dmesg | grep hda`
+   ==>
+   p1 = Popen(["dmesg"], stdout=PIPE)
+   p2 = Popen(["grep", "hda"], stdin=p1.stdout, stdout=PIPE)
+   output = p2.communicate()[0]
+
+
+Replacing os.system()
+^^^^^^^^^^^^^^^^^^^^^
+
+::
+
+   sts = os.system("mycmd" + " myarg")
+   ==>
+   p = Popen("mycmd" + " myarg", shell=True)
+   sts = os.waitpid(p.pid, 0)
+
+Notes:
+
+* Calling the program through the shell is usually not required.
+
+* It's easier to look at the :attr:`returncode` attribute than the exit status.
+
+A more realistic example would look like this::
+
+   try:
+       retcode = call("mycmd" + " myarg", shell=True)
+       if retcode < 0:
+           print >>sys.stderr, "Child was terminated by signal", -retcode
+       else:
+           print >>sys.stderr, "Child returned", retcode
+   except OSError as e:
+       print >>sys.stderr, "Execution failed:", e
+
+
+Replacing os.spawn\*
+^^^^^^^^^^^^^^^^^^^^
+
+P_NOWAIT example::
+
+   pid = os.spawnlp(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg")
+   ==>
+   pid = Popen(["/bin/mycmd", "myarg"]).pid
+
+P_WAIT example::
+
+   retcode = os.spawnlp(os.P_WAIT, "/bin/mycmd", "mycmd", "myarg")
+   ==>
+   retcode = call(["/bin/mycmd", "myarg"])
+
+Vector example::
+
+   os.spawnvp(os.P_NOWAIT, path, args)
+   ==>
+   Popen([path] + args[1:])
+
+Environment example::
+
+   os.spawnlpe(os.P_NOWAIT, "/bin/mycmd", "mycmd", "myarg", env)
+   ==>
+   Popen(["/bin/mycmd", "myarg"], env={"PATH": "/usr/bin"})
+
+
+Replacing os.popen\*
+^^^^^^^^^^^^^^^^^^^^
+
+::
+
+   pipe = os.popen(cmd, mode='r', bufsize)
+   ==>
+   pipe = Popen(cmd, shell=True, bufsize=bufsize, stdout=PIPE).stdout
+
+::
+
+   pipe = os.popen(cmd, mode='w', bufsize)
+   ==>
+   pipe = Popen(cmd, shell=True, bufsize=bufsize, stdin=PIPE).stdin
+
diff --git a/Doc/library/sunau.rst b/Doc/library/sunau.rst
new file mode 100644
index 0000000..9930133
--- /dev/null
+++ b/Doc/library/sunau.rst
@@ -0,0 +1,261 @@
+
+:mod:`sunau` --- Read and write Sun AU files
+============================================
+
+.. module:: sunau
+   :synopsis: Provide an interface to the Sun AU sound format.
+.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
+
+
+The :mod:`sunau` module provides a convenient interface to the Sun AU sound
+format.  Note that this module is interface-compatible with the modules
+:mod:`aifc` and :mod:`wave`.
+
+An audio file consists of a header followed by the data.  The fields of the
+header are:
+
++---------------+-----------------------------------------------+
+| Field         | Contents                                      |
++===============+===============================================+
+| magic word    | The four bytes ``.snd``.                      |
++---------------+-----------------------------------------------+
+| header size   | Size of the header, including info, in bytes. |
++---------------+-----------------------------------------------+
+| data size     | Physical size of the data, in bytes.          |
++---------------+-----------------------------------------------+
+| encoding      | Indicates how the audio samples are encoded.  |
++---------------+-----------------------------------------------+
+| sample rate   | The sampling rate.                            |
++---------------+-----------------------------------------------+
+| # of channels | The number of channels in the samples.        |
++---------------+-----------------------------------------------+
+| info          | ASCII string giving a description of the      |
+|               | audio file (padded with null bytes).          |
++---------------+-----------------------------------------------+
+
+Apart from the info field, all header fields are 4 bytes in size. They are all
+32-bit unsigned integers encoded in big-endian byte order.
+
+The :mod:`sunau` module defines the following functions:
+
+
+.. function:: open(file, mode)
+
+   If *file* is a string, open the file by that name, otherwise treat it as a
+   seekable file-like object. *mode* can be any of
+
+   ``'r'``
+      Read only mode.
+
+   ``'w'``
+      Write only mode.
+
+   Note that it does not allow read/write files.
+
+   A *mode* of ``'r'`` returns a :class:`AU_read` object, while a *mode* of ``'w'``
+   or ``'wb'`` returns a :class:`AU_write` object.
+
+
+.. function:: openfp(file, mode)
+
+   A synonym for :func:`open`, maintained for backwards compatibility.
+
+The :mod:`sunau` module defines the following exception:
+
+
+.. exception:: Error
+
+   An error raised when something is impossible because of Sun AU specs or
+   implementation deficiency.
+
+The :mod:`sunau` module defines the following data items:
+
+
+.. data:: AUDIO_FILE_MAGIC
+
+   An integer every valid Sun AU file begins with, stored in big-endian form.  This
+   is the string ``.snd`` interpreted as an integer.
+
+
+.. data:: AUDIO_FILE_ENCODING_MULAW_8
+          AUDIO_FILE_ENCODING_LINEAR_8
+          AUDIO_FILE_ENCODING_LINEAR_16
+          AUDIO_FILE_ENCODING_LINEAR_24
+          AUDIO_FILE_ENCODING_LINEAR_32
+          AUDIO_FILE_ENCODING_ALAW_8
+
+   Values of the encoding field from the AU header which are supported by this
+   module.
+
+
+.. data:: AUDIO_FILE_ENCODING_FLOAT
+          AUDIO_FILE_ENCODING_DOUBLE
+          AUDIO_FILE_ENCODING_ADPCM_G721
+          AUDIO_FILE_ENCODING_ADPCM_G722
+          AUDIO_FILE_ENCODING_ADPCM_G723_3
+          AUDIO_FILE_ENCODING_ADPCM_G723_5
+
+   Additional known values of the encoding field from the AU header, but which are
+   not supported by this module.
+
+
+.. _au-read-objects:
+
+AU_read Objects
+---------------
+
+AU_read objects, as returned by :func:`open` above, have the following methods:
+
+
+.. method:: AU_read.close()
+
+   Close the stream, and make the instance unusable. (This is  called automatically
+   on deletion.)
+
+
+.. method:: AU_read.getnchannels()
+
+   Returns number of audio channels (1 for mone, 2 for stereo).
+
+
+.. method:: AU_read.getsampwidth()
+
+   Returns sample width in bytes.
+
+
+.. method:: AU_read.getframerate()
+
+   Returns sampling frequency.
+
+
+.. method:: AU_read.getnframes()
+
+   Returns number of audio frames.
+
+
+.. method:: AU_read.getcomptype()
+
+   Returns compression type. Supported compression types are ``'ULAW'``, ``'ALAW'``
+   and ``'NONE'``.
+
+
+.. method:: AU_read.getcompname()
+
+   Human-readable version of :meth:`getcomptype`.  The supported types have the
+   respective names ``'CCITT G.711 u-law'``, ``'CCITT G.711 A-law'`` and ``'not
+   compressed'``.
+
+
+.. method:: AU_read.getparams()
+
+   Returns a tuple ``(nchannels, sampwidth, framerate, nframes, comptype,
+   compname)``, equivalent to output of the :meth:`get\*` methods.
+
+
+.. method:: AU_read.readframes(n)
+
+   Reads and returns at most *n* frames of audio, as a string of bytes.  The data
+   will be returned in linear format.  If the original data is in u-LAW format, it
+   will be converted.
+
+
+.. method:: AU_read.rewind()
+
+   Rewind the file pointer to the beginning of the audio stream.
+
+The following two methods define a term "position" which is compatible between
+them, and is otherwise implementation dependent.
+
+
+.. method:: AU_read.setpos(pos)
+
+   Set the file pointer to the specified position.  Only values returned from
+   :meth:`tell` should be used for *pos*.
+
+
+.. method:: AU_read.tell()
+
+   Return current file pointer position.  Note that the returned value has nothing
+   to do with the actual position in the file.
+
+The following two functions are defined for compatibility with the  :mod:`aifc`,
+and don't do anything interesting.
+
+
+.. method:: AU_read.getmarkers()
+
+   Returns ``None``.
+
+
+.. method:: AU_read.getmark(id)
+
+   Raise an error.
+
+
+.. _au-write-objects:
+
+AU_write Objects
+----------------
+
+AU_write objects, as returned by :func:`open` above, have the following methods:
+
+
+.. method:: AU_write.setnchannels(n)
+
+   Set the number of channels.
+
+
+.. method:: AU_write.setsampwidth(n)
+
+   Set the sample width (in bytes.)
+
+
+.. method:: AU_write.setframerate(n)
+
+   Set the frame rate.
+
+
+.. method:: AU_write.setnframes(n)
+
+   Set the number of frames. This can be later changed, when and if more  frames
+   are written.
+
+
+.. method:: AU_write.setcomptype(type, name)
+
+   Set the compression type and description. Only ``'NONE'`` and ``'ULAW'`` are
+   supported on output.
+
+
+.. method:: AU_write.setparams(tuple)
+
+   The *tuple* should be ``(nchannels, sampwidth, framerate, nframes, comptype,
+   compname)``, with values valid for the :meth:`set\*` methods.  Set all
+   parameters.
+
+
+.. method:: AU_write.tell()
+
+   Return current position in the file, with the same disclaimer for the
+   :meth:`AU_read.tell` and :meth:`AU_read.setpos` methods.
+
+
+.. method:: AU_write.writeframesraw(data)
+
+   Write audio frames, without correcting *nframes*.
+
+
+.. method:: AU_write.writeframes(data)
+
+   Write audio frames and make sure *nframes* is correct.
+
+
+.. method:: AU_write.close()
+
+   Make sure *nframes* is correct, and close the file.
+
+   This method is called upon deletion.
+
+Note that it is invalid to set any parameters after calling  :meth:`writeframes`
+or :meth:`writeframesraw`.
+
diff --git a/Doc/library/symbol.rst b/Doc/library/symbol.rst
new file mode 100644
index 0000000..1735276
--- /dev/null
+++ b/Doc/library/symbol.rst
@@ -0,0 +1,32 @@
+
+:mod:`symbol` --- Constants used with Python parse trees
+========================================================
+
+.. module:: symbol
+   :synopsis: Constants representing internal nodes of the parse tree.
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+This module provides constants which represent the numeric values of internal
+nodes of the parse tree.  Unlike most Python constants, these use lower-case
+names.  Refer to the file :file:`Grammar/Grammar` in the Python distribution for
+the definitions of the names in the context of the language grammar.  The
+specific numeric values which the names map to may change between Python
+versions.
+
+This module also provides one additional data object:
+
+
+.. data:: sym_name
+
+   Dictionary mapping the numeric values of the constants defined in this module
+   back to name strings, allowing more human-readable representation of parse trees
+   to be generated.
+
+
+.. seealso::
+
+   Module :mod:`parser`
+      The second example for the :mod:`parser` module shows how to use the
+      :mod:`symbol` module.
+
diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
new file mode 100644
index 0000000..5184c25
--- /dev/null
+++ b/Doc/library/sys.rst
@@ -0,0 +1,606 @@
+
+:mod:`sys` --- System-specific parameters and functions
+=======================================================
+
+.. module:: sys
+   :synopsis: Access system-specific parameters and functions.
+
+
+This module provides access to some variables used or maintained by the
+interpreter and to functions that interact strongly with the interpreter. It is
+always available.
+
+
+.. data:: argv
+
+   The list of command line arguments passed to a Python script. ``argv[0]`` is the
+   script name (it is operating system dependent whether this is a full pathname or
+   not).  If the command was executed using the :option:`-c` command line option to
+   the interpreter, ``argv[0]`` is set to the string ``'-c'``.  If no script name
+   was passed to the Python interpreter, ``argv[0]`` is the empty string.
+
+   To loop over the standard input, or the list of files given on the
+   command line, see the :mod:`fileinput` module.
+
+
+.. data:: byteorder
+
+   An indicator of the native byte order.  This will have the value ``'big'`` on
+   big-endian (most-significant byte first) platforms, and ``'little'`` on
+   little-endian (least-significant byte first) platforms.
+
+   .. versionadded:: 2.0
+
+
+.. data:: subversion
+
+   A triple (repo, branch, version) representing the Subversion information of the
+   Python interpreter. *repo* is the name of the repository, ``'CPython'``.
+   *branch* is a string of one of the forms ``'trunk'``, ``'branches/name'`` or
+   ``'tags/name'``. *version* is the output of ``svnversion``, if the interpreter
+   was built from a Subversion checkout; it contains the revision number (range)
+   and possibly a trailing 'M' if there were local modifications. If the tree was
+   exported (or svnversion was not available), it is the revision of
+   ``Include/patchlevel.h`` if the branch is a tag. Otherwise, it is ``None``.
+
+   .. versionadded:: 2.5
+
+
+.. data:: builtin_module_names
+
+   A tuple of strings giving the names of all modules that are compiled into this
+   Python interpreter.  (This information is not available in any other way ---
+   ``modules.keys()`` only lists the imported modules.)
+
+
+.. data:: copyright
+
+   A string containing the copyright pertaining to the Python interpreter.
+
+
+.. function:: _current_frames()
+
+   Return a dictionary mapping each thread's identifier to the topmost stack frame
+   currently active in that thread at the time the function is called. Note that
+   functions in the :mod:`traceback` module can build the call stack given such a
+   frame.
+
+   This is most useful for debugging deadlock:  this function does not require the
+   deadlocked threads' cooperation, and such threads' call stacks are frozen for as
+   long as they remain deadlocked.  The frame returned for a non-deadlocked thread
+   may bear no relationship to that thread's current activity by the time calling
+   code examines the frame.
+
+   This function should be used for internal and specialized purposes only.
+
+   .. versionadded:: 2.5
+
+
+.. data:: dllhandle
+
+   Integer specifying the handle of the Python DLL. Availability: Windows.
+
+
+.. function:: displayhook(value)
+
+   If *value* is not ``None``, this function prints it to ``sys.stdout``, and saves
+   it in ``__builtin__._``.
+
+   ``sys.displayhook`` is called on the result of evaluating an expression entered
+   in an interactive Python session.  The display of these values can be customized
+   by assigning another one-argument function to ``sys.displayhook``.
+
+
+.. function:: excepthook(type, value, traceback)
+
+   This function prints out a given traceback and exception to ``sys.stderr``.
+
+   When an exception is raised and uncaught, the interpreter calls
+   ``sys.excepthook`` with three arguments, the exception class, exception
+   instance, and a traceback object.  In an interactive session this happens just
+   before control is returned to the prompt; in a Python program this happens just
+   before the program exits.  The handling of such top-level exceptions can be
+   customized by assigning another three-argument function to ``sys.excepthook``.
+
+
+.. data:: __displayhook__
+          __excepthook__
+
+   These objects contain the original values of ``displayhook`` and ``excepthook``
+   at the start of the program.  They are saved so that ``displayhook`` and
+   ``excepthook`` can be restored in case they happen to get replaced with broken
+   objects.
+
+
+.. function:: exc_info()
+
+   This function returns a tuple of three values that give information about the
+   exception that is currently being handled.  The information returned is specific
+   both to the current thread and to the current stack frame.  If the current stack
+   frame is not handling an exception, the information is taken from the calling
+   stack frame, or its caller, and so on until a stack frame is found that is
+   handling an exception.  Here, "handling an exception" is defined as "executing
+   or having executed an except clause."  For any stack frame, only information
+   about the most recently handled exception is accessible.
+
+   .. index:: object: traceback
+
+   If no exception is being handled anywhere on the stack, a tuple containing three
+   ``None`` values is returned.  Otherwise, the values returned are ``(type, value,
+   traceback)``.  Their meaning is: *type* gets the exception type of the exception
+   being handled (a class object); *value* gets the exception parameter (its
+   :dfn:`associated value` or the second argument to :keyword:`raise`, which is
+   always a class instance if the exception type is a class object); *traceback*
+   gets a traceback object (see the Reference Manual) which encapsulates the call
+   stack at the point where the exception originally occurred.
+
+   .. warning::
+
+      Assigning the *traceback* return value to a local variable in a function that is
+      handling an exception will cause a circular reference.  This will prevent
+      anything referenced by a local variable in the same function or by the traceback
+      from being garbage collected.  Since most functions don't need access to the
+      traceback, the best solution is to use something like ``exctype, value =
+      sys.exc_info()[:2]`` to extract only the exception type and value.  If you do
+      need the traceback, make sure to delete it after use (best done with a
+      :keyword:`try` ... :keyword:`finally` statement) or to call :func:`exc_info` in
+      a function that does not itself handle an exception.
+
+   .. note::
+
+      Beginning with Python 2.2, such cycles are automatically reclaimed when garbage
+      collection is enabled and they become unreachable, but it remains more efficient
+      to avoid creating cycles.
+
+
+.. data:: exec_prefix
+
+   A string giving the site-specific directory prefix where the platform-dependent
+   Python files are installed; by default, this is also ``'/usr/local'``.  This can
+   be set at build time with the :option:`--exec-prefix` argument to the
+   :program:`configure` script.  Specifically, all configuration files (e.g. the
+   :file:`pyconfig.h` header file) are installed in the directory ``exec_prefix +
+   '/lib/pythonversion/config'``, and shared library modules are installed in
+   ``exec_prefix + '/lib/pythonversion/lib-dynload'``, where *version* is equal to
+   ``version[:3]``.
+
+
+.. data:: executable
+
+   A string giving the name of the executable binary for the Python interpreter, on
+   systems where this makes sense.
+
+
+.. function:: exit([arg])
+
+   Exit from Python.  This is implemented by raising the :exc:`SystemExit`
+   exception, so cleanup actions specified by finally clauses of :keyword:`try`
+   statements are honored, and it is possible to intercept the exit attempt at an
+   outer level.  The optional argument *arg* can be an integer giving the exit
+   status (defaulting to zero), or another type of object.  If it is an integer,
+   zero is considered "successful termination" and any nonzero value is considered
+   "abnormal termination" by shells and the like.  Most systems require it to be in
+   the range 0-127, and produce undefined results otherwise.  Some systems have a
+   convention for assigning specific meanings to specific exit codes, but these are
+   generally underdeveloped; Unix programs generally use 2 for command line syntax
+   errors and 1 for all other kind of errors.  If another type of object is passed,
+   ``None`` is equivalent to passing zero, and any other object is printed to
+   ``sys.stderr`` and results in an exit code of 1.  In particular,
+   ``sys.exit("some error message")`` is a quick way to exit a program when an
+   error occurs.
+
+
+.. function:: getcheckinterval()
+
+   Return the interpreter's "check interval"; see :func:`setcheckinterval`.
+
+   .. versionadded:: 2.3
+
+
+.. function:: getdefaultencoding()
+
+   Return the name of the current default string encoding used by the Unicode
+   implementation.
+
+   .. versionadded:: 2.0
+
+
+.. function:: getdlopenflags()
+
+   Return the current value of the flags that are used for :cfunc:`dlopen` calls.
+   The flag constants are defined in the :mod:`dl` and :mod:`DLFCN` modules.
+   Availability: Unix.
+
+   .. versionadded:: 2.2
+
+
+.. function:: getfilesystemencoding()
+
+   Return the name of the encoding used to convert Unicode filenames into system
+   file names, or ``None`` if the system default encoding is used. The result value
+   depends on the operating system:
+
+   * On Windows 9x, the encoding is "mbcs".
+
+   * On Mac OS X, the encoding is "utf-8".
+
+   * On Unix, the encoding is the user's preference according to the result of
+     nl_langinfo(CODESET), or :const:`None` if the ``nl_langinfo(CODESET)`` failed.
+
+   * On Windows NT+, file names are Unicode natively, so no conversion is
+     performed. :func:`getfilesystemencoding` still returns ``'mbcs'``, as this is
+     the encoding that applications should use when they explicitly want to convert
+     Unicode strings to byte strings that are equivalent when used as file names.
+
+   .. versionadded:: 2.3
+
+
+.. function:: getrefcount(object)
+
+   Return the reference count of the *object*.  The count returned is generally one
+   higher than you might expect, because it includes the (temporary) reference as
+   an argument to :func:`getrefcount`.
+
+
+.. function:: getrecursionlimit()
+
+   Return the current value of the recursion limit, the maximum depth of the Python
+   interpreter stack.  This limit prevents infinite recursion from causing an
+   overflow of the C stack and crashing Python.  It can be set by
+   :func:`setrecursionlimit`.
+
+
+.. function:: _getframe([depth])
+
+   Return a frame object from the call stack.  If optional integer *depth* is
+   given, return the frame object that many calls below the top of the stack.  If
+   that is deeper than the call stack, :exc:`ValueError` is raised.  The default
+   for *depth* is zero, returning the frame at the top of the call stack.
+
+   This function should be used for internal and specialized purposes only.
+
+
+.. function:: getwindowsversion()
+
+   Return a tuple containing five components, describing the Windows version
+   currently running.  The elements are *major*, *minor*, *build*, *platform*, and
+   *text*.  *text* contains a string while all other values are integers.
+
+   *platform* may be one of the following values:
+
+   +-----------------------------------------+-----------------------+
+   | Constant                                | Platform              |
+   +=========================================+=======================+
+   | :const:`0 (VER_PLATFORM_WIN32s)`        | Win32s on Windows 3.1 |
+   +-----------------------------------------+-----------------------+
+   | :const:`1 (VER_PLATFORM_WIN32_WINDOWS)` | Windows 95/98/ME      |
+   +-----------------------------------------+-----------------------+
+   | :const:`2 (VER_PLATFORM_WIN32_NT)`      | Windows NT/2000/XP    |
+   +-----------------------------------------+-----------------------+
+   | :const:`3 (VER_PLATFORM_WIN32_CE)`      | Windows CE            |
+   +-----------------------------------------+-----------------------+
+
+   This function wraps the Win32 :cfunc:`GetVersionEx` function; see the Microsoft
+   documentation for more information about these fields.
+
+   Availability: Windows.
+
+   .. versionadded:: 2.3
+
+
+.. data:: hexversion
+
+   The version number encoded as a single integer.  This is guaranteed to increase
+   with each version, including proper support for non-production releases.  For
+   example, to test that the Python interpreter is at least version 1.5.2, use::
+
+      if sys.hexversion >= 0x010502F0:
+          # use some advanced feature
+          ...
+      else:
+          # use an alternative implementation or warn the user
+          ...
+
+   This is called ``hexversion`` since it only really looks meaningful when viewed
+   as the result of passing it to the built-in :func:`hex` function.  The
+   ``version_info`` value may be used for a more human-friendly encoding of the
+   same information.
+
+   .. versionadded:: 1.5.2
+
+
+.. function:: intern(string)
+
+   Enter *string* in the table of "interned" strings and return the interned string
+   -- which is *string* itself or a copy. Interning strings is useful to gain a
+   little performance on dictionary lookup -- if the keys in a dictionary are
+   interned, and the lookup key is interned, the key comparisons (after hashing)
+   can be done by a pointer compare instead of a string compare.  Normally, the
+   names used in Python programs are automatically interned, and the dictionaries
+   used to hold module, class or instance attributes have interned keys.
+
+   .. versionchanged:: 2.3
+      Interned strings are not immortal (like they used to be in Python 2.2 and
+      before); you must keep a reference to the return value of :func:`intern` around
+      to benefit from it.
+
+
+.. data:: last_type
+          last_value
+          last_traceback
+
+   These three variables are not always defined; they are set when an exception is
+   not handled and the interpreter prints an error message and a stack traceback.
+   Their intended use is to allow an interactive user to import a debugger module
+   and engage in post-mortem debugging without having to re-execute the command
+   that caused the error.  (Typical use is ``import pdb; pdb.pm()`` to enter the
+   post-mortem debugger; see chapter :ref:`debugger` for
+   more information.)
+
+   The meaning of the variables is the same as that of the return values from
+   :func:`exc_info` above.  (Since there is only one interactive thread,
+   thread-safety is not a concern for these variables, unlike for ``exc_type``
+   etc.)
+
+
+.. data:: maxint
+
+   The largest positive integer supported by Python's regular integer type.  This
+   is at least 2\*\*31-1.  The largest negative integer is ``-maxint-1`` --- the
+   asymmetry results from the use of 2's complement binary arithmetic.
+
+
+.. data:: maxunicode
+
+   An integer giving the largest supported code point for a Unicode character.  The
+   value of this depends on the configuration option that specifies whether Unicode
+   characters are stored as UCS-2 or UCS-4.
+
+
+.. data:: modules
+
+   This is a dictionary that maps module names to modules which have already been
+   loaded.  This can be manipulated to force reloading of modules and other tricks.
+
+
+.. data:: path
+
+   .. index:: triple: module; search; path
+
+   A list of strings that specifies the search path for modules. Initialized from
+   the environment variable :envvar:`PYTHONPATH`, plus an installation-dependent
+   default.
+
+   As initialized upon program startup, the first item of this list, ``path[0]``,
+   is the directory containing the script that was used to invoke the Python
+   interpreter.  If the script directory is not available (e.g.  if the interpreter
+   is invoked interactively or if the script is read from standard input),
+   ``path[0]`` is the empty string, which directs Python to search modules in the
+   current directory first.  Notice that the script directory is inserted *before*
+   the entries inserted as a result of :envvar:`PYTHONPATH`.
+
+   A program is free to modify this list for its own purposes.
+
+   .. versionchanged:: 2.3
+      Unicode strings are no longer ignored.
+
+
+.. data:: platform
+
+   This string contains a platform identifier, e.g. ``'sunos5'`` or ``'linux1'``.
+   This can be used to append platform-specific components to ``path``, for
+   instance.
+
+
+.. data:: prefix
+
+   A string giving the site-specific directory prefix where the platform
+   independent Python files are installed; by default, this is the string
+   ``'/usr/local'``.  This can be set at build time with the :option:`--prefix`
+   argument to the :program:`configure` script.  The main collection of Python
+   library modules is installed in the directory ``prefix + '/lib/pythonversion'``
+   while the platform independent header files (all except :file:`pyconfig.h`) are
+   stored in ``prefix + '/include/pythonversion'``, where *version* is equal to
+   ``version[:3]``.
+
+
+.. data:: ps1
+          ps2
+
+   .. index::
+      single: interpreter prompts
+      single: prompts, interpreter
+
+   Strings specifying the primary and secondary prompt of the interpreter.  These
+   are only defined if the interpreter is in interactive mode.  Their initial
+   values in this case are ``'>>> '`` and ``'... '``.  If a non-string object is
+   assigned to either variable, its :func:`str` is re-evaluated each time the
+   interpreter prepares to read a new interactive command; this can be used to
+   implement a dynamic prompt.
+
+
+.. function:: setcheckinterval(interval)
+
+   Set the interpreter's "check interval".  This integer value determines how often
+   the interpreter checks for periodic things such as thread switches and signal
+   handlers.  The default is ``100``, meaning the check is performed every 100
+   Python virtual instructions. Setting it to a larger value may increase
+   performance for programs using threads.  Setting it to a value ``<=`` 0 checks
+   every virtual instruction, maximizing responsiveness as well as overhead.
+
+
+.. function:: setdefaultencoding(name)
+
+   Set the current default string encoding used by the Unicode implementation.  If
+   *name* does not match any available encoding, :exc:`LookupError` is raised.
+   This function is only intended to be used by the :mod:`site` module
+   implementation and, where needed, by :mod:`sitecustomize`.  Once used by the
+   :mod:`site` module, it is removed from the :mod:`sys` module's namespace.
+
+   .. % Note that \refmodule{site} is not imported if
+   .. % the \programopt{-S} option is passed to the interpreter, in which
+   .. % case this function will remain available.
+
+   .. versionadded:: 2.0
+
+
+.. function:: setdlopenflags(n)
+
+   Set the flags used by the interpreter for :cfunc:`dlopen` calls, such as when
+   the interpreter loads extension modules.  Among other things, this will enable a
+   lazy resolving of symbols when importing a module, if called as
+   ``sys.setdlopenflags(0)``.  To share symbols across extension modules, call as
+   ``sys.setdlopenflags(dl.RTLD_NOW | dl.RTLD_GLOBAL)``.  Symbolic names for the
+   flag modules can be either found in the :mod:`dl` module, or in the :mod:`DLFCN`
+   module. If :mod:`DLFCN` is not available, it can be generated from
+   :file:`/usr/include/dlfcn.h` using the :program:`h2py` script. Availability:
+   Unix.
+
+   .. versionadded:: 2.2
+
+
+.. function:: setprofile(profilefunc)
+
+   .. index::
+      single: profile function
+      single: profiler
+
+   Set the system's profile function, which allows you to implement a Python source
+   code profiler in Python.  See chapter :ref:`profile` for more information on the
+   Python profiler.  The system's profile function is called similarly to the
+   system's trace function (see :func:`settrace`), but it isn't called for each
+   executed line of code (only on call and return, but the return event is reported
+   even when an exception has been set).  The function is thread-specific, but
+   there is no way for the profiler to know about context switches between threads,
+   so it does not make sense to use this in the presence of multiple threads. Also,
+   its return value is not used, so it can simply return ``None``.
+
+
+.. function:: setrecursionlimit(limit)
+
+   Set the maximum depth of the Python interpreter stack to *limit*.  This limit
+   prevents infinite recursion from causing an overflow of the C stack and crashing
+   Python.
+
+   The highest possible limit is platform-dependent.  A user may need to set the
+   limit higher when she has a program that requires deep recursion and a platform
+   that supports a higher limit.  This should be done with care, because a too-high
+   limit can lead to a crash.
+
+
+.. function:: settrace(tracefunc)
+
+   .. index::
+      single: trace function
+      single: debugger
+
+   Set the system's trace function, which allows you to implement a Python
+   source code debugger in Python.  See section :ref:`debugger-hooks` in the
+   chapter on the Python debugger.  The function is thread-specific; for a
+   debugger to support multiple threads, it must be registered using
+   :func:`settrace` for each thread being debugged.
+
+   .. note::
+
+      The :func:`settrace` function is intended only for implementing debuggers,
+      profilers, coverage tools and the like. Its behavior is part of the
+      implementation platform, rather than part of the language definition, and thus
+      may not be available in all Python implementations.
+
+
+.. function:: settscdump(on_flag)
+
+   Activate dumping of VM measurements using the Pentium timestamp counter, if
+   *on_flag* is true. Deactivate these dumps if *on_flag* is off. The function is
+   available only if Python was compiled with :option:`--with-tsc`. To understand
+   the output of this dump, read :file:`Python/ceval.c` in the Python sources.
+
+   .. versionadded:: 2.4
+
+
+.. data:: stdin
+          stdout
+          stderr
+
+   File objects corresponding to the interpreter's standard input, output and error
+   streams.  ``stdin`` is used for all interpreter input except for scripts.
+   ``stdout`` is used for the output of :keyword:`print` and expression statements.
+   The interpreter's own prompts and (almost all of) its error messages go to
+   ``stderr``.  ``stdout`` and ``stderr`` needn't be built-in file objects: any
+   object is acceptable as long as it has a :meth:`write` method that takes a
+   string argument.  (Changing these objects doesn't affect the standard I/O
+   streams of processes executed by :func:`os.popen`, :func:`os.system` or the
+   :func:`exec\*` family of functions in the :mod:`os` module.)
+
+
+.. data:: __stdin__
+          __stdout__
+          __stderr__
+
+   These objects contain the original values of ``stdin``, ``stderr`` and
+   ``stdout`` at the start of the program.  They are used during finalization, and
+   could be useful to restore the actual files to known working file objects in
+   case they have been overwritten with a broken object.
+
+
+.. data:: tracebacklimit
+
+   When this variable is set to an integer value, it determines the maximum number
+   of levels of traceback information printed when an unhandled exception occurs.
+   The default is ``1000``.  When set to ``0`` or less, all traceback information
+   is suppressed and only the exception type and value are printed.
+
+
+.. data:: version
+
+   A string containing the version number of the Python interpreter plus additional
+   information on the build number and compiler used. It has a value of the form
+   ``'version (#build_number, build_date, build_time) [compiler]'``.  The first
+   three characters are used to identify the version in the installation
+   directories (where appropriate on each platform).  An example::
+
+      >>> import sys
+      >>> sys.version
+      '1.5.2 (#0 Apr 13 1999, 10:51:12) [MSC 32 bit (Intel)]'
+
+
+.. data:: api_version
+
+   The C API version for this interpreter.  Programmers may find this useful when
+   debugging version conflicts between Python and extension modules.
+
+   .. versionadded:: 2.3
+
+
+.. data:: version_info
+
+   A tuple containing the five components of the version number: *major*, *minor*,
+   *micro*, *releaselevel*, and *serial*.  All values except *releaselevel* are
+   integers; the release level is ``'alpha'``, ``'beta'``, ``'candidate'``, or
+   ``'final'``.  The ``version_info`` value corresponding to the Python version 2.0
+   is ``(2, 0, 0, 'final', 0)``.
+
+   .. versionadded:: 2.0
+
+
+.. data:: warnoptions
+
+   This is an implementation detail of the warnings framework; do not modify this
+   value.  Refer to the :mod:`warnings` module for more information on the warnings
+   framework.
+
+
+.. data:: winver
+
+   The version number used to form registry keys on Windows platforms. This is
+   stored as string resource 1000 in the Python DLL.  The value is normally the
+   first three characters of :const:`version`.  It is provided in the :mod:`sys`
+   module for informational purposes; modifying this value has no effect on the
+   registry keys used by Python. Availability: Windows.
+
+
+.. seealso::
+
+   Module :mod:`site`
+      This describes how to use .pth files to extend ``sys.path``.
+
diff --git a/Doc/library/syslog.rst b/Doc/library/syslog.rst
new file mode 100644
index 0000000..549f26b
--- /dev/null
+++ b/Doc/library/syslog.rst
@@ -0,0 +1,66 @@
+
+:mod:`syslog` --- Unix syslog library routines
+==============================================
+
+.. module:: syslog
+   :platform: Unix
+   :synopsis: An interface to the Unix syslog library routines.
+
+
+This module provides an interface to the Unix ``syslog`` library routines.
+Refer to the Unix manual pages for a detailed description of the ``syslog``
+facility.
+
+The module defines the following functions:
+
+
+.. function:: syslog([priority,] message)
+
+   Send the string *message* to the system logger.  A trailing newline is added if
+   necessary.  Each message is tagged with a priority composed of a *facility* and
+   a *level*.  The optional *priority* argument, which defaults to
+   :const:`LOG_INFO`, determines the message priority.  If the facility is not
+   encoded in *priority* using logical-or (``LOG_INFO | LOG_USER``), the value
+   given in the :func:`openlog` call is used.
+
+
+.. function:: openlog(ident[, logopt[, facility]])
+
+   Logging options other than the defaults can be set by explicitly opening the log
+   file with :func:`openlog` prior to calling :func:`syslog`.  The defaults are
+   (usually) *ident* = ``'syslog'``, *logopt* = ``0``, *facility* =
+   :const:`LOG_USER`.  The *ident* argument is a string which is prepended to every
+   message.  The optional *logopt* argument is a bit field - see below for possible
+   values to combine.  The optional *facility* argument sets the default facility
+   for messages which do not have a facility explicitly encoded.
+
+
+.. function:: closelog()
+
+   Close the log file.
+
+
+.. function:: setlogmask(maskpri)
+
+   Set the priority mask to *maskpri* and return the previous mask value.  Calls to
+   :func:`syslog` with a priority level not set in *maskpri* are ignored.  The
+   default is to log all priorities.  The function ``LOG_MASK(pri)`` calculates the
+   mask for the individual priority *pri*.  The function ``LOG_UPTO(pri)``
+   calculates the mask for all priorities up to and including *pri*.
+
+The module defines the following constants:
+
+Priority levels (high to low):
+   :const:`LOG_EMERG`, :const:`LOG_ALERT`, :const:`LOG_CRIT`, :const:`LOG_ERR`,
+   :const:`LOG_WARNING`, :const:`LOG_NOTICE`, :const:`LOG_INFO`,
+   :const:`LOG_DEBUG`.
+
+Facilities:
+   :const:`LOG_KERN`, :const:`LOG_USER`, :const:`LOG_MAIL`, :const:`LOG_DAEMON`,
+   :const:`LOG_AUTH`, :const:`LOG_LPR`, :const:`LOG_NEWS`, :const:`LOG_UUCP`,
+   :const:`LOG_CRON` and :const:`LOG_LOCAL0` to :const:`LOG_LOCAL7`.
+
+Log options:
+   :const:`LOG_PID`, :const:`LOG_CONS`, :const:`LOG_NDELAY`, :const:`LOG_NOWAIT`
+   and :const:`LOG_PERROR` if defined in ``<syslog.h>``.
+
diff --git a/Doc/library/tabnanny.rst b/Doc/library/tabnanny.rst
new file mode 100644
index 0000000..8032655
--- /dev/null
+++ b/Doc/library/tabnanny.rst
@@ -0,0 +1,70 @@
+
+:mod:`tabnanny` --- Detection of ambiguous indentation
+======================================================
+
+.. module:: tabnanny
+   :synopsis: Tool for detecting white space related problems in Python source files in a
+              directory tree.
+.. moduleauthor:: Tim Peters <tim_one@users.sourceforge.net>
+.. sectionauthor:: Peter Funk <pf@artcom-gmbh.de>
+
+
+.. % rudimentary documentation based on module comments, by Peter Funk
+.. % <pf@artcom-gmbh.de>
+
+For the time being this module is intended to be called as a script. However it
+is possible to import it into an IDE and use the function :func:`check`
+described below.
+
+.. warning::
+
+   The API provided by this module is likely to change  in future releases; such
+   changes may not be backward compatible.
+
+
+.. function:: check(file_or_dir)
+
+   If *file_or_dir* is a directory and not a symbolic link, then recursively
+   descend the directory tree named by *file_or_dir*, checking all :file:`.py`
+   files along the way.  If *file_or_dir* is an ordinary Python source file, it is
+   checked for whitespace related problems.  The diagnostic messages are written to
+   standard output using the print statement.
+
+
+.. data:: verbose
+
+   Flag indicating whether to print verbose messages. This is incremented by the
+   ``-v`` option if called as a script.
+
+
+.. data:: filename_only
+
+   Flag indicating whether to print only the filenames of files containing
+   whitespace related problems.  This is set to true by the ``-q`` option if called
+   as a script.
+
+
+.. exception:: NannyNag
+
+   Raised by :func:`tokeneater` if detecting an ambiguous indent. Captured and
+   handled in :func:`check`.
+
+
+.. function:: tokeneater(type, token, start, end, line)
+
+   This function is used by :func:`check` as a callback parameter to the function
+   :func:`tokenize.tokenize`.
+
+.. % XXX FIXME: Document \function{errprint},
+.. % \function{format_witnesses} \class{Whitespace}
+.. % check_equal, indents
+.. % \function{reset_globals}
+
+
+.. seealso::
+
+   Module :mod:`tokenize`
+      Lexical scanner for Python source code.
+
+   .. % XXX may be add a reference to IDLE?
+
diff --git a/Doc/library/tarfile.rst b/Doc/library/tarfile.rst
new file mode 100644
index 0000000..a0cd673
--- /dev/null
+++ b/Doc/library/tarfile.rst
@@ -0,0 +1,738 @@
+.. _tarfile-mod:
+
+:mod:`tarfile` --- Read and write tar archive files
+===================================================
+
+.. module:: tarfile
+   :synopsis: Read and write tar-format archive files.
+
+
+.. versionadded:: 2.3
+
+.. moduleauthor:: Lars Gustäbel <lars@gustaebel.de>
+.. sectionauthor:: Lars Gustäbel <lars@gustaebel.de>
+
+
+The :mod:`tarfile` module makes it possible to read and create tar archives.
+Some facts and figures:
+
+* reads and writes :mod:`gzip` and :mod:`bzip2` compressed archives.
+
+* read/write support for the POSIX.1-1988 (ustar) format.
+
+* read/write support for the GNU tar format including *longname* and *longlink*
+  extensions, read-only support for the *sparse* extension.
+
+* read/write support for the POSIX.1-2001 (pax) format.
+
+  .. versionadded:: 2.6
+
+* handles directories, regular files, hardlinks, symbolic links, fifos,
+  character devices and block devices and is able to acquire and restore file
+  information like timestamp, access permissions and owner.
+
+* can handle tape devices.
+
+
+.. function:: open(name[, mode[, fileobj[, bufsize]]], **kwargs)
+
+   Return a :class:`TarFile` object for the pathname *name*. For detailed
+   information on :class:`TarFile` objects and the keyword arguments that are
+   allowed, see :ref:`tarfile-objects`.
+
+   *mode* has to be a string of the form ``'filemode[:compression]'``, it defaults
+   to ``'r'``. Here is a full list of mode combinations:
+
+   +------------------+---------------------------------------------+
+   | mode             | action                                      |
+   +==================+=============================================+
+   | ``'r' or 'r:*'`` | Open for reading with transparent           |
+   |                  | compression (recommended).                  |
+   +------------------+---------------------------------------------+
+   | ``'r:'``         | Open for reading exclusively without        |
+   |                  | compression.                                |
+   +------------------+---------------------------------------------+
+   | ``'r:gz'``       | Open for reading with gzip compression.     |
+   +------------------+---------------------------------------------+
+   | ``'r:bz2'``      | Open for reading with bzip2 compression.    |
+   +------------------+---------------------------------------------+
+   | ``'a' or 'a:'``  | Open for appending with no compression. The |
+   |                  | file is created if it does not exist.       |
+   +------------------+---------------------------------------------+
+   | ``'w' or 'w:'``  | Open for uncompressed writing.              |
+   +------------------+---------------------------------------------+
+   | ``'w:gz'``       | Open for gzip compressed writing.           |
+   +------------------+---------------------------------------------+
+   | ``'w:bz2'``      | Open for bzip2 compressed writing.          |
+   +------------------+---------------------------------------------+
+
+   Note that ``'a:gz'`` or ``'a:bz2'`` is not possible. If *mode* is not suitable
+   to open a certain (compressed) file for reading, :exc:`ReadError` is raised. Use
+   *mode* ``'r'`` to avoid this.  If a compression method is not supported,
+   :exc:`CompressionError` is raised.
+
+   If *fileobj* is specified, it is used as an alternative to a file object opened
+   for *name*. It is supposed to be at position 0.
+
+   For special purposes, there is a second format for *mode*:
+   ``'filemode|[compression]'``.  :func:`open` will return a :class:`TarFile`
+   object that processes its data as a stream of blocks.  No random seeking will
+   be done on the file. If given, *fileobj* may be any object that has a
+   :meth:`read` or :meth:`write` method (depending on the *mode*). *bufsize*
+   specifies the blocksize and defaults to ``20 * 512`` bytes. Use this variant
+   in combination with e.g. ``sys.stdin``, a socket file object or a tape
+   device. However, such a :class:`TarFile` object is limited in that it does
+   not allow to be accessed randomly, see :ref:`tar-examples`.  The currently
+   possible modes:
+
+   +-------------+--------------------------------------------+
+   | Mode        | Action                                     |
+   +=============+============================================+
+   | ``'r|*'``   | Open a *stream* of tar blocks for reading  |
+   |             | with transparent compression.              |
+   +-------------+--------------------------------------------+
+   | ``'r|'``    | Open a *stream* of uncompressed tar blocks |
+   |             | for reading.                               |
+   +-------------+--------------------------------------------+
+   | ``'r|gz'``  | Open a gzip compressed *stream* for        |
+   |             | reading.                                   |
+   +-------------+--------------------------------------------+
+   | ``'r|bz2'`` | Open a bzip2 compressed *stream* for       |
+   |             | reading.                                   |
+   +-------------+--------------------------------------------+
+   | ``'w|'``    | Open an uncompressed *stream* for writing. |
+   +-------------+--------------------------------------------+
+   | ``'w|gz'``  | Open an gzip compressed *stream* for       |
+   |             | writing.                                   |
+   +-------------+--------------------------------------------+
+   | ``'w|bz2'`` | Open an bzip2 compressed *stream* for      |
+   |             | writing.                                   |
+   +-------------+--------------------------------------------+
+
+
+.. class:: TarFile
+
+   Class for reading and writing tar archives. Do not use this class directly,
+   better use :func:`open` instead. See :ref:`tarfile-objects`.
+
+
+.. function:: is_tarfile(name)
+
+   Return :const:`True` if *name* is a tar archive file, that the :mod:`tarfile`
+   module can read.
+
+
+.. class:: TarFileCompat(filename[, mode[, compression]])
+
+   Class for limited access to tar archives with a :mod:`zipfile`\ -like interface.
+   Please consult the documentation of the :mod:`zipfile` module for more details.
+   *compression* must be one of the following constants:
+
+
+   .. data:: TAR_PLAIN
+
+      Constant for an uncompressed tar archive.
+
+
+   .. data:: TAR_GZIPPED
+
+      Constant for a :mod:`gzip` compressed tar archive.
+
+
+.. exception:: TarError
+
+   Base class for all :mod:`tarfile` exceptions.
+
+
+.. exception:: ReadError
+
+   Is raised when a tar archive is opened, that either cannot be handled by the
+   :mod:`tarfile` module or is somehow invalid.
+
+
+.. exception:: CompressionError
+
+   Is raised when a compression method is not supported or when the data cannot be
+   decoded properly.
+
+
+.. exception:: StreamError
+
+   Is raised for the limitations that are typical for stream-like :class:`TarFile`
+   objects.
+
+
+.. exception:: ExtractError
+
+   Is raised for *non-fatal* errors when using :meth:`extract`, but only if
+   :attr:`TarFile.errorlevel`\ ``== 2``.
+
+
+.. exception:: HeaderError
+
+   Is raised by :meth:`frombuf` if the buffer it gets is invalid.
+
+   .. versionadded:: 2.6
+
+Each of the following constants defines a tar archive format that the
+:mod:`tarfile` module is able to create. See section :ref:`tar-formats` for
+details.
+
+
+.. data:: USTAR_FORMAT
+
+   POSIX.1-1988 (ustar) format.
+
+
+.. data:: GNU_FORMAT
+
+   GNU tar format.
+
+
+.. data:: PAX_FORMAT
+
+   POSIX.1-2001 (pax) format.
+
+
+.. data:: DEFAULT_FORMAT
+
+   The default format for creating archives. This is currently :const:`GNU_FORMAT`.
+
+
+.. seealso::
+
+   Module :mod:`zipfile`
+      Documentation of the :mod:`zipfile` standard module.
+
+   `GNU tar manual, Basic Tar Format <http://www.gnu.org/software/tar/manual/html_node/tar_134.html#SEC134>`_
+      Documentation for tar archive files, including GNU tar extensions.
+
+.. % -----------------
+.. % TarFile Objects
+.. % -----------------
+
+
+.. _tarfile-objects:
+
+TarFile Objects
+---------------
+
+The :class:`TarFile` object provides an interface to a tar archive. A tar
+archive is a sequence of blocks. An archive member (a stored file) is made up of
+a header block followed by data blocks. It is possible to store a file in a tar
+archive several times. Each archive member is represented by a :class:`TarInfo`
+object, see :ref:`tarinfo-objects` for details.
+
+
+.. class:: TarFile(name=None, mode='r', fileobj=None, format=DEFAULT_FORMAT, tarinfo=TarInfo, dereference=False, ignore_zeros=False, encoding=None, errors=None, pax_headers=None, debug=0, errorlevel=0)
+
+   All following arguments are optional and can be accessed as instance attributes
+   as well.
+
+   *name* is the pathname of the archive. It can be omitted if *fileobj* is given.
+   In this case, the file object's :attr:`name` attribute is used if it exists.
+
+   *mode* is either ``'r'`` to read from an existing archive, ``'a'`` to append
+   data to an existing file or ``'w'`` to create a new file overwriting an existing
+   one.
+
+   If *fileobj* is given, it is used for reading or writing data. If it can be
+   determined, *mode* is overridden by *fileobj*'s mode. *fileobj* will be used
+   from position 0.
+
+   .. note::
+
+      *fileobj* is not closed, when :class:`TarFile` is closed.
+
+   *format* controls the archive format. It must be one of the constants
+   :const:`USTAR_FORMAT`, :const:`GNU_FORMAT` or :const:`PAX_FORMAT` that are
+   defined at module level.
+
+   .. versionadded:: 2.6
+
+   The *tarinfo* argument can be used to replace the default :class:`TarInfo` class
+   with a different one.
+
+   .. versionadded:: 2.6
+
+   If *dereference* is ``False``, add symbolic and hard links to the archive. If it
+   is ``True``, add the content of the target files to the archive. This has no
+   effect on systems that do not support symbolic links.
+
+   If *ignore_zeros* is ``False``, treat an empty block as the end of the archive.
+   If it is *True*, skip empty (and invalid) blocks and try to get as many members
+   as possible. This is only useful for reading concatenated or damaged archives.
+
+   *debug* can be set from ``0`` (no debug messages) up to ``3`` (all debug
+   messages). The messages are written to ``sys.stderr``.
+
+   If *errorlevel* is ``0``, all errors are ignored when using :meth:`extract`.
+   Nevertheless, they appear as error messages in the debug output, when debugging
+   is enabled.  If ``1``, all *fatal* errors are raised as :exc:`OSError` or
+   :exc:`IOError` exceptions. If ``2``, all *non-fatal* errors are raised as
+   :exc:`TarError` exceptions as well.
+
+   The *encoding* and *errors* arguments control the way strings are converted to
+   unicode objects and vice versa. The default settings will work for most users.
+   See section :ref:`tar-unicode` for in-depth information.
+
+   .. versionadded:: 2.6
+
+   The *pax_headers* argument is an optional dictionary of unicode strings which
+   will be added as a pax global header if *format* is :const:`PAX_FORMAT`.
+
+   .. versionadded:: 2.6
+
+
+.. method:: TarFile.open(...)
+
+   Alternative constructor. The :func:`open` function on module level is actually a
+   shortcut to this classmethod. See section :ref:`tarfile-mod` for details.
+
+
+.. method:: TarFile.getmember(name)
+
+   Return a :class:`TarInfo` object for member *name*. If *name* can not be found
+   in the archive, :exc:`KeyError` is raised.
+
+   .. note::
+
+      If a member occurs more than once in the archive, its last occurrence is assumed
+      to be the most up-to-date version.
+
+
+.. method:: TarFile.getmembers()
+
+   Return the members of the archive as a list of :class:`TarInfo` objects. The
+   list has the same order as the members in the archive.
+
+
+.. method:: TarFile.getnames()
+
+   Return the members as a list of their names. It has the same order as the list
+   returned by :meth:`getmembers`.
+
+
+.. method:: TarFile.list(verbose=True)
+
+   Print a table of contents to ``sys.stdout``. If *verbose* is :const:`False`,
+   only the names of the members are printed. If it is :const:`True`, output
+   similar to that of :program:`ls -l` is produced.
+
+
+.. method:: TarFile.next()
+
+   Return the next member of the archive as a :class:`TarInfo` object, when
+   :class:`TarFile` is opened for reading. Return ``None`` if there is no more
+   available.
+
+
+.. method:: TarFile.extractall([path[, members]])
+
+   Extract all members from the archive to the current working directory or
+   directory *path*. If optional *members* is given, it must be a subset of the
+   list returned by :meth:`getmembers`. Directory information like owner,
+   modification time and permissions are set after all members have been extracted.
+   This is done to work around two problems: A directory's modification time is
+   reset each time a file is created in it. And, if a directory's permissions do
+   not allow writing, extracting files to it will fail.
+
+   .. versionadded:: 2.5
+
+
+.. method:: TarFile.extract(member[, path])
+
+   Extract a member from the archive to the current working directory, using its
+   full name. Its file information is extracted as accurately as possible. *member*
+   may be a filename or a :class:`TarInfo` object. You can specify a different
+   directory using *path*.
+
+   .. note::
+
+      Because the :meth:`extract` method allows random access to a tar archive there
+      are some issues you must take care of yourself. See the description for
+      :meth:`extractall` above.
+
+
+.. method:: TarFile.extractfile(member)
+
+   Extract a member from the archive as a file object. *member* may be a filename
+   or a :class:`TarInfo` object. If *member* is a regular file, a file-like object
+   is returned. If *member* is a link, a file-like object is constructed from the
+   link's target. If *member* is none of the above, ``None`` is returned.
+
+   .. note::
+
+      The file-like object is read-only and provides the following methods:
+      :meth:`read`, :meth:`readline`, :meth:`readlines`, :meth:`seek`, :meth:`tell`.
+
+
+.. method:: TarFile.add(name[, arcname[, recursive[, exclude]]])
+
+   Add the file *name* to the archive. *name* may be any type of file (directory,
+   fifo, symbolic link, etc.). If given, *arcname* specifies an alternative name
+   for the file in the archive. Directories are added recursively by default. This
+   can be avoided by setting *recursive* to :const:`False`. If *exclude* is given
+   it must be a function that takes one filename argument and returns a boolean
+   value. Depending on this value the respective file is either excluded
+   (:const:`True`) or added (:const:`False`).
+
+   .. versionchanged:: 2.6
+      Added the *exclude* parameter.
+
+
+.. method:: TarFile.addfile(tarinfo[, fileobj])
+
+   Add the :class:`TarInfo` object *tarinfo* to the archive. If *fileobj* is given,
+   ``tarinfo.size`` bytes are read from it and added to the archive.  You can
+   create :class:`TarInfo` objects using :meth:`gettarinfo`.
+
+   .. note::
+
+      On Windows platforms, *fileobj* should always be opened with mode ``'rb'`` to
+      avoid irritation about the file size.
+
+
+.. method:: TarFile.gettarinfo([name[, arcname[, fileobj]]])
+
+   Create a :class:`TarInfo` object for either the file *name* or the file object
+   *fileobj* (using :func:`os.fstat` on its file descriptor).  You can modify some
+   of the :class:`TarInfo`'s attributes before you add it using :meth:`addfile`.
+   If given, *arcname* specifies an alternative name for the file in the archive.
+
+
+.. method:: TarFile.close()
+
+   Close the :class:`TarFile`. In write mode, two finishing zero blocks are
+   appended to the archive.
+
+
+.. attribute:: TarFile.posix
+
+   Setting this to :const:`True` is equivalent to setting the :attr:`format`
+   attribute to :const:`USTAR_FORMAT`, :const:`False` is equivalent to
+   :const:`GNU_FORMAT`.
+
+   .. versionchanged:: 2.4
+      *posix* defaults to :const:`False`.
+
+   .. deprecated:: 2.6
+      Use the :attr:`format` attribute instead.
+
+
+.. attribute:: TarFile.pax_headers
+
+   A dictionary containing key-value pairs of pax global headers.
+
+   .. versionadded:: 2.6
+
+.. % -----------------
+.. % TarInfo Objects
+.. % -----------------
+
+
+.. _tarinfo-objects:
+
+TarInfo Objects
+---------------
+
+A :class:`TarInfo` object represents one member in a :class:`TarFile`. Aside
+from storing all required attributes of a file (like file type, size, time,
+permissions, owner etc.), it provides some useful methods to determine its type.
+It does *not* contain the file's data itself.
+
+:class:`TarInfo` objects are returned by :class:`TarFile`'s methods
+:meth:`getmember`, :meth:`getmembers` and :meth:`gettarinfo`.
+
+
+.. class:: TarInfo([name])
+
+   Create a :class:`TarInfo` object.
+
+
+.. method:: TarInfo.frombuf(buf)
+
+   Create and return a :class:`TarInfo` object from string buffer *buf*.
+
+   .. versionadded:: 2.6
+      Raises :exc:`HeaderError` if the buffer is invalid..
+
+
+.. method:: TarInfo.fromtarfile(tarfile)
+
+   Read the next member from the :class:`TarFile` object *tarfile* and return it as
+   a :class:`TarInfo` object.
+
+   .. versionadded:: 2.6
+
+
+.. method:: TarInfo.tobuf([format[, encoding [, errors]]])
+
+   Create a string buffer from a :class:`TarInfo` object. For information on the
+   arguments see the constructor of the :class:`TarFile` class.
+
+   .. versionchanged:: 2.6
+      The arguments were added.
+
+A ``TarInfo`` object has the following public data attributes:
+
+
+.. attribute:: TarInfo.name
+
+   Name of the archive member.
+
+
+.. attribute:: TarInfo.size
+
+   Size in bytes.
+
+
+.. attribute:: TarInfo.mtime
+
+   Time of last modification.
+
+
+.. attribute:: TarInfo.mode
+
+   Permission bits.
+
+
+.. attribute:: TarInfo.type
+
+   File type.  *type* is usually one of these constants: :const:`REGTYPE`,
+   :const:`AREGTYPE`, :const:`LNKTYPE`, :const:`SYMTYPE`, :const:`DIRTYPE`,
+   :const:`FIFOTYPE`, :const:`CONTTYPE`, :const:`CHRTYPE`, :const:`BLKTYPE`,
+   :const:`GNUTYPE_SPARSE`.  To determine the type of a :class:`TarInfo` object
+   more conveniently, use the ``is_*()`` methods below.
+
+
+.. attribute:: TarInfo.linkname
+
+   Name of the target file name, which is only present in :class:`TarInfo` objects
+   of type :const:`LNKTYPE` and :const:`SYMTYPE`.
+
+
+.. attribute:: TarInfo.uid
+
+   User ID of the user who originally stored this member.
+
+
+.. attribute:: TarInfo.gid
+
+   Group ID of the user who originally stored this member.
+
+
+.. attribute:: TarInfo.uname
+
+   User name.
+
+
+.. attribute:: TarInfo.gname
+
+   Group name.
+
+
+.. attribute:: TarInfo.pax_headers
+
+   A dictionary containing key-value pairs of an associated pax extended header.
+
+   .. versionadded:: 2.6
+
+A :class:`TarInfo` object also provides some convenient query methods:
+
+
+.. method:: TarInfo.isfile()
+
+   Return :const:`True` if the :class:`Tarinfo` object is a regular file.
+
+
+.. method:: TarInfo.isreg()
+
+   Same as :meth:`isfile`.
+
+
+.. method:: TarInfo.isdir()
+
+   Return :const:`True` if it is a directory.
+
+
+.. method:: TarInfo.issym()
+
+   Return :const:`True` if it is a symbolic link.
+
+
+.. method:: TarInfo.islnk()
+
+   Return :const:`True` if it is a hard link.
+
+
+.. method:: TarInfo.ischr()
+
+   Return :const:`True` if it is a character device.
+
+
+.. method:: TarInfo.isblk()
+
+   Return :const:`True` if it is a block device.
+
+
+.. method:: TarInfo.isfifo()
+
+   Return :const:`True` if it is a FIFO.
+
+
+.. method:: TarInfo.isdev()
+
+   Return :const:`True` if it is one of character device, block device or FIFO.
+
+.. % ------------------------
+.. % Examples
+.. % ------------------------
+
+
+.. _tar-examples:
+
+Examples
+--------
+
+How to extract an entire tar archive to the current working directory::
+
+   import tarfile
+   tar = tarfile.open("sample.tar.gz")
+   tar.extractall()
+   tar.close()
+
+How to create an uncompressed tar archive from a list of filenames::
+
+   import tarfile
+   tar = tarfile.open("sample.tar", "w")
+   for name in ["foo", "bar", "quux"]:
+       tar.add(name)
+   tar.close()
+
+How to read a gzip compressed tar archive and display some member information::
+
+   import tarfile
+   tar = tarfile.open("sample.tar.gz", "r:gz")
+   for tarinfo in tar:
+       print tarinfo.name, "is", tarinfo.size, "bytes in size and is",
+       if tarinfo.isreg():
+           print "a regular file."
+       elif tarinfo.isdir():
+           print "a directory."
+       else:
+           print "something else."
+   tar.close()
+
+How to create a tar archive with faked information::
+
+   import tarfile
+   tar = tarfile.open("sample.tar.gz", "w:gz")
+   for name in namelist:
+       tarinfo = tar.gettarinfo(name, "fakeproj-1.0/" + name)
+       tarinfo.uid = 123
+       tarinfo.gid = 456
+       tarinfo.uname = "johndoe"
+       tarinfo.gname = "fake"
+       tar.addfile(tarinfo, file(name))
+   tar.close()
+
+The *only* way to extract an uncompressed tar stream from ``sys.stdin``::
+
+   import sys
+   import tarfile
+   tar = tarfile.open(mode="r|", fileobj=sys.stdin)
+   for tarinfo in tar:
+       tar.extract(tarinfo)
+   tar.close()
+
+.. % ------------
+.. % Tar format
+.. % ------------
+
+
+.. _tar-formats:
+
+Supported tar formats
+---------------------
+
+There are three tar formats that can be created with the :mod:`tarfile` module:
+
+* The POSIX.1-1988 ustar format (:const:`USTAR_FORMAT`). It supports filenames
+  up to a length of at best 256 characters and linknames up to 100 characters. The
+  maximum file size is 8 gigabytes. This is an old and limited but widely
+  supported format.
+
+* The GNU tar format (:const:`GNU_FORMAT`). It supports long filenames and
+  linknames, files bigger than 8 gigabytes and sparse files. It is the de facto
+  standard on GNU/Linux systems. :mod:`tarfile` fully supports the GNU tar
+  extensions for long names, sparse file support is read-only.
+
+* The POSIX.1-2001 pax format (:const:`PAX_FORMAT`). It is the most flexible
+  format with virtually no limits. It supports long filenames and linknames, large
+  files and stores pathnames in a portable way. However, not all tar
+  implementations today are able to handle pax archives properly.
+
+  The *pax* format is an extension to the existing *ustar* format. It uses extra
+  headers for information that cannot be stored otherwise. There are two flavours
+  of pax headers: Extended headers only affect the subsequent file header, global
+  headers are valid for the complete archive and affect all following files. All
+  the data in a pax header is encoded in *UTF-8* for portability reasons.
+
+There are some more variants of the tar format which can be read, but not
+created:
+
+* The ancient V7 format. This is the first tar format from Unix Seventh Edition,
+  storing only regular files and directories. Names must not be longer than 100
+  characters, there is no user/group name information. Some archives have
+  miscalculated header checksums in case of fields with non-ASCII characters.
+
+* The SunOS tar extended format. This format is a variant of the POSIX.1-2001
+  pax format, but is not compatible.
+
+.. % ----------------
+.. % Unicode issues
+.. % ----------------
+
+
+.. _tar-unicode:
+
+Unicode issues
+--------------
+
+The tar format was originally conceived to make backups on tape drives with the
+main focus on preserving file system information. Nowadays tar archives are
+commonly used for file distribution and exchanging archives over networks. One
+problem of the original format (that all other formats are merely variants of)
+is that there is no concept of supporting different character encodings. For
+example, an ordinary tar archive created on a *UTF-8* system cannot be read
+correctly on a *Latin-1* system if it contains non-ASCII characters. Names (i.e.
+filenames, linknames, user/group names) containing these characters will appear
+damaged.  Unfortunately, there is no way to autodetect the encoding of an
+archive.
+
+The pax format was designed to solve this problem. It stores non-ASCII names
+using the universal character encoding *UTF-8*. When a pax archive is read,
+these *UTF-8* names are converted to the encoding of the local file system.
+
+The details of unicode conversion are controlled by the *encoding* and *errors*
+keyword arguments of the :class:`TarFile` class.
+
+The default value for *encoding* is the local character encoding. It is deduced
+from :func:`sys.getfilesystemencoding` and :func:`sys.getdefaultencoding`. In
+read mode, *encoding* is used exclusively to convert unicode names from a pax
+archive to strings in the local character encoding. In write mode, the use of
+*encoding* depends on the chosen archive format. In case of :const:`PAX_FORMAT`,
+input names that contain non-ASCII characters need to be decoded before being
+stored as *UTF-8* strings. The other formats do not make use of *encoding*
+unless unicode objects are used as input names. These are converted to 8-bit
+character strings before they are added to the archive.
+
+The *errors* argument defines how characters are treated that cannot be
+converted to or from *encoding*. Possible values are listed in section
+:ref:`codec-base-classes`. In read mode, there is an additional scheme
+``'utf-8'`` which means that bad characters are replaced by their *UTF-8*
+representation. This is the default scheme. In write mode the default value for
+*errors* is ``'strict'`` to ensure that name information is not altered
+unnoticed.
+
diff --git a/Doc/library/telnetlib.rst b/Doc/library/telnetlib.rst
new file mode 100644
index 0000000..f6ab852
--- /dev/null
+++ b/Doc/library/telnetlib.rst
@@ -0,0 +1,246 @@
+
+:mod:`telnetlib` --- Telnet client
+==================================
+
+.. module:: telnetlib
+   :synopsis: Telnet client class.
+.. sectionauthor:: Skip Montanaro <skip@mojam.com>
+
+
+.. index:: single: protocol; Telnet
+
+The :mod:`telnetlib` module provides a :class:`Telnet` class that implements the
+Telnet protocol.  See :rfc:`854` for details about the protocol. In addition, it
+provides symbolic constants for the protocol characters (see below), and for the
+telnet options. The symbolic names of the telnet options follow the definitions
+in ``arpa/telnet.h``, with the leading ``TELOPT_`` removed. For symbolic names
+of options which are traditionally not included in ``arpa/telnet.h``, see the
+module source itself.
+
+The symbolic constants for the telnet commands are: IAC, DONT, DO, WONT, WILL,
+SE (Subnegotiation End), NOP (No Operation), DM (Data Mark), BRK (Break), IP
+(Interrupt process), AO (Abort output), AYT (Are You There), EC (Erase
+Character), EL (Erase Line), GA (Go Ahead), SB (Subnegotiation Begin).
+
+
+.. class:: Telnet([host[, port[, timeout]]])
+
+   :class:`Telnet` represents a connection to a Telnet server. The instance is
+   initially not connected by default; the :meth:`open` method must be used to
+   establish a connection.  Alternatively, the host name and optional port number
+   can be passed to the constructor, to, in which case the connection to the server
+   will be established before the constructor returns. The optional *timeout*
+   parameter specifies a timeout in seconds for the connection attempt (if not
+   specified, or passed as None, the global default timeout setting will be used).
+
+   Do not reopen an already connected instance.
+
+   This class has many :meth:`read_\*` methods.  Note that some of them  raise
+   :exc:`EOFError` when the end of the connection is read, because they can return
+   an empty string for other reasons.  See the individual descriptions below.
+
+   .. versionchanged:: 2.6
+      *timeout* was added.
+
+
+.. seealso::
+
+   :rfc:`854` - Telnet Protocol Specification
+      Definition of the Telnet protocol.
+
+
+.. _telnet-objects:
+
+Telnet Objects
+--------------
+
+:class:`Telnet` instances have the following methods:
+
+
+.. method:: Telnet.read_until(expected[, timeout])
+
+   Read until a given string, *expected*, is encountered or until *timeout* seconds
+   have passed.
+
+   When no match is found, return whatever is available instead, possibly the empty
+   string.  Raise :exc:`EOFError` if the connection is closed and no cooked data is
+   available.
+
+
+.. method:: Telnet.read_all()
+
+   Read all data until EOF; block until connection closed.
+
+
+.. method:: Telnet.read_some()
+
+   Read at least one byte of cooked data unless EOF is hit. Return ``''`` if EOF is
+   hit.  Block if no data is immediately available.
+
+
+.. method:: Telnet.read_very_eager()
+
+   Read everything that can be without blocking in I/O (eager).
+
+   Raise :exc:`EOFError` if connection closed and no cooked data available.  Return
+   ``''`` if no cooked data available otherwise. Do not block unless in the midst
+   of an IAC sequence.
+
+
+.. method:: Telnet.read_eager()
+
+   Read readily available data.
+
+   Raise :exc:`EOFError` if connection closed and no cooked data available.  Return
+   ``''`` if no cooked data available otherwise. Do not block unless in the midst
+   of an IAC sequence.
+
+
+.. method:: Telnet.read_lazy()
+
+   Process and return data already in the queues (lazy).
+
+   Raise :exc:`EOFError` if connection closed and no data available. Return ``''``
+   if no cooked data available otherwise.  Do not block unless in the midst of an
+   IAC sequence.
+
+
+.. method:: Telnet.read_very_lazy()
+
+   Return any data available in the cooked queue (very lazy).
+
+   Raise :exc:`EOFError` if connection closed and no data available. Return ``''``
+   if no cooked data available otherwise.  This method never blocks.
+
+
+.. method:: Telnet.read_sb_data()
+
+   Return the data collected between a SB/SE pair (suboption begin/end). The
+   callback should access these data when it was invoked with a ``SE`` command.
+   This method never blocks.
+
+   .. versionadded:: 2.3
+
+
+.. method:: Telnet.open(host[, port[, timeout]])
+
+   Connect to a host. The optional second argument is the port number, which
+   defaults to the standard Telnet port (23). The optional *timeout* parameter
+   specifies a timeout in seconds for the connection attempt (if not specified, or
+   passed as None, the global default timeout setting will be used).
+
+   Do not try to reopen an already connected instance.
+
+   .. versionchanged:: 2.6
+      *timeout* was added.
+
+
+.. method:: Telnet.msg(msg[, *args])
+
+   Print a debug message when the debug level is ``>`` 0. If extra arguments are
+   present, they are substituted in the message using the standard string
+   formatting operator.
+
+
+.. method:: Telnet.set_debuglevel(debuglevel)
+
+   Set the debug level.  The higher the value of *debuglevel*, the more debug
+   output you get (on ``sys.stdout``).
+
+
+.. method:: Telnet.close()
+
+   Close the connection.
+
+
+.. method:: Telnet.get_socket()
+
+   Return the socket object used internally.
+
+
+.. method:: Telnet.fileno()
+
+   Return the file descriptor of the socket object used internally.
+
+
+.. method:: Telnet.write(buffer)
+
+   Write a string to the socket, doubling any IAC characters. This can block if the
+   connection is blocked.  May raise :exc:`socket.error` if the connection is
+   closed.
+
+
+.. method:: Telnet.interact()
+
+   Interaction function, emulates a very dumb Telnet client.
+
+
+.. method:: Telnet.mt_interact()
+
+   Multithreaded version of :meth:`interact`.
+
+
+.. method:: Telnet.expect(list[, timeout])
+
+   Read until one from a list of a regular expressions matches.
+
+   The first argument is a list of regular expressions, either compiled
+   (:class:`re.RegexObject` instances) or uncompiled (strings). The optional second
+   argument is a timeout, in seconds; the default is to block indefinitely.
+
+   Return a tuple of three items: the index in the list of the first regular
+   expression that matches; the match object returned; and the text read up till
+   and including the match.
+
+   If end of file is found and no text was read, raise :exc:`EOFError`.  Otherwise,
+   when nothing matches, return ``(-1, None, text)`` where *text* is the text
+   received so far (may be the empty string if a timeout happened).
+
+   If a regular expression ends with a greedy match (such as ``.*``) or if more
+   than one expression can match the same input, the results are indeterministic,
+   and may depend on the I/O timing.
+
+
+.. method:: Telnet.set_option_negotiation_callback(callback)
+
+   Each time a telnet option is read on the input flow, this *callback* (if set) is
+   called with the following parameters : callback(telnet socket, command
+   (DO/DONT/WILL/WONT), option).  No other action is done afterwards by telnetlib.
+
+
+.. _telnet-example:
+
+Telnet Example
+--------------
+
+.. sectionauthor:: Peter Funk <pf@artcom-gmbh.de>
+
+
+A simple example illustrating typical use::
+
+   import getpass
+   import sys
+   import telnetlib
+
+   def raw_input(prompt):
+       sys.stdout.write(prompt)
+       sys.stdout.flush()
+       return sys.stdin.readline()
+
+   HOST = "localhost"
+   user = raw_input("Enter your remote account: ")
+   password = getpass.getpass()
+
+   tn = telnetlib.Telnet(HOST)
+
+   tn.read_until("login: ")
+   tn.write(user + "\n")
+   if password:
+       tn.read_until("Password: ")
+       tn.write(password + "\n")
+
+   tn.write("ls\n")
+   tn.write("exit\n")
+
+   print tn.read_all()
+
diff --git a/Doc/library/tempfile.rst b/Doc/library/tempfile.rst
new file mode 100644
index 0000000..cafdd05
--- /dev/null
+++ b/Doc/library/tempfile.rst
@@ -0,0 +1,216 @@
+
+:mod:`tempfile` --- Generate temporary files and directories
+============================================================
+
+.. sectionauthor:: Zack Weinberg <zack@codesourcery.com>
+
+
+.. module:: tempfile
+   :synopsis: Generate temporary files and directories.
+
+
+.. index::
+   pair: temporary; file name
+   pair: temporary; file
+
+This module generates temporary files and directories.  It works on all
+supported platforms.
+
+In version 2.3 of Python, this module was overhauled for enhanced security.  It
+now provides three new functions, :func:`NamedTemporaryFile`, :func:`mkstemp`,
+and :func:`mkdtemp`, which should eliminate all remaining need to use the
+insecure :func:`mktemp` function.  Temporary file names created by this module
+no longer contain the process ID; instead a string of six random characters is
+used.
+
+Also, all the user-callable functions now take additional arguments which allow
+direct control over the location and name of temporary files.  It is no longer
+necessary to use the global *tempdir* and *template* variables.  To maintain
+backward compatibility, the argument order is somewhat odd; it is recommended to
+use keyword arguments for clarity.
+
+The module defines the following user-callable functions:
+
+
+.. function:: TemporaryFile([mode='w+b'[, bufsize=-1[, suffix[, prefix[, dir]]]]])
+
+   Return a file (or file-like) object that can be used as a temporary storage
+   area.  The file is created using :func:`mkstemp`. It will be destroyed as soon
+   as it is closed (including an implicit close when the object is garbage
+   collected).  Under Unix, the directory entry for the file is removed immediately
+   after the file is created.  Other platforms do not support this; your code
+   should not rely on a temporary file created using this function having or not
+   having a visible name in the file system.
+
+   The *mode* parameter defaults to ``'w+b'`` so that the file created can be read
+   and written without being closed.  Binary mode is used so that it behaves
+   consistently on all platforms without regard for the data that is stored.
+   *bufsize* defaults to ``-1``, meaning that the operating system default is used.
+
+   The *dir*, *prefix* and *suffix* parameters are passed to :func:`mkstemp`.
+
+
+.. function:: NamedTemporaryFile([mode='w+b'[, bufsize=-1[, suffix[, prefix[, dir[, delete]]]]]])
+
+   This function operates exactly as :func:`TemporaryFile` does, except that the
+   file is guaranteed to have a visible name in the file system (on Unix, the
+   directory entry is not unlinked).  That name can be retrieved from the
+   :attr:`name` member of the file object.  Whether the name can be used to open
+   the file a second time, while the named temporary file is still open, varies
+   across platforms (it can be so used on Unix; it cannot on Windows NT or later).
+   If *delete* is true (the default), the file is deleted as soon as it is closed.
+
+   .. versionadded:: 2.3
+
+   .. versionadded:: 2.6
+      The *delete* parameter.
+
+
+.. function:: SpooledTemporaryFile([max_size=0, [mode='w+b'[, bufsize=-1[, suffix[, prefix[, dir]]]]]])
+
+   This function operates exactly as :func:`TemporaryFile` does, except that data
+   is spooled in memory until the file size exceeds *max_size*, or until the file's
+   :func:`fileno` method is called, at which point the contents are written to disk
+   and operation proceeds as with :func:`TemporaryFile`.
+
+   The resulting file has one additional method, :func:`rollover`, which causes the
+   file to roll over to an on-disk file regardless of its size.
+
+   .. versionadded:: 2.6
+
+
+.. function:: mkstemp([suffix[, prefix[, dir[, text]]]])
+
+   Creates a temporary file in the most secure manner possible.  There are no
+   race conditions in the file's creation, assuming that the platform properly
+   implements the :const:`os.O_EXCL` flag for :func:`os.open`.  The file is
+   readable and writable only by the creating user ID.  If the platform uses
+   permission bits to indicate whether a file is executable, the file is
+   executable by no one.  The file descriptor is not inherited by child
+   processes.
+
+   Unlike :func:`TemporaryFile`, the user of :func:`mkstemp` is responsible for
+   deleting the temporary file when done with it.
+
+   If *suffix* is specified, the file name will end with that suffix, otherwise
+   there will be no suffix.  :func:`mkstemp` does not put a dot between the file
+   name and the suffix; if you need one, put it at the beginning of *suffix*.
+
+   If *prefix* is specified, the file name will begin with that prefix; otherwise,
+   a default prefix is used.
+
+   If *dir* is specified, the file will be created in that directory; otherwise,
+   a default directory is used.  The default directory is chosen from a
+   platform-dependent list, but the user of the application can control the
+   directory location by setting the *TMPDIR*, *TEMP* or *TMP* environment
+   variables.  There is thus no guarantee that the generated filename will have
+   any nice properties, such as not requiring quoting when passed to external
+   commands via ``os.popen()``.
+
+   If *text* is specified, it indicates whether to open the file in binary mode
+   (the default) or text mode.  On some platforms, this makes no difference.
+
+   :func:`mkstemp` returns a tuple containing an OS-level handle to an open file
+   (as would be returned by :func:`os.open`) and the absolute pathname of that
+   file, in that order.
+
+   .. versionadded:: 2.3
+
+
+.. function:: mkdtemp([suffix[, prefix[, dir]]])
+
+   Creates a temporary directory in the most secure manner possible. There are no
+   race conditions in the directory's creation.  The directory is readable,
+   writable, and searchable only by the creating user ID.
+
+   The user of :func:`mkdtemp` is responsible for deleting the temporary directory
+   and its contents when done with it.
+
+   The *prefix*, *suffix*, and *dir* arguments are the same as for :func:`mkstemp`.
+
+   :func:`mkdtemp` returns the absolute pathname of the new directory.
+
+   .. versionadded:: 2.3
+
+
+.. function:: mktemp([suffix[, prefix[, dir]]])
+
+   .. deprecated:: 2.3
+      Use :func:`mkstemp` instead.
+
+   Return an absolute pathname of a file that did not exist at the time the call is
+   made.  The *prefix*, *suffix*, and *dir* arguments are the same as for
+   :func:`mkstemp`.
+
+   .. warning::
+
+      Use of this function may introduce a security hole in your program.  By the time
+      you get around to doing anything with the file name it returns, someone else may
+      have beaten you to the punch.
+
+The module uses two global variables that tell it how to construct a temporary
+name.  They are initialized at the first call to any of the functions above.
+The caller may change them, but this is discouraged; use the appropriate
+function arguments, instead.
+
+
+.. data:: tempdir
+
+   When set to a value other than ``None``, this variable defines the default value
+   for the *dir* argument to all the functions defined in this module.
+
+   If ``tempdir`` is unset or ``None`` at any call to any of the above functions,
+   Python searches a standard list of directories and sets *tempdir* to the first
+   one which the calling user can create files in.  The list is:
+
+   #. The directory named by the :envvar:`TMPDIR` environment variable.
+
+   #. The directory named by the :envvar:`TEMP` environment variable.
+
+   #. The directory named by the :envvar:`TMP` environment variable.
+
+   #. A platform-specific location:
+
+      * On RiscOS, the directory named by the :envvar:`Wimp$ScrapDir` environment
+        variable.
+
+      * On Windows, the directories :file:`C:\\TEMP`, :file:`C:\\TMP`,
+        :file:`\\TEMP`, and :file:`\\TMP`, in that order.
+
+      * On all other platforms, the directories :file:`/tmp`, :file:`/var/tmp`, and
+        :file:`/usr/tmp`, in that order.
+
+   #. As a last resort, the current working directory.
+
+
+.. function:: gettempdir()
+
+   Return the directory currently selected to create temporary files in. If
+   :data:`tempdir` is not ``None``, this simply returns its contents; otherwise,
+   the search described above is performed, and the result returned.
+
+
+.. data:: template
+
+   .. deprecated:: 2.0
+      Use :func:`gettempprefix` instead.
+
+   When set to a value other than ``None``, this variable defines the prefix of the
+   final component of the filenames returned by :func:`mktemp`.  A string of six
+   random letters and digits is appended to the prefix to make the filename unique.
+   On Windows, the default prefix is :file:`~T`; on all other systems it is
+   :file:`tmp`.
+
+   Older versions of this module used to require that ``template`` be set to
+   ``None`` after a call to :func:`os.fork`; this has not been necessary since
+   version 1.5.2.
+
+
+.. function:: gettempprefix()
+
+   Return the filename prefix used to create temporary files.  This does not
+   contain the directory component.  Using this function is preferred over reading
+   the *template* variable directly.
+
+   .. versionadded:: 1.5.2
+
diff --git a/Doc/library/termios.rst b/Doc/library/termios.rst
new file mode 100644
index 0000000..695faad
--- /dev/null
+++ b/Doc/library/termios.rst
@@ -0,0 +1,111 @@
+
+:mod:`termios` --- POSIX style tty control
+==========================================
+
+.. module:: termios
+   :platform: Unix
+   :synopsis: POSIX style tty control.
+
+
+.. index::
+   pair: POSIX; I/O control
+   pair: tty; I/O control
+
+This module provides an interface to the POSIX calls for tty I/O control.  For a
+complete description of these calls, see the POSIX or Unix manual pages.  It is
+only available for those Unix versions that support POSIX *termios* style tty
+I/O control (and then only if configured at installation time).
+
+All functions in this module take a file descriptor *fd* as their first
+argument.  This can be an integer file descriptor, such as returned by
+``sys.stdin.fileno()``, or a file object, such as ``sys.stdin`` itself.
+
+This module also defines all the constants needed to work with the functions
+provided here; these have the same name as their counterparts in C.  Please
+refer to your system documentation for more information on using these terminal
+control interfaces.
+
+The module defines the following functions:
+
+
+.. function:: tcgetattr(fd)
+
+   Return a list containing the tty attributes for file descriptor *fd*, as
+   follows: ``[iflag, oflag, cflag, lflag, ispeed, ospeed, cc]`` where *cc* is a
+   list of the tty special characters (each a string of length 1, except the
+   items with indices :const:`VMIN` and :const:`VTIME`, which are integers when
+   these fields are defined).  The interpretation of the flags and the speeds as
+   well as the indexing in the *cc* array must be done using the symbolic
+   constants defined in the :mod:`termios` module.
+
+
+.. function:: tcsetattr(fd, when, attributes)
+
+   Set the tty attributes for file descriptor *fd* from the *attributes*, which is
+   a list like the one returned by :func:`tcgetattr`.  The *when* argument
+   determines when the attributes are changed: :const:`TCSANOW` to change
+   immediately, :const:`TCSADRAIN` to change after transmitting all queued output,
+   or :const:`TCSAFLUSH` to change after transmitting all queued output and
+   discarding all queued input.
+
+
+.. function:: tcsendbreak(fd, duration)
+
+   Send a break on file descriptor *fd*.  A zero *duration* sends a break for 0.25
+   --0.5 seconds; a nonzero *duration* has a system dependent meaning.
+
+
+.. function:: tcdrain(fd)
+
+   Wait until all output written to file descriptor *fd* has been transmitted.
+
+
+.. function:: tcflush(fd, queue)
+
+   Discard queued data on file descriptor *fd*.  The *queue* selector specifies
+   which queue: :const:`TCIFLUSH` for the input queue, :const:`TCOFLUSH` for the
+   output queue, or :const:`TCIOFLUSH` for both queues.
+
+
+.. function:: tcflow(fd, action)
+
+   Suspend or resume input or output on file descriptor *fd*.  The *action*
+   argument can be :const:`TCOOFF` to suspend output, :const:`TCOON` to restart
+   output, :const:`TCIOFF` to suspend input, or :const:`TCION` to restart input.
+
+
+.. seealso::
+
+   Module :mod:`tty`
+      Convenience functions for common terminal control operations.
+
+
+Example
+-------
+
+.. _termios-example:
+
+Here's a function that prompts for a password with echoing turned off.  Note the
+technique using a separate :func:`tcgetattr` call and a :keyword:`try` ...
+:keyword:`finally` statement to ensure that the old tty attributes are restored
+exactly no matter what happens::
+
+   def raw_input(prompt):
+       import sys
+       sys.stdout.write(prompt)
+       sys.stdout.flush()
+       return sys.stdin.readline()
+
+   def getpass(prompt = "Password: "):
+       import termios, sys
+       fd = sys.stdin.fileno()
+       old = termios.tcgetattr(fd)
+       new = termios.tcgetattr(fd)
+       new[3] = new[3] & ~termios.ECHO          # lflags
+       try:
+           termios.tcsetattr(fd, termios.TCSADRAIN, new)
+           passwd = raw_input(prompt)
+       finally:
+           termios.tcsetattr(fd, termios.TCSADRAIN, old)
+       return passwd
+
diff --git a/Doc/library/test.rst b/Doc/library/test.rst
new file mode 100644
index 0000000..8972091
--- /dev/null
+++ b/Doc/library/test.rst
@@ -0,0 +1,317 @@
+
+:mod:`test` --- Regression tests package for Python
+===================================================
+
+.. module:: test
+   :synopsis: Regression tests package containing the testing suite for Python.
+.. sectionauthor:: Brett Cannon <brett@python.org>
+
+
+The :mod:`test` package contains all regression tests for Python as well as the
+modules :mod:`test.test_support` and :mod:`test.regrtest`.
+:mod:`test.test_support` is used to enhance your tests while
+:mod:`test.regrtest` drives the testing suite.
+
+Each module in the :mod:`test` package whose name starts with ``test_`` is a
+testing suite for a specific module or feature. All new tests should be written
+using the :mod:`unittest` or :mod:`doctest` module.  Some older tests are
+written using a "traditional" testing style that compares output printed to
+``sys.stdout``; this style of test is considered deprecated.
+
+
+.. seealso::
+
+   Module :mod:`unittest`
+      Writing PyUnit regression tests.
+
+   Module :mod:`doctest`
+      Tests embedded in documentation strings.
+
+
+.. _writing-tests:
+
+Writing Unit Tests for the :mod:`test` package
+----------------------------------------------
+
+.. % 
+
+It is preferred that tests that use the :mod:`unittest` module follow a few
+guidelines. One is to name the test module by starting it with ``test_`` and end
+it with the name of the module being tested. The test methods in the test module
+should start with ``test_`` and end with a description of what the method is
+testing. This is needed so that the methods are recognized by the test driver as
+test methods. Also, no documentation string for the method should be included. A
+comment (such as ``# Tests function returns only True or False``) should be used
+to provide documentation for test methods. This is done because documentation
+strings get printed out if they exist and thus what test is being run is not
+stated.
+
+A basic boilerplate is often used::
+
+   import unittest
+   from test import test_support
+
+   class MyTestCase1(unittest.TestCase):
+
+       # Only use setUp() and tearDown() if necessary
+
+       def setUp(self):
+           ... code to execute in preparation for tests ...
+
+       def tearDown(self):
+           ... code to execute to clean up after tests ...
+
+       def test_feature_one(self):
+           # Test feature one.
+           ... testing code ...
+
+       def test_feature_two(self):
+           # Test feature two.
+           ... testing code ...
+
+       ... more test methods ...
+
+   class MyTestCase2(unittest.TestCase):
+       ... same structure as MyTestCase1 ...
+
+   ... more test classes ...
+
+   def test_main():
+       test_support.run_unittest(MyTestCase1,
+                                 MyTestCase2,
+                                 ... list other tests ...
+                                )
+
+   if __name__ == '__main__':
+       test_main()
+
+This boilerplate code allows the testing suite to be run by :mod:`test.regrtest`
+as well as on its own as a script.
+
+The goal for regression testing is to try to break code. This leads to a few
+guidelines to be followed:
+
+* The testing suite should exercise all classes, functions, and constants. This
+  includes not just the external API that is to be presented to the outside world
+  but also "private" code.
+
+* Whitebox testing (examining the code being tested when the tests are being
+  written) is preferred. Blackbox testing (testing only the published user
+  interface) is not complete enough to make sure all boundary and edge cases are
+  tested.
+
+* Make sure all possible values are tested including invalid ones. This makes
+  sure that not only all valid values are acceptable but also that improper values
+  are handled correctly.
+
+* Exhaust as many code paths as possible. Test where branching occurs and thus
+  tailor input to make sure as many different paths through the code are taken.
+
+* Add an explicit test for any bugs discovered for the tested code. This will
+  make sure that the error does not crop up again if the code is changed in the
+  future.
+
+* Make sure to clean up after your tests (such as close and remove all temporary
+  files).
+
+* If a test is dependent on a specific condition of the operating system then
+  verify the condition already exists before attempting the test.
+
+* Import as few modules as possible and do it as soon as possible. This
+  minimizes external dependencies of tests and also minimizes possible anomalous
+  behavior from side-effects of importing a module.
+
+* Try to maximize code reuse. On occasion, tests will vary by something as small
+  as what type of input is used. Minimize code duplication by subclassing a basic
+  test class with a class that specifies the input::
+
+     class TestFuncAcceptsSequences(unittest.TestCase):
+
+         func = mySuperWhammyFunction
+
+         def test_func(self):
+             self.func(self.arg)
+
+     class AcceptLists(TestFuncAcceptsSequences):
+         arg = [1,2,3]
+
+     class AcceptStrings(TestFuncAcceptsSequences):
+         arg = 'abc'
+
+     class AcceptTuples(TestFuncAcceptsSequences):
+         arg = (1,2,3)
+
+
+.. seealso::
+
+   Test Driven Development
+      A book by Kent Beck on writing tests before code.
+
+
+.. _regrtest:
+
+Running tests using :mod:`test.regrtest`
+----------------------------------------
+
+:mod:`test.regrtest` can be used as a script to drive Python's regression test
+suite. Running the script by itself automatically starts running all regression
+tests in the :mod:`test` package. It does this by finding all modules in the
+package whose name starts with ``test_``, importing them, and executing the
+function :func:`test_main` if present. The names of tests to execute may also be
+passed to the script. Specifying a single regression test (:program:`python
+regrtest.py` :option:`test_spam.py`) will minimize output and only print whether
+the test passed or failed and thus minimize output.
+
+Running :mod:`test.regrtest` directly allows what resources are available for
+tests to use to be set. You do this by using the :option:`-u` command-line
+option. Run :program:`python regrtest.py` :option:`-uall` to turn on all
+resources; specifying :option:`all` as an option for :option:`-u` enables all
+possible resources. If all but one resource is desired (a more common case), a
+comma-separated list of resources that are not desired may be listed after
+:option:`all`. The command :program:`python regrtest.py`
+:option:`-uall,-audio,-largefile` will run :mod:`test.regrtest` with all
+resources except the :option:`audio` and :option:`largefile` resources. For a
+list of all resources and more command-line options, run :program:`python
+regrtest.py` :option:`-h`.
+
+Some other ways to execute the regression tests depend on what platform the
+tests are being executed on. On Unix, you can run :program:`make` :option:`test`
+at the top-level directory where Python was built. On Windows, executing
+:program:`rt.bat` from your :file:`PCBuild` directory will run all regression
+tests.
+
+
+:mod:`test.test_support` --- Utility functions for tests
+========================================================
+
+.. module:: test.test_support
+   :synopsis: Support for Python regression tests.
+
+
+The :mod:`test.test_support` module provides support for Python's regression
+tests.
+
+This module defines the following exceptions:
+
+
+.. exception:: TestFailed
+
+   Exception to be raised when a test fails. This is deprecated in favor of
+   :mod:`unittest`\ -based tests and :class:`unittest.TestCase`'s assertion
+   methods.
+
+
+.. exception:: TestSkipped
+
+   Subclass of :exc:`TestFailed`. Raised when a test is skipped. This occurs when a
+   needed resource (such as a network connection) is not available at the time of
+   testing.
+
+
+.. exception:: ResourceDenied
+
+   Subclass of :exc:`TestSkipped`. Raised when a resource (such as a network
+   connection) is not available. Raised by the :func:`requires` function.
+
+The :mod:`test.test_support` module defines the following constants:
+
+
+.. data:: verbose
+
+   :const:`True` when verbose output is enabled. Should be checked when more
+   detailed information is desired about a running test. *verbose* is set by
+   :mod:`test.regrtest`.
+
+
+.. data:: have_unicode
+
+   :const:`True` when Unicode support is available.
+
+
+.. data:: is_jython
+
+   :const:`True` if the running interpreter is Jython.
+
+
+.. data:: TESTFN
+
+   Set to the path that a temporary file may be created at. Any temporary that is
+   created should be closed and unlinked (removed).
+
+The :mod:`test.test_support` module defines the following functions:
+
+
+.. function:: forget(module_name)
+
+   Removes the module named *module_name* from ``sys.modules`` and deletes any
+   byte-compiled files of the module.
+
+
+.. function:: is_resource_enabled(resource)
+
+   Returns :const:`True` if *resource* is enabled and available. The list of
+   available resources is only set when :mod:`test.regrtest` is executing the
+   tests.
+
+
+.. function:: requires(resource[, msg])
+
+   Raises :exc:`ResourceDenied` if *resource* is not available. *msg* is the
+   argument to :exc:`ResourceDenied` if it is raised. Always returns true if called
+   by a function whose ``__name__`` is ``'__main__'``. Used when tests are executed
+   by :mod:`test.regrtest`.
+
+
+.. function:: findfile(filename)
+
+   Return the path to the file named *filename*. If no match is found *filename* is
+   returned. This does not equal a failure since it could be the path to the file.
+
+
+.. function:: run_unittest(*classes)
+
+   Execute :class:`unittest.TestCase` subclasses passed to the function. The
+   function scans the classes for methods starting with the prefix ``test_`` and
+   executes the tests individually.
+
+   It is also legal to pass strings as parameters; these should be keys in
+   ``sys.modules``. Each associated module will be scanned by
+   ``unittest.TestLoader.loadTestsFromModule()``. This is usually seen in the
+   following :func:`test_main` function::
+
+      def test_main():
+          test_support.run_unittest(__name__)
+
+   This will run all tests defined in the named module.
+
+The :mod:`test.test_support` module defines the following classes:
+
+
+.. class:: TransientResource(exc[, **kwargs])
+
+   Instances are a context manager that raises :exc:`ResourceDenied` if the
+   specified exception type is raised.  Any keyword arguments are treated as
+   attribute/value pairs to be compared against any exception raised within the
+   :keyword:`with` statement.  Only if all pairs match properly against
+   attributes on the exception is :exc:`ResourceDenied` raised.
+
+   .. versionadded:: 2.6
+
+
+.. class:: EnvironmentVarGuard()
+
+   Class used to temporarily set or unset environment variables.  Instances can be
+   used as a context manager.
+
+   .. versionadded:: 2.6
+
+
+.. method:: EnvironmentVarGuard.set(envvar, value)
+
+   Temporarily set the environment variable ``envvar`` to the value of ``value``.
+
+
+.. method:: EnvironmentVarGuard.unset(envvar)
+
+   Temporarily unset the environment variable ``envvar``.
+
diff --git a/Doc/library/textwrap.rst b/Doc/library/textwrap.rst
new file mode 100644
index 0000000..f729a64
--- /dev/null
+++ b/Doc/library/textwrap.rst
@@ -0,0 +1,192 @@
+
+:mod:`textwrap` --- Text wrapping and filling
+=============================================
+
+.. module:: textwrap
+   :synopsis: Text wrapping and filling
+.. moduleauthor:: Greg Ward <gward@python.net>
+.. sectionauthor:: Greg Ward <gward@python.net>
+
+
+.. versionadded:: 2.3
+
+The :mod:`textwrap` module provides two convenience functions, :func:`wrap` and
+:func:`fill`, as well as :class:`TextWrapper`, the class that does all the work,
+and a utility function  :func:`dedent`.  If you're just wrapping or filling one
+or two  text strings, the convenience functions should be good enough;
+otherwise,  you should use an instance of :class:`TextWrapper` for efficiency.
+
+
+.. function:: wrap(text[, width[, ...]])
+
+   Wraps the single paragraph in *text* (a string) so every line is at most *width*
+   characters long.  Returns a list of output lines, without final newlines.
+
+   Optional keyword arguments correspond to the instance attributes of
+   :class:`TextWrapper`, documented below.  *width* defaults to ``70``.
+
+
+.. function:: fill(text[, width[, ...]])
+
+   Wraps the single paragraph in *text*, and returns a single string containing the
+   wrapped paragraph.  :func:`fill` is shorthand for  ::
+
+      "\n".join(wrap(text, ...))
+
+   In particular, :func:`fill` accepts exactly the same keyword arguments as
+   :func:`wrap`.
+
+Both :func:`wrap` and :func:`fill` work by creating a :class:`TextWrapper`
+instance and calling a single method on it.  That instance is not reused, so for
+applications that wrap/fill many text strings, it will be more efficient for you
+to create your own :class:`TextWrapper` object.
+
+An additional utility function, :func:`dedent`, is provided to remove
+indentation from strings that have unwanted whitespace to the left of the text.
+
+
+.. function:: dedent(text)
+
+   Remove any common leading whitespace from every line in *text*.
+
+   This can be used to make triple-quoted strings line up with the left edge of the
+   display, while still presenting them in the source code in indented form.
+
+   Note that tabs and spaces are both treated as whitespace, but they are not
+   equal: the lines ``"  hello"`` and ``"\thello"`` are considered to have no
+   common leading whitespace.  (This behaviour is new in Python 2.5; older versions
+   of this module incorrectly expanded tabs before searching for common leading
+   whitespace.)
+
+   For example::
+
+      def test():
+          # end first line with \ to avoid the empty line!
+          s = '''\
+          hello
+            world
+          '''
+          print repr(s)          # prints '    hello\n      world\n    '
+          print repr(dedent(s))  # prints 'hello\n  world\n'
+
+
+.. class:: TextWrapper(...)
+
+   The :class:`TextWrapper` constructor accepts a number of optional keyword
+   arguments.  Each argument corresponds to one instance attribute, so for example
+   ::
+
+      wrapper = TextWrapper(initial_indent="* ")
+
+   is the same as  ::
+
+      wrapper = TextWrapper()
+      wrapper.initial_indent = "* "
+
+   You can re-use the same :class:`TextWrapper` object many times, and you can
+   change any of its options through direct assignment to instance attributes
+   between uses.
+
+The :class:`TextWrapper` instance attributes (and keyword arguments to the
+constructor) are as follows:
+
+
+.. attribute:: TextWrapper.width
+
+   (default: ``70``) The maximum length of wrapped lines.  As long as there are no
+   individual words in the input text longer than :attr:`width`,
+   :class:`TextWrapper` guarantees that no output line will be longer than
+   :attr:`width` characters.
+
+
+.. attribute:: TextWrapper.expand_tabs
+
+   (default: ``True``) If true, then all tab characters in *text* will be expanded
+   to spaces using the :meth:`expandtabs` method of *text*.
+
+
+.. attribute:: TextWrapper.replace_whitespace
+
+   (default: ``True``) If true, each whitespace character (as defined by
+   ``string.whitespace``) remaining after tab expansion will be replaced by a
+   single space.
+
+   .. note::
+
+      If :attr:`expand_tabs` is false and :attr:`replace_whitespace` is true, each tab
+      character will be replaced by a single space, which is *not* the same as tab
+      expansion.
+
+
+.. attribute:: TextWrapper.drop_whitespace
+
+   (default: ``True``) If true, whitespace that, after wrapping, happens to end up
+   at the beginning or end of a line is dropped (leading whitespace in the first
+   line is always preserved, though).
+
+   .. versionadded:: 2.6
+      Whitespace was always dropped in earlier versions.
+
+
+.. attribute:: TextWrapper.initial_indent
+
+   (default: ``''``) String that will be prepended to the first line of wrapped
+   output.  Counts towards the length of the first line.
+
+
+.. attribute:: TextWrapper.subsequent_indent
+
+   (default: ``''``) String that will be prepended to all lines of wrapped output
+   except the first.  Counts towards the length of each line except the first.
+
+
+.. attribute:: TextWrapper.fix_sentence_endings
+
+   (default: ``False``) If true, :class:`TextWrapper` attempts to detect sentence
+   endings and ensure that sentences are always separated by exactly two spaces.
+   This is generally desired for text in a monospaced font.  However, the sentence
+   detection algorithm is imperfect: it assumes that a sentence ending consists of
+   a lowercase letter followed by one of ``'.'``, ``'!'``, or ``'?'``, possibly
+   followed by one of ``'"'`` or ``"'"``, followed by a space.  One problem with
+   this is algorithm is that it is unable to detect the difference between "Dr." in
+   ::
+
+      [...] Dr. Frankenstein's monster [...]
+
+   and "Spot." in ::
+
+      [...] See Spot. See Spot run [...]
+
+   :attr:`fix_sentence_endings` is false by default.
+
+   Since the sentence detection algorithm relies on ``string.lowercase`` for the
+   definition of "lowercase letter," and a convention of using two spaces after
+   a period to separate sentences on the same line, it is specific to
+   English-language texts.
+
+
+.. attribute:: TextWrapper.break_long_words
+
+   (default: ``True``) If true, then words longer than :attr:`width` will be broken
+   in order to ensure that no lines are longer than :attr:`width`.  If it is false,
+   long words will not be broken, and some lines may be longer than :attr:`width`.
+   (Long words will be put on a line by themselves, in order to minimize the amount
+   by which :attr:`width` is exceeded.)
+
+:class:`TextWrapper` also provides two public methods, analogous to the
+module-level convenience functions:
+
+
+.. method:: TextWrapper.wrap(text)
+
+   Wraps the single paragraph in *text* (a string) so every line is at most
+   :attr:`width` characters long.  All wrapping options are taken from instance
+   attributes of the :class:`TextWrapper` instance. Returns a list of output lines,
+   without final newlines.
+
+
+.. method:: TextWrapper.fill(text)
+
+   Wraps the single paragraph in *text*, and returns a single string containing the
+   wrapped paragraph.
+
diff --git a/Doc/library/thread.rst b/Doc/library/thread.rst
new file mode 100644
index 0000000..c9be598
--- /dev/null
+++ b/Doc/library/thread.rst
@@ -0,0 +1,171 @@
+
+:mod:`thread` --- Multiple threads of control
+=============================================
+
+.. module:: thread
+   :synopsis: Create multiple threads of control within one interpreter.
+
+
+.. index::
+   single: light-weight processes
+   single: processes, light-weight
+   single: binary semaphores
+   single: semaphores, binary
+
+This module provides low-level primitives for working with multiple threads
+(a.k.a. :dfn:`light-weight processes` or :dfn:`tasks`) --- multiple threads of
+control sharing their global data space.  For synchronization, simple locks
+(a.k.a. :dfn:`mutexes` or :dfn:`binary semaphores`) are provided.
+
+.. index::
+   single: pthreads
+   pair: threads; POSIX
+
+The module is optional.  It is supported on Windows, Linux, SGI IRIX, Solaris
+2.x, as well as on systems that have a POSIX thread (a.k.a. "pthread")
+implementation.  For systems lacking the :mod:`thread` module, the
+:mod:`dummy_thread` module is available. It duplicates this module's interface
+and can be used as a drop-in replacement.
+
+It defines the following constant and functions:
+
+
+.. exception:: error
+
+   Raised on thread-specific errors.
+
+
+.. data:: LockType
+
+   This is the type of lock objects.
+
+
+.. function:: start_new_thread(function, args[, kwargs])
+
+   Start a new thread and return its identifier.  The thread executes the function
+   *function* with the argument list *args* (which must be a tuple).  The optional
+   *kwargs* argument specifies a dictionary of keyword arguments. When the function
+   returns, the thread silently exits.  When the function terminates with an
+   unhandled exception, a stack trace is printed and then the thread exits (but
+   other threads continue to run).
+
+
+.. function:: interrupt_main()
+
+   Raise a :exc:`KeyboardInterrupt` exception in the main thread.  A subthread can
+   use this function to interrupt the main thread.
+
+   .. versionadded:: 2.3
+
+
+.. function:: exit()
+
+   Raise the :exc:`SystemExit` exception.  When not caught, this will cause the
+   thread to exit silently.
+
+.. % \begin{funcdesc}{exit_prog}{status}
+.. % Exit all threads and report the value of the integer argument
+.. % \var{status} as the exit status of the entire program.
+.. % \strong{Caveat:} code in pending \keyword{finally} clauses, in this thread
+.. % or in other threads, is not executed.
+.. % \end{funcdesc}
+
+
+.. function:: allocate_lock()
+
+   Return a new lock object.  Methods of locks are described below.  The lock is
+   initially unlocked.
+
+
+.. function:: get_ident()
+
+   Return the 'thread identifier' of the current thread.  This is a nonzero
+   integer.  Its value has no direct meaning; it is intended as a magic cookie to
+   be used e.g. to index a dictionary of thread-specific data.  Thread identifiers
+   may be recycled when a thread exits and another thread is created.
+
+
+.. function:: stack_size([size])
+
+   Return the thread stack size used when creating new threads.  The optional
+   *size* argument specifies the stack size to be used for subsequently created
+   threads, and must be 0 (use platform or configured default) or a positive
+   integer value of at least 32,768 (32kB). If changing the thread stack size is
+   unsupported, a :exc:`ThreadError` is raised.  If the specified stack size is
+   invalid, a :exc:`ValueError` is raised and the stack size is unmodified.  32kB
+   is currently the minimum supported stack size value to guarantee sufficient
+   stack space for the interpreter itself.  Note that some platforms may have
+   particular restrictions on values for the stack size, such as requiring a
+   minimum stack size > 32kB or requiring allocation in multiples of the system
+   memory page size - platform documentation should be referred to for more
+   information (4kB pages are common; using multiples of 4096 for the stack size is
+   the suggested approach in the absence of more specific information).
+   Availability: Windows, systems with POSIX threads.
+
+   .. versionadded:: 2.5
+
+Lock objects have the following methods:
+
+
+.. method:: lock.acquire([waitflag])
+
+   Without the optional argument, this method acquires the lock unconditionally, if
+   necessary waiting until it is released by another thread (only one thread at a
+   time can acquire a lock --- that's their reason for existence).  If the integer
+   *waitflag* argument is present, the action depends on its value: if it is zero,
+   the lock is only acquired if it can be acquired immediately without waiting,
+   while if it is nonzero, the lock is acquired unconditionally as before.  The
+   return value is ``True`` if the lock is acquired successfully, ``False`` if not.
+
+
+.. method:: lock.release()
+
+   Releases the lock.  The lock must have been acquired earlier, but not
+   necessarily by the same thread.
+
+
+.. method:: lock.locked()
+
+   Return the status of the lock: ``True`` if it has been acquired by some thread,
+   ``False`` if not.
+
+In addition to these methods, lock objects can also be used via the
+:keyword:`with` statement, e.g.::
+
+   from __future__ import with_statement
+   import thread
+
+   a_lock = thread.allocate_lock()
+
+   with a_lock:
+       print "a_lock is locked while this executes"
+
+**Caveats:**
+
+  .. index:: module: signal
+
+* Threads interact strangely with interrupts: the :exc:`KeyboardInterrupt`
+  exception will be received by an arbitrary thread.  (When the :mod:`signal`
+  module is available, interrupts always go to the main thread.)
+
+* Calling :func:`sys.exit` or raising the :exc:`SystemExit` exception is
+  equivalent to calling :func:`exit`.
+
+* Not all built-in functions that may block waiting for I/O allow other threads
+  to run.  (The most popular ones (:func:`time.sleep`, :meth:`file.read`,
+  :func:`select.select`) work as expected.)
+
+* It is not possible to interrupt the :meth:`acquire` method on a lock --- the
+  :exc:`KeyboardInterrupt` exception will happen after the lock has been acquired.
+
+  .. index:: pair: threads; IRIX
+
+* When the main thread exits, it is system defined whether the other threads
+  survive.  On SGI IRIX using the native thread implementation, they survive.  On
+  most other systems, they are killed without executing :keyword:`try` ...
+  :keyword:`finally` clauses or executing object destructors.
+
+* When the main thread exits, it does not do any of its usual cleanup (except
+  that :keyword:`try` ... :keyword:`finally` clauses are honored), and the
+  standard I/O files are not flushed.
+
diff --git a/Doc/library/threading.rst b/Doc/library/threading.rst
new file mode 100644
index 0000000..92ce02a
--- /dev/null
+++ b/Doc/library/threading.rst
@@ -0,0 +1,732 @@
+
+:mod:`threading` --- Higher-level threading interface
+=====================================================
+
+.. module:: threading
+   :synopsis: Higher-level threading interface.
+
+
+This module constructs higher-level threading interfaces on top of the  lower
+level :mod:`thread` module.
+
+The :mod:`dummy_threading` module is provided for situations where
+:mod:`threading` cannot be used because :mod:`thread` is missing.
+
+This module defines the following functions and objects:
+
+
+.. function:: activeCount()
+
+   Return the number of :class:`Thread` objects currently alive.  The returned
+   count is equal to the length of the list returned by :func:`enumerate`.
+
+
+.. function:: Condition()
+   :noindex:
+
+   A factory function that returns a new condition variable object. A condition
+   variable allows one or more threads to wait until they are notified by another
+   thread.
+
+
+.. function:: currentThread()
+
+   Return the current :class:`Thread` object, corresponding to the caller's thread
+   of control.  If the caller's thread of control was not created through the
+   :mod:`threading` module, a dummy thread object with limited functionality is
+   returned.
+
+
+.. function:: enumerate()
+
+   Return a list of all :class:`Thread` objects currently alive.  The list includes
+   daemonic threads, dummy thread objects created by :func:`currentThread`, and the
+   main thread.  It excludes terminated threads and threads that have not yet been
+   started.
+
+
+.. function:: Event()
+   :noindex:
+
+   A factory function that returns a new event object.  An event manages a flag
+   that can be set to true with the :meth:`set` method and reset to false with the
+   :meth:`clear` method.  The :meth:`wait` method blocks until the flag is true.
+
+
+.. class:: local
+
+   A class that represents thread-local data.  Thread-local data are data whose
+   values are thread specific.  To manage thread-local data, just create an
+   instance of :class:`local` (or a subclass) and store attributes on it::
+
+      mydata = threading.local()
+      mydata.x = 1
+
+   The instance's values will be different for separate threads.
+
+   For more details and extensive examples, see the documentation string of the
+   :mod:`_threading_local` module.
+
+   .. versionadded:: 2.4
+
+
+.. function:: Lock()
+
+   A factory function that returns a new primitive lock object.  Once a thread has
+   acquired it, subsequent attempts to acquire it block, until it is released; any
+   thread may release it.
+
+
+.. function:: RLock()
+
+   A factory function that returns a new reentrant lock object. A reentrant lock
+   must be released by the thread that acquired it. Once a thread has acquired a
+   reentrant lock, the same thread may acquire it again without blocking; the
+   thread must release it once for each time it has acquired it.
+
+
+.. function:: Semaphore([value])
+   :noindex:
+
+   A factory function that returns a new semaphore object.  A semaphore manages a
+   counter representing the number of :meth:`release` calls minus the number of
+   :meth:`acquire` calls, plus an initial value. The :meth:`acquire` method blocks
+   if necessary until it can return without making the counter negative.  If not
+   given, *value* defaults to 1.
+
+
+.. function:: BoundedSemaphore([value])
+
+   A factory function that returns a new bounded semaphore object.  A bounded
+   semaphore checks to make sure its current value doesn't exceed its initial
+   value.  If it does, :exc:`ValueError` is raised. In most situations semaphores
+   are used to guard resources with limited capacity.  If the semaphore is released
+   too many times it's a sign of a bug.  If not given, *value* defaults to 1.
+
+
+.. class:: Thread
+
+   A class that represents a thread of control.  This class can be safely
+   subclassed in a limited fashion.
+
+
+.. class:: Timer
+
+   A thread that executes a function after a specified interval has passed.
+
+
+.. function:: settrace(func)
+
+   .. index:: single: trace function
+
+   Set a trace function for all threads started from the :mod:`threading` module.
+   The *func* will be passed to  :func:`sys.settrace` for each thread, before its
+   :meth:`run` method is called.
+
+   .. versionadded:: 2.3
+
+
+.. function:: setprofile(func)
+
+   .. index:: single: profile function
+
+   Set a profile function for all threads started from the :mod:`threading` module.
+   The *func* will be passed to  :func:`sys.setprofile` for each thread, before its
+   :meth:`run` method is called.
+
+   .. versionadded:: 2.3
+
+
+.. function:: stack_size([size])
+
+   Return the thread stack size used when creating new threads.  The optional
+   *size* argument specifies the stack size to be used for subsequently created
+   threads, and must be 0 (use platform or configured default) or a positive
+   integer value of at least 32,768 (32kB). If changing the thread stack size is
+   unsupported, a :exc:`ThreadError` is raised.  If the specified stack size is
+   invalid, a :exc:`ValueError` is raised and the stack size is unmodified.  32kB
+   is currently the minimum supported stack size value to guarantee sufficient
+   stack space for the interpreter itself.  Note that some platforms may have
+   particular restrictions on values for the stack size, such as requiring a
+   minimum stack size > 32kB or requiring allocation in multiples of the system
+   memory page size - platform documentation should be referred to for more
+   information (4kB pages are common; using multiples of 4096 for the stack size is
+   the suggested approach in the absence of more specific information).
+   Availability: Windows, systems with POSIX threads.
+
+   .. versionadded:: 2.5
+
+Detailed interfaces for the objects are documented below.
+
+The design of this module is loosely based on Java's threading model. However,
+where Java makes locks and condition variables basic behavior of every object,
+they are separate objects in Python.  Python's :class:`Thread` class supports a
+subset of the behavior of Java's Thread class; currently, there are no
+priorities, no thread groups, and threads cannot be destroyed, stopped,
+suspended, resumed, or interrupted.  The static methods of Java's Thread class,
+when implemented, are mapped to module-level functions.
+
+All of the methods described below are executed atomically.
+
+
+.. _lock-objects:
+
+Lock Objects
+------------
+
+A primitive lock is a synchronization primitive that is not owned by a
+particular thread when locked.  In Python, it is currently the lowest level
+synchronization primitive available, implemented directly by the :mod:`thread`
+extension module.
+
+A primitive lock is in one of two states, "locked" or "unlocked". It is created
+in the unlocked state.  It has two basic methods, :meth:`acquire` and
+:meth:`release`.  When the state is unlocked, :meth:`acquire` changes the state
+to locked and returns immediately.  When the state is locked, :meth:`acquire`
+blocks until a call to :meth:`release` in another thread changes it to unlocked,
+then the :meth:`acquire` call resets it to locked and returns.  The
+:meth:`release` method should only be called in the locked state; it changes the
+state to unlocked and returns immediately. If an attempt is made to release an
+unlocked lock, a :exc:`RuntimeError` will be raised.
+
+When more than one thread is blocked in :meth:`acquire` waiting for the state to
+turn to unlocked, only one thread proceeds when a :meth:`release` call resets
+the state to unlocked; which one of the waiting threads proceeds is not defined,
+and may vary across implementations.
+
+All methods are executed atomically.
+
+
+.. method:: Lock.acquire([blocking=1])
+
+   Acquire a lock, blocking or non-blocking.
+
+   When invoked without arguments, block until the lock is unlocked, then set it to
+   locked, and return true.
+
+   When invoked with the *blocking* argument set to true, do the same thing as when
+   called without arguments, and return true.
+
+   When invoked with the *blocking* argument set to false, do not block.  If a call
+   without an argument would block, return false immediately; otherwise, do the
+   same thing as when called without arguments, and return true.
+
+
+.. method:: Lock.release()
+
+   Release a lock.
+
+   When the lock is locked, reset it to unlocked, and return.  If any other threads
+   are blocked waiting for the lock to become unlocked, allow exactly one of them
+   to proceed.
+
+   Do not call this method when the lock is unlocked.
+
+   There is no return value.
+
+
+.. _rlock-objects:
+
+RLock Objects
+-------------
+
+A reentrant lock is a synchronization primitive that may be acquired multiple
+times by the same thread.  Internally, it uses the concepts of "owning thread"
+and "recursion level" in addition to the locked/unlocked state used by primitive
+locks.  In the locked state, some thread owns the lock; in the unlocked state,
+no thread owns it.
+
+To lock the lock, a thread calls its :meth:`acquire` method; this returns once
+the thread owns the lock.  To unlock the lock, a thread calls its
+:meth:`release` method. :meth:`acquire`/:meth:`release` call pairs may be
+nested; only the final :meth:`release` (the :meth:`release` of the outermost
+pair) resets the lock to unlocked and allows another thread blocked in
+:meth:`acquire` to proceed.
+
+
+.. method:: RLock.acquire([blocking=1])
+
+   Acquire a lock, blocking or non-blocking.
+
+   When invoked without arguments: if this thread already owns the lock, increment
+   the recursion level by one, and return immediately.  Otherwise, if another
+   thread owns the lock, block until the lock is unlocked.  Once the lock is
+   unlocked (not owned by any thread), then grab ownership, set the recursion level
+   to one, and return.  If more than one thread is blocked waiting until the lock
+   is unlocked, only one at a time will be able to grab ownership of the lock.
+   There is no return value in this case.
+
+   When invoked with the *blocking* argument set to true, do the same thing as when
+   called without arguments, and return true.
+
+   When invoked with the *blocking* argument set to false, do not block.  If a call
+   without an argument would block, return false immediately; otherwise, do the
+   same thing as when called without arguments, and return true.
+
+
+.. method:: RLock.release()
+
+   Release a lock, decrementing the recursion level.  If after the decrement it is
+   zero, reset the lock to unlocked (not owned by any thread), and if any other
+   threads are blocked waiting for the lock to become unlocked, allow exactly one
+   of them to proceed.  If after the decrement the recursion level is still
+   nonzero, the lock remains locked and owned by the calling thread.
+
+   Only call this method when the calling thread owns the lock. A
+   :exc:`RuntimeError` is raised if this method is called when the lock is
+   unlocked.
+
+   There is no return value.
+
+
+.. _condition-objects:
+
+Condition Objects
+-----------------
+
+A condition variable is always associated with some kind of lock; this can be
+passed in or one will be created by default.  (Passing one in is useful when
+several condition variables must share the same lock.)
+
+A condition variable has :meth:`acquire` and :meth:`release` methods that call
+the corresponding methods of the associated lock. It also has a :meth:`wait`
+method, and :meth:`notify` and :meth:`notifyAll` methods.  These three must only
+be called when the calling thread has acquired the lock, otherwise a
+:exc:`RuntimeError` is raised.
+
+The :meth:`wait` method releases the lock, and then blocks until it is awakened
+by a :meth:`notify` or :meth:`notifyAll` call for the same condition variable in
+another thread.  Once awakened, it re-acquires the lock and returns.  It is also
+possible to specify a timeout.
+
+The :meth:`notify` method wakes up one of the threads waiting for the condition
+variable, if any are waiting.  The :meth:`notifyAll` method wakes up all threads
+waiting for the condition variable.
+
+Note: the :meth:`notify` and :meth:`notifyAll` methods don't release the lock;
+this means that the thread or threads awakened will not return from their
+:meth:`wait` call immediately, but only when the thread that called
+:meth:`notify` or :meth:`notifyAll` finally relinquishes ownership of the lock.
+
+Tip: the typical programming style using condition variables uses the lock to
+synchronize access to some shared state; threads that are interested in a
+particular change of state call :meth:`wait` repeatedly until they see the
+desired state, while threads that modify the state call :meth:`notify` or
+:meth:`notifyAll` when they change the state in such a way that it could
+possibly be a desired state for one of the waiters.  For example, the following
+code is a generic producer-consumer situation with unlimited buffer capacity::
+
+   # Consume one item
+   cv.acquire()
+   while not an_item_is_available():
+       cv.wait()
+   get_an_available_item()
+   cv.release()
+
+   # Produce one item
+   cv.acquire()
+   make_an_item_available()
+   cv.notify()
+   cv.release()
+
+To choose between :meth:`notify` and :meth:`notifyAll`, consider whether one
+state change can be interesting for only one or several waiting threads.  E.g.
+in a typical producer-consumer situation, adding one item to the buffer only
+needs to wake up one consumer thread.
+
+
+.. class:: Condition([lock])
+
+   If the *lock* argument is given and not ``None``, it must be a :class:`Lock` or
+   :class:`RLock` object, and it is used as the underlying lock.  Otherwise, a new
+   :class:`RLock` object is created and used as the underlying lock.
+
+
+.. method:: Condition.acquire(*args)
+
+   Acquire the underlying lock. This method calls the corresponding method on the
+   underlying lock; the return value is whatever that method returns.
+
+
+.. method:: Condition.release()
+
+   Release the underlying lock. This method calls the corresponding method on the
+   underlying lock; there is no return value.
+
+
+.. method:: Condition.wait([timeout])
+
+   Wait until notified or until a timeout occurs. If the calling thread has not
+   acquired the lock when this method is called, a :exc:`RuntimeError` is raised.
+
+   This method releases the underlying lock, and then blocks until it is awakened
+   by a :meth:`notify` or :meth:`notifyAll` call for the same condition variable in
+   another thread, or until the optional timeout occurs.  Once awakened or timed
+   out, it re-acquires the lock and returns.
+
+   When the *timeout* argument is present and not ``None``, it should be a floating
+   point number specifying a timeout for the operation in seconds (or fractions
+   thereof).
+
+   When the underlying lock is an :class:`RLock`, it is not released using its
+   :meth:`release` method, since this may not actually unlock the lock when it was
+   acquired multiple times recursively.  Instead, an internal interface of the
+   :class:`RLock` class is used, which really unlocks it even when it has been
+   recursively acquired several times. Another internal interface is then used to
+   restore the recursion level when the lock is reacquired.
+
+
+.. method:: Condition.notify()
+
+   Wake up a thread waiting on this condition, if any. Wait until notified or until
+   a timeout occurs. If the calling thread has not acquired the lock when this
+   method is called, a :exc:`RuntimeError` is raised.
+
+   This method wakes up one of the threads waiting for the condition variable, if
+   any are waiting; it is a no-op if no threads are waiting.
+
+   The current implementation wakes up exactly one thread, if any are waiting.
+   However, it's not safe to rely on this behavior.  A future, optimized
+   implementation may occasionally wake up more than one thread.
+
+   Note: the awakened thread does not actually return from its :meth:`wait` call
+   until it can reacquire the lock.  Since :meth:`notify` does not release the
+   lock, its caller should.
+
+
+.. method:: Condition.notifyAll()
+
+   Wake up all threads waiting on this condition.  This method acts like
+   :meth:`notify`, but wakes up all waiting threads instead of one. If the calling
+   thread has not acquired the lock when this method is called, a
+   :exc:`RuntimeError` is raised.
+
+
+.. _semaphore-objects:
+
+Semaphore Objects
+-----------------
+
+This is one of the oldest synchronization primitives in the history of computer
+science, invented by the early Dutch computer scientist Edsger W. Dijkstra (he
+used :meth:`P` and :meth:`V` instead of :meth:`acquire` and :meth:`release`).
+
+A semaphore manages an internal counter which is decremented by each
+:meth:`acquire` call and incremented by each :meth:`release` call.  The counter
+can never go below zero; when :meth:`acquire` finds that it is zero, it blocks,
+waiting until some other thread calls :meth:`release`.
+
+
+.. class:: Semaphore([value])
+
+   The optional argument gives the initial *value* for the internal counter; it
+   defaults to ``1``. If the *value* given is less than 0, :exc:`ValueError` is
+   raised.
+
+
+.. method:: Semaphore.acquire([blocking])
+
+   Acquire a semaphore.
+
+   When invoked without arguments: if the internal counter is larger than zero on
+   entry, decrement it by one and return immediately.  If it is zero on entry,
+   block, waiting until some other thread has called :meth:`release` to make it
+   larger than zero.  This is done with proper interlocking so that if multiple
+   :meth:`acquire` calls are blocked, :meth:`release` will wake exactly one of them
+   up.  The implementation may pick one at random, so the order in which blocked
+   threads are awakened should not be relied on.  There is no return value in this
+   case.
+
+   When invoked with *blocking* set to true, do the same thing as when called
+   without arguments, and return true.
+
+   When invoked with *blocking* set to false, do not block.  If a call without an
+   argument would block, return false immediately; otherwise, do the same thing as
+   when called without arguments, and return true.
+
+
+.. method:: Semaphore.release()
+
+   Release a semaphore, incrementing the internal counter by one.  When it was zero
+   on entry and another thread is waiting for it to become larger than zero again,
+   wake up that thread.
+
+
+.. _semaphore-examples:
+
+:class:`Semaphore` Example
+^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Semaphores are often used to guard resources with limited capacity, for example,
+a database server.  In any situation where the size of the resource size is
+fixed, you should use a bounded semaphore.  Before spawning any worker threads,
+your main thread would initialize the semaphore::
+
+   maxconnections = 5
+   ...
+   pool_sema = BoundedSemaphore(value=maxconnections)
+
+Once spawned, worker threads call the semaphore's acquire and release methods
+when they need to connect to the server::
+
+   pool_sema.acquire()
+   conn = connectdb()
+   ... use connection ...
+   conn.close()
+   pool_sema.release()
+
+The use of a bounded semaphore reduces the chance that a programming error which
+causes the semaphore to be released more than it's acquired will go undetected.
+
+
+.. _event-objects:
+
+Event Objects
+-------------
+
+This is one of the simplest mechanisms for communication between threads: one
+thread signals an event and other threads wait for it.
+
+An event object manages an internal flag that can be set to true with the
+:meth:`set` method and reset to false with the :meth:`clear` method.  The
+:meth:`wait` method blocks until the flag is true.
+
+
+.. class:: Event()
+
+   The internal flag is initially false.
+
+
+.. method:: Event.isSet()
+
+   Return true if and only if the internal flag is true.
+
+
+.. method:: Event.set()
+
+   Set the internal flag to true. All threads waiting for it to become true are
+   awakened. Threads that call :meth:`wait` once the flag is true will not block at
+   all.
+
+
+.. method:: Event.clear()
+
+   Reset the internal flag to false. Subsequently, threads calling :meth:`wait`
+   will block until :meth:`set` is called to set the internal flag to true again.
+
+
+.. method:: Event.wait([timeout])
+
+   Block until the internal flag is true. If the internal flag is true on entry,
+   return immediately.  Otherwise, block until another thread calls :meth:`set` to
+   set the flag to true, or until the optional timeout occurs.
+
+   When the timeout argument is present and not ``None``, it should be a floating
+   point number specifying a timeout for the operation in seconds (or fractions
+   thereof).
+
+
+.. _thread-objects:
+
+Thread Objects
+--------------
+
+This class represents an activity that is run in a separate thread of control.
+There are two ways to specify the activity: by passing a callable object to the
+constructor, or by overriding the :meth:`run` method in a subclass.  No other
+methods (except for the constructor) should be overridden in a subclass.  In
+other words,  *only*  override the :meth:`__init__` and :meth:`run` methods of
+this class.
+
+Once a thread object is created, its activity must be started by calling the
+thread's :meth:`start` method.  This invokes the :meth:`run` method in a
+separate thread of control.
+
+Once the thread's activity is started, the thread is considered 'alive'. It
+stops being alive when its :meth:`run` method terminates -- either normally, or
+by raising an unhandled exception.  The :meth:`isAlive` method tests whether the
+thread is alive.
+
+Other threads can call a thread's :meth:`join` method.  This blocks the calling
+thread until the thread whose :meth:`join` method is called is terminated.
+
+A thread has a name.  The name can be passed to the constructor, set with the
+:meth:`setName` method, and retrieved with the :meth:`getName` method.
+
+A thread can be flagged as a "daemon thread".  The significance of this flag is
+that the entire Python program exits when only daemon threads are left.  The
+initial value is inherited from the creating thread.  The flag can be set with
+the :meth:`setDaemon` method and retrieved with the :meth:`isDaemon` method.
+
+There is a "main thread" object; this corresponds to the initial thread of
+control in the Python program.  It is not a daemon thread.
+
+There is the possibility that "dummy thread objects" are created. These are
+thread objects corresponding to "alien threads", which are threads of control
+started outside the threading module, such as directly from C code.  Dummy
+thread objects have limited functionality; they are always considered alive and
+daemonic, and cannot be :meth:`join`\ ed.  They are never deleted, since it is
+impossible to detect the termination of alien threads.
+
+
+.. class:: Thread(group=None, target=None, name=None, args=(), kwargs={})
+
+   This constructor should always be called with keyword arguments.  Arguments are:
+
+   *group* should be ``None``; reserved for future extension when a
+   :class:`ThreadGroup` class is implemented.
+
+   *target* is the callable object to be invoked by the :meth:`run` method.
+   Defaults to ``None``, meaning nothing is called.
+
+   *name* is the thread name.  By default, a unique name is constructed of the form
+   "Thread-*N*" where *N* is a small decimal number.
+
+   *args* is the argument tuple for the target invocation.  Defaults to ``()``.
+
+   *kwargs* is a dictionary of keyword arguments for the target invocation.
+   Defaults to ``{}``.
+
+   If the subclass overrides the constructor, it must make sure to invoke the base
+   class constructor (``Thread.__init__()``) before doing anything else to the
+   thread.
+
+
+.. method:: Thread.start()
+
+   Start the thread's activity.
+
+   It must be called at most once per thread object.  It arranges for the object's
+   :meth:`run` method to be invoked in a separate thread of control.
+
+   This method will raise a :exc:`RuntimeException` if called more than once on the
+   same thread object.
+
+
+.. method:: Thread.run()
+
+   Method representing the thread's activity.
+
+   You may override this method in a subclass.  The standard :meth:`run` method
+   invokes the callable object passed to the object's constructor as the *target*
+   argument, if any, with sequential and keyword arguments taken from the *args*
+   and *kwargs* arguments, respectively.
+
+
+.. method:: Thread.join([timeout])
+
+   Wait until the thread terminates. This blocks the calling thread until the
+   thread whose :meth:`join` method is called terminates -- either normally or
+   through an unhandled exception -- or until the optional timeout occurs.
+
+   When the *timeout* argument is present and not ``None``, it should be a floating
+   point number specifying a timeout for the operation in seconds (or fractions
+   thereof). As :meth:`join` always  returns ``None``, you must call
+   :meth:`isAlive` to decide whether  a timeout happened.
+
+   When the *timeout* argument is not present or ``None``, the operation will block
+   until the thread terminates.
+
+   A thread can be :meth:`join`\ ed many times.
+
+   :meth:`join` may throw a :exc:`RuntimeError`, if an attempt is made to join the
+   current thread as that would cause a deadlock. It is also an error to
+   :meth:`join` a thread before it has been started and attempts to do so raises
+   same exception.
+
+
+.. method:: Thread.getName()
+
+   Return the thread's name.
+
+
+.. method:: Thread.setName(name)
+
+   Set the thread's name.
+
+   The name is a string used for identification purposes only. It has no semantics.
+   Multiple threads may be given the same name.  The initial name is set by the
+   constructor.
+
+
+.. method:: Thread.isAlive()
+
+   Return whether the thread is alive.
+
+   Roughly, a thread is alive from the moment the :meth:`start` method returns
+   until its :meth:`run` method terminates. The module function :func:`enumerate`
+   returns a list of all alive threads.
+
+
+.. method:: Thread.isDaemon()
+
+   Return the thread's daemon flag.
+
+
+.. method:: Thread.setDaemon(daemonic)
+
+   Set the thread's daemon flag to the Boolean value *daemonic*. This must be
+   called before :meth:`start` is called, otherwise :exc:`RuntimeError` is raised.
+
+   The initial value is inherited from the creating thread.
+
+   The entire Python program exits when no alive non-daemon threads are left.
+
+
+.. _timer-objects:
+
+Timer Objects
+-------------
+
+This class represents an action that should be run only after a certain amount
+of time has passed --- a timer.  :class:`Timer` is a subclass of :class:`Thread`
+and as such also functions as an example of creating custom threads.
+
+Timers are started, as with threads, by calling their :meth:`start` method.  The
+timer can be stopped (before its action has begun) by calling the :meth:`cancel`
+method.  The interval the timer will wait before executing its action may not be
+exactly the same as the interval specified by the user.
+
+For example::
+
+   def hello():
+       print "hello, world"
+
+   t = Timer(30.0, hello)
+   t.start() # after 30 seconds, "hello, world" will be printed
+
+
+.. class:: Timer(interval, function, args=[], kwargs={})
+
+   Create a timer that will run *function* with arguments *args* and  keyword
+   arguments *kwargs*, after *interval* seconds have passed.
+
+
+.. method:: Timer.cancel()
+
+   Stop the timer, and cancel the execution of the timer's action.  This will only
+   work if the timer is still in its waiting stage.
+
+
+.. _with-locks:
+
+Using locks, conditions, and semaphores in the :keyword:`with` statement
+------------------------------------------------------------------------
+
+All of the objects provided by this module that have :meth:`acquire` and
+:meth:`release` methods can be used as context managers for a :keyword:`with`
+statement.  The :meth:`acquire` method will be called when the block is entered,
+and :meth:`release` will be called when the block is exited.
+
+Currently, :class:`Lock`, :class:`RLock`, :class:`Condition`,
+:class:`Semaphore`, and :class:`BoundedSemaphore` objects may be used as
+:keyword:`with` statement context managers.  For example::
+
+   from __future__ import with_statement
+   import threading
+
+   some_rlock = threading.RLock()
+
+   with some_rlock:
+       print "some_rlock is locked while this executes"
+
diff --git a/Doc/library/time.rst b/Doc/library/time.rst
new file mode 100644
index 0000000..04c8f66
--- /dev/null
+++ b/Doc/library/time.rst
@@ -0,0 +1,540 @@
+
+:mod:`time` --- Time access and conversions
+===========================================
+
+.. module:: time
+   :synopsis: Time access and conversions.
+
+
+This module provides various time-related functions. For related
+functionality, see also the :mod:`datetime` and :mod:`calendar` modules.
+
+Although this module is always available,
+not all functions are available on all platforms.  Most of the functions
+defined in this module call platform C library functions with the same name.  It
+may sometimes be helpful to consult the platform documentation, because the
+semantics of these functions varies among platforms.
+
+An explanation of some terminology and conventions is in order.
+
+  .. index:: single: epoch
+
+* The :dfn:`epoch` is the point where the time starts.  On January 1st of that
+  year, at 0 hours, the "time since the epoch" is zero.  For Unix, the epoch is
+  1970.  To find out what the epoch is, look at ``gmtime(0)``.
+
+  .. index:: single: Year 2038
+
+* The functions in this module do not handle dates and times before the epoch or
+  far in the future.  The cut-off point in the future is determined by the C
+  library; for Unix, it is typically in 2038.
+
+  .. index::
+     single: Year 2000
+     single: Y2K
+
+* **Year 2000 (Y2K) issues**:  Python depends on the platform's C library, which
+  generally doesn't have year 2000 issues, since all dates and times are
+  represented internally as seconds since the epoch.  Functions accepting a
+  :class:`struct_time` (see below) generally require a 4-digit year.  For backward
+  compatibility, 2-digit years are supported if the module variable
+  ``accept2dyear`` is a non-zero integer; this variable is initialized to ``1``
+  unless the environment variable :envvar:`PYTHONY2K` is set to a non-empty
+  string, in which case it is initialized to ``0``.  Thus, you can set
+  :envvar:`PYTHONY2K` to a non-empty string in the environment to require 4-digit
+  years for all year input.  When 2-digit years are accepted, they are converted
+  according to the POSIX or X/Open standard: values 69-99 are mapped to 1969-1999,
+  and values 0--68 are mapped to 2000--2068. Values 100--1899 are always illegal.
+  Note that this is new as of Python 1.5.2(a2); earlier versions, up to Python
+  1.5.1 and 1.5.2a1, would add 1900 to year values below 1900.
+
+  .. index::
+     single: UTC
+     single: Coordinated Universal Time
+     single: Greenwich Mean Time
+
+* UTC is Coordinated Universal Time (formerly known as Greenwich Mean Time, or
+  GMT).  The acronym UTC is not a mistake but a compromise between English and
+  French.
+
+  .. index:: single: Daylight Saving Time
+
+* DST is Daylight Saving Time, an adjustment of the timezone by (usually) one
+  hour during part of the year.  DST rules are magic (determined by local law) and
+  can change from year to year.  The C library has a table containing the local
+  rules (often it is read from a system file for flexibility) and is the only
+  source of True Wisdom in this respect.
+
+* The precision of the various real-time functions may be less than suggested by
+  the units in which their value or argument is expressed. E.g. on most Unix
+  systems, the clock "ticks" only 50 or 100 times a second, and on the Mac, times
+  are only accurate to whole seconds.
+
+* On the other hand, the precision of :func:`time` and :func:`sleep` is better
+  than their Unix equivalents: times are expressed as floating point numbers,
+  :func:`time` returns the most accurate time available (using Unix
+  :cfunc:`gettimeofday` where available), and :func:`sleep` will accept a time
+  with a nonzero fraction (Unix :cfunc:`select` is used to implement this, where
+  available).
+
+* The time value as returned by :func:`gmtime`, :func:`localtime`, and
+  :func:`strptime`, and accepted by :func:`asctime`, :func:`mktime` and
+  :func:`strftime`, is a sequence of 9 integers.  The return values of
+  :func:`gmtime`, :func:`localtime`, and :func:`strptime` also offer attribute
+  names for individual fields.
+
+  +-------+------------------+------------------------------+
+  | Index | Attribute        | Values                       |
+  +=======+==================+==============================+
+  | 0     | :attr:`tm_year`  | (for example, 1993)          |
+  +-------+------------------+------------------------------+
+  | 1     | :attr:`tm_mon`   | range [1,12]                 |
+  +-------+------------------+------------------------------+
+  | 2     | :attr:`tm_mday`  | range [1,31]                 |
+  +-------+------------------+------------------------------+
+  | 3     | :attr:`tm_hour`  | range [0,23]                 |
+  +-------+------------------+------------------------------+
+  | 4     | :attr:`tm_min`   | range [0,59]                 |
+  +-------+------------------+------------------------------+
+  | 5     | :attr:`tm_sec`   | range [0,61]; see **(1)** in |
+  |       |                  | :func:`strftime` description |
+  +-------+------------------+------------------------------+
+  | 6     | :attr:`tm_wday`  | range [0,6], Monday is 0     |
+  +-------+------------------+------------------------------+
+  | 7     | :attr:`tm_yday`  | range [1,366]                |
+  +-------+------------------+------------------------------+
+  | 8     | :attr:`tm_isdst` | 0, 1 or -1; see below        |
+  +-------+------------------+------------------------------+
+
+  Note that unlike the C structure, the month value is a range of 1-12, not 0-11.
+  A year value will be handled as described under "Year 2000 (Y2K) issues" above.
+  A ``-1`` argument as the daylight savings flag, passed to :func:`mktime` will
+  usually result in the correct daylight savings state to be filled in.
+
+  When a tuple with an incorrect length is passed to a function expecting a
+  :class:`struct_time`, or having elements of the wrong type, a :exc:`TypeError`
+  is raised.
+
+  .. versionchanged:: 2.2
+     The time value sequence was changed from a tuple to a :class:`struct_time`, with
+     the addition of attribute names for the fields.
+
+The module defines the following functions and data items:
+
+
+.. data:: accept2dyear
+
+   Boolean value indicating whether two-digit year values will be accepted.  This
+   is true by default, but will be set to false if the environment variable
+   :envvar:`PYTHONY2K` has been set to a non-empty string.  It may also be modified
+   at run time.
+
+
+.. data:: altzone
+
+   The offset of the local DST timezone, in seconds west of UTC, if one is defined.
+   This is negative if the local DST timezone is east of UTC (as in Western Europe,
+   including the UK).  Only use this if ``daylight`` is nonzero.
+
+
+.. function:: asctime([t])
+
+   Convert a tuple or :class:`struct_time` representing a time as returned by
+   :func:`gmtime` or :func:`localtime` to a 24-character string of the following
+   form: ``'Sun Jun 20 23:21:05 1993'``.  If *t* is not provided, the current time
+   as returned by :func:`localtime` is used. Locale information is not used by
+   :func:`asctime`.
+
+   .. note::
+
+      Unlike the C function of the same name, there is no trailing newline.
+
+   .. versionchanged:: 2.1
+      Allowed *t* to be omitted.
+
+
+.. function:: clock()
+
+   .. index::
+      single: CPU time
+      single: processor time
+      single: benchmarking
+
+   On Unix, return the current processor time as a floating point number expressed
+   in seconds.  The precision, and in fact the very definition of the meaning of
+   "processor time", depends on that of the C function of the same name, but in any
+   case, this is the function to use for benchmarking Python or timing algorithms.
+
+   On Windows, this function returns wall-clock seconds elapsed since the first
+   call to this function, as a floating point number, based on the Win32 function
+   :cfunc:`QueryPerformanceCounter`. The resolution is typically better than one
+   microsecond.
+
+
+.. function:: ctime([secs])
+
+   Convert a time expressed in seconds since the epoch to a string representing
+   local time. If *secs* is not provided or :const:`None`, the current time as
+   returned by :func:`time` is used.  ``ctime(secs)`` is equivalent to
+   ``asctime(localtime(secs))``. Locale information is not used by :func:`ctime`.
+
+   .. versionchanged:: 2.1
+      Allowed *secs* to be omitted.
+
+   .. versionchanged:: 2.4
+      If *secs* is :const:`None`, the current time is used.
+
+
+.. data:: daylight
+
+   Nonzero if a DST timezone is defined.
+
+
+.. function:: gmtime([secs])
+
+   Convert a time expressed in seconds since the epoch to a :class:`struct_time` in
+   UTC in which the dst flag is always zero.  If *secs* is not provided or
+   :const:`None`, the current time as returned by :func:`time` is used.  Fractions
+   of a second are ignored.  See above for a description of the
+   :class:`struct_time` object. See :func:`calendar.timegm` for the inverse of this
+   function.
+
+   .. versionchanged:: 2.1
+      Allowed *secs* to be omitted.
+
+   .. versionchanged:: 2.4
+      If *secs* is :const:`None`, the current time is used.
+
+
+.. function:: localtime([secs])
+
+   Like :func:`gmtime` but converts to local time.  If *secs* is not provided or
+   :const:`None`, the current time as returned by :func:`time` is used.  The dst
+   flag is set to ``1`` when DST applies to the given time.
+
+   .. versionchanged:: 2.1
+      Allowed *secs* to be omitted.
+
+   .. versionchanged:: 2.4
+      If *secs* is :const:`None`, the current time is used.
+
+
+.. function:: mktime(t)
+
+   This is the inverse function of :func:`localtime`.  Its argument is the
+   :class:`struct_time` or full 9-tuple (since the dst flag is needed; use ``-1``
+   as the dst flag if it is unknown) which expresses the time in *local* time, not
+   UTC.  It returns a floating point number, for compatibility with :func:`time`.
+   If the input value cannot be represented as a valid time, either
+   :exc:`OverflowError` or :exc:`ValueError` will be raised (which depends on
+   whether the invalid value is caught by Python or the underlying C libraries).
+   The earliest date for which it can generate a time is platform-dependent.
+
+
+.. function:: sleep(secs)
+
+   Suspend execution for the given number of seconds.  The argument may be a
+   floating point number to indicate a more precise sleep time. The actual
+   suspension time may be less than that requested because any caught signal will
+   terminate the :func:`sleep` following execution of that signal's catching
+   routine.  Also, the suspension time may be longer than requested by an arbitrary
+   amount because of the scheduling of other activity in the system.
+
+
+.. function:: strftime(format[, t])
+
+   Convert a tuple or :class:`struct_time` representing a time as returned by
+   :func:`gmtime` or :func:`localtime` to a string as specified by the *format*
+   argument.  If *t* is not provided, the current time as returned by
+   :func:`localtime` is used.  *format* must be a string.  :exc:`ValueError` is
+   raised if any field in *t* is outside of the allowed range.
+
+   .. versionchanged:: 2.1
+      Allowed *t* to be omitted.
+
+   .. versionchanged:: 2.4
+      :exc:`ValueError` raised if a field in *t* is out of range.
+
+   .. versionchanged:: 2.5
+      0 is now a legal argument for any position in the time tuple; if it is normally
+      illegal the value is forced to a correct one..
+
+   The following directives can be embedded in the *format* string. They are shown
+   without the optional field width and precision specification, and are replaced
+   by the indicated characters in the :func:`strftime` result:
+
+   +-----------+--------------------------------+-------+
+   | Directive | Meaning                        | Notes |
+   +===========+================================+=======+
+   | ``%a``    | Locale's abbreviated weekday   |       |
+   |           | name.                          |       |
+   +-----------+--------------------------------+-------+
+   | ``%A``    | Locale's full weekday name.    |       |
+   +-----------+--------------------------------+-------+
+   | ``%b``    | Locale's abbreviated month     |       |
+   |           | name.                          |       |
+   +-----------+--------------------------------+-------+
+   | ``%B``    | Locale's full month name.      |       |
+   +-----------+--------------------------------+-------+
+   | ``%c``    | Locale's appropriate date and  |       |
+   |           | time representation.           |       |
+   +-----------+--------------------------------+-------+
+   | ``%d``    | Day of the month as a decimal  |       |
+   |           | number [01,31].                |       |
+   +-----------+--------------------------------+-------+
+   | ``%H``    | Hour (24-hour clock) as a      |       |
+   |           | decimal number [00,23].        |       |
+   +-----------+--------------------------------+-------+
+   | ``%I``    | Hour (12-hour clock) as a      |       |
+   |           | decimal number [01,12].        |       |
+   +-----------+--------------------------------+-------+
+   | ``%j``    | Day of the year as a decimal   |       |
+   |           | number [001,366].              |       |
+   +-----------+--------------------------------+-------+
+   | ``%m``    | Month as a decimal number      |       |
+   |           | [01,12].                       |       |
+   +-----------+--------------------------------+-------+
+   | ``%M``    | Minute as a decimal number     |       |
+   |           | [00,59].                       |       |
+   +-----------+--------------------------------+-------+
+   | ``%p``    | Locale's equivalent of either  | \(1)  |
+   |           | AM or PM.                      |       |
+   +-----------+--------------------------------+-------+
+   | ``%S``    | Second as a decimal number     | \(2)  |
+   |           | [00,61].                       |       |
+   +-----------+--------------------------------+-------+
+   | ``%U``    | Week number of the year        | \(3)  |
+   |           | (Sunday as the first day of    |       |
+   |           | the week) as a decimal number  |       |
+   |           | [00,53].  All days in a new    |       |
+   |           | year preceding the first       |       |
+   |           | Sunday are considered to be in |       |
+   |           | week 0.                        |       |
+   +-----------+--------------------------------+-------+
+   | ``%w``    | Weekday as a decimal number    |       |
+   |           | [0(Sunday),6].                 |       |
+   +-----------+--------------------------------+-------+
+   | ``%W``    | Week number of the year        | \(3)  |
+   |           | (Monday as the first day of    |       |
+   |           | the week) as a decimal number  |       |
+   |           | [00,53].  All days in a new    |       |
+   |           | year preceding the first       |       |
+   |           | Monday are considered to be in |       |
+   |           | week 0.                        |       |
+   +-----------+--------------------------------+-------+
+   | ``%x``    | Locale's appropriate date      |       |
+   |           | representation.                |       |
+   +-----------+--------------------------------+-------+
+   | ``%X``    | Locale's appropriate time      |       |
+   |           | representation.                |       |
+   +-----------+--------------------------------+-------+
+   | ``%y``    | Year without century as a      |       |
+   |           | decimal number [00,99].        |       |
+   +-----------+--------------------------------+-------+
+   | ``%Y``    | Year with century as a decimal |       |
+   |           | number.                        |       |
+   +-----------+--------------------------------+-------+
+   | ``%Z``    | Time zone name (no characters  |       |
+   |           | if no time zone exists).       |       |
+   +-----------+--------------------------------+-------+
+   | ``%%``    | A literal ``'%'`` character.   |       |
+   +-----------+--------------------------------+-------+
+
+   Notes:
+
+   (1)
+      When used with the :func:`strptime` function, the ``%p`` directive only affects
+      the output hour field if the ``%I`` directive is used to parse the hour.
+
+   (2)
+      The range really is ``0`` to ``61``; this accounts for leap seconds and the
+      (very rare) double leap seconds.
+
+   (3)
+      When used with the :func:`strptime` function, ``%U`` and ``%W`` are only used in
+      calculations when the day of the week and the year are specified.
+
+   Here is an example, a format for dates compatible with that specified  in the
+   :rfc:`2822` Internet email standard.  [#]_ ::
+
+      >>> from time import gmtime, strftime
+      >>> strftime("%a, %d %b %Y %H:%M:%S +0000", gmtime())
+      'Thu, 28 Jun 2001 14:17:15 +0000'
+
+   Additional directives may be supported on certain platforms, but only the ones
+   listed here have a meaning standardized by ANSI C.
+
+   On some platforms, an optional field width and precision specification can
+   immediately follow the initial ``'%'`` of a directive in the following order;
+   this is also not portable. The field width is normally 2 except for ``%j`` where
+   it is 3.
+
+
+.. function:: strptime(string[, format])
+
+   Parse a string representing a time according to a format.  The return  value is
+   a :class:`struct_time` as returned by :func:`gmtime` or :func:`localtime`.
+
+   The *format* parameter uses the same directives as those used by
+   :func:`strftime`; it defaults to ``"%a %b %d %H:%M:%S %Y"`` which matches the
+   formatting returned by :func:`ctime`. If *string* cannot be parsed according to
+   *format*, or if it has excess data after parsing, :exc:`ValueError` is raised.
+   The default values used to fill in any missing data when more accurate values
+   cannot be inferred are ``(1900, 1, 1, 0, 0, 0, 0, 1, -1)``.
+
+   For example::
+
+      >>> import time
+      >>> time.strptime("30 Nov 00", "%d %b %y")
+      (2000, 11, 30, 0, 0, 0, 3, 335, -1)
+
+   Support for the ``%Z`` directive is based on the values contained in ``tzname``
+   and whether ``daylight`` is true.  Because of this, it is platform-specific
+   except for recognizing UTC and GMT which are always known (and are considered to
+   be non-daylight savings timezones).
+
+   Only the directives specified in the documentation are supported.  Because
+   ``strftime()`` is implemented per platform it can sometimes offer more
+   directives than those listed.  But ``strptime()`` is independent of any platform
+   and thus does not necessarily support all directives available that are not
+   documented as supported.
+
+
+.. data:: struct_time
+
+   The type of the time value sequence returned by :func:`gmtime`,
+   :func:`localtime`, and :func:`strptime`.
+
+   .. versionadded:: 2.2
+
+
+.. function:: time()
+
+   Return the time as a floating point number expressed in seconds since the epoch,
+   in UTC.  Note that even though the time is always returned as a floating point
+   number, not all systems provide time with a better precision than 1 second.
+   While this function normally returns non-decreasing values, it can return a
+   lower value than a previous call if the system clock has been set back between
+   the two calls.
+
+
+.. data:: timezone
+
+   The offset of the local (non-DST) timezone, in seconds west of UTC (negative in
+   most of Western Europe, positive in the US, zero in the UK).
+
+
+.. data:: tzname
+
+   A tuple of two strings: the first is the name of the local non-DST timezone, the
+   second is the name of the local DST timezone.  If no DST timezone is defined,
+   the second string should not be used.
+
+
+.. function:: tzset()
+
+   Resets the time conversion rules used by the library routines. The environment
+   variable :envvar:`TZ` specifies how this is done.
+
+   .. versionadded:: 2.3
+
+   Availability: Unix.
+
+   .. note::
+
+      Although in many cases, changing the :envvar:`TZ` environment variable may
+      affect the output of functions like :func:`localtime` without calling
+      :func:`tzset`, this behavior should not be relied on.
+
+      The :envvar:`TZ` environment variable should contain no whitespace.
+
+   The standard format of the :envvar:`TZ` environment variable is (whitespace
+   added for clarity)::
+
+      std offset [dst [offset [,start[/time], end[/time]]]]
+
+   Where the components are:
+
+   ``std`` and ``dst``
+      Three or more alphanumerics giving the timezone abbreviations. These will be
+      propagated into time.tzname
+
+   ``offset``
+      The offset has the form: ``± hh[:mm[:ss]]``. This indicates the value
+      added the local time to arrive at UTC.  If preceded by a '-', the timezone
+      is east of the Prime Meridian; otherwise, it is west. If no offset follows
+      dst, summer time is assumed to be one hour ahead of standard time.
+
+   ``start[/time], end[/time]``
+      Indicates when to change to and back from DST. The format of the
+      start and end dates are one of the following:
+
+      :samp:`J{n}`
+         The Julian day *n* (1 <= *n* <= 365). Leap days are not counted, so in
+         all years February 28 is day 59 and March 1 is day 60.
+
+      :samp:`{n}`
+         The zero-based Julian day (0 <= *n* <= 365). Leap days are counted, and
+         it is possible to refer to February 29.
+
+      :samp:`M{m}.{n}.{d}`
+         The *d*'th day (0 <= *d* <= 6) or week *n* of month *m* of the year (1
+         <= *n* <= 5, 1 <= *m* <= 12, where week 5 means "the last *d* day in
+         month *m*" which may occur in either the fourth or the fifth
+         week). Week 1 is the first week in which the *d*'th day occurs. Day
+         zero is Sunday.
+
+      ``time`` has the same format as ``offset`` except that no leading sign
+      ('-' or '+') is allowed. The default, if time is not given, is 02:00:00.
+
+   ::
+
+      >>> os.environ['TZ'] = 'EST+05EDT,M4.1.0,M10.5.0'
+      >>> time.tzset()
+      >>> time.strftime('%X %x %Z')
+      '02:07:36 05/08/03 EDT'
+      >>> os.environ['TZ'] = 'AEST-10AEDT-11,M10.5.0,M3.5.0'
+      >>> time.tzset()
+      >>> time.strftime('%X %x %Z')
+      '16:08:12 05/08/03 AEST'
+
+   On many Unix systems (including \*BSD, Linux, Solaris, and Darwin), it is more
+   convenient to use the system's zoneinfo (:manpage:`tzfile(5)`)  database to
+   specify the timezone rules. To do this, set the  :envvar:`TZ` environment
+   variable to the path of the required timezone  datafile, relative to the root of
+   the systems 'zoneinfo' timezone database, usually located at
+   :file:`/usr/share/zoneinfo`. For example,  ``'US/Eastern'``,
+   ``'Australia/Melbourne'``, ``'Egypt'`` or  ``'Europe/Amsterdam'``. ::
+
+      >>> os.environ['TZ'] = 'US/Eastern'
+      >>> time.tzset()
+      >>> time.tzname
+      ('EST', 'EDT')
+      >>> os.environ['TZ'] = 'Egypt'
+      >>> time.tzset()
+      >>> time.tzname
+      ('EET', 'EEST')
+
+
+.. seealso::
+
+   Module :mod:`datetime`
+      More object-oriented interface to dates and times.
+
+   Module :mod:`locale`
+      Internationalization services.  The locale settings can affect the return values
+      for some of  the functions in the :mod:`time` module.
+
+   Module :mod:`calendar`
+      General calendar-related functions.   :func:`timegm` is the inverse of
+      :func:`gmtime` from this module.
+
+.. rubric:: Footnotes
+
+.. [#] The use of ``%Z`` is now deprecated, but the ``%z`` escape that expands to the
+   preferred  hour/minute offset is not supported by all ANSI C libraries. Also, a
+   strict reading of the original 1982 :rfc:`822` standard calls for a two-digit
+   year (%y rather than %Y), but practice moved to 4-digit years long before the
+   year 2000.  The 4-digit year has been mandated by :rfc:`2822`, which obsoletes
+   :rfc:`822`.
+
diff --git a/Doc/library/timeit.rst b/Doc/library/timeit.rst
new file mode 100644
index 0000000..8c0cda3
--- /dev/null
+++ b/Doc/library/timeit.rst
@@ -0,0 +1,243 @@
+
+:mod:`timeit` --- Measure execution time of small code snippets
+===============================================================
+
+.. module:: timeit
+   :synopsis: Measure the execution time of small code snippets.
+
+
+.. versionadded:: 2.3
+
+.. index::
+   single: Benchmarking
+   single: Performance
+
+This module provides a simple way to time small bits of Python code. It has both
+command line as well as callable interfaces.  It avoids a number of common traps
+for measuring execution times.  See also Tim Peters' introduction to the
+"Algorithms" chapter in the Python Cookbook, published by O'Reilly.
+
+The module defines the following public class:
+
+
+.. class:: Timer([stmt='pass' [, setup='pass' [, timer=<timer function>]]])
+
+   Class for timing execution speed of small code snippets.
+
+   The constructor takes a statement to be timed, an additional statement used for
+   setup, and a timer function.  Both statements default to ``'pass'``; the timer
+   function is platform-dependent (see the module doc string).  The statements may
+   contain newlines, as long as they don't contain multi-line string literals.
+
+   To measure the execution time of the first statement, use the :meth:`timeit`
+   method.  The :meth:`repeat` method is a convenience to call :meth:`timeit`
+   multiple times and return a list of results.
+
+   .. versionchanged:: 2.6
+      The *stmt* and *setup* parameters can now also take objects that are callable
+      without arguments. This will embed calls to them in a timer function that will
+      then be executed by :meth:`timeit`.  Note that the timing overhead is a little
+      larger in this case because of the extra function calls.
+
+
+.. method:: Timer.print_exc([file=None])
+
+   Helper to print a traceback from the timed code.
+
+   Typical use::
+
+      t = Timer(...)       # outside the try/except
+      try:
+          t.timeit(...)    # or t.repeat(...)
+      except:
+          t.print_exc()
+
+   The advantage over the standard traceback is that source lines in the compiled
+   template will be displayed. The optional *file* argument directs where the
+   traceback is sent; it defaults to ``sys.stderr``.
+
+
+.. method:: Timer.repeat([repeat=3 [, number=1000000]])
+
+   Call :meth:`timeit` a few times.
+
+   This is a convenience function that calls the :meth:`timeit` repeatedly,
+   returning a list of results.  The first argument specifies how many times to
+   call :meth:`timeit`.  The second argument specifies the *number* argument for
+   :func:`timeit`.
+
+   .. note::
+
+      It's tempting to calculate mean and standard deviation from the result vector
+      and report these.  However, this is not very useful.  In a typical case, the
+      lowest value gives a lower bound for how fast your machine can run the given
+      code snippet; higher values in the result vector are typically not caused by
+      variability in Python's speed, but by other processes interfering with your
+      timing accuracy.  So the :func:`min` of the result is probably the only number
+      you should be interested in.  After that, you should look at the entire vector
+      and apply common sense rather than statistics.
+
+
+.. method:: Timer.timeit([number=1000000])
+
+   Time *number* executions of the main statement. This executes the setup
+   statement once, and then returns the time it takes to execute the main statement
+   a number of times, measured in seconds as a float.  The argument is the number
+   of times through the loop, defaulting to one million.  The main statement, the
+   setup statement and the timer function to be used are passed to the constructor.
+
+   .. note::
+
+      By default, :meth:`timeit` temporarily turns off garbage collection during the
+      timing.  The advantage of this approach is that it makes independent timings
+      more comparable.  This disadvantage is that GC may be an important component of
+      the performance of the function being measured.  If so, GC can be re-enabled as
+      the first statement in the *setup* string.  For example::
+
+         timeit.Timer('for i in range(10): oct(i)', 'gc.enable()').timeit()
+
+Starting with version 2.6, the module also defines two convenience functions:
+
+
+.. function:: repeat(stmt[, setup[, timer[, repeat=3 [, number=1000000]]]])
+
+   Create a :class:`Timer` instance with the given statement, setup code and timer
+   function and run its :meth:`repeat` method with the given repeat count and
+   *number* executions.
+
+   .. versionadded:: 2.6
+
+
+.. function:: timeit(stmt[, setup[, timer[, number=1000000]]])
+
+   Create a :class:`Timer` instance with the given statement, setup code and timer
+   function and run its :meth:`timeit` method with *number* executions.
+
+   .. versionadded:: 2.6
+
+
+Command Line Interface
+----------------------
+
+When called as a program from the command line, the following form is used::
+
+   python -m timeit [-n N] [-r N] [-s S] [-t] [-c] [-h] [statement ...]
+
+where the following options are understood:
+
+-n N/:option:`--number=N`
+   how many times to execute 'statement'
+
+-r N/:option:`--repeat=N`
+   how many times to repeat the timer (default 3)
+
+-s S/:option:`--setup=S`
+   statement to be executed once initially (default ``'pass'``)
+
+-t/:option:`--time`
+   use :func:`time.time` (default on all platforms but Windows)
+
+-c/:option:`--clock`
+   use :func:`time.clock` (default on Windows)
+
+-v/:option:`--verbose`
+   print raw timing results; repeat for more digits precision
+
+-h/:option:`--help`
+   print a short usage message and exit
+
+A multi-line statement may be given by specifying each line as a separate
+statement argument; indented lines are possible by enclosing an argument in
+quotes and using leading spaces.  Multiple :option:`-s` options are treated
+similarly.
+
+If :option:`-n` is not given, a suitable number of loops is calculated by trying
+successive powers of 10 until the total time is at least 0.2 seconds.
+
+The default timer function is platform dependent.  On Windows,
+:func:`time.clock` has microsecond granularity but :func:`time.time`'s
+granularity is 1/60th of a second; on Unix, :func:`time.clock` has 1/100th of a
+second granularity and :func:`time.time` is much more precise.  On either
+platform, the default timer functions measure wall clock time, not the CPU time.
+This means that other processes running on the same computer may interfere with
+the timing.  The best thing to do when accurate timing is necessary is to repeat
+the timing a few times and use the best time.  The :option:`-r` option is good
+for this; the default of 3 repetitions is probably enough in most cases.  On
+Unix, you can use :func:`time.clock` to measure CPU time.
+
+.. note::
+
+   There is a certain baseline overhead associated with executing a pass statement.
+   The code here doesn't try to hide it, but you should be aware of it.  The
+   baseline overhead can be measured by invoking the program without arguments.
+
+The baseline overhead differs between Python versions!  Also, to fairly compare
+older Python versions to Python 2.3, you may want to use Python's :option:`-O`
+option for the older versions to avoid timing ``SET_LINENO`` instructions.
+
+
+Examples
+--------
+
+Here are two example sessions (one using the command line, one using the module
+interface) that compare the cost of using :func:`hasattr` vs.
+:keyword:`try`/:keyword:`except` to test for missing and present object
+attributes. ::
+
+   % timeit.py 'try:' '  str.__bool__' 'except AttributeError:' '  pass'
+   100000 loops, best of 3: 15.7 usec per loop
+   % timeit.py 'if hasattr(str, "__bool__"): pass'
+   100000 loops, best of 3: 4.26 usec per loop
+   % timeit.py 'try:' '  int.__bool__' 'except AttributeError:' '  pass'
+   1000000 loops, best of 3: 1.43 usec per loop
+   % timeit.py 'if hasattr(int, "__bool__"): pass'
+   100000 loops, best of 3: 2.23 usec per loop
+
+::
+
+   >>> import timeit
+   >>> s = """\
+   ... try:
+   ...     str.__bool__
+   ... except AttributeError:
+   ...     pass
+   ... """
+   >>> t = timeit.Timer(stmt=s)
+   >>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
+   17.09 usec/pass
+   >>> s = """\
+   ... if hasattr(str, '__bool__'): pass
+   ... """
+   >>> t = timeit.Timer(stmt=s)
+   >>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
+   4.85 usec/pass
+   >>> s = """\
+   ... try:
+   ...     int.__bool__
+   ... except AttributeError:
+   ...     pass
+   ... """
+   >>> t = timeit.Timer(stmt=s)
+   >>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
+   1.97 usec/pass
+   >>> s = """\
+   ... if hasattr(int, '__bool__'): pass
+   ... """
+   >>> t = timeit.Timer(stmt=s)
+   >>> print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
+   3.15 usec/pass
+
+To give the :mod:`timeit` module access to functions you define, you can pass a
+``setup`` parameter which contains an import statement::
+
+   def test():
+       "Stupid test function"
+       L = []
+       for i in range(100):
+           L.append(i)
+
+   if __name__=='__main__':
+       from timeit import Timer
+       t = Timer("test()", "from __main__ import test")
+       print t.timeit()
+
diff --git a/Doc/library/tix.rst b/Doc/library/tix.rst
new file mode 100644
index 0000000..4701c15
--- /dev/null
+++ b/Doc/library/tix.rst
@@ -0,0 +1,602 @@
+:mod:`Tix` --- Extension widgets for Tk
+=======================================
+
+.. module:: Tix
+   :synopsis: Tk Extension Widgets for Tkinter
+.. sectionauthor:: Mike Clarkson <mikeclarkson@users.sourceforge.net>
+
+
+.. index:: single: Tix
+
+The :mod:`Tix` (Tk Interface Extension) module provides an additional rich set
+of widgets. Although the standard Tk library has many useful widgets, they are
+far from complete. The :mod:`Tix` library provides most of the commonly needed
+widgets that are missing from standard Tk: :class:`HList`, :class:`ComboBox`,
+:class:`Control` (a.k.a. SpinBox) and an assortment of scrollable widgets.
+:mod:`Tix` also includes many more widgets that are generally useful in a wide
+range of applications: :class:`NoteBook`, :class:`FileEntry`,
+:class:`PanedWindow`, etc; there are more than 40 of them.
+
+With all these new widgets, you can introduce new interaction techniques into
+applications, creating more useful and more intuitive user interfaces. You can
+design your application by choosing the most appropriate widgets to match the
+special needs of your application and users.
+
+
+.. seealso::
+
+   `Tix Homepage <http://tix.sourceforge.net/>`_
+      The home page for :mod:`Tix`.  This includes links to additional documentation
+      and downloads.
+
+   `Tix Man Pages <http://tix.sourceforge.net/dist/current/man/>`_
+      On-line version of the man pages and reference material.
+
+   `Tix Programming Guide <http://tix.sourceforge.net/dist/current/docs/tix-book/tix.book.html>`_
+      On-line version of the programmer's reference material.
+
+   `Tix Development Applications <http://tix.sourceforge.net/Tide/>`_
+      Tix applications for development of Tix and Tkinter programs. Tide applications
+      work under Tk or Tkinter, and include :program:`TixInspect`, an inspector to
+      remotely modify and debug Tix/Tk/Tkinter applications.
+
+
+Using Tix
+---------
+
+
+.. class:: Tix(screenName[, baseName[, className]])
+
+   Toplevel widget of Tix which represents mostly the main window of an
+   application. It has an associated Tcl interpreter.
+
+   Classes in the :mod:`Tix` module subclasses the classes in the :mod:`Tkinter`
+   module. The former imports the latter, so to use :mod:`Tix` with Tkinter, all
+   you need to do is to import one module. In general, you can just import
+   :mod:`Tix`, and replace the toplevel call to :class:`Tkinter.Tk` with
+   :class:`Tix.Tk`::
+
+      import Tix
+      from Tkconstants import *
+      root = Tix.Tk()
+
+To use :mod:`Tix`, you must have the :mod:`Tix` widgets installed, usually
+alongside your installation of the Tk widgets. To test your installation, try
+the following::
+
+   import Tix
+   root = Tix.Tk()
+   root.tk.eval('package require Tix')
+
+If this fails, you have a Tk installation problem which must be resolved before
+proceeding. Use the environment variable :envvar:`TIX_LIBRARY` to point to the
+installed :mod:`Tix` library directory, and make sure you have the dynamic
+object library (:file:`tix8183.dll` or :file:`libtix8183.so`) in  the same
+directory that contains your Tk dynamic object library (:file:`tk8183.dll` or
+:file:`libtk8183.so`). The directory with the dynamic object library should also
+have a file called :file:`pkgIndex.tcl` (case sensitive), which contains the
+line::
+
+   package ifneeded Tix 8.1 [list load "[file join $dir tix8183.dll]" Tix]
+
+.. % $ <-- bow to font-lock
+
+
+Tix Widgets
+-----------
+
+`Tix <http://tix.sourceforge.net/dist/current/man/html/TixCmd/TixIntro.htm>`_
+introduces over 40 widget classes to the :mod:`Tkinter`  repertoire.  There is a
+demo of all the :mod:`Tix` widgets in the :file:`Demo/tix` directory of the
+standard distribution.
+
+.. % The Python sample code is still being added to Python, hence commented out
+
+
+Basic Widgets
+^^^^^^^^^^^^^
+
+
+.. class:: Balloon()
+
+   A `Balloon
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixBalloon.htm>`_ that
+   pops up over a widget to provide help.  When the user moves the cursor inside a
+   widget to which a Balloon widget has been bound, a small pop-up window with a
+   descriptive message will be shown on the screen.
+
+.. % Python Demo of:
+.. % \ulink{Balloon}{http://tix.sourceforge.net/dist/current/demos/samples/Balloon.tcl}
+
+
+.. class:: ButtonBox()
+
+   The `ButtonBox
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixButtonBox.htm>`_
+   widget creates a box of buttons, such as is commonly used for ``Ok Cancel``.
+
+.. % Python Demo of:
+.. % \ulink{ButtonBox}{http://tix.sourceforge.net/dist/current/demos/samples/BtnBox.tcl}
+
+
+.. class:: ComboBox()
+
+   The `ComboBox
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixComboBox.htm>`_
+   widget is similar to the combo box control in MS Windows. The user can select a
+   choice by either typing in the entry subwdget or selecting from the listbox
+   subwidget.
+
+.. % Python Demo of:
+.. % \ulink{ComboBox}{http://tix.sourceforge.net/dist/current/demos/samples/ComboBox.tcl}
+
+
+.. class:: Control()
+
+   The `Control
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixControl.htm>`_
+   widget is also known as the :class:`SpinBox` widget. The user can adjust the
+   value by pressing the two arrow buttons or by entering the value directly into
+   the entry. The new value will be checked against the user-defined upper and
+   lower limits.
+
+.. % Python Demo of:
+.. % \ulink{Control}{http://tix.sourceforge.net/dist/current/demos/samples/Control.tcl}
+
+
+.. class:: LabelEntry()
+
+   The `LabelEntry
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixLabelEntry.htm>`_
+   widget packages an entry widget and a label into one mega widget. It can be used
+   be used to simplify the creation of "entry-form" type of interface.
+
+.. % Python Demo of:
+.. % \ulink{LabelEntry}{http://tix.sourceforge.net/dist/current/demos/samples/LabEntry.tcl}
+
+
+.. class:: LabelFrame()
+
+   The `LabelFrame
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixLabelFrame.htm>`_
+   widget packages a frame widget and a label into one mega widget.  To create
+   widgets inside a LabelFrame widget, one creates the new widgets relative to the
+   :attr:`frame` subwidget and manage them inside the :attr:`frame` subwidget.
+
+.. % Python Demo of:
+.. % \ulink{LabelFrame}{http://tix.sourceforge.net/dist/current/demos/samples/LabFrame.tcl}
+
+
+.. class:: Meter()
+
+   The `Meter
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixMeter.htm>`_ widget
+   can be used to show the progress of a background job which may take a long time
+   to execute.
+
+.. % Python Demo of:
+.. % \ulink{Meter}{http://tix.sourceforge.net/dist/current/demos/samples/Meter.tcl}
+
+
+.. class:: OptionMenu()
+
+   The `OptionMenu
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixOptionMenu.htm>`_
+   creates a menu button of options.
+
+.. % Python Demo of:
+.. % \ulink{OptionMenu}{http://tix.sourceforge.net/dist/current/demos/samples/OptMenu.tcl}
+
+
+.. class:: PopupMenu()
+
+   The `PopupMenu
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixPopupMenu.htm>`_
+   widget can be used as a replacement of the ``tk_popup`` command. The advantage
+   of the :mod:`Tix` :class:`PopupMenu` widget is it requires less application code
+   to manipulate.
+
+.. % Python Demo of:
+.. % \ulink{PopupMenu}{http://tix.sourceforge.net/dist/current/demos/samples/PopMenu.tcl}
+
+
+.. class:: Select()
+
+   The `Select
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixSelect.htm>`_ widget
+   is a container of button subwidgets. It can be used to provide radio-box or
+   check-box style of selection options for the user.
+
+.. % Python Demo of:
+.. % \ulink{Select}{http://tix.sourceforge.net/dist/current/demos/samples/Select.tcl}
+
+
+.. class:: StdButtonBox()
+
+   The `StdButtonBox
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixStdButtonBox.htm>`_
+   widget is a group of standard buttons for Motif-like dialog boxes.
+
+.. % Python Demo of:
+.. % \ulink{StdButtonBox}{http://tix.sourceforge.net/dist/current/demos/samples/StdBBox.tcl}
+
+
+File Selectors
+^^^^^^^^^^^^^^
+
+
+.. class:: DirList()
+
+   The `DirList
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixDirList.htm>`_
+   widget displays a list view of a directory, its previous directories and its
+   sub-directories. The user can choose one of the directories displayed in the
+   list or change to another directory.
+
+.. % Python Demo of:
+.. % \ulink{DirList}{http://tix.sourceforge.net/dist/current/demos/samples/DirList.tcl}
+
+
+.. class:: DirTree()
+
+   The `DirTree
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixDirTree.htm>`_
+   widget displays a tree view of a directory, its previous directories and its
+   sub-directories. The user can choose one of the directories displayed in the
+   list or change to another directory.
+
+.. % Python Demo of:
+.. % \ulink{DirTree}{http://tix.sourceforge.net/dist/current/demos/samples/DirTree.tcl}
+
+
+.. class:: DirSelectDialog()
+
+   The `DirSelectDialog
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixDirSelectDialog.htm>`_
+   widget presents the directories in the file system in a dialog window.  The user
+   can use this dialog window to navigate through the file system to select the
+   desired directory.
+
+.. % Python Demo of:
+.. % \ulink{DirSelectDialog}{http://tix.sourceforge.net/dist/current/demos/samples/DirDlg.tcl}
+
+
+.. class:: DirSelectBox()
+
+   The :class:`DirSelectBox` is similar to the standard Motif(TM)
+   directory-selection box. It is generally used for the user to choose a
+   directory.  DirSelectBox stores the directories mostly recently selected into
+   a ComboBox widget so that they can be quickly selected again.
+
+
+.. class:: ExFileSelectBox()
+
+   The `ExFileSelectBox
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixExFileSelectBox.htm>`_
+   widget is usually embedded in a tixExFileSelectDialog widget. It provides an
+   convenient method for the user to select files. The style of the
+   :class:`ExFileSelectBox` widget is very similar to the standard file dialog on
+   MS Windows 3.1.
+
+.. % Python Demo of:
+.. % \ulink{ExFileSelectDialog}{http://tix.sourceforge.net/dist/current/demos/samples/EFileDlg.tcl}
+
+
+.. class:: FileSelectBox()
+
+   The `FileSelectBox
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixFileSelectBox.htm>`_
+   is similar to the standard Motif(TM) file-selection box. It is generally used
+   for the user to choose a file. FileSelectBox stores the files mostly recently
+   selected into a :class:`ComboBox` widget so that they can be quickly selected
+   again.
+
+.. % Python Demo of:
+.. % \ulink{FileSelectDialog}{http://tix.sourceforge.net/dist/current/demos/samples/FileDlg.tcl}
+
+
+.. class:: FileEntry()
+
+   The `FileEntry
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixFileEntry.htm>`_
+   widget can be used to input a filename. The user can type in the filename
+   manually. Alternatively, the user can press the button widget that sits next to
+   the entry, which will bring up a file selection dialog.
+
+.. % Python Demo of:
+.. % \ulink{FileEntry}{http://tix.sourceforge.net/dist/current/demos/samples/FileEnt.tcl}
+
+
+Hierachical ListBox
+^^^^^^^^^^^^^^^^^^^
+
+
+.. class:: HList()
+
+   The `HList
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixHList.htm>`_ widget
+   can be used to display any data that have a hierarchical structure, for example,
+   file system directory trees. The list entries are indented and connected by
+   branch lines according to their places in the hierarchy.
+
+.. % Python Demo of:
+.. % \ulink{HList}{http://tix.sourceforge.net/dist/current/demos/samples/HList1.tcl}
+
+
+.. class:: CheckList()
+
+   The `CheckList
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixCheckList.htm>`_
+   widget displays a list of items to be selected by the user. CheckList acts
+   similarly to the Tk checkbutton or radiobutton widgets, except it is capable of
+   handling many more items than checkbuttons or radiobuttons.
+
+.. % Python Demo of:
+.. % \ulink{ CheckList}{http://tix.sourceforge.net/dist/current/demos/samples/ChkList.tcl}
+.. % Python Demo of:
+.. % \ulink{ScrolledHList (1)}{http://tix.sourceforge.net/dist/current/demos/samples/SHList.tcl}
+.. % Python Demo of:
+.. % \ulink{ScrolledHList (2)}{http://tix.sourceforge.net/dist/current/demos/samples/SHList2.tcl}
+
+
+.. class:: Tree()
+
+   The `Tree
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixTree.htm>`_ widget
+   can be used to display hierarchical data in a tree form. The user can adjust the
+   view of the tree by opening or closing parts of the tree.
+
+.. % Python Demo of:
+.. % \ulink{Tree}{http://tix.sourceforge.net/dist/current/demos/samples/Tree.tcl}
+.. % Python Demo of:
+.. % \ulink{Tree (Dynamic)}{http://tix.sourceforge.net/dist/current/demos/samples/DynTree.tcl}
+
+
+Tabular ListBox
+^^^^^^^^^^^^^^^
+
+
+.. class:: TList()
+
+   The `TList
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixTList.htm>`_ widget
+   can be used to display data in a tabular format. The list entries of a
+   :class:`TList` widget are similar to the entries in the Tk listbox widget.  The
+   main differences are (1) the :class:`TList` widget can display the list entries
+   in a two dimensional format and (2) you can use graphical images as well as
+   multiple colors and fonts for the list entries.
+
+.. % Python Demo of:
+.. % \ulink{ScrolledTList (1)}{http://tix.sourceforge.net/dist/current/demos/samples/STList1.tcl}
+.. % Python Demo of:
+.. % \ulink{ScrolledTList (2)}{http://tix.sourceforge.net/dist/current/demos/samples/STList2.tcl}
+.. % Grid has yet to be added to Python
+.. % \subsubsection{Grid Widget}
+.. % Python Demo of:
+.. % \ulink{Simple Grid}{http://tix.sourceforge.net/dist/current/demos/samples/SGrid0.tcl}
+.. % Python Demo of:
+.. % \ulink{ScrolledGrid}{http://tix.sourceforge.net/dist/current/demos/samples/SGrid1.tcl}
+.. % Python Demo of:
+.. % \ulink{Editable Grid}{http://tix.sourceforge.net/dist/current/demos/samples/EditGrid.tcl}
+
+
+Manager Widgets
+^^^^^^^^^^^^^^^
+
+
+.. class:: PanedWindow()
+
+   The `PanedWindow
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixPanedWindow.htm>`_
+   widget allows the user to interactively manipulate the sizes of several panes.
+   The panes can be arranged either vertically or horizontally.  The user changes
+   the sizes of the panes by dragging the resize handle between two panes.
+
+.. % Python Demo of:
+.. % \ulink{PanedWindow}{http://tix.sourceforge.net/dist/current/demos/samples/PanedWin.tcl}
+
+
+.. class:: ListNoteBook()
+
+   The `ListNoteBook
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixListNoteBook.htm>`_
+   widget is very similar to the :class:`TixNoteBook` widget: it can be used to
+   display many windows in a limited space using a notebook metaphor. The notebook
+   is divided into a stack of pages (windows). At one time only one of these pages
+   can be shown. The user can navigate through these pages by choosing the name of
+   the desired page in the :attr:`hlist` subwidget.
+
+.. % Python Demo of:
+.. % \ulink{ListNoteBook}{http://tix.sourceforge.net/dist/current/demos/samples/ListNBK.tcl}
+
+
+.. class:: NoteBook()
+
+   The `NoteBook
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixNoteBook.htm>`_
+   widget can be used to display many windows in a limited space using a notebook
+   metaphor. The notebook is divided into a stack of pages. At one time only one of
+   these pages can be shown. The user can navigate through these pages by choosing
+   the visual "tabs" at the top of the NoteBook widget.
+
+.. % Python Demo of:
+.. % \ulink{NoteBook}{http://tix.sourceforge.net/dist/current/demos/samples/NoteBook.tcl}
+
+.. % \subsubsection{Scrolled Widgets}
+.. % Python Demo of:
+.. % \ulink{ScrolledListBox}{http://tix.sourceforge.net/dist/current/demos/samples/SListBox.tcl}
+.. % Python Demo of:
+.. % \ulink{ScrolledText}{http://tix.sourceforge.net/dist/current/demos/samples/SText.tcl}
+.. % Python Demo of:
+.. % \ulink{ScrolledWindow}{http://tix.sourceforge.net/dist/current/demos/samples/SWindow.tcl}
+.. % Python Demo of:
+.. % \ulink{Canvas Object View}{http://tix.sourceforge.net/dist/current/demos/samples/CObjView.tcl}
+
+
+Image Types
+^^^^^^^^^^^
+
+The :mod:`Tix` module adds:
+
+* `pixmap <http://tix.sourceforge.net/dist/current/man/html/TixCmd/pixmap.htm>`_
+  capabilities to all :mod:`Tix` and :mod:`Tkinter` widgets to create color images
+  from XPM files.
+
+  .. % Python Demo of:
+  .. % \ulink{XPM Image In Button}{http://tix.sourceforge.net/dist/current/demos/samples/Xpm.tcl}
+  .. % Python Demo of:
+  .. % \ulink{XPM Image In Menu}{http://tix.sourceforge.net/dist/current/demos/samples/Xpm1.tcl}
+
+* `Compound
+  <http://tix.sourceforge.net/dist/current/man/html/TixCmd/compound.htm>`_ image
+  types can be used to create images that consists of multiple horizontal lines;
+  each line is composed of a series of items (texts, bitmaps, images or spaces)
+  arranged from left to right. For example, a compound image can be used to
+  display a bitmap and a text string simultaneously in a Tk :class:`Button`
+  widget.
+
+  .. % Python Demo of:
+  .. % \ulink{Compound Image In Buttons}{http://tix.sourceforge.net/dist/current/demos/samples/CmpImg.tcl}
+  .. % Python Demo of:
+  .. % \ulink{Compound Image In NoteBook}{http://tix.sourceforge.net/dist/current/demos/samples/CmpImg2.tcl}
+  .. % Python Demo of:
+  .. % \ulink{Compound Image Notebook Color Tabs}{http://tix.sourceforge.net/dist/current/demos/samples/CmpImg4.tcl}
+  .. % Python Demo of:
+  .. % \ulink{Compound Image Icons}{http://tix.sourceforge.net/dist/current/demos/samples/CmpImg3.tcl}
+
+
+Miscellaneous Widgets
+^^^^^^^^^^^^^^^^^^^^^
+
+
+.. class:: InputOnly()
+
+   The `InputOnly
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixInputOnly.htm>`_
+   widgets are to accept inputs from the user, which can be done with the ``bind``
+   command (Unix only).
+
+
+Form Geometry Manager
+^^^^^^^^^^^^^^^^^^^^^
+
+In addition, :mod:`Tix` augments :mod:`Tkinter` by providing:
+
+
+.. class:: Form()
+
+   The `Form
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tixForm.htm>`_ geometry
+   manager based on attachment rules for all Tk widgets.
+
+.. % begin{latexonly}
+.. % \subsection{Tix Class Structure}
+.. % 
+.. % \begin{figure}[hbtp]
+.. % \centerline{\epsfig{file=hierarchy.png,width=.9\textwidth}}
+.. % \vspace{.5cm}
+.. % \caption{The Class Hierarchy of Tix Widgets}
+.. % \end{figure}
+.. % end{latexonly}
+
+
+Tix Commands
+------------
+
+
+.. class:: tixCommand()
+
+   The `tix commands
+   <http://tix.sourceforge.net/dist/current/man/html/TixCmd/tix.htm>`_ provide
+   access to miscellaneous elements of :mod:`Tix`'s internal state and the
+   :mod:`Tix` application context.  Most of the information manipulated by these
+   methods pertains to the application as a whole, or to a screen or display,
+   rather than to a particular window.
+
+   To view the current settings, the common usage is::
+
+      import Tix
+      root = Tix.Tk()
+      print root.tix_configure()
+
+
+.. method:: tixCommand.tix_configure([cnf,] **kw)
+
+   Query or modify the configuration options of the Tix application context. If no
+   option is specified, returns a dictionary all of the available options.  If
+   option is specified with no value, then the method returns a list describing the
+   one named option (this list will be identical to the corresponding sublist of
+   the value returned if no option is specified).  If one or more option-value
+   pairs are specified, then the method modifies the given option(s) to have the
+   given value(s); in this case the method returns an empty string. Option may be
+   any of the configuration options.
+
+
+.. method:: tixCommand.tix_cget(option)
+
+   Returns the current value of the configuration option given by *option*. Option
+   may be any of the configuration options.
+
+
+.. method:: tixCommand.tix_getbitmap(name)
+
+   Locates a bitmap file of the name ``name.xpm`` or ``name`` in one of the bitmap
+   directories (see the :meth:`tix_addbitmapdir` method).  By using
+   :meth:`tix_getbitmap`, you can avoid hard coding the pathnames of the bitmap
+   files in your application. When successful, it returns the complete pathname of
+   the bitmap file, prefixed with the character ``@``.  The returned value can be
+   used to configure the ``bitmap`` option of the Tk and Tix widgets.
+
+
+.. method:: tixCommand.tix_addbitmapdir(directory)
+
+   Tix maintains a list of directories under which the :meth:`tix_getimage` and
+   :meth:`tix_getbitmap` methods will search for image files.  The standard bitmap
+   directory is :file:`$TIX_LIBRARY/bitmaps`. The :meth:`tix_addbitmapdir` method
+   adds *directory* into this list. By using this method, the image files of an
+   applications can also be located using the :meth:`tix_getimage` or
+   :meth:`tix_getbitmap` method.
+
+
+.. method:: tixCommand.tix_filedialog([dlgclass])
+
+   Returns the file selection dialog that may be shared among different calls from
+   this application.  This method will create a file selection dialog widget when
+   it is called the first time. This dialog will be returned by all subsequent
+   calls to :meth:`tix_filedialog`.  An optional dlgclass parameter can be passed
+   as a string to specified what type of file selection dialog widget is desired.
+   Possible options are ``tix``, ``FileSelectDialog`` or ``tixExFileSelectDialog``.
+
+
+.. method:: tixCommand.tix_getimage(self, name)
+
+   Locates an image file of the name :file:`name.xpm`, :file:`name.xbm` or
+   :file:`name.ppm` in one of the bitmap directories (see the
+   :meth:`tix_addbitmapdir` method above). If more than one file with the same name
+   (but different extensions) exist, then the image type is chosen according to the
+   depth of the X display: xbm images are chosen on monochrome displays and color
+   images are chosen on color displays. By using :meth:`tix_getimage`, you can
+   avoid hard coding the pathnames of the image files in your application. When
+   successful, this method returns the name of the newly created image, which can
+   be used to configure the ``image`` option of the Tk and Tix widgets.
+
+
+.. method:: tixCommand.tix_option_get(name)
+
+   Gets the options maintained by the Tix scheme mechanism.
+
+
+.. method:: tixCommand.tix_resetoptions(newScheme, newFontSet[, newScmPrio])
+
+   Resets the scheme and fontset of the Tix application to *newScheme* and
+   *newFontSet*, respectively.  This affects only those widgets created after this
+   call.  Therefore, it is best to call the resetoptions method before the creation
+   of any widgets in a Tix application.
+
+   The optional parameter *newScmPrio* can be given to reset the priority level of
+   the Tk options set by the Tix schemes.
+
+   Because of the way Tk handles the X option database, after Tix has been has
+   imported and inited, it is not possible to reset the color schemes and font sets
+   using the :meth:`tix_config` method. Instead, the :meth:`tix_resetoptions`
+   method must be used.
diff --git a/Doc/library/tk.rst b/Doc/library/tk.rst
new file mode 100644
index 0000000..bb852d2
--- /dev/null
+++ b/Doc/library/tk.rst
@@ -0,0 +1,43 @@
+.. _tkinter:
+
+*********************************
+Graphical User Interfaces with Tk
+*********************************
+
+.. index::
+   single: GUI
+   single: Graphical User Interface
+   single: Tkinter
+   single: Tk
+
+Tk/Tcl has long been an integral part of Python.  It provides a robust and
+platform independent windowing toolkit, that is available to Python programmers
+using the :mod:`Tkinter` module, and its extension, the :mod:`Tix` module.
+
+The :mod:`Tkinter` module is a thin object-oriented layer on top of Tcl/Tk. To
+use :mod:`Tkinter`, you don't need to write Tcl code, but you will need to
+consult the Tk documentation, and occasionally the Tcl documentation.
+:mod:`Tkinter` is a set of wrappers that implement the Tk widgets as Python
+classes.  In addition, the internal module :mod:`_tkinter` provides a threadsafe
+mechanism which allows Python and Tcl to interact.
+
+:mod:`Tkinter`'s chief virtues are that it is fast, and that it usually comes
+bundled with Python. Although it has been used to create some very good
+applications, including IDLE, it has weak documentation and an outdated look and
+feel. For more modern, better documented, and much more extensive GUI
+libraries, see the :ref:`other-gui-packages` section.
+
+.. toctree::
+   
+   tkinter.rst
+   tix.rst
+   scrolledtext.rst
+   turtle.rst
+   idle.rst
+   othergui.rst
+
+.. % Other sections I have in mind are
+.. % Tkinter internals
+.. % Freezing Tkinter applications
+
+
diff --git a/Doc/library/tkinter.rst b/Doc/library/tkinter.rst
new file mode 100644
index 0000000..d52c1e0
--- /dev/null
+++ b/Doc/library/tkinter.rst
@@ -0,0 +1,840 @@
+:mod:`Tkinter` --- Python interface to Tcl/Tk
+=============================================
+
+.. module:: Tkinter
+   :synopsis: Interface to Tcl/Tk for graphical user interfaces
+.. moduleauthor:: Guido van Rossum <guido@Python.org>
+
+
+The :mod:`Tkinter` module ("Tk interface") is the standard Python interface to
+the Tk GUI toolkit.  Both Tk and :mod:`Tkinter` are available on most Unix
+platforms, as well as on Windows and Macintosh systems.  (Tk itself is not part
+of Python; it is maintained at ActiveState.)
+
+
+.. seealso::
+
+   `Python Tkinter Resources <http://www.python.org/topics/tkinter/>`_
+      The Python Tkinter Topic Guide provides a great deal of information on using Tk
+      from Python and links to other sources of information on Tk.
+
+   `An Introduction to Tkinter <http://www.pythonware.com/library/an-introduction-to-tkinter.htm>`_
+      Fredrik Lundh's on-line reference material.
+
+   `Tkinter reference: a GUI for Python <http://www.nmt.edu/tcc/help/pubs/lang.html>`_
+      On-line reference material.
+
+   `Tkinter for JPython <http://jtkinter.sourceforge.net>`_
+      The Jython interface to Tkinter.
+
+   `Python and Tkinter Programming <http://www.amazon.com/exec/obidos/ASIN/1884777813>`_
+      The book by John Grayson (ISBN 1-884777-81-3).
+
+
+Tkinter Modules
+---------------
+
+Most of the time, the :mod:`Tkinter` module is all you really need, but a number
+of additional modules are available as well.  The Tk interface is located in a
+binary module named :mod:`_tkinter`. This module contains the low-level
+interface to Tk, and should never be used directly by application programmers.
+It is usually a shared library (or DLL), but might in some cases be statically
+linked with the Python interpreter.
+
+In addition to the Tk interface module, :mod:`Tkinter` includes a number of
+Python modules. The two most important modules are the :mod:`Tkinter` module
+itself, and a module called :mod:`Tkconstants`. The former automatically imports
+the latter, so to use Tkinter, all you need to do is to import one module::
+
+   import Tkinter
+
+Or, more often::
+
+   from Tkinter import *
+
+
+.. class:: Tk(screenName=None, baseName=None, className='Tk', useTk=1)
+
+   The :class:`Tk` class is instantiated without arguments. This creates a toplevel
+   widget of Tk which usually is the main window of an application. Each instance
+   has its own associated Tcl interpreter.
+
+   .. % FIXME: The following keyword arguments are currently recognized:
+
+   .. versionchanged:: 2.4
+      The *useTk* parameter was added.
+
+
+.. function:: Tcl(screenName=None, baseName=None, className='Tk', useTk=0)
+
+   The :func:`Tcl` function is a factory function which creates an object much like
+   that created by the :class:`Tk` class, except that it does not initialize the Tk
+   subsystem.  This is most often useful when driving the Tcl interpreter in an
+   environment where one doesn't want to create extraneous toplevel windows, or
+   where one cannot (such as Unix/Linux systems without an X server).  An object
+   created by the :func:`Tcl` object can have a Toplevel window created (and the Tk
+   subsystem initialized) by calling its :meth:`loadtk` method.
+
+   .. versionadded:: 2.4
+
+Other modules that provide Tk support include:
+
+:mod:`ScrolledText`
+   Text widget with a vertical scroll bar built in.
+
+:mod:`tkColorChooser`
+   Dialog to let the user choose a color.
+
+:mod:`tkCommonDialog`
+   Base class for the dialogs defined in the other modules listed here.
+
+:mod:`tkFileDialog`
+   Common dialogs to allow the user to specify a file to open or save.
+
+:mod:`tkFont`
+   Utilities to help work with fonts.
+
+:mod:`tkMessageBox`
+   Access to standard Tk dialog boxes.
+
+:mod:`tkSimpleDialog`
+   Basic dialogs and convenience functions.
+
+:mod:`Tkdnd`
+   Drag-and-drop support for :mod:`Tkinter`. This is experimental and should become
+   deprecated when it is replaced  with the Tk DND.
+
+:mod:`turtle`
+   Turtle graphics in a Tk window.
+
+
+Tkinter Life Preserver
+----------------------
+
+.. sectionauthor:: Matt Conway
+
+
+This section is not designed to be an exhaustive tutorial on either Tk or
+Tkinter.  Rather, it is intended as a stop gap, providing some introductory
+orientation on the system.
+
+.. % Converted to LaTeX by Mike Clarkson.
+
+Credits:
+
+* Tkinter was written by Steen Lumholt and Guido van Rossum.
+
+* Tk was written by John Ousterhout while at Berkeley.
+
+* This Life Preserver was written by Matt Conway at the University of Virginia.
+
+* The html rendering, and some liberal editing, was produced from a FrameMaker
+  version by Ken Manheimer.
+
+* Fredrik Lundh elaborated and revised the class interface descriptions, to get
+  them current with Tk 4.2.
+
+* Mike Clarkson converted the documentation to LaTeX, and compiled the  User
+  Interface chapter of the reference manual.
+
+
+How To Use This Section
+^^^^^^^^^^^^^^^^^^^^^^^
+
+This section is designed in two parts: the first half (roughly) covers
+background material, while the second half can be taken to the keyboard as a
+handy reference.
+
+When trying to answer questions of the form "how do I do blah", it is often best
+to find out how to do"blah" in straight Tk, and then convert this back into the
+corresponding :mod:`Tkinter` call. Python programmers can often guess at the
+correct Python command by looking at the Tk documentation. This means that in
+order to use Tkinter, you will have to know a little bit about Tk. This document
+can't fulfill that role, so the best we can do is point you to the best
+documentation that exists. Here are some hints:
+
+* The authors strongly suggest getting a copy of the Tk man pages. Specifically,
+  the man pages in the ``mann`` directory are most useful. The ``man3`` man pages
+  describe the C interface to the Tk library and thus are not especially helpful
+  for script writers.
+
+* Addison-Wesley publishes a book called Tcl and the Tk Toolkit by John
+  Ousterhout (ISBN 0-201-63337-X) which is a good introduction to Tcl and Tk for
+  the novice.  The book is not exhaustive, and for many details it defers to the
+  man pages.
+
+* :file:`Tkinter.py` is a last resort for most, but can be a good place to go
+  when nothing else makes sense.
+
+
+.. seealso::
+
+   `ActiveState Tcl Home Page <http://tcl.activestate.com/>`_
+      The Tk/Tcl development is largely taking place at ActiveState.
+
+   `Tcl and the Tk Toolkit <http://www.amazon.com/exec/obidos/ASIN/020163337X>`_
+      The book by John Ousterhout, the inventor of Tcl .
+
+   `Practical Programming in Tcl and Tk <http://www.amazon.com/exec/obidos/ASIN/0130220280>`_
+      Brent Welch's encyclopedic book.
+
+
+A Simple Hello World Program
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. % HelloWorld.html
+.. % begin{latexonly}
+.. % \begin{figure}[hbtp]
+.. % \centerline{\epsfig{file=HelloWorld.gif,width=.9\textwidth}}
+.. % \vspace{.5cm}
+.. % \caption{HelloWorld gadget image}
+.. % \end{figure}
+.. % See also the hello-world \ulink{notes}{classes/HelloWorld-notes.html} and
+.. % \ulink{summary}{classes/HelloWorld-summary.html}.
+.. % end{latexonly}
+
+::
+
+   from Tkinter import *
+
+   class Application(Frame):
+       def say_hi(self):
+           print "hi there, everyone!"
+
+       def createWidgets(self):
+           self.QUIT = Button(self)
+           self.QUIT["text"] = "QUIT"
+           self.QUIT["fg"]   = "red"
+           self.QUIT["command"] =  self.quit
+
+           self.QUIT.pack({"side": "left"})
+
+           self.hi_there = Button(self)
+           self.hi_there["text"] = "Hello",
+           self.hi_there["command"] = self.say_hi
+
+           self.hi_there.pack({"side": "left"})
+
+       def __init__(self, master=None):
+           Frame.__init__(self, master)
+           self.pack()
+           self.createWidgets()
+
+   root = Tk()
+   app = Application(master=root)
+   app.mainloop()
+   root.destroy()
+
+
+A (Very) Quick Look at Tcl/Tk
+-----------------------------
+
+The class hierarchy looks complicated, but in actual practice, application
+programmers almost always refer to the classes at the very bottom of the
+hierarchy.
+
+.. % BriefTclTk.html
+
+Notes:
+
+* These classes are provided for the purposes of organizing certain functions
+  under one namespace. They aren't meant to be instantiated independently.
+
+* The :class:`Tk` class is meant to be instantiated only once in an application.
+  Application programmers need not instantiate one explicitly, the system creates
+  one whenever any of the other classes are instantiated.
+
+* The :class:`Widget` class is not meant to be instantiated, it is meant only
+  for subclassing to make "real" widgets (in C++, this is called an 'abstract
+  class').
+
+To make use of this reference material, there will be times when you will need
+to know how to read short passages of Tk and how to identify the various parts
+of a Tk command.   (See section :ref:`tkinter-basic-mapping` for the
+:mod:`Tkinter` equivalents of what's below.)
+
+Tk scripts are Tcl programs.  Like all Tcl programs, Tk scripts are just lists
+of tokens separated by spaces.  A Tk widget is just its *class*, the *options*
+that help configure it, and the *actions* that make it do useful things.
+
+To make a widget in Tk, the command is always of the form::
+
+   classCommand newPathname options
+
+*classCommand*
+   denotes which kind of widget to make (a button, a label, a menu...)
+
+*newPathname*
+   is the new name for this widget.  All names in Tk must be unique.  To help
+   enforce this, widgets in Tk are named with *pathnames*, just like files in a
+   file system.  The top level widget, the *root*, is called ``.`` (period) and
+   children are delimited by more periods.  For example,
+   ``.myApp.controlPanel.okButton`` might be the name of a widget.
+
+*options*
+   configure the widget's appearance and in some cases, its behavior.  The options
+   come in the form of a list of flags and values. Flags are preceded by a '-',
+   like Unix shell command flags, and values are put in quotes if they are more
+   than one word.
+
+For example::
+
+   button   .fred   -fg red -text "hi there"
+      ^       ^     \_____________________/
+      |       |                |
+    class    new            options
+   command  widget  (-opt val -opt val ...)
+
+Once created, the pathname to the widget becomes a new command.  This new
+*widget command* is the programmer's handle for getting the new widget to
+perform some *action*.  In C, you'd express this as someAction(fred,
+someOptions), in C++, you would express this as fred.someAction(someOptions),
+and in Tk, you say::
+
+   .fred someAction someOptions 
+
+Note that the object name, ``.fred``, starts with a dot.
+
+As you'd expect, the legal values for *someAction* will depend on the widget's
+class: ``.fred disable`` works if fred is a button (fred gets greyed out), but
+does not work if fred is a label (disabling of labels is not supported in Tk).
+
+The legal values of *someOptions* is action dependent.  Some actions, like
+``disable``, require no arguments, others, like a text-entry box's ``delete``
+command, would need arguments to specify what range of text to delete.
+
+
+.. _tkinter-basic-mapping:
+
+Mapping Basic Tk into Tkinter
+-----------------------------
+
+Class commands in Tk correspond to class constructors in Tkinter. ::
+
+   button .fred                =====>  fred = Button()
+
+The master of an object is implicit in the new name given to it at creation
+time.  In Tkinter, masters are specified explicitly. ::
+
+   button .panel.fred          =====>  fred = Button(panel)
+
+The configuration options in Tk are given in lists of hyphened tags followed by
+values.  In Tkinter, options are specified as keyword-arguments in the instance
+constructor, and keyword-args for configure calls or as instance indices, in
+dictionary style, for established instances.  See section
+:ref:`tkinter-setting-options` on setting options. ::
+
+   button .fred -fg red        =====>  fred = Button(panel, fg = "red")
+   .fred configure -fg red     =====>  fred["fg"] = red
+                               OR ==>  fred.config(fg = "red")
+
+In Tk, to perform an action on a widget, use the widget name as a command, and
+follow it with an action name, possibly with arguments (options).  In Tkinter,
+you call methods on the class instance to invoke actions on the widget.  The
+actions (methods) that a given widget can perform are listed in the Tkinter.py
+module. ::
+
+   .fred invoke                =====>  fred.invoke()
+
+To give a widget to the packer (geometry manager), you call pack with optional
+arguments.  In Tkinter, the Pack class holds all this functionality, and the
+various forms of the pack command are implemented as methods.  All widgets in
+:mod:`Tkinter` are subclassed from the Packer, and so inherit all the packing
+methods. See the :mod:`Tix` module documentation for additional information on
+the Form geometry manager. ::
+
+   pack .fred -side left       =====>  fred.pack(side = "left")
+
+
+How Tk and Tkinter are Related
+------------------------------
+
+.. % Relationship.html
+
+.. note::
+
+   This was derived from a graphical image; the image will be used more directly in
+   a subsequent version of this document.
+
+From the top down:
+
+Your App Here (Python)
+   A Python application makes a :mod:`Tkinter` call.
+
+Tkinter (Python Module)
+   This call (say, for example, creating a button widget), is implemented in the
+   *Tkinter* module, which is written in Python.  This Python function will parse
+   the commands and the arguments and convert them into a form that makes them look
+   as if they had come from a Tk script instead of a Python script.
+
+tkinter (C)
+   These commands and their arguments will be passed to a C function in the
+   *tkinter* - note the lowercase - extension module.
+
+Tk Widgets (C and Tcl)
+   This C function is able to make calls into other C modules, including the C
+   functions that make up the Tk library.  Tk is implemented in C and some Tcl.
+   The Tcl part of the Tk widgets is used to bind certain default behaviors to
+   widgets, and is executed once at the point where the Python :mod:`Tkinter`
+   module is imported. (The user never sees this stage).
+
+Tk (C)
+   The Tk part of the Tk Widgets implement the final mapping to ...
+
+Xlib (C)
+   the Xlib library to draw graphics on the screen.
+
+
+Handy Reference
+---------------
+
+
+.. _tkinter-setting-options:
+
+Setting Options
+^^^^^^^^^^^^^^^
+
+Options control things like the color and border width of a widget. Options can
+be set in three ways:
+
+At object creation time, using keyword arguments
+   ::
+
+      fred = Button(self, fg = "red", bg = "blue")
+
+After object creation, treating the option name like a dictionary index
+   ::
+
+      fred["fg"] = "red"
+      fred["bg"] = "blue"
+
+Use the config() method to update multiple attrs subsequent to object creation
+   ::
+
+      fred.config(fg = "red", bg = "blue")
+
+For a complete explanation of a given option and its behavior, see the Tk man
+pages for the widget in question.
+
+Note that the man pages list "STANDARD OPTIONS" and "WIDGET SPECIFIC OPTIONS"
+for each widget.  The former is a list of options that are common to many
+widgets, the latter are the options that are idiosyncratic to that particular
+widget.  The Standard Options are documented on the :manpage:`options(3)` man
+page.
+
+No distinction between standard and widget-specific options is made in this
+document.  Some options don't apply to some kinds of widgets. Whether a given
+widget responds to a particular option depends on the class of the widget;
+buttons have a ``command`` option, labels do not.
+
+The options supported by a given widget are listed in that widget's man page, or
+can be queried at runtime by calling the :meth:`config` method without
+arguments, or by calling the :meth:`keys` method on that widget.  The return
+value of these calls is a dictionary whose key is the name of the option as a
+string (for example, ``'relief'``) and whose values are 5-tuples.
+
+Some options, like ``bg`` are synonyms for common options with long names
+(``bg`` is shorthand for "background"). Passing the ``config()`` method the name
+of a shorthand option will return a 2-tuple, not 5-tuple. The 2-tuple passed
+back will contain the name of the synonym and the "real" option (such as
+``('bg', 'background')``).
+
++-------+---------------------------------+--------------+
+| Index | Meaning                         | Example      |
++=======+=================================+==============+
+| 0     | option name                     | ``'relief'`` |
++-------+---------------------------------+--------------+
+| 1     | option name for database lookup | ``'relief'`` |
++-------+---------------------------------+--------------+
+| 2     | option class for database       | ``'Relief'`` |
+|       | lookup                          |              |
++-------+---------------------------------+--------------+
+| 3     | default value                   | ``'raised'`` |
++-------+---------------------------------+--------------+
+| 4     | current value                   | ``'groove'`` |
++-------+---------------------------------+--------------+
+
+Example::
+
+   >>> print fred.config()
+   {'relief' : ('relief', 'relief', 'Relief', 'raised', 'groove')}
+
+Of course, the dictionary printed will include all the options available and
+their values.  This is meant only as an example.
+
+
+The Packer
+^^^^^^^^^^
+
+.. index:: single: packing (widgets)
+
+.. % Packer.html
+
+The packer is one of Tk's geometry-management mechanisms.    Geometry managers
+are used to specify the relative positioning of the positioning of widgets
+within their container - their mutual *master*.  In contrast to the more
+cumbersome *placer* (which is used less commonly, and we do not cover here), the
+packer takes qualitative relationship specification - *above*, *to the left of*,
+*filling*, etc - and works everything out to determine the exact placement
+coordinates for you.
+
+.. % See also \citetitle[classes/ClassPacker.html]{the Packer class interface}.
+
+The size of any *master* widget is determined by the size of the "slave widgets"
+inside.  The packer is used to control where slave widgets appear inside the
+master into which they are packed.  You can pack widgets into frames, and frames
+into other frames, in order to achieve the kind of layout you desire.
+Additionally, the arrangement is dynamically adjusted to accommodate incremental
+changes to the configuration, once it is packed.
+
+Note that widgets do not appear until they have had their geometry specified
+with a geometry manager.  It's a common early mistake to leave out the geometry
+specification, and then be surprised when the widget is created but nothing
+appears.  A widget will appear only after it has had, for example, the packer's
+:meth:`pack` method applied to it.
+
+The pack() method can be called with keyword-option/value pairs that control
+where the widget is to appear within its container, and how it is to behave when
+the main application window is resized.  Here are some examples::
+
+   fred.pack()                     # defaults to side = "top"
+   fred.pack(side = "left")
+   fred.pack(expand = 1)
+
+
+Packer Options
+^^^^^^^^^^^^^^
+
+For more extensive information on the packer and the options that it can take,
+see the man pages and page 183 of John Ousterhout's book.
+
+anchor 
+   Anchor type.  Denotes where the packer is to place each slave in its parcel.
+
+expand
+   Boolean, ``0`` or ``1``.
+
+fill
+   Legal values: ``'x'``, ``'y'``, ``'both'``, ``'none'``.
+
+ipadx and ipady
+   A distance - designating internal padding on each side of the slave widget.
+
+padx and pady
+   A distance - designating external padding on each side of the slave widget.
+
+side
+   Legal values are: ``'left'``, ``'right'``, ``'top'``, ``'bottom'``.
+
+
+Coupling Widget Variables
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The current-value setting of some widgets (like text entry widgets) can be
+connected directly to application variables by using special options.  These
+options are ``variable``, ``textvariable``, ``onvalue``, ``offvalue``, and
+``value``.  This connection works both ways: if the variable changes for any
+reason, the widget it's connected to will be updated to reflect the new value.
+
+.. % VarCouplings.html
+
+Unfortunately, in the current implementation of :mod:`Tkinter` it is not
+possible to hand over an arbitrary Python variable to a widget through a
+``variable`` or ``textvariable`` option.  The only kinds of variables for which
+this works are variables that are subclassed from a class called Variable,
+defined in the :mod:`Tkinter` module.
+
+There are many useful subclasses of Variable already defined:
+:class:`StringVar`, :class:`IntVar`, :class:`DoubleVar`, and
+:class:`BooleanVar`.  To read the current value of such a variable, call the
+:meth:`get` method on it, and to change its value you call the :meth:`set`
+method.  If you follow this protocol, the widget will always track the value of
+the variable, with no further intervention on your part.
+
+For example::
+
+   class App(Frame):
+       def __init__(self, master=None):
+           Frame.__init__(self, master)
+           self.pack()
+
+           self.entrythingy = Entry()
+           self.entrythingy.pack()
+
+           # here is the application variable
+           self.contents = StringVar()
+           # set it to some value
+           self.contents.set("this is a variable")
+           # tell the entry widget to watch this variable
+           self.entrythingy["textvariable"] = self.contents
+
+           # and here we get a callback when the user hits return.
+           # we will have the program print out the value of the
+           # application variable when the user hits return
+           self.entrythingy.bind('<Key-Return>',
+                                 self.print_contents)
+
+       def print_contents(self, event):
+           print "hi. contents of entry is now ---->", \
+                 self.contents.get()
+
+
+The Window Manager
+^^^^^^^^^^^^^^^^^^
+
+.. index:: single: window manager (widgets)
+
+.. % WindowMgr.html
+
+In Tk, there is a utility command, ``wm``, for interacting with the window
+manager.  Options to the ``wm`` command allow you to control things like titles,
+placement, icon bitmaps, and the like.  In :mod:`Tkinter`, these commands have
+been implemented as methods on the :class:`Wm` class.  Toplevel widgets are
+subclassed from the :class:`Wm` class, and so can call the :class:`Wm` methods
+directly.
+
+To get at the toplevel window that contains a given widget, you can often just
+refer to the widget's master.  Of course if the widget has been packed inside of
+a frame, the master won't represent a toplevel window.  To get at the toplevel
+window that contains an arbitrary widget, you can call the :meth:`_root` method.
+This method begins with an underscore to denote the fact that this function is
+part of the implementation, and not an interface to Tk functionality.
+
+.. % See also \citetitle[classes/ClassWm.html]{the Wm class interface}.
+
+Here are some examples of typical usage::
+
+   from Tkinter import *
+   class App(Frame):
+       def __init__(self, master=None):
+           Frame.__init__(self, master)
+           self.pack()
+
+
+   # create the application
+   myapp = App()
+
+   #
+   # here are method calls to the window manager class
+   #
+   myapp.master.title("My Do-Nothing Application")
+   myapp.master.maxsize(1000, 400)
+
+   # start the program
+   myapp.mainloop()
+
+
+Tk Option Data Types
+^^^^^^^^^^^^^^^^^^^^
+
+.. index:: single: Tk Option Data Types
+
+.. % OptionTypes.html
+
+anchor
+   Legal values are points of the compass: ``"n"``, ``"ne"``, ``"e"``, ``"se"``,
+   ``"s"``, ``"sw"``, ``"w"``, ``"nw"``, and also ``"center"``.
+
+bitmap
+   There are eight built-in, named bitmaps: ``'error'``, ``'gray25'``,
+   ``'gray50'``, ``'hourglass'``, ``'info'``, ``'questhead'``, ``'question'``,
+   ``'warning'``.  To specify an X bitmap filename, give the full path to the file,
+   preceded with an ``@``, as in ``"@/usr/contrib/bitmap/gumby.bit"``.
+
+boolean
+   You can pass integers 0 or 1 or the strings ``"yes"`` or ``"no"`` .
+
+callback
+   This is any Python function that takes no arguments.  For example::
+
+      def print_it():
+              print "hi there"
+      fred["command"] = print_it
+
+color
+   Colors can be given as the names of X colors in the rgb.txt file, or as strings
+   representing RGB values in 4 bit: ``"#RGB"``, 8 bit: ``"#RRGGBB"``, 12 bit"
+   ``"#RRRGGGBBB"``, or 16 bit ``"#RRRRGGGGBBBB"`` ranges, where R,G,B here
+   represent any legal hex digit.  See page 160 of Ousterhout's book for details.
+
+cursor
+   The standard X cursor names from :file:`cursorfont.h` can be used, without the
+   ``XC_`` prefix.  For example to get a hand cursor (:const:`XC_hand2`), use the
+   string ``"hand2"``.  You can also specify a bitmap and mask file of your own.
+   See page 179 of Ousterhout's book.
+
+distance
+   Screen distances can be specified in either pixels or absolute distances.
+   Pixels are given as numbers and absolute distances as strings, with the trailing
+   character denoting units: ``c`` for centimetres, ``i`` for inches, ``m`` for
+   millimetres, ``p`` for printer's points.  For example, 3.5 inches is expressed
+   as ``"3.5i"``.
+
+font
+   Tk uses a list font name format, such as ``{courier 10 bold}``. Font sizes with
+   positive numbers are measured in points; sizes with negative numbers are
+   measured in pixels.
+
+geometry
+   This is a string of the form ``widthxheight``, where width and height are
+   measured in pixels for most widgets (in characters for widgets displaying text).
+   For example: ``fred["geometry"] = "200x100"``.
+
+justify
+   Legal values are the strings: ``"left"``, ``"center"``, ``"right"``, and
+   ``"fill"``.
+
+region
+   This is a string with four space-delimited elements, each of which is a legal
+   distance (see above).  For example: ``"2 3 4 5"`` and ``"3i 2i 4.5i 2i"`` and
+   ``"3c 2c 4c 10.43c"``  are all legal regions.
+
+relief
+   Determines what the border style of a widget will be.  Legal values are:
+   ``"raised"``, ``"sunken"``, ``"flat"``, ``"groove"``, and ``"ridge"``.
+
+scrollcommand
+   This is almost always the :meth:`set` method of some scrollbar widget, but can
+   be any widget method that takes a single argument.   Refer to the file
+   :file:`Demo/tkinter/matt/canvas-with-scrollbars.py` in the Python source
+   distribution for an example.
+
+wrap:
+   Must be one of: ``"none"``, ``"char"``, or ``"word"``.
+
+
+Bindings and Events
+^^^^^^^^^^^^^^^^^^^
+
+.. index::
+   single: bind (widgets)
+   single: events (widgets)
+
+.. % Bindings.html
+
+The bind method from the widget command allows you to watch for certain events
+and to have a callback function trigger when that event type occurs.  The form
+of the bind method is::
+
+   def bind(self, sequence, func, add=''):
+
+where:
+
+sequence
+   is a string that denotes the target kind of event.  (See the bind man page and
+   page 201 of John Ousterhout's book for details).
+
+func
+   is a Python function, taking one argument, to be invoked when the event occurs.
+   An Event instance will be passed as the argument. (Functions deployed this way
+   are commonly known as *callbacks*.)
+
+add
+   is optional, either ``''`` or ``'+'``.  Passing an empty string denotes that
+   this binding is to replace any other bindings that this event is associated
+   with.  Passing a ``'+'`` means that this function is to be added to the list
+   of functions bound to this event type.
+
+For example::
+
+   def turnRed(self, event):
+       event.widget["activeforeground"] = "red"
+
+   self.button.bind("<Enter>", self.turnRed)
+
+Notice how the widget field of the event is being accessed in the
+:meth:`turnRed` callback.  This field contains the widget that caught the X
+event.  The following table lists the other event fields you can access, and how
+they are denoted in Tk, which can be useful when referring to the Tk man pages.
+::
+
+   Tk      Tkinter Event Field             Tk      Tkinter Event Field 
+   --      -------------------             --      -------------------
+   %f      focus                           %A      char
+   %h      height                          %E      send_event
+   %k      keycode                         %K      keysym
+   %s      state                           %N      keysym_num
+   %t      time                            %T      type
+   %w      width                           %W      widget
+   %x      x                               %X      x_root
+   %y      y                               %Y      y_root
+
+
+The index Parameter
+^^^^^^^^^^^^^^^^^^^
+
+A number of widgets require"index" parameters to be passed.  These are used to
+point at a specific place in a Text widget, or to particular characters in an
+Entry widget, or to particular menu items in a Menu widget.
+
+.. % Index.html
+
+Entry widget indexes (index, view index, etc.)
+   Entry widgets have options that refer to character positions in the text being
+   displayed.  You can use these :mod:`Tkinter` functions to access these special
+   points in text widgets:
+
+   AtEnd()
+      refers to the last position in the text
+
+   AtInsert()
+      refers to the point where the text cursor is
+
+   AtSelFirst()
+      indicates the beginning point of the selected text
+
+   AtSelLast()
+      denotes the last point of the selected text and finally
+
+   At(x[, y])
+      refers to the character at pixel location *x*, *y* (with *y* not used in the
+      case of a text entry widget, which contains a single line of text).
+
+Text widget indexes
+   The index notation for Text widgets is very rich and is best described in the Tk
+   man pages.
+
+Menu indexes (menu.invoke(), menu.entryconfig(), etc.)
+   Some options and methods for menus manipulate specific menu entries. Anytime a
+   menu index is needed for an option or a parameter, you may pass in:
+
+   * an integer which refers to the numeric position of the entry in the widget,
+     counted from the top, starting with 0;
+
+   * the string ``'active'``, which refers to the menu position that is currently
+     under the cursor;
+
+   * the string ``"last"`` which refers to the last menu item;
+
+   * An integer preceded by ``@``, as in ``@6``, where the integer is interpreted
+     as a y pixel coordinate in the menu's coordinate system;
+
+   * the string ``"none"``, which indicates no menu entry at all, most often used
+     with menu.activate() to deactivate all entries, and finally,
+
+   * a text string that is pattern matched against the label of the menu entry, as
+     scanned from the top of the menu to the bottom.  Note that this index type is
+     considered after all the others, which means that matches for menu items
+     labelled ``last``, ``active``, or ``none`` may be interpreted as the above
+     literals, instead.
+
+
+Images
+^^^^^^
+
+Bitmap/Pixelmap images can be created through the subclasses of
+:class:`Tkinter.Image`:
+
+* :class:`BitmapImage` can be used for X11 bitmap data.
+
+* :class:`PhotoImage` can be used for GIF and PPM/PGM color bitmaps.
+
+Either type of image is created through either the ``file`` or the ``data``
+option (other options are available as well).
+
+The image object can then be used wherever an ``image`` option is supported by
+some widget (e.g. labels, buttons, menus). In these cases, Tk will not keep a
+reference to the image. When the last Python reference to the image object is
+deleted, the image data is deleted as well, and Tk will display an empty box
+wherever the image was used.
+
diff --git a/Doc/library/token.rst b/Doc/library/token.rst
new file mode 100644
index 0000000..5bf0ea8
--- /dev/null
+++ b/Doc/library/token.rst
@@ -0,0 +1,47 @@
+
+:mod:`token` --- Constants used with Python parse trees
+=======================================================
+
+.. module:: token
+   :synopsis: Constants representing terminal nodes of the parse tree.
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+This module provides constants which represent the numeric values of leaf nodes
+of the parse tree (terminal tokens).  Refer to the file :file:`Grammar/Grammar`
+in the Python distribution for the definitions of the names in the context of
+the language grammar.  The specific numeric values which the names map to may
+change between Python versions.
+
+This module also provides one data object and some functions.  The functions
+mirror definitions in the Python C header files.
+
+
+.. data:: tok_name
+
+   Dictionary mapping the numeric values of the constants defined in this module
+   back to name strings, allowing more human-readable representation of parse trees
+   to be generated.
+
+
+.. function:: ISTERMINAL(x)
+
+   Return true for terminal token values.
+
+
+.. function:: ISNONTERMINAL(x)
+
+   Return true for non-terminal token values.
+
+
+.. function:: ISEOF(x)
+
+   Return true if *x* is the marker indicating the end of input.
+
+
+.. seealso::
+
+   Module :mod:`parser`
+      The second example for the :mod:`parser` module shows how to use the
+      :mod:`symbol` module.
+
diff --git a/Doc/library/tokenize.rst b/Doc/library/tokenize.rst
new file mode 100644
index 0000000..61f2c4d
--- /dev/null
+++ b/Doc/library/tokenize.rst
@@ -0,0 +1,122 @@
+
+:mod:`tokenize` --- Tokenizer for Python source
+===============================================
+
+.. module:: tokenize
+   :synopsis: Lexical scanner for Python source code.
+.. moduleauthor:: Ka Ping Yee
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+The :mod:`tokenize` module provides a lexical scanner for Python source code,
+implemented in Python.  The scanner in this module returns comments as tokens as
+well, making it useful for implementing "pretty-printers," including colorizers
+for on-screen displays.
+
+The primary entry point is a generator:
+
+
+.. function:: generate_tokens(readline)
+
+   The :func:`generate_tokens` generator requires one argment, *readline*, which
+   must be a callable object which provides the same interface as the
+   :meth:`readline` method of built-in file objects (see section
+   :ref:`bltin-file-objects`).  Each call to the function should return one line of
+   input as a string.
+
+   The generator produces 5-tuples with these members: the token type; the token
+   string; a 2-tuple ``(srow, scol)`` of ints specifying the row and column where
+   the token begins in the source; a 2-tuple ``(erow, ecol)`` of ints specifying
+   the row and column where the token ends in the source; and the line on which the
+   token was found. The line passed is the *logical* line; continuation lines are
+   included.
+
+   .. versionadded:: 2.2
+
+An older entry point is retained for backward compatibility:
+
+
+.. function:: tokenize(readline[, tokeneater])
+
+   The :func:`tokenize` function accepts two parameters: one representing the input
+   stream, and one providing an output mechanism for :func:`tokenize`.
+
+   The first parameter, *readline*, must be a callable object which provides the
+   same interface as the :meth:`readline` method of built-in file objects (see
+   section :ref:`bltin-file-objects`).  Each call to the function should return one
+   line of input as a string. Alternately, *readline* may be a callable object that
+   signals completion by raising :exc:`StopIteration`.
+
+   .. versionchanged:: 2.5
+      Added :exc:`StopIteration` support.
+
+   The second parameter, *tokeneater*, must also be a callable object.  It is
+   called once for each token, with five arguments, corresponding to the tuples
+   generated by :func:`generate_tokens`.
+
+All constants from the :mod:`token` module are also exported from
+:mod:`tokenize`, as are two additional token type values that might be passed to
+the *tokeneater* function by :func:`tokenize`:
+
+
+.. data:: COMMENT
+
+   Token value used to indicate a comment.
+
+
+.. data:: NL
+
+   Token value used to indicate a non-terminating newline.  The NEWLINE token
+   indicates the end of a logical line of Python code; NL tokens are generated when
+   a logical line of code is continued over multiple physical lines.
+
+Another function is provided to reverse the tokenization process. This is useful
+for creating tools that tokenize a script, modify the token stream, and write
+back the modified script.
+
+
+.. function:: untokenize(iterable)
+
+   Converts tokens back into Python source code.  The *iterable* must return
+   sequences with at least two elements, the token type and the token string.  Any
+   additional sequence elements are ignored.
+
+   The reconstructed script is returned as a single string.  The result is
+   guaranteed to tokenize back to match the input so that the conversion is
+   lossless and round-trips are assured.  The guarantee applies only to the token
+   type and token string as the spacing between tokens (column positions) may
+   change.
+
+   .. versionadded:: 2.5
+
+Example of a script re-writer that transforms float literals into Decimal
+objects::
+
+   def decistmt(s):
+       """Substitute Decimals for floats in a string of statements.
+
+       >>> from decimal import Decimal
+       >>> s = 'print +21.3e-5*-.1234/81.7'
+       >>> decistmt(s)
+       "print +Decimal ('21.3e-5')*-Decimal ('.1234')/Decimal ('81.7')"
+
+       >>> exec(s)
+       -3.21716034272e-007
+       >>> exec(decistmt(s))
+       -3.217160342717258261933904529E-7
+
+       """
+       result = []
+       g = generate_tokens(StringIO(s).readline)   # tokenize the string
+       for toknum, tokval, _, _, _  in g:
+           if toknum == NUMBER and '.' in tokval:  # replace NUMBER tokens
+               result.extend([
+                   (NAME, 'Decimal'),
+                   (OP, '('),
+                   (STRING, repr(tokval)),
+                   (OP, ')')
+               ])
+           else:
+               result.append((toknum, tokval))
+       return untokenize(result)
+
diff --git a/Doc/library/trace.rst b/Doc/library/trace.rst
new file mode 100644
index 0000000..91cf1a4
--- /dev/null
+++ b/Doc/library/trace.rst
@@ -0,0 +1,128 @@
+
+:mod:`trace` --- Trace or track Python statement execution
+==========================================================
+
+.. module:: trace
+   :synopsis: Trace or track Python statement execution.
+
+
+The :mod:`trace` module allows you to trace program execution, generate
+annotated statement coverage listings, print caller/callee relationships and
+list functions executed during a program run.  It can be used in another program
+or from the command line.
+
+
+.. _trace-cli:
+
+Command Line Usage
+------------------
+
+The :mod:`trace` module can be invoked from the command line.  It can be as
+simple as ::
+
+   python -m trace --count somefile.py ...
+
+The above will generate annotated listings of all Python modules imported during
+the execution of :file:`somefile.py`.
+
+The following command-line arguments are supported:
+
+:option:`--trace`, :option:`-t`
+   Display lines as they are executed.
+
+:option:`--count`, :option:`-c`
+   Produce a set of  annotated listing files upon program completion that shows how
+   many times each statement was executed.
+
+:option:`--report`, :option:`-r`
+   Produce an annotated list from an earlier program run that used the
+   :option:`--count` and :option:`--file` arguments.
+
+:option:`--no-report`, :option:`-R`
+   Do not generate annotated listings.  This is useful if you intend to make
+   several runs with :option:`--count` then produce a single set of annotated
+   listings at the end.
+
+:option:`--listfuncs`, :option:`-l`
+   List the functions executed by running the program.
+
+:option:`--trackcalls`, :option:`-T`
+   Generate calling relationships exposed by running the program.
+
+:option:`--file`, :option:`-f`
+   Name a file containing (or to contain) counts.
+
+:option:`--coverdir`, :option:`-C`
+   Name a directory in which to save annotated listing files.
+
+:option:`--missing`, :option:`-m`
+   When generating annotated listings, mark lines which were not executed with
+   '``>>>>>>``'.
+
+:option:`--summary`, :option:`-s`
+   When using :option:`--count` or :option:`--report`, write a brief summary to
+   stdout for each file processed.
+
+:option:`--ignore-module`
+   Ignore the named module and its submodules (if it is a package).  May be given
+   multiple times.
+
+:option:`--ignore-dir`
+   Ignore all modules and packages in the named directory and subdirectories.  May
+   be given multiple times.
+
+
+.. _trace-api:
+
+Programming Interface
+---------------------
+
+
+.. class:: Trace([count=1[, trace=1[, countfuncs=0[, countcallers=0[, ignoremods=()[, ignoredirs=()[, infile=None[, outfile=None]]]]]]]])
+
+   Create an object to trace execution of a single statement or expression. All
+   parameters are optional.  *count* enables counting of line numbers. *trace*
+   enables line execution tracing.  *countfuncs* enables listing of the functions
+   called during the run.  *countcallers* enables call relationship tracking.
+   *ignoremods* is a list of modules or packages to ignore.  *ignoredirs* is a list
+   of directories whose modules or packages should be ignored.  *infile* is the
+   file from which to read stored count information.  *outfile* is a file in which
+   to write updated count information.
+
+
+.. method:: Trace.run(cmd)
+
+   Run *cmd* under control of the Trace object with the current tracing parameters.
+
+
+.. method:: Trace.runctx(cmd[, globals=None[, locals=None]])
+
+   Run *cmd* under control of the Trace object with the current tracing parameters
+   in the defined global and local environments.  If not defined, *globals* and
+   *locals* default to empty dictionaries.
+
+
+.. method:: Trace.runfunc(func, *args, **kwds)
+
+   Call *func* with the given arguments under control of the :class:`Trace` object
+   with the current tracing parameters.
+
+This is a simple example showing the use of this module::
+
+   import sys
+   import trace
+
+   # create a Trace object, telling it what to ignore, and whether to
+   # do tracing or line-counting or both.
+   tracer = trace.Trace(
+       ignoredirs=[sys.prefix, sys.exec_prefix],
+       trace=0,
+       count=1)
+
+   # run the new command using the given tracer
+   tracer.run('main()')
+
+   # make a report, placing output in /tmp
+   r = tracer.results()
+   r.write_results(show_missing=True, coverdir="/tmp")
+
diff --git a/Doc/library/traceback.rst b/Doc/library/traceback.rst
new file mode 100644
index 0000000..ec8687f
--- /dev/null
+++ b/Doc/library/traceback.rst
@@ -0,0 +1,160 @@
+
+:mod:`traceback` --- Print or retrieve a stack traceback
+========================================================
+
+.. module:: traceback
+   :synopsis: Print or retrieve a stack traceback.
+
+
+This module provides a standard interface to extract, format and print stack
+traces of Python programs.  It exactly mimics the behavior of the Python
+interpreter when it prints a stack trace.  This is useful when you want to print
+stack traces under program control, such as in a "wrapper" around the
+interpreter.
+
+.. index:: object: traceback
+
+The module uses traceback objects --- this is the object type that is stored in
+the ``sys.last_traceback`` variable and returned as the third item from
+:func:`sys.exc_info`.
+
+The module defines the following functions:
+
+
+.. function:: print_tb(traceback[, limit[, file]])
+
+   Print up to *limit* stack trace entries from *traceback*.  If *limit* is omitted
+   or ``None``, all entries are printed. If *file* is omitted or ``None``, the
+   output goes to ``sys.stderr``; otherwise it should be an open file or file-like
+   object to receive the output.
+
+
+.. function:: print_exception(type, value, traceback[, limit[, file]])
+
+   Print exception information and up to *limit* stack trace entries from
+   *traceback* to *file*. This differs from :func:`print_tb` in the following ways:
+   (1) if *traceback* is not ``None``, it prints a header ``Traceback (most recent
+   call last):``; (2) it prints the exception *type* and *value* after the stack
+   trace; (3) if *type* is :exc:`SyntaxError` and *value* has the appropriate
+   format, it prints the line where the syntax error occurred with a caret
+   indicating the approximate position of the error.
+
+
+.. function:: print_exc([limit[, file]])
+
+   This is a shorthand for ``print_exception(*sys.exc_info()``.
+
+
+.. function:: format_exc([limit])
+
+   This is like ``print_exc(limit)`` but returns a string instead of printing to a
+   file.
+
+   .. versionadded:: 2.4
+
+
+.. function:: print_last([limit[, file]])
+
+   This is a shorthand for ``print_exception(sys.last_type, sys.last_value,
+   sys.last_traceback, limit, file)``.
+
+
+.. function:: print_stack([f[, limit[, file]]])
+
+   This function prints a stack trace from its invocation point.  The optional *f*
+   argument can be used to specify an alternate stack frame to start.  The optional
+   *limit* and *file* arguments have the same meaning as for
+   :func:`print_exception`.
+
+
+.. function:: extract_tb(traceback[, limit])
+
+   Return a list of up to *limit* "pre-processed" stack trace entries extracted
+   from the traceback object *traceback*.  It is useful for alternate formatting of
+   stack traces.  If *limit* is omitted or ``None``, all entries are extracted.  A
+   "pre-processed" stack trace entry is a quadruple (*filename*, *line number*,
+   *function name*, *text*) representing the information that is usually printed
+   for a stack trace.  The *text* is a string with leading and trailing whitespace
+   stripped; if the source is not available it is ``None``.
+
+
+.. function:: extract_stack([f[, limit]])
+
+   Extract the raw traceback from the current stack frame.  The return value has
+   the same format as for :func:`extract_tb`.  The optional *f* and *limit*
+   arguments have the same meaning as for :func:`print_stack`.
+
+
+.. function:: format_list(list)
+
+   Given a list of tuples as returned by :func:`extract_tb` or
+   :func:`extract_stack`, return a list of strings ready for printing.  Each string
+   in the resulting list corresponds to the item with the same index in the
+   argument list.  Each string ends in a newline; the strings may contain internal
+   newlines as well, for those items whose source text line is not ``None``.
+
+
+.. function:: format_exception_only(type, value)
+
+   Format the exception part of a traceback.  The arguments are the exception type
+   and value such as given by ``sys.last_type`` and ``sys.last_value``.  The return
+   value is a list of strings, each ending in a newline.  Normally, the list
+   contains a single string; however, for :exc:`SyntaxError` exceptions, it
+   contains several lines that (when printed) display detailed information about
+   where the syntax error occurred.  The message indicating which exception
+   occurred is the always last string in the list.
+
+
+.. function:: format_exception(type, value, tb[, limit])
+
+   Format a stack trace and the exception information.  The arguments  have the
+   same meaning as the corresponding arguments to :func:`print_exception`.  The
+   return value is a list of strings, each ending in a newline and some containing
+   internal newlines.  When these lines are concatenated and printed, exactly the
+   same text is printed as does :func:`print_exception`.
+
+
+.. function:: format_tb(tb[, limit])
+
+   A shorthand for ``format_list(extract_tb(tb, limit))``.
+
+
+.. function:: format_stack([f[, limit]])
+
+   A shorthand for ``format_list(extract_stack(f, limit))``.
+
+
+.. function:: tb_lineno(tb)
+
+   This function returns the current line number set in the traceback object.  This
+   function was necessary because in versions of Python prior to 2.3 when the
+   :option:`-O` flag was passed to Python the ``tb.tb_lineno`` was not updated
+   correctly.  This function has no use in versions past 2.3.
+
+
+.. _traceback-example:
+
+Traceback Example
+-----------------
+
+This simple example implements a basic read-eval-print loop, similar to (but
+less useful than) the standard Python interactive interpreter loop.  For a more
+complete implementation of the interpreter loop, refer to the :mod:`code`
+module. ::
+
+   import sys, traceback
+
+   def run_user_code(envdir):
+       source = raw_input(">>> ")
+       try:
+           exec(source, envdir)
+       except:
+           print "Exception in user code:"
+           print '-'*60
+           traceback.print_exc(file=sys.stdout)
+           print '-'*60
+
+   envdir = {}
+   while 1:
+       run_user_code(envdir)
+
diff --git a/Doc/library/tty.rst b/Doc/library/tty.rst
new file mode 100644
index 0000000..688faee
--- /dev/null
+++ b/Doc/library/tty.rst
@@ -0,0 +1,38 @@
+
+:mod:`tty` --- Terminal control functions
+=========================================
+
+.. module:: tty
+   :platform: Unix
+   :synopsis: Utility functions that perform common terminal control operations.
+.. moduleauthor:: Steen Lumholt
+.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
+
+
+The :mod:`tty` module defines functions for putting the tty into cbreak and raw
+modes.
+
+Because it requires the :mod:`termios` module, it will work only on Unix.
+
+The :mod:`tty` module defines the following functions:
+
+
+.. function:: setraw(fd[, when])
+
+   Change the mode of the file descriptor *fd* to raw. If *when* is omitted, it
+   defaults to :const:`termios.TCSAFLUSH`, and is passed to
+   :func:`termios.tcsetattr`.
+
+
+.. function:: setcbreak(fd[, when])
+
+   Change the mode of file descriptor *fd* to cbreak. If *when* is omitted, it
+   defaults to :const:`termios.TCSAFLUSH`, and is passed to
+   :func:`termios.tcsetattr`.
+
+
+.. seealso::
+
+   Module :mod:`termios`
+      Low-level terminal control interface.
+
diff --git a/Doc/library/turtle.rst b/Doc/library/turtle.rst
new file mode 100644
index 0000000..354bb11
--- /dev/null
+++ b/Doc/library/turtle.rst
@@ -0,0 +1,312 @@
+
+:mod:`turtle` --- Turtle graphics for Tk
+========================================
+
+.. module:: turtle
+   :platform: Tk
+   :synopsis: An environment for turtle graphics.
+.. moduleauthor:: Guido van Rossum <guido@python.org>
+
+
+.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
+
+
+The :mod:`turtle` module provides turtle graphics primitives, in both an
+object-oriented and procedure-oriented ways. Because it uses :mod:`Tkinter` for
+the underlying graphics, it needs a version of python installed with Tk support.
+
+The procedural interface uses a pen and a canvas which are automagically created
+when any of the functions are called.
+
+The :mod:`turtle` module defines the following functions:
+
+
+.. function:: degrees()
+
+   Set angle measurement units to degrees.
+
+
+.. function:: radians()
+
+   Set angle measurement units to radians.
+
+
+.. function:: setup(**kwargs)
+
+   Sets the size and position of the main window.  Keywords are:
+
+   * ``width``: either a size in pixels or a fraction of the screen. The default is
+     50% of the screen.
+
+   * ``height``: either a size in pixels or a fraction of the screen. The default
+     is 50% of the screen.
+
+   * ``startx``: starting position in pixels from the left edge of the screen.
+     ``None`` is the default value and  centers the window horizontally on screen.
+
+   * ``starty``: starting position in pixels from the top edge of the screen.
+     ``None`` is the default value and  centers the window vertically on screen.
+
+   Examples::
+
+      # Uses default geometry: 50% x 50% of screen, centered.
+      setup()  
+
+      # Sets window to 200x200 pixels, in upper left of screen
+      setup (width=200, height=200, startx=0, starty=0)
+
+      # Sets window to 75% of screen by 50% of screen, and centers it.
+      setup(width=.75, height=0.5, startx=None, starty=None)
+
+
+.. function:: title(title_str)
+
+   Set the window's title to *title*.
+
+
+.. function:: done()
+
+   Enters the Tk main loop.  The window will continue to  be displayed until the
+   user closes it or the process is killed.
+
+
+.. function:: reset()
+
+   Clear the screen, re-center the pen, and set variables to the default values.
+
+
+.. function:: clear()
+
+   Clear the screen.
+
+
+.. function:: tracer(flag)
+
+   Set tracing on/off (according to whether flag is true or not). Tracing means
+   line are drawn more slowly, with an animation of an arrow along the  line.
+
+
+.. function:: speed(speed)
+
+   Set the speed of the turtle. Valid values for the parameter *speed* are
+   ``'fastest'`` (no delay), ``'fast'``, (delay 5ms), ``'normal'`` (delay 10ms),
+   ``'slow'`` (delay 15ms), and ``'slowest'`` (delay 20ms).
+
+   .. versionadded:: 2.5
+
+
+.. function:: delay(delay)
+
+   Set the speed of the turtle to *delay*, which is given in ms.
+
+   .. versionadded:: 2.5
+
+
+.. function:: forward(distance)
+
+   Go forward *distance* steps.
+
+
+.. function:: backward(distance)
+
+   Go backward *distance* steps.
+
+
+.. function:: left(angle)
+
+   Turn left *angle* units. Units are by default degrees, but can be set via the
+   :func:`degrees` and :func:`radians` functions.
+
+
+.. function:: right(angle)
+
+   Turn right *angle* units. Units are by default degrees, but can be set via the
+   :func:`degrees` and :func:`radians` functions.
+
+
+.. function:: up()
+
+   Move the pen up --- stop drawing.
+
+
+.. function:: down()
+
+   Move the pen down --- draw when moving.
+
+
+.. function:: width(width)
+
+   Set the line width to *width*.
+
+
+.. function:: color(s)
+              color((r, g, b))
+              color(r, g, b)
+
+   Set the pen color.  In the first form, the color is specified as a Tk color
+   specification as a string.  The second form specifies the color as a tuple of
+   the RGB values, each in the range [0..1].  For the third form, the color is
+   specified giving the RGB values as three separate parameters (each in the range
+   [0..1]).
+
+
+.. function:: write(text[, move])
+
+   Write *text* at the current pen position. If *move* is true, the pen is moved to
+   the bottom-right corner of the text. By default, *move* is false.
+
+
+.. function:: fill(flag)
+
+   The complete specifications are rather complex, but the recommended  usage is:
+   call ``fill(1)`` before drawing a path you want to fill, and call ``fill(0)``
+   when you finish to draw the path.
+
+
+.. function:: begin_fill()
+
+   Switch turtle into filling mode;  Must eventually be followed by a corresponding
+   end_fill() call. Otherwise it will be ignored.
+
+   .. versionadded:: 2.5
+
+
+.. function:: end_fill()
+
+   End filling mode, and fill the shape; equivalent to ``fill(0)``.
+
+   .. versionadded:: 2.5
+
+
+.. function:: circle(radius[, extent])
+
+   Draw a circle with radius *radius* whose center-point is *radius* units left of
+   the turtle. *extent* determines which part of a circle is drawn: if not given it
+   defaults to a full circle.
+
+   If *extent* is not a full circle, one endpoint of the arc is the current pen
+   position. The arc is drawn in a counter clockwise direction if *radius* is
+   positive, otherwise in a clockwise direction.  In the process, the direction of
+   the turtle is changed by the amount of the *extent*.
+
+
+.. function:: goto(x, y)
+              goto((x, y))
+
+   Go to co-ordinates *x*, *y*.  The co-ordinates may be specified either as two
+   separate arguments or as a 2-tuple.
+
+
+.. function:: towards(x, y)
+
+   Return the angle of the line from the turtle's position to the point *x*, *y*.
+   The co-ordinates may be specified either as two separate arguments, as a
+   2-tuple, or as another pen object.
+
+   .. versionadded:: 2.5
+
+
+.. function:: heading()
+
+   Return the current orientation of the turtle.
+
+   .. versionadded:: 2.3
+
+
+.. function:: setheading(angle)
+
+   Set the orientation of the turtle to *angle*.
+
+   .. versionadded:: 2.3
+
+
+.. function:: position()
+
+   Return the current location of the turtle as an ``(x,y)`` pair.
+
+   .. versionadded:: 2.3
+
+
+.. function:: setx(x)
+
+   Set the x coordinate of the turtle to *x*.
+
+   .. versionadded:: 2.3
+
+
+.. function:: sety(y)
+
+   Set the y coordinate of the turtle to *y*.
+
+   .. versionadded:: 2.3
+
+
+.. function:: window_width()
+
+   Return the width of the canvas window.
+
+   .. versionadded:: 2.3
+
+
+.. function:: window_height()
+
+   Return the height of the canvas window.
+
+   .. versionadded:: 2.3
+
+This module also does ``from math import *``, so see the documentation for the
+:mod:`math` module for additional constants and functions useful for turtle
+graphics.
+
+
+.. function:: demo()
+
+   Exercise the module a bit.
+
+
+.. exception:: Error
+
+   Exception raised on any error caught by this module.
+
+For examples, see the code of the :func:`demo` function.
+
+This module defines the following classes:
+
+
+.. class:: Pen()
+
+   Define a pen. All above functions can be called as a methods on the given pen.
+   The constructor automatically creates a canvas do be drawn on.
+
+
+.. class:: Turtle()
+
+   Define a pen. This is essentially a synonym for ``Pen()``; :class:`Turtle` is an
+   empty subclass of :class:`Pen`.
+
+
+.. class:: RawPen(canvas)
+
+   Define a pen which draws on a canvas *canvas*. This is useful if  you want to
+   use the module to create graphics in a "real" program.
+
+
+.. _pen-rawpen-objects:
+
+Turtle, Pen and RawPen Objects
+------------------------------
+
+Most of the global functions available in the module are also available as
+methods of the :class:`Turtle`, :class:`Pen` and :class:`RawPen` classes,
+affecting only the state of the given pen.
+
+The only method which is more powerful as a method is :func:`degrees`, which
+takes an optional argument letting  you specify the number of units
+corresponding to a full circle:
+
+
+.. method:: Turtle.degrees([fullcircle])
+
+   *fullcircle* is by default 360. This can cause the pen to have any angular units
+   whatever: give *fullcircle* 2\*$π for radians, or 400 for gradians.
+
diff --git a/Doc/library/types.rst b/Doc/library/types.rst
new file mode 100644
index 0000000..c636a73
--- /dev/null
+++ b/Doc/library/types.rst
@@ -0,0 +1,257 @@
+
+:mod:`types` --- Names for built-in types
+=========================================
+
+.. module:: types
+   :synopsis: Names for built-in types.
+
+
+This module defines names for some object types that are used by the standard
+Python interpreter, but not for the types defined by various extension modules.
+Also, it does not include some of the types that arise during processing such as
+the ``listiterator`` type. It is safe to use ``from types import *`` --- the
+module does not export any names besides the ones listed here. New names
+exported by future versions of this module will all end in ``Type``.
+
+Typical use is for functions that do different things depending on their
+argument types, like the following::
+
+   from types import *
+   def delete(mylist, item):
+       if type(item) is IntType:
+          del mylist[item]
+       else:
+          mylist.remove(item)
+
+Starting in Python 2.2, built-in factory functions such as :func:`int` and
+:func:`str` are also names for the corresponding types.  This is now the
+preferred way to access the type instead of using the :mod:`types` module.
+Accordingly, the example above should be written as follows::
+
+   def delete(mylist, item):
+       if isinstance(item, int):
+          del mylist[item]
+       else:
+          mylist.remove(item)
+
+The module defines the following names:
+
+
+.. data:: NoneType
+
+   The type of ``None``.
+
+
+.. data:: TypeType
+
+   .. index:: builtin: type
+
+   The type of type objects (such as returned by :func:`type`); alias of the
+   built-in :class:`type`.
+
+
+.. data:: BooleanType
+
+   The type of the :class:`bool` values ``True`` and ``False``; alias of the
+   built-in :class:`bool`.
+
+   .. versionadded:: 2.3
+
+
+.. data:: IntType
+
+   The type of integers (e.g. ``1``); alias of the built-in :class:`int`.
+
+
+.. data:: LongType
+
+   The type of long integers (e.g. ``1L``); alias of the built-in :class:`long`.
+
+
+.. data:: FloatType
+
+   The type of floating point numbers (e.g. ``1.0``); alias of the built-in
+   :class:`float`.
+
+
+.. data:: ComplexType
+
+   The type of complex numbers (e.g. ``1.0j``).  This is not defined if Python was
+   built without complex number support.
+
+
+.. data:: StringType
+
+   The type of character strings (e.g. ``'Spam'``); alias of the built-in
+   :class:`str`.
+
+
+.. data:: UnicodeType
+
+   The type of Unicode character strings (e.g. ``u'Spam'``).  This is not defined
+   if Python was built without Unicode support.  It's an alias of the built-in
+   :class:`unicode`.
+
+
+.. data:: TupleType
+
+   The type of tuples (e.g. ``(1, 2, 3, 'Spam')``); alias of the built-in
+   :class:`tuple`.
+
+
+.. data:: ListType
+
+   The type of lists (e.g. ``[0, 1, 2, 3]``); alias of the built-in
+   :class:`list`.
+
+
+.. data:: DictType
+
+   The type of dictionaries (e.g. ``{'Bacon': 1, 'Ham': 0}``); alias of the
+   built-in :class:`dict`.
+
+
+.. data:: DictionaryType
+
+   An alternate name for ``DictType``.
+
+
+.. data:: FunctionType
+
+   The type of user-defined functions and lambdas.
+
+
+.. data:: LambdaType
+
+   An alternate name for ``FunctionType``.
+
+
+.. data:: GeneratorType
+
+   The type of generator-iterator objects, produced by calling a generator
+   function.
+
+   .. versionadded:: 2.2
+
+
+.. data:: CodeType
+
+   .. index:: builtin: compile
+
+   The type for code objects such as returned by :func:`compile`.
+
+
+.. data:: ClassType
+
+   The type of user-defined classes.
+
+
+.. data:: MethodType
+
+   The type of methods of user-defined class instances.
+
+
+.. data:: UnboundMethodType
+
+   An alternate name for ``MethodType``.
+
+
+.. data:: BuiltinFunctionType
+
+   The type of built-in functions like :func:`len` or :func:`sys.exit`.
+
+
+.. data:: BuiltinMethodType
+
+   An alternate name for ``BuiltinFunction``.
+
+
+.. data:: ModuleType
+
+   The type of modules.
+
+
+.. data:: FileType
+
+   The type of open file objects such as ``sys.stdout``; alias of the built-in
+   :class:`file`.
+
+
+.. data:: RangeType
+
+   .. index:: builtin: range
+
+   The type of range objects returned by :func:`range`; alias of the built-in
+   :class:`range`.
+
+
+.. data:: SliceType
+
+   .. index:: builtin: slice
+
+   The type of objects returned by :func:`slice`; alias of the built-in
+   :class:`slice`.
+
+
+.. data:: EllipsisType
+
+   The type of ``Ellipsis``.
+
+
+.. data:: TracebackType
+
+   The type of traceback objects such as found in ``sys.exc_info()[2]``.
+
+
+.. data:: FrameType
+
+   The type of frame objects such as found in ``tb.tb_frame`` if ``tb`` is a
+   traceback object.
+
+
+.. data:: BufferType
+
+   .. index:: builtin: buffer
+
+   The type of buffer objects created by the :func:`buffer` function.
+
+
+.. data:: DictProxyType
+
+   The type of dict proxies, such as ``TypeType.__dict__``.
+
+
+.. data:: NotImplementedType
+
+   The type of ``NotImplemented``
+
+
+.. data:: GetSetDescriptorType
+
+   The type of objects defined in extension modules with ``PyGetSetDef``, such as
+   ``FrameType.f_locals`` or ``array.array.typecode``.  This constant is not
+   defined in implementations of Python that do not have such extension types, so
+   for portable code use ``hasattr(types, 'GetSetDescriptorType')``.
+
+   .. versionadded:: 2.5
+
+
+.. data:: MemberDescriptorType
+
+   The type of objects defined in extension modules with ``PyMemberDef``, such as
+   ``datetime.timedelta.days``.  This constant is not defined in implementations of
+   Python that do not have such extension types, so for portable code use
+   ``hasattr(types, 'MemberDescriptorType')``.
+
+   .. versionadded:: 2.5
+
+
+.. data:: StringTypes
+
+   A sequence containing ``StringType`` and ``UnicodeType`` used to facilitate
+   easier checking for any string object.  Using this is more portable than using a
+   sequence of the two string types constructed elsewhere since it only contains
+   ``UnicodeType`` if it has been built in the running version of Python.  For
+   example: ``isinstance(s, types.StringTypes)``.
+
+   .. versionadded:: 2.2
diff --git a/Doc/library/undoc.rst b/Doc/library/undoc.rst
new file mode 100644
index 0000000..ad46fc8
--- /dev/null
+++ b/Doc/library/undoc.rst
@@ -0,0 +1,186 @@
+
+.. _undoc:
+
+********************
+Undocumented Modules
+********************
+
+Here's a quick listing of modules that are currently undocumented, but that
+should be documented.  Feel free to contribute documentation for them!  (Send
+via email to docs@python.org.)
+
+The idea and original contents for this chapter were taken from a posting by
+Fredrik Lundh; the specific contents of this chapter have been substantially
+revised.
+
+
+Miscellaneous useful utilities
+==============================
+
+Some of these are very old and/or not very robust; marked with "hmm."
+
+:mod:`bdb`
+   --- A generic Python debugger base class (used by pdb).
+
+:mod:`ihooks`
+   --- Import hook support (for :mod:`rexec`; may become obsolete).
+
+
+Platform specific modules
+=========================
+
+These modules are used to implement the :mod:`os.path` module, and are not
+documented beyond this mention.  There's little need to document these.
+
+:mod:`ntpath`
+   --- Implementation of :mod:`os.path` on Win32, Win64, WinCE, and OS/2 platforms.
+
+:mod:`posixpath`
+   --- Implementation of :mod:`os.path` on POSIX.
+
+
+Multimedia
+==========
+
+:mod:`linuxaudiodev`
+   --- Play audio data on the Linux audio device.  Replaced in Python 2.3 by the
+   :mod:`ossaudiodev` module.
+
+:mod:`sunaudio`
+   --- Interpret Sun audio headers (may become obsolete or a tool/demo).
+
+
+.. _undoc-mac-modules:
+
+Undocumented Mac OS modules
+===========================
+
+
+:mod:`applesingle` --- AppleSingle decoder
+------------------------------------------
+
+.. module:: applesingle
+   :platform: Mac
+   :synopsis: Rudimentary decoder for AppleSingle format files.
+
+
+
+:mod:`buildtools` --- Helper module for BuildApplet and Friends
+---------------------------------------------------------------
+
+.. module:: buildtools
+   :platform: Mac
+   :synopsis: Helper module for BuildApplet, BuildApplication and macfreeze.
+
+
+.. deprecated:: 2.4
+
+
+:mod:`icopen` --- Internet Config replacement for :meth:`open`
+--------------------------------------------------------------
+
+.. module:: icopen
+   :platform: Mac
+   :synopsis: Internet Config replacement for open().
+
+
+Importing :mod:`icopen` will replace the builtin :meth:`open` with a version
+that uses Internet Config to set file type and creator for new files.
+
+
+:mod:`macerrors` --- Mac OS Errors
+----------------------------------
+
+.. module:: macerrors
+   :platform: Mac
+   :synopsis: Constant definitions for many Mac OS error codes.
+
+
+:mod:`macerrors` contains constant definitions for many Mac OS error codes.
+
+
+:mod:`macresource` --- Locate script resources
+----------------------------------------------
+
+.. module:: macresource
+   :platform: Mac
+   :synopsis: Locate script resources.
+
+
+:mod:`macresource` helps scripts finding their resources, such as dialogs and
+menus, without requiring special case code for when the script is run under
+MacPython, as a MacPython applet or under OSX Python.
+
+
+:mod:`Nav` --- NavServices calls
+--------------------------------
+
+.. module:: Nav
+   :platform: Mac
+   :synopsis: Interface to Navigation Services.
+
+
+A low-level interface to Navigation Services.
+
+
+:mod:`PixMapWrapper` --- Wrapper for PixMap objects
+---------------------------------------------------
+
+.. module:: PixMapWrapper
+   :platform: Mac
+   :synopsis: Wrapper for PixMap objects.
+
+
+:mod:`PixMapWrapper` wraps a PixMap object with a Python object that allows
+access to the fields by name. It also has methods to convert to and from
+:mod:`PIL` images.
+
+
+:mod:`videoreader` --- Read QuickTime movies
+--------------------------------------------
+
+.. module:: videoreader
+   :platform: Mac
+   :synopsis: Read QuickTime movies frame by frame for further processing.
+
+
+:mod:`videoreader` reads and decodes QuickTime movies and passes a stream of
+images to your program. It also provides some support for audio tracks.
+
+
+:mod:`W` --- Widgets built on :mod:`FrameWork`
+----------------------------------------------
+
+.. module:: W
+   :platform: Mac
+   :synopsis: Widgets for the Mac, built on top of FrameWork.
+
+
+The :mod:`W` widgets are used extensively in the :program:`IDE`.
+
+
+.. _obsolete-modules:
+
+Obsolete
+========
+
+These modules are not normally available for import; additional work must be
+done to make them available.
+
+These extension modules written in C are not built by default. Under Unix, these
+must be enabled by uncommenting the appropriate lines in :file:`Modules/Setup`
+in the build tree and either rebuilding Python if the modules are statically
+linked, or building and installing the shared object if using dynamically-loaded
+extensions.
+
+.. % %% lib-old is empty as of Python 2.5
+.. % Those which are written in Python will be installed into the directory
+.. % \file{lib-old/} installed as part of the standard library.  To use
+.. % these, the directory must be added to \code{sys.path}, possibly using
+.. % \envvar{PYTHONPATH}.
+
+.. % XXX need Windows instructions!
+
+
+   --- This section should be empty for Python 3.0.
+
diff --git a/Doc/library/unicodedata.rst b/Doc/library/unicodedata.rst
new file mode 100644
index 0000000..017d4ee
--- /dev/null
+++ b/Doc/library/unicodedata.rst
@@ -0,0 +1,165 @@
+
+:mod:`unicodedata` --- Unicode Database
+=======================================
+
+.. module:: unicodedata
+   :synopsis: Access the Unicode Database.
+.. moduleauthor:: Marc-Andre Lemburg <mal@lemburg.com>
+.. sectionauthor:: Marc-Andre Lemburg <mal@lemburg.com>
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+
+
+.. index::
+   single: Unicode
+   single: character
+   pair: Unicode; database
+
+This module provides access to the Unicode Character Database which defines
+character properties for all Unicode characters. The data in this database is
+based on the :file:`UnicodeData.txt` file version 4.1.0 which is publicly
+available from ftp://ftp.unicode.org/.
+
+The module uses the same names and symbols as defined by the UnicodeData File
+Format 4.1.0 (see http://www.unicode.org/Public/4.1.0/ucd/UCD.html).  It defines
+the following functions:
+
+
+.. function:: lookup(name)
+
+   Look up character by name.  If a character with the given name is found, return
+   the corresponding Unicode character.  If not found, :exc:`KeyError` is raised.
+
+
+.. function:: name(unichr[, default])
+
+   Returns the name assigned to the Unicode character *unichr* as a string. If no
+   name is defined, *default* is returned, or, if not given, :exc:`ValueError` is
+   raised.
+
+
+.. function:: decimal(unichr[, default])
+
+   Returns the decimal value assigned to the Unicode character *unichr* as integer.
+   If no such value is defined, *default* is returned, or, if not given,
+   :exc:`ValueError` is raised.
+
+
+.. function:: digit(unichr[, default])
+
+   Returns the digit value assigned to the Unicode character *unichr* as integer.
+   If no such value is defined, *default* is returned, or, if not given,
+   :exc:`ValueError` is raised.
+
+
+.. function:: numeric(unichr[, default])
+
+   Returns the numeric value assigned to the Unicode character *unichr* as float.
+   If no such value is defined, *default* is returned, or, if not given,
+   :exc:`ValueError` is raised.
+
+
+.. function:: category(unichr)
+
+   Returns the general category assigned to the Unicode character *unichr* as
+   string.
+
+
+.. function:: bidirectional(unichr)
+
+   Returns the bidirectional category assigned to the Unicode character *unichr* as
+   string. If no such value is defined, an empty string is returned.
+
+
+.. function:: combining(unichr)
+
+   Returns the canonical combining class assigned to the Unicode character *unichr*
+   as integer. Returns ``0`` if no combining class is defined.
+
+
+.. function:: east_asian_width(unichr)
+
+   Returns the east asian width assigned to the Unicode character *unichr* as
+   string.
+
+   .. versionadded:: 2.4
+
+
+.. function:: mirrored(unichr)
+
+   Returns the mirrored property assigned to the Unicode character *unichr* as
+   integer. Returns ``1`` if the character has been identified as a "mirrored"
+   character in bidirectional text, ``0`` otherwise.
+
+
+.. function:: decomposition(unichr)
+
+   Returns the character decomposition mapping assigned to the Unicode character
+   *unichr* as string. An empty string is returned in case no such mapping is
+   defined.
+
+
+.. function:: normalize(form, unistr)
+
+   Return the normal form *form* for the Unicode string *unistr*. Valid values for
+   *form* are 'NFC', 'NFKC', 'NFD', and 'NFKD'.
+
+   The Unicode standard defines various normalization forms of a Unicode string,
+   based on the definition of canonical equivalence and compatibility equivalence.
+   In Unicode, several characters can be expressed in various way. For example, the
+   character U+00C7 (LATIN CAPITAL LETTER C WITH CEDILLA) can also be expressed as
+   the sequence U+0043 (LATIN CAPITAL LETTER C) U+0327 (COMBINING CEDILLA).
+
+   For each character, there are two normal forms: normal form C and normal form D.
+   Normal form D (NFD) is also known as canonical decomposition, and translates
+   each character into its decomposed form. Normal form C (NFC) first applies a
+   canonical decomposition, then composes pre-combined characters again.
+
+   In addition to these two forms, there are two additional normal forms based on
+   compatibility equivalence. In Unicode, certain characters are supported which
+   normally would be unified with other characters. For example, U+2160 (ROMAN
+   NUMERAL ONE) is really the same thing as U+0049 (LATIN CAPITAL LETTER I).
+   However, it is supported in Unicode for compatibility with existing character
+   sets (e.g. gb2312).
+
+   The normal form KD (NFKD) will apply the compatibility decomposition, i.e.
+   replace all compatibility characters with their equivalents. The normal form KC
+   (NFKC) first applies the compatibility decomposition, followed by the canonical
+   composition.
+
+   .. versionadded:: 2.3
+
+In addition, the module exposes the following constant:
+
+
+.. data:: unidata_version
+
+   The version of the Unicode database used in this module.
+
+   .. versionadded:: 2.3
+
+
+.. data:: ucd_3_2_0
+
+   This is an object that has the same methods as the entire module, but uses the
+   Unicode database version 3.2 instead, for applications that require this
+   specific version of the Unicode database (such as IDNA).
+
+   .. versionadded:: 2.5
+
+Examples::
+
+   >>> unicodedata.lookup('LEFT CURLY BRACKET')
+   u'{'
+   >>> unicodedata.name(u'/')
+   'SOLIDUS'
+   >>> unicodedata.decimal(u'9')
+   9
+   >>> unicodedata.decimal(u'a')
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   ValueError: not a decimal
+   >>> unicodedata.category(u'A')  # 'L'etter, 'u'ppercase
+   'Lu'   
+   >>> unicodedata.bidirectional(u'\u0660') # 'A'rabic, 'N'umber
+   'AN'
+
diff --git a/Doc/library/unittest.rst b/Doc/library/unittest.rst
new file mode 100644
index 0000000..3d3727f
--- /dev/null
+++ b/Doc/library/unittest.rst
@@ -0,0 +1,936 @@
+
+:mod:`unittest` --- Unit testing framework
+==========================================
+
+.. module:: unittest
+   :synopsis: Unit testing framework for Python.
+.. moduleauthor:: Steve Purcell <stephen_purcell@yahoo.com>
+.. sectionauthor:: Steve Purcell <stephen_purcell@yahoo.com>
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+.. sectionauthor:: Raymond Hettinger <python@rcn.com>
+
+
+.. versionadded:: 2.1
+
+The Python unit testing framework, sometimes referred to as "PyUnit," is a
+Python language version of JUnit, by Kent Beck and Erich Gamma. JUnit is, in
+turn, a Java version of Kent's Smalltalk testing framework.  Each is the de
+facto standard unit testing framework for its respective language.
+
+:mod:`unittest` supports test automation, sharing of setup and shutdown code for
+tests, aggregation of tests into collections, and independence of the tests from
+the reporting framework.  The :mod:`unittest` module provides classes that make
+it easy to support these qualities for a set of tests.
+
+To achieve this, :mod:`unittest` supports some important concepts:
+
+test fixture
+   A :dfn:`test fixture` represents the preparation needed to perform one or more
+   tests, and any associate cleanup actions.  This may involve, for example,
+   creating temporary or proxy databases, directories, or starting a server
+   process.
+
+test case
+   A :dfn:`test case` is the smallest unit of testing.  It checks for a specific
+   response to a particular set of inputs.  :mod:`unittest` provides a base class,
+   :class:`TestCase`, which may be used to create new test cases.
+
+test suite
+   A :dfn:`test suite` is a collection of test cases, test suites, or both.  It is
+   used to aggregate tests that should be executed together.
+
+test runner
+   A :dfn:`test runner` is a component which orchestrates the execution of tests
+   and provides the outcome to the user.  The runner may use a graphical interface,
+   a textual interface, or return a special value to indicate the results of
+   executing the tests.
+
+The test case and test fixture concepts are supported through the
+:class:`TestCase` and :class:`FunctionTestCase` classes; the former should be
+used when creating new tests, and the latter can be used when integrating
+existing test code with a :mod:`unittest`\ -driven framework. When building test
+fixtures using :class:`TestCase`, the :meth:`setUp` and :meth:`tearDown` methods
+can be overridden to provide initialization and cleanup for the fixture.  With
+:class:`FunctionTestCase`, existing functions can be passed to the constructor
+for these purposes.  When the test is run, the fixture initialization is run
+first; if it succeeds, the cleanup method is run after the test has been
+executed, regardless of the outcome of the test.  Each instance of the
+:class:`TestCase` will only be used to run a single test method, so a new
+fixture is created for each test.
+
+Test suites are implemented by the :class:`TestSuite` class.  This class allows
+individual tests and test suites to be aggregated; when the suite is executed,
+all tests added directly to the suite and in "child" test suites are run.
+
+A test runner is an object that provides a single method, :meth:`run`, which
+accepts a :class:`TestCase` or :class:`TestSuite` object as a parameter, and
+returns a result object.  The class :class:`TestResult` is provided for use as
+the result object. :mod:`unittest` provides the :class:`TextTestRunner` as an
+example test runner which reports test results on the standard error stream by
+default.  Alternate runners can be implemented for other environments (such as
+graphical environments) without any need to derive from a specific class.
+
+
+.. seealso::
+
+   Module :mod:`doctest`
+      Another test-support module with a very different flavor.
+
+   `Simple Smalltalk Testing: With Patterns <http://www.XProgramming.com/testfram.htm>`_
+      Kent Beck's original paper on testing frameworks using the pattern shared by
+      :mod:`unittest`.
+
+
+.. _unittest-minimal-example:
+
+Basic example
+-------------
+
+The :mod:`unittest` module provides a rich set of tools for constructing and
+running tests.  This section demonstrates that a small subset of the tools
+suffice to meet the needs of most users.
+
+Here is a short script to test three functions from the :mod:`random` module::
+
+   import random
+   import unittest
+
+   class TestSequenceFunctions(unittest.TestCase):
+
+       def setUp(self):
+           self.seq = range(10)
+
+       def testshuffle(self):
+           # make sure the shuffled sequence does not lose any elements
+           random.shuffle(self.seq)
+           self.seq.sort()
+           self.assertEqual(self.seq, range(10))
+
+       def testchoice(self):
+           element = random.choice(self.seq)
+           self.assert_(element in self.seq)
+
+       def testsample(self):
+           self.assertRaises(ValueError, random.sample, self.seq, 20)
+           for element in random.sample(self.seq, 5):
+               self.assert_(element in self.seq)
+
+   if __name__ == '__main__':
+       unittest.main()
+
+A testcase is created by subclassing :class:`unittest.TestCase`. The three
+individual tests are defined with methods whose names start with the letters
+``test``.  This naming convention informs the test runner about which methods
+represent tests.
+
+The crux of each test is a call to :meth:`assertEqual` to check for an expected
+result; :meth:`assert_` to verify a condition; or :meth:`assertRaises` to verify
+that an expected exception gets raised.  These methods are used instead of the
+:keyword:`assert` statement so the test runner can accumulate all test results
+and produce a report.
+
+When a :meth:`setUp` method is defined, the test runner will run that method
+prior to each test.  Likewise, if a :meth:`tearDown` method is defined, the test
+runner will invoke that method after each test.  In the example, :meth:`setUp`
+was used to create a fresh sequence for each test.
+
+The final block shows a simple way to run the tests. :func:`unittest.main`
+provides a command line interface to the test script.  When run from the command
+line, the above script produces an output that looks like this::
+
+   ...
+   ----------------------------------------------------------------------
+   Ran 3 tests in 0.000s
+
+   OK
+
+Instead of :func:`unittest.main`, there are other ways to run the tests with a
+finer level of control, less terse output, and no requirement to be run from the
+command line.  For example, the last two lines may be replaced with::
+
+   suite = unittest.TestLoader().loadTestsFromTestCase(TestSequenceFunctions)
+   unittest.TextTestRunner(verbosity=2).run(suite)
+
+Running the revised script from the interpreter or another script produces the
+following output::
+
+   testchoice (__main__.TestSequenceFunctions) ... ok
+   testsample (__main__.TestSequenceFunctions) ... ok
+   testshuffle (__main__.TestSequenceFunctions) ... ok
+
+   ----------------------------------------------------------------------
+   Ran 3 tests in 0.110s
+
+   OK
+
+The above examples show the most commonly used :mod:`unittest` features which
+are sufficient to meet many everyday testing needs.  The remainder of the
+documentation explores the full feature set from first principles.
+
+
+.. _organizing-tests:
+
+Organizing test code
+--------------------
+
+The basic building blocks of unit testing are :dfn:`test cases` --- single
+scenarios that must be set up and checked for correctness.  In :mod:`unittest`,
+test cases are represented by instances of :mod:`unittest`'s :class:`TestCase`
+class. To make your own test cases you must write subclasses of
+:class:`TestCase`, or use :class:`FunctionTestCase`.
+
+An instance of a :class:`TestCase`\ -derived class is an object that can
+completely run a single test method, together with optional set-up and tidy-up
+code.
+
+The testing code of a :class:`TestCase` instance should be entirely self
+contained, such that it can be run either in isolation or in arbitrary
+combination with any number of other test cases.
+
+The simplest :class:`TestCase` subclass will simply override the :meth:`runTest`
+method in order to perform specific testing code::
+
+   import unittest
+
+   class DefaultWidgetSizeTestCase(unittest.TestCase):
+       def runTest(self):
+           widget = Widget('The widget')
+           self.assertEqual(widget.size(), (50, 50), 'incorrect default size')
+
+Note that in order to test something, we use the one of the :meth:`assert\*` or
+:meth:`fail\*` methods provided by the :class:`TestCase` base class.  If the
+test fails, an exception will be raised, and :mod:`unittest` will identify the
+test case as a :dfn:`failure`.  Any other exceptions will be treated as
+:dfn:`errors`. This helps you identify where the problem is: :dfn:`failures` are
+caused by incorrect results - a 5 where you expected a 6. :dfn:`Errors` are
+caused by incorrect code - e.g., a :exc:`TypeError` caused by an incorrect
+function call.
+
+The way to run a test case will be described later.  For now, note that to
+construct an instance of such a test case, we call its constructor without
+arguments::
+
+   testCase = DefaultWidgetSizeTestCase()
+
+Now, such test cases can be numerous, and their set-up can be repetitive.  In
+the above case, constructing a :class:`Widget` in each of 100 Widget test case
+subclasses would mean unsightly duplication.
+
+Luckily, we can factor out such set-up code by implementing a method called
+:meth:`setUp`, which the testing framework will automatically call for us when
+we run the test::
+
+   import unittest
+
+   class SimpleWidgetTestCase(unittest.TestCase):
+       def setUp(self):
+           self.widget = Widget('The widget')
+
+   class DefaultWidgetSizeTestCase(SimpleWidgetTestCase):
+       def runTest(self):
+           self.failUnless(self.widget.size() == (50,50),
+                           'incorrect default size')
+
+   class WidgetResizeTestCase(SimpleWidgetTestCase):
+       def runTest(self):
+           self.widget.resize(100,150)
+           self.failUnless(self.widget.size() == (100,150),
+                           'wrong size after resize')
+
+If the :meth:`setUp` method raises an exception while the test is running, the
+framework will consider the test to have suffered an error, and the
+:meth:`runTest` method will not be executed.
+
+Similarly, we can provide a :meth:`tearDown` method that tidies up after the
+:meth:`runTest` method has been run::
+
+   import unittest
+
+   class SimpleWidgetTestCase(unittest.TestCase):
+       def setUp(self):
+           self.widget = Widget('The widget')
+
+       def tearDown(self):
+           self.widget.dispose()
+           self.widget = None
+
+If :meth:`setUp` succeeded, the :meth:`tearDown` method will be run whether
+:meth:`runTest` succeeded or not.
+
+Such a working environment for the testing code is called a :dfn:`fixture`.
+
+Often, many small test cases will use the same fixture.  In this case, we would
+end up subclassing :class:`SimpleWidgetTestCase` into many small one-method
+classes such as :class:`DefaultWidgetSizeTestCase`.  This is time-consuming and
+
+discouraging, so in the same vein as JUnit, :mod:`unittest` provides a simpler
+mechanism::
+
+   import unittest
+
+   class WidgetTestCase(unittest.TestCase):
+       def setUp(self):
+           self.widget = Widget('The widget')
+
+       def tearDown(self):
+           self.widget.dispose()
+           self.widget = None
+
+       def testDefaultSize(self):
+           self.failUnless(self.widget.size() == (50,50),
+                           'incorrect default size')
+
+       def testResize(self):
+           self.widget.resize(100,150)
+           self.failUnless(self.widget.size() == (100,150),
+                           'wrong size after resize')
+
+Here we have not provided a :meth:`runTest` method, but have instead provided
+two different test methods.  Class instances will now each run one of the
+:meth:`test\*`  methods, with ``self.widget`` created and destroyed separately
+for each instance.  When creating an instance we must specify the test method it
+is to run.  We do this by passing the method name in the constructor::
+
+   defaultSizeTestCase = WidgetTestCase('testDefaultSize')
+   resizeTestCase = WidgetTestCase('testResize')
+
+Test case instances are grouped together according to the features they test.
+:mod:`unittest` provides a mechanism for this: the :dfn:`test suite`,
+represented by :mod:`unittest`'s :class:`TestSuite` class::
+
+   widgetTestSuite = unittest.TestSuite()
+   widgetTestSuite.addTest(WidgetTestCase('testDefaultSize'))
+   widgetTestSuite.addTest(WidgetTestCase('testResize'))
+
+For the ease of running tests, as we will see later, it is a good idea to
+provide in each test module a callable object that returns a pre-built test
+suite::
+
+   def suite():
+       suite = unittest.TestSuite()
+       suite.addTest(WidgetTestCase('testDefaultSize'))
+       suite.addTest(WidgetTestCase('testResize'))
+       return suite
+
+or even::
+
+   def suite():
+       tests = ['testDefaultSize', 'testResize']
+
+       return unittest.TestSuite(map(WidgetTestCase, tests))
+
+Since it is a common pattern to create a :class:`TestCase` subclass with many
+similarly named test functions, :mod:`unittest` provides a :class:`TestLoader`
+class that can be used to automate the process of creating a test suite and
+populating it with individual tests. For example, ::
+
+   suite = unittest.TestLoader().loadTestsFromTestCase(WidgetTestCase)
+
+will create a test suite that will run ``WidgetTestCase.testDefaultSize()`` and
+``WidgetTestCase.testResize``. :class:`TestLoader` uses the ``'test'`` method
+name prefix to identify test methods automatically.
+
+Note that the order in which the various test cases will be run is determined by
+sorting the test function names with the built-in :func:`cmp` function.
+
+Often it is desirable to group suites of test cases together, so as to run tests
+for the whole system at once.  This is easy, since :class:`TestSuite` instances
+can be added to a :class:`TestSuite` just as :class:`TestCase` instances can be
+added to a :class:`TestSuite`::
+
+   suite1 = module1.TheTestSuite()
+   suite2 = module2.TheTestSuite()
+   alltests = unittest.TestSuite([suite1, suite2])
+
+You can place the definitions of test cases and test suites in the same modules
+as the code they are to test (such as :file:`widget.py`), but there are several
+advantages to placing the test code in a separate module, such as
+:file:`test_widget.py`:
+
+* The test module can be run standalone from the command line.
+
+* The test code can more easily be separated from shipped code.
+
+* There is less temptation to change test code to fit the code it tests without
+  a good reason.
+
+* Test code should be modified much less frequently than the code it tests.
+
+* Tested code can be refactored more easily.
+
+* Tests for modules written in C must be in separate modules anyway, so why not
+  be consistent?
+
+* If the testing strategy changes, there is no need to change the source code.
+
+
+.. _legacy-unit-tests:
+
+Re-using old test code
+----------------------
+
+Some users will find that they have existing test code that they would like to
+run from :mod:`unittest`, without converting every old test function to a
+:class:`TestCase` subclass.
+
+For this reason, :mod:`unittest` provides a :class:`FunctionTestCase` class.
+This subclass of :class:`TestCase` can be used to wrap an existing test
+function.  Set-up and tear-down functions can also be provided.
+
+Given the following test function::
+
+   def testSomething():
+       something = makeSomething()
+       assert something.name is not None
+       # ...
+
+one can create an equivalent test case instance as follows::
+
+   testcase = unittest.FunctionTestCase(testSomething)
+
+If there are additional set-up and tear-down methods that should be called as
+part of the test case's operation, they can also be provided like so::
+
+   testcase = unittest.FunctionTestCase(testSomething,
+                                        setUp=makeSomethingDB,
+                                        tearDown=deleteSomethingDB)
+
+To make migrating existing test suites easier, :mod:`unittest` supports tests
+raising :exc:`AssertionError` to indicate test failure. However, it is
+recommended that you use the explicit :meth:`TestCase.fail\*` and
+:meth:`TestCase.assert\*` methods instead, as future versions of :mod:`unittest`
+may treat :exc:`AssertionError` differently.
+
+.. note::
+
+   Even though :class:`FunctionTestCase` can be used to quickly convert an existing
+   test base over to a :mod:`unittest`\ -based system, this approach is not
+   recommended.  Taking the time to set up proper :class:`TestCase` subclasses will
+   make future test refactorings infinitely easier.
+
+
+.. _unittest-contents:
+
+Classes and functions
+---------------------
+
+
+.. class:: TestCase([methodName])
+
+   Instances of the :class:`TestCase` class represent the smallest testable units
+   in the :mod:`unittest` universe.  This class is intended to be used as a base
+   class, with specific tests being implemented by concrete subclasses.  This class
+   implements the interface needed by the test runner to allow it to drive the
+   test, and methods that the test code can use to check for and report various
+   kinds of failure.
+
+   Each instance of :class:`TestCase` will run a single test method: the method
+   named *methodName*.  If you remember, we had an earlier example that went
+   something like this::
+
+      def suite():
+          suite = unittest.TestSuite()
+          suite.addTest(WidgetTestCase('testDefaultSize'))
+          suite.addTest(WidgetTestCase('testResize'))
+          return suite
+
+   Here, we create two instances of :class:`WidgetTestCase`, each of which runs a
+   single test.
+
+   *methodName* defaults to ``'runTest'``.
+
+
+.. class:: FunctionTestCase(testFunc[, setUp[, tearDown[, description]]])
+
+   This class implements the portion of the :class:`TestCase` interface which
+   allows the test runner to drive the test, but does not provide the methods which
+   test code can use to check and report errors. This is used to create test cases
+   using legacy test code, allowing it to be integrated into a :mod:`unittest`\
+   -based test framework.
+
+
+.. class:: TestSuite([tests])
+
+   This class represents an aggregation of individual tests cases and test suites.
+   The class presents the interface needed by the test runner to allow it to be run
+   as any other test case.  Running a :class:`TestSuite` instance is the same as
+   iterating over the suite, running each test individually.
+
+   If *tests* is given, it must be an iterable of individual test cases or other
+   test suites that will be used to build the suite initially. Additional methods
+   are provided to add test cases and suites to the collection later on.
+
+
+.. class:: TestLoader()
+
+   This class is responsible for loading tests according to various criteria and
+   returning them wrapped in a :class:`TestSuite`. It can load all tests within a
+   given module or :class:`TestCase` subclass.
+
+
+.. class:: TestResult()
+
+   This class is used to compile information about which tests have succeeded and
+   which have failed.
+
+
+.. data:: defaultTestLoader
+
+   Instance of the :class:`TestLoader` class intended to be shared.  If no
+   customization of the :class:`TestLoader` is needed, this instance can be used
+   instead of repeatedly creating new instances.
+
+
+.. class:: TextTestRunner([stream[, descriptions[, verbosity]]])
+
+   A basic test runner implementation which prints results on standard error.  It
+   has a few configurable parameters, but is essentially very simple.  Graphical
+   applications which run test suites should provide alternate implementations.
+
+
+.. function:: main([module[, defaultTest[, argv[, testRunner[, testLoader]]]]])
+
+   A command-line program that runs a set of tests; this is primarily for making
+   test modules conveniently executable.  The simplest use for this function is to
+   include the following line at the end of a test script::
+
+      if __name__ == '__main__':
+          unittest.main()
+
+   The *testRunner* argument can either be a test runner class or an already
+   created instance of it.
+
+In some cases, the existing tests may have been written using the :mod:`doctest`
+module.  If so, that module provides a  :class:`DocTestSuite` class that can
+automatically build :class:`unittest.TestSuite` instances from the existing
+:mod:`doctest`\ -based tests.
+
+.. versionadded:: 2.3
+
+
+.. _testcase-objects:
+
+TestCase Objects
+----------------
+
+Each :class:`TestCase` instance represents a single test, but each concrete
+subclass may be used to define multiple tests --- the concrete class represents
+a single test fixture.  The fixture is created and cleaned up for each test
+case.
+
+:class:`TestCase` instances provide three groups of methods: one group used to
+run the test, another used by the test implementation to check conditions and
+report failures, and some inquiry methods allowing information about the test
+itself to be gathered.
+
+Methods in the first group (running the test) are:
+
+
+.. method:: TestCase.setUp()
+
+   Method called to prepare the test fixture.  This is called immediately before
+   calling the test method; any exception raised by this method will be considered
+   an error rather than a test failure. The default implementation does nothing.
+
+
+.. method:: TestCase.tearDown()
+
+   Method called immediately after the test method has been called and the result
+   recorded.  This is called even if the test method raised an exception, so the
+   implementation in subclasses may need to be particularly careful about checking
+   internal state.  Any exception raised by this method will be considered an error
+   rather than a test failure.  This method will only be called if the
+   :meth:`setUp` succeeds, regardless of the outcome of the test method. The
+   default implementation does nothing.
+
+
+.. method:: TestCase.run([result])
+
+   Run the test, collecting the result into the test result object passed as
+   *result*.  If *result* is omitted or :const:`None`, a temporary result object is
+   created (by calling the :meth:`defaultTestCase` method) and used; this result
+   object is not returned to :meth:`run`'s caller.
+
+   The same effect may be had by simply calling the :class:`TestCase` instance.
+
+
+.. method:: TestCase.debug()
+
+   Run the test without collecting the result.  This allows exceptions raised by
+   the test to be propagated to the caller, and can be used to support running
+   tests under a debugger.
+
+The test code can use any of the following methods to check for and report
+failures.
+
+
+.. method:: TestCase.assert_(expr[, msg])
+            TestCase.failUnless(expr[, msg])
+
+   Signal a test failure if *expr* is false; the explanation for the error will be
+   *msg* if given, otherwise it will be :const:`None`.
+
+
+.. method:: TestCase.assertEqual(first, second[, msg])
+            TestCase.failUnlessEqual(first, second[, msg])
+
+   Test that *first* and *second* are equal.  If the values do not compare equal,
+   the test will fail with the explanation given by *msg*, or :const:`None`.  Note
+   that using :meth:`failUnlessEqual` improves upon doing the comparison as the
+   first parameter to :meth:`failUnless`:  the default value for *msg* can be
+   computed to include representations of both *first* and *second*.
+
+
+.. method:: TestCase.assertNotEqual(first, second[, msg])
+            TestCase.failIfEqual(first, second[, msg])
+
+   Test that *first* and *second* are not equal.  If the values do compare equal,
+   the test will fail with the explanation given by *msg*, or :const:`None`.  Note
+   that using :meth:`failIfEqual` improves upon doing the comparison as the first
+   parameter to :meth:`failUnless` is that the default value for *msg* can be
+   computed to include representations of both *first* and *second*.
+
+
+.. method:: TestCase.assertAlmostEqual(first, second[, places[, msg]])
+            TestCase.failUnlessAlmostEqual(first, second[, places[, msg]])
+
+   Test that *first* and *second* are approximately equal by computing the
+   difference, rounding to the given number of *places*, and comparing to zero.
+   Note that comparing a given number of decimal places is not the same as
+   comparing a given number of significant digits. If the values do not compare
+   equal, the test will fail with the explanation given by *msg*, or :const:`None`.
+
+
+.. method:: TestCase.assertNotAlmostEqual(first, second[, places[, msg]])
+            TestCase.failIfAlmostEqual(first, second[, places[, msg]])
+
+   Test that *first* and *second* are not approximately equal by computing the
+   difference, rounding to the given number of *places*, and comparing to zero.
+   Note that comparing a given number of decimal places is not the same as
+   comparing a given number of significant digits. If the values do not compare
+   equal, the test will fail with the explanation given by *msg*, or :const:`None`.
+
+
+.. method:: TestCase.assertRaises(exception, callable, ...)
+            TestCase.failUnlessRaises(exception, callable, ...)
+
+   Test that an exception is raised when *callable* is called with any positional
+   or keyword arguments that are also passed to :meth:`assertRaises`.  The test
+   passes if *exception* is raised, is an error if another exception is raised, or
+   fails if no exception is raised.  To catch any of a group of exceptions, a tuple
+   containing the exception classes may be passed as *exception*.
+
+
+.. method:: TestCase.failIf(expr[, msg])
+
+   The inverse of the :meth:`failUnless` method is the :meth:`failIf` method.  This
+   signals a test failure if *expr* is true, with *msg* or :const:`None` for the
+   error message.
+
+
+.. method:: TestCase.fail([msg])
+
+   Signals a test failure unconditionally, with *msg* or :const:`None` for the
+   error message.
+
+
+.. attribute:: TestCase.failureException
+
+   This class attribute gives the exception raised by the :meth:`test` method.  If
+   a test framework needs to use a specialized exception, possibly to carry
+   additional information, it must subclass this exception in order to "play fair"
+   with the framework.  The initial value of this attribute is
+   :exc:`AssertionError`.
+
+Testing frameworks can use the following methods to collect information on the
+test:
+
+
+.. method:: TestCase.countTestCases()
+
+   Return the number of tests represented by this test object.  For
+   :class:`TestCase` instances, this will always be ``1``.
+
+
+.. method:: TestCase.defaultTestResult()
+
+   Return an instance of the test result class that should be used for this test
+   case class (if no other result instance is provided to the :meth:`run` method).
+
+   For :class:`TestCase` instances, this will always be an instance of
+   :class:`TestResult`;  subclasses of :class:`TestCase` should override this as
+   necessary.
+
+
+.. method:: TestCase.id()
+
+   Return a string identifying the specific test case.  This is usually the full
+   name of the test method, including the module and class name.
+
+
+.. method:: TestCase.shortDescription()
+
+   Returns a one-line description of the test, or :const:`None` if no description
+   has been provided.  The default implementation of this method returns the first
+   line of the test method's docstring, if available, or :const:`None`.
+
+
+.. _testsuite-objects:
+
+TestSuite Objects
+-----------------
+
+:class:`TestSuite` objects behave much like :class:`TestCase` objects, except
+they do not actually implement a test.  Instead, they are used to aggregate
+tests into groups of tests that should be run together. Some additional methods
+are available to add tests to :class:`TestSuite` instances:
+
+
+.. method:: TestSuite.addTest(test)
+
+   Add a :class:`TestCase` or :class:`TestSuite` to the suite.
+
+
+.. method:: TestSuite.addTests(tests)
+
+   Add all the tests from an iterable of :class:`TestCase` and :class:`TestSuite`
+   instances to this test suite.
+
+   This is equivalent to iterating over *tests*, calling :meth:`addTest` for each
+   element.
+
+:class:`TestSuite` shares the following methods with :class:`TestCase`:
+
+
+.. method:: TestSuite.run(result)
+
+   Run the tests associated with this suite, collecting the result into the test
+   result object passed as *result*.  Note that unlike :meth:`TestCase.run`,
+   :meth:`TestSuite.run` requires the result object to be passed in.
+
+
+.. method:: TestSuite.debug()
+
+   Run the tests associated with this suite without collecting the result. This
+   allows exceptions raised by the test to be propagated to the caller and can be
+   used to support running tests under a debugger.
+
+
+.. method:: TestSuite.countTestCases()
+
+   Return the number of tests represented by this test object, including all
+   individual tests and sub-suites.
+
+In the typical usage of a :class:`TestSuite` object, the :meth:`run` method is
+invoked by a :class:`TestRunner` rather than by the end-user test harness.
+
+
+.. _testresult-objects:
+
+TestResult Objects
+------------------
+
+A :class:`TestResult` object stores the results of a set of tests.  The
+:class:`TestCase` and :class:`TestSuite` classes ensure that results are
+properly recorded; test authors do not need to worry about recording the outcome
+of tests.
+
+Testing frameworks built on top of :mod:`unittest` may want access to the
+:class:`TestResult` object generated by running a set of tests for reporting
+purposes; a :class:`TestResult` instance is returned by the
+:meth:`TestRunner.run` method for this purpose.
+
+:class:`TestResult` instances have the following attributes that will be of
+interest when inspecting the results of running a set of tests:
+
+
+.. attribute:: TestResult.errors
+
+   A list containing 2-tuples of :class:`TestCase` instances and strings holding
+   formatted tracebacks. Each tuple represents a test which raised an unexpected
+   exception.
+
+   .. versionchanged:: 2.2
+      Contains formatted tracebacks instead of :func:`sys.exc_info` results.
+
+
+.. attribute:: TestResult.failures
+
+   A list containing 2-tuples of :class:`TestCase` instances and strings holding
+   formatted tracebacks. Each tuple represents a test where a failure was
+   explicitly signalled using the :meth:`TestCase.fail\*` or
+   :meth:`TestCase.assert\*` methods.
+
+   .. versionchanged:: 2.2
+      Contains formatted tracebacks instead of :func:`sys.exc_info` results.
+
+
+.. attribute:: TestResult.testsRun
+
+   The total number of tests run so far.
+
+
+.. method:: TestResult.wasSuccessful()
+
+   Returns :const:`True` if all tests run so far have passed, otherwise returns
+   :const:`False`.
+
+
+.. method:: TestResult.stop()
+
+   This method can be called to signal that the set of tests being run should be
+   aborted by setting the :class:`TestResult`'s ``shouldStop`` attribute to
+   :const:`True`.  :class:`TestRunner` objects should respect this flag and return
+   without running any additional tests.
+
+   For example, this feature is used by the :class:`TextTestRunner` class to stop
+   the test framework when the user signals an interrupt from the keyboard.
+   Interactive tools which provide :class:`TestRunner` implementations can use this
+   in a similar manner.
+
+The following methods of the :class:`TestResult` class are used to maintain the
+internal data structures, and may be extended in subclasses to support
+additional reporting requirements.  This is particularly useful in building
+tools which support interactive reporting while tests are being run.
+
+
+.. method:: TestResult.startTest(test)
+
+   Called when the test case *test* is about to be run.
+
+   The default implementation simply increments the instance's ``testsRun``
+   counter.
+
+
+.. method:: TestResult.stopTest(test)
+
+   Called after the test case *test* has been executed, regardless of the outcome.
+
+   The default implementation does nothing.
+
+
+.. method:: TestResult.addError(test, err)
+
+   Called when the test case *test* raises an unexpected exception *err* is a tuple
+   of the form returned by :func:`sys.exc_info`: ``(type, value, traceback)``.
+
+   The default implementation appends ``(test, err)`` to the instance's ``errors``
+   attribute.
+
+
+.. method:: TestResult.addFailure(test, err)
+
+   Called when the test case *test* signals a failure. *err* is a tuple of the form
+   returned by :func:`sys.exc_info`:  ``(type, value, traceback)``.
+
+   The default implementation appends ``(test, err)`` to the instance's
+   ``failures`` attribute.
+
+
+.. method:: TestResult.addSuccess(test)
+
+   Called when the test case *test* succeeds.
+
+   The default implementation does nothing.
+
+
+.. _testloader-objects:
+
+TestLoader Objects
+------------------
+
+The :class:`TestLoader` class is used to create test suites from classes and
+modules.  Normally, there is no need to create an instance of this class; the
+:mod:`unittest` module provides an instance that can be shared as
+``unittest.defaultTestLoader``. Using a subclass or instance, however, allows
+customization of some configurable properties.
+
+:class:`TestLoader` objects have the following methods:
+
+
+.. method:: TestLoader.loadTestsFromTestCase(testCaseClass)
+
+   Return a suite of all tests cases contained in the :class:`TestCase`\ -derived
+   :class:`testCaseClass`.
+
+
+.. method:: TestLoader.loadTestsFromModule(module)
+
+   Return a suite of all tests cases contained in the given module. This method
+   searches *module* for classes derived from :class:`TestCase` and creates an
+   instance of the class for each test method defined for the class.
+
+   .. warning::
+
+      While using a hierarchy of :class:`TestCase`\ -derived classes can be convenient
+      in sharing fixtures and helper functions, defining test methods on base classes
+      that are not intended to be instantiated directly does not play well with this
+      method.  Doing so, however, can be useful when the fixtures are different and
+      defined in subclasses.
+
+
+.. method:: TestLoader.loadTestsFromName(name[, module])
+
+   Return a suite of all tests cases given a string specifier.
+
+   The specifier *name* is a "dotted name" that may resolve either to a module, a
+   test case class, a test method within a test case class, a :class:`TestSuite`
+   instance, or a callable object which returns a :class:`TestCase` or
+   :class:`TestSuite` instance.  These checks are applied in the order listed here;
+   that is, a method on a possible test case class will be picked up as "a test
+   method within a test case class", rather than "a callable object".
+
+   For example, if you have a module :mod:`SampleTests` containing a
+   :class:`TestCase`\ -derived class :class:`SampleTestCase` with three test
+   methods (:meth:`test_one`, :meth:`test_two`, and :meth:`test_three`), the
+   specifier ``'SampleTests.SampleTestCase'`` would cause this method to return a
+   suite which will run all three test methods.  Using the specifier
+   ``'SampleTests.SampleTestCase.test_two'`` would cause it to return a test suite
+   which will run only the :meth:`test_two` test method.  The specifier can refer
+   to modules and packages which have not been imported; they will be imported as a
+   side-effect.
+
+   The method optionally resolves *name* relative to the given *module*.
+
+
+.. method:: TestLoader.loadTestsFromNames(names[, module])
+
+   Similar to :meth:`loadTestsFromName`, but takes a sequence of names rather than
+   a single name.  The return value is a test suite which supports all the tests
+   defined for each name.
+
+
+.. method:: TestLoader.getTestCaseNames(testCaseClass)
+
+   Return a sorted sequence of method names found within *testCaseClass*; this
+   should be a subclass of :class:`TestCase`.
+
+The following attributes of a :class:`TestLoader` can be configured either by
+subclassing or assignment on an instance:
+
+
+.. attribute:: TestLoader.testMethodPrefix
+
+   String giving the prefix of method names which will be interpreted as test
+   methods.  The default value is ``'test'``.
+
+   This affects :meth:`getTestCaseNames` and all the :meth:`loadTestsFrom\*`
+   methods.
+
+
+.. attribute:: TestLoader.sortTestMethodsUsing
+
+   Function to be used to compare method names when sorting them in
+   :meth:`getTestCaseNames` and all the :meth:`loadTestsFrom\*` methods. The
+   default value is the built-in :func:`cmp` function; the attribute can also be
+   set to :const:`None` to disable the sort.
+
+
+.. attribute:: TestLoader.suiteClass
+
+   Callable object that constructs a test suite from a list of tests. No methods on
+   the resulting object are needed.  The default value is the :class:`TestSuite`
+   class.
+
+   This affects all the :meth:`loadTestsFrom\*` methods.
+
diff --git a/Doc/library/unix.rst b/Doc/library/unix.rst
new file mode 100644
index 0000000..b60af0f
--- /dev/null
+++ b/Doc/library/unix.rst
@@ -0,0 +1,29 @@
+
+.. _unix:
+
+**********************
+Unix Specific Services
+**********************
+
+The modules described in this chapter provide interfaces to features that are
+unique to the Unix operating system, or in some cases to some or many variants
+of it.  Here's an overview:
+
+
+.. toctree::
+
+   posix.rst
+   pwd.rst
+   spwd.rst
+   grp.rst
+   crypt.rst
+   dl.rst
+   termios.rst
+   tty.rst
+   pty.rst
+   fcntl.rst
+   pipes.rst
+   resource.rst
+   nis.rst
+   syslog.rst
+   commands.rst
diff --git a/Doc/library/urllib.rst b/Doc/library/urllib.rst
new file mode 100644
index 0000000..ef8264f
--- /dev/null
+++ b/Doc/library/urllib.rst
@@ -0,0 +1,471 @@
+
+:mod:`urllib` --- Open arbitrary resources by URL
+=================================================
+
+.. module:: urllib
+   :synopsis: Open an arbitrary network resource by URL (requires sockets).
+
+
+.. index::
+   single: WWW
+   single: World Wide Web
+   single: URL
+
+This module provides a high-level interface for fetching data across the World
+Wide Web.  In particular, the :func:`urlopen` function is similar to the
+built-in function :func:`open`, but accepts Universal Resource Locators (URLs)
+instead of filenames.  Some restrictions apply --- it can only open URLs for
+reading, and no seek operations are available.
+
+It defines the following public functions:
+
+
+.. function:: urlopen(url[, data[, proxies]])
+
+   Open a network object denoted by a URL for reading.  If the URL does not have a
+   scheme identifier, or if it has :file:`file:` as its scheme identifier, this
+   opens a local file (without universal newlines); otherwise it opens a socket to
+   a server somewhere on the network.  If the connection cannot be made the
+   :exc:`IOError` exception is raised.  If all went well, a file-like object is
+   returned.  This supports the following methods: :meth:`read`, :meth:`readline`,
+   :meth:`readlines`, :meth:`fileno`, :meth:`close`, :meth:`info` and
+   :meth:`geturl`.  It also has proper support for the iterator protocol. One
+   caveat: the :meth:`read` method, if the size argument is omitted or negative,
+   may not read until the end of the data stream; there is no good way to determine
+   that the entire stream from a socket has been read in the general case.
+
+   Except for the :meth:`info` and :meth:`geturl` methods, these methods have the
+   same interface as for file objects --- see section :ref:`bltin-file-objects` in
+   this manual.  (It is not a built-in file object, however, so it can't be used at
+   those few places where a true built-in file object is required.)
+
+   .. index:: module: mimetools
+
+   The :meth:`info` method returns an instance of the class
+   :class:`mimetools.Message` containing meta-information associated with the
+   URL.  When the method is HTTP, these headers are those returned by the server
+   at the head of the retrieved HTML page (including Content-Length and
+   Content-Type).  When the method is FTP, a Content-Length header will be
+   present if (as is now usual) the server passed back a file length in response
+   to the FTP retrieval request. A Content-Type header will be present if the
+   MIME type can be guessed.  When the method is local-file, returned headers
+   will include a Date representing the file's last-modified time, a
+   Content-Length giving file size, and a Content-Type containing a guess at the
+   file's type. See also the description of the :mod:`mimetools` module.
+
+   The :meth:`geturl` method returns the real URL of the page.  In some cases, the
+   HTTP server redirects a client to another URL.  The :func:`urlopen` function
+   handles this transparently, but in some cases the caller needs to know which URL
+   the client was redirected to.  The :meth:`geturl` method can be used to get at
+   this redirected URL.
+
+   If the *url* uses the :file:`http:` scheme identifier, the optional *data*
+   argument may be given to specify a ``POST`` request (normally the request type
+   is ``GET``).  The *data* argument must be in standard
+   :mimetype:`application/x-www-form-urlencoded` format; see the :func:`urlencode`
+   function below.
+
+   The :func:`urlopen` function works transparently with proxies which do not
+   require authentication.  In a Unix or Windows environment, set the
+   :envvar:`http_proxy`, or :envvar:`ftp_proxy` environment variables to a URL that
+   identifies the proxy server before starting the Python interpreter.  For example
+   (the ``'%'`` is the command prompt)::
+
+      % http_proxy="http://www.someproxy.com:3128"
+      % export http_proxy
+      % python
+      ...
+
+   In a Windows environment, if no proxy environment variables are set, proxy
+   settings are obtained from the registry's Internet Settings section.
+
+   .. index:: single: Internet Config
+
+   In a Macintosh environment, :func:`urlopen` will retrieve proxy information from
+   Internet Config.
+
+   Alternatively, the optional *proxies* argument may be used to explicitly specify
+   proxies.  It must be a dictionary mapping scheme names to proxy URLs, where an
+   empty dictionary causes no proxies to be used, and ``None`` (the default value)
+   causes environmental proxy settings to be used as discussed above.  For
+   example::
+
+      # Use http://www.someproxy.com:3128 for http proxying
+      proxies = {'http': 'http://www.someproxy.com:3128'}
+      filehandle = urllib.urlopen(some_url, proxies=proxies)
+      # Don't use any proxies
+      filehandle = urllib.urlopen(some_url, proxies={})
+      # Use proxies from environment - both versions are equivalent
+      filehandle = urllib.urlopen(some_url, proxies=None)
+      filehandle = urllib.urlopen(some_url)
+
+   The :func:`urlopen` function does not support explicit proxy specification.  If
+   you need to override environmental proxy settings, use :class:`URLopener`, or a
+   subclass such as :class:`FancyURLopener`.
+
+   Proxies which require authentication for use are not currently supported; this
+   is considered an implementation limitation.
+
+   .. versionchanged:: 2.3
+      Added the *proxies* support.
+
+
+.. function:: urlretrieve(url[, filename[, reporthook[, data]]])
+
+   Copy a network object denoted by a URL to a local file, if necessary. If the URL
+   points to a local file, or a valid cached copy of the object exists, the object
+   is not copied.  Return a tuple ``(filename, headers)`` where *filename* is the
+   local file name under which the object can be found, and *headers* is whatever
+   the :meth:`info` method of the object returned by :func:`urlopen` returned (for
+   a remote object, possibly cached). Exceptions are the same as for
+   :func:`urlopen`.
+
+   The second argument, if present, specifies the file location to copy to (if
+   absent, the location will be a tempfile with a generated name). The third
+   argument, if present, is a hook function that will be called once on
+   establishment of the network connection and once after each block read
+   thereafter.  The hook will be passed three arguments; a count of blocks
+   transferred so far, a block size in bytes, and the total size of the file.  The
+   third argument may be ``-1`` on older FTP servers which do not return a file
+   size in response to a retrieval request.
+
+   If the *url* uses the :file:`http:` scheme identifier, the optional *data*
+   argument may be given to specify a ``POST`` request (normally the request type
+   is ``GET``).  The *data* argument must in standard
+   :mimetype:`application/x-www-form-urlencoded` format; see the :func:`urlencode`
+   function below.
+
+   .. versionchanged:: 2.5
+      :func:`urlretrieve` will raise :exc:`ContentTooShortError` when it detects that
+      the amount of data available  was less than the expected amount (which is the
+      size reported by a  *Content-Length* header). This can occur, for example, when
+      the  download is interrupted.
+
+      The *Content-Length* is treated as a lower bound: if there's more data  to read,
+      urlretrieve reads more data, but if less data is available,  it raises the
+      exception.
+
+      You can still retrieve the downloaded data in this case, it is stored  in the
+      :attr:`content` attribute of the exception instance.
+
+      If no *Content-Length* header was supplied, urlretrieve can not check the size
+      of the data it has downloaded, and just returns it.  In this case you just have
+      to assume that the download was successful.
+
+
+.. data:: _urlopener
+
+   The public functions :func:`urlopen` and :func:`urlretrieve` create an instance
+   of the :class:`FancyURLopener` class and use it to perform their requested
+   actions.  To override this functionality, programmers can create a subclass of
+   :class:`URLopener` or :class:`FancyURLopener`, then assign an instance of that
+   class to the ``urllib._urlopener`` variable before calling the desired function.
+   For example, applications may want to specify a different
+   :mailheader:`User-Agent` header than :class:`URLopener` defines.  This can be
+   accomplished with the following code::
+
+      import urllib
+
+      class AppURLopener(urllib.FancyURLopener):
+          version = "App/1.7"
+
+      urllib._urlopener = AppURLopener()
+
+
+.. function:: urlcleanup()
+
+   Clear the cache that may have been built up by previous calls to
+   :func:`urlretrieve`.
+
+
+.. function:: quote(string[, safe])
+
+   Replace special characters in *string* using the ``%xx`` escape. Letters,
+   digits, and the characters ``'_.-'`` are never quoted. The optional *safe*
+   parameter specifies additional characters that should not be quoted --- its
+   default value is ``'/'``.
+
+   Example: ``quote('/~connolly/')`` yields ``'/%7econnolly/'``.
+
+
+.. function:: quote_plus(string[, safe])
+
+   Like :func:`quote`, but also replaces spaces by plus signs, as required for
+   quoting HTML form values.  Plus signs in the original string are escaped unless
+   they are included in *safe*.  It also does not have *safe* default to ``'/'``.
+
+
+.. function:: unquote(string)
+
+   Replace ``%xx`` escapes by their single-character equivalent.
+
+   Example: ``unquote('/%7Econnolly/')`` yields ``'/~connolly/'``.
+
+
+.. function:: unquote_plus(string)
+
+   Like :func:`unquote`, but also replaces plus signs by spaces, as required for
+   unquoting HTML form values.
+
+
+.. function:: urlencode(query[, doseq])
+
+   Convert a mapping object or a sequence of two-element tuples  to a "url-encoded"
+   string, suitable to pass to :func:`urlopen` above as the optional *data*
+   argument.  This is useful to pass a dictionary of form fields to a ``POST``
+   request.  The resulting string is a series of ``key=value`` pairs separated by
+   ``'&'`` characters, where both *key* and *value* are quoted using
+   :func:`quote_plus` above.  If the optional parameter *doseq* is present and
+   evaluates to true, individual ``key=value`` pairs are generated for each element
+   of the sequence. When a sequence of two-element tuples is used as the *query*
+   argument, the first element of each tuple is a key and the second is a value.
+   The order of parameters in the encoded string will match the order of parameter
+   tuples in the sequence. The :mod:`cgi` module provides the functions
+   :func:`parse_qs` and :func:`parse_qsl` which are used to parse query strings
+   into Python data structures.
+
+
+.. function:: pathname2url(path)
+
+   Convert the pathname *path* from the local syntax for a path to the form used in
+   the path component of a URL.  This does not produce a complete URL.  The return
+   value will already be quoted using the :func:`quote` function.
+
+
+.. function:: url2pathname(path)
+
+   Convert the path component *path* from an encoded URL to the local syntax for a
+   path.  This does not accept a complete URL.  This function uses :func:`unquote`
+   to decode *path*.
+
+
+.. class:: URLopener([proxies[, **x509]])
+
+   Base class for opening and reading URLs.  Unless you need to support opening
+   objects using schemes other than :file:`http:`, :file:`ftp:`, or :file:`file:`,
+   you probably want to use :class:`FancyURLopener`.
+
+   By default, the :class:`URLopener` class sends a :mailheader:`User-Agent` header
+   of ``urllib/VVV``, where *VVV* is the :mod:`urllib` version number.
+   Applications can define their own :mailheader:`User-Agent` header by subclassing
+   :class:`URLopener` or :class:`FancyURLopener` and setting the class attribute
+   :attr:`version` to an appropriate string value in the subclass definition.
+
+   The optional *proxies* parameter should be a dictionary mapping scheme names to
+   proxy URLs, where an empty dictionary turns proxies off completely.  Its default
+   value is ``None``, in which case environmental proxy settings will be used if
+   present, as discussed in the definition of :func:`urlopen`, above.
+
+   Additional keyword parameters, collected in *x509*, may be used for
+   authentication of the client when using the :file:`https:` scheme.  The keywords
+   *key_file* and *cert_file* are supported to provide an  SSL key and certificate;
+   both are needed to support client authentication.
+
+   :class:`URLopener` objects will raise an :exc:`IOError` exception if the server
+   returns an error code.
+
+
+.. class:: FancyURLopener(...)
+
+   :class:`FancyURLopener` subclasses :class:`URLopener` providing default handling
+   for the following HTTP response codes: 301, 302, 303, 307 and 401.  For the 30x
+   response codes listed above, the :mailheader:`Location` header is used to fetch
+   the actual URL.  For 401 response codes (authentication required), basic HTTP
+   authentication is performed.  For the 30x response codes, recursion is bounded
+   by the value of the *maxtries* attribute, which defaults to 10.
+
+   For all other response codes, the method :meth:`http_error_default` is called
+   which you can override in subclasses to handle the error appropriately.
+
+   .. note::
+
+      According to the letter of :rfc:`2616`, 301 and 302 responses to POST requests
+      must not be automatically redirected without confirmation by the user.  In
+      reality, browsers do allow automatic redirection of these responses, changing
+      the POST to a GET, and :mod:`urllib` reproduces this behaviour.
+
+   The parameters to the constructor are the same as those for :class:`URLopener`.
+
+   .. note::
+
+      When performing basic authentication, a :class:`FancyURLopener` instance calls
+      its :meth:`prompt_user_passwd` method.  The default implementation asks the
+      users for the required information on the controlling terminal.  A subclass may
+      override this method to support more appropriate behavior if needed.
+
+
+.. exception:: ContentTooShortError(msg[, content])
+
+   This exception is raised when the :func:`urlretrieve` function detects that the
+   amount of the downloaded data is less than the  expected amount (given by the
+   *Content-Length* header). The :attr:`content` attribute stores the downloaded
+   (and supposedly truncated) data.
+
+   .. versionadded:: 2.5
+
+Restrictions:
+
+  .. index::
+     pair: HTTP; protocol
+     pair: FTP; protocol
+
+* Currently, only the following protocols are supported: HTTP, (versions 0.9 and
+  1.0),  FTP, and local files.
+
+* The caching feature of :func:`urlretrieve` has been disabled until I find the
+  time to hack proper processing of Expiration time headers.
+
+* There should be a function to query whether a particular URL is in the cache.
+
+* For backward compatibility, if a URL appears to point to a local file but the
+  file can't be opened, the URL is re-interpreted using the FTP protocol.  This
+  can sometimes cause confusing error messages.
+
+* The :func:`urlopen` and :func:`urlretrieve` functions can cause arbitrarily
+  long delays while waiting for a network connection to be set up.  This means
+  that it is difficult to build an interactive Web client using these functions
+  without using threads.
+
+  .. index::
+     single: HTML
+     pair: HTTP; protocol
+     module: htmllib
+
+* The data returned by :func:`urlopen` or :func:`urlretrieve` is the raw data
+  returned by the server.  This may be binary data (such as an image), plain text
+  or (for example) HTML.  The HTTP protocol provides type information in the reply
+  header, which can be inspected by looking at the :mailheader:`Content-Type`
+  header.  If the returned data is HTML, you can use the module :mod:`htmllib` to
+  parse it.
+
+  .. index:: single: FTP
+
+* The code handling the FTP protocol cannot differentiate between a file and a
+  directory.  This can lead to unexpected behavior when attempting to read a URL
+  that points to a file that is not accessible.  If the URL ends in a ``/``, it is
+  assumed to refer to a directory and will be handled accordingly.  But if an
+  attempt to read a file leads to a 550 error (meaning the URL cannot be found or
+  is not accessible, often for permission reasons), then the path is treated as a
+  directory in order to handle the case when a directory is specified by a URL but
+  the trailing ``/`` has been left off.  This can cause misleading results when
+  you try to fetch a file whose read permissions make it inaccessible; the FTP
+  code will try to read it, fail with a 550 error, and then perform a directory
+  listing for the unreadable file. If fine-grained control is needed, consider
+  using the :mod:`ftplib` module, subclassing :class:`FancyURLOpener`, or changing
+  *_urlopener* to meet your needs.
+
+* This module does not support the use of proxies which require authentication.
+  This may be implemented in the future.
+
+  .. index:: module: urlparse
+
+* Although the :mod:`urllib` module contains (undocumented) routines to parse
+  and unparse URL strings, the recommended interface for URL manipulation is in
+  module :mod:`urlparse`.
+
+
+.. _urlopener-objs:
+
+URLopener Objects
+-----------------
+
+.. sectionauthor:: Skip Montanaro <skip@mojam.com>
+
+
+:class:`URLopener` and :class:`FancyURLopener` objects have the following
+attributes.
+
+
+.. method:: URLopener.open(fullurl[, data])
+
+   Open *fullurl* using the appropriate protocol.  This method sets up cache and
+   proxy information, then calls the appropriate open method with its input
+   arguments.  If the scheme is not recognized, :meth:`open_unknown` is called.
+   The *data* argument has the same meaning as the *data* argument of
+   :func:`urlopen`.
+
+
+.. method:: URLopener.open_unknown(fullurl[, data])
+
+   Overridable interface to open unknown URL types.
+
+
+.. method:: URLopener.retrieve(url[, filename[, reporthook[, data]]])
+
+   Retrieves the contents of *url* and places it in *filename*.  The return value
+   is a tuple consisting of a local filename and either a
+   :class:`mimetools.Message` object containing the response headers (for remote
+   URLs) or ``None`` (for local URLs).  The caller must then open and read the
+   contents of *filename*.  If *filename* is not given and the URL refers to a
+   local file, the input filename is returned.  If the URL is non-local and
+   *filename* is not given, the filename is the output of :func:`tempfile.mktemp`
+   with a suffix that matches the suffix of the last path component of the input
+   URL.  If *reporthook* is given, it must be a function accepting three numeric
+   parameters.  It will be called after each chunk of data is read from the
+   network.  *reporthook* is ignored for local URLs.
+
+   If the *url* uses the :file:`http:` scheme identifier, the optional *data*
+   argument may be given to specify a ``POST`` request (normally the request type
+   is ``GET``).  The *data* argument must in standard
+   :mimetype:`application/x-www-form-urlencoded` format; see the :func:`urlencode`
+   function below.
+
+
+.. attribute:: URLopener.version
+
+   Variable that specifies the user agent of the opener object.  To get
+   :mod:`urllib` to tell servers that it is a particular user agent, set this in a
+   subclass as a class variable or in the constructor before calling the base
+   constructor.
+
+The :class:`FancyURLopener` class offers one additional method that should be
+overloaded to provide the appropriate behavior:
+
+
+.. method:: FancyURLopener.prompt_user_passwd(host, realm)
+
+   Return information needed to authenticate the user at the given host in the
+   specified security realm.  The return value should be a tuple, ``(user,
+   password)``, which can be used for basic authentication.
+
+   The implementation prompts for this information on the terminal; an application
+   should override this method to use an appropriate interaction model in the local
+   environment.
+
+
+.. _urllib-examples:
+
+Examples
+--------
+
+Here is an example session that uses the ``GET`` method to retrieve a URL
+containing parameters::
+
+   >>> import urllib
+   >>> params = urllib.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
+   >>> f = urllib.urlopen("http://www.musi-cal.com/cgi-bin/query?%s" % params)
+   >>> print f.read()
+
+The following example uses the ``POST`` method instead::
+
+   >>> import urllib
+   >>> params = urllib.urlencode({'spam': 1, 'eggs': 2, 'bacon': 0})
+   >>> f = urllib.urlopen("http://www.musi-cal.com/cgi-bin/query", params)
+   >>> print f.read()
+
+The following example uses an explicitly specified HTTP proxy, overriding
+environment settings::
+
+   >>> import urllib
+   >>> proxies = {'http': 'http://proxy.example.com:8080/'}
+   >>> opener = urllib.FancyURLopener(proxies)
+   >>> f = opener.open("http://www.python.org")
+   >>> f.read()
+
+The following example uses no proxies at all, overriding environment settings::
+
+   >>> import urllib
+   >>> opener = urllib.FancyURLopener({})
+   >>> f = opener.open("http://www.python.org/")
+   >>> f.read()
+
diff --git a/Doc/library/urllib2.rst b/Doc/library/urllib2.rst
new file mode 100644
index 0000000..41bb033
--- /dev/null
+++ b/Doc/library/urllib2.rst
@@ -0,0 +1,927 @@
+:mod:`urllib2` --- extensible library for opening URLs
+======================================================
+
+.. module:: urllib2
+   :synopsis: Next generation URL opening library.
+.. moduleauthor:: Jeremy Hylton <jhylton@users.sourceforge.net>
+.. sectionauthor:: Moshe Zadka <moshez@users.sourceforge.net>
+
+
+The :mod:`urllib2` module defines functions and classes which help in opening
+URLs (mostly HTTP) in a complex world --- basic and digest authentication,
+redirections, cookies and more.
+
+The :mod:`urllib2` module defines the following functions:
+
+
+.. function:: urlopen(url[, data][, timeout])
+
+   Open the URL *url*, which can be either a string or a :class:`Request` object.
+
+   *data* may be a string specifying additional data to send to the server, or
+   ``None`` if no such data is needed.  Currently HTTP requests are the only ones
+   that use *data*; the HTTP request will be a POST instead of a GET when the
+   *data* parameter is provided.  *data* should be a buffer in the standard
+   :mimetype:`application/x-www-form-urlencoded` format.  The
+   :func:`urllib.urlencode` function takes a mapping or sequence of 2-tuples and
+   returns a string in this format.
+
+   The optional *timeout* parameter specifies a timeout in seconds for the
+   connection attempt (if not specified, or passed as None, the global default
+   timeout setting will be used). This actually only work for HTTP, HTTPS, FTP and
+   FTPS connections.
+
+   This function returns a file-like object with two additional methods:
+
+   * :meth:`geturl` --- return the URL of the resource retrieved
+
+   * :meth:`info` --- return the meta-information of the page, as a dictionary-like
+     object
+
+   Raises :exc:`URLError` on errors.
+
+   Note that ``None`` may be returned if no handler handles the request (though the
+   default installed global :class:`OpenerDirector` uses :class:`UnknownHandler` to
+   ensure this never happens).
+
+   .. versionchanged:: 2.6
+      *timeout* was added.
+
+
+.. function:: install_opener(opener)
+
+   Install an :class:`OpenerDirector` instance as the default global opener.
+   Installing an opener is only necessary if you want urlopen to use that opener;
+   otherwise, simply call :meth:`OpenerDirector.open` instead of :func:`urlopen`.
+   The code does not check for a real :class:`OpenerDirector`, and any class with
+   the appropriate interface will work.
+
+
+.. function:: build_opener([handler, ...])
+
+   Return an :class:`OpenerDirector` instance, which chains the handlers in the
+   order given. *handler*\s can be either instances of :class:`BaseHandler`, or
+   subclasses of :class:`BaseHandler` (in which case it must be possible to call
+   the constructor without any parameters).  Instances of the following classes
+   will be in front of the *handler*\s, unless the *handler*\s contain them,
+   instances of them or subclasses of them: :class:`ProxyHandler`,
+   :class:`UnknownHandler`, :class:`HTTPHandler`, :class:`HTTPDefaultErrorHandler`,
+   :class:`HTTPRedirectHandler`, :class:`FTPHandler`, :class:`FileHandler`,
+   :class:`HTTPErrorProcessor`.
+
+   If the Python installation has SSL support (:func:`socket.ssl` exists),
+   :class:`HTTPSHandler` will also be added.
+
+   Beginning in Python 2.3, a :class:`BaseHandler` subclass may also change its
+   :attr:`handler_order` member variable to modify its position in the handlers
+   list.
+
+The following exceptions are raised as appropriate:
+
+
+.. exception:: URLError
+
+   The handlers raise this exception (or derived exceptions) when they run into a
+   problem.  It is a subclass of :exc:`IOError`.
+
+
+.. exception:: HTTPError
+
+   A subclass of :exc:`URLError`, it can also function as a non-exceptional
+   file-like return value (the same thing that :func:`urlopen` returns).  This
+   is useful when handling exotic HTTP errors, such as requests for
+   authentication.
+
+The following classes are provided:
+
+
+.. class:: Request(url[, data][, headers] [, origin_req_host][, unverifiable])
+
+   This class is an abstraction of a URL request.
+
+   *url* should be a string containing a valid URL.
+
+   *data* may be a string specifying additional data to send to the server, or
+   ``None`` if no such data is needed.  Currently HTTP requests are the only ones
+   that use *data*; the HTTP request will be a POST instead of a GET when the
+   *data* parameter is provided.  *data* should be a buffer in the standard
+   :mimetype:`application/x-www-form-urlencoded` format.  The
+   :func:`urllib.urlencode` function takes a mapping or sequence of 2-tuples and
+   returns a string in this format.
+
+   *headers* should be a dictionary, and will be treated as if :meth:`add_header`
+   was called with each key and value as arguments.
+
+   The final two arguments are only of interest for correct handling of third-party
+   HTTP cookies:
+
+   *origin_req_host* should be the request-host of the origin transaction, as
+   defined by :rfc:`2965`.  It defaults to ``cookielib.request_host(self)``.  This
+   is the host name or IP address of the original request that was initiated by the
+   user.  For example, if the request is for an image in an HTML document, this
+   should be the request-host of the request for the page containing the image.
+
+   *unverifiable* should indicate whether the request is unverifiable, as defined
+   by RFC 2965.  It defaults to False.  An unverifiable request is one whose URL
+   the user did not have the option to approve.  For example, if the request is for
+   an image in an HTML document, and the user had no option to approve the
+   automatic fetching of the image, this should be true.
+
+
+.. class:: OpenerDirector()
+
+   The :class:`OpenerDirector` class opens URLs via :class:`BaseHandler`\ s chained
+   together. It manages the chaining of handlers, and recovery from errors.
+
+
+.. class:: BaseHandler()
+
+   This is the base class for all registered handlers --- and handles only the
+   simple mechanics of registration.
+
+
+.. class:: HTTPDefaultErrorHandler()
+
+   A class which defines a default handler for HTTP error responses; all responses
+   are turned into :exc:`HTTPError` exceptions.
+
+
+.. class:: HTTPRedirectHandler()
+
+   A class to handle redirections.
+
+
+.. class:: HTTPCookieProcessor([cookiejar])
+
+   A class to handle HTTP Cookies.
+
+
+.. class:: ProxyHandler([proxies])
+
+   Cause requests to go through a proxy. If *proxies* is given, it must be a
+   dictionary mapping protocol names to URLs of proxies. The default is to read the
+   list of proxies from the environment variables :envvar:`<protocol>_proxy`.
+
+
+.. class:: HTTPPasswordMgr()
+
+   Keep a database of  ``(realm, uri) -> (user, password)`` mappings.
+
+
+.. class:: HTTPPasswordMgrWithDefaultRealm()
+
+   Keep a database of  ``(realm, uri) -> (user, password)`` mappings. A realm of
+   ``None`` is considered a catch-all realm, which is searched if no other realm
+   fits.
+
+
+.. class:: AbstractBasicAuthHandler([password_mgr])
+
+   This is a mixin class that helps with HTTP authentication, both to the remote
+   host and to a proxy. *password_mgr*, if given, should be something that is
+   compatible with :class:`HTTPPasswordMgr`; refer to section
+   :ref:`http-password-mgr` for information on the interface that must be
+   supported.
+
+
+.. class:: HTTPBasicAuthHandler([password_mgr])
+
+   Handle authentication with the remote host. *password_mgr*, if given, should be
+   something that is compatible with :class:`HTTPPasswordMgr`; refer to section
+   :ref:`http-password-mgr` for information on the interface that must be
+   supported.
+
+
+.. class:: ProxyBasicAuthHandler([password_mgr])
+
+   Handle authentication with the proxy. *password_mgr*, if given, should be
+   something that is compatible with :class:`HTTPPasswordMgr`; refer to section
+   :ref:`http-password-mgr` for information on the interface that must be
+   supported.
+
+
+.. class:: AbstractDigestAuthHandler([password_mgr])
+
+   This is a mixin class that helps with HTTP authentication, both to the remote
+   host and to a proxy. *password_mgr*, if given, should be something that is
+   compatible with :class:`HTTPPasswordMgr`; refer to section
+   :ref:`http-password-mgr` for information on the interface that must be
+   supported.
+
+
+.. class:: HTTPDigestAuthHandler([password_mgr])
+
+   Handle authentication with the remote host. *password_mgr*, if given, should be
+   something that is compatible with :class:`HTTPPasswordMgr`; refer to section
+   :ref:`http-password-mgr` for information on the interface that must be
+   supported.
+
+
+.. class:: ProxyDigestAuthHandler([password_mgr])
+
+   Handle authentication with the proxy. *password_mgr*, if given, should be
+   something that is compatible with :class:`HTTPPasswordMgr`; refer to section
+   :ref:`http-password-mgr` for information on the interface that must be
+   supported.
+
+
+.. class:: HTTPHandler()
+
+   A class to handle opening of HTTP URLs.
+
+
+.. class:: HTTPSHandler()
+
+   A class to handle opening of HTTPS URLs.
+
+
+.. class:: FileHandler()
+
+   Open local files.
+
+
+.. class:: FTPHandler()
+
+   Open FTP URLs.
+
+
+.. class:: CacheFTPHandler()
+
+   Open FTP URLs, keeping a cache of open FTP connections to minimize delays.
+
+
+.. class:: UnknownHandler()
+
+   A catch-all class to handle unknown URLs.
+
+
+.. _request-objects:
+
+Request Objects
+---------------
+
+The following methods describe all of :class:`Request`'s public interface, and
+so all must be overridden in subclasses.
+
+
+.. method:: Request.add_data(data)
+
+   Set the :class:`Request` data to *data*.  This is ignored by all handlers except
+   HTTP handlers --- and there it should be a byte string, and will change the
+   request to be ``POST`` rather than ``GET``.
+
+
+.. method:: Request.get_method()
+
+   Return a string indicating the HTTP request method.  This is only meaningful for
+   HTTP requests, and currently always returns ``'GET'`` or ``'POST'``.
+
+
+.. method:: Request.has_data()
+
+   Return whether the instance has a non-\ ``None`` data.
+
+
+.. method:: Request.get_data()
+
+   Return the instance's data.
+
+
+.. method:: Request.add_header(key, val)
+
+   Add another header to the request.  Headers are currently ignored by all
+   handlers except HTTP handlers, where they are added to the list of headers sent
+   to the server.  Note that there cannot be more than one header with the same
+   name, and later calls will overwrite previous calls in case the *key* collides.
+   Currently, this is no loss of HTTP functionality, since all headers which have
+   meaning when used more than once have a (header-specific) way of gaining the
+   same functionality using only one header.
+
+
+.. method:: Request.add_unredirected_header(key, header)
+
+   Add a header that will not be added to a redirected request.
+
+   .. versionadded:: 2.4
+
+
+.. method:: Request.has_header(header)
+
+   Return whether the instance has the named header (checks both regular and
+   unredirected).
+
+   .. versionadded:: 2.4
+
+
+.. method:: Request.get_full_url()
+
+   Return the URL given in the constructor.
+
+
+.. method:: Request.get_type()
+
+   Return the type of the URL --- also known as the scheme.
+
+
+.. method:: Request.get_host()
+
+   Return the host to which a connection will be made.
+
+
+.. method:: Request.get_selector()
+
+   Return the selector --- the part of the URL that is sent to the server.
+
+
+.. method:: Request.set_proxy(host, type)
+
+   Prepare the request by connecting to a proxy server. The *host* and *type* will
+   replace those of the instance, and the instance's selector will be the original
+   URL given in the constructor.
+
+
+.. method:: Request.get_origin_req_host()
+
+   Return the request-host of the origin transaction, as defined by :rfc:`2965`.
+   See the documentation for the :class:`Request` constructor.
+
+
+.. method:: Request.is_unverifiable()
+
+   Return whether the request is unverifiable, as defined by RFC 2965. See the
+   documentation for the :class:`Request` constructor.
+
+
+.. _opener-director-objects:
+
+OpenerDirector Objects
+----------------------
+
+:class:`OpenerDirector` instances have the following methods:
+
+
+.. method:: OpenerDirector.add_handler(handler)
+
+   *handler* should be an instance of :class:`BaseHandler`.  The following methods
+   are searched, and added to the possible chains (note that HTTP errors are a
+   special case).
+
+   * :meth:`protocol_open` --- signal that the handler knows how to open *protocol*
+     URLs.
+
+   * :meth:`http_error_type` --- signal that the handler knows how to handle HTTP
+     errors with HTTP error code *type*.
+
+   * :meth:`protocol_error` --- signal that the handler knows how to handle errors
+     from (non-\ ``http``) *protocol*.
+
+   * :meth:`protocol_request` --- signal that the handler knows how to pre-process
+     *protocol* requests.
+
+   * :meth:`protocol_response` --- signal that the handler knows how to
+     post-process *protocol* responses.
+
+
+.. method:: OpenerDirector.open(url[, data][, timeout])
+
+   Open the given *url* (which can be a request object or a string), optionally
+   passing the given *data*. Arguments, return values and exceptions raised are the
+   same as those of :func:`urlopen` (which simply calls the :meth:`open` method on
+   the currently installed global :class:`OpenerDirector`).  The optional *timeout*
+   parameter specifies a timeout in seconds for the connection  attempt (if not
+   specified, or passed as None, the global default timeout  setting will be used;
+   this actually only work for HTTP, HTTPS, FTP and FTPS connections).
+
+   .. versionchanged:: 2.6
+      *timeout* was added.
+
+
+.. method:: OpenerDirector.error(proto[, arg[, ...]])
+
+   Handle an error of the given protocol.  This will call the registered error
+   handlers for the given protocol with the given arguments (which are protocol
+   specific).  The HTTP protocol is a special case which uses the HTTP response
+   code to determine the specific error handler; refer to the :meth:`http_error_\*`
+   methods of the handler classes.
+
+   Return values and exceptions raised are the same as those of :func:`urlopen`.
+
+OpenerDirector objects open URLs in three stages:
+
+The order in which these methods are called within each stage is determined by
+sorting the handler instances.
+
+#. Every handler with a method named like :meth:`protocol_request` has that
+   method called to pre-process the request.
+
+#. Handlers with a method named like :meth:`protocol_open` are called to handle
+   the request. This stage ends when a handler either returns a non-\ :const:`None`
+   value (ie. a response), or raises an exception (usually :exc:`URLError`).
+   Exceptions are allowed to propagate.
+
+   In fact, the above algorithm is first tried for methods named
+   :meth:`default_open`.  If all such methods return :const:`None`, the algorithm
+   is repeated for methods named like :meth:`protocol_open`.  If all such methods
+   return :const:`None`, the algorithm is repeated for methods named
+   :meth:`unknown_open`.
+
+   Note that the implementation of these methods may involve calls of the parent
+   :class:`OpenerDirector` instance's :meth:`.open` and :meth:`.error` methods.
+
+#. Every handler with a method named like :meth:`protocol_response` has that
+   method called to post-process the response.
+
+
+.. _base-handler-objects:
+
+BaseHandler Objects
+-------------------
+
+:class:`BaseHandler` objects provide a couple of methods that are directly
+useful, and others that are meant to be used by derived classes.  These are
+intended for direct use:
+
+
+.. method:: BaseHandler.add_parent(director)
+
+   Add a director as parent.
+
+
+.. method:: BaseHandler.close()
+
+   Remove any parents.
+
+The following members and methods should only be used by classes derived from
+:class:`BaseHandler`.
+
+.. note::
+
+   The convention has been adopted that subclasses defining
+   :meth:`protocol_request` or :meth:`protocol_response` methods are named
+   :class:`\*Processor`; all others are named :class:`\*Handler`.
+
+
+.. attribute:: BaseHandler.parent
+
+   A valid :class:`OpenerDirector`, which can be used to open using a different
+   protocol, or handle errors.
+
+
+.. method:: BaseHandler.default_open(req)
+
+   This method is *not* defined in :class:`BaseHandler`, but subclasses should
+   define it if they want to catch all URLs.
+
+   This method, if implemented, will be called by the parent
+   :class:`OpenerDirector`.  It should return a file-like object as described in
+   the return value of the :meth:`open` of :class:`OpenerDirector`, or ``None``.
+   It should raise :exc:`URLError`, unless a truly exceptional thing happens (for
+   example, :exc:`MemoryError` should not be mapped to :exc:`URLError`).
+
+   This method will be called before any protocol-specific open method.
+
+
+.. method:: BaseHandler.protocol_open(req)
+   :noindex:
+
+   This method is *not* defined in :class:`BaseHandler`, but subclasses should
+   define it if they want to handle URLs with the given protocol.
+
+   This method, if defined, will be called by the parent :class:`OpenerDirector`.
+   Return values should be the same as for  :meth:`default_open`.
+
+
+.. method:: BaseHandler.unknown_open(req)
+
+   This method is *not* defined in :class:`BaseHandler`, but subclasses should
+   define it if they want to catch all URLs with no specific registered handler to
+   open it.
+
+   This method, if implemented, will be called by the :attr:`parent`
+   :class:`OpenerDirector`.  Return values should be the same as for
+   :meth:`default_open`.
+
+
+.. method:: BaseHandler.http_error_default(req, fp, code, msg, hdrs)
+
+   This method is *not* defined in :class:`BaseHandler`, but subclasses should
+   override it if they intend to provide a catch-all for otherwise unhandled HTTP
+   errors.  It will be called automatically by the  :class:`OpenerDirector` getting
+   the error, and should not normally be called in other circumstances.
+
+   *req* will be a :class:`Request` object, *fp* will be a file-like object with
+   the HTTP error body, *code* will be the three-digit code of the error, *msg*
+   will be the user-visible explanation of the code and *hdrs* will be a mapping
+   object with the headers of the error.
+
+   Return values and exceptions raised should be the same as those of
+   :func:`urlopen`.
+
+
+.. method:: BaseHandler.http_error_nnn(req, fp, code, msg, hdrs)
+
+   *nnn* should be a three-digit HTTP error code.  This method is also not defined
+   in :class:`BaseHandler`, but will be called, if it exists, on an instance of a
+   subclass, when an HTTP error with code *nnn* occurs.
+
+   Subclasses should override this method to handle specific HTTP errors.
+
+   Arguments, return values and exceptions raised should be the same as for
+   :meth:`http_error_default`.
+
+
+.. method:: BaseHandler.protocol_request(req)
+   :noindex:
+
+   This method is *not* defined in :class:`BaseHandler`, but subclasses should
+   define it if they want to pre-process requests of the given protocol.
+
+   This method, if defined, will be called by the parent :class:`OpenerDirector`.
+   *req* will be a :class:`Request` object. The return value should be a
+   :class:`Request` object.
+
+
+.. method:: BaseHandler.protocol_response(req, response)
+   :noindex:
+
+   This method is *not* defined in :class:`BaseHandler`, but subclasses should
+   define it if they want to post-process responses of the given protocol.
+
+   This method, if defined, will be called by the parent :class:`OpenerDirector`.
+   *req* will be a :class:`Request` object. *response* will be an object
+   implementing the same interface as the return value of :func:`urlopen`.  The
+   return value should implement the same interface as the return value of
+   :func:`urlopen`.
+
+
+.. _http-redirect-handler:
+
+HTTPRedirectHandler Objects
+---------------------------
+
+.. note::
+
+   Some HTTP redirections require action from this module's client code.  If this
+   is the case, :exc:`HTTPError` is raised.  See :rfc:`2616` for details of the
+   precise meanings of the various redirection codes.
+
+
+.. method:: HTTPRedirectHandler.redirect_request(req, fp, code, msg, hdrs)
+
+   Return a :class:`Request` or ``None`` in response to a redirect. This is called
+   by the default implementations of the :meth:`http_error_30\*` methods when a
+   redirection is received from the server.  If a redirection should take place,
+   return a new :class:`Request` to allow :meth:`http_error_30\*` to perform the
+   redirect.  Otherwise, raise :exc:`HTTPError` if no other handler should try to
+   handle this URL, or return ``None`` if you can't but another handler might.
+
+   .. note::
+
+      The default implementation of this method does not strictly follow :rfc:`2616`,
+      which says that 301 and 302 responses to ``POST`` requests must not be
+      automatically redirected without confirmation by the user.  In reality, browsers
+      do allow automatic redirection of these responses, changing the POST to a
+      ``GET``, and the default implementation reproduces this behavior.
+
+
+.. method:: HTTPRedirectHandler.http_error_301(req, fp, code, msg, hdrs)
+
+   Redirect to the ``Location:`` URL.  This method is called by the parent
+   :class:`OpenerDirector` when getting an HTTP 'moved permanently' response.
+
+
+.. method:: HTTPRedirectHandler.http_error_302(req, fp, code, msg, hdrs)
+
+   The same as :meth:`http_error_301`, but called for the 'found' response.
+
+
+.. method:: HTTPRedirectHandler.http_error_303(req, fp, code, msg, hdrs)
+
+   The same as :meth:`http_error_301`, but called for the 'see other' response.
+
+
+.. method:: HTTPRedirectHandler.http_error_307(req, fp, code, msg, hdrs)
+
+   The same as :meth:`http_error_301`, but called for the 'temporary redirect'
+   response.
+
+
+.. _http-cookie-processor:
+
+HTTPCookieProcessor Objects
+---------------------------
+
+.. versionadded:: 2.4
+
+:class:`HTTPCookieProcessor` instances have one attribute:
+
+
+.. attribute:: HTTPCookieProcessor.cookiejar
+
+   The :class:`cookielib.CookieJar` in which cookies are stored.
+
+
+.. _proxy-handler:
+
+ProxyHandler Objects
+--------------------
+
+
+.. method:: ProxyHandler.protocol_open(request)
+   :noindex:
+
+   The :class:`ProxyHandler` will have a method :meth:`protocol_open` for every
+   *protocol* which has a proxy in the *proxies* dictionary given in the
+   constructor.  The method will modify requests to go through the proxy, by
+   calling ``request.set_proxy()``, and call the next handler in the chain to
+   actually execute the protocol.
+
+
+.. _http-password-mgr:
+
+HTTPPasswordMgr Objects
+-----------------------
+
+These methods are available on :class:`HTTPPasswordMgr` and
+:class:`HTTPPasswordMgrWithDefaultRealm` objects.
+
+
+.. method:: HTTPPasswordMgr.add_password(realm, uri, user, passwd)
+
+   *uri* can be either a single URI, or a sequence of URIs. *realm*, *user* and
+   *passwd* must be strings. This causes ``(user, passwd)`` to be used as
+   authentication tokens when authentication for *realm* and a super-URI of any of
+   the given URIs is given.
+
+
+.. method:: HTTPPasswordMgr.find_user_password(realm, authuri)
+
+   Get user/password for given realm and URI, if any.  This method will return
+   ``(None, None)`` if there is no matching user/password.
+
+   For :class:`HTTPPasswordMgrWithDefaultRealm` objects, the realm ``None`` will be
+   searched if the given *realm* has no matching user/password.
+
+
+.. _abstract-basic-auth-handler:
+
+AbstractBasicAuthHandler Objects
+--------------------------------
+
+
+.. method:: AbstractBasicAuthHandler.http_error_auth_reqed(authreq, host, req, headers)
+
+   Handle an authentication request by getting a user/password pair, and re-trying
+   the request.  *authreq* should be the name of the header where the information
+   about the realm is included in the request, *host* specifies the URL and path to
+   authenticate for, *req* should be the (failed) :class:`Request` object, and
+   *headers* should be the error headers.
+
+   *host* is either an authority (e.g. ``"python.org"``) or a URL containing an
+   authority component (e.g. ``"http://python.org/"``). In either case, the
+   authority must not contain a userinfo component (so, ``"python.org"`` and
+   ``"python.org:80"`` are fine, ``"joe:password@python.org"`` is not).
+
+
+.. _http-basic-auth-handler:
+
+HTTPBasicAuthHandler Objects
+----------------------------
+
+
+.. method:: HTTPBasicAuthHandler.http_error_401(req, fp, code,  msg, hdrs)
+
+   Retry the request with authentication information, if available.
+
+
+.. _proxy-basic-auth-handler:
+
+ProxyBasicAuthHandler Objects
+-----------------------------
+
+
+.. method:: ProxyBasicAuthHandler.http_error_407(req, fp, code,  msg, hdrs)
+
+   Retry the request with authentication information, if available.
+
+
+.. _abstract-digest-auth-handler:
+
+AbstractDigestAuthHandler Objects
+---------------------------------
+
+
+.. method:: AbstractDigestAuthHandler.http_error_auth_reqed(authreq, host, req, headers)
+
+   *authreq* should be the name of the header where the information about the realm
+   is included in the request, *host* should be the host to authenticate to, *req*
+   should be the (failed) :class:`Request` object, and *headers* should be the
+   error headers.
+
+
+.. _http-digest-auth-handler:
+
+HTTPDigestAuthHandler Objects
+-----------------------------
+
+
+.. method:: HTTPDigestAuthHandler.http_error_401(req, fp, code,  msg, hdrs)
+
+   Retry the request with authentication information, if available.
+
+
+.. _proxy-digest-auth-handler:
+
+ProxyDigestAuthHandler Objects
+------------------------------
+
+
+.. method:: ProxyDigestAuthHandler.http_error_407(req, fp, code,  msg, hdrs)
+
+   Retry the request with authentication information, if available.
+
+
+.. _http-handler-objects:
+
+HTTPHandler Objects
+-------------------
+
+
+.. method:: HTTPHandler.http_open(req)
+
+   Send an HTTP request, which can be either GET or POST, depending on
+   ``req.has_data()``.
+
+
+.. _https-handler-objects:
+
+HTTPSHandler Objects
+--------------------
+
+
+.. method:: HTTPSHandler.https_open(req)
+
+   Send an HTTPS request, which can be either GET or POST, depending on
+   ``req.has_data()``.
+
+
+.. _file-handler-objects:
+
+FileHandler Objects
+-------------------
+
+
+.. method:: FileHandler.file_open(req)
+
+   Open the file locally, if there is no host name, or the host name is
+   ``'localhost'``. Change the protocol to ``ftp`` otherwise, and retry opening it
+   using :attr:`parent`.
+
+
+.. _ftp-handler-objects:
+
+FTPHandler Objects
+------------------
+
+
+.. method:: FTPHandler.ftp_open(req)
+
+   Open the FTP file indicated by *req*. The login is always done with empty
+   username and password.
+
+
+.. _cacheftp-handler-objects:
+
+CacheFTPHandler Objects
+-----------------------
+
+:class:`CacheFTPHandler` objects are :class:`FTPHandler` objects with the
+following additional methods:
+
+
+.. method:: CacheFTPHandler.setTimeout(t)
+
+   Set timeout of connections to *t* seconds.
+
+
+.. method:: CacheFTPHandler.setMaxConns(m)
+
+   Set maximum number of cached connections to *m*.
+
+
+.. _unknown-handler-objects:
+
+UnknownHandler Objects
+----------------------
+
+
+.. method:: UnknownHandler.unknown_open()
+
+   Raise a :exc:`URLError` exception.
+
+
+.. _http-error-processor-objects:
+
+HTTPErrorProcessor Objects
+--------------------------
+
+.. versionadded:: 2.4
+
+
+.. method:: HTTPErrorProcessor.unknown_open()
+
+   Process HTTP error responses.
+
+   For 200 error codes, the response object is returned immediately.
+
+   For non-200 error codes, this simply passes the job on to the
+   :meth:`protocol_error_code` handler methods, via :meth:`OpenerDirector.error`.
+   Eventually, :class:`urllib2.HTTPDefaultErrorHandler` will raise an
+   :exc:`HTTPError` if no other handler handles the error.
+
+
+.. _urllib2-examples:
+
+Examples
+--------
+
+This example gets the python.org main page and displays the first 100 bytes of
+it::
+
+   >>> import urllib2
+   >>> f = urllib2.urlopen('http://www.python.org/')
+   >>> print f.read(100)
+   <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+   <?xml-stylesheet href="./css/ht2html
+
+Here we are sending a data-stream to the stdin of a CGI and reading the data it
+returns to us. Note that this example will only work when the Python
+installation supports SSL. ::
+
+   >>> import urllib2
+   >>> req = urllib2.Request(url='https://localhost/cgi-bin/test.cgi',
+   ...                       data='This data is passed to stdin of the CGI')
+   >>> f = urllib2.urlopen(req)
+   >>> print f.read()
+   Got Data: "This data is passed to stdin of the CGI"
+
+The code for the sample CGI used in the above example is::
+
+   #!/usr/bin/env python
+   import sys
+   data = sys.stdin.read()
+   print 'Content-type: text-plain\n\nGot Data: "%s"' % data
+
+Use of Basic HTTP Authentication::
+
+   import urllib2
+   # Create an OpenerDirector with support for Basic HTTP Authentication...
+   auth_handler = urllib2.HTTPBasicAuthHandler()
+   auth_handler.add_password(realm='PDQ Application',
+                             uri='https://mahler:8092/site-updates.py',
+                             user='klem',
+                             passwd='kadidd!ehopper')
+   opener = urllib2.build_opener(auth_handler)
+   # ...and install it globally so it can be used with urlopen.
+   urllib2.install_opener(opener)
+   urllib2.urlopen('http://www.example.com/login.html')
+
+:func:`build_opener` provides many handlers by default, including a
+:class:`ProxyHandler`.  By default, :class:`ProxyHandler` uses the environment
+variables named ``<scheme>_proxy``, where ``<scheme>`` is the URL scheme
+involved.  For example, the :envvar:`http_proxy` environment variable is read to
+obtain the HTTP proxy's URL.
+
+This example replaces the default :class:`ProxyHandler` with one that uses
+programatically-supplied proxy URLs, and adds proxy authorization support with
+:class:`ProxyBasicAuthHandler`. ::
+
+   proxy_handler = urllib2.ProxyHandler({'http': 'http://www.example.com:3128/'})
+   proxy_auth_handler = urllib2.HTTPBasicAuthHandler()
+   proxy_auth_handler.add_password('realm', 'host', 'username', 'password')
+
+   opener = build_opener(proxy_handler, proxy_auth_handler)
+   # This time, rather than install the OpenerDirector, we use it directly:
+   opener.open('http://www.example.com/login.html')
+
+Adding HTTP headers:
+
+Use the *headers* argument to the :class:`Request` constructor, or::
+
+   import urllib2
+   req = urllib2.Request('http://www.example.com/')
+   req.add_header('Referer', 'http://www.python.org/')
+   r = urllib2.urlopen(req)
+
+:class:`OpenerDirector` automatically adds a :mailheader:`User-Agent` header to
+every :class:`Request`.  To change this::
+
+   import urllib2
+   opener = urllib2.build_opener()
+   opener.addheaders = [('User-agent', 'Mozilla/5.0')]
+   opener.open('http://www.example.com/')
+
+Also, remember that a few standard headers (:mailheader:`Content-Length`,
+:mailheader:`Content-Type` and :mailheader:`Host`) are added when the
+:class:`Request` is passed to :func:`urlopen` (or :meth:`OpenerDirector.open`).
+
diff --git a/Doc/library/urlparse.rst b/Doc/library/urlparse.rst
new file mode 100644
index 0000000..c6bc82b
--- /dev/null
+++ b/Doc/library/urlparse.rst
@@ -0,0 +1,268 @@
+:mod:`urlparse` --- Parse URLs into components
+==============================================
+
+.. module:: urlparse
+   :synopsis: Parse URLs into or assemble them from components.
+
+
+.. index::
+   single: WWW
+   single: World Wide Web
+   single: URL
+   pair: URL; parsing
+   pair: relative; URL
+
+This module defines a standard interface to break Uniform Resource Locator (URL)
+strings up in components (addressing scheme, network location, path etc.), to
+combine the components back into a URL string, and to convert a "relative URL"
+to an absolute URL given a "base URL."
+
+The module has been designed to match the Internet RFC on Relative Uniform
+Resource Locators (and discovered a bug in an earlier draft!). It supports the
+following URL schemes: ``file``, ``ftp``, ``gopher``, ``hdl``, ``http``,
+``https``, ``imap``, ``mailto``, ``mms``, ``news``,  ``nntp``, ``prospero``,
+``rsync``, ``rtsp``, ``rtspu``,  ``sftp``, ``shttp``, ``sip``, ``sips``,
+``snews``, ``svn``,  ``svn+ssh``, ``telnet``, ``wais``.
+
+.. versionadded:: 2.5
+   Support for the ``sftp`` and ``sips`` schemes.
+
+The :mod:`urlparse` module defines the following functions:
+
+
+.. function:: urlparse(urlstring[, default_scheme[, allow_fragments]])
+
+   Parse a URL into six components, returning a 6-tuple.  This corresponds to the
+   general structure of a URL: ``scheme://netloc/path;parameters?query#fragment``.
+   Each tuple item is a string, possibly empty. The components are not broken up in
+   smaller parts (for example, the network location is a single string), and %
+   escapes are not expanded. The delimiters as shown above are not part of the
+   result, except for a leading slash in the *path* component, which is retained if
+   present.  For example::
+
+      >>> from urlparse import urlparse
+      >>> o = urlparse('http://www.cwi.nl:80/%7Eguido/Python.html')
+      >>> o
+      ('http', 'www.cwi.nl:80', '/%7Eguido/Python.html', '', '', '')
+      >>> o.scheme
+      'http'
+      >>> o.port
+      80
+      >>> o.geturl()
+      'http://www.cwi.nl:80/%7Eguido/Python.html'
+
+   If the *default_scheme* argument is specified, it gives the default addressing
+   scheme, to be used only if the URL does not specify one.  The default value for
+   this argument is the empty string.
+
+   If the *allow_fragments* argument is false, fragment identifiers are not
+   allowed, even if the URL's addressing scheme normally does support them.  The
+   default value for this argument is :const:`True`.
+
+   The return value is actually an instance of a subclass of :class:`tuple`.  This
+   class has the following additional read-only convenience attributes:
+
+   +------------------+-------+--------------------------+----------------------+
+   | Attribute        | Index | Value                    | Value if not present |
+   +==================+=======+==========================+======================+
+   | :attr:`scheme`   | 0     | URL scheme specifier     | empty string         |
+   +------------------+-------+--------------------------+----------------------+
+   | :attr:`netloc`   | 1     | Network location part    | empty string         |
+   +------------------+-------+--------------------------+----------------------+
+   | :attr:`path`     | 2     | Hierarchical path        | empty string         |
+   +------------------+-------+--------------------------+----------------------+
+   | :attr:`params`   | 3     | Parameters for last path | empty string         |
+   |                  |       | element                  |                      |
+   +------------------+-------+--------------------------+----------------------+
+   | :attr:`query`    | 4     | Query component          | empty string         |
+   +------------------+-------+--------------------------+----------------------+
+   | :attr:`fragment` | 5     | Fragment identifier      | empty string         |
+   +------------------+-------+--------------------------+----------------------+
+   | :attr:`username` |       | User name                | :const:`None`        |
+   +------------------+-------+--------------------------+----------------------+
+   | :attr:`password` |       | Password                 | :const:`None`        |
+   +------------------+-------+--------------------------+----------------------+
+   | :attr:`hostname` |       | Host name (lower case)   | :const:`None`        |
+   +------------------+-------+--------------------------+----------------------+
+   | :attr:`port`     |       | Port number as integer,  | :const:`None`        |
+   |                  |       | if present               |                      |
+   +------------------+-------+--------------------------+----------------------+
+
+   See section :ref:`urlparse-result-object` for more information on the result
+   object.
+
+   .. versionchanged:: 2.5
+      Added attributes to return value.
+
+
+.. function:: urlunparse(parts)
+
+   Construct a URL from a tuple as returned by ``urlparse()``. The *parts* argument
+   can be any six-item iterable. This may result in a slightly different, but
+   equivalent URL, if the URL that was parsed originally had unnecessary delimiters
+   (for example, a ? with an empty query; the RFC states that these are
+   equivalent).
+
+
+.. function:: urlsplit(urlstring[, default_scheme[, allow_fragments]])
+
+   This is similar to :func:`urlparse`, but does not split the params from the URL.
+   This should generally be used instead of :func:`urlparse` if the more recent URL
+   syntax allowing parameters to be applied to each segment of the *path* portion
+   of the URL (see :rfc:`2396`) is wanted.  A separate function is needed to
+   separate the path segments and parameters.  This function returns a 5-tuple:
+   (addressing scheme, network location, path, query, fragment identifier).
+
+   The return value is actually an instance of a subclass of :class:`tuple`.  This
+   class has the following additional read-only convenience attributes:
+
+   +------------------+-------+-------------------------+----------------------+
+   | Attribute        | Index | Value                   | Value if not present |
+   +==================+=======+=========================+======================+
+   | :attr:`scheme`   | 0     | URL scheme specifier    | empty string         |
+   +------------------+-------+-------------------------+----------------------+
+   | :attr:`netloc`   | 1     | Network location part   | empty string         |
+   +------------------+-------+-------------------------+----------------------+
+   | :attr:`path`     | 2     | Hierarchical path       | empty string         |
+   +------------------+-------+-------------------------+----------------------+
+   | :attr:`query`    | 3     | Query component         | empty string         |
+   +------------------+-------+-------------------------+----------------------+
+   | :attr:`fragment` | 4     | Fragment identifier     | empty string         |
+   +------------------+-------+-------------------------+----------------------+
+   | :attr:`username` |       | User name               | :const:`None`        |
+   +------------------+-------+-------------------------+----------------------+
+   | :attr:`password` |       | Password                | :const:`None`        |
+   +------------------+-------+-------------------------+----------------------+
+   | :attr:`hostname` |       | Host name (lower case)  | :const:`None`        |
+   +------------------+-------+-------------------------+----------------------+
+   | :attr:`port`     |       | Port number as integer, | :const:`None`        |
+   |                  |       | if present              |                      |
+   +------------------+-------+-------------------------+----------------------+
+
+   See section :ref:`urlparse-result-object` for more information on the result
+   object.
+
+   .. versionadded:: 2.2
+
+   .. versionchanged:: 2.5
+      Added attributes to return value.
+
+
+.. function:: urlunsplit(parts)
+
+   Combine the elements of a tuple as returned by :func:`urlsplit` into a complete
+   URL as a string. The *parts* argument can be any five-item iterable. This may
+   result in a slightly different, but equivalent URL, if the URL that was parsed
+   originally had unnecessary delimiters (for example, a ? with an empty query; the
+   RFC states that these are equivalent).
+
+   .. versionadded:: 2.2
+
+
+.. function:: urljoin(base, url[, allow_fragments])
+
+   Construct a full ("absolute") URL by combining a "base URL" (*base*) with
+   another URL (*url*).  Informally, this uses components of the base URL, in
+   particular the addressing scheme, the network location and (part of) the path,
+   to provide missing components in the relative URL.  For example::
+
+      >>> from urlparse import urljoin
+      >>> urljoin('http://www.cwi.nl/%7Eguido/Python.html', 'FAQ.html')
+      'http://www.cwi.nl/%7Eguido/FAQ.html'
+
+   The *allow_fragments* argument has the same meaning and default as for
+   :func:`urlparse`.
+
+   .. note::
+
+      If *url* is an absolute URL (that is, starting with ``//`` or ``scheme://``),
+      the *url*'s host name and/or scheme will be present in the result.  For example:
+
+   ::
+
+      >>> urljoin('http://www.cwi.nl/%7Eguido/Python.html',
+      ...         '//www.python.org/%7Eguido')
+      'http://www.python.org/%7Eguido'
+
+   If you do not want that behavior, preprocess the *url* with :func:`urlsplit` and
+   :func:`urlunsplit`, removing possible *scheme* and *netloc* parts.
+
+
+.. function:: urldefrag(url)
+
+   If *url* contains a fragment identifier, returns a modified version of *url*
+   with no fragment identifier, and the fragment identifier as a separate string.
+   If there is no fragment identifier in *url*, returns *url* unmodified and an
+   empty string.
+
+
+.. seealso::
+
+   :rfc:`1738` - Uniform Resource Locators (URL)
+      This specifies the formal syntax and semantics of absolute URLs.
+
+   :rfc:`1808` - Relative Uniform Resource Locators
+      This Request For Comments includes the rules for joining an absolute and a
+      relative URL, including a fair number of "Abnormal Examples" which govern the
+      treatment of border cases.
+
+   :rfc:`2396` - Uniform Resource Identifiers (URI): Generic Syntax
+      Document describing the generic syntactic requirements for both Uniform Resource
+      Names (URNs) and Uniform Resource Locators (URLs).
+
+
+.. _urlparse-result-object:
+
+Results of :func:`urlparse` and :func:`urlsplit`
+------------------------------------------------
+
+The result objects from the :func:`urlparse` and :func:`urlsplit` functions are
+subclasses of the :class:`tuple` type.  These subclasses add the attributes
+described in those functions, as well as provide an additional method:
+
+
+.. method:: ParseResult.geturl()
+
+   Return the re-combined version of the original URL as a string. This may differ
+   from the original URL in that the scheme will always be normalized to lower case
+   and empty components may be dropped. Specifically, empty parameters, queries,
+   and fragment identifiers will be removed.
+
+   The result of this method is a fixpoint if passed back through the original
+   parsing function::
+
+      >>> import urlparse
+      >>> url = 'HTTP://www.Python.org/doc/#'
+
+      >>> r1 = urlparse.urlsplit(url)
+      >>> r1.geturl()
+      'http://www.Python.org/doc/'
+
+      >>> r2 = urlparse.urlsplit(r1.geturl())
+      >>> r2.geturl()
+      'http://www.Python.org/doc/'
+
+   .. versionadded:: 2.5
+
+The following classes provide the implementations of the parse results::
+
+
+.. class:: BaseResult
+
+   Base class for the concrete result classes.  This provides most of the attribute
+   definitions.  It does not provide a :meth:`geturl` method.  It is derived from
+   :class:`tuple`, but does not override the :meth:`__init__` or :meth:`__new__`
+   methods.
+
+
+.. class:: ParseResult(scheme, netloc, path, params, query, fragment)
+
+   Concrete class for :func:`urlparse` results.  The :meth:`__new__` method is
+   overridden to support checking that the right number of arguments are passed.
+
+
+.. class:: SplitResult(scheme, netloc, path, query, fragment)
+
+   Concrete class for :func:`urlsplit` results.  The :meth:`__new__` method is
+   overridden to support checking that the right number of arguments are passed.
+
diff --git a/Doc/library/user.rst b/Doc/library/user.rst
new file mode 100644
index 0000000..ba94262
--- /dev/null
+++ b/Doc/library/user.rst
@@ -0,0 +1,69 @@
+
+:mod:`user` --- User-specific configuration hook
+================================================
+
+.. module:: user
+   :synopsis: A standard way to reference user-specific modules.
+
+
+.. index::
+   pair: .pythonrc.py; file
+   triple: user; configuration; file
+
+As a policy, Python doesn't run user-specified code on startup of Python
+programs.  (Only interactive sessions execute the script specified in the
+:envvar:`PYTHONSTARTUP` environment variable if it exists).
+
+However, some programs or sites may find it convenient to allow users to have a
+standard customization file, which gets run when a program requests it.  This
+module implements such a mechanism.  A program that wishes to use the mechanism
+must execute the statement ::
+
+   import user
+
+.. index:: builtin: exec
+
+The :mod:`user` module looks for a file :file:`.pythonrc.py` in the user's home
+directory and if it can be opened, executes it (using :func:`exec`) in its
+own (the module :mod:`user`'s) global namespace.  Errors during this phase are
+not caught; that's up to the program that imports the :mod:`user` module, if it
+wishes.  The home directory is assumed to be named by the :envvar:`HOME`
+environment variable; if this is not set, the current directory is used.
+
+The user's :file:`.pythonrc.py` could conceivably test for ``sys.version`` if it
+wishes to do different things depending on the Python version.
+
+A warning to users: be very conservative in what you place in your
+:file:`.pythonrc.py` file.  Since you don't know which programs will use it,
+changing the behavior of standard modules or functions is generally not a good
+idea.
+
+A suggestion for programmers who wish to use this mechanism: a simple way to let
+users specify options for your package is to have them define variables in their
+:file:`.pythonrc.py` file that you test in your module.  For example, a module
+:mod:`spam` that has a verbosity level can look for a variable
+``user.spam_verbose``, as follows::
+
+   import user
+
+   verbose = bool(getattr(user, "spam_verbose", 0))
+
+(The three-argument form of :func:`getattr` is used in case the user has not
+defined ``spam_verbose`` in their :file:`.pythonrc.py` file.)
+
+Programs with extensive customization needs are better off reading a
+program-specific customization file.
+
+Programs with security or privacy concerns should *not* import this module; a
+user can easily break into a program by placing arbitrary code in the
+:file:`.pythonrc.py` file.
+
+Modules for general use should *not* import this module; it may interfere with
+the operation of the importing program.
+
+
+.. seealso::
+
+   Module :mod:`site`
+      Site-wide customization mechanism.
+
diff --git a/Doc/library/userdict.rst b/Doc/library/userdict.rst
new file mode 100644
index 0000000..11d46ed
--- /dev/null
+++ b/Doc/library/userdict.rst
@@ -0,0 +1,188 @@
+
+:mod:`UserDict` --- Class wrapper for dictionary objects
+========================================================
+
+.. module:: UserDict
+   :synopsis: Class wrapper for dictionary objects.
+
+
+The module defines a mixin,  :class:`DictMixin`, defining all dictionary methods
+for classes that already have a minimum mapping interface.  This greatly
+simplifies writing classes that need to be substitutable for dictionaries (such
+as the shelve module).
+
+This also module defines a class, :class:`UserDict`, that acts as a wrapper
+around dictionary objects.  The need for this class has been largely supplanted
+by the ability to subclass directly from :class:`dict` (a feature that became
+available starting with Python version 2.2).  Prior to the introduction of
+:class:`dict`, the :class:`UserDict` class was used to create dictionary-like
+sub-classes that obtained new behaviors by overriding existing methods or adding
+new ones.
+
+The :mod:`UserDict` module defines the :class:`UserDict` class and
+:class:`DictMixin`:
+
+
+.. class:: UserDict([initialdata])
+
+   Class that simulates a dictionary.  The instance's contents are kept in a
+   regular dictionary, which is accessible via the :attr:`data` attribute of
+   :class:`UserDict` instances.  If *initialdata* is provided, :attr:`data` is
+   initialized with its contents; note that a reference to *initialdata* will not
+   be kept, allowing it be used for other purposes.
+
+   .. note::
+
+      For backward compatibility, instances of :class:`UserDict` are not iterable.
+
+
+.. class:: IterableUserDict([initialdata])
+
+   Subclass of :class:`UserDict` that supports direct iteration (e.g.  ``for key in
+   myDict``).
+
+In addition to supporting the methods and operations of mappings (see section
+:ref:`typesmapping`), :class:`UserDict` and :class:`IterableUserDict` instances
+provide the following attribute:
+
+
+.. attribute:: IterableUserDict.data
+
+   A real dictionary used to store the contents of the :class:`UserDict` class.
+
+
+.. class:: DictMixin()
+
+   Mixin defining all dictionary methods for classes that already have a minimum
+   dictionary interface including :meth:`__getitem__`, :meth:`__setitem__`,
+   :meth:`__delitem__`, and :meth:`keys`.
+
+   This mixin should be used as a superclass.  Adding each of the above methods
+   adds progressively more functionality.  For instance, defining all but
+   :meth:`__delitem__` will preclude only :meth:`pop` and :meth:`popitem` from the
+   full interface.
+
+   In addition to the four base methods, progressively more efficiency comes with
+   defining :meth:`__contains__`, :meth:`__iter__`, and :meth:`iteritems`.
+
+   Since the mixin has no knowledge of the subclass constructor, it does not define
+   :meth:`__init__` or :meth:`copy`.
+
+
+:mod:`UserList` --- Class wrapper for list objects
+==================================================
+
+.. module:: UserList
+   :synopsis: Class wrapper for list objects.
+
+
+.. note::
+
+   This module is available for backward compatibility only.  If you are writing
+   code that does not need to work with versions of Python earlier than Python 2.2,
+   please consider subclassing directly from the built-in :class:`list` type.
+
+This module defines a class that acts as a wrapper around list objects.  It is a
+useful base class for your own list-like classes, which can inherit from them
+and override existing methods or add new ones.  In this way one can add new
+behaviors to lists.
+
+The :mod:`UserList` module defines the :class:`UserList` class:
+
+
+.. class:: UserList([list])
+
+   Class that simulates a list.  The instance's contents are kept in a regular
+   list, which is accessible via the :attr:`data` attribute of :class:`UserList`
+   instances.  The instance's contents are initially set to a copy of *list*,
+   defaulting to the empty list ``[]``.  *list* can be any iterable, e.g. a
+   real Python list or a :class:`UserList` object.
+
+In addition to supporting the methods and operations of mutable sequences (see
+section :ref:`typesseq`), :class:`UserList` instances provide the following
+attribute:
+
+
+.. attribute:: UserList.data
+
+   A real Python list object used to store the contents of the :class:`UserList`
+   class.
+
+**Subclassing requirements:** Subclasses of :class:`UserList` are expect to
+offer a constructor which can be called with either no arguments or one
+argument.  List operations which return a new sequence attempt to create an
+instance of the actual implementation class.  To do so, it assumes that the
+constructor can be called with a single parameter, which is a sequence object
+used as a data source.
+
+If a derived class does not wish to comply with this requirement, all of the
+special methods supported by this class will need to be overridden; please
+consult the sources for information about the methods which need to be provided
+in that case.
+
+.. versionchanged:: 2.0
+   Python versions 1.5.2 and 1.6 also required that the constructor be callable
+   with no parameters, and offer a mutable :attr:`data` attribute.  Earlier
+   versions of Python did not attempt to create instances of the derived class.
+
+
+:mod:`UserString` --- Class wrapper for string objects
+======================================================
+
+.. module:: UserString
+   :synopsis: Class wrapper for string objects.
+.. moduleauthor:: Peter Funk <pf@artcom-gmbh.de>
+.. sectionauthor:: Peter Funk <pf@artcom-gmbh.de>
+
+
+.. note::
+
+   This :class:`UserString` class from this module is available for backward
+   compatibility only.  If you are writing code that does not need to work with
+   versions of Python earlier than Python 2.2, please consider subclassing directly
+   from the built-in :class:`str` type instead of using :class:`UserString` (there
+   is no built-in equivalent to :class:`MutableString`).
+
+This module defines a class that acts as a wrapper around string objects.  It is
+a useful base class for your own string-like classes, which can inherit from
+them and override existing methods or add new ones.  In this way one can add new
+behaviors to strings.
+
+It should be noted that these classes are highly inefficient compared to real
+string or Unicode objects; this is especially the case for
+:class:`MutableString`.
+
+The :mod:`UserString` module defines the following classes:
+
+
+.. class:: UserString([sequence])
+
+   Class that simulates a string or a Unicode string object.  The instance's
+   content is kept in a regular string or Unicode string object, which is
+   accessible via the :attr:`data` attribute of :class:`UserString` instances.  The
+   instance's contents are initially set to a copy of *sequence*.  *sequence* can
+   be either a regular Python string or Unicode string, an instance of
+   :class:`UserString` (or a subclass) or an arbitrary sequence which can be
+   converted into a string using the built-in :func:`str` function.
+
+
+.. class:: MutableString([sequence])
+
+   This class is derived from the :class:`UserString` above and redefines strings
+   to be *mutable*.  Mutable strings can't be used as dictionary keys, because
+   dictionaries require *immutable* objects as keys.  The main intention of this
+   class is to serve as an educational example for inheritance and necessity to
+   remove (override) the :meth:`__hash__` method in order to trap attempts to use a
+   mutable object as dictionary key, which would be otherwise very error prone and
+   hard to track down.
+
+In addition to supporting the methods and operations of string and Unicode
+objects (see section :ref:`string-methods`), :class:`UserString` instances
+provide the following attribute:
+
+
+.. attribute:: MutableString.data
+
+   A real Python string or Unicode object used to store the content of the
+   :class:`UserString` class.
+
diff --git a/Doc/library/uu.rst b/Doc/library/uu.rst
new file mode 100644
index 0000000..e2303c3
--- /dev/null
+++ b/Doc/library/uu.rst
@@ -0,0 +1,60 @@
+
+:mod:`uu` --- Encode and decode uuencode files
+==============================================
+
+.. module:: uu
+   :synopsis: Encode and decode files in uuencode format.
+.. moduleauthor:: Lance Ellinghouse
+
+
+This module encodes and decodes files in uuencode format, allowing arbitrary
+binary data to be transferred over ASCII-only connections. Wherever a file
+argument is expected, the methods accept a file-like object.  For backwards
+compatibility, a string containing a pathname is also accepted, and the
+corresponding file will be opened for reading and writing; the pathname ``'-'``
+is understood to mean the standard input or output.  However, this interface is
+deprecated; it's better for the caller to open the file itself, and be sure
+that, when required, the mode is ``'rb'`` or ``'wb'`` on Windows.
+
+.. index::
+   single: Jansen, Jack
+   single: Ellinghouse, Lance
+
+This code was contributed by Lance Ellinghouse, and modified by Jack Jansen.
+
+The :mod:`uu` module defines the following functions:
+
+
+.. function:: encode(in_file, out_file[, name[, mode]])
+
+   Uuencode file *in_file* into file *out_file*.  The uuencoded file will have the
+   header specifying *name* and *mode* as the defaults for the results of decoding
+   the file. The default defaults are taken from *in_file*, or ``'-'`` and ``0666``
+   respectively.
+
+
+.. function:: decode(in_file[, out_file[, mode[, quiet]]])
+
+   This call decodes uuencoded file *in_file* placing the result on file
+   *out_file*. If *out_file* is a pathname, *mode* is used to set the permission
+   bits if the file must be created. Defaults for *out_file* and *mode* are taken
+   from the uuencode header.  However, if the file specified in the header already
+   exists, a :exc:`uu.Error` is raised.
+
+   :func:`decode` may print a warning to standard error if the input was produced
+   by an incorrect uuencoder and Python could recover from that error.  Setting
+   *quiet* to a true value silences this warning.
+
+
+.. exception:: Error()
+
+   Subclass of :exc:`Exception`, this can be raised by :func:`uu.decode` under
+   various situations, such as described above, but also including a badly
+   formatted header, or truncated input file.
+
+
+.. seealso::
+
+   Module :mod:`binascii`
+      Support module containing ASCII-to-binary and binary-to-ASCII conversions.
+
diff --git a/Doc/library/uuid.rst b/Doc/library/uuid.rst
new file mode 100644
index 0000000..dd52638
--- /dev/null
+++ b/Doc/library/uuid.rst
@@ -0,0 +1,258 @@
+
+:mod:`uuid` --- UUID objects according to RFC 4122
+==================================================
+
+.. module:: uuid
+   :synopsis: UUID objects (universally unique identifiers) according to RFC 4122
+.. moduleauthor:: Ka-Ping Yee <ping@zesty.ca>
+.. sectionauthor:: George Yoshida <quiver@users.sourceforge.net>
+
+
+.. versionadded:: 2.5
+
+This module provides immutable :class:`UUID` objects (the :class:`UUID` class)
+and the functions :func:`uuid1`, :func:`uuid3`, :func:`uuid4`, :func:`uuid5` for
+generating version 1, 3, 4, and 5 UUIDs as specified in :rfc:`4122`.
+
+If all you want is a unique ID, you should probably call :func:`uuid1` or
+:func:`uuid4`.  Note that :func:`uuid1` may compromise privacy since it creates
+a UUID containing the computer's network address.  :func:`uuid4` creates a
+random UUID.
+
+
+.. class:: UUID([hex[, bytes[, bytes_le[, fields[, int[, version]]]]]])
+
+   Create a UUID from either a string of 32 hexadecimal digits, a string of 16
+   bytes as the *bytes* argument, a string of 16 bytes in little-endian order as
+   the *bytes_le* argument, a tuple of six integers (32-bit *time_low*, 16-bit
+   *time_mid*, 16-bit *time_hi_version*, 8-bit *clock_seq_hi_variant*, 8-bit
+   *clock_seq_low*, 48-bit *node*) as the *fields* argument, or a single 128-bit
+   integer as the *int* argument.  When a string of hex digits is given, curly
+   braces, hyphens, and a URN prefix are all optional.  For example, these
+   expressions all yield the same UUID::
+
+      UUID('{12345678-1234-5678-1234-567812345678}')
+      UUID('12345678123456781234567812345678')
+      UUID('urn:uuid:12345678-1234-5678-1234-567812345678')
+      UUID(bytes='\x12\x34\x56\x78'*4)
+      UUID(bytes_le='\x78\x56\x34\x12\x34\x12\x78\x56' +
+                    '\x12\x34\x56\x78\x12\x34\x56\x78')
+      UUID(fields=(0x12345678, 0x1234, 0x5678, 0x12, 0x34, 0x567812345678))
+      UUID(int=0x12345678123456781234567812345678)
+
+   Exactly one of *hex*, *bytes*, *bytes_le*, *fields*, or *int* must be given.
+   The *version* argument is optional; if given, the resulting UUID will have its
+   variant and version number set according to RFC 4122, overriding bits in the
+   given *hex*, *bytes*, *bytes_le*, *fields*, or *int*.
+
+:class:`UUID` instances have these read-only attributes:
+
+
+.. attribute:: UUID.bytes
+
+   The UUID as a 16-byte string (containing the six integer fields in big-endian
+   byte order).
+
+
+.. attribute:: UUID.bytes_le
+
+   The UUID as a 16-byte string (with *time_low*, *time_mid*, and *time_hi_version*
+   in little-endian byte order).
+
+
+.. attribute:: UUID.fields
+
+   A tuple of the six integer fields of the UUID, which are also available as six
+   individual attributes and two derived attributes:
+
+   +------------------------------+-------------------------------+
+   | Field                        | Meaning                       |
+   +==============================+===============================+
+   | :attr:`time_low`             | the first 32 bits of the UUID |
+   +------------------------------+-------------------------------+
+   | :attr:`time_mid`             | the next 16 bits of the UUID  |
+   +------------------------------+-------------------------------+
+   | :attr:`time_hi_version`      | the next 16 bits of the UUID  |
+   +------------------------------+-------------------------------+
+   | :attr:`clock_seq_hi_variant` | the next 8 bits of the UUID   |
+   +------------------------------+-------------------------------+
+   | :attr:`clock_seq_low`        | the next 8 bits of the UUID   |
+   +------------------------------+-------------------------------+
+   | :attr:`node`                 | the last 48 bits of the UUID  |
+   +------------------------------+-------------------------------+
+   | :attr:`time`                 | the 60-bit timestamp          |
+   +------------------------------+-------------------------------+
+   | :attr:`clock_seq`            | the 14-bit sequence number    |
+   +------------------------------+-------------------------------+
+
+
+.. attribute:: UUID.hex
+
+   The UUID as a 32-character hexadecimal string.
+
+
+.. attribute:: UUID.int
+
+   The UUID as a 128-bit integer.
+
+
+.. attribute:: UUID.urn
+
+   The UUID as a URN as specified in RFC 4122.
+
+
+.. attribute:: UUID.variant
+
+   The UUID variant, which determines the internal layout of the UUID. This will be
+   one of the integer constants :const:`RESERVED_NCS`, :const:`RFC_4122`,
+   :const:`RESERVED_MICROSOFT`, or :const:`RESERVED_FUTURE`.
+
+
+.. attribute:: UUID.version
+
+   The UUID version number (1 through 5, meaningful only when the variant is
+   :const:`RFC_4122`).
+
+The :mod:`uuid` module defines the following functions:
+
+
+.. function:: getnode()
+
+   Get the hardware address as a 48-bit positive integer.  The first time this
+   runs, it may launch a separate program, which could be quite slow.  If all
+   attempts to obtain the hardware address fail, we choose a random 48-bit number
+   with its eighth bit set to 1 as recommended in RFC 4122.  "Hardware address"
+   means the MAC address of a network interface, and on a machine with multiple
+   network interfaces the MAC address of any one of them may be returned.
+
+.. index:: single: getnode
+
+
+.. function:: uuid1([node[, clock_seq]])
+
+   Generate a UUID from a host ID, sequence number, and the current time. If *node*
+   is not given, :func:`getnode` is used to obtain the hardware address. If
+   *clock_seq* is given, it is used as the sequence number; otherwise a random
+   14-bit sequence number is chosen.
+
+.. index:: single: uuid1
+
+
+.. function:: uuid3(namespace, name)
+
+   Generate a UUID based on the MD5 hash of a namespace identifier (which is a
+   UUID) and a name (which is a string).
+
+.. index:: single: uuid3
+
+
+.. function:: uuid4()
+
+   Generate a random UUID.
+
+.. index:: single: uuid4
+
+
+.. function:: uuid5(namespace, name)
+
+   Generate a UUID based on the SHA-1 hash of a namespace identifier (which is a
+   UUID) and a name (which is a string).
+
+.. index:: single: uuid5
+
+The :mod:`uuid` module defines the following namespace identifiers for use with
+:func:`uuid3` or :func:`uuid5`.
+
+
+.. data:: NAMESPACE_DNS
+
+   When this namespace is specified, the *name* string is a fully-qualified domain
+   name.
+
+
+.. data:: NAMESPACE_URL
+
+   When this namespace is specified, the *name* string is a URL.
+
+
+.. data:: NAMESPACE_OID
+
+   When this namespace is specified, the *name* string is an ISO OID.
+
+
+.. data:: NAMESPACE_X500
+
+   When this namespace is specified, the *name* string is an X.500 DN in DER or a
+   text output format.
+
+The :mod:`uuid` module defines the following constants for the possible values
+of the :attr:`variant` attribute:
+
+
+.. data:: RESERVED_NCS
+
+   Reserved for NCS compatibility.
+
+
+.. data:: RFC_4122
+
+   Specifies the UUID layout given in :rfc:`4122`.
+
+
+.. data:: RESERVED_MICROSOFT
+
+   Reserved for Microsoft compatibility.
+
+
+.. data:: RESERVED_FUTURE
+
+   Reserved for future definition.
+
+
+.. seealso::
+
+   :rfc:`4122` - A Universally Unique IDentifier (UUID) URN Namespace
+      This specification defines a Uniform Resource Name namespace for UUIDs, the
+      internal format of UUIDs, and methods of generating UUIDs.
+
+
+.. _uuid-example:
+
+Example
+-------
+
+Here are some examples of typical usage of the :mod:`uuid` module::
+
+   >>> import uuid
+
+   # make a UUID based on the host ID and current time
+   >>> uuid.uuid1()
+   UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')
+
+   # make a UUID using an MD5 hash of a namespace UUID and a name
+   >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
+   UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')
+
+   # make a random UUID
+   >>> uuid.uuid4()
+   UUID('16fd2706-8baf-433b-82eb-8c7fada847da')
+
+   # make a UUID using a SHA-1 hash of a namespace UUID and a name
+   >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
+   UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')
+
+   # make a UUID from a string of hex digits (braces and hyphens ignored)
+   >>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}')
+
+   # convert a UUID to a string of hex digits in standard form
+   >>> str(x)
+   '00010203-0405-0607-0809-0a0b0c0d0e0f'
+
+   # get the raw 16 bytes of the UUID
+   >>> x.bytes
+   '\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f'
+
+   # make a UUID from a 16-byte string
+   >>> uuid.UUID(bytes=x.bytes)
+   UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')
+
diff --git a/Doc/library/warnings.rst b/Doc/library/warnings.rst
new file mode 100644
index 0000000..35e9888
--- /dev/null
+++ b/Doc/library/warnings.rst
@@ -0,0 +1,242 @@
+
+:mod:`warnings` --- Warning control
+===================================
+
+.. index:: single: warnings
+
+.. module:: warnings
+   :synopsis: Issue warning messages and control their disposition.
+
+
+.. versionadded:: 2.1
+
+Warning messages are typically issued in situations where it is useful to alert
+the user of some condition in a program, where that condition (normally) doesn't
+warrant raising an exception and terminating the program.  For example, one
+might want to issue a warning when a program uses an obsolete module.
+
+Python programmers issue warnings by calling the :func:`warn` function defined
+in this module.  (C programmers use :cfunc:`PyErr_WarnEx`; see
+:ref:`exceptionhandling` for details).
+
+Warning messages are normally written to ``sys.stderr``, but their disposition
+can be changed flexibly, from ignoring all warnings to turning them into
+exceptions.  The disposition of warnings can vary based on the warning category
+(see below), the text of the warning message, and the source location where it
+is issued.  Repetitions of a particular warning for the same source location are
+typically suppressed.
+
+There are two stages in warning control: first, each time a warning is issued, a
+determination is made whether a message should be issued or not; next, if a
+message is to be issued, it is formatted and printed using a user-settable hook.
+
+The determination whether to issue a warning message is controlled by the
+warning filter, which is a sequence of matching rules and actions. Rules can be
+added to the filter by calling :func:`filterwarnings` and reset to its default
+state by calling :func:`resetwarnings`.
+
+The printing of warning messages is done by calling :func:`showwarning`, which
+may be overridden; the default implementation of this function formats the
+message by calling :func:`formatwarning`, which is also available for use by
+custom implementations.
+
+
+.. _warning-categories:
+
+Warning Categories
+------------------
+
+There are a number of built-in exceptions that represent warning categories.
+This categorization is useful to be able to filter out groups of warnings.  The
+following warnings category classes are currently defined:
+
++----------------------------------+-----------------------------------------------+
+| Class                            | Description                                   |
++==================================+===============================================+
+| :exc:`Warning`                   | This is the base class of all warning         |
+|                                  | category classes.  It is a subclass of        |
+|                                  | :exc:`Exception`.                             |
++----------------------------------+-----------------------------------------------+
+| :exc:`UserWarning`               | The default category for :func:`warn`.        |
++----------------------------------+-----------------------------------------------+
+| :exc:`DeprecationWarning`        | Base category for warnings about deprecated   |
+|                                  | features.                                     |
++----------------------------------+-----------------------------------------------+
+| :exc:`SyntaxWarning`             | Base category for warnings about dubious      |
+|                                  | syntactic features.                           |
++----------------------------------+-----------------------------------------------+
+| :exc:`RuntimeWarning`            | Base category for warnings about dubious      |
+|                                  | runtime features.                             |
++----------------------------------+-----------------------------------------------+
+| :exc:`FutureWarning`             | Base category for warnings about constructs   |
+|                                  | that will change semantically in the future.  |
++----------------------------------+-----------------------------------------------+
+| :exc:`PendingDeprecationWarning` | Base category for warnings about features     |
+|                                  | that will be deprecated in the future         |
+|                                  | (ignored by default).                         |
++----------------------------------+-----------------------------------------------+
+| :exc:`ImportWarning`             | Base category for warnings triggered during   |
+|                                  | the process of importing a module (ignored by |
+|                                  | default).                                     |
++----------------------------------+-----------------------------------------------+
+| :exc:`UnicodeWarning`            | Base category for warnings related to         |
+|                                  | Unicode.                                      |
++----------------------------------+-----------------------------------------------+
+
+While these are technically built-in exceptions, they are documented here,
+because conceptually they belong to the warnings mechanism.
+
+User code can define additional warning categories by subclassing one of the
+standard warning categories.  A warning category must always be a subclass of
+the :exc:`Warning` class.
+
+
+.. _warning-filter:
+
+The Warnings Filter
+-------------------
+
+The warnings filter controls whether warnings are ignored, displayed, or turned
+into errors (raising an exception).
+
+Conceptually, the warnings filter maintains an ordered list of filter
+specifications; any specific warning is matched against each filter
+specification in the list in turn until a match is found; the match determines
+the disposition of the match.  Each entry is a tuple of the form (*action*,
+*message*, *category*, *module*, *lineno*), where:
+
+* *action* is one of the following strings:
+
+  +---------------+----------------------------------------------+
+  | Value         | Disposition                                  |
+  +===============+==============================================+
+  | ``"error"``   | turn matching warnings into exceptions       |
+  +---------------+----------------------------------------------+
+  | ``"ignore"``  | never print matching warnings                |
+  +---------------+----------------------------------------------+
+  | ``"always"``  | always print matching warnings               |
+  +---------------+----------------------------------------------+
+  | ``"default"`` | print the first occurrence of matching       |
+  |               | warnings for each location where the warning |
+  |               | is issued                                    |
+  +---------------+----------------------------------------------+
+  | ``"module"``  | print the first occurrence of matching       |
+  |               | warnings for each module where the warning   |
+  |               | is issued                                    |
+  +---------------+----------------------------------------------+
+  | ``"once"``    | print only the first occurrence of matching  |
+  |               | warnings, regardless of location             |
+  +---------------+----------------------------------------------+
+
+* *message* is a string containing a regular expression that the warning message
+  must match (the match is compiled to always be  case-insensitive)
+
+* *category* is a class (a subclass of :exc:`Warning`) of which the warning
+  category must be a subclass in order to match
+
+* *module* is a string containing a regular expression that the module name must
+  match (the match is compiled to be case-sensitive)
+
+* *lineno* is an integer that the line number where the warning occurred must
+  match, or ``0`` to match all line numbers
+
+Since the :exc:`Warning` class is derived from the built-in :exc:`Exception`
+class, to turn a warning into an error we simply raise ``category(message)``.
+
+The warnings filter is initialized by :option:`-W` options passed to the Python
+interpreter command line.  The interpreter saves the arguments for all
+:option:`-W` options without interpretation in ``sys.warnoptions``; the
+:mod:`warnings` module parses these when it is first imported (invalid options
+are ignored, after printing a message to ``sys.stderr``).
+
+The warnings that are ignored by default may be enabled by passing :option:`-Wd`
+to the interpreter. This enables default handling for all warnings, including
+those that are normally ignored by default. This is particular useful for
+enabling ImportWarning when debugging problems importing a developed package.
+ImportWarning can also be enabled explicitly in Python code using::
+
+   warnings.simplefilter('default', ImportWarning)
+
+
+.. _warning-functions:
+
+Available Functions
+-------------------
+
+
+.. function:: warn(message[, category[, stacklevel]])
+
+   Issue a warning, or maybe ignore it or raise an exception.  The *category*
+   argument, if given, must be a warning category class (see above); it defaults to
+   :exc:`UserWarning`.  Alternatively *message* can be a :exc:`Warning` instance,
+   in which case *category* will be ignored and ``message.__class__`` will be used.
+   In this case the message text will be ``str(message)``. This function raises an
+   exception if the particular warning issued is changed into an error by the
+   warnings filter see above.  The *stacklevel* argument can be used by wrapper
+   functions written in Python, like this::
+
+      def deprecation(message):
+          warnings.warn(message, DeprecationWarning, stacklevel=2)
+
+   This makes the warning refer to :func:`deprecation`'s caller, rather than to the
+   source of :func:`deprecation` itself (since the latter would defeat the purpose
+   of the warning message).
+
+
+.. function:: warn_explicit(message, category, filename, lineno[, module[, registry[, module_globals]]])
+
+   This is a low-level interface to the functionality of :func:`warn`, passing in
+   explicitly the message, category, filename and line number, and optionally the
+   module name and the registry (which should be the ``__warningregistry__``
+   dictionary of the module).  The module name defaults to the filename with
+   ``.py`` stripped; if no registry is passed, the warning is never suppressed.
+   *message* must be a string and *category* a subclass of :exc:`Warning` or
+   *message* may be a :exc:`Warning` instance, in which case *category* will be
+   ignored.
+
+   *module_globals*, if supplied, should be the global namespace in use by the code
+   for which the warning is issued.  (This argument is used to support displaying
+   source for modules found in zipfiles or other non-filesystem import sources, and
+   was added in Python 2.5.)
+
+
+.. function:: showwarning(message, category, filename, lineno[, file])
+
+   Write a warning to a file.  The default implementation calls
+   ``formatwarning(message, category, filename, lineno)`` and writes the resulting
+   string to *file*, which defaults to ``sys.stderr``.  You may replace this
+   function with an alternative implementation by assigning to
+   ``warnings.showwarning``.
+
+
+.. function:: formatwarning(message, category, filename, lineno)
+
+   Format a warning the standard way.  This returns a string  which may contain
+   embedded newlines and ends in a newline.
+
+
+.. function:: filterwarnings(action[, message[, category[, module[, lineno[, append]]]]])
+
+   Insert an entry into the list of warnings filters.  The entry is inserted at the
+   front by default; if *append* is true, it is inserted at the end. This checks
+   the types of the arguments, compiles the message and module regular expressions,
+   and inserts them as a tuple in the  list of warnings filters.  Entries closer to
+   the front of the list override entries later in the list, if both match a
+   particular warning.  Omitted arguments default to a value that matches
+   everything.
+
+
+.. function:: simplefilter(action[, category[, lineno[, append]]])
+
+   Insert a simple entry into the list of warnings filters. The meaning of the
+   function parameters is as for :func:`filterwarnings`, but regular expressions
+   are not needed as the filter inserted always matches any message in any module
+   as long as the category and line number match.
+
+
+.. function:: resetwarnings()
+
+   Reset the warnings filter.  This discards the effect of all previous calls to
+   :func:`filterwarnings`, including that of the :option:`-W` command line options
+   and calls to :func:`simplefilter`.
+
diff --git a/Doc/library/wave.rst b/Doc/library/wave.rst
new file mode 100644
index 0000000..d03f091
--- /dev/null
+++ b/Doc/library/wave.rst
@@ -0,0 +1,201 @@
+.. % Documentations stolen and LaTeX'ed from comments in file.
+
+
+:mod:`wave` --- Read and write WAV files
+========================================
+
+.. module:: wave
+   :synopsis: Provide an interface to the WAV sound format.
+.. sectionauthor:: Moshe Zadka <moshez@zadka.site.co.il>
+
+
+The :mod:`wave` module provides a convenient interface to the WAV sound format.
+It does not support compression/decompression, but it does support mono/stereo.
+
+The :mod:`wave` module defines the following function and exception:
+
+
+.. function:: open(file[, mode])
+
+   If *file* is a string, open the file by that name, other treat it as a seekable
+   file-like object. *mode* can be any of
+
+   ``'r'``, ``'rb'``
+      Read only mode.
+
+   ``'w'``, ``'wb'``
+      Write only mode.
+
+   Note that it does not allow read/write WAV files.
+
+   A *mode* of ``'r'`` or ``'rb'`` returns a :class:`Wave_read` object, while a
+   *mode* of ``'w'`` or ``'wb'`` returns a :class:`Wave_write` object.  If *mode*
+   is omitted and a file-like  object is passed as *file*, ``file.mode`` is used as
+   the default value for *mode* (the ``'b'`` flag is still added if  necessary).
+
+
+.. function:: openfp(file, mode)
+
+   A synonym for :func:`open`, maintained for backwards compatibility.
+
+
+.. exception:: Error
+
+   An error raised when something is impossible because it violates the WAV
+   specification or hits an implementation deficiency.
+
+
+.. _wave-read-objects:
+
+Wave_read Objects
+-----------------
+
+Wave_read objects, as returned by :func:`open`, have the following methods:
+
+
+.. method:: Wave_read.close()
+
+   Close the stream, and make the instance unusable. This is called automatically
+   on object collection.
+
+
+.. method:: Wave_read.getnchannels()
+
+   Returns number of audio channels (``1`` for mono, ``2`` for stereo).
+
+
+.. method:: Wave_read.getsampwidth()
+
+   Returns sample width in bytes.
+
+
+.. method:: Wave_read.getframerate()
+
+   Returns sampling frequency.
+
+
+.. method:: Wave_read.getnframes()
+
+   Returns number of audio frames.
+
+
+.. method:: Wave_read.getcomptype()
+
+   Returns compression type (``'NONE'`` is the only supported type).
+
+
+.. method:: Wave_read.getcompname()
+
+   Human-readable version of :meth:`getcomptype`. Usually ``'not compressed'``
+   parallels ``'NONE'``.
+
+
+.. method:: Wave_read.getparams()
+
+   Returns a tuple ``(nchannels, sampwidth, framerate, nframes, comptype,
+   compname)``, equivalent to output of the :meth:`get\*` methods.
+
+
+.. method:: Wave_read.readframes(n)
+
+   Reads and returns at most *n* frames of audio, as a string of bytes.
+
+
+.. method:: Wave_read.rewind()
+
+   Rewind the file pointer to the beginning of the audio stream.
+
+The following two methods are defined for compatibility with the :mod:`aifc`
+module, and don't do anything interesting.
+
+
+.. method:: Wave_read.getmarkers()
+
+   Returns ``None``.
+
+
+.. method:: Wave_read.getmark(id)
+
+   Raise an error.
+
+The following two methods define a term "position" which is compatible between
+them, and is otherwise implementation dependent.
+
+
+.. method:: Wave_read.setpos(pos)
+
+   Set the file pointer to the specified position.
+
+
+.. method:: Wave_read.tell()
+
+   Return current file pointer position.
+
+
+.. _wave-write-objects:
+
+Wave_write Objects
+------------------
+
+Wave_write objects, as returned by :func:`open`, have the following methods:
+
+
+.. method:: Wave_write.close()
+
+   Make sure *nframes* is correct, and close the file. This method is called upon
+   deletion.
+
+
+.. method:: Wave_write.setnchannels(n)
+
+   Set the number of channels.
+
+
+.. method:: Wave_write.setsampwidth(n)
+
+   Set the sample width to *n* bytes.
+
+
+.. method:: Wave_write.setframerate(n)
+
+   Set the frame rate to *n*.
+
+
+.. method:: Wave_write.setnframes(n)
+
+   Set the number of frames to *n*. This will be changed later if more frames are
+   written.
+
+
+.. method:: Wave_write.setcomptype(type, name)
+
+   Set the compression type and description. At the moment, only compression type
+   ``NONE`` is supported, meaning no compression.
+
+
+.. method:: Wave_write.setparams(tuple)
+
+   The *tuple* should be ``(nchannels, sampwidth, framerate, nframes, comptype,
+   compname)``, with values valid for the :meth:`set\*` methods.  Sets all
+   parameters.
+
+
+.. method:: Wave_write.tell()
+
+   Return current position in the file, with the same disclaimer for the
+   :meth:`Wave_read.tell` and :meth:`Wave_read.setpos` methods.
+
+
+.. method:: Wave_write.writeframesraw(data)
+
+   Write audio frames, without correcting *nframes*.
+
+
+.. method:: Wave_write.writeframes(data)
+
+   Write audio frames and make sure *nframes* is correct.
+
+Note that it is invalid to set any parameters after calling :meth:`writeframes`
+or :meth:`writeframesraw`, and any attempt to do so will raise
+:exc:`wave.Error`.
+
diff --git a/Doc/library/weakref.rst b/Doc/library/weakref.rst
new file mode 100644
index 0000000..c5857ba
--- /dev/null
+++ b/Doc/library/weakref.rst
@@ -0,0 +1,330 @@
+
+:mod:`weakref` --- Weak references
+==================================
+
+.. module:: weakref
+   :synopsis: Support for weak references and weak dictionaries.
+.. moduleauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+.. moduleauthor:: Neil Schemenauer <nas@arctrix.com>
+.. moduleauthor:: Martin von Löwis <martin@loewis.home.cs.tu-berlin.de>
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+.. versionadded:: 2.1
+
+The :mod:`weakref` module allows the Python programmer to create :dfn:`weak
+references` to objects.
+
+.. % When making changes to the examples in this file, be sure to update
+.. % Lib/test/test_weakref.py::libreftest too!
+
+In the following, the term :dfn:`referent` means the object which is referred to
+by a weak reference.
+
+A weak reference to an object is not enough to keep the object alive: when the
+only remaining references to a referent are weak references, garbage collection
+is free to destroy the referent and reuse its memory for something else.  A
+primary use for weak references is to implement caches or mappings holding large
+objects, where it's desired that a large object not be kept alive solely because
+it appears in a cache or mapping.  For example, if you have a number of large
+binary image objects, you may wish to associate a name with each.  If you used a
+Python dictionary to map names to images, or images to names, the image objects
+would remain alive just because they appeared as values or keys in the
+dictionaries.  The :class:`WeakKeyDictionary` and :class:`WeakValueDictionary`
+classes supplied by the :mod:`weakref` module are an alternative, using weak
+references to construct mappings that don't keep objects alive solely because
+they appear in the mapping objects.  If, for example, an image object is a value
+in a :class:`WeakValueDictionary`, then when the last remaining references to
+that image object are the weak references held by weak mappings, garbage
+collection can reclaim the object, and its corresponding entries in weak
+mappings are simply deleted.
+
+:class:`WeakKeyDictionary` and :class:`WeakValueDictionary` use weak references
+in their implementation, setting up callback functions on the weak references
+that notify the weak dictionaries when a key or value has been reclaimed by
+garbage collection.  Most programs should find that using one of these weak
+dictionary types is all they need -- it's not usually necessary to create your
+own weak references directly.  The low-level machinery used by the weak
+dictionary implementations is exposed by the :mod:`weakref` module for the
+benefit of advanced uses.
+
+Not all objects can be weakly referenced; those objects which can include class
+instances, functions written in Python (but not in C), methods (both bound and
+unbound), sets, frozensets, file objects, generators, type objects, DBcursor
+objects from the :mod:`bsddb` module, sockets, arrays, deques, and regular
+expression pattern objects.
+
+.. versionchanged:: 2.4
+   Added support for files, sockets, arrays, and patterns.
+
+Several builtin types such as :class:`list` and :class:`dict` do not directly
+support weak references but can add support through subclassing::
+
+   class Dict(dict):
+       pass
+
+   obj = Dict(red=1, green=2, blue=3)   # this object is weak referencable
+
+Extension types can easily be made to support weak references; see
+:ref:`weakref-support`.
+
+
+.. class:: ref(object[, callback])
+
+   Return a weak reference to *object*.  The original object can be retrieved by
+   calling the reference object if the referent is still alive; if the referent is
+   no longer alive, calling the reference object will cause :const:`None` to be
+   returned.  If *callback* is provided and not :const:`None`, and the returned
+   weakref object is still alive, the callback will be called when the object is
+   about to be finalized; the weak reference object will be passed as the only
+   parameter to the callback; the referent will no longer be available.
+
+   It is allowable for many weak references to be constructed for the same object.
+   Callbacks registered for each weak reference will be called from the most
+   recently registered callback to the oldest registered callback.
+
+   Exceptions raised by the callback will be noted on the standard error output,
+   but cannot be propagated; they are handled in exactly the same way as exceptions
+   raised from an object's :meth:`__del__` method.
+
+   Weak references are hashable if the *object* is hashable.  They will maintain
+   their hash value even after the *object* was deleted.  If :func:`hash` is called
+   the first time only after the *object* was deleted, the call will raise
+   :exc:`TypeError`.
+
+   Weak references support tests for equality, but not ordering.  If the referents
+   are still alive, two references have the same equality relationship as their
+   referents (regardless of the *callback*).  If either referent has been deleted,
+   the references are equal only if the reference objects are the same object.
+
+   .. versionchanged:: 2.4
+      This is now a subclassable type rather than a factory function; it derives from
+      :class:`object`.
+
+
+.. function:: proxy(object[, callback])
+
+   Return a proxy to *object* which uses a weak reference.  This supports use of
+   the proxy in most contexts instead of requiring the explicit dereferencing used
+   with weak reference objects.  The returned object will have a type of either
+   ``ProxyType`` or ``CallableProxyType``, depending on whether *object* is
+   callable.  Proxy objects are not hashable regardless of the referent; this
+   avoids a number of problems related to their fundamentally mutable nature, and
+   prevent their use as dictionary keys.  *callback* is the same as the parameter
+   of the same name to the :func:`ref` function.
+
+
+.. function:: getweakrefcount(object)
+
+   Return the number of weak references and proxies which refer to *object*.
+
+
+.. function:: getweakrefs(object)
+
+   Return a list of all weak reference and proxy objects which refer to *object*.
+
+
+.. class:: WeakKeyDictionary([dict])
+
+   Mapping class that references keys weakly.  Entries in the dictionary will be
+   discarded when there is no longer a strong reference to the key.  This can be
+   used to associate additional data with an object owned by other parts of an
+   application without adding attributes to those objects.  This can be especially
+   useful with objects that override attribute accesses.
+
+   .. note::
+
+      Caution:  Because a :class:`WeakKeyDictionary` is built on top of a Python
+      dictionary, it must not change size when iterating over it.  This can be
+      difficult to ensure for a :class:`WeakKeyDictionary` because actions performed
+      by the program during iteration may cause items in the dictionary to vanish "by
+      magic" (as a side effect of garbage collection).
+
+:class:`WeakKeyDictionary` objects have the following additional methods.  These
+expose the internal references directly.  The references are not guaranteed to
+be "live" at the time they are used, so the result of calling the references
+needs to be checked before being used.  This can be used to avoid creating
+references that will cause the garbage collector to keep the keys around longer
+than needed.
+
+
+.. method:: WeakKeyDictionary.iterkeyrefs()
+
+   Return an iterator that yields the weak references to the keys.
+
+   .. versionadded:: 2.5
+
+
+.. method:: WeakKeyDictionary.keyrefs()
+
+   Return a list of weak references to the keys.
+
+   .. versionadded:: 2.5
+
+
+.. class:: WeakValueDictionary([dict])
+
+   Mapping class that references values weakly.  Entries in the dictionary will be
+   discarded when no strong reference to the value exists any more.
+
+   .. note::
+
+      Caution:  Because a :class:`WeakValueDictionary` is built on top of a Python
+      dictionary, it must not change size when iterating over it.  This can be
+      difficult to ensure for a :class:`WeakValueDictionary` because actions performed
+      by the program during iteration may cause items in the dictionary to vanish "by
+      magic" (as a side effect of garbage collection).
+
+:class:`WeakValueDictionary` objects have the following additional methods.
+These method have the same issues as the :meth:`iterkeyrefs` and :meth:`keyrefs`
+methods of :class:`WeakKeyDictionary` objects.
+
+
+.. method:: WeakValueDictionary.itervaluerefs()
+
+   Return an iterator that yields the weak references to the values.
+
+   .. versionadded:: 2.5
+
+
+.. method:: WeakValueDictionary.valuerefs()
+
+   Return a list of weak references to the values.
+
+   .. versionadded:: 2.5
+
+
+.. data:: ReferenceType
+
+   The type object for weak references objects.
+
+
+.. data:: ProxyType
+
+   The type object for proxies of objects which are not callable.
+
+
+.. data:: CallableProxyType
+
+   The type object for proxies of callable objects.
+
+
+.. data:: ProxyTypes
+
+   Sequence containing all the type objects for proxies.  This can make it simpler
+   to test if an object is a proxy without being dependent on naming both proxy
+   types.
+
+
+.. exception:: ReferenceError
+
+   Exception raised when a proxy object is used but the underlying object has been
+   collected.  This is the same as the standard :exc:`ReferenceError` exception.
+
+
+.. seealso::
+
+   :pep:`0205` - Weak References
+      The proposal and rationale for this feature, including links to earlier
+      implementations and information about similar features in other languages.
+
+
+.. _weakref-objects:
+
+Weak Reference Objects
+----------------------
+
+Weak reference objects have no attributes or methods, but do allow the referent
+to be obtained, if it still exists, by calling it::
+
+   >>> import weakref
+   >>> class Object:
+   ...     pass
+   ...
+   >>> o = Object()
+   >>> r = weakref.ref(o)
+   >>> o2 = r()
+   >>> o is o2
+   True
+
+If the referent no longer exists, calling the reference object returns
+:const:`None`::
+
+   >>> del o, o2
+   >>> print r()
+   None
+
+Testing that a weak reference object is still live should be done using the
+expression ``ref() is not None``.  Normally, application code that needs to use
+a reference object should follow this pattern::
+
+   # r is a weak reference object
+   o = r()
+   if o is None:
+       # referent has been garbage collected
+       print "Object has been deallocated; can't frobnicate."
+   else:
+       print "Object is still live!"
+       o.do_something_useful()
+
+Using a separate test for "liveness" creates race conditions in threaded
+applications; another thread can cause a weak reference to become invalidated
+before the weak reference is called; the idiom shown above is safe in threaded
+applications as well as single-threaded applications.
+
+Specialized versions of :class:`ref` objects can be created through subclassing.
+This is used in the implementation of the :class:`WeakValueDictionary` to reduce
+the memory overhead for each entry in the mapping.  This may be most useful to
+associate additional information with a reference, but could also be used to
+insert additional processing on calls to retrieve the referent.
+
+This example shows how a subclass of :class:`ref` can be used to store
+additional information about an object and affect the value that's returned when
+the referent is accessed::
+
+   import weakref
+
+   class ExtendedRef(weakref.ref):
+       def __init__(self, ob, callback=None, **annotations):
+           super(ExtendedRef, self).__init__(ob, callback)
+           self.__counter = 0
+           for k, v in annotations.iteritems():
+               setattr(self, k, v)
+
+       def __call__(self):
+           """Return a pair containing the referent and the number of
+           times the reference has been called.
+           """
+           ob = super(ExtendedRef, self).__call__()
+           if ob is not None:
+               self.__counter += 1
+               ob = (ob, self.__counter)
+           return ob
+
+
+.. _weakref-example:
+
+Example
+-------
+
+This simple example shows how an application can use objects IDs to retrieve
+objects that it has seen before.  The IDs of the objects can then be used in
+other data structures without forcing the objects to remain alive, but the
+objects can still be retrieved by ID if they do.
+
+.. % Example contributed by Tim Peters.
+
+::
+
+   import weakref
+
+   _id2obj_dict = weakref.WeakValueDictionary()
+
+   def remember(obj):
+       oid = id(obj)
+       _id2obj_dict[oid] = obj
+       return oid
+
+   def id2obj(oid):
+       return _id2obj_dict[oid]
+
diff --git a/Doc/library/webbrowser.rst b/Doc/library/webbrowser.rst
new file mode 100644
index 0000000..c243f7c
--- /dev/null
+++ b/Doc/library/webbrowser.rst
@@ -0,0 +1,199 @@
+
+:mod:`webbrowser` --- Convenient Web-browser controller
+=======================================================
+
+.. module:: webbrowser
+   :synopsis: Easy-to-use controller for Web browsers.
+.. moduleauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+The :mod:`webbrowser` module provides a high-level interface to allow displaying
+Web-based documents to users. Under most circumstances, simply calling the
+:func:`open` function from this module will do the right thing.
+
+Under Unix, graphical browsers are preferred under X11, but text-mode browsers
+will be used if graphical browsers are not available or an X11 display isn't
+available.  If text-mode browsers are used, the calling process will block until
+the user exits the browser.
+
+If the environment variable :envvar:`BROWSER` exists, it is interpreted to
+override the platform default list of browsers, as a os.pathsep-separated list
+of browsers to try in order.  When the value of a list part contains the string
+``%s``, then it is  interpreted as a literal browser command line to be used
+with the argument URL substituted for ``%s``; if the part does not contain
+``%s``, it is simply interpreted as the name of the browser to launch.
+
+For non-Unix platforms, or when a remote browser is available on Unix, the
+controlling process will not wait for the user to finish with the browser, but
+allow the remote browser to maintain its own windows on the display.  If remote
+browsers are not available on Unix, the controlling process will launch a new
+browser and wait.
+
+The script :program:`webbrowser` can be used as a command-line interface for the
+module. It accepts an URL as the argument. It accepts the following optional
+parameters: :option:`-n` opens the URL in a new browser window, if possible;
+:option:`-t` opens the URL in a new browser page ("tab"). The options are,
+naturally, mutually exclusive.
+
+The following exception is defined:
+
+
+.. exception:: Error
+
+   Exception raised when a browser control error occurs.
+
+The following functions are defined:
+
+
+.. function:: open(url[, new=0[, autoraise=1]])
+
+   Display *url* using the default browser. If *new* is 0, the *url* is opened in
+   the same browser window if possible.  If *new* is 1, a new browser window is
+   opened if possible.  If *new* is 2, a new browser page ("tab") is opened if
+   possible.  If *autoraise* is true, the window is raised if possible (note that
+   under many window managers this will occur regardless of the setting of this
+   variable).
+
+   .. versionchanged:: 2.5
+      *new* can now be 2.
+
+
+.. function:: open_new(url)
+
+   Open *url* in a new window of the default browser, if possible, otherwise, open
+   *url* in the only browser window.
+
+
+.. function:: open_new_tab(url)
+
+   Open *url* in a new page ("tab") of the default browser, if possible, otherwise
+   equivalent to :func:`open_new`.
+
+   .. versionadded:: 2.5
+
+
+.. function:: get([name])
+
+   Return a controller object for the browser type *name*.  If *name* is empty,
+   return a controller for a default browser appropriate to the caller's
+   environment.
+
+
+.. function:: register(name, constructor[, instance])
+
+   Register the browser type *name*.  Once a browser type is registered, the
+   :func:`get` function can return a controller for that browser type.  If
+   *instance* is not provided, or is ``None``, *constructor* will be called without
+   parameters to create an instance when needed.  If *instance* is provided,
+   *constructor* will never be called, and may be ``None``.
+
+   This entry point is only useful if you plan to either set the :envvar:`BROWSER`
+   variable or call :func:`get` with a nonempty argument matching the name of a
+   handler you declare.
+
+A number of browser types are predefined.  This table gives the type names that
+may be passed to the :func:`get` function and the corresponding instantiations
+for the controller classes, all defined in this module.
+
++-----------------------+-----------------------------------------+-------+
+| Type Name             | Class Name                              | Notes |
++=======================+=========================================+=======+
+| ``'mozilla'``         | :class:`Mozilla('mozilla')`             |       |
++-----------------------+-----------------------------------------+-------+
+| ``'firefox'``         | :class:`Mozilla('mozilla')`             |       |
++-----------------------+-----------------------------------------+-------+
+| ``'netscape'``        | :class:`Mozilla('netscape')`            |       |
++-----------------------+-----------------------------------------+-------+
+| ``'galeon'``          | :class:`Galeon('galeon')`               |       |
++-----------------------+-----------------------------------------+-------+
+| ``'epiphany'``        | :class:`Galeon('epiphany')`             |       |
++-----------------------+-----------------------------------------+-------+
+| ``'skipstone'``       | :class:`BackgroundBrowser('skipstone')` |       |
++-----------------------+-----------------------------------------+-------+
+| ``'kfmclient'``       | :class:`Konqueror()`                    | \(1)  |
++-----------------------+-----------------------------------------+-------+
+| ``'konqueror'``       | :class:`Konqueror()`                    | \(1)  |
++-----------------------+-----------------------------------------+-------+
+| ``'kfm'``             | :class:`Konqueror()`                    | \(1)  |
++-----------------------+-----------------------------------------+-------+
+| ``'mosaic'``          | :class:`BackgroundBrowser('mosaic')`    |       |
++-----------------------+-----------------------------------------+-------+
+| ``'opera'``           | :class:`Opera()`                        |       |
++-----------------------+-----------------------------------------+-------+
+| ``'grail'``           | :class:`Grail()`                        |       |
++-----------------------+-----------------------------------------+-------+
+| ``'links'``           | :class:`GenericBrowser('links')`        |       |
++-----------------------+-----------------------------------------+-------+
+| ``'elinks'``          | :class:`Elinks('elinks')`               |       |
++-----------------------+-----------------------------------------+-------+
+| ``'lynx'``            | :class:`GenericBrowser('lynx')`         |       |
++-----------------------+-----------------------------------------+-------+
+| ``'w3m'``             | :class:`GenericBrowser('w3m')`          |       |
++-----------------------+-----------------------------------------+-------+
+| ``'windows-default'`` | :class:`WindowsDefault`                 | \(2)  |
++-----------------------+-----------------------------------------+-------+
+| ``'internet-config'`` | :class:`InternetConfig`                 | \(3)  |
++-----------------------+-----------------------------------------+-------+
+| ``'macosx'``          | :class:`MacOSX('default')`              | \(4)  |
++-----------------------+-----------------------------------------+-------+
+
+Notes:
+
+(1)
+   "Konqueror" is the file manager for the KDE desktop environment for Unix, and
+   only makes sense to use if KDE is running.  Some way of reliably detecting KDE
+   would be nice; the :envvar:`KDEDIR` variable is not sufficient.  Note also that
+   the name "kfm" is used even when using the :program:`konqueror` command with KDE
+   2 --- the implementation selects the best strategy for running Konqueror.
+
+(2)
+   Only on Windows platforms.
+
+(3)
+   Only on MacOS platforms; requires the standard MacPython :mod:`ic` module.
+
+(4)
+   Only on MacOS X platform.
+
+Here are some simple examples::
+
+   url = 'http://www.python.org'
+
+   # Open URL in a new tab, if a browser window is already open. 
+   webbrowser.open_new_tab(url + '/doc')
+
+   # Open URL in new window, raising the window if possible.
+   webbrowser.open_new(url)
+
+
+.. _browser-controllers:
+
+Browser Controller Objects
+--------------------------
+
+Browser controllers provide two methods which parallel two of the module-level
+convenience functions:
+
+
+.. method:: controller.open(url[, new[, autoraise=1]])
+
+   Display *url* using the browser handled by this controller. If *new* is 1, a new
+   browser window is opened if possible. If *new* is 2, a new browser page ("tab")
+   is opened if possible.
+
+
+.. method:: controller.open_new(url)
+
+   Open *url* in a new window of the browser handled by this controller, if
+   possible, otherwise, open *url* in the only browser window.  Alias
+   :func:`open_new`.
+
+
+.. method:: controller.open_new_tab(url)
+
+   Open *url* in a new page ("tab") of the browser handled by this controller, if
+   possible, otherwise equivalent to :func:`open_new`.
+
+   .. versionadded:: 2.5
+
diff --git a/Doc/library/whichdb.rst b/Doc/library/whichdb.rst
new file mode 100644
index 0000000..5c69818
--- /dev/null
+++ b/Doc/library/whichdb.rst
@@ -0,0 +1,20 @@
+
+:mod:`whichdb` --- Guess which DBM module created a database
+============================================================
+
+.. module:: whichdb
+   :synopsis: Guess which DBM-style module created a given database.
+
+
+The single function in this module attempts to guess which of the several simple
+database modules available--\ :mod:`dbm`, :mod:`gdbm`, or :mod:`dbhash`\
+--should be used to open a given file.
+
+
+.. function:: whichdb(filename)
+
+   Returns one of the following values: ``None`` if the file can't be opened
+   because it's unreadable or doesn't exist; the empty string (``''``) if the
+   file's format can't be guessed; or a string containing the required module name,
+   such as ``'dbm'`` or ``'gdbm'``.
+
diff --git a/Doc/library/windows.rst b/Doc/library/windows.rst
new file mode 100644
index 0000000..a231bc2
--- /dev/null
+++ b/Doc/library/windows.rst
@@ -0,0 +1,14 @@
+
+****************************
+MS Windows Specific Services
+****************************
+
+This chapter describes modules that are only available on MS Windows platforms.
+
+
+.. toctree::
+
+   msilib.rst
+   msvcrt.rst
+   _winreg.rst
+   winsound.rst
diff --git a/Doc/library/winsound.rst b/Doc/library/winsound.rst
new file mode 100644
index 0000000..c4c04bd
--- /dev/null
+++ b/Doc/library/winsound.rst
@@ -0,0 +1,162 @@
+
+:mod:`winsound` --- Sound-playing interface for Windows
+=======================================================
+
+.. module:: winsound
+   :platform: Windows
+   :synopsis: Access to the sound-playing machinery for Windows.
+.. moduleauthor:: Toby Dickenson <htrd90@zepler.org>
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+
+
+.. versionadded:: 1.5.2
+
+The :mod:`winsound` module provides access to the basic sound-playing machinery
+provided by Windows platforms.  It includes functions and several constants.
+
+
+.. function:: Beep(frequency, duration)
+
+   Beep the PC's speaker. The *frequency* parameter specifies frequency, in hertz,
+   of the sound, and must be in the range 37 through 32,767. The *duration*
+   parameter specifies the number of milliseconds the sound should last.  If the
+   system is not able to beep the speaker, :exc:`RuntimeError` is raised.
+
+   .. note::
+
+      Under Windows 95 and 98, the Windows :cfunc:`Beep` function exists but is
+      useless (it ignores its arguments).  In that case Python simulates it via direct
+      port manipulation (added in version 2.1).  It's unknown whether that will work
+      on all systems.
+
+   .. versionadded:: 1.6
+
+
+.. function:: PlaySound(sound, flags)
+
+   Call the underlying :cfunc:`PlaySound` function from the Platform API.  The
+   *sound* parameter may be a filename, audio data as a string, or ``None``.  Its
+   interpretation depends on the value of *flags*, which can be a bit-wise ORed
+   combination of the constants described below.  If the system indicates an error,
+   :exc:`RuntimeError` is raised.
+
+
+.. function:: MessageBeep([type=MB_OK])
+
+   Call the underlying :cfunc:`MessageBeep` function from the Platform API.  This
+   plays a sound as specified in the registry.  The *type* argument specifies which
+   sound to play; possible values are ``-1``, ``MB_ICONASTERISK``,
+   ``MB_ICONEXCLAMATION``, ``MB_ICONHAND``, ``MB_ICONQUESTION``, and ``MB_OK``, all
+   described below.  The value ``-1`` produces a "simple beep"; this is the final
+   fallback if a sound cannot be played otherwise.
+
+   .. versionadded:: 2.3
+
+
+.. data:: SND_FILENAME
+
+   The *sound* parameter is the name of a WAV file. Do not use with
+   :const:`SND_ALIAS`.
+
+
+.. data:: SND_ALIAS
+
+   The *sound* parameter is a sound association name from the registry.  If the
+   registry contains no such name, play the system default sound unless
+   :const:`SND_NODEFAULT` is also specified. If no default sound is registered,
+   raise :exc:`RuntimeError`. Do not use with :const:`SND_FILENAME`.
+
+   All Win32 systems support at least the following; most systems support many
+   more:
+
+   +--------------------------+----------------------------------------+
+   | :func:`PlaySound` *name* | Corresponding Control Panel Sound name |
+   +==========================+========================================+
+   | ``'SystemAsterisk'``     | Asterisk                               |
+   +--------------------------+----------------------------------------+
+   | ``'SystemExclamation'``  | Exclamation                            |
+   +--------------------------+----------------------------------------+
+   | ``'SystemExit'``         | Exit Windows                           |
+   +--------------------------+----------------------------------------+
+   | ``'SystemHand'``         | Critical Stop                          |
+   +--------------------------+----------------------------------------+
+   | ``'SystemQuestion'``     | Question                               |
+   +--------------------------+----------------------------------------+
+
+   For example::
+
+      import winsound
+      # Play Windows exit sound.
+      winsound.PlaySound("SystemExit", winsound.SND_ALIAS)
+
+      # Probably play Windows default sound, if any is registered (because
+      # "*" probably isn't the registered name of any sound).
+      winsound.PlaySound("*", winsound.SND_ALIAS)
+
+
+.. data:: SND_LOOP
+
+   Play the sound repeatedly.  The :const:`SND_ASYNC` flag must also be used to
+   avoid blocking.  Cannot be used with :const:`SND_MEMORY`.
+
+
+.. data:: SND_MEMORY
+
+   The *sound* parameter to :func:`PlaySound` is a memory image of a WAV file, as a
+   string.
+
+   .. note::
+
+      This module does not support playing from a memory image asynchronously, so a
+      combination of this flag and :const:`SND_ASYNC` will raise :exc:`RuntimeError`.
+
+
+.. data:: SND_PURGE
+
+   Stop playing all instances of the specified sound.
+
+
+.. data:: SND_ASYNC
+
+   Return immediately, allowing sounds to play asynchronously.
+
+
+.. data:: SND_NODEFAULT
+
+   If the specified sound cannot be found, do not play the system default sound.
+
+
+.. data:: SND_NOSTOP
+
+   Do not interrupt sounds currently playing.
+
+
+.. data:: SND_NOWAIT
+
+   Return immediately if the sound driver is busy.
+
+
+.. data:: MB_ICONASTERISK
+
+   Play the ``SystemDefault`` sound.
+
+
+.. data:: MB_ICONEXCLAMATION
+
+   Play the ``SystemExclamation`` sound.
+
+
+.. data:: MB_ICONHAND
+
+   Play the ``SystemHand`` sound.
+
+
+.. data:: MB_ICONQUESTION
+
+   Play the ``SystemQuestion`` sound.
+
+
+.. data:: MB_OK
+
+   Play the ``SystemDefault`` sound.
+
diff --git a/Doc/library/wsgiref.rst b/Doc/library/wsgiref.rst
new file mode 100644
index 0000000..ff68684
--- /dev/null
+++ b/Doc/library/wsgiref.rst
@@ -0,0 +1,641 @@
+:mod:`wsgiref` --- WSGI Utilities and Reference Implementation
+==============================================================
+
+.. module:: wsgiref
+   :synopsis: WSGI Utilities and Reference Implementation.
+.. moduleauthor:: Phillip J. Eby <pje@telecommunity.com>
+.. sectionauthor:: Phillip J. Eby <pje@telecommunity.com>
+
+
+.. versionadded:: 2.5
+
+The Web Server Gateway Interface (WSGI) is a standard interface between web
+server software and web applications written in Python. Having a standard
+interface makes it easy to use an application that supports WSGI with a number
+of different web servers.
+
+Only authors of web servers and programming frameworks need to know every detail
+and corner case of the WSGI design.  You don't need to understand every detail
+of WSGI just to install a WSGI application or to write a web application using
+an existing framework.
+
+:mod:`wsgiref` is a reference implementation of the WSGI specification that can
+be used to add WSGI support to a web server or framework.  It provides utilities
+for manipulating WSGI environment variables and response headers, base classes
+for implementing WSGI servers, a demo HTTP server that serves WSGI applications,
+and a validation tool that checks WSGI servers and applications for conformance
+to the WSGI specification (:pep:`333`).
+
+See http://www.wsgi.org for more information about WSGI, and links to tutorials
+and other resources.
+
+.. % XXX If you're just trying to write a web application...
+
+
+:mod:`wsgiref.util` -- WSGI environment utilities
+-------------------------------------------------
+
+.. module:: wsgiref.util
+   :synopsis: WSGI environment utilities.
+
+
+This module provides a variety of utility functions for working with WSGI
+environments.  A WSGI environment is a dictionary containing HTTP request
+variables as described in :pep:`333`.  All of the functions taking an *environ*
+parameter expect a WSGI-compliant dictionary to be supplied; please see
+:pep:`333` for a detailed specification.
+
+
+.. function:: guess_scheme(environ)
+
+   Return a guess for whether ``wsgi.url_scheme`` should be "http" or "https", by
+   checking for a ``HTTPS`` environment variable in the *environ* dictionary.  The
+   return value is a string.
+
+   This function is useful when creating a gateway that wraps CGI or a CGI-like
+   protocol such as FastCGI.  Typically, servers providing such protocols will
+   include a ``HTTPS`` variable with a value of "1" "yes", or "on" when a request
+   is received via SSL.  So, this function returns "https" if such a value is
+   found, and "http" otherwise.
+
+
+.. function:: request_uri(environ [, include_query=1])
+
+   Return the full request URI, optionally including the query string, using the
+   algorithm found in the "URL Reconstruction" section of :pep:`333`.  If
+   *include_query* is false, the query string is not included in the resulting URI.
+
+
+.. function:: application_uri(environ)
+
+   Similar to :func:`request_uri`, except that the ``PATH_INFO`` and
+   ``QUERY_STRING`` variables are ignored.  The result is the base URI of the
+   application object addressed by the request.
+
+
+.. function:: shift_path_info(environ)
+
+   Shift a single name from ``PATH_INFO`` to ``SCRIPT_NAME`` and return the name.
+   The *environ* dictionary is *modified* in-place; use a copy if you need to keep
+   the original ``PATH_INFO`` or ``SCRIPT_NAME`` intact.
+
+   If there are no remaining path segments in ``PATH_INFO``, ``None`` is returned.
+
+   Typically, this routine is used to process each portion of a request URI path,
+   for example to treat the path as a series of dictionary keys. This routine
+   modifies the passed-in environment to make it suitable for invoking another WSGI
+   application that is located at the target URI. For example, if there is a WSGI
+   application at ``/foo``, and the request URI path is ``/foo/bar/baz``, and the
+   WSGI application at ``/foo`` calls :func:`shift_path_info`, it will receive the
+   string "bar", and the environment will be updated to be suitable for passing to
+   a WSGI application at ``/foo/bar``.  That is, ``SCRIPT_NAME`` will change from
+   ``/foo`` to ``/foo/bar``, and ``PATH_INFO`` will change from ``/bar/baz`` to
+   ``/baz``.
+
+   When ``PATH_INFO`` is just a "/", this routine returns an empty string and
+   appends a trailing slash to ``SCRIPT_NAME``, even though empty path segments are
+   normally ignored, and ``SCRIPT_NAME`` doesn't normally end in a slash.  This is
+   intentional behavior, to ensure that an application can tell the difference
+   between URIs ending in ``/x`` from ones ending in ``/x/`` when using this
+   routine to do object traversal.
+
+
+.. function:: setup_testing_defaults(environ)
+
+   Update *environ* with trivial defaults for testing purposes.
+
+   This routine adds various parameters required for WSGI, including ``HTTP_HOST``,
+   ``SERVER_NAME``, ``SERVER_PORT``, ``REQUEST_METHOD``, ``SCRIPT_NAME``,
+   ``PATH_INFO``, and all of the :pep:`333`\ -defined ``wsgi.*`` variables.  It
+   only supplies default values, and does not replace any existing settings for
+   these variables.
+
+   This routine is intended to make it easier for unit tests of WSGI servers and
+   applications to set up dummy environments.  It should NOT be used by actual WSGI
+   servers or applications, since the data is fake!
+
+In addition to the environment functions above, the :mod:`wsgiref.util` module
+also provides these miscellaneous utilities:
+
+
+.. function:: is_hop_by_hop(header_name)
+
+   Return true if 'header_name' is an HTTP/1.1 "Hop-by-Hop" header, as defined by
+   :rfc:`2616`.
+
+
+.. class:: FileWrapper(filelike [, blksize=8192])
+
+   A wrapper to convert a file-like object to an iterator.  The resulting objects
+   support both :meth:`__getitem__` and :meth:`__iter__` iteration styles, for
+   compatibility with Python 2.1 and Jython. As the object is iterated over, the
+   optional *blksize* parameter will be repeatedly passed to the *filelike*
+   object's :meth:`read` method to obtain strings to yield.  When :meth:`read`
+   returns an empty string, iteration is ended and is not resumable.
+
+   If *filelike* has a :meth:`close` method, the returned object will also have a
+   :meth:`close` method, and it will invoke the *filelike* object's :meth:`close`
+   method when called.
+
+
+:mod:`wsgiref.headers` -- WSGI response header tools
+----------------------------------------------------
+
+.. module:: wsgiref.headers
+   :synopsis: WSGI response header tools.
+
+
+This module provides a single class, :class:`Headers`, for convenient
+manipulation of WSGI response headers using a mapping-like interface.
+
+
+.. class:: Headers(headers)
+
+   Create a mapping-like object wrapping *headers*, which must be a list of header
+   name/value tuples as described in :pep:`333`.  Any changes made to the new
+   :class:`Headers` object will directly update the *headers* list it was created
+   with.
+
+   :class:`Headers` objects support typical mapping operations including
+   :meth:`__getitem__`, :meth:`get`, :meth:`__setitem__`, :meth:`setdefault`,
+   :meth:`__delitem__`, :meth:`__contains__` and :meth:`has_key`.  For each of
+   these methods, the key is the header name (treated case-insensitively), and the
+   value is the first value associated with that header name.  Setting a header
+   deletes any existing values for that header, then adds a new value at the end of
+   the wrapped header list.  Headers' existing order is generally maintained, with
+   new headers added to the end of the wrapped list.
+
+   Unlike a dictionary, :class:`Headers` objects do not raise an error when you try
+   to get or delete a key that isn't in the wrapped header list. Getting a
+   nonexistent header just returns ``None``, and deleting a nonexistent header does
+   nothing.
+
+   :class:`Headers` objects also support :meth:`keys`, :meth:`values`, and
+   :meth:`items` methods.  The lists returned by :meth:`keys` and :meth:`items` can
+   include the same key more than once if there is a multi-valued header.  The
+   ``len()`` of a :class:`Headers` object is the same as the length of its
+   :meth:`items`, which is the same as the length of the wrapped header list.  In
+   fact, the :meth:`items` method just returns a copy of the wrapped header list.
+
+   Calling ``str()`` on a :class:`Headers` object returns a formatted string
+   suitable for transmission as HTTP response headers.  Each header is placed on a
+   line with its value, separated by a colon and a space. Each line is terminated
+   by a carriage return and line feed, and the string is terminated with a blank
+   line.
+
+   In addition to their mapping interface and formatting features, :class:`Headers`
+   objects also have the following methods for querying and adding multi-valued
+   headers, and for adding headers with MIME parameters:
+
+
+   .. method:: Headers.get_all(name)
+
+      Return a list of all the values for the named header.
+
+      The returned list will be sorted in the order they appeared in the original
+      header list or were added to this instance, and may contain duplicates.  Any
+      fields deleted and re-inserted are always appended to the header list.  If no
+      fields exist with the given name, returns an empty list.
+
+
+   .. method:: Headers.add_header(name, value, **_params)
+
+      Add a (possibly multi-valued) header, with optional MIME parameters specified
+      via keyword arguments.
+
+      *name* is the header field to add.  Keyword arguments can be used to set MIME
+      parameters for the header field.  Each parameter must be a string or ``None``.
+      Underscores in parameter names are converted to dashes, since dashes are illegal
+      in Python identifiers, but many MIME parameter names include dashes.  If the
+      parameter value is a string, it is added to the header value parameters in the
+      form ``name="value"``. If it is ``None``, only the parameter name is added.
+      (This is used for MIME parameters without a value.)  Example usage::
+
+         h.add_header('content-disposition', 'attachment', filename='bud.gif')
+
+      The above will add a header that looks like this::
+
+         Content-Disposition: attachment; filename="bud.gif"
+
+
+:mod:`wsgiref.simple_server` -- a simple WSGI HTTP server
+---------------------------------------------------------
+
+.. module:: wsgiref.simple_server
+   :synopsis: A simple WSGI HTTP server.
+
+
+This module implements a simple HTTP server (based on :mod:`BaseHTTPServer`)
+that serves WSGI applications.  Each server instance serves a single WSGI
+application on a given host and port.  If you want to serve multiple
+applications on a single host and port, you should create a WSGI application
+that parses ``PATH_INFO`` to select which application to invoke for each
+request.  (E.g., using the :func:`shift_path_info` function from
+:mod:`wsgiref.util`.)
+
+
+.. function:: make_server(host, port, app [, server_class=WSGIServer [, handler_class=WSGIRequestHandler]])
+
+   Create a new WSGI server listening on *host* and *port*, accepting connections
+   for *app*.  The return value is an instance of the supplied *server_class*, and
+   will process requests using the specified *handler_class*.  *app* must be a WSGI
+   application object, as defined by :pep:`333`.
+
+   Example usage::
+
+      from wsgiref.simple_server import make_server, demo_app
+
+      httpd = make_server('', 8000, demo_app)
+      print "Serving HTTP on port 8000..."
+
+      # Respond to requests until process is killed
+      httpd.serve_forever()
+
+      # Alternative: serve one request, then exit
+      ##httpd.handle_request()
+
+
+.. function:: demo_app(environ, start_response)
+
+   This function is a small but complete WSGI application that returns a text page
+   containing the message "Hello world!" and a list of the key/value pairs provided
+   in the *environ* parameter.  It's useful for verifying that a WSGI server (such
+   as :mod:`wsgiref.simple_server`) is able to run a simple WSGI application
+   correctly.
+
+
+.. class:: WSGIServer(server_address, RequestHandlerClass)
+
+   Create a :class:`WSGIServer` instance.  *server_address* should be a
+   ``(host,port)`` tuple, and *RequestHandlerClass* should be the subclass of
+   :class:`BaseHTTPServer.BaseHTTPRequestHandler` that will be used to process
+   requests.
+
+   You do not normally need to call this constructor, as the :func:`make_server`
+   function can handle all the details for you.
+
+   :class:`WSGIServer` is a subclass of :class:`BaseHTTPServer.HTTPServer`, so all
+   of its methods (such as :meth:`serve_forever` and :meth:`handle_request`) are
+   available. :class:`WSGIServer` also provides these WSGI-specific methods:
+
+
+   .. method:: WSGIServer.set_app(application)
+
+      Sets the callable *application* as the WSGI application that will receive
+      requests.
+
+
+   .. method:: WSGIServer.get_app()
+
+      Returns the currently-set application callable.
+
+   Normally, however, you do not need to use these additional methods, as
+   :meth:`set_app` is normally called by :func:`make_server`, and the
+   :meth:`get_app` exists mainly for the benefit of request handler instances.
+
+
+.. class:: WSGIRequestHandler(request, client_address, server)
+
+   Create an HTTP handler for the given *request* (i.e. a socket), *client_address*
+   (a ``(host,port)`` tuple), and *server* (:class:`WSGIServer` instance).
+
+   You do not need to create instances of this class directly; they are
+   automatically created as needed by :class:`WSGIServer` objects.  You can,
+   however, subclass this class and supply it as a *handler_class* to the
+   :func:`make_server` function.  Some possibly relevant methods for overriding in
+   subclasses:
+
+
+   .. method:: WSGIRequestHandler.get_environ()
+
+      Returns a dictionary containing the WSGI environment for a request.  The default
+      implementation copies the contents of the :class:`WSGIServer` object's
+      :attr:`base_environ` dictionary attribute and then adds various headers derived
+      from the HTTP request.  Each call to this method should return a new dictionary
+      containing all of the relevant CGI environment variables as specified in
+      :pep:`333`.
+
+
+   .. method:: WSGIRequestHandler.get_stderr()
+
+      Return the object that should be used as the ``wsgi.errors`` stream. The default
+      implementation just returns ``sys.stderr``.
+
+
+   .. method:: WSGIRequestHandler.handle()
+
+      Process the HTTP request.  The default implementation creates a handler instance
+      using a :mod:`wsgiref.handlers` class to implement the actual WSGI application
+      interface.
+
+
+:mod:`wsgiref.validate` --- WSGI conformance checker
+----------------------------------------------------
+
+.. module:: wsgiref.validate
+   :synopsis: WSGI conformance checker.
+
+
+When creating new WSGI application objects, frameworks, servers, or middleware,
+it can be useful to validate the new code's conformance using
+:mod:`wsgiref.validate`.  This module provides a function that creates WSGI
+application objects that validate communications between a WSGI server or
+gateway and a WSGI application object, to check both sides for protocol
+conformance.
+
+Note that this utility does not guarantee complete :pep:`333` compliance; an
+absence of errors from this module does not necessarily mean that errors do not
+exist.  However, if this module does produce an error, then it is virtually
+certain that either the server or application is not 100% compliant.
+
+This module is based on the :mod:`paste.lint` module from Ian Bicking's "Python
+Paste" library.
+
+
+.. function:: validator(application)
+
+   Wrap *application* and return a new WSGI application object.  The returned
+   application will forward all requests to the original *application*, and will
+   check that both the *application* and the server invoking it are conforming to
+   the WSGI specification and to RFC 2616.
+
+   Any detected nonconformance results in an :exc:`AssertionError` being raised;
+   note, however, that how these errors are handled is server-dependent.  For
+   example, :mod:`wsgiref.simple_server` and other servers based on
+   :mod:`wsgiref.handlers` (that don't override the error handling methods to do
+   something else) will simply output a message that an error has occurred, and
+   dump the traceback to ``sys.stderr`` or some other error stream.
+
+   This wrapper may also generate output using the :mod:`warnings` module to
+   indicate behaviors that are questionable but which may not actually be
+   prohibited by :pep:`333`.  Unless they are suppressed using Python command-line
+   options or the :mod:`warnings` API, any such warnings will be written to
+   ``sys.stderr`` (*not* ``wsgi.errors``, unless they happen to be the same
+   object).
+
+
+:mod:`wsgiref.handlers` -- server/gateway base classes
+------------------------------------------------------
+
+.. module:: wsgiref.handlers
+   :synopsis: WSGI server/gateway base classes.
+
+
+This module provides base handler classes for implementing WSGI servers and
+gateways.  These base classes handle most of the work of communicating with a
+WSGI application, as long as they are given a CGI-like environment, along with
+input, output, and error streams.
+
+
+.. class:: CGIHandler()
+
+   CGI-based invocation via ``sys.stdin``, ``sys.stdout``, ``sys.stderr`` and
+   ``os.environ``.  This is useful when you have a WSGI application and want to run
+   it as a CGI script.  Simply invoke ``CGIHandler().run(app)``, where ``app`` is
+   the WSGI application object you wish to invoke.
+
+   This class is a subclass of :class:`BaseCGIHandler` that sets ``wsgi.run_once``
+   to true, ``wsgi.multithread`` to false, and ``wsgi.multiprocess`` to true, and
+   always uses :mod:`sys` and :mod:`os` to obtain the necessary CGI streams and
+   environment.
+
+
+.. class:: BaseCGIHandler(stdin, stdout, stderr, environ [, multithread=True [, multiprocess=False]])
+
+   Similar to :class:`CGIHandler`, but instead of using the :mod:`sys` and
+   :mod:`os` modules, the CGI environment and I/O streams are specified explicitly.
+   The *multithread* and *multiprocess* values are used to set the
+   ``wsgi.multithread`` and ``wsgi.multiprocess`` flags for any applications run by
+   the handler instance.
+
+   This class is a subclass of :class:`SimpleHandler` intended for use with
+   software other than HTTP "origin servers".  If you are writing a gateway
+   protocol implementation (such as CGI, FastCGI, SCGI, etc.) that uses a
+   ``Status:`` header to send an HTTP status, you probably want to subclass this
+   instead of :class:`SimpleHandler`.
+
+
+.. class:: SimpleHandler(stdin, stdout, stderr, environ [,multithread=True [, multiprocess=False]])
+
+   Similar to :class:`BaseCGIHandler`, but designed for use with HTTP origin
+   servers.  If you are writing an HTTP server implementation, you will probably
+   want to subclass this instead of :class:`BaseCGIHandler`
+
+   This class is a subclass of :class:`BaseHandler`.  It overrides the
+   :meth:`__init__`, :meth:`get_stdin`, :meth:`get_stderr`, :meth:`add_cgi_vars`,
+   :meth:`_write`, and :meth:`_flush` methods to support explicitly setting the
+   environment and streams via the constructor.  The supplied environment and
+   streams are stored in the :attr:`stdin`, :attr:`stdout`, :attr:`stderr`, and
+   :attr:`environ` attributes.
+
+
+.. class:: BaseHandler()
+
+   This is an abstract base class for running WSGI applications.  Each instance
+   will handle a single HTTP request, although in principle you could create a
+   subclass that was reusable for multiple requests.
+
+   :class:`BaseHandler` instances have only one method intended for external use:
+
+
+   .. method:: BaseHandler.run(app)
+
+      Run the specified WSGI application, *app*.
+
+   All of the other :class:`BaseHandler` methods are invoked by this method in the
+   process of running the application, and thus exist primarily to allow
+   customizing the process.
+
+   The following methods MUST be overridden in a subclass:
+
+
+   .. method:: BaseHandler._write(data)
+
+      Buffer the string *data* for transmission to the client.  It's okay if this
+      method actually transmits the data; :class:`BaseHandler` just separates write
+      and flush operations for greater efficiency when the underlying system actually
+      has such a distinction.
+
+
+   .. method:: BaseHandler._flush()
+
+      Force buffered data to be transmitted to the client.  It's okay if this method
+      is a no-op (i.e., if :meth:`_write` actually sends the data).
+
+
+   .. method:: BaseHandler.get_stdin()
+
+      Return an input stream object suitable for use as the ``wsgi.input`` of the
+      request currently being processed.
+
+
+   .. method:: BaseHandler.get_stderr()
+
+      Return an output stream object suitable for use as the ``wsgi.errors`` of the
+      request currently being processed.
+
+
+   .. method:: BaseHandler.add_cgi_vars()
+
+      Insert CGI variables for the current request into the :attr:`environ` attribute.
+
+   Here are some other methods and attributes you may wish to override. This list
+   is only a summary, however, and does not include every method that can be
+   overridden.  You should consult the docstrings and source code for additional
+   information before attempting to create a customized :class:`BaseHandler`
+   subclass.
+
+   Attributes and methods for customizing the WSGI environment:
+
+
+   .. attribute:: BaseHandler.wsgi_multithread
+
+      The value to be used for the ``wsgi.multithread`` environment variable.  It
+      defaults to true in :class:`BaseHandler`, but may have a different default (or
+      be set by the constructor) in the other subclasses.
+
+
+   .. attribute:: BaseHandler.wsgi_multiprocess
+
+      The value to be used for the ``wsgi.multiprocess`` environment variable.  It
+      defaults to true in :class:`BaseHandler`, but may have a different default (or
+      be set by the constructor) in the other subclasses.
+
+
+   .. attribute:: BaseHandler.wsgi_run_once
+
+      The value to be used for the ``wsgi.run_once`` environment variable.  It
+      defaults to false in :class:`BaseHandler`, but :class:`CGIHandler` sets it to
+      true by default.
+
+
+   .. attribute:: BaseHandler.os_environ
+
+      The default environment variables to be included in every request's WSGI
+      environment.  By default, this is a copy of ``os.environ`` at the time that
+      :mod:`wsgiref.handlers` was imported, but subclasses can either create their own
+      at the class or instance level.  Note that the dictionary should be considered
+      read-only, since the default value is shared between multiple classes and
+      instances.
+
+
+   .. attribute:: BaseHandler.server_software
+
+      If the :attr:`origin_server` attribute is set, this attribute's value is used to
+      set the default ``SERVER_SOFTWARE`` WSGI environment variable, and also to set a
+      default ``Server:`` header in HTTP responses.  It is ignored for handlers (such
+      as :class:`BaseCGIHandler` and :class:`CGIHandler`) that are not HTTP origin
+      servers.
+
+
+   .. method:: BaseHandler.get_scheme()
+
+      Return the URL scheme being used for the current request.  The default
+      implementation uses the :func:`guess_scheme` function from :mod:`wsgiref.util`
+      to guess whether the scheme should be "http" or "https", based on the current
+      request's :attr:`environ` variables.
+
+
+   .. method:: BaseHandler.setup_environ()
+
+      Set the :attr:`environ` attribute to a fully-populated WSGI environment.  The
+      default implementation uses all of the above methods and attributes, plus the
+      :meth:`get_stdin`, :meth:`get_stderr`, and :meth:`add_cgi_vars` methods and the
+      :attr:`wsgi_file_wrapper` attribute.  It also inserts a ``SERVER_SOFTWARE`` key
+      if not present, as long as the :attr:`origin_server` attribute is a true value
+      and the :attr:`server_software` attribute is set.
+
+   Methods and attributes for customizing exception handling:
+
+
+   .. method:: BaseHandler.log_exception(exc_info)
+
+      Log the *exc_info* tuple in the server log.  *exc_info* is a ``(type, value,
+      traceback)`` tuple.  The default implementation simply writes the traceback to
+      the request's ``wsgi.errors`` stream and flushes it.  Subclasses can override
+      this method to change the format or retarget the output, mail the traceback to
+      an administrator, or whatever other action may be deemed suitable.
+
+
+   .. attribute:: BaseHandler.traceback_limit
+
+      The maximum number of frames to include in tracebacks output by the default
+      :meth:`log_exception` method.  If ``None``, all frames are included.
+
+
+   .. method:: BaseHandler.error_output(environ, start_response)
+
+      This method is a WSGI application to generate an error page for the user.  It is
+      only invoked if an error occurs before headers are sent to the client.
+
+      This method can access the current error information using ``sys.exc_info()``,
+      and should pass that information to *start_response* when calling it (as
+      described in the "Error Handling" section of :pep:`333`).
+
+      The default implementation just uses the :attr:`error_status`,
+      :attr:`error_headers`, and :attr:`error_body` attributes to generate an output
+      page.  Subclasses can override this to produce more dynamic error output.
+
+      Note, however, that it's not recommended from a security perspective to spit out
+      diagnostics to any old user; ideally, you should have to do something special to
+      enable diagnostic output, which is why the default implementation doesn't
+      include any.
+
+
+   .. attribute:: BaseHandler.error_status
+
+      The HTTP status used for error responses.  This should be a status string as
+      defined in :pep:`333`; it defaults to a 500 code and message.
+
+
+   .. attribute:: BaseHandler.error_headers
+
+      The HTTP headers used for error responses.  This should be a list of WSGI
+      response headers (``(name, value)`` tuples), as described in :pep:`333`.  The
+      default list just sets the content type to ``text/plain``.
+
+
+   .. attribute:: BaseHandler.error_body
+
+      The error response body.  This should be an HTTP response body string. It
+      defaults to the plain text, "A server error occurred.  Please contact the
+      administrator."
+
+   Methods and attributes for :pep:`333`'s "Optional Platform-Specific File
+   Handling" feature:
+
+
+   .. attribute:: BaseHandler.wsgi_file_wrapper
+
+      A ``wsgi.file_wrapper`` factory, or ``None``.  The default value of this
+      attribute is the :class:`FileWrapper` class from :mod:`wsgiref.util`.
+
+
+   .. method:: BaseHandler.sendfile()
+
+      Override to implement platform-specific file transmission.  This method is
+      called only if the application's return value is an instance of the class
+      specified by the :attr:`wsgi_file_wrapper` attribute.  It should return a true
+      value if it was able to successfully transmit the file, so that the default
+      transmission code will not be executed. The default implementation of this
+      method just returns a false value.
+
+   Miscellaneous methods and attributes:
+
+
+   .. attribute:: BaseHandler.origin_server
+
+      This attribute should be set to a true value if the handler's :meth:`_write` and
+      :meth:`_flush` are being used to communicate directly to the client, rather than
+      via a CGI-like gateway protocol that wants the HTTP status in a special
+      ``Status:`` header.
+
+      This attribute's default value is true in :class:`BaseHandler`, but false in
+      :class:`BaseCGIHandler` and :class:`CGIHandler`.
+
+
+   .. attribute:: BaseHandler.http_version
+
+      If :attr:`origin_server` is true, this string attribute is used to set the HTTP
+      version of the response set to the client.  It defaults to ``"1.0"``.
+
diff --git a/Doc/library/xdrlib.rst b/Doc/library/xdrlib.rst
new file mode 100644
index 0000000..6339a7f
--- /dev/null
+++ b/Doc/library/xdrlib.rst
@@ -0,0 +1,276 @@
+
+:mod:`xdrlib` --- Encode and decode XDR data
+============================================
+
+.. module:: xdrlib
+   :synopsis: Encoders and decoders for the External Data Representation (XDR).
+
+
+.. index::
+   single: XDR
+   single: External Data Representation
+
+The :mod:`xdrlib` module supports the External Data Representation Standard as
+described in :rfc:`1014`, written by Sun Microsystems, Inc. June 1987.  It
+supports most of the data types described in the RFC.
+
+The :mod:`xdrlib` module defines two classes, one for packing variables into XDR
+representation, and another for unpacking from XDR representation.  There are
+also two exception classes.
+
+
+.. class:: Packer()
+
+   :class:`Packer` is the class for packing data into XDR representation. The
+   :class:`Packer` class is instantiated with no arguments.
+
+
+.. class:: Unpacker(data)
+
+   ``Unpacker`` is the complementary class which unpacks XDR data values from a
+   string buffer.  The input buffer is given as *data*.
+
+
+.. seealso::
+
+   :rfc:`1014` - XDR: External Data Representation Standard
+      This RFC defined the encoding of data which was XDR at the time this module was
+      originally written.  It has apparently been obsoleted by :rfc:`1832`.
+
+   :rfc:`1832` - XDR: External Data Representation Standard
+      Newer RFC that provides a revised definition of XDR.
+
+
+.. _xdr-packer-objects:
+
+Packer Objects
+--------------
+
+:class:`Packer` instances have the following methods:
+
+
+.. method:: Packer.get_buffer()
+
+   Returns the current pack buffer as a string.
+
+
+.. method:: Packer.reset()
+
+   Resets the pack buffer to the empty string.
+
+In general, you can pack any of the most common XDR data types by calling the
+appropriate ``pack_type()`` method.  Each method takes a single argument, the
+value to pack.  The following simple data type packing methods are supported:
+:meth:`pack_uint`, :meth:`pack_int`, :meth:`pack_enum`, :meth:`pack_bool`,
+:meth:`pack_uhyper`, and :meth:`pack_hyper`.
+
+
+.. method:: Packer.pack_float(value)
+
+   Packs the single-precision floating point number *value*.
+
+
+.. method:: Packer.pack_double(value)
+
+   Packs the double-precision floating point number *value*.
+
+The following methods support packing strings, bytes, and opaque data:
+
+
+.. method:: Packer.pack_fstring(n, s)
+
+   Packs a fixed length string, *s*.  *n* is the length of the string but it is
+   *not* packed into the data buffer.  The string is padded with null bytes if
+   necessary to guaranteed 4 byte alignment.
+
+
+.. method:: Packer.pack_fopaque(n, data)
+
+   Packs a fixed length opaque data stream, similarly to :meth:`pack_fstring`.
+
+
+.. method:: Packer.pack_string(s)
+
+   Packs a variable length string, *s*.  The length of the string is first packed
+   as an unsigned integer, then the string data is packed with
+   :meth:`pack_fstring`.
+
+
+.. method:: Packer.pack_opaque(data)
+
+   Packs a variable length opaque data string, similarly to :meth:`pack_string`.
+
+
+.. method:: Packer.pack_bytes(bytes)
+
+   Packs a variable length byte stream, similarly to :meth:`pack_string`.
+
+The following methods support packing arrays and lists:
+
+
+.. method:: Packer.pack_list(list, pack_item)
+
+   Packs a *list* of homogeneous items.  This method is useful for lists with an
+   indeterminate size; i.e. the size is not available until the entire list has
+   been walked.  For each item in the list, an unsigned integer ``1`` is packed
+   first, followed by the data value from the list.  *pack_item* is the function
+   that is called to pack the individual item.  At the end of the list, an unsigned
+   integer ``0`` is packed.
+
+   For example, to pack a list of integers, the code might appear like this::
+
+      import xdrlib
+      p = xdrlib.Packer()
+      p.pack_list([1, 2, 3], p.pack_int)
+
+
+.. method:: Packer.pack_farray(n, array, pack_item)
+
+   Packs a fixed length list (*array*) of homogeneous items.  *n* is the length of
+   the list; it is *not* packed into the buffer, but a :exc:`ValueError` exception
+   is raised if ``len(array)`` is not equal to *n*.  As above, *pack_item* is the
+   function used to pack each element.
+
+
+.. method:: Packer.pack_array(list, pack_item)
+
+   Packs a variable length *list* of homogeneous items.  First, the length of the
+   list is packed as an unsigned integer, then each element is packed as in
+   :meth:`pack_farray` above.
+
+
+.. _xdr-unpacker-objects:
+
+Unpacker Objects
+----------------
+
+The :class:`Unpacker` class offers the following methods:
+
+
+.. method:: Unpacker.reset(data)
+
+   Resets the string buffer with the given *data*.
+
+
+.. method:: Unpacker.get_position()
+
+   Returns the current unpack position in the data buffer.
+
+
+.. method:: Unpacker.set_position(position)
+
+   Sets the data buffer unpack position to *position*.  You should be careful about
+   using :meth:`get_position` and :meth:`set_position`.
+
+
+.. method:: Unpacker.get_buffer()
+
+   Returns the current unpack data buffer as a string.
+
+
+.. method:: Unpacker.done()
+
+   Indicates unpack completion.  Raises an :exc:`Error` exception if all of the
+   data has not been unpacked.
+
+In addition, every data type that can be packed with a :class:`Packer`, can be
+unpacked with an :class:`Unpacker`.  Unpacking methods are of the form
+``unpack_type()``, and take no arguments.  They return the unpacked object.
+
+
+.. method:: Unpacker.unpack_float()
+
+   Unpacks a single-precision floating point number.
+
+
+.. method:: Unpacker.unpack_double()
+
+   Unpacks a double-precision floating point number, similarly to
+   :meth:`unpack_float`.
+
+In addition, the following methods unpack strings, bytes, and opaque data:
+
+
+.. method:: Unpacker.unpack_fstring(n)
+
+   Unpacks and returns a fixed length string.  *n* is the number of characters
+   expected.  Padding with null bytes to guaranteed 4 byte alignment is assumed.
+
+
+.. method:: Unpacker.unpack_fopaque(n)
+
+   Unpacks and returns a fixed length opaque data stream, similarly to
+   :meth:`unpack_fstring`.
+
+
+.. method:: Unpacker.unpack_string()
+
+   Unpacks and returns a variable length string.  The length of the string is first
+   unpacked as an unsigned integer, then the string data is unpacked with
+   :meth:`unpack_fstring`.
+
+
+.. method:: Unpacker.unpack_opaque()
+
+   Unpacks and returns a variable length opaque data string, similarly to
+   :meth:`unpack_string`.
+
+
+.. method:: Unpacker.unpack_bytes()
+
+   Unpacks and returns a variable length byte stream, similarly to
+   :meth:`unpack_string`.
+
+The following methods support unpacking arrays and lists:
+
+
+.. method:: Unpacker.unpack_list(unpack_item)
+
+   Unpacks and returns a list of homogeneous items.  The list is unpacked one
+   element at a time by first unpacking an unsigned integer flag.  If the flag is
+   ``1``, then the item is unpacked and appended to the list.  A flag of ``0``
+   indicates the end of the list.  *unpack_item* is the function that is called to
+   unpack the items.
+
+
+.. method:: Unpacker.unpack_farray(n, unpack_item)
+
+   Unpacks and returns (as a list) a fixed length array of homogeneous items.  *n*
+   is number of list elements to expect in the buffer. As above, *unpack_item* is
+   the function used to unpack each element.
+
+
+.. method:: Unpacker.unpack_array(unpack_item)
+
+   Unpacks and returns a variable length *list* of homogeneous items. First, the
+   length of the list is unpacked as an unsigned integer, then each element is
+   unpacked as in :meth:`unpack_farray` above.
+
+
+.. _xdr-exceptions:
+
+Exceptions
+----------
+
+Exceptions in this module are coded as class instances:
+
+
+.. exception:: Error
+
+   The base exception class.  :exc:`Error` has a single public data member
+   :attr:`msg` containing the description of the error.
+
+
+.. exception:: ConversionError
+
+   Class derived from :exc:`Error`.  Contains no additional instance variables.
+
+Here is an example of how you would catch one of these exceptions::
+
+   import xdrlib
+   p = xdrlib.Packer()
+   try:
+       p.pack_double(8.01)
+   except xdrlib.ConversionError as instance:
+       print 'packing the double failed:', instance.msg
+
diff --git a/Doc/library/xml.dom.minidom.rst b/Doc/library/xml.dom.minidom.rst
new file mode 100644
index 0000000..54c5f3d
--- /dev/null
+++ b/Doc/library/xml.dom.minidom.rst
@@ -0,0 +1,267 @@
+
+:mod:`xml.dom.minidom` --- Lightweight DOM implementation
+=========================================================
+
+.. module:: xml.dom.minidom
+   :synopsis: Lightweight Document Object Model (DOM) implementation.
+.. moduleauthor:: Paul Prescod <paul@prescod.net>
+.. sectionauthor:: Paul Prescod <paul@prescod.net>
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+
+
+.. versionadded:: 2.0
+
+:mod:`xml.dom.minidom` is a light-weight implementation of the Document Object
+Model interface.  It is intended to be simpler than the full DOM and also
+significantly smaller.
+
+DOM applications typically start by parsing some XML into a DOM.  With
+:mod:`xml.dom.minidom`, this is done through the parse functions::
+
+   from xml.dom.minidom import parse, parseString
+
+   dom1 = parse('c:\\temp\\mydata.xml') # parse an XML file by name
+
+   datasource = open('c:\\temp\\mydata.xml')
+   dom2 = parse(datasource)   # parse an open file
+
+   dom3 = parseString('<myxml>Some data<empty/> some more data</myxml>')
+
+The :func:`parse` function can take either a filename or an open file object.
+
+
+.. function:: parse(filename_or_file, parser)
+
+   Return a :class:`Document` from the given input. *filename_or_file* may be
+   either a file name, or a file-like object. *parser*, if given, must be a SAX2
+   parser object. This function will change the document handler of the parser and
+   activate namespace support; other parser configuration (like setting an entity
+   resolver) must have been done in advance.
+
+If you have XML in a string, you can use the :func:`parseString` function
+instead:
+
+
+.. function:: parseString(string[, parser])
+
+   Return a :class:`Document` that represents the *string*. This method creates a
+   :class:`StringIO` object for the string and passes that on to :func:`parse`.
+
+Both functions return a :class:`Document` object representing the content of the
+document.
+
+What the :func:`parse` and :func:`parseString` functions do is connect an XML
+parser with a "DOM builder" that can accept parse events from any SAX parser and
+convert them into a DOM tree.  The name of the functions are perhaps misleading,
+but are easy to grasp when learning the interfaces.  The parsing of the document
+will be completed before these functions return; it's simply that these
+functions do not provide a parser implementation themselves.
+
+You can also create a :class:`Document` by calling a method on a "DOM
+Implementation" object.  You can get this object either by calling the
+:func:`getDOMImplementation` function in the :mod:`xml.dom` package or the
+:mod:`xml.dom.minidom` module. Using the implementation from the
+:mod:`xml.dom.minidom` module will always return a :class:`Document` instance
+from the minidom implementation, while the version from :mod:`xml.dom` may
+provide an alternate implementation (this is likely if you have the `PyXML
+package <http://pyxml.sourceforge.net/>`_ installed).  Once you have a
+:class:`Document`, you can add child nodes to it to populate the DOM::
+
+   from xml.dom.minidom import getDOMImplementation
+
+   impl = getDOMImplementation()
+
+   newdoc = impl.createDocument(None, "some_tag", None)
+   top_element = newdoc.documentElement
+   text = newdoc.createTextNode('Some textual content.')
+   top_element.appendChild(text)
+
+Once you have a DOM document object, you can access the parts of your XML
+document through its properties and methods.  These properties are defined in
+the DOM specification.  The main property of the document object is the
+:attr:`documentElement` property.  It gives you the main element in the XML
+document: the one that holds all others.  Here is an example program::
+
+   dom3 = parseString("<myxml>Some data</myxml>")
+   assert dom3.documentElement.tagName == "myxml"
+
+When you are finished with a DOM, you should clean it up.  This is necessary
+because some versions of Python do not support garbage collection of objects
+that refer to each other in a cycle.  Until this restriction is removed from all
+versions of Python, it is safest to write your code as if cycles would not be
+cleaned up.
+
+The way to clean up a DOM is to call its :meth:`unlink` method::
+
+   dom1.unlink()
+   dom2.unlink()
+   dom3.unlink()
+
+:meth:`unlink` is a :mod:`xml.dom.minidom`\ -specific extension to the DOM API.
+After calling :meth:`unlink` on a node, the node and its descendants are
+essentially useless.
+
+
+.. seealso::
+
+   `Document Object Model (DOM) Level 1 Specification <http://www.w3.org/TR/REC-DOM-Level-1/>`_
+      The W3C recommendation for the DOM supported by :mod:`xml.dom.minidom`.
+
+
+.. _minidom-objects:
+
+DOM Objects
+-----------
+
+The definition of the DOM API for Python is given as part of the :mod:`xml.dom`
+module documentation.  This section lists the differences between the API and
+:mod:`xml.dom.minidom`.
+
+
+.. method:: Node.unlink()
+
+   Break internal references within the DOM so that it will be garbage collected on
+   versions of Python without cyclic GC.  Even when cyclic GC is available, using
+   this can make large amounts of memory available sooner, so calling this on DOM
+   objects as soon as they are no longer needed is good practice.  This only needs
+   to be called on the :class:`Document` object, but may be called on child nodes
+   to discard children of that node.
+
+
+.. method:: Node.writexml(writer[,indent=""[,addindent=""[,newl=""]]])
+
+   Write XML to the writer object.  The writer should have a :meth:`write` method
+   which matches that of the file object interface.  The *indent* parameter is the
+   indentation of the current node.  The *addindent* parameter is the incremental
+   indentation to use for subnodes of the current one.  The *newl* parameter
+   specifies the string to use to terminate newlines.
+
+   .. versionchanged:: 2.1
+      The optional keyword parameters *indent*, *addindent*, and *newl* were added to
+      support pretty output.
+
+   .. versionchanged:: 2.3
+      For the :class:`Document` node, an additional keyword argument *encoding* can be
+      used to specify the encoding field of the XML header.
+
+
+.. method:: Node.toxml([encoding])
+
+   Return the XML that the DOM represents as a string.
+
+   With no argument, the XML header does not specify an encoding, and the result is
+   Unicode string if the default encoding cannot represent all characters in the
+   document. Encoding this string in an encoding other than UTF-8 is likely
+   incorrect, since UTF-8 is the default encoding of XML.
+
+   With an explicit *encoding* argument, the result is a byte string in the
+   specified encoding. It is recommended that this argument is always specified. To
+   avoid :exc:`UnicodeError` exceptions in case of unrepresentable text data, the
+   encoding argument should be specified as "utf-8".
+
+   .. versionchanged:: 2.3
+      the *encoding* argument was introduced.
+
+
+.. method:: Node.toprettyxml([indent[, newl]])
+
+   Return a pretty-printed version of the document. *indent* specifies the
+   indentation string and defaults to a tabulator; *newl* specifies the string
+   emitted at the end of each line and defaults to ``\n``.
+
+   .. versionadded:: 2.1
+
+   .. versionchanged:: 2.3
+      the encoding argument; see :meth:`toxml`.
+
+The following standard DOM methods have special considerations with
+:mod:`xml.dom.minidom`:
+
+
+.. method:: Node.cloneNode(deep)
+
+   Although this method was present in the version of :mod:`xml.dom.minidom`
+   packaged with Python 2.0, it was seriously broken.  This has been corrected for
+   subsequent releases.
+
+
+.. _dom-example:
+
+DOM Example
+-----------
+
+This example program is a fairly realistic example of a simple program. In this
+particular case, we do not take much advantage of the flexibility of the DOM.
+
+.. literalinclude:: ../includes/minidom-example.py
+
+
+.. _minidom-and-dom:
+
+minidom and the DOM standard
+----------------------------
+
+The :mod:`xml.dom.minidom` module is essentially a DOM 1.0-compatible DOM with
+some DOM 2 features (primarily namespace features).
+
+Usage of the DOM interface in Python is straight-forward.  The following mapping
+rules apply:
+
+* Interfaces are accessed through instance objects. Applications should not
+  instantiate the classes themselves; they should use the creator functions
+  available on the :class:`Document` object. Derived interfaces support all
+  operations (and attributes) from the base interfaces, plus any new operations.
+
+* Operations are used as methods. Since the DOM uses only :keyword:`in`
+  parameters, the arguments are passed in normal order (from left to right).
+  There are no optional arguments. :keyword:`void` operations return ``None``.
+
+* IDL attributes map to instance attributes. For compatibility with the OMG IDL
+  language mapping for Python, an attribute ``foo`` can also be accessed through
+  accessor methods :meth:`_get_foo` and :meth:`_set_foo`.  :keyword:`readonly`
+  attributes must not be changed; this is not enforced at runtime.
+
+* The types ``short int``, ``unsigned int``, ``unsigned long long``, and
+  ``boolean`` all map to Python integer objects.
+
+* The type ``DOMString`` maps to Python strings. :mod:`xml.dom.minidom` supports
+  either byte or Unicode strings, but will normally produce Unicode strings.
+  Values of type ``DOMString`` may also be ``None`` where allowed to have the IDL
+  ``null`` value by the DOM specification from the W3C.
+
+* :keyword:`const` declarations map to variables in their respective scope (e.g.
+  ``xml.dom.minidom.Node.PROCESSING_INSTRUCTION_NODE``); they must not be changed.
+
+* ``DOMException`` is currently not supported in :mod:`xml.dom.minidom`.
+  Instead, :mod:`xml.dom.minidom` uses standard Python exceptions such as
+  :exc:`TypeError` and :exc:`AttributeError`.
+
+* :class:`NodeList` objects are implemented using Python's built-in list type.
+  Starting with Python 2.2, these objects provide the interface defined in the DOM
+  specification, but with earlier versions of Python they do not support the
+  official API.  They are, however, much more "Pythonic" than the interface
+  defined in the W3C recommendations.
+
+The following interfaces have no implementation in :mod:`xml.dom.minidom`:
+
+* :class:`DOMTimeStamp`
+
+* :class:`DocumentType` (added in Python 2.1)
+
+* :class:`DOMImplementation` (added in Python 2.1)
+
+* :class:`CharacterData`
+
+* :class:`CDATASection`
+
+* :class:`Notation`
+
+* :class:`Entity`
+
+* :class:`EntityReference`
+
+* :class:`DocumentFragment`
+
+Most of these reflect information in the XML document that is not of general
+utility to most DOM users.
+
diff --git a/Doc/library/xml.dom.pulldom.rst b/Doc/library/xml.dom.pulldom.rst
new file mode 100644
index 0000000..80a91b8
--- /dev/null
+++ b/Doc/library/xml.dom.pulldom.rst
@@ -0,0 +1,69 @@
+
+:mod:`xml.dom.pulldom` --- Support for building partial DOM trees
+=================================================================
+
+.. module:: xml.dom.pulldom
+   :synopsis: Support for building partial DOM trees from SAX events.
+.. moduleauthor:: Paul Prescod <paul@prescod.net>
+
+
+.. versionadded:: 2.0
+
+:mod:`xml.dom.pulldom` allows building only selected portions of a Document
+Object Model representation of a document from SAX events.
+
+
+.. class:: PullDOM([documentFactory])
+
+   :class:`xml.sax.handler.ContentHandler` implementation that ...
+
+
+.. class:: DOMEventStream(stream, parser, bufsize)
+
+   ...
+
+
+.. class:: SAX2DOM([documentFactory])
+
+   :class:`xml.sax.handler.ContentHandler` implementation that ...
+
+
+.. function:: parse(stream_or_string[, parser[, bufsize]])
+
+   ...
+
+
+.. function:: parseString(string[, parser])
+
+   ...
+
+
+.. data:: default_bufsize
+
+   Default value for the *bufsize* parameter to :func:`parse`.
+
+   .. versionchanged:: 2.1
+      The value of this variable can be changed before calling :func:`parse` and the
+      new value will take effect.
+
+
+.. _domeventstream-objects:
+
+DOMEventStream Objects
+----------------------
+
+
+.. method:: DOMEventStream.getEvent()
+
+   ...
+
+
+.. method:: DOMEventStream.expandNode(node)
+
+   ...
+
+
+.. method:: DOMEventStream.reset()
+
+   ...
+
diff --git a/Doc/library/xml.dom.rst b/Doc/library/xml.dom.rst
new file mode 100644
index 0000000..76f5cc1
--- /dev/null
+++ b/Doc/library/xml.dom.rst
@@ -0,0 +1,1045 @@
+
+:mod:`xml.dom` --- The Document Object Model API
+================================================
+
+.. module:: xml.dom
+   :synopsis: Document Object Model API for Python.
+.. sectionauthor:: Paul Prescod <paul@prescod.net>
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+
+
+.. versionadded:: 2.0
+
+The Document Object Model, or "DOM," is a cross-language API from the World Wide
+Web Consortium (W3C) for accessing and modifying XML documents.  A DOM
+implementation presents an XML document as a tree structure, or allows client
+code to build such a structure from scratch.  It then gives access to the
+structure through a set of objects which provided well-known interfaces.
+
+The DOM is extremely useful for random-access applications.  SAX only allows you
+a view of one bit of the document at a time.  If you are looking at one SAX
+element, you have no access to another.  If you are looking at a text node, you
+have no access to a containing element. When you write a SAX application, you
+need to keep track of your program's position in the document somewhere in your
+own code.  SAX does not do it for you.  Also, if you need to look ahead in the
+XML document, you are just out of luck.
+
+Some applications are simply impossible in an event driven model with no access
+to a tree.  Of course you could build some sort of tree yourself in SAX events,
+but the DOM allows you to avoid writing that code.  The DOM is a standard tree
+representation for XML data.
+
+The Document Object Model is being defined by the W3C in stages, or "levels" in
+their terminology.  The Python mapping of the API is substantially based on the
+DOM Level 2 recommendation.  The mapping of the Level 3 specification, currently
+only available in draft form, is being developed by the `Python XML Special
+Interest Group <http://www.python.org/sigs/xml-sig/>`_ as part of the `PyXML
+package <http://pyxml.sourceforge.net/>`_.  Refer to the documentation bundled
+with that package for information on the current state of DOM Level 3 support.
+
+.. % What if your needs are somewhere between SAX and the DOM?  Perhaps
+.. % you cannot afford to load the entire tree in memory but you find the
+.. % SAX model somewhat cumbersome and low-level.  There is also a module
+.. % called xml.dom.pulldom that allows you to build trees of only the
+.. % parts of a document that you need structured access to.  It also has
+.. % features that allow you to find your way around the DOM.
+.. % See http://www.prescod.net/python/pulldom
+
+DOM applications typically start by parsing some XML into a DOM.  How this is
+accomplished is not covered at all by DOM Level 1, and Level 2 provides only
+limited improvements: There is a :class:`DOMImplementation` object class which
+provides access to :class:`Document` creation methods, but no way to access an
+XML reader/parser/Document builder in an implementation-independent way. There
+is also no well-defined way to access these methods without an existing
+:class:`Document` object.  In Python, each DOM implementation will provide a
+function :func:`getDOMImplementation`. DOM Level 3 adds a Load/Store
+specification, which defines an interface to the reader, but this is not yet
+available in the Python standard library.
+
+Once you have a DOM document object, you can access the parts of your XML
+document through its properties and methods.  These properties are defined in
+the DOM specification; this portion of the reference manual describes the
+interpretation of the specification in Python.
+
+The specification provided by the W3C defines the DOM API for Java, ECMAScript,
+and OMG IDL.  The Python mapping defined here is based in large part on the IDL
+version of the specification, but strict compliance is not required (though
+implementations are free to support the strict mapping from IDL).  See section
+:ref:`dom-conformance` for a detailed discussion of mapping requirements.
+
+
+.. seealso::
+
+   `Document Object Model (DOM) Level 2 Specification <http://www.w3.org/TR/DOM-Level-2-Core/>`_
+      The W3C recommendation upon which the Python DOM API is based.
+
+   `Document Object Model (DOM) Level 1 Specification <http://www.w3.org/TR/REC-DOM-Level-1/>`_
+      The W3C recommendation for the DOM supported by :mod:`xml.dom.minidom`.
+
+   `PyXML <http://pyxml.sourceforge.net>`_
+      Users that require a full-featured implementation of DOM should use the PyXML
+      package.
+
+   `Python Language Mapping Specification <http://www.omg.org/docs/formal/02-11-05.pdf>`_
+      This specifies the mapping from OMG IDL to Python.
+
+
+Module Contents
+---------------
+
+The :mod:`xml.dom` contains the following functions:
+
+
+.. function:: registerDOMImplementation(name, factory)
+
+   Register the *factory* function with the name *name*.  The factory function
+   should return an object which implements the :class:`DOMImplementation`
+   interface.  The factory function can return the same object every time, or a new
+   one for each call, as appropriate for the specific implementation (e.g. if that
+   implementation supports some customization).
+
+
+.. function:: getDOMImplementation([name[, features]])
+
+   Return a suitable DOM implementation. The *name* is either well-known, the
+   module name of a DOM implementation, or ``None``. If it is not ``None``, imports
+   the corresponding module and returns a :class:`DOMImplementation` object if the
+   import succeeds.  If no name is given, and if the environment variable
+   :envvar:`PYTHON_DOM` is set, this variable is used to find the implementation.
+
+   If name is not given, this examines the available implementations to find one
+   with the required feature set.  If no implementation can be found, raise an
+   :exc:`ImportError`.  The features list must be a sequence of ``(feature,
+   version)`` pairs which are passed to the :meth:`hasFeature` method on available
+   :class:`DOMImplementation` objects.
+
+Some convenience constants are also provided:
+
+
+.. data:: EMPTY_NAMESPACE
+
+   The value used to indicate that no namespace is associated with a node in the
+   DOM.  This is typically found as the :attr:`namespaceURI` of a node, or used as
+   the *namespaceURI* parameter to a namespaces-specific method.
+
+   .. versionadded:: 2.2
+
+
+.. data:: XML_NAMESPACE
+
+   The namespace URI associated with the reserved prefix ``xml``, as defined by
+   `Namespaces in XML <http://www.w3.org/TR/REC-xml-names/>`_ (section 4).
+
+   .. versionadded:: 2.2
+
+
+.. data:: XMLNS_NAMESPACE
+
+   The namespace URI for namespace declarations, as defined by `Document Object
+   Model (DOM) Level 2 Core Specification
+   <http://www.w3.org/TR/DOM-Level-2-Core/core.html>`_ (section 1.1.8).
+
+   .. versionadded:: 2.2
+
+
+.. data:: XHTML_NAMESPACE
+
+   The URI of the XHTML namespace as defined by `XHTML 1.0: The Extensible
+   HyperText Markup Language <http://www.w3.org/TR/xhtml1/>`_ (section 3.1.1).
+
+   .. versionadded:: 2.2
+
+In addition, :mod:`xml.dom` contains a base :class:`Node` class and the DOM
+exception classes.  The :class:`Node` class provided by this module does not
+implement any of the methods or attributes defined by the DOM specification;
+concrete DOM implementations must provide those.  The :class:`Node` class
+provided as part of this module does provide the constants used for the
+:attr:`nodeType` attribute on concrete :class:`Node` objects; they are located
+within the class rather than at the module level to conform with the DOM
+specifications.
+
+.. % Should the Node documentation go here?
+
+
+.. _dom-objects:
+
+Objects in the DOM
+------------------
+
+The definitive documentation for the DOM is the DOM specification from the W3C.
+
+Note that DOM attributes may also be manipulated as nodes instead of as simple
+strings.  It is fairly rare that you must do this, however, so this usage is not
+yet documented.
+
++--------------------------------+-----------------------------------+---------------------------------+
+| Interface                      | Section                           | Purpose                         |
++================================+===================================+=================================+
+| :class:`DOMImplementation`     | :ref:`dom-implementation-objects` | Interface to the underlying     |
+|                                |                                   | implementation.                 |
++--------------------------------+-----------------------------------+---------------------------------+
+| :class:`Node`                  | :ref:`dom-node-objects`           | Base interface for most objects |
+|                                |                                   | in a document.                  |
++--------------------------------+-----------------------------------+---------------------------------+
+| :class:`NodeList`              | :ref:`dom-nodelist-objects`       | Interface for a sequence of     |
+|                                |                                   | nodes.                          |
++--------------------------------+-----------------------------------+---------------------------------+
+| :class:`DocumentType`          | :ref:`dom-documenttype-objects`   | Information about the           |
+|                                |                                   | declarations needed to process  |
+|                                |                                   | a document.                     |
++--------------------------------+-----------------------------------+---------------------------------+
+| :class:`Document`              | :ref:`dom-document-objects`       | Object which represents an      |
+|                                |                                   | entire document.                |
++--------------------------------+-----------------------------------+---------------------------------+
+| :class:`Element`               | :ref:`dom-element-objects`        | Element nodes in the document   |
+|                                |                                   | hierarchy.                      |
++--------------------------------+-----------------------------------+---------------------------------+
+| :class:`Attr`                  | :ref:`dom-attr-objects`           | Attribute value nodes on        |
+|                                |                                   | element nodes.                  |
++--------------------------------+-----------------------------------+---------------------------------+
+| :class:`Comment`               | :ref:`dom-comment-objects`        | Representation of comments in   |
+|                                |                                   | the source document.            |
++--------------------------------+-----------------------------------+---------------------------------+
+| :class:`Text`                  | :ref:`dom-text-objects`           | Nodes containing textual        |
+|                                |                                   | content from the document.      |
++--------------------------------+-----------------------------------+---------------------------------+
+| :class:`ProcessingInstruction` | :ref:`dom-pi-objects`             | Processing instruction          |
+|                                |                                   | representation.                 |
++--------------------------------+-----------------------------------+---------------------------------+
+
+An additional section describes the exceptions defined for working with the DOM
+in Python.
+
+
+.. _dom-implementation-objects:
+
+DOMImplementation Objects
+^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The :class:`DOMImplementation` interface provides a way for applications to
+determine the availability of particular features in the DOM they are using.
+DOM Level 2 added the ability to create new :class:`Document` and
+:class:`DocumentType` objects using the :class:`DOMImplementation` as well.
+
+
+.. method:: DOMImplementation.hasFeature(feature, version)
+
+   Return true if the feature identified by the pair of strings *feature* and
+   *version* is implemented.
+
+
+.. method:: DOMImplementation.createDocument(namespaceUri, qualifiedName, doctype)
+
+   Return a new :class:`Document` object (the root of the DOM), with a child
+   :class:`Element` object having the given *namespaceUri* and *qualifiedName*. The
+   *doctype* must be a :class:`DocumentType` object created by
+   :meth:`createDocumentType`, or ``None``. In the Python DOM API, the first two
+   arguments can also be ``None`` in order to indicate that no :class:`Element`
+   child is to be created.
+
+
+.. method:: DOMImplementation.createDocumentType(qualifiedName, publicId, systemId)
+
+   Return a new :class:`DocumentType` object that encapsulates the given
+   *qualifiedName*, *publicId*, and *systemId* strings, representing the
+   information contained in an XML document type declaration.
+
+
+.. _dom-node-objects:
+
+Node Objects
+^^^^^^^^^^^^
+
+All of the components of an XML document are subclasses of :class:`Node`.
+
+
+.. attribute:: Node.nodeType
+
+   An integer representing the node type.  Symbolic constants for the types are on
+   the :class:`Node` object: :const:`ELEMENT_NODE`, :const:`ATTRIBUTE_NODE`,
+   :const:`TEXT_NODE`, :const:`CDATA_SECTION_NODE`, :const:`ENTITY_NODE`,
+   :const:`PROCESSING_INSTRUCTION_NODE`, :const:`COMMENT_NODE`,
+   :const:`DOCUMENT_NODE`, :const:`DOCUMENT_TYPE_NODE`, :const:`NOTATION_NODE`.
+   This is a read-only attribute.
+
+
+.. attribute:: Node.parentNode
+
+   The parent of the current node, or ``None`` for the document node. The value is
+   always a :class:`Node` object or ``None``.  For :class:`Element` nodes, this
+   will be the parent element, except for the root element, in which case it will
+   be the :class:`Document` object. For :class:`Attr` nodes, this is always
+   ``None``. This is a read-only attribute.
+
+
+.. attribute:: Node.attributes
+
+   A :class:`NamedNodeMap` of attribute objects.  Only elements have actual values
+   for this; others provide ``None`` for this attribute. This is a read-only
+   attribute.
+
+
+.. attribute:: Node.previousSibling
+
+   The node that immediately precedes this one with the same parent.  For
+   instance the element with an end-tag that comes just before the *self*
+   element's start-tag.  Of course, XML documents are made up of more than just
+   elements so the previous sibling could be text, a comment, or something else.
+   If this node is the first child of the parent, this attribute will be
+   ``None``. This is a read-only attribute.
+
+
+.. attribute:: Node.nextSibling
+
+   The node that immediately follows this one with the same parent.  See also
+   :attr:`previousSibling`.  If this is the last child of the parent, this
+   attribute will be ``None``. This is a read-only attribute.
+
+
+.. attribute:: Node.childNodes
+
+   A list of nodes contained within this node. This is a read-only attribute.
+
+
+.. attribute:: Node.firstChild
+
+   The first child of the node, if there are any, or ``None``. This is a read-only
+   attribute.
+
+
+.. attribute:: Node.lastChild
+
+   The last child of the node, if there are any, or ``None``. This is a read-only
+   attribute.
+
+
+.. attribute:: Node.localName
+
+   The part of the :attr:`tagName` following the colon if there is one, else the
+   entire :attr:`tagName`.  The value is a string.
+
+
+.. attribute:: Node.prefix
+
+   The part of the :attr:`tagName` preceding the colon if there is one, else the
+   empty string.  The value is a string, or ``None``
+
+
+.. attribute:: Node.namespaceURI
+
+   The namespace associated with the element name.  This will be a string or
+   ``None``.  This is a read-only attribute.
+
+
+.. attribute:: Node.nodeName
+
+   This has a different meaning for each node type; see the DOM specification for
+   details.  You can always get the information you would get here from another
+   property such as the :attr:`tagName` property for elements or the :attr:`name`
+   property for attributes. For all node types, the value of this attribute will be
+   either a string or ``None``.  This is a read-only attribute.
+
+
+.. attribute:: Node.nodeValue
+
+   This has a different meaning for each node type; see the DOM specification for
+   details.  The situation is similar to that with :attr:`nodeName`.  The value is
+   a string or ``None``.
+
+
+.. method:: Node.hasAttributes()
+
+   Returns true if the node has any attributes.
+
+
+.. method:: Node.hasChildNodes()
+
+   Returns true if the node has any child nodes.
+
+
+.. method:: Node.isSameNode(other)
+
+   Returns true if *other* refers to the same node as this node. This is especially
+   useful for DOM implementations which use any sort of proxy architecture (because
+   more than one object can refer to the same node).
+
+   .. note::
+
+      This is based on a proposed DOM Level 3 API which is still in the "working
+      draft" stage, but this particular interface appears uncontroversial.  Changes
+      from the W3C will not necessarily affect this method in the Python DOM interface
+      (though any new W3C API for this would also be supported).
+
+
+.. method:: Node.appendChild(newChild)
+
+   Add a new child node to this node at the end of the list of children, returning
+   *newChild*.
+
+
+.. method:: Node.insertBefore(newChild, refChild)
+
+   Insert a new child node before an existing child.  It must be the case that
+   *refChild* is a child of this node; if not, :exc:`ValueError` is raised.
+   *newChild* is returned. If *refChild* is ``None``, it inserts *newChild* at the
+   end of the children's list.
+
+
+.. method:: Node.removeChild(oldChild)
+
+   Remove a child node.  *oldChild* must be a child of this node; if not,
+   :exc:`ValueError` is raised.  *oldChild* is returned on success.  If *oldChild*
+   will not be used further, its :meth:`unlink` method should be called.
+
+
+.. method:: Node.replaceChild(newChild, oldChild)
+
+   Replace an existing node with a new node. It must be the case that  *oldChild*
+   is a child of this node; if not, :exc:`ValueError` is raised.
+
+
+.. method:: Node.normalize()
+
+   Join adjacent text nodes so that all stretches of text are stored as single
+   :class:`Text` instances.  This simplifies processing text from a DOM tree for
+   many applications.
+
+   .. versionadded:: 2.1
+
+
+.. method:: Node.cloneNode(deep)
+
+   Clone this node.  Setting *deep* means to clone all child nodes as well.  This
+   returns the clone.
+
+
+.. _dom-nodelist-objects:
+
+NodeList Objects
+^^^^^^^^^^^^^^^^
+
+A :class:`NodeList` represents a sequence of nodes.  These objects are used in
+two ways in the DOM Core recommendation:  the :class:`Element` objects provides
+one as its list of child nodes, and the :meth:`getElementsByTagName` and
+:meth:`getElementsByTagNameNS` methods of :class:`Node` return objects with this
+interface to represent query results.
+
+The DOM Level 2 recommendation defines one method and one attribute for these
+objects:
+
+
+.. method:: NodeList.item(i)
+
+   Return the *i*'th item from the sequence, if there is one, or ``None``.  The
+   index *i* is not allowed to be less then zero or greater than or equal to the
+   length of the sequence.
+
+
+.. attribute:: NodeList.length
+
+   The number of nodes in the sequence.
+
+In addition, the Python DOM interface requires that some additional support is
+provided to allow :class:`NodeList` objects to be used as Python sequences.  All
+:class:`NodeList` implementations must include support for :meth:`__len__` and
+:meth:`__getitem__`; this allows iteration over the :class:`NodeList` in
+:keyword:`for` statements and proper support for the :func:`len` built-in
+function.
+
+If a DOM implementation supports modification of the document, the
+:class:`NodeList` implementation must also support the :meth:`__setitem__` and
+:meth:`__delitem__` methods.
+
+
+.. _dom-documenttype-objects:
+
+DocumentType Objects
+^^^^^^^^^^^^^^^^^^^^
+
+Information about the notations and entities declared by a document (including
+the external subset if the parser uses it and can provide the information) is
+available from a :class:`DocumentType` object.  The :class:`DocumentType` for a
+document is available from the :class:`Document` object's :attr:`doctype`
+attribute; if there is no ``DOCTYPE`` declaration for the document, the
+document's :attr:`doctype` attribute will be set to ``None`` instead of an
+instance of this interface.
+
+:class:`DocumentType` is a specialization of :class:`Node`, and adds the
+following attributes:
+
+
+.. attribute:: DocumentType.publicId
+
+   The public identifier for the external subset of the document type definition.
+   This will be a string or ``None``.
+
+
+.. attribute:: DocumentType.systemId
+
+   The system identifier for the external subset of the document type definition.
+   This will be a URI as a string, or ``None``.
+
+
+.. attribute:: DocumentType.internalSubset
+
+   A string giving the complete internal subset from the document. This does not
+   include the brackets which enclose the subset.  If the document has no internal
+   subset, this should be ``None``.
+
+
+.. attribute:: DocumentType.name
+
+   The name of the root element as given in the ``DOCTYPE`` declaration, if
+   present.
+
+
+.. attribute:: DocumentType.entities
+
+   This is a :class:`NamedNodeMap` giving the definitions of external entities.
+   For entity names defined more than once, only the first definition is provided
+   (others are ignored as required by the XML recommendation).  This may be
+   ``None`` if the information is not provided by the parser, or if no entities are
+   defined.
+
+
+.. attribute:: DocumentType.notations
+
+   This is a :class:`NamedNodeMap` giving the definitions of notations. For
+   notation names defined more than once, only the first definition is provided
+   (others are ignored as required by the XML recommendation).  This may be
+   ``None`` if the information is not provided by the parser, or if no notations
+   are defined.
+
+
+.. _dom-document-objects:
+
+Document Objects
+^^^^^^^^^^^^^^^^
+
+A :class:`Document` represents an entire XML document, including its constituent
+elements, attributes, processing instructions, comments etc.  Remeber that it
+inherits properties from :class:`Node`.
+
+
+.. attribute:: Document.documentElement
+
+   The one and only root element of the document.
+
+
+.. method:: Document.createElement(tagName)
+
+   Create and return a new element node.  The element is not inserted into the
+   document when it is created.  You need to explicitly insert it with one of the
+   other methods such as :meth:`insertBefore` or :meth:`appendChild`.
+
+
+.. method:: Document.createElementNS(namespaceURI, tagName)
+
+   Create and return a new element with a namespace.  The *tagName* may have a
+   prefix.  The element is not inserted into the document when it is created.  You
+   need to explicitly insert it with one of the other methods such as
+   :meth:`insertBefore` or :meth:`appendChild`.
+
+
+.. method:: Document.createTextNode(data)
+
+   Create and return a text node containing the data passed as a parameter.  As
+   with the other creation methods, this one does not insert the node into the
+   tree.
+
+
+.. method:: Document.createComment(data)
+
+   Create and return a comment node containing the data passed as a parameter.  As
+   with the other creation methods, this one does not insert the node into the
+   tree.
+
+
+.. method:: Document.createProcessingInstruction(target, data)
+
+   Create and return a processing instruction node containing the *target* and
+   *data* passed as parameters.  As with the other creation methods, this one does
+   not insert the node into the tree.
+
+
+.. method:: Document.createAttribute(name)
+
+   Create and return an attribute node.  This method does not associate the
+   attribute node with any particular element.  You must use
+   :meth:`setAttributeNode` on the appropriate :class:`Element` object to use the
+   newly created attribute instance.
+
+
+.. method:: Document.createAttributeNS(namespaceURI, qualifiedName)
+
+   Create and return an attribute node with a namespace.  The *tagName* may have a
+   prefix.  This method does not associate the attribute node with any particular
+   element.  You must use :meth:`setAttributeNode` on the appropriate
+   :class:`Element` object to use the newly created attribute instance.
+
+
+.. method:: Document.getElementsByTagName(tagName)
+
+   Search for all descendants (direct children, children's children, etc.) with a
+   particular element type name.
+
+
+.. method:: Document.getElementsByTagNameNS(namespaceURI, localName)
+
+   Search for all descendants (direct children, children's children, etc.) with a
+   particular namespace URI and localname.  The localname is the part of the
+   namespace after the prefix.
+
+
+.. _dom-element-objects:
+
+Element Objects
+^^^^^^^^^^^^^^^
+
+:class:`Element` is a subclass of :class:`Node`, so inherits all the attributes
+of that class.
+
+
+.. attribute:: Element.tagName
+
+   The element type name.  In a namespace-using document it may have colons in it.
+   The value is a string.
+
+
+.. method:: Element.getElementsByTagName(tagName)
+
+   Same as equivalent method in the :class:`Document` class.
+
+
+.. method:: Element.getElementsByTagNameNS(tagName)
+
+   Same as equivalent method in the :class:`Document` class.
+
+
+.. method:: Element.hasAttribute(name)
+
+   Returns true if the element has an attribute named by *name*.
+
+
+.. method:: Element.hasAttributeNS(namespaceURI, localName)
+
+   Returns true if the element has an attribute named by *namespaceURI* and
+   *localName*.
+
+
+.. method:: Element.getAttribute(name)
+
+   Return the value of the attribute named by *name* as a string. If no such
+   attribute exists, an empty string is returned, as if the attribute had no value.
+
+
+.. method:: Element.getAttributeNode(attrname)
+
+   Return the :class:`Attr` node for the attribute named by *attrname*.
+
+
+.. method:: Element.getAttributeNS(namespaceURI, localName)
+
+   Return the value of the attribute named by *namespaceURI* and *localName* as a
+   string. If no such attribute exists, an empty string is returned, as if the
+   attribute had no value.
+
+
+.. method:: Element.getAttributeNodeNS(namespaceURI, localName)
+
+   Return an attribute value as a node, given a *namespaceURI* and *localName*.
+
+
+.. method:: Element.removeAttribute(name)
+
+   Remove an attribute by name.  No exception is raised if there is no matching
+   attribute.
+
+
+.. method:: Element.removeAttributeNode(oldAttr)
+
+   Remove and return *oldAttr* from the attribute list, if present. If *oldAttr* is
+   not present, :exc:`NotFoundErr` is raised.
+
+
+.. method:: Element.removeAttributeNS(namespaceURI, localName)
+
+   Remove an attribute by name.  Note that it uses a localName, not a qname.  No
+   exception is raised if there is no matching attribute.
+
+
+.. method:: Element.setAttribute(name, value)
+
+   Set an attribute value from a string.
+
+
+.. method:: Element.setAttributeNode(newAttr)
+
+   Add a new attribute node to the element, replacing an existing attribute if
+   necessary if the :attr:`name` attribute matches.  If a replacement occurs, the
+   old attribute node will be returned.  If *newAttr* is already in use,
+   :exc:`InuseAttributeErr` will be raised.
+
+
+.. method:: Element.setAttributeNodeNS(newAttr)
+
+   Add a new attribute node to the element, replacing an existing attribute if
+   necessary if the :attr:`namespaceURI` and :attr:`localName` attributes match.
+   If a replacement occurs, the old attribute node will be returned.  If *newAttr*
+   is already in use, :exc:`InuseAttributeErr` will be raised.
+
+
+.. method:: Element.setAttributeNS(namespaceURI, qname, value)
+
+   Set an attribute value from a string, given a *namespaceURI* and a *qname*.
+   Note that a qname is the whole attribute name.  This is different than above.
+
+
+.. _dom-attr-objects:
+
+Attr Objects
+^^^^^^^^^^^^
+
+:class:`Attr` inherits from :class:`Node`, so inherits all its attributes.
+
+
+.. attribute:: Attr.name
+
+   The attribute name.  In a namespace-using document it may have colons in it.
+
+
+.. attribute:: Attr.localName
+
+   The part of the name following the colon if there is one, else the entire name.
+   This is a read-only attribute.
+
+
+.. attribute:: Attr.prefix
+
+   The part of the name preceding the colon if there is one, else the empty string.
+
+
+.. _dom-attributelist-objects:
+
+NamedNodeMap Objects
+^^^^^^^^^^^^^^^^^^^^
+
+:class:`NamedNodeMap` does *not* inherit from :class:`Node`.
+
+
+.. attribute:: NamedNodeMap.length
+
+   The length of the attribute list.
+
+
+.. method:: NamedNodeMap.item(index)
+
+   Return an attribute with a particular index.  The order you get the attributes
+   in is arbitrary but will be consistent for the life of a DOM.  Each item is an
+   attribute node.  Get its value with the :attr:`value` attribute.
+
+There are also experimental methods that give this class more mapping behavior.
+You can use them or you can use the standardized :meth:`getAttribute\*` family
+of methods on the :class:`Element` objects.
+
+
+.. _dom-comment-objects:
+
+Comment Objects
+^^^^^^^^^^^^^^^
+
+:class:`Comment` represents a comment in the XML document.  It is a subclass of
+:class:`Node`, but cannot have child nodes.
+
+
+.. attribute:: Comment.data
+
+   The content of the comment as a string.  The attribute contains all characters
+   between the leading ``<!-``\ ``-`` and trailing ``-``\ ``->``, but does not
+   include them.
+
+
+.. _dom-text-objects:
+
+Text and CDATASection Objects
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The :class:`Text` interface represents text in the XML document.  If the parser
+and DOM implementation support the DOM's XML extension, portions of the text
+enclosed in CDATA marked sections are stored in :class:`CDATASection` objects.
+These two interfaces are identical, but provide different values for the
+:attr:`nodeType` attribute.
+
+These interfaces extend the :class:`Node` interface.  They cannot have child
+nodes.
+
+
+.. attribute:: Text.data
+
+   The content of the text node as a string.
+
+.. note::
+
+   The use of a :class:`CDATASection` node does not indicate that the node
+   represents a complete CDATA marked section, only that the content of the node
+   was part of a CDATA section.  A single CDATA section may be represented by more
+   than one node in the document tree.  There is no way to determine whether two
+   adjacent :class:`CDATASection` nodes represent different CDATA marked sections.
+
+
+.. _dom-pi-objects:
+
+ProcessingInstruction Objects
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+Represents a processing instruction in the XML document; this inherits from the
+:class:`Node` interface and cannot have child nodes.
+
+
+.. attribute:: ProcessingInstruction.target
+
+   The content of the processing instruction up to the first whitespace character.
+   This is a read-only attribute.
+
+
+.. attribute:: ProcessingInstruction.data
+
+   The content of the processing instruction following the first whitespace
+   character.
+
+
+.. _dom-exceptions:
+
+Exceptions
+^^^^^^^^^^
+
+.. versionadded:: 2.1
+
+The DOM Level 2 recommendation defines a single exception, :exc:`DOMException`,
+and a number of constants that allow applications to determine what sort of
+error occurred. :exc:`DOMException` instances carry a :attr:`code` attribute
+that provides the appropriate value for the specific exception.
+
+The Python DOM interface provides the constants, but also expands the set of
+exceptions so that a specific exception exists for each of the exception codes
+defined by the DOM.  The implementations must raise the appropriate specific
+exception, each of which carries the appropriate value for the :attr:`code`
+attribute.
+
+
+.. exception:: DOMException
+
+   Base exception class used for all specific DOM exceptions.  This exception class
+   cannot be directly instantiated.
+
+
+.. exception:: DomstringSizeErr
+
+   Raised when a specified range of text does not fit into a string. This is not
+   known to be used in the Python DOM implementations, but may be received from DOM
+   implementations not written in Python.
+
+
+.. exception:: HierarchyRequestErr
+
+   Raised when an attempt is made to insert a node where the node type is not
+   allowed.
+
+
+.. exception:: IndexSizeErr
+
+   Raised when an index or size parameter to a method is negative or exceeds the
+   allowed values.
+
+
+.. exception:: InuseAttributeErr
+
+   Raised when an attempt is made to insert an :class:`Attr` node that is already
+   present elsewhere in the document.
+
+
+.. exception:: InvalidAccessErr
+
+   Raised if a parameter or an operation is not supported on the underlying object.
+
+
+.. exception:: InvalidCharacterErr
+
+   This exception is raised when a string parameter contains a character that is
+   not permitted in the context it's being used in by the XML 1.0 recommendation.
+   For example, attempting to create an :class:`Element` node with a space in the
+   element type name will cause this error to be raised.
+
+
+.. exception:: InvalidModificationErr
+
+   Raised when an attempt is made to modify the type of a node.
+
+
+.. exception:: InvalidStateErr
+
+   Raised when an attempt is made to use an object that is not defined or is no
+   longer usable.
+
+
+.. exception:: NamespaceErr
+
+   If an attempt is made to change any object in a way that is not permitted with
+   regard to the `Namespaces in XML <http://www.w3.org/TR/REC-xml-names/>`_
+   recommendation, this exception is raised.
+
+
+.. exception:: NotFoundErr
+
+   Exception when a node does not exist in the referenced context.  For example,
+   :meth:`NamedNodeMap.removeNamedItem` will raise this if the node passed in does
+   not exist in the map.
+
+
+.. exception:: NotSupportedErr
+
+   Raised when the implementation does not support the requested type of object or
+   operation.
+
+
+.. exception:: NoDataAllowedErr
+
+   This is raised if data is specified for a node which does not support data.
+
+   .. % XXX  a better explanation is needed!
+
+
+.. exception:: NoModificationAllowedErr
+
+   Raised on attempts to modify an object where modifications are not allowed (such
+   as for read-only nodes).
+
+
+.. exception:: SyntaxErr
+
+   Raised when an invalid or illegal string is specified.
+
+   .. % XXX  how is this different from InvalidCharacterErr ???
+
+
+.. exception:: WrongDocumentErr
+
+   Raised when a node is inserted in a different document than it currently belongs
+   to, and the implementation does not support migrating the node from one document
+   to the other.
+
+The exception codes defined in the DOM recommendation map to the exceptions
+described above according to this table:
+
++--------------------------------------+---------------------------------+
+| Constant                             | Exception                       |
++======================================+=================================+
+| :const:`DOMSTRING_SIZE_ERR`          | :exc:`DomstringSizeErr`         |
++--------------------------------------+---------------------------------+
+| :const:`HIERARCHY_REQUEST_ERR`       | :exc:`HierarchyRequestErr`      |
++--------------------------------------+---------------------------------+
+| :const:`INDEX_SIZE_ERR`              | :exc:`IndexSizeErr`             |
++--------------------------------------+---------------------------------+
+| :const:`INUSE_ATTRIBUTE_ERR`         | :exc:`InuseAttributeErr`        |
++--------------------------------------+---------------------------------+
+| :const:`INVALID_ACCESS_ERR`          | :exc:`InvalidAccessErr`         |
++--------------------------------------+---------------------------------+
+| :const:`INVALID_CHARACTER_ERR`       | :exc:`InvalidCharacterErr`      |
++--------------------------------------+---------------------------------+
+| :const:`INVALID_MODIFICATION_ERR`    | :exc:`InvalidModificationErr`   |
++--------------------------------------+---------------------------------+
+| :const:`INVALID_STATE_ERR`           | :exc:`InvalidStateErr`          |
++--------------------------------------+---------------------------------+
+| :const:`NAMESPACE_ERR`               | :exc:`NamespaceErr`             |
++--------------------------------------+---------------------------------+
+| :const:`NOT_FOUND_ERR`               | :exc:`NotFoundErr`              |
++--------------------------------------+---------------------------------+
+| :const:`NOT_SUPPORTED_ERR`           | :exc:`NotSupportedErr`          |
++--------------------------------------+---------------------------------+
+| :const:`NO_DATA_ALLOWED_ERR`         | :exc:`NoDataAllowedErr`         |
++--------------------------------------+---------------------------------+
+| :const:`NO_MODIFICATION_ALLOWED_ERR` | :exc:`NoModificationAllowedErr` |
++--------------------------------------+---------------------------------+
+| :const:`SYNTAX_ERR`                  | :exc:`SyntaxErr`                |
++--------------------------------------+---------------------------------+
+| :const:`WRONG_DOCUMENT_ERR`          | :exc:`WrongDocumentErr`         |
++--------------------------------------+---------------------------------+
+
+
+.. _dom-conformance:
+
+Conformance
+-----------
+
+This section describes the conformance requirements and relationships between
+the Python DOM API, the W3C DOM recommendations, and the OMG IDL mapping for
+Python.
+
+
+.. _dom-type-mapping:
+
+Type Mapping
+^^^^^^^^^^^^
+
+The primitive IDL types used in the DOM specification are mapped to Python types
+according to the following table.
+
++------------------+-------------------------------------------+
+| IDL Type         | Python Type                               |
++==================+===========================================+
+| ``boolean``      | ``IntegerType`` (with a value of ``0`` or |
+|                  | ``1``)                                    |
++------------------+-------------------------------------------+
+| ``int``          | ``IntegerType``                           |
++------------------+-------------------------------------------+
+| ``long int``     | ``IntegerType``                           |
++------------------+-------------------------------------------+
+| ``unsigned int`` | ``IntegerType``                           |
++------------------+-------------------------------------------+
+
+Additionally, the :class:`DOMString` defined in the recommendation is mapped to
+a Python string or Unicode string.  Applications should be able to handle
+Unicode whenever a string is returned from the DOM.
+
+The IDL :keyword:`null` value is mapped to ``None``, which may be accepted or
+provided by the implementation whenever :keyword:`null` is allowed by the API.
+
+
+.. _dom-accessor-methods:
+
+Accessor Methods
+^^^^^^^^^^^^^^^^
+
+The mapping from OMG IDL to Python defines accessor functions for IDL
+:keyword:`attribute` declarations in much the way the Java mapping does.
+Mapping the IDL declarations ::
+
+   readonly attribute string someValue;
+            attribute string anotherValue;
+
+yields three accessor functions:  a "get" method for :attr:`someValue`
+(:meth:`_get_someValue`), and "get" and "set" methods for :attr:`anotherValue`
+(:meth:`_get_anotherValue` and :meth:`_set_anotherValue`).  The mapping, in
+particular, does not require that the IDL attributes are accessible as normal
+Python attributes:  ``object.someValue`` is *not* required to work, and may
+raise an :exc:`AttributeError`.
+
+The Python DOM API, however, *does* require that normal attribute access work.
+This means that the typical surrogates generated by Python IDL compilers are not
+likely to work, and wrapper objects may be needed on the client if the DOM
+objects are accessed via CORBA. While this does require some additional
+consideration for CORBA DOM clients, the implementers with experience using DOM
+over CORBA from Python do not consider this a problem.  Attributes that are
+declared :keyword:`readonly` may not restrict write access in all DOM
+implementations.
+
+In the Python DOM API, accessor functions are not required.  If provided, they
+should take the form defined by the Python IDL mapping, but these methods are
+considered unnecessary since the attributes are accessible directly from Python.
+"Set" accessors should never be provided for :keyword:`readonly` attributes.
+
+The IDL definitions do not fully embody the requirements of the W3C DOM API,
+such as the notion of certain objects, such as the return value of
+:meth:`getElementsByTagName`, being "live".  The Python DOM API does not require
+implementations to enforce such requirements.
+
diff --git a/Doc/library/xml.etree.elementtree.rst b/Doc/library/xml.etree.elementtree.rst
new file mode 100644
index 0000000..ead8d29
--- /dev/null
+++ b/Doc/library/xml.etree.elementtree.rst
@@ -0,0 +1,444 @@
+
+:mod:`xml.etree.ElementTree` --- The ElementTree XML API
+========================================================
+
+.. module:: xml.etree.ElementTree
+   :synopsis: Implementation of the ElementTree API.
+.. moduleauthor:: Fredrik Lundh <fredrik@pythonware.com>
+
+
+.. versionadded:: 2.5
+
+The Element type is a flexible container object, designed to store hierarchical
+data structures in memory. The type can be described as a cross between a list
+and a dictionary.
+
+Each element has a number of properties associated with it:
+
+* a tag which is a string identifying what kind of data this element represents
+  (the element type, in other words).
+
+* a number of attributes, stored in a Python dictionary.
+
+* a text string.
+
+* an optional tail string.
+
+* a number of child elements, stored in a Python sequence
+
+To create an element instance, use the Element or SubElement factory functions.
+
+The :class:`ElementTree` class can be used to wrap an element structure, and
+convert it from and to XML.
+
+A C implementation of this API is available as :mod:`xml.etree.cElementTree`.
+
+
+.. _elementtree-functions:
+
+Functions
+---------
+
+
+.. function:: Comment([text])
+
+   Comment element factory.  This factory function creates a special element that
+   will be serialized as an XML comment. The comment string can be either an 8-bit
+   ASCII string or a Unicode string. *text* is a string containing the comment
+   string. Returns an element instance representing a comment.
+
+
+.. function:: dump(elem)
+
+   Writes an element tree or element structure to sys.stdout.  This function should
+   be used for debugging only.
+
+   The exact output format is implementation dependent.  In this version, it's
+   written as an ordinary XML file.
+
+   *elem* is an element tree or an individual element.
+
+
+.. function:: Element(tag[, attrib][, **extra])
+
+   Element factory.  This function returns an object implementing the standard
+   Element interface.  The exact class or type of that object is implementation
+   dependent, but it will always be compatible with the _ElementInterface class in
+   this module.
+
+   The element name, attribute names, and attribute values can be either 8-bit
+   ASCII strings or Unicode strings. *tag* is the element name. *attrib* is an
+   optional dictionary, containing element attributes. *extra* contains additional
+   attributes, given as keyword arguments. Returns an element instance.
+
+
+.. function:: fromstring(text)
+
+   Parses an XML section from a string constant.  Same as XML. *text* is a string
+   containing XML data. Returns an Element instance.
+
+
+.. function:: iselement(element)
+
+   Checks if an object appears to be a valid element object. *element* is an
+   element instance. Returns a true value if this is an element object.
+
+
+.. function:: iterparse(source[, events])
+
+   Parses an XML section into an element tree incrementally, and reports what's
+   going on to the user. *source* is a filename or file object containing XML data.
+   *events* is a list of events to report back.  If omitted, only "end" events are
+   reported. Returns an iterator providing ``(event, elem)`` pairs.
+
+
+.. function:: parse(source[, parser])
+
+   Parses an XML section into an element tree. *source* is a filename or file
+   object containing XML data. *parser* is an optional parser instance.  If not
+   given, the standard XMLTreeBuilder parser is used. Returns an ElementTree
+   instance.
+
+
+.. function:: ProcessingInstruction(target[, text])
+
+   PI element factory.  This factory function creates a special element that will
+   be serialized as an XML processing instruction. *target* is a string containing
+   the PI target. *text* is a string containing the PI contents, if given. Returns
+   an element instance, representing a processing instruction.
+
+
+.. function:: SubElement(parent, tag[, attrib[,  **extra]])
+
+   Subelement factory.  This function creates an element instance, and appends it
+   to an existing element.
+
+   The element name, attribute names, and attribute values can be either 8-bit
+   ASCII strings or Unicode strings. *parent* is the parent element. *tag* is the
+   subelement name. *attrib* is an optional dictionary, containing element
+   attributes. *extra* contains additional attributes, given as keyword arguments.
+   Returns an element instance.
+
+
+.. function:: tostring(element[, encoding])
+
+   Generates a string representation of an XML element, including all subelements.
+   *element* is an Element instance. *encoding* is the output encoding (default is
+   US-ASCII). Returns an encoded string containing the XML data.
+
+
+.. function:: XML(text)
+
+   Parses an XML section from a string constant.  This function can be used to
+   embed "XML literals" in Python code. *text* is a string containing XML data.
+   Returns an Element instance.
+
+
+.. function:: XMLID(text)
+
+   Parses an XML section from a string constant, and also returns a dictionary
+   which maps from element id:s to elements. *text* is a string containing XML
+   data. Returns a tuple containing an Element instance and a dictionary.
+
+
+.. _elementtree-element-interface:
+
+The Element Interface
+---------------------
+
+Element objects returned by Element or SubElement have the  following methods
+and attributes.
+
+
+.. attribute:: Element.tag
+
+   A string identifying what kind of data this element represents (the element
+   type, in other words).
+
+
+.. attribute:: Element.text
+
+   The *text* attribute can be used to hold additional data associated with the
+   element. As the name implies this attribute is usually a string but may be any
+   application-specific object. If the element is created from an XML file the
+   attribute will contain any text found between the element tags.
+
+
+.. attribute:: Element.tail
+
+   The *tail* attribute can be used to hold additional data associated with the
+   element. This attribute is usually a string but may be any application-specific
+   object. If the element is created from an XML file the attribute will contain
+   any text found after the element's end tag and before the next tag.
+
+
+.. attribute:: Element.attrib
+
+   A dictionary containing the element's attributes. Note that while the *attrib*
+   value is always a real mutable Python dictionary, an ElementTree implementation
+   may choose to use another internal representation, and create the dictionary
+   only if someone asks for it. To take advantage of such implementations, use the
+   dictionary methods below whenever possible.
+
+The following dictionary-like methods work on the element attributes.
+
+
+.. method:: Element.clear()
+
+   Resets an element.  This function removes all subelements, clears all
+   attributes, and sets the text and tail attributes to None.
+
+
+.. method:: Element.get(key[, default=None])
+
+   Gets the element attribute named *key*.
+
+   Returns the attribute value, or *default* if the attribute was not found.
+
+
+.. method:: Element.items()
+
+   Returns the element attributes as a sequence of (name, value) pairs. The
+   attributes are returned in an arbitrary order.
+
+
+.. method:: Element.keys()
+
+   Returns the elements attribute names as a list. The names are returned in an
+   arbitrary order.
+
+
+.. method:: Element.set(key, value)
+
+   Set the attribute *key* on the element to *value*.
+
+The following methods work on the element's children (subelements).
+
+
+.. method:: Element.append(subelement)
+
+   Adds the element *subelement* to the end of this elements internal list of
+   subelements.
+
+
+.. method:: Element.find(match)
+
+   Finds the first subelement matching *match*.  *match* may be a tag name or path.
+   Returns an element instance or ``None``.
+
+
+.. method:: Element.findall(match)
+
+   Finds all subelements matching *match*.  *match* may be a tag name or path.
+   Returns an iterable yielding all matching elements in document order.
+
+
+.. method:: Element.findtext(condition[, default=None])
+
+   Finds text for the first subelement matching *condition*.  *condition* may be a
+   tag name or path. Returns the text content of the first matching element, or
+   *default* if no element was found.  Note that if the matching element has no
+   text content an empty string is returned.
+
+
+.. method:: Element.getchildren()
+
+   Returns all subelements.  The elements are returned in document order.
+
+
+.. method:: Element.getiterator([tag=None])
+
+   Creates a tree iterator with the current element as the root.   The iterator
+   iterates over this element and all elements below it  that match the given tag.
+   If tag is ``None`` or ``'*'`` then all elements are iterated over. Returns an
+   iterable that provides element objects in document (depth first) order.
+
+
+.. method:: Element.insert(index, element)
+
+   Inserts a subelement at the given position in this element.
+
+
+.. method:: Element.makeelement(tag, attrib)
+
+   Creates a new element object of the same type as this element. Do not call this
+   method, use the SubElement factory function instead.
+
+
+.. method:: Element.remove(subelement)
+
+   Removes *subelement* from the element.   Unlike the findXYZ methods this method
+   compares elements based on  the instance identity, not on tag value or contents.
+
+Element objects also support the following sequence type methods for working
+with subelements: :meth:`__delitem__`, :meth:`__getitem__`, :meth:`__setitem__`,
+:meth:`__len__`.
+
+Caution: Because Element objects do not define a :meth:`__nonzero__` method,
+elements with no subelements will test as ``False``. ::
+
+   element = root.find('foo')
+
+   if not element: # careful!
+       print "element not found, or element has no subelements"
+
+   if element is None:
+       print "element not found"
+
+
+.. _elementtree-elementtree-objects:
+
+ElementTree Objects
+-------------------
+
+
+.. class:: ElementTree([element,] [file])
+
+   ElementTree wrapper class.  This class represents an entire element hierarchy,
+   and adds some extra support for serialization to and from standard XML.
+
+   *element* is the root element. The tree is initialized with the contents of the
+   XML *file* if given.
+
+
+.. method:: ElementTree._setroot(element)
+
+   Replaces the root element for this tree.  This discards the current contents of
+   the tree, and replaces it with the given element.  Use with care. *element* is
+   an element instance.
+
+
+.. method:: ElementTree.find(path)
+
+   Finds the first toplevel element with given tag. Same as getroot().find(path).
+   *path* is the element to look for. Returns the first matching element, or
+   ``None`` if no element was found.
+
+
+.. method:: ElementTree.findall(path)
+
+   Finds all toplevel elements with the given tag. Same as getroot().findall(path).
+   *path* is the element to look for. Returns a list or iterator containing all
+   matching elements, in document order.
+
+
+.. method:: ElementTree.findtext(path[, default])
+
+   Finds the element text for the first toplevel element with given tag.  Same as
+   getroot().findtext(path). *path* is the toplevel element to look for. *default*
+   is the value to return if the element was not found. Returns the text content of
+   the first matching element, or the default value no element was found.  Note
+   that if the element has is found, but has no text content, this method returns
+   an empty string.
+
+
+.. method:: ElementTree.getiterator([tag])
+
+   Creates and returns a tree iterator for the root element.  The iterator loops
+   over all elements in this tree, in section order. *tag* is the tag to look for
+   (default is to return all elements)
+
+
+.. method:: ElementTree.getroot()
+
+   Returns the root element for this tree.
+
+
+.. method:: ElementTree.parse(source[, parser])
+
+   Loads an external XML section into this element tree. *source* is a file name or
+   file object. *parser* is an optional parser instance.  If not given, the
+   standard XMLTreeBuilder parser is used. Returns the section root element.
+
+
+.. method:: ElementTree.write(file[, encoding])
+
+   Writes the element tree to a file, as XML. *file* is a file name, or a file
+   object opened for writing. *encoding* is the output encoding (default is
+   US-ASCII).
+
+
+.. _elementtree-qname-objects:
+
+QName Objects
+-------------
+
+
+.. class:: QName(text_or_uri[, tag])
+
+   QName wrapper.  This can be used to wrap a QName attribute value, in order to
+   get proper namespace handling on output. *text_or_uri* is a string containing
+   the QName value, in the form {uri}local, or, if the tag argument is given, the
+   URI part of a QName. If *tag* is given, the first argument is interpreted as an
+   URI, and this argument is interpreted as a local name. :class:`QName` instances
+   are opaque.
+
+
+.. _elementtree-treebuilder-objects:
+
+TreeBuilder Objects
+-------------------
+
+
+.. class:: TreeBuilder([element_factory])
+
+   Generic element structure builder.  This builder converts a sequence of start,
+   data, and end method calls to a well-formed element structure. You can use this
+   class to build an element structure using a custom XML parser, or a parser for
+   some other XML-like format. The *element_factory* is called to create new
+   Element instances when given.
+
+
+.. method:: TreeBuilder.close()
+
+   Flushes the parser buffers, and returns the toplevel documen element. Returns an
+   Element instance.
+
+
+.. method:: TreeBuilder.data(data)
+
+   Adds text to the current element. *data* is a string.  This should be either an
+   8-bit string containing ASCII text, or a Unicode string.
+
+
+.. method:: TreeBuilder.end(tag)
+
+   Closes the current element. *tag* is the element name. Returns the closed
+   element.
+
+
+.. method:: TreeBuilder.start(tag, attrs)
+
+   Opens a new element. *tag* is the element name. *attrs* is a dictionary
+   containing element attributes. Returns the opened element.
+
+
+.. _elementtree-xmltreebuilder-objects:
+
+XMLTreeBuilder Objects
+----------------------
+
+
+.. class:: XMLTreeBuilder([html,] [target])
+
+   Element structure builder for XML source data, based on the expat parser. *html*
+   are predefined HTML entities.  This flag is not supported by the current
+   implementation. *target* is the target object.  If omitted, the builder uses an
+   instance of the standard TreeBuilder class.
+
+
+.. method:: XMLTreeBuilder.close()
+
+   Finishes feeding data to the parser. Returns an element structure.
+
+
+.. method:: XMLTreeBuilder.doctype(name, pubid, system)
+
+   Handles a doctype declaration. *name* is the doctype name. *pubid* is the public
+   identifier. *system* is the system identifier.
+
+
+.. method:: XMLTreeBuilder.feed(data)
+
+   Feeds data to the parser. *data* is encoded data.
+
diff --git a/Doc/library/xml.etree.rst b/Doc/library/xml.etree.rst
new file mode 100644
index 0000000..e14c5f9
--- /dev/null
+++ b/Doc/library/xml.etree.rst
@@ -0,0 +1,25 @@
+:mod:`xml.etree` --- The ElementTree API for XML
+================================================
+
+.. module:: xml.etree
+   :synopsis: Package containing common ElementTree modules.
+.. moduleauthor:: Fredrik Lundh <fredrik@pythonware.com>
+
+
+.. versionadded:: 2.5
+
+The ElementTree package is a simple, efficient, and quite popular  library for
+XML manipulation in Python.    The :mod:`xml.etree` package contains the most
+common components  from the ElementTree API library.  In the current release,
+this package contains the :mod:`ElementTree`,  :mod:`ElementPath`, and
+:mod:`ElementInclude` modules from the full  ElementTree distribution.
+
+.. % XXX To be continued!
+
+
+.. seealso::
+
+   `ElementTree Overview <http://effbot.org/tag/elementtree>`_
+      The home page for :mod:`ElementTree`.  This includes links  to additional
+      documentation, alternative implementations, and  other add-ons.
+
diff --git a/Doc/library/xml.sax.handler.rst b/Doc/library/xml.sax.handler.rst
new file mode 100644
index 0000000..bc287d1
--- /dev/null
+++ b/Doc/library/xml.sax.handler.rst
@@ -0,0 +1,402 @@
+
+:mod:`xml.sax.handler` --- Base classes for SAX handlers
+========================================================
+
+.. module:: xml.sax.handler
+   :synopsis: Base classes for SAX event handlers.
+.. moduleauthor:: Lars Marius Garshol <larsga@garshol.priv.no>
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+
+
+.. versionadded:: 2.0
+
+The SAX API defines four kinds of handlers: content handlers, DTD handlers,
+error handlers, and entity resolvers. Applications normally only need to
+implement those interfaces whose events they are interested in; they can
+implement the interfaces in a single object or in multiple objects. Handler
+implementations should inherit from the base classes provided in the module
+:mod:`xml.sax.handler`, so that all methods get default implementations.
+
+
+.. class:: ContentHandler
+
+   This is the main callback interface in SAX, and the one most important to
+   applications. The order of events in this interface mirrors the order of the
+   information in the document.
+
+
+.. class:: DTDHandler
+
+   Handle DTD events.
+
+   This interface specifies only those DTD events required for basic parsing
+   (unparsed entities and attributes).
+
+
+.. class:: EntityResolver
+
+   Basic interface for resolving entities. If you create an object implementing
+   this interface, then register the object with your Parser, the parser will call
+   the method in your object to resolve all external entities.
+
+
+.. class:: ErrorHandler
+
+   Interface used by the parser to present error and warning messages to the
+   application.  The methods of this object control whether errors are immediately
+   converted to exceptions or are handled in some other way.
+
+In addition to these classes, :mod:`xml.sax.handler` provides symbolic constants
+for the feature and property names.
+
+
+.. data:: feature_namespaces
+
+   Value: ``"http://xml.org/sax/features/namespaces"`` ---  true: Perform Namespace
+   processing. ---  false: Optionally do not perform Namespace processing (implies
+   namespace-prefixes; default). ---  access: (parsing) read-only; (not parsing)
+   read/write
+
+
+.. data:: feature_namespace_prefixes
+
+   Value: ``"http://xml.org/sax/features/namespace-prefixes"`` --- true: Report
+   the original prefixed names and attributes used for Namespace
+   declarations. --- false: Do not report attributes used for Namespace
+   declarations, and optionally do not report original prefixed names
+   (default). --- access: (parsing) read-only; (not parsing) read/write
+
+
+.. data:: feature_string_interning
+
+   Value: ``"http://xml.org/sax/features/string-interning"`` ---  true: All element
+   names, prefixes, attribute names, Namespace URIs, and local names are interned
+   using the built-in intern function. ---  false: Names are not necessarily
+   interned, although they may be (default). ---  access: (parsing) read-only; (not
+   parsing) read/write
+
+
+.. data:: feature_validation
+
+   Value: ``"http://xml.org/sax/features/validation"`` --- true: Report all
+   validation errors (implies external-general-entities and
+   external-parameter-entities). --- false: Do not report validation errors. ---
+   access: (parsing) read-only; (not parsing) read/write
+
+
+.. data:: feature_external_ges
+
+   Value: ``"http://xml.org/sax/features/external-general-entities"`` ---  true:
+   Include all external general (text) entities. ---  false: Do not include
+   external general entities. ---  access: (parsing) read-only; (not parsing)
+   read/write
+
+
+.. data:: feature_external_pes
+
+   Value: ``"http://xml.org/sax/features/external-parameter-entities"`` ---  true:
+   Include all external parameter entities, including the external DTD subset. ---
+   false: Do not include any external parameter entities, even the external DTD
+   subset. ---  access: (parsing) read-only; (not parsing) read/write
+
+
+.. data:: all_features
+
+   List of all features.
+
+
+.. data:: property_lexical_handler
+
+   Value: ``"http://xml.org/sax/properties/lexical-handler"`` ---  data type:
+   xml.sax.sax2lib.LexicalHandler (not supported in Python 2) ---  description: An
+   optional extension handler for lexical events like comments. ---  access:
+   read/write
+
+
+.. data:: property_declaration_handler
+
+   Value: ``"http://xml.org/sax/properties/declaration-handler"`` ---  data type:
+   xml.sax.sax2lib.DeclHandler (not supported in Python 2) ---  description: An
+   optional extension handler for DTD-related events other than notations and
+   unparsed entities. ---  access: read/write
+
+
+.. data:: property_dom_node
+
+   Value: ``"http://xml.org/sax/properties/dom-node"`` ---  data type:
+   org.w3c.dom.Node (not supported in Python 2)  ---  description: When parsing,
+   the current DOM node being visited if this is a DOM iterator; when not parsing,
+   the root DOM node for iteration. ---  access: (parsing) read-only; (not parsing)
+   read/write
+
+
+.. data:: property_xml_string
+
+   Value: ``"http://xml.org/sax/properties/xml-string"`` ---  data type: String ---
+   description: The literal string of characters that was the source for the
+   current event. ---  access: read-only
+
+
+.. data:: all_properties
+
+   List of all known property names.
+
+
+.. _content-handler-objects:
+
+ContentHandler Objects
+----------------------
+
+Users are expected to subclass :class:`ContentHandler` to support their
+application.  The following methods are called by the parser on the appropriate
+events in the input document:
+
+
+.. method:: ContentHandler.setDocumentLocator(locator)
+
+   Called by the parser to give the application a locator for locating the origin
+   of document events.
+
+   SAX parsers are strongly encouraged (though not absolutely required) to supply a
+   locator: if it does so, it must supply the locator to the application by
+   invoking this method before invoking any of the other methods in the
+   DocumentHandler interface.
+
+   The locator allows the application to determine the end position of any
+   document-related event, even if the parser is not reporting an error. Typically,
+   the application will use this information for reporting its own errors (such as
+   character content that does not match an application's business rules). The
+   information returned by the locator is probably not sufficient for use with a
+   search engine.
+
+   Note that the locator will return correct information only during the invocation
+   of the events in this interface. The application should not attempt to use it at
+   any other time.
+
+
+.. method:: ContentHandler.startDocument()
+
+   Receive notification of the beginning of a document.
+
+   The SAX parser will invoke this method only once, before any other methods in
+   this interface or in DTDHandler (except for :meth:`setDocumentLocator`).
+
+
+.. method:: ContentHandler.endDocument()
+
+   Receive notification of the end of a document.
+
+   The SAX parser will invoke this method only once, and it will be the last method
+   invoked during the parse. The parser shall not invoke this method until it has
+   either abandoned parsing (because of an unrecoverable error) or reached the end
+   of input.
+
+
+.. method:: ContentHandler.startPrefixMapping(prefix, uri)
+
+   Begin the scope of a prefix-URI Namespace mapping.
+
+   The information from this event is not necessary for normal Namespace
+   processing: the SAX XML reader will automatically replace prefixes for element
+   and attribute names when the ``feature_namespaces`` feature is enabled (the
+   default).
+
+   There are cases, however, when applications need to use prefixes in character
+   data or in attribute values, where they cannot safely be expanded automatically;
+   the :meth:`startPrefixMapping` and :meth:`endPrefixMapping` events supply the
+   information to the application to expand prefixes in those contexts itself, if
+   necessary.
+
+   .. % XXX This is not really the default, is it? MvL
+
+   Note that :meth:`startPrefixMapping` and :meth:`endPrefixMapping` events are not
+   guaranteed to be properly nested relative to each-other: all
+   :meth:`startPrefixMapping` events will occur before the corresponding
+   :meth:`startElement` event, and all :meth:`endPrefixMapping` events will occur
+   after the corresponding :meth:`endElement` event, but their order is not
+   guaranteed.
+
+
+.. method:: ContentHandler.endPrefixMapping(prefix)
+
+   End the scope of a prefix-URI mapping.
+
+   See :meth:`startPrefixMapping` for details. This event will always occur after
+   the corresponding :meth:`endElement` event, but the order of
+   :meth:`endPrefixMapping` events is not otherwise guaranteed.
+
+
+.. method:: ContentHandler.startElement(name, attrs)
+
+   Signals the start of an element in non-namespace mode.
+
+   The *name* parameter contains the raw XML 1.0 name of the element type as a
+   string and the *attrs* parameter holds an object of the :class:`Attributes`
+   interface (see :ref:`attributes-objects`) containing the attributes of
+   the element.  The object passed as *attrs* may be re-used by the parser; holding
+   on to a reference to it is not a reliable way to keep a copy of the attributes.
+   To keep a copy of the attributes, use the :meth:`copy` method of the *attrs*
+   object.
+
+
+.. method:: ContentHandler.endElement(name)
+
+   Signals the end of an element in non-namespace mode.
+
+   The *name* parameter contains the name of the element type, just as with the
+   :meth:`startElement` event.
+
+
+.. method:: ContentHandler.startElementNS(name, qname, attrs)
+
+   Signals the start of an element in namespace mode.
+
+   The *name* parameter contains the name of the element type as a ``(uri,
+   localname)`` tuple, the *qname* parameter contains the raw XML 1.0 name used in
+   the source document, and the *attrs* parameter holds an instance of the
+   :class:`AttributesNS` interface (see :ref:`attributes-ns-objects`)
+   containing the attributes of the element.  If no namespace is associated with
+   the element, the *uri* component of *name* will be ``None``.  The object passed
+   as *attrs* may be re-used by the parser; holding on to a reference to it is not
+   a reliable way to keep a copy of the attributes.  To keep a copy of the
+   attributes, use the :meth:`copy` method of the *attrs* object.
+
+   Parsers may set the *qname* parameter to ``None``, unless the
+   ``feature_namespace_prefixes`` feature is activated.
+
+
+.. method:: ContentHandler.endElementNS(name, qname)
+
+   Signals the end of an element in namespace mode.
+
+   The *name* parameter contains the name of the element type, just as with the
+   :meth:`startElementNS` method, likewise the *qname* parameter.
+
+
+.. method:: ContentHandler.characters(content)
+
+   Receive notification of character data.
+
+   The Parser will call this method to report each chunk of character data. SAX
+   parsers may return all contiguous character data in a single chunk, or they may
+   split it into several chunks; however, all of the characters in any single event
+   must come from the same external entity so that the Locator provides useful
+   information.
+
+   *content* may be a Unicode string or a byte string; the ``expat`` reader module
+   produces always Unicode strings.
+
+   .. note::
+
+      The earlier SAX 1 interface provided by the Python XML Special Interest Group
+      used a more Java-like interface for this method.  Since most parsers used from
+      Python did not take advantage of the older interface, the simpler signature was
+      chosen to replace it.  To convert old code to the new interface, use *content*
+      instead of slicing content with the old *offset* and *length* parameters.
+
+
+.. method:: ContentHandler.ignorableWhitespace(whitespace)
+
+   Receive notification of ignorable whitespace in element content.
+
+   Validating Parsers must use this method to report each chunk of ignorable
+   whitespace (see the W3C XML 1.0 recommendation, section 2.10): non-validating
+   parsers may also use this method if they are capable of parsing and using
+   content models.
+
+   SAX parsers may return all contiguous whitespace in a single chunk, or they may
+   split it into several chunks; however, all of the characters in any single event
+   must come from the same external entity, so that the Locator provides useful
+   information.
+
+
+.. method:: ContentHandler.processingInstruction(target, data)
+
+   Receive notification of a processing instruction.
+
+   The Parser will invoke this method once for each processing instruction found:
+   note that processing instructions may occur before or after the main document
+   element.
+
+   A SAX parser should never report an XML declaration (XML 1.0, section 2.8) or a
+   text declaration (XML 1.0, section 4.3.1) using this method.
+
+
+.. method:: ContentHandler.skippedEntity(name)
+
+   Receive notification of a skipped entity.
+
+   The Parser will invoke this method once for each entity skipped. Non-validating
+   processors may skip entities if they have not seen the declarations (because,
+   for example, the entity was declared in an external DTD subset). All processors
+   may skip external entities, depending on the values of the
+   ``feature_external_ges`` and the ``feature_external_pes`` properties.
+
+
+.. _dtd-handler-objects:
+
+DTDHandler Objects
+------------------
+
+:class:`DTDHandler` instances provide the following methods:
+
+
+.. method:: DTDHandler.notationDecl(name, publicId, systemId)
+
+   Handle a notation declaration event.
+
+
+.. method:: DTDHandler.unparsedEntityDecl(name, publicId, systemId, ndata)
+
+   Handle an unparsed entity declaration event.
+
+
+.. _entity-resolver-objects:
+
+EntityResolver Objects
+----------------------
+
+
+.. method:: EntityResolver.resolveEntity(publicId, systemId)
+
+   Resolve the system identifier of an entity and return either the system
+   identifier to read from as a string, or an InputSource to read from. The default
+   implementation returns *systemId*.
+
+
+.. _sax-error-handler:
+
+ErrorHandler Objects
+--------------------
+
+Objects with this interface are used to receive error and warning information
+from the :class:`XMLReader`.  If you create an object that implements this
+interface, then register the object with your :class:`XMLReader`, the parser
+will call the methods in your object to report all warnings and errors. There
+are three levels of errors available: warnings, (possibly) recoverable errors,
+and unrecoverable errors.  All methods take a :exc:`SAXParseException` as the
+only parameter.  Errors and warnings may be converted to an exception by raising
+the passed-in exception object.
+
+
+.. method:: ErrorHandler.error(exception)
+
+   Called when the parser encounters a recoverable error.  If this method does not
+   raise an exception, parsing may continue, but further document information
+   should not be expected by the application.  Allowing the parser to continue may
+   allow additional errors to be discovered in the input document.
+
+
+.. method:: ErrorHandler.fatalError(exception)
+
+   Called when the parser encounters an error it cannot recover from; parsing is
+   expected to terminate when this method returns.
+
+
+.. method:: ErrorHandler.warning(exception)
+
+   Called when the parser presents minor warning information to the application.
+   Parsing is expected to continue when this method returns, and document
+   information will continue to be passed to the application. Raising an exception
+   in this method will cause parsing to end.
+
diff --git a/Doc/library/xml.sax.reader.rst b/Doc/library/xml.sax.reader.rst
new file mode 100644
index 0000000..d64a4fc
--- /dev/null
+++ b/Doc/library/xml.sax.reader.rst
@@ -0,0 +1,386 @@
+
+:mod:`xml.sax.xmlreader` --- Interface for XML parsers
+======================================================
+
+.. module:: xml.sax.xmlreader
+   :synopsis: Interface which SAX-compliant XML parsers must implement.
+.. moduleauthor:: Lars Marius Garshol <larsga@garshol.priv.no>
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+
+
+.. versionadded:: 2.0
+
+SAX parsers implement the :class:`XMLReader` interface. They are implemented in
+a Python module, which must provide a function :func:`create_parser`. This
+function is invoked by  :func:`xml.sax.make_parser` with no arguments to create
+a new  parser object.
+
+
+.. class:: XMLReader()
+
+   Base class which can be inherited by SAX parsers.
+
+
+.. class:: IncrementalParser()
+
+   In some cases, it is desirable not to parse an input source at once, but to feed
+   chunks of the document as they get available. Note that the reader will normally
+   not read the entire file, but read it in chunks as well; still :meth:`parse`
+   won't return until the entire document is processed. So these interfaces should
+   be used if the blocking behaviour of :meth:`parse` is not desirable.
+
+   When the parser is instantiated it is ready to begin accepting data from the
+   feed method immediately. After parsing has been finished with a call to close
+   the reset method must be called to make the parser ready to accept new data,
+   either from feed or using the parse method.
+
+   Note that these methods must *not* be called during parsing, that is, after
+   parse has been called and before it returns.
+
+   By default, the class also implements the parse method of the XMLReader
+   interface using the feed, close and reset methods of the IncrementalParser
+   interface as a convenience to SAX 2.0 driver writers.
+
+
+.. class:: Locator()
+
+   Interface for associating a SAX event with a document location. A locator object
+   will return valid results only during calls to DocumentHandler methods; at any
+   other time, the results are unpredictable. If information is not available,
+   methods may return ``None``.
+
+
+.. class:: InputSource([systemId])
+
+   Encapsulation of the information needed by the :class:`XMLReader` to read
+   entities.
+
+   This class may include information about the public identifier, system
+   identifier, byte stream (possibly with character encoding information) and/or
+   the character stream of an entity.
+
+   Applications will create objects of this class for use in the
+   :meth:`XMLReader.parse` method and for returning from
+   EntityResolver.resolveEntity.
+
+   An :class:`InputSource` belongs to the application, the :class:`XMLReader` is
+   not allowed to modify :class:`InputSource` objects passed to it from the
+   application, although it may make copies and modify those.
+
+
+.. class:: AttributesImpl(attrs)
+
+   This is an implementation of the :class:`Attributes` interface (see section
+   :ref:`attributes-objects`).  This is a dictionary-like object which
+   represents the element attributes in a :meth:`startElement` call. In addition
+   to the most useful dictionary operations, it supports a number of other
+   methods as described by the interface. Objects of this class should be
+   instantiated by readers; *attrs* must be a dictionary-like object containing
+   a mapping from attribute names to attribute values.
+
+
+.. class:: AttributesNSImpl(attrs, qnames)
+
+   Namespace-aware variant of :class:`AttributesImpl`, which will be passed to
+   :meth:`startElementNS`. It is derived from :class:`AttributesImpl`, but
+   understands attribute names as two-tuples of *namespaceURI* and
+   *localname*. In addition, it provides a number of methods expecting qualified
+   names as they appear in the original document.  This class implements the
+   :class:`AttributesNS` interface (see section :ref:`attributes-ns-objects`).
+
+
+.. _xmlreader-objects:
+
+XMLReader Objects
+-----------------
+
+The :class:`XMLReader` interface supports the following methods:
+
+
+.. method:: XMLReader.parse(source)
+
+   Process an input source, producing SAX events. The *source* object can be a
+   system identifier (a string identifying the input source -- typically a file
+   name or an URL), a file-like object, or an :class:`InputSource` object. When
+   :meth:`parse` returns, the input is completely processed, and the parser object
+   can be discarded or reset. As a limitation, the current implementation only
+   accepts byte streams; processing of character streams is for further study.
+
+
+.. method:: XMLReader.getContentHandler()
+
+   Return the current :class:`ContentHandler`.
+
+
+.. method:: XMLReader.setContentHandler(handler)
+
+   Set the current :class:`ContentHandler`.  If no :class:`ContentHandler` is set,
+   content events will be discarded.
+
+
+.. method:: XMLReader.getDTDHandler()
+
+   Return the current :class:`DTDHandler`.
+
+
+.. method:: XMLReader.setDTDHandler(handler)
+
+   Set the current :class:`DTDHandler`.  If no :class:`DTDHandler` is set, DTD
+   events will be discarded.
+
+
+.. method:: XMLReader.getEntityResolver()
+
+   Return the current :class:`EntityResolver`.
+
+
+.. method:: XMLReader.setEntityResolver(handler)
+
+   Set the current :class:`EntityResolver`.  If no :class:`EntityResolver` is set,
+   attempts to resolve an external entity will result in opening the system
+   identifier for the entity, and fail if it is not available.
+
+
+.. method:: XMLReader.getErrorHandler()
+
+   Return the current :class:`ErrorHandler`.
+
+
+.. method:: XMLReader.setErrorHandler(handler)
+
+   Set the current error handler.  If no :class:`ErrorHandler` is set, errors will
+   be raised as exceptions, and warnings will be printed.
+
+
+.. method:: XMLReader.setLocale(locale)
+
+   Allow an application to set the locale for errors and warnings.
+
+   SAX parsers are not required to provide localization for errors and warnings; if
+   they cannot support the requested locale, however, they must throw a SAX
+   exception.  Applications may request a locale change in the middle of a parse.
+
+
+.. method:: XMLReader.getFeature(featurename)
+
+   Return the current setting for feature *featurename*.  If the feature is not
+   recognized, :exc:`SAXNotRecognizedException` is raised. The well-known
+   featurenames are listed in the module :mod:`xml.sax.handler`.
+
+
+.. method:: XMLReader.setFeature(featurename, value)
+
+   Set the *featurename* to *value*. If the feature is not recognized,
+   :exc:`SAXNotRecognizedException` is raised. If the feature or its setting is not
+   supported by the parser, *SAXNotSupportedException* is raised.
+
+
+.. method:: XMLReader.getProperty(propertyname)
+
+   Return the current setting for property *propertyname*. If the property is not
+   recognized, a :exc:`SAXNotRecognizedException` is raised. The well-known
+   propertynames are listed in the module :mod:`xml.sax.handler`.
+
+
+.. method:: XMLReader.setProperty(propertyname, value)
+
+   Set the *propertyname* to *value*. If the property is not recognized,
+   :exc:`SAXNotRecognizedException` is raised. If the property or its setting is
+   not supported by the parser, *SAXNotSupportedException* is raised.
+
+
+.. _incremental-parser-objects:
+
+IncrementalParser Objects
+-------------------------
+
+Instances of :class:`IncrementalParser` offer the following additional methods:
+
+
+.. method:: IncrementalParser.feed(data)
+
+   Process a chunk of *data*.
+
+
+.. method:: IncrementalParser.close()
+
+   Assume the end of the document. That will check well-formedness conditions that
+   can be checked only at the end, invoke handlers, and may clean up resources
+   allocated during parsing.
+
+
+.. method:: IncrementalParser.reset()
+
+   This method is called after close has been called to reset the parser so that it
+   is ready to parse new documents. The results of calling parse or feed after
+   close without calling reset are undefined.
+
+
+.. _locator-objects:
+
+Locator Objects
+---------------
+
+Instances of :class:`Locator` provide these methods:
+
+
+.. method:: Locator.getColumnNumber()
+
+   Return the column number where the current event ends.
+
+
+.. method:: Locator.getLineNumber()
+
+   Return the line number where the current event ends.
+
+
+.. method:: Locator.getPublicId()
+
+   Return the public identifier for the current event.
+
+
+.. method:: Locator.getSystemId()
+
+   Return the system identifier for the current event.
+
+
+.. _input-source-objects:
+
+InputSource Objects
+-------------------
+
+
+.. method:: InputSource.setPublicId(id)
+
+   Sets the public identifier of this :class:`InputSource`.
+
+
+.. method:: InputSource.getPublicId()
+
+   Returns the public identifier of this :class:`InputSource`.
+
+
+.. method:: InputSource.setSystemId(id)
+
+   Sets the system identifier of this :class:`InputSource`.
+
+
+.. method:: InputSource.getSystemId()
+
+   Returns the system identifier of this :class:`InputSource`.
+
+
+.. method:: InputSource.setEncoding(encoding)
+
+   Sets the character encoding of this :class:`InputSource`.
+
+   The encoding must be a string acceptable for an XML encoding declaration (see
+   section 4.3.3 of the XML recommendation).
+
+   The encoding attribute of the :class:`InputSource` is ignored if the
+   :class:`InputSource` also contains a character stream.
+
+
+.. method:: InputSource.getEncoding()
+
+   Get the character encoding of this InputSource.
+
+
+.. method:: InputSource.setByteStream(bytefile)
+
+   Set the byte stream (a Python file-like object which does not perform
+   byte-to-character conversion) for this input source.
+
+   The SAX parser will ignore this if there is also a character stream specified,
+   but it will use a byte stream in preference to opening a URI connection itself.
+
+   If the application knows the character encoding of the byte stream, it should
+   set it with the setEncoding method.
+
+
+.. method:: InputSource.getByteStream()
+
+   Get the byte stream for this input source.
+
+   The getEncoding method will return the character encoding for this byte stream,
+   or None if unknown.
+
+
+.. method:: InputSource.setCharacterStream(charfile)
+
+   Set the character stream for this input source. (The stream must be a Python 1.6
+   Unicode-wrapped file-like that performs conversion to Unicode strings.)
+
+   If there is a character stream specified, the SAX parser will ignore any byte
+   stream and will not attempt to open a URI connection to the system identifier.
+
+
+.. method:: InputSource.getCharacterStream()
+
+   Get the character stream for this input source.
+
+
+.. _attributes-objects:
+
+The :class:`Attributes` Interface
+---------------------------------
+
+:class:`Attributes` objects implement a portion of the mapping protocol,
+including the methods :meth:`copy`, :meth:`get`, :meth:`has_key`, :meth:`items`,
+:meth:`keys`, and :meth:`values`.  The following methods are also provided:
+
+
+.. method:: Attributes.getLength()
+
+   Return the number of attributes.
+
+
+.. method:: Attributes.getNames()
+
+   Return the names of the attributes.
+
+
+.. method:: Attributes.getType(name)
+
+   Returns the type of the attribute *name*, which is normally ``'CDATA'``.
+
+
+.. method:: Attributes.getValue(name)
+
+   Return the value of attribute *name*.
+
+.. % getValueByQName, getNameByQName, getQNameByName, getQNames available
+.. % here already, but documented only for derived class.
+
+
+.. _attributes-ns-objects:
+
+The :class:`AttributesNS` Interface
+-----------------------------------
+
+This interface is a subtype of the :class:`Attributes` interface (see section
+:ref:`attributes-objects`).  All methods supported by that interface are also
+available on :class:`AttributesNS` objects.
+
+The following methods are also available:
+
+
+.. method:: AttributesNS.getValueByQName(name)
+
+   Return the value for a qualified name.
+
+
+.. method:: AttributesNS.getNameByQName(name)
+
+   Return the ``(namespace, localname)`` pair for a qualified *name*.
+
+
+.. method:: AttributesNS.getQNameByName(name)
+
+   Return the qualified name for a ``(namespace, localname)`` pair.
+
+
+.. method:: AttributesNS.getQNames()
+
+   Return the qualified names of all attributes.
+
diff --git a/Doc/library/xml.sax.rst b/Doc/library/xml.sax.rst
new file mode 100644
index 0000000..43d17c2
--- /dev/null
+++ b/Doc/library/xml.sax.rst
@@ -0,0 +1,143 @@
+
+:mod:`xml.sax` --- Support for SAX2 parsers
+===========================================
+
+.. module:: xml.sax
+   :synopsis: Package containing SAX2 base classes and convenience functions.
+.. moduleauthor:: Lars Marius Garshol <larsga@garshol.priv.no>
+.. sectionauthor:: Fred L. Drake, Jr. <fdrake@acm.org>
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+
+
+.. versionadded:: 2.0
+
+The :mod:`xml.sax` package provides a number of modules which implement the
+Simple API for XML (SAX) interface for Python.  The package itself provides the
+SAX exceptions and the convenience functions which will be most used by users of
+the SAX API.
+
+The convenience functions are:
+
+
+.. function:: make_parser([parser_list])
+
+   Create and return a SAX :class:`XMLReader` object.  The first parser found will
+   be used.  If *parser_list* is provided, it must be a sequence of strings which
+   name modules that have a function named :func:`create_parser`.  Modules listed
+   in *parser_list* will be used before modules in the default list of parsers.
+
+
+.. function:: parse(filename_or_stream, handler[, error_handler])
+
+   Create a SAX parser and use it to parse a document.  The document, passed in as
+   *filename_or_stream*, can be a filename or a file object.  The *handler*
+   parameter needs to be a SAX :class:`ContentHandler` instance.  If
+   *error_handler* is given, it must be a SAX :class:`ErrorHandler` instance; if
+   omitted,  :exc:`SAXParseException` will be raised on all errors.  There is no
+   return value; all work must be done by the *handler* passed in.
+
+
+.. function:: parseString(string, handler[, error_handler])
+
+   Similar to :func:`parse`, but parses from a buffer *string* received as a
+   parameter.
+
+A typical SAX application uses three kinds of objects: readers, handlers and
+input sources.  "Reader" in this context is another term for parser, i.e. some
+piece of code that reads the bytes or characters from the input source, and
+produces a sequence of events. The events then get distributed to the handler
+objects, i.e. the reader invokes a method on the handler.  A SAX application
+must therefore obtain a reader object, create or open the input sources, create
+the handlers, and connect these objects all together.  As the final step of
+preparation, the reader is called to parse the input. During parsing, methods on
+the handler objects are called based on structural and syntactic events from the
+input data.
+
+For these objects, only the interfaces are relevant; they are normally not
+instantiated by the application itself.  Since Python does not have an explicit
+notion of interface, they are formally introduced as classes, but applications
+may use implementations which do not inherit from the provided classes.  The
+:class:`InputSource`, :class:`Locator`, :class:`Attributes`,
+:class:`AttributesNS`, and :class:`XMLReader` interfaces are defined in the
+module :mod:`xml.sax.xmlreader`.  The handler interfaces are defined in
+:mod:`xml.sax.handler`.  For convenience, :class:`InputSource` (which is often
+instantiated directly) and the handler classes are also available from
+:mod:`xml.sax`.  These interfaces are described below.
+
+In addition to these classes, :mod:`xml.sax` provides the following exception
+classes.
+
+
+.. exception:: SAXException(msg[, exception])
+
+   Encapsulate an XML error or warning.  This class can contain basic error or
+   warning information from either the XML parser or the application: it can be
+   subclassed to provide additional functionality or to add localization.  Note
+   that although the handlers defined in the :class:`ErrorHandler` interface
+   receive instances of this exception, it is not required to actually raise the
+   exception --- it is also useful as a container for information.
+
+   When instantiated, *msg* should be a human-readable description of the error.
+   The optional *exception* parameter, if given, should be ``None`` or an exception
+   that was caught by the parsing code and is being passed along as information.
+
+   This is the base class for the other SAX exception classes.
+
+
+.. exception:: SAXParseException(msg, exception, locator)
+
+   Subclass of :exc:`SAXException` raised on parse errors. Instances of this class
+   are passed to the methods of the SAX :class:`ErrorHandler` interface to provide
+   information about the parse error.  This class supports the SAX :class:`Locator`
+   interface as well as the :class:`SAXException` interface.
+
+
+.. exception:: SAXNotRecognizedException(msg[, exception])
+
+   Subclass of :exc:`SAXException` raised when a SAX :class:`XMLReader` is
+   confronted with an unrecognized feature or property.  SAX applications and
+   extensions may use this class for similar purposes.
+
+
+.. exception:: SAXNotSupportedException(msg[, exception])
+
+   Subclass of :exc:`SAXException` raised when a SAX :class:`XMLReader` is asked to
+   enable a feature that is not supported, or to set a property to a value that the
+   implementation does not support.  SAX applications and extensions may use this
+   class for similar purposes.
+
+
+.. seealso::
+
+   `SAX: The Simple API for XML <http://www.saxproject.org/>`_
+      This site is the focal point for the definition of the SAX API.  It provides a
+      Java implementation and online documentation.  Links to implementations and
+      historical information are also available.
+
+   Module :mod:`xml.sax.handler`
+      Definitions of the interfaces for application-provided objects.
+
+   Module :mod:`xml.sax.saxutils`
+      Convenience functions for use in SAX applications.
+
+   Module :mod:`xml.sax.xmlreader`
+      Definitions of the interfaces for parser-provided objects.
+
+
+.. _sax-exception-objects:
+
+SAXException Objects
+--------------------
+
+The :class:`SAXException` exception class supports the following methods:
+
+
+.. method:: SAXException.getMessage()
+
+   Return a human-readable message describing the error condition.
+
+
+.. method:: SAXException.getException()
+
+   Return an encapsulated exception object, or ``None``.
+
diff --git a/Doc/library/xml.sax.utils.rst b/Doc/library/xml.sax.utils.rst
new file mode 100644
index 0000000..0585a9b
--- /dev/null
+++ b/Doc/library/xml.sax.utils.rst
@@ -0,0 +1,83 @@
+
+:mod:`xml.sax.saxutils` --- SAX Utilities
+=========================================
+
+.. module:: xml.sax.saxutils
+   :synopsis: Convenience functions and classes for use with SAX.
+.. moduleauthor:: Lars Marius Garshol <larsga@garshol.priv.no>
+.. sectionauthor:: Martin v. Löwis <martin@v.loewis.de>
+
+
+.. versionadded:: 2.0
+
+The module :mod:`xml.sax.saxutils` contains a number of classes and functions
+that are commonly useful when creating SAX applications, either in direct use,
+or as base classes.
+
+
+.. function:: escape(data[, entities])
+
+   Escape ``'&'``, ``'<'``, and ``'>'`` in a string of data.
+
+   You can escape other strings of data by passing a dictionary as the optional
+   *entities* parameter.  The keys and values must all be strings; each key will be
+   replaced with its corresponding value.
+
+
+.. function:: unescape(data[, entities])
+
+   Unescape ``'&amp;'``, ``'&lt;'``, and ``'&gt;'`` in a string of data.
+
+   You can unescape other strings of data by passing a dictionary as the optional
+   *entities* parameter.  The keys and values must all be strings; each key will be
+   replaced with its corresponding value.
+
+   .. versionadded:: 2.3
+
+
+.. function:: quoteattr(data[, entities])
+
+   Similar to :func:`escape`, but also prepares *data* to be used as an
+   attribute value.  The return value is a quoted version of *data* with any
+   additional required replacements. :func:`quoteattr` will select a quote
+   character based on the content of *data*, attempting to avoid encoding any
+   quote characters in the string.  If both single- and double-quote characters
+   are already in *data*, the double-quote characters will be encoded and *data*
+   will be wrapped in double-quotes.  The resulting string can be used directly
+   as an attribute value::
+
+      >>> print "<element attr=%s>" % quoteattr("ab ' cd \" ef")
+      <element attr="ab ' cd &quot; ef">
+
+   This function is useful when generating attribute values for HTML or any SGML
+   using the reference concrete syntax.
+
+   .. versionadded:: 2.2
+
+
+.. class:: XMLGenerator([out[, encoding]])
+
+   This class implements the :class:`ContentHandler` interface by writing SAX
+   events back into an XML document. In other words, using an :class:`XMLGenerator`
+   as the content handler will reproduce the original document being parsed. *out*
+   should be a file-like object which will default to *sys.stdout*. *encoding* is
+   the encoding of the output stream which defaults to ``'iso-8859-1'``.
+
+
+.. class:: XMLFilterBase(base)
+
+   This class is designed to sit between an :class:`XMLReader` and the client
+   application's event handlers.  By default, it does nothing but pass requests up
+   to the reader and events on to the handlers unmodified, but subclasses can
+   override specific methods to modify the event stream or the configuration
+   requests as they pass through.
+
+
+.. function:: prepare_input_source(source[, base])
+
+   This function takes an input source and an optional base URL and returns a fully
+   resolved :class:`InputSource` object ready for reading.  The input source can be
+   given as a string, a file-like object, or an :class:`InputSource` object;
+   parsers will use this function to implement the polymorphic *source* argument to
+   their :meth:`parse` method.
+
diff --git a/Doc/library/xmlrpclib.rst b/Doc/library/xmlrpclib.rst
new file mode 100644
index 0000000..cd507c4
--- /dev/null
+++ b/Doc/library/xmlrpclib.rst
@@ -0,0 +1,422 @@
+
+:mod:`xmlrpclib` --- XML-RPC client access
+==========================================
+
+.. module:: xmlrpclib
+   :synopsis: XML-RPC client access.
+.. moduleauthor:: Fredrik Lundh <fredrik@pythonware.com>
+.. sectionauthor:: Eric S. Raymond <esr@snark.thyrsus.com>
+
+
+.. % Not everything is documented yet.  It might be good to describe
+.. % Marshaller, Unmarshaller, getparser, dumps, loads, and Transport.
+
+.. versionadded:: 2.2
+
+XML-RPC is a Remote Procedure Call method that uses XML passed via HTTP as a
+transport.  With it, a client can call methods with parameters on a remote
+server (the server is named by a URI) and get back structured data.  This module
+supports writing XML-RPC client code; it handles all the details of translating
+between conformable Python objects and XML on the wire.
+
+
+.. class:: ServerProxy(uri[, transport[, encoding[, verbose[,  allow_none[, use_datetime]]]]])
+
+   A :class:`ServerProxy` instance is an object that manages communication with a
+   remote XML-RPC server.  The required first argument is a URI (Uniform Resource
+   Indicator), and will normally be the URL of the server.  The optional second
+   argument is a transport factory instance; by default it is an internal
+   :class:`SafeTransport` instance for https: URLs and an internal HTTP
+   :class:`Transport` instance otherwise.  The optional third argument is an
+   encoding, by default UTF-8. The optional fourth argument is a debugging flag.
+   If *allow_none* is true,  the Python constant ``None`` will be translated into
+   XML; the default behaviour is for ``None`` to raise a :exc:`TypeError`. This is
+   a commonly-used extension to the XML-RPC specification, but isn't supported by
+   all clients and servers; see http://ontosys.com/xml-rpc/extensions.php for a
+   description.  The *use_datetime* flag can be used to cause date/time values to
+   be presented as :class:`datetime.datetime` objects; this is false by default.
+   :class:`datetime.datetime`, :class:`datetime.date` and :class:`datetime.time`
+   objects may be passed to calls.  :class:`datetime.date` objects are converted
+   with a time of "00:00:00". :class:`datetime.time` objects are converted using
+   today's date.
+
+   Both the HTTP and HTTPS transports support the URL syntax extension for HTTP
+   Basic Authentication: ``http://user:pass@host:port/path``.  The  ``user:pass``
+   portion will be base64-encoded as an HTTP 'Authorization' header, and sent to
+   the remote server as part of the connection process when invoking an XML-RPC
+   method.  You only need to use this if the remote server requires a Basic
+   Authentication user and password.
+
+   The returned instance is a proxy object with methods that can be used to invoke
+   corresponding RPC calls on the remote server.  If the remote server supports the
+   introspection API, the proxy can also be used to query the remote server for the
+   methods it supports (service discovery) and fetch other server-associated
+   metadata.
+
+   :class:`ServerProxy` instance methods take Python basic types and objects as
+   arguments and return Python basic types and classes.  Types that are conformable
+   (e.g. that can be marshalled through XML), include the following (and except
+   where noted, they are unmarshalled as the same Python type):
+
+   +---------------------------------+---------------------------------------------+
+   | Name                            | Meaning                                     |
+   +=================================+=============================================+
+   | :const:`boolean`                | The :const:`True` and :const:`False`        |
+   |                                 | constants                                   |
+   +---------------------------------+---------------------------------------------+
+   | :const:`integers`               | Pass in directly                            |
+   +---------------------------------+---------------------------------------------+
+   | :const:`floating-point numbers` | Pass in directly                            |
+   +---------------------------------+---------------------------------------------+
+   | :const:`strings`                | Pass in directly                            |
+   +---------------------------------+---------------------------------------------+
+   | :const:`arrays`                 | Any Python sequence type containing         |
+   |                                 | conformable elements. Arrays are returned   |
+   |                                 | as lists                                    |
+   +---------------------------------+---------------------------------------------+
+   | :const:`structures`             | A Python dictionary. Keys must be strings,  |
+   |                                 | values may be any conformable type. Objects |
+   |                                 | of user-defined classes can be passed in;   |
+   |                                 | only their *__dict__* attribute is          |
+   |                                 | transmitted.                                |
+   +---------------------------------+---------------------------------------------+
+   | :const:`dates`                  | in seconds since the epoch (pass in an      |
+   |                                 | instance of the :class:`DateTime` class) or |
+   |                                 | a :class:`datetime.datetime`,               |
+   |                                 | :class:`datetime.date` or                   |
+   |                                 | :class:`datetime.time` instance             |
+   +---------------------------------+---------------------------------------------+
+   | :const:`binary data`            | pass in an instance of the :class:`Binary`  |
+   |                                 | wrapper class                               |
+   +---------------------------------+---------------------------------------------+
+
+   This is the full set of data types supported by XML-RPC.  Method calls may also
+   raise a special :exc:`Fault` instance, used to signal XML-RPC server errors, or
+   :exc:`ProtocolError` used to signal an error in the HTTP/HTTPS transport layer.
+   Both :exc:`Fault` and :exc:`ProtocolError` derive from a base class called
+   :exc:`Error`.  Note that even though starting with Python 2.2 you can subclass
+   builtin types, the xmlrpclib module currently does not marshal instances of such
+   subclasses.
+
+   When passing strings, characters special to XML such as ``<``, ``>``, and ``&``
+   will be automatically escaped.  However, it's the caller's responsibility to
+   ensure that the string is free of characters that aren't allowed in XML, such as
+   the control characters with ASCII values between 0 and 31 (except, of course,
+   tab, newline and carriage return); failing to do this will result in an XML-RPC
+   request that isn't well-formed XML.  If you have to pass arbitrary strings via
+   XML-RPC, use the :class:`Binary` wrapper class described below.
+
+   :class:`Server` is retained as an alias for :class:`ServerProxy` for backwards
+   compatibility.  New code should use :class:`ServerProxy`.
+
+   .. versionchanged:: 2.5
+      The *use_datetime* flag was added.
+
+   .. versionchanged:: 2.6
+      Instances of new-style classes can be passed in if they have an *__dict__*
+      attribute and don't have a base class that is marshalled in a special way.
+
+
+.. seealso::
+
+   `XML-RPC HOWTO <http://www.tldp.org/HOWTO/XML-RPC-HOWTO/index.html>`_
+      A good description of XML operation and client software in several languages.
+      Contains pretty much everything an XML-RPC client developer needs to know.
+
+   `XML-RPC Hacks page <http://xmlrpc-c.sourceforge.net/hacks.php>`_
+      Extensions for various open-source libraries to support introspection and
+      multicall.
+
+
+.. _serverproxy-objects:
+
+ServerProxy Objects
+-------------------
+
+A :class:`ServerProxy` instance has a method corresponding to each remote
+procedure call accepted by the XML-RPC server.  Calling the method performs an
+RPC, dispatched by both name and argument signature (e.g. the same method name
+can be overloaded with multiple argument signatures).  The RPC finishes by
+returning a value, which may be either returned data in a conformant type or a
+:class:`Fault` or :class:`ProtocolError` object indicating an error.
+
+Servers that support the XML introspection API support some common methods
+grouped under the reserved :attr:`system` member:
+
+
+.. method:: ServerProxy.system.listMethods()
+
+   This method returns a list of strings, one for each (non-system) method
+   supported by the XML-RPC server.
+
+
+.. method:: ServerProxy.system.methodSignature(name)
+
+   This method takes one parameter, the name of a method implemented by the XML-RPC
+   server.It returns an array of possible signatures for this method. A signature
+   is an array of types. The first of these types is the return type of the method,
+   the rest are parameters.
+
+   Because multiple signatures (ie. overloading) is permitted, this method returns
+   a list of signatures rather than a singleton.
+
+   Signatures themselves are restricted to the top level parameters expected by a
+   method. For instance if a method expects one array of structs as a parameter,
+   and it returns a string, its signature is simply "string, array". If it expects
+   three integers and returns a string, its signature is "string, int, int, int".
+
+   If no signature is defined for the method, a non-array value is returned. In
+   Python this means that the type of the returned  value will be something other
+   that list.
+
+
+.. method:: ServerProxy.system.methodHelp(name)
+
+   This method takes one parameter, the name of a method implemented by the XML-RPC
+   server.  It returns a documentation string describing the use of that method. If
+   no such string is available, an empty string is returned. The documentation
+   string may contain HTML markup.
+
+Introspection methods are currently supported by servers written in PHP, C and
+Microsoft .NET. Partial introspection support is included in recent updates to
+UserLand Frontier. Introspection support for Perl, Python and Java is available
+at the `XML-RPC Hacks <http://xmlrpc-c.sourceforge.net/hacks.php>`_ page.
+
+
+.. _boolean-objects:
+
+Boolean Objects
+---------------
+
+This class may be initialized from any Python value; the instance returned
+depends only on its truth value.  It supports various Python operators through
+:meth:`__cmp__`, :meth:`__repr__`, :meth:`__int__`, and :meth:`__bool__`
+methods, all implemented in the obvious ways.
+
+It also has the following method, supported mainly for internal use by the
+unmarshalling code:
+
+
+.. method:: Boolean.encode(out)
+
+   Write the XML-RPC encoding of this Boolean item to the out stream object.
+
+
+.. _datetime-objects:
+
+DateTime Objects
+----------------
+
+This class may be initialized with seconds since the epoch, a time tuple, an ISO
+8601 time/date string, or a :class:`datetime.datetime`, :class:`datetime.date`
+or :class:`datetime.time` instance.  It has the following methods, supported
+mainly for internal use by the marshalling/unmarshalling code:
+
+
+.. method:: DateTime.decode(string)
+
+   Accept a string as the instance's new time value.
+
+
+.. method:: DateTime.encode(out)
+
+   Write the XML-RPC encoding of this :class:`DateTime` item to the *out* stream
+   object.
+
+It also supports certain of Python's built-in operators through  :meth:`__cmp__`
+and :meth:`__repr__` methods.
+
+
+.. _binary-objects:
+
+Binary Objects
+--------------
+
+This class may be initialized from string data (which may include NULs). The
+primary access to the content of a :class:`Binary` object is provided by an
+attribute:
+
+
+.. attribute:: Binary.data
+
+   The binary data encapsulated by the :class:`Binary` instance.  The data is
+   provided as an 8-bit string.
+
+:class:`Binary` objects have the following methods, supported mainly for
+internal use by the marshalling/unmarshalling code:
+
+
+.. method:: Binary.decode(string)
+
+   Accept a base64 string and decode it as the instance's new data.
+
+
+.. method:: Binary.encode(out)
+
+   Write the XML-RPC base 64 encoding of this binary item to the out stream object.
+
+It also supports certain of Python's built-in operators through a
+:meth:`__cmp__` method.
+
+
+.. _fault-objects:
+
+Fault Objects
+-------------
+
+A :class:`Fault` object encapsulates the content of an XML-RPC fault tag. Fault
+objects have the following members:
+
+
+.. attribute:: Fault.faultCode
+
+   A string indicating the fault type.
+
+
+.. attribute:: Fault.faultString
+
+   A string containing a diagnostic message associated with the fault.
+
+
+.. _protocol-error-objects:
+
+ProtocolError Objects
+---------------------
+
+A :class:`ProtocolError` object describes a protocol error in the underlying
+transport layer (such as a 404 'not found' error if the server named by the URI
+does not exist).  It has the following members:
+
+
+.. attribute:: ProtocolError.url
+
+   The URI or URL that triggered the error.
+
+
+.. attribute:: ProtocolError.errcode
+
+   The error code.
+
+
+.. attribute:: ProtocolError.errmsg
+
+   The error message or diagnostic string.
+
+
+.. attribute:: ProtocolError.headers
+
+   A string containing the headers of the HTTP/HTTPS request that triggered the
+   error.
+
+
+MultiCall Objects
+-----------------
+
+.. versionadded:: 2.4
+
+In http://www.xmlrpc.com/discuss/msgReader%241208, an approach is presented to
+encapsulate multiple calls to a remote server into a single request.
+
+
+.. class:: MultiCall(server)
+
+   Create an object used to boxcar method calls. *server* is the eventual target of
+   the call. Calls can be made to the result object, but they will immediately
+   return ``None``, and only store the call name and parameters in the
+   :class:`MultiCall` object. Calling the object itself causes all stored calls to
+   be transmitted as a single ``system.multicall`` request. The result of this call
+   is a generator; iterating over this generator yields the individual results.
+
+A usage example of this class is ::
+
+   multicall = MultiCall(server_proxy)
+   multicall.add(2,3)
+   multicall.get_address("Guido")
+   add_result, address = multicall()
+
+
+Convenience Functions
+---------------------
+
+
+.. function:: boolean(value)
+
+   Convert any Python value to one of the XML-RPC Boolean constants, ``True`` or
+   ``False``.
+
+
+.. function:: dumps(params[, methodname[,  methodresponse[, encoding[, allow_none]]]])
+
+   Convert *params* into an XML-RPC request. or into a response if *methodresponse*
+   is true. *params* can be either a tuple of arguments or an instance of the
+   :exc:`Fault` exception class.  If *methodresponse* is true, only a single value
+   can be returned, meaning that *params* must be of length 1. *encoding*, if
+   supplied, is the encoding to use in the generated XML; the default is UTF-8.
+   Python's :const:`None` value cannot be used in standard XML-RPC; to allow using
+   it via an extension,  provide a true value for *allow_none*.
+
+
+.. function:: loads(data[, use_datetime])
+
+   Convert an XML-RPC request or response into Python objects, a ``(params,
+   methodname)``.  *params* is a tuple of argument; *methodname* is a string, or
+   ``None`` if no method name is present in the packet. If the XML-RPC packet
+   represents a fault condition, this function will raise a :exc:`Fault` exception.
+   The *use_datetime* flag can be used to cause date/time values to be presented as
+   :class:`datetime.datetime` objects; this is false by default. Note that even if
+   you call an XML-RPC method with :class:`datetime.date` or :class:`datetime.time`
+   objects, they are converted to :class:`DateTime` objects internally, so only
+   :class:`datetime.datetime` objects will be returned.
+
+   .. versionchanged:: 2.5
+      The *use_datetime* flag was added.
+
+
+.. _xmlrpc-client-example:
+
+Example of Client Usage
+-----------------------
+
+::
+
+   # simple test program (from the XML-RPC specification)
+   from xmlrpclib import ServerProxy, Error
+
+   # server = ServerProxy("http://localhost:8000") # local server
+   server = ServerProxy("http://betty.userland.com")
+
+   print server
+
+   try:
+       print server.examples.getStateName(41)
+   except Error as v:
+       print "ERROR", v
+
+To access an XML-RPC server through a proxy, you need to define  a custom
+transport.  The following example,  written by NoboNobo, shows how:
+
+.. % fill in original author's name if we ever learn it
+
+.. % Example taken from http://lowlife.jp/nobonobo/wiki/xmlrpcwithproxy.html
+
+::
+
+   import xmlrpclib, httplib
+
+   class ProxiedTransport(xmlrpclib.Transport):
+       def set_proxy(self, proxy):
+           self.proxy = proxy
+       def make_connection(self, host):
+           self.realhost = host
+   	h = httplib.HTTP(self.proxy)
+   	return h
+       def send_request(self, connection, handler, request_body):
+           connection.putrequest("POST", 'http://%s%s' % (self.realhost, handler))
+       def send_host(self, connection, host):
+           connection.putheader('Host', self.realhost)
+
+   p = ProxiedTransport()
+   p.set_proxy('proxy-server:8080')
+   server = xmlrpclib.Server('http://time.xmlrpc.com/RPC2', transport=p)
+   print server.currentTime.getCurrentTime()
+
diff --git a/Doc/library/zipfile.rst b/Doc/library/zipfile.rst
new file mode 100644
index 0000000..5e51bfc
--- /dev/null
+++ b/Doc/library/zipfile.rst
@@ -0,0 +1,408 @@
+
+:mod:`zipfile` --- Work with ZIP archives
+=========================================
+
+.. module:: zipfile
+   :synopsis: Read and write ZIP-format archive files.
+.. moduleauthor:: James C. Ahlstrom <jim@interet.com>
+.. sectionauthor:: James C. Ahlstrom <jim@interet.com>
+
+
+.. % LaTeX markup by Fred L. Drake, Jr. <fdrake@acm.org>
+
+.. versionadded:: 1.6
+
+The ZIP file format is a common archive and compression standard. This module
+provides tools to create, read, write, append, and list a ZIP file.  Any
+advanced use of this module will require an understanding of the format, as
+defined in `PKZIP Application Note
+<http://www.pkware.com/business_and_developers/developer/appnote/>`_.
+
+This module does not currently handle ZIP files which have appended comments, or
+multi-disk ZIP files. It can handle ZIP files that use the ZIP64 extensions
+(that is ZIP files that are more than 4 GByte in size).  It supports decryption
+of encrypted files in ZIP archives, but it cannot currently create an encrypted
+file.
+
+The available attributes of this module are:
+
+
+.. exception:: BadZipfile
+
+   The error raised for bad ZIP files (old name: ``zipfile.error``).
+
+
+.. exception:: LargeZipFile
+
+   The error raised when a ZIP file would require ZIP64 functionality but that has
+   not been enabled.
+
+
+.. class:: ZipFile
+
+   The class for reading and writing ZIP files.  See section
+   :ref:`zipfile-objects` for constructor details.
+
+
+.. class:: PyZipFile
+
+   Class for creating ZIP archives containing Python libraries.
+
+
+.. class:: ZipInfo([filename[, date_time]])
+
+   Class used to represent information about a member of an archive. Instances
+   of this class are returned by the :meth:`getinfo` and :meth:`infolist`
+   methods of :class:`ZipFile` objects.  Most users of the :mod:`zipfile` module
+   will not need to create these, but only use those created by this
+   module. *filename* should be the full name of the archive member, and
+   *date_time* should be a tuple containing six fields which describe the time
+   of the last modification to the file; the fields are described in section
+   :ref:`zipinfo-objects`.
+
+
+.. function:: is_zipfile(filename)
+
+   Returns ``True`` if *filename* is a valid ZIP file based on its magic number,
+   otherwise returns ``False``.  This module does not currently handle ZIP files
+   which have appended comments.
+
+
+.. data:: ZIP_STORED
+
+   The numeric constant for an uncompressed archive member.
+
+
+.. data:: ZIP_DEFLATED
+
+   The numeric constant for the usual ZIP compression method.  This requires the
+   zlib module.  No other compression methods are currently supported.
+
+
+.. seealso::
+
+   `PKZIP Application Note <http://www.pkware.com/business_and_developers/developer/appnote/>`_
+      Documentation on the ZIP file format by Phil Katz, the creator of the format and
+      algorithms used.
+
+   `Info-ZIP Home Page <http://www.info-zip.org/>`_
+      Information about the Info-ZIP project's ZIP archive programs and development
+      libraries.
+
+
+.. _zipfile-objects:
+
+ZipFile Objects
+---------------
+
+
+.. class:: ZipFile(file[, mode[, compression[, allowZip64]]])
+
+   Open a ZIP file, where *file* can be either a path to a file (a string) or a
+   file-like object.  The *mode* parameter should be ``'r'`` to read an existing
+   file, ``'w'`` to truncate and write a new file, or ``'a'`` to append to an
+   existing file.  If *mode* is ``'a'`` and *file* refers to an existing ZIP file,
+   then additional files are added to it.  If *file* does not refer to a ZIP file,
+   then a new ZIP archive is appended to the file.  This is meant for adding a ZIP
+   archive to another file, such as :file:`python.exe`.  Using ::
+
+      cat myzip.zip >> python.exe
+
+   also works, and at least :program:`WinZip` can read such files. If *mode* is
+   ``a`` and the file does not exist at all, it is created. *compression* is the
+   ZIP compression method to use when writing the archive, and should be
+   :const:`ZIP_STORED` or :const:`ZIP_DEFLATED`; unrecognized values will cause
+   :exc:`RuntimeError` to be raised.  If :const:`ZIP_DEFLATED` is specified but the
+   :mod:`zlib` module is not available, :exc:`RuntimeError` is also raised.  The
+   default is :const:`ZIP_STORED`.  If *allowZip64* is ``True`` zipfile will create
+   ZIP files that use the ZIP64 extensions when the zipfile is larger than 2 GB. If
+   it is  false (the default) :mod:`zipfile` will raise an exception when the ZIP
+   file would require ZIP64 extensions. ZIP64 extensions are disabled by default
+   because the default :program:`zip` and :program:`unzip` commands on Unix (the
+   InfoZIP utilities) don't support these extensions.
+
+   .. versionchanged:: 2.6
+      If the file does not exist, it is created if the mode is 'a'.
+
+
+.. method:: ZipFile.close()
+
+   Close the archive file.  You must call :meth:`close` before exiting your program
+   or essential records will not be written.
+
+
+.. method:: ZipFile.getinfo(name)
+
+   Return a :class:`ZipInfo` object with information about the archive member
+   *name*.  Calling :meth:`getinfo` for a name not currently contained in the
+   archive will raise a :exc:`KeyError`.
+
+
+.. method:: ZipFile.infolist()
+
+   Return a list containing a :class:`ZipInfo` object for each member of the
+   archive.  The objects are in the same order as their entries in the actual ZIP
+   file on disk if an existing archive was opened.
+
+
+.. method:: ZipFile.namelist()
+
+   Return a list of archive members by name.
+
+
+.. method:: ZipFile.open(name[, mode[, pwd]])
+
+   Extract a member from the archive as a file-like object (ZipExtFile). *name* is
+   the name of the file in the archive. The *mode* parameter, if included, must be
+   one of the following: ``'r'`` (the  default), ``'U'``, or ``'rU'``. Choosing
+   ``'U'`` or  ``'rU'`` will enable universal newline support in the read-only
+   object. *pwd* is the password used for encrypted files.  Calling  :meth:`open`
+   on a closed ZipFile will raise a  :exc:`RuntimeError`.
+
+   .. note::
+
+      The file-like object is read-only and provides the following methods:
+      :meth:`read`, :meth:`readline`, :meth:`readlines`, :meth:`__iter__`,
+      :meth:`next`.
+
+   .. note::
+
+      If the ZipFile was created by passing in a file-like object as the  first
+      argument to the constructor, then the object returned by :meth:`open` shares the
+      ZipFile's file pointer.  Under these  circumstances, the object returned by
+      :meth:`open` should not  be used after any additional operations are performed
+      on the  ZipFile object.  If the ZipFile was created by passing in a string (the
+      filename) as the first argument to the constructor, then  :meth:`open` will
+      create a new file object that will be held by the ZipExtFile, allowing it to
+      operate independently of the  ZipFile.
+
+   .. versionadded:: 2.6
+
+
+.. method:: ZipFile.printdir()
+
+   Print a table of contents for the archive to ``sys.stdout``.
+
+
+.. method:: ZipFile.setpassword(pwd)
+
+   Set *pwd* as default password to extract encrypted files.
+
+   .. versionadded:: 2.6
+
+
+.. method:: ZipFile.read(name[, pwd])
+
+   Return the bytes of the file in the archive.  The archive must be open for read
+   or append. *pwd* is the password used for encrypted  files and, if specified, it
+   will override the default password set with :meth:`setpassword`.  Calling
+   :meth:`read` on a closed ZipFile  will raise a :exc:`RuntimeError`.
+
+   .. versionchanged:: 2.6
+      *pwd* was added.
+
+
+.. method:: ZipFile.testzip()
+
+   Read all the files in the archive and check their CRC's and file headers.
+   Return the name of the first bad file, or else return ``None``. Calling
+   :meth:`testzip` on a closed ZipFile will raise a :exc:`RuntimeError`.
+
+
+.. method:: ZipFile.write(filename[, arcname[, compress_type]])
+
+   Write the file named *filename* to the archive, giving it the archive name
+   *arcname* (by default, this will be the same as *filename*, but without a drive
+   letter and with leading path separators removed).  If given, *compress_type*
+   overrides the value given for the *compression* parameter to the constructor for
+   the new entry.  The archive must be open with mode ``'w'`` or ``'a'`` -- calling
+   :meth:`write` on a ZipFile created with mode ``'r'`` will raise a
+   :exc:`RuntimeError`.  Calling  :meth:`write` on a closed ZipFile will raise a
+   :exc:`RuntimeError`.
+
+   .. note::
+
+      There is no official file name encoding for ZIP files. If you have unicode file
+      names, please convert them to byte strings in your desired encoding before
+      passing them to :meth:`write`. WinZip interprets all file names as encoded in
+      CP437, also known as DOS Latin.
+
+   .. note::
+
+      Archive names should be relative to the archive root, that is, they should not
+      start with a path separator.
+
+   .. note::
+
+      If ``arcname`` (or ``filename``, if ``arcname`` is  not given) contains a null
+      byte, the name of the file in the archive will be truncated at the null byte.
+
+
+.. method:: ZipFile.writestr(zinfo_or_arcname, bytes)
+
+   Write the string *bytes* to the archive; *zinfo_or_arcname* is either the file
+   name it will be given in the archive, or a :class:`ZipInfo` instance.  If it's
+   an instance, at least the filename, date, and time must be given.  If it's a
+   name, the date and time is set to the current date and time. The archive must be
+   opened with mode ``'w'`` or ``'a'`` -- calling  :meth:`writestr` on a ZipFile
+   created with mode ``'r'``  will raise a :exc:`RuntimeError`.  Calling
+   :meth:`writestr` on a closed ZipFile will raise a :exc:`RuntimeError`.
+
+The following data attribute is also available:
+
+
+.. attribute:: ZipFile.debug
+
+   The level of debug output to use.  This may be set from ``0`` (the default, no
+   output) to ``3`` (the most output).  Debugging information is written to
+   ``sys.stdout``.
+
+
+.. _pyzipfile-objects:
+
+PyZipFile Objects
+-----------------
+
+The :class:`PyZipFile` constructor takes the same parameters as the
+:class:`ZipFile` constructor.  Instances have one method in addition to those of
+:class:`ZipFile` objects.
+
+
+.. method:: PyZipFile.writepy(pathname[, basename])
+
+   Search for files :file:`\*.py` and add the corresponding file to the archive.
+   The corresponding file is a :file:`\*.pyo` file if available, else a
+   :file:`\*.pyc` file, compiling if necessary.  If the pathname is a file, the
+   filename must end with :file:`.py`, and just the (corresponding
+   :file:`\*.py[co]`) file is added at the top level (no path information).  If the
+   pathname is a file that does not end with :file:`.py`, a :exc:`RuntimeError`
+   will be raised.  If it is a directory, and the directory is not a package
+   directory, then all the files :file:`\*.py[co]` are added at the top level.  If
+   the directory is a package directory, then all :file:`\*.py[co]` are added under
+   the package name as a file path, and if any subdirectories are package
+   directories, all of these are added recursively.  *basename* is intended for
+   internal use only.  The :meth:`writepy` method makes archives with file names
+   like this::
+
+      string.pyc                                # Top level name 
+      test/__init__.pyc                         # Package directory 
+      test/testall.pyc                          # Module test.testall
+      test/bogus/__init__.pyc                   # Subpackage directory 
+      test/bogus/myfile.pyc                     # Submodule test.bogus.myfile
+
+
+.. _zipinfo-objects:
+
+ZipInfo Objects
+---------------
+
+Instances of the :class:`ZipInfo` class are returned by the :meth:`getinfo` and
+:meth:`infolist` methods of :class:`ZipFile` objects.  Each object stores
+information about a single member of the ZIP archive.
+
+Instances have the following attributes:
+
+
+.. attribute:: ZipInfo.filename
+
+   Name of the file in the archive.
+
+
+.. attribute:: ZipInfo.date_time
+
+   The time and date of the last modification to the archive member.  This is a
+   tuple of six values:
+
+   +-------+--------------------------+
+   | Index | Value                    |
+   +=======+==========================+
+   | ``0`` | Year                     |
+   +-------+--------------------------+
+   | ``1`` | Month (one-based)        |
+   +-------+--------------------------+
+   | ``2`` | Day of month (one-based) |
+   +-------+--------------------------+
+   | ``3`` | Hours (zero-based)       |
+   +-------+--------------------------+
+   | ``4`` | Minutes (zero-based)     |
+   +-------+--------------------------+
+   | ``5`` | Seconds (zero-based)     |
+   +-------+--------------------------+
+
+
+.. attribute:: ZipInfo.compress_type
+
+   Type of compression for the archive member.
+
+
+.. attribute:: ZipInfo.comment
+
+   Comment for the individual archive member.
+
+
+.. attribute:: ZipInfo.extra
+
+   Expansion field data.  The `PKZIP Application Note
+   <http://www.pkware.com/business_and_developers/developer/appnote/>`_ contains
+   some comments on the internal structure of the data contained in this string.
+
+
+.. attribute:: ZipInfo.create_system
+
+   System which created ZIP archive.
+
+
+.. attribute:: ZipInfo.create_version
+
+   PKZIP version which created ZIP archive.
+
+
+.. attribute:: ZipInfo.extract_version
+
+   PKZIP version needed to extract archive.
+
+
+.. attribute:: ZipInfo.reserved
+
+   Must be zero.
+
+
+.. attribute:: ZipInfo.flag_bits
+
+   ZIP flag bits.
+
+
+.. attribute:: ZipInfo.volume
+
+   Volume number of file header.
+
+
+.. attribute:: ZipInfo.internal_attr
+
+   Internal attributes.
+
+
+.. attribute:: ZipInfo.external_attr
+
+   External file attributes.
+
+
+.. attribute:: ZipInfo.header_offset
+
+   Byte offset to the file header.
+
+
+.. attribute:: ZipInfo.CRC
+
+   CRC-32 of the uncompressed file.
+
+
+.. attribute:: ZipInfo.compress_size
+
+   Size of the compressed data.
+
+
+.. attribute:: ZipInfo.file_size
+
+   Size of the uncompressed file.
+
diff --git a/Doc/library/zipimport.rst b/Doc/library/zipimport.rst
new file mode 100644
index 0000000..f2b2358
--- /dev/null
+++ b/Doc/library/zipimport.rst
@@ -0,0 +1,137 @@
+
+:mod:`zipimport` --- Import modules from Zip archives
+=====================================================
+
+.. module:: zipimport
+   :synopsis: support for importing Python modules from ZIP archives.
+.. moduleauthor:: Just van Rossum <just@letterror.com>
+
+
+.. versionadded:: 2.3
+
+This module adds the ability to import Python modules (:file:`\*.py`,
+:file:`\*.py[co]`) and packages from ZIP-format archives. It is usually not
+needed to use the :mod:`zipimport` module explicitly; it is automatically used
+by the builtin :keyword:`import` mechanism for ``sys.path`` items that are paths
+to ZIP archives.
+
+Typically, ``sys.path`` is a list of directory names as strings.  This module
+also allows an item of ``sys.path`` to be a string naming a ZIP file archive.
+The ZIP archive can contain a subdirectory structure to support package imports,
+and a path within the archive can be specified to only import from a
+subdirectory.  For example, the path :file:`/tmp/example.zip/lib/` would only
+import from the :file:`lib/` subdirectory within the archive.
+
+Any files may be present in the ZIP archive, but only files :file:`.py` and
+:file:`.py[co]` are available for import.  ZIP import of dynamic modules
+(:file:`.pyd`, :file:`.so`) is disallowed. Note that if an archive only contains
+:file:`.py` files, Python will not attempt to modify the archive by adding the
+corresponding :file:`.pyc` or :file:`.pyo` file, meaning that if a ZIP archive
+doesn't contain :file:`.pyc` files, importing may be rather slow.
+
+The available attributes of this module are:
+
+
+.. exception:: ZipImportError
+
+   Exception raised by zipimporter objects. It's a subclass of :exc:`ImportError`,
+   so it can be caught as :exc:`ImportError`, too.
+
+
+.. class:: zipimporter
+
+   The class for importing ZIP files.  See section :ref:`zipimporter-objects`
+   for constructor details.
+
+
+.. seealso::
+
+   `PKZIP Application Note <http://www.pkware.com/business_and_developers/developer/appnote/>`_
+      Documentation on the ZIP file format by Phil Katz, the creator of the format and
+      algorithms used.
+
+   :pep:`0273` - Import Modules from Zip Archives
+      Written by James C. Ahlstrom, who also provided an implementation. Python 2.3
+      follows the specification in PEP 273, but uses an implementation written by Just
+      van Rossum that uses the import hooks described in PEP 302.
+
+   :pep:`0302` - New Import Hooks
+      The PEP to add the import hooks that help this module work.
+
+
+.. _zipimporter-objects:
+
+zipimporter Objects
+-------------------
+
+
+.. class:: zipimporter(archivepath)
+
+   Create a new zipimporter instance. *archivepath* must be a path to a zipfile.
+   :exc:`ZipImportError` is raised if *archivepath* doesn't point to a valid ZIP
+   archive.
+
+
+.. method:: zipimporter.find_module(fullname[, path])
+
+   Search for a module specified by *fullname*. *fullname* must be the fully
+   qualified (dotted) module name. It returns the zipimporter instance itself if
+   the module was found, or :const:`None` if it wasn't. The optional *path*
+   argument is ignored---it's there for  compatibility with the importer protocol.
+
+
+.. method:: zipimporter.get_code(fullname)
+
+   Return the code object for the specified module. Raise :exc:`ZipImportError` if
+   the module couldn't be found.
+
+
+.. method:: zipimporter.get_data(pathname)
+
+   Return the data associated with *pathname*. Raise :exc:`IOError` if the file
+   wasn't found.
+
+
+.. method:: zipimporter.get_source(fullname)
+
+   Return the source code for the specified module. Raise :exc:`ZipImportError` if
+   the module couldn't be found, return :const:`None` if the archive does contain
+   the module, but has no source for it.
+
+
+.. method:: zipimporter.is_package(fullname)
+
+   Return True if the module specified by *fullname* is a package. Raise
+   :exc:`ZipImportError` if the module couldn't be found.
+
+
+.. method:: zipimporter.load_module(fullname)
+
+   Load the module specified by *fullname*. *fullname* must be the fully qualified
+   (dotted) module name. It returns the imported module, or raises
+   :exc:`ZipImportError` if it wasn't found.
+
+
+Examples
+--------
+
+.. _zipimport-examples:
+
+Here is an example that imports a module from a ZIP archive - note that the
+:mod:`zipimport` module is not explicitly used. ::
+
+   $ unzip -l /tmp/example.zip
+   Archive:  /tmp/example.zip
+     Length     Date   Time    Name
+    --------    ----   ----    ----
+        8467  11-26-02 22:30   jwzthreading.py
+    --------                   -------
+        8467                   1 file
+   $ ./python
+   Python 2.3 (#1, Aug 1 2003, 19:54:32) 
+   >>> import sys
+   >>> sys.path.insert(0, '/tmp/example.zip')  # Add .zip file to front of path
+   >>> import jwzthreading
+   >>> jwzthreading.__file__
+   '/tmp/example.zip/jwzthreading.py'
+
diff --git a/Doc/library/zlib.rst b/Doc/library/zlib.rst
new file mode 100644
index 0000000..e57a156
--- /dev/null
+++ b/Doc/library/zlib.rst
@@ -0,0 +1,209 @@
+
+:mod:`zlib` --- Compression compatible with :program:`gzip`
+===========================================================
+
+.. module:: zlib
+   :synopsis: Low-level interface to compression and decompression routines compatible with
+              gzip.
+
+
+For applications that require data compression, the functions in this module
+allow compression and decompression, using the zlib library. The zlib library
+has its own home page at http://www.zlib.net.   There are known
+incompatibilities between the Python module and versions of the zlib library
+earlier than 1.1.3; 1.1.3 has a security vulnerability, so we recommend using
+1.1.4 or later.
+
+zlib's functions have many options and often need to be used in a particular
+order.  This documentation doesn't attempt to cover all of the permutations;
+consult the zlib manual at http://www.zlib.net/manual.html for authoritative
+information.
+
+The available exception and functions in this module are:
+
+
+.. exception:: error
+
+   Exception raised on compression and decompression errors.
+
+
+.. function:: adler32(string[, value])
+
+   Computes a Adler-32 checksum of *string*.  (An Adler-32 checksum is almost as
+   reliable as a CRC32 but can be computed much more quickly.)  If *value* is
+   present, it is used as the starting value of the checksum; otherwise, a fixed
+   default value is used.  This allows computing a running checksum over the
+   concatenation of several input strings.  The algorithm is not cryptographically
+   strong, and should not be used for authentication or digital signatures.  Since
+   the algorithm is designed for use as a checksum algorithm, it is not suitable
+   for use as a general hash algorithm.
+
+
+.. function:: compress(string[, level])
+
+   Compresses the data in *string*, returning a string contained compressed data.
+   *level* is an integer from ``1`` to ``9`` controlling the level of compression;
+   ``1`` is fastest and produces the least compression, ``9`` is slowest and
+   produces the most.  The default value is ``6``.  Raises the :exc:`error`
+   exception if any error occurs.
+
+
+.. function:: compressobj([level])
+
+   Returns a compression object, to be used for compressing data streams that won't
+   fit into memory at once.  *level* is an integer from ``1`` to ``9`` controlling
+   the level of compression; ``1`` is fastest and produces the least compression,
+   ``9`` is slowest and produces the most.  The default value is ``6``.
+
+
+.. function:: crc32(string[, value])
+
+   .. index::
+      single: Cyclic Redundancy Check
+      single: checksum; Cyclic Redundancy Check
+
+   Computes a CRC (Cyclic Redundancy Check)  checksum of *string*. If *value* is
+   present, it is used as the starting value of the checksum; otherwise, a fixed
+   default value is used.  This allows computing a running checksum over the
+   concatenation of several input strings.  The algorithm is not cryptographically
+   strong, and should not be used for authentication or digital signatures.  Since
+   the algorithm is designed for use as a checksum algorithm, it is not suitable
+   for use as a general hash algorithm.
+
+   .. % 
+
+
+.. function:: decompress(string[, wbits[, bufsize]])
+
+   Decompresses the data in *string*, returning a string containing the
+   uncompressed data.  The *wbits* parameter controls the size of the window
+   buffer.  If *bufsize* is given, it is used as the initial size of the output
+   buffer.  Raises the :exc:`error` exception if any error occurs.
+
+   The absolute value of *wbits* is the base two logarithm of the size of the
+   history buffer (the "window size") used when compressing data.  Its absolute
+   value should be between 8 and 15 for the most recent versions of the zlib
+   library, larger values resulting in better compression at the expense of greater
+   memory usage.  The default value is 15.  When *wbits* is negative, the standard
+   :program:`gzip` header is suppressed; this is an undocumented feature of the
+   zlib library, used for compatibility with :program:`unzip`'s compression file
+   format.
+
+   *bufsize* is the initial size of the buffer used to hold decompressed data.  If
+   more space is required, the buffer size will be increased as needed, so you
+   don't have to get this value exactly right; tuning it will only save a few calls
+   to :cfunc:`malloc`.  The default size is 16384.
+
+
+.. function:: decompressobj([wbits])
+
+   Returns a decompression object, to be used for decompressing data streams that
+   won't fit into memory at once.  The *wbits* parameter controls the size of the
+   window buffer.
+
+Compression objects support the following methods:
+
+
+.. method:: Compress.compress(string)
+
+   Compress *string*, returning a string containing compressed data for at least
+   part of the data in *string*.  This data should be concatenated to the output
+   produced by any preceding calls to the :meth:`compress` method.  Some input may
+   be kept in internal buffers for later processing.
+
+
+.. method:: Compress.flush([mode])
+
+   All pending input is processed, and a string containing the remaining compressed
+   output is returned.  *mode* can be selected from the constants
+   :const:`Z_SYNC_FLUSH`,  :const:`Z_FULL_FLUSH`,  or  :const:`Z_FINISH`,
+   defaulting to :const:`Z_FINISH`.  :const:`Z_SYNC_FLUSH` and
+   :const:`Z_FULL_FLUSH` allow compressing further strings of data, while
+   :const:`Z_FINISH` finishes the compressed stream and  prevents compressing any
+   more data.  After calling :meth:`flush` with *mode* set to :const:`Z_FINISH`,
+   the :meth:`compress` method cannot be called again; the only realistic action is
+   to delete the object.
+
+
+.. method:: Compress.copy()
+
+   Returns a copy of the compression object.  This can be used to efficiently
+   compress a set of data that share a common initial prefix.
+
+   .. versionadded:: 2.5
+
+Decompression objects support the following methods, and two attributes:
+
+
+.. attribute:: Decompress.unused_data
+
+   A string which contains any bytes past the end of the compressed data. That is,
+   this remains ``""`` until the last byte that contains compression data is
+   available.  If the whole string turned out to contain compressed data, this is
+   ``""``, the empty string.
+
+   The only way to determine where a string of compressed data ends is by actually
+   decompressing it.  This means that when compressed data is contained part of a
+   larger file, you can only find the end of it by reading data and feeding it
+   followed by some non-empty string into a decompression object's
+   :meth:`decompress` method until the :attr:`unused_data` attribute is no longer
+   the empty string.
+
+
+.. attribute:: Decompress.unconsumed_tail
+
+   A string that contains any data that was not consumed by the last
+   :meth:`decompress` call because it exceeded the limit for the uncompressed data
+   buffer.  This data has not yet been seen by the zlib machinery, so you must feed
+   it (possibly with further data concatenated to it) back to a subsequent
+   :meth:`decompress` method call in order to get correct output.
+
+
+.. method:: Decompress.decompress(string[, max_length])
+
+   Decompress *string*, returning a string containing the uncompressed data
+   corresponding to at least part of the data in *string*.  This data should be
+   concatenated to the output produced by any preceding calls to the
+   :meth:`decompress` method.  Some of the input data may be preserved in internal
+   buffers for later processing.
+
+   If the optional parameter *max_length* is supplied then the return value will be
+   no longer than *max_length*. This may mean that not all of the compressed input
+   can be processed; and unconsumed data will be stored in the attribute
+   :attr:`unconsumed_tail`. This string must be passed to a subsequent call to
+   :meth:`decompress` if decompression is to continue.  If *max_length* is not
+   supplied then the whole input is decompressed, and :attr:`unconsumed_tail` is an
+   empty string.
+
+
+.. method:: Decompress.flush([length])
+
+   All pending input is processed, and a string containing the remaining
+   uncompressed output is returned.  After calling :meth:`flush`, the
+   :meth:`decompress` method cannot be called again; the only realistic action is
+   to delete the object.
+
+   The optional parameter *length* sets the initial size of the output buffer.
+
+
+.. method:: Decompress.copy()
+
+   Returns a copy of the decompression object.  This can be used to save the state
+   of the decompressor midway through the data stream in order to speed up random
+   seeks into the stream at a future point.
+
+   .. versionadded:: 2.5
+
+
+.. seealso::
+
+   Module :mod:`gzip`
+      Reading and writing :program:`gzip`\ -format files.
+
+   http://www.zlib.net
+      The zlib library home page.
+
+   http://www.zlib.net/manual.html
+      The zlib manual explains  the semantics and usage of the library's many
+      functions.
+
diff --git a/Doc/license.rst b/Doc/license.rst
new file mode 100644
index 0000000..a9165f4
--- /dev/null
+++ b/Doc/license.rst
@@ -0,0 +1,647 @@
+.. highlightlang:: none
+
+.. _history-and-license:
+
+*******************
+History and License
+*******************
+
+
+History of the software
+=======================
+
+Python was created in the early 1990s by Guido van Rossum at Stichting
+Mathematisch Centrum (CWI, see http://www.cwi.nl/) in the Netherlands as a
+successor of a language called ABC.  Guido remains Python's principal author,
+although it includes many contributions from others.
+
+In 1995, Guido continued his work on Python at the Corporation for National
+Research Initiatives (CNRI, see http://www.cnri.reston.va.us/) in Reston,
+Virginia where he released several versions of the software.
+
+In May 2000, Guido and the Python core development team moved to BeOpen.com to
+form the BeOpen PythonLabs team.  In October of the same year, the PythonLabs
+team moved to Digital Creations (now Zope Corporation; see
+http://www.zope.com/).  In 2001, the Python Software Foundation (PSF, see
+http://www.python.org/psf/) was formed, a non-profit organization created
+specifically to own Python-related Intellectual Property.  Zope Corporation is a
+sponsoring member of the PSF.
+
+All Python releases are Open Source (see http://www.opensource.org/ for the Open
+Source Definition). Historically, most, but not all, Python releases have also
+been GPL-compatible; the table below summarizes the various releases.
+
++----------------+--------------+-----------+------------+-----------------+
+| Release        | Derived from | Year      | Owner      | GPL compatible? |
++================+==============+===========+============+=================+
+| 0.9.0 thru 1.2 | n/a          | 1991-1995 | CWI        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 1.3 thru 1.5.2 | 1.2          | 1995-1999 | CNRI       | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 1.6            | 1.5.2        | 2000      | CNRI       | no              |
++----------------+--------------+-----------+------------+-----------------+
+| 2.0            | 1.6          | 2000      | BeOpen.com | no              |
++----------------+--------------+-----------+------------+-----------------+
+| 1.6.1          | 1.6          | 2001      | CNRI       | no              |
++----------------+--------------+-----------+------------+-----------------+
+| 2.1            | 2.0+1.6.1    | 2001      | PSF        | no              |
++----------------+--------------+-----------+------------+-----------------+
+| 2.0.1          | 2.0+1.6.1    | 2001      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.1.1          | 2.1+2.0.1    | 2001      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.2            | 2.1.1        | 2001      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.1.2          | 2.1.1        | 2002      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.1.3          | 2.1.2        | 2002      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.2.1          | 2.2          | 2002      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.2.2          | 2.2.1        | 2002      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.2.3          | 2.2.2        | 2002-2003 | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.3            | 2.2.2        | 2002-2003 | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.3.1          | 2.3          | 2002-2003 | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.3.2          | 2.3.1        | 2003      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.3.3          | 2.3.2        | 2003      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.3.4          | 2.3.3        | 2004      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.3.5          | 2.3.4        | 2005      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.4            | 2.3          | 2004      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.4.1          | 2.4          | 2005      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.4.2          | 2.4.1        | 2005      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.4.3          | 2.4.2        | 2006      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.4.4          | 2.4.3        | 2006      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.5            | 2.4          | 2006      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+| 2.5.1          | 2.5          | 2007      | PSF        | yes             |
++----------------+--------------+-----------+------------+-----------------+
+
+.. note::
+
+   GPL-compatible doesn't mean that we're distributing Python under the GPL.  All
+   Python licenses, unlike the GPL, let you distribute a modified version without
+   making your changes open source. The GPL-compatible licenses make it possible to
+   combine Python with other software that is released under the GPL; the others
+   don't.
+
+Thanks to the many outside volunteers who have worked under Guido's direction to
+make these releases possible.
+
+
+Terms and conditions for accessing or otherwise using Python
+============================================================
+
+
+.. centered:: PSF LICENSE AGREEMENT FOR PYTHON |release|
+
+#. This LICENSE AGREEMENT is between the Python Software Foundation ("PSF"), and
+   the Individual or Organization ("Licensee") accessing and otherwise using Python
+   |release| software in source or binary form and its associated documentation.
+
+#. Subject to the terms and conditions of this License Agreement, PSF hereby
+   grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,
+   analyze, test, perform and/or display publicly, prepare derivative works,
+   distribute, and otherwise use Python |release| alone or in any derivative
+   version, provided, however, that PSF's License Agreement and PSF's notice of
+   copyright, i.e., "Copyright © 2001-2007 Python Software Foundation; All Rights
+   Reserved" are retained in Python |release| alone or in any derivative version
+   prepared by Licensee.
+
+#. In the event Licensee prepares a derivative work that is based on or
+   incorporates Python |release| or any part thereof, and wants to make the
+   derivative work available to others as provided herein, then Licensee hereby
+   agrees to include in any such work a brief summary of the changes made to Python
+   |release|.
+
+#. PSF is making Python |release| available to Licensee on an "AS IS" basis.
+   PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  BY WAY OF
+   EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND DISCLAIMS ANY REPRESENTATION OR
+   WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE
+   USE OF PYTHON |release| WILL NOT INFRINGE ANY THIRD PARTY RIGHTS.
+
+#. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON |release|
+   FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS A RESULT OF
+   MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON |release|, OR ANY DERIVATIVE
+   THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
+
+#. This License Agreement will automatically terminate upon a material breach of
+   its terms and conditions.
+
+#. Nothing in this License Agreement shall be deemed to create any relationship
+   of agency, partnership, or joint venture between PSF and Licensee.  This License
+   Agreement does not grant permission to use PSF trademarks or trade name in a
+   trademark sense to endorse or promote products or services of Licensee, or any
+   third party.
+
+#. By copying, installing or otherwise using Python |release|, Licensee agrees
+   to be bound by the terms and conditions of this License Agreement.
+
+
+.. centered:: BEOPEN.COM LICENSE AGREEMENT FOR PYTHON 2.0
+
+
+.. centered:: BEOPEN PYTHON OPEN SOURCE LICENSE AGREEMENT VERSION 1
+
+#. This LICENSE AGREEMENT is between BeOpen.com ("BeOpen"), having an office at
+   160 Saratoga Avenue, Santa Clara, CA 95051, and the Individual or Organization
+   ("Licensee") accessing and otherwise using this software in source or binary
+   form and its associated documentation ("the Software").
+
+#. Subject to the terms and conditions of this BeOpen Python License Agreement,
+   BeOpen hereby grants Licensee a non-exclusive, royalty-free, world-wide license
+   to reproduce, analyze, test, perform and/or display publicly, prepare derivative
+   works, distribute, and otherwise use the Software alone or in any derivative
+   version, provided, however, that the BeOpen Python License is retained in the
+   Software, alone or in any derivative version prepared by Licensee.
+
+#. BeOpen is making the Software available to Licensee on an "AS IS" basis.
+   BEOPEN MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  BY WAY OF
+   EXAMPLE, BUT NOT LIMITATION, BEOPEN MAKES NO AND DISCLAIMS ANY REPRESENTATION OR
+   WARRANTY OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE
+   USE OF THE SOFTWARE WILL NOT INFRINGE ANY THIRD PARTY RIGHTS.
+
+#. BEOPEN SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF THE SOFTWARE FOR
+   ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS A RESULT OF USING,
+   MODIFYING OR DISTRIBUTING THE SOFTWARE, OR ANY DERIVATIVE THEREOF, EVEN IF
+   ADVISED OF THE POSSIBILITY THEREOF.
+
+#. This License Agreement will automatically terminate upon a material breach of
+   its terms and conditions.
+
+#. This License Agreement shall be governed by and interpreted in all respects
+   by the law of the State of California, excluding conflict of law provisions.
+   Nothing in this License Agreement shall be deemed to create any relationship of
+   agency, partnership, or joint venture between BeOpen and Licensee.  This License
+   Agreement does not grant permission to use BeOpen trademarks or trade names in a
+   trademark sense to endorse or promote products or services of Licensee, or any
+   third party.  As an exception, the "BeOpen Python" logos available at
+   http://www.pythonlabs.com/logos.html may be used according to the permissions
+   granted on that web page.
+
+#. By copying, installing or otherwise using the software, Licensee agrees to be
+   bound by the terms and conditions of this License Agreement.
+
+
+.. centered:: CNRI LICENSE AGREEMENT FOR PYTHON 1.6.1
+
+#. This LICENSE AGREEMENT is between the Corporation for National Research
+   Initiatives, having an office at 1895 Preston White Drive, Reston, VA 20191
+   ("CNRI"), and the Individual or Organization ("Licensee") accessing and
+   otherwise using Python 1.6.1 software in source or binary form and its
+   associated documentation.
+
+#. Subject to the terms and conditions of this License Agreement, CNRI hereby
+   grants Licensee a nonexclusive, royalty-free, world-wide license to reproduce,
+   analyze, test, perform and/or display publicly, prepare derivative works,
+   distribute, and otherwise use Python 1.6.1 alone or in any derivative version,
+   provided, however, that CNRI's License Agreement and CNRI's notice of copyright,
+   i.e., "Copyright © 1995-2001 Corporation for National Research Initiatives; All
+   Rights Reserved" are retained in Python 1.6.1 alone or in any derivative version
+   prepared by Licensee.  Alternately, in lieu of CNRI's License Agreement,
+   Licensee may substitute the following text (omitting the quotes): "Python 1.6.1
+   is made available subject to the terms and conditions in CNRI's License
+   Agreement.  This Agreement together with Python 1.6.1 may be located on the
+   Internet using the following unique, persistent identifier (known as a handle):
+   1895.22/1013.  This Agreement may also be obtained from a proxy server on the
+   Internet using the following URL: http://hdl.handle.net/1895.22/1013."
+
+#. In the event Licensee prepares a derivative work that is based on or
+   incorporates Python 1.6.1 or any part thereof, and wants to make the derivative
+   work available to others as provided herein, then Licensee hereby agrees to
+   include in any such work a brief summary of the changes made to Python 1.6.1.
+
+#. CNRI is making Python 1.6.1 available to Licensee on an "AS IS" basis.  CNRI
+   MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.  BY WAY OF EXAMPLE,
+   BUT NOT LIMITATION, CNRI MAKES NO AND DISCLAIMS ANY REPRESENTATION OR WARRANTY
+   OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF
+   PYTHON 1.6.1 WILL NOT INFRINGE ANY THIRD PARTY RIGHTS.
+
+#. CNRI SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON 1.6.1 FOR
+   ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS A RESULT OF
+   MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON 1.6.1, OR ANY DERIVATIVE
+   THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
+
+#. This License Agreement will automatically terminate upon a material breach of
+   its terms and conditions.
+
+#. This License Agreement shall be governed by the federal intellectual property
+   law of the United States, including without limitation the federal copyright
+   law, and, to the extent such U.S. federal law does not apply, by the law of the
+   Commonwealth of Virginia, excluding Virginia's conflict of law provisions.
+   Notwithstanding the foregoing, with regard to derivative works based on Python
+   1.6.1 that incorporate non-separable material that was previously distributed
+   under the GNU General Public License (GPL), the law of the Commonwealth of
+   Virginia shall govern this License Agreement only as to issues arising under or
+   with respect to Paragraphs 4, 5, and 7 of this License Agreement.  Nothing in
+   this License Agreement shall be deemed to create any relationship of agency,
+   partnership, or joint venture between CNRI and Licensee.  This License Agreement
+   does not grant permission to use CNRI trademarks or trade name in a trademark
+   sense to endorse or promote products or services of Licensee, or any third
+   party.
+
+#. By clicking on the "ACCEPT" button where indicated, or by copying, installing
+   or otherwise using Python 1.6.1, Licensee agrees to be bound by the terms and
+   conditions of this License Agreement.
+
+
+.. centered:: ACCEPT
+
+
+.. centered:: CWI LICENSE AGREEMENT FOR PYTHON 0.9.0 THROUGH 1.2
+
+Copyright © 1991 - 1995, Stichting Mathematisch Centrum Amsterdam, The
+Netherlands.  All rights reserved.
+
+Permission to use, copy, modify, and distribute this software and its
+documentation for any purpose and without fee is hereby granted, provided that
+the above copyright notice appear in all copies and that both that copyright
+notice and this permission notice appear in supporting documentation, and that
+the name of Stichting Mathematisch Centrum or CWI not be used in advertising or
+publicity pertaining to distribution of the software without specific, written
+prior permission.
+
+STICHTING MATHEMATISCH CENTRUM DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
+EVENT SHALL STICHTING MATHEMATISCH CENTRUM BE LIABLE FOR ANY SPECIAL, INDIRECT
+OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
+DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
+SOFTWARE.
+
+
+Licenses and Acknowledgements for Incorporated Software
+=======================================================
+
+This section is an incomplete, but growing list of licenses and acknowledgements
+for third-party software incorporated in the Python distribution.
+
+
+Mersenne Twister
+----------------
+
+The :mod:`_random` module includes code based on a download from
+http://www.math.keio.ac.jp/ matumoto/MT2002/emt19937ar.html. The following are
+the verbatim comments from the original code::
+
+   A C-program for MT19937, with initialization improved 2002/1/26.
+   Coded by Takuji Nishimura and Makoto Matsumoto.
+
+   Before using, initialize the state by using init_genrand(seed)
+   or init_by_array(init_key, key_length).
+
+   Copyright (C) 1997 - 2002, Makoto Matsumoto and Takuji Nishimura,
+   All rights reserved.
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions
+   are met:
+
+    1. Redistributions of source code must retain the above copyright
+       notice, this list of conditions and the following disclaimer.
+
+    2. Redistributions in binary form must reproduce the above copyright
+       notice, this list of conditions and the following disclaimer in the
+       documentation and/or other materials provided with the distribution.
+
+    3. The names of its contributors may not be used to endorse or promote
+       products derived from this software without specific prior written
+       permission.
+
+   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
+   Any feedback is very welcome.
+   http://www.math.keio.ac.jp/matumoto/emt.html
+   email: matumoto@math.keio.ac.jp
+
+
+Sockets
+-------
+
+The :mod:`socket` module uses the functions, :func:`getaddrinfo`, and
+:func:`getnameinfo`, which are coded in separate source files from the WIDE
+Project, http://www.wide.ad.jp/about/index.html. ::
+
+   Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
+   All rights reserved.
+
+   Redistribution and use in source and binary forms, with or without
+   modification, are permitted provided that the following conditions
+   are met:
+   1. Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+   2. Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+   3. Neither the name of the project nor the names of its contributors
+      may be used to endorse or promote products derived from this software
+      without specific prior written permission.
+
+   THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
+   GAI_ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+   ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
+   FOR GAI_ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+   OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+   HOWEVER CAUSED AND ON GAI_ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+   LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN GAI_ANY WAY
+   OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+   SUCH DAMAGE.
+
+
+Floating point exception control
+--------------------------------
+
+The source for the :mod:`fpectl` module includes the following notice::
+
+     ---------------------------------------------------------------------  
+    /                       Copyright (c) 1996.                           \ 
+   |          The Regents of the University of California.                 |
+   |                        All rights reserved.                           |
+   |                                                                       |
+   |   Permission to use, copy, modify, and distribute this software for   |
+   |   any purpose without fee is hereby granted, provided that this en-   |
+   |   tire notice is included in all copies of any software which is or   |
+   |   includes  a  copy  or  modification  of  this software and in all   |
+   |   copies of the supporting documentation for such software.           |
+   |                                                                       |
+   |   This  work was produced at the University of California, Lawrence   |
+   |   Livermore National Laboratory under  contract  no.  W-7405-ENG-48   |
+   |   between  the  U.S.  Department  of  Energy and The Regents of the   |
+   |   University of California for the operation of UC LLNL.              |
+   |                                                                       |
+   |                              DISCLAIMER                               |
+   |                                                                       |
+   |   This  software was prepared as an account of work sponsored by an   |
+   |   agency of the United States Government. Neither the United States   |
+   |   Government  nor the University of California nor any of their em-   |
+   |   ployees, makes any warranty, express or implied, or  assumes  any   |
+   |   liability  or  responsibility  for the accuracy, completeness, or   |
+   |   usefulness of any information,  apparatus,  product,  or  process   |
+   |   disclosed,   or  represents  that  its  use  would  not  infringe   |
+   |   privately-owned rights. Reference herein to any specific  commer-   |
+   |   cial  products,  process,  or  service  by trade name, trademark,   |
+   |   manufacturer, or otherwise, does not  necessarily  constitute  or   |
+   |   imply  its endorsement, recommendation, or favoring by the United   |
+   |   States Government or the University of California. The views  and   |
+   |   opinions  of authors expressed herein do not necessarily state or   |
+   |   reflect those of the United States Government or  the  University   |
+   |   of  California,  and shall not be used for advertising or product   |
+    \  endorsement purposes.                                              / 
+     ---------------------------------------------------------------------
+
+
+MD5 message digest algorithm
+----------------------------
+
+The source code for the :mod:`md5` module contains the following notice::
+
+     Copyright (C) 1999, 2002 Aladdin Enterprises.  All rights reserved.
+
+     This software is provided 'as-is', without any express or implied
+     warranty.  In no event will the authors be held liable for any damages
+     arising from the use of this software.
+
+     Permission is granted to anyone to use this software for any purpose,
+     including commercial applications, and to alter it and redistribute it
+     freely, subject to the following restrictions:
+
+     1. The origin of this software must not be misrepresented; you must not
+        claim that you wrote the original software. If you use this software
+        in a product, an acknowledgment in the product documentation would be
+        appreciated but is not required.
+     2. Altered source versions must be plainly marked as such, and must not be
+        misrepresented as being the original software.
+     3. This notice may not be removed or altered from any source distribution.
+
+     L. Peter Deutsch
+     ghost@aladdin.com
+
+     Independent implementation of MD5 (RFC 1321).
+
+     This code implements the MD5 Algorithm defined in RFC 1321, whose
+     text is available at
+   	http://www.ietf.org/rfc/rfc1321.txt
+     The code is derived from the text of the RFC, including the test suite
+     (section A.5) but excluding the rest of Appendix A.  It does not include
+     any code or documentation that is identified in the RFC as being
+     copyrighted.
+
+     The original and principal author of md5.h is L. Peter Deutsch
+     <ghost@aladdin.com>.  Other authors are noted in the change history
+     that follows (in reverse chronological order):
+
+     2002-04-13 lpd Removed support for non-ANSI compilers; removed
+   	references to Ghostscript; clarified derivation from RFC 1321;
+   	now handles byte order either statically or dynamically.
+     1999-11-04 lpd Edited comments slightly for automatic TOC extraction.
+     1999-10-18 lpd Fixed typo in header comment (ansi2knr rather than md5);
+   	added conditionalization for C++ compilation from Martin
+   	Purschke <purschke@bnl.gov>.
+     1999-05-03 lpd Original version.
+
+
+Asynchronous socket services
+----------------------------
+
+The :mod:`asynchat` and :mod:`asyncore` modules contain the following notice::
+
+   Copyright 1996 by Sam Rushing
+
+                           All Rights Reserved
+
+   Permission to use, copy, modify, and distribute this software and
+   its documentation for any purpose and without fee is hereby
+   granted, provided that the above copyright notice appear in all
+   copies and that both that copyright notice and this permission
+   notice appear in supporting documentation, and that the name of Sam
+   Rushing not be used in advertising or publicity pertaining to
+   distribution of the software without specific, written prior
+   permission.
+
+   SAM RUSHING DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
+   INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN
+   NO EVENT SHALL SAM RUSHING BE LIABLE FOR ANY SPECIAL, INDIRECT OR
+   CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
+   OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
+   NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+
+Cookie management
+-----------------
+
+The :mod:`Cookie` module contains the following notice::
+
+   Copyright 2000 by Timothy O'Malley <timo@alum.mit.edu>
+
+                  All Rights Reserved
+
+   Permission to use, copy, modify, and distribute this software
+   and its documentation for any purpose and without fee is hereby
+   granted, provided that the above copyright notice appear in all
+   copies and that both that copyright notice and this permission
+   notice appear in supporting documentation, and that the name of
+   Timothy O'Malley  not be used in advertising or publicity
+   pertaining to distribution of the software without specific, written
+   prior permission.
+
+   Timothy O'Malley DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+   SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+   AND FITNESS, IN NO EVENT SHALL Timothy O'Malley BE LIABLE FOR
+   ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+   WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+   ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+   PERFORMANCE OF THIS SOFTWARE.
+
+
+Profiling
+---------
+
+The :mod:`profile` and :mod:`pstats` modules contain the following notice::
+
+   Copyright 1994, by InfoSeek Corporation, all rights reserved.
+   Written by James Roskind
+
+   Permission to use, copy, modify, and distribute this Python software
+   and its associated documentation for any purpose (subject to the
+   restriction in the following sentence) without fee is hereby granted,
+   provided that the above copyright notice appears in all copies, and
+   that both that copyright notice and this permission notice appear in
+   supporting documentation, and that the name of InfoSeek not be used in
+   advertising or publicity pertaining to distribution of the software
+   without specific, written prior permission.  This permission is
+   explicitly restricted to the copying and modification of the software
+   to remain in Python, compiled Python, or other languages (such as C)
+   wherein the modified or derived code is exclusively imported into a
+   Python module.
+
+   INFOSEEK CORPORATION DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS
+   SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+   FITNESS. IN NO EVENT SHALL INFOSEEK CORPORATION BE LIABLE FOR ANY
+   SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
+   RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF
+   CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+   CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+
+Execution tracing
+-----------------
+
+The :mod:`trace` module contains the following notice::
+
+   portions copyright 2001, Autonomous Zones Industries, Inc., all rights...
+   err...  reserved and offered to the public under the terms of the
+   Python 2.2 license.
+   Author: Zooko O'Whielacronx
+   http://zooko.com/
+   mailto:zooko@zooko.com
+
+   Copyright 2000, Mojam Media, Inc., all rights reserved.
+   Author: Skip Montanaro
+
+   Copyright 1999, Bioreason, Inc., all rights reserved.
+   Author: Andrew Dalke
+
+   Copyright 1995-1997, Automatrix, Inc., all rights reserved.
+   Author: Skip Montanaro
+
+   Copyright 1991-1995, Stichting Mathematisch Centrum, all rights reserved.
+
+
+   Permission to use, copy, modify, and distribute this Python software and
+   its associated documentation for any purpose without fee is hereby
+   granted, provided that the above copyright notice appears in all copies,
+   and that both that copyright notice and this permission notice appear in
+   supporting documentation, and that the name of neither Automatrix,
+   Bioreason or Mojam Media be used in advertising or publicity pertaining to
+   distribution of the software without specific, written prior permission.
+
+
+UUencode and UUdecode functions
+-------------------------------
+
+The :mod:`uu` module contains the following notice::
+
+   Copyright 1994 by Lance Ellinghouse
+   Cathedral City, California Republic, United States of America.
+                          All Rights Reserved
+   Permission to use, copy, modify, and distribute this software and its
+   documentation for any purpose and without fee is hereby granted,
+   provided that the above copyright notice appear in all copies and that
+   both that copyright notice and this permission notice appear in
+   supporting documentation, and that the name of Lance Ellinghouse
+   not be used in advertising or publicity pertaining to distribution
+   of the software without specific, written prior permission.
+   LANCE ELLINGHOUSE DISCLAIMS ALL WARRANTIES WITH REGARD TO
+   THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
+   FITNESS, IN NO EVENT SHALL LANCE ELLINGHOUSE CENTRUM BE LIABLE
+   FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+   WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+   ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+   OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+   Modified by Jack Jansen, CWI, July 1995:
+   - Use binascii module to do the actual line-by-line conversion
+     between ascii and binary. This results in a 1000-fold speedup. The C
+     version is still 5 times faster, though.
+   - Arguments more compliant with python standard
+
+
+XML Remote Procedure Calls
+--------------------------
+
+The :mod:`xmlrpclib` module contains the following notice::
+
+       The XML-RPC client interface is
+
+   Copyright (c) 1999-2002 by Secret Labs AB
+   Copyright (c) 1999-2002 by Fredrik Lundh
+
+   By obtaining, using, and/or copying this software and/or its
+   associated documentation, you agree that you have read, understood,
+   and will comply with the following terms and conditions:
+
+   Permission to use, copy, modify, and distribute this software and
+   its associated documentation for any purpose and without fee is
+   hereby granted, provided that the above copyright notice appears in
+   all copies, and that both that copyright notice and this permission
+   notice appear in supporting documentation, and that the name of
+   Secret Labs AB or the author not be used in advertising or publicity
+   pertaining to distribution of the software without specific, written
+   prior permission.
+
+   SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+   TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
+   ABILITY AND FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
+   BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
+   DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+   WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+   ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+   OF THIS SOFTWARE.
+
diff --git a/Doc/reference/compound_stmts.rst b/Doc/reference/compound_stmts.rst
new file mode 100644
index 0000000..e7587f6
--- /dev/null
+++ b/Doc/reference/compound_stmts.rst
@@ -0,0 +1,554 @@
+
+.. _compound:
+
+*******************
+Compound statements
+*******************
+
+.. index:: pair: compound; statement
+
+Compound statements contain (groups of) other statements; they affect or control
+the execution of those other statements in some way.  In general, compound
+statements span multiple lines, although in simple incarnations a whole compound
+statement may be contained in one line.
+
+The :keyword:`if`, :keyword:`while` and :keyword:`for` statements implement
+traditional control flow constructs.  :keyword:`try` specifies exception
+handlers and/or cleanup code for a group of statements.  Function and class
+definitions are also syntactically compound statements.
+
+.. index::
+   single: clause
+   single: suite
+
+Compound statements consist of one or more 'clauses.'  A clause consists of a
+header and a 'suite.'  The clause headers of a particular compound statement are
+all at the same indentation level. Each clause header begins with a uniquely
+identifying keyword and ends with a colon.  A suite is a group of statements
+controlled by a clause.  A suite can be one or more semicolon-separated simple
+statements on the same line as the header, following the header's colon, or it
+can be one or more indented statements on subsequent lines.  Only the latter
+form of suite can contain nested compound statements; the following is illegal,
+mostly because it wouldn't be clear to which :keyword:`if` clause a following
+:keyword:`else` clause would belong:   ::
+
+   if test1: if test2: print x
+
+Also note that the semicolon binds tighter than the colon in this context, so
+that in the following example, either all or none of the :keyword:`print`
+statements are executed::
+
+   if x < y < z: print x; print y; print z
+
+Summarizing:
+
+.. productionlist::
+   compound_stmt: `if_stmt`
+                : | `while_stmt`
+                : | `for_stmt`
+                : | `try_stmt`
+                : | `with_stmt`
+                : | `funcdef`
+                : | `classdef`
+   suite: `stmt_list` NEWLINE | NEWLINE INDENT `statement`+ DEDENT
+   statement: `stmt_list` NEWLINE | `compound_stmt`
+   stmt_list: `simple_stmt` (";" `simple_stmt`)* [";"]
+
+.. index::
+   single: NEWLINE token
+   single: DEDENT token
+   pair: dangling; else
+
+Note that statements always end in a ``NEWLINE`` possibly followed by a
+``DEDENT``. Also note that optional continuation clauses always begin with a
+keyword that cannot start a statement, thus there are no ambiguities (the
+'dangling :keyword:`else`' problem is solved in Python by requiring nested
+:keyword:`if` statements to be indented).
+
+The formatting of the grammar rules in the following sections places each clause
+on a separate line for clarity.
+
+
+.. _if:
+
+The :keyword:`if` statement
+===========================
+
+.. index:: statement: if
+
+The :keyword:`if` statement is used for conditional execution:
+
+.. productionlist::
+   if_stmt: "if" `expression` ":" `suite`
+          : ( "elif" `expression` ":" `suite` )*
+          : ["else" ":" `suite`]
+
+.. index::
+   keyword: elif
+   keyword: else
+
+It selects exactly one of the suites by evaluating the expressions one by one
+until one is found to be true (see section :ref:`booleans` for the definition of
+true and false); then that suite is executed (and no other part of the
+:keyword:`if` statement is executed or evaluated).  If all expressions are
+false, the suite of the :keyword:`else` clause, if present, is executed.
+
+
+.. _while:
+
+The :keyword:`while` statement
+==============================
+
+.. index::
+   statement: while
+   pair: loop; statement
+
+The :keyword:`while` statement is used for repeated execution as long as an
+expression is true:
+
+.. productionlist::
+   while_stmt: "while" `expression` ":" `suite`
+             : ["else" ":" `suite`]
+
+.. index:: keyword: else
+
+This repeatedly tests the expression and, if it is true, executes the first
+suite; if the expression is false (which may be the first time it is tested) the
+suite of the :keyword:`else` clause, if present, is executed and the loop
+terminates.
+
+.. index::
+   statement: break
+   statement: continue
+
+A :keyword:`break` statement executed in the first suite terminates the loop
+without executing the :keyword:`else` clause's suite.  A :keyword:`continue`
+statement executed in the first suite skips the rest of the suite and goes back
+to testing the expression.
+
+
+.. _for:
+
+The :keyword:`for` statement
+============================
+
+.. index::
+   statement: for
+   pair: loop; statement
+
+.. index:: object: sequence
+
+The :keyword:`for` statement is used to iterate over the elements of a sequence
+(such as a string, tuple or list) or other iterable object:
+
+.. productionlist::
+   for_stmt: "for" `target_list` "in" `expression_list` ":" `suite`
+           : ["else" ":" `suite`]
+
+.. index::
+   keyword: in
+   keyword: else
+   pair: target; list
+
+The expression list is evaluated once; it should yield an iterable object.  An
+iterator is created for the result of the ``expression_list``.  The suite is
+then executed once for each item provided by the iterator, in the order of
+ascending indices.  Each item in turn is assigned to the target list using the
+standard rules for assignments, and then the suite is executed.  When the items
+are exhausted (which is immediately when the sequence is empty), the suite in
+the :keyword:`else` clause, if present, is executed, and the loop terminates.
+
+.. index::
+   statement: break
+   statement: continue
+
+A :keyword:`break` statement executed in the first suite terminates the loop
+without executing the :keyword:`else` clause's suite.  A :keyword:`continue`
+statement executed in the first suite skips the rest of the suite and continues
+with the next item, or with the :keyword:`else` clause if there was no next
+item.
+
+The suite may assign to the variable(s) in the target list; this does not affect
+the next item assigned to it.
+
+.. index::
+   builtin: range
+   pair: Pascal; language
+
+The target list is not deleted when the loop is finished, but if the sequence is
+empty, it will not have been assigned to at all by the loop.  Hint: the built-in
+function :func:`range` returns a sequence of integers suitable to emulate the
+effect of Pascal's ``for i := a to b do``; e.g., ``range(3)`` returns the list
+``[0, 1, 2]``.
+
+.. warning::
+
+   .. index::
+      single: loop; over mutable sequence
+      single: mutable sequence; loop over
+
+   There is a subtlety when the sequence is being modified by the loop (this can
+   only occur for mutable sequences, i.e. lists). An internal counter is used to
+   keep track of which item is used next, and this is incremented on each
+   iteration.  When this counter has reached the length of the sequence the loop
+   terminates.  This means that if the suite deletes the current (or a previous)
+   item from the sequence, the next item will be skipped (since it gets the index
+   of the current item which has already been treated).  Likewise, if the suite
+   inserts an item in the sequence before the current item, the current item will
+   be treated again the next time through the loop. This can lead to nasty bugs
+   that can be avoided by making a temporary copy using a slice of the whole
+   sequence, e.g.,
+
+::
+
+   for x in a[:]:
+       if x < 0: a.remove(x)
+
+
+.. _try:
+
+The :keyword:`try` statement
+============================
+
+.. index:: statement: try
+
+The :keyword:`try` statement specifies exception handlers and/or cleanup code
+for a group of statements:
+
+.. productionlist::
+   try_stmt: try1_stmt | try2_stmt
+   try1_stmt: "try" ":" `suite`
+            : ("except" [`expression` ["," `target`]] ":" `suite`)+
+            : ["else" ":" `suite`]
+            : ["finally" ":" `suite`]
+   try2_stmt: "try" ":" `suite`
+            : "finally" ":" `suite`
+
+.. versionchanged:: 2.5
+   In previous versions of Python, :keyword:`try`...\ :keyword:`except`...\
+   :keyword:`finally` did not work. :keyword:`try`...\ :keyword:`except` had to be
+   nested in :keyword:`try`...\ :keyword:`finally`.
+
+.. index:: keyword: except
+
+The :keyword:`except` clause(s) specify one or more exception handlers. When no
+exception occurs in the :keyword:`try` clause, no exception handler is executed.
+When an exception occurs in the :keyword:`try` suite, a search for an exception
+handler is started.  This search inspects the except clauses in turn until one
+is found that matches the exception.  An expression-less except clause, if
+present, must be last; it matches any exception.  For an except clause with an
+expression, that expression is evaluated, and the clause matches the exception
+if the resulting object is "compatible" with the exception.  An object is
+compatible with an exception if it is the class or a base class of the exception
+object or a tuple containing an item compatible with the exception.
+
+If no except clause matches the exception, the search for an exception handler
+continues in the surrounding code and on the invocation stack.  [#]_
+
+If the evaluation of an expression in the header of an except clause raises an
+exception, the original search for a handler is canceled and a search starts for
+the new exception in the surrounding code and on the call stack (it is treated
+as if the entire :keyword:`try` statement raised the exception).
+
+When a matching except clause is found, the exception is assigned to the target
+specified in that except clause, if present, and the except clause's suite is
+executed.  All except clauses must have an executable block.  When the end of
+this block is reached, execution continues normally after the entire try
+statement.  (This means that if two nested handlers exist for the same
+exception, and the exception occurs in the try clause of the inner handler, the
+outer handler will not handle the exception.)
+
+.. index::
+   module: sys
+   object: traceback
+
+Before an except clause's suite is executed, details about the exception are
+stored in the :mod:`sys` module and can be access via :func:`sys.exc_info`.
+:func:`sys.exc_info` returns a 3-tuple consisting of: ``exc_type`` receives the
+object identifying the exception; ``exc_value`` receives the exception's
+parameter; ``exc_traceback`` receives a traceback object (see section
+:ref:`types`) identifying the point in the program where the exception
+occurred. :func:`sys.exc_info` values are restored to their previous values
+(before the call) when returning from a function that handled an exception.
+
+.. index::
+   keyword: else
+   statement: return
+   statement: break
+   statement: continue
+
+The optional :keyword:`else` clause is executed if and when control flows off
+the end of the :keyword:`try` clause. [#]_ Exceptions in the :keyword:`else`
+clause are not handled by the preceding :keyword:`except` clauses.
+
+.. index:: keyword: finally
+
+If :keyword:`finally` is present, it specifies a 'cleanup' handler.  The
+:keyword:`try` clause is executed, including any :keyword:`except` and
+:keyword:`else` clauses.  If an exception occurs in any of the clauses and is
+not handled, the exception is temporarily saved. The :keyword:`finally` clause
+is executed.  If there is a saved exception, it is re-raised at the end of the
+:keyword:`finally` clause. If the :keyword:`finally` clause raises another
+exception or executes a :keyword:`return` or :keyword:`break` statement, the
+saved exception is lost.  The exception information is not available to the
+program during execution of the :keyword:`finally` clause.
+
+.. index::
+   statement: return
+   statement: break
+   statement: continue
+
+When a :keyword:`return`, :keyword:`break` or :keyword:`continue` statement is
+executed in the :keyword:`try` suite of a :keyword:`try`...\ :keyword:`finally`
+statement, the :keyword:`finally` clause is also executed 'on the way out.' A
+:keyword:`continue` statement is illegal in the :keyword:`finally` clause. (The
+reason is a problem with the current implementation --- this restriction may be
+lifted in the future).
+
+Additional information on exceptions can be found in section :ref:`exceptions`,
+and information on using the :keyword:`raise` statement to generate exceptions
+may be found in section :ref:`raise`.
+
+
+.. _with:
+
+The :keyword:`with` statement
+=============================
+
+.. index:: statement: with
+
+.. versionadded:: 2.5
+
+The :keyword:`with` statement is used to wrap the execution of a block with
+methods defined by a context manager (see section :ref:`context-managers`). This
+allows common :keyword:`try`...\ :keyword:`except`...\ :keyword:`finally` usage
+patterns to be encapsulated for convenient reuse.
+
+.. productionlist::
+   with_stmt: "with" `expression` ["as" `target`] ":" `suite`
+
+The execution of the :keyword:`with` statement proceeds as follows:
+
+#. The context expression is evaluated to obtain a context manager.
+
+#. The context manager's :meth:`__enter__` method is invoked.
+
+#. If a target was included in the :keyword:`with` statement, the return value
+   from :meth:`__enter__` is assigned to it.
+
+   .. note::
+
+      The :keyword:`with` statement guarantees that if the :meth:`__enter__` method
+      returns without an error, then :meth:`__exit__` will always be called. Thus, if
+      an error occurs during the assignment to the target list, it will be treated the
+      same as an error occurring within the suite would be. See step 5 below.
+
+#. The suite is executed.
+
+#. The context manager's :meth:`__exit__` method is invoked. If an exception
+   caused the suite to be exited, its type, value, and traceback are passed as
+   arguments to :meth:`__exit__`. Otherwise, three :const:`None` arguments are
+   supplied.
+
+   If the suite was exited due to an exception, and the return value from the
+   :meth:`__exit__` method was false, the exception is reraised. If the return
+   value was true, the exception is suppressed, and execution continues with the
+   statement following the :keyword:`with` statement.
+
+   If the suite was exited for any reason other than an exception, the return value
+   from :meth:`__exit__` is ignored, and execution proceeds at the normal location
+   for the kind of exit that was taken.
+
+.. note::
+
+   In Python 2.5, the :keyword:`with` statement is only allowed when the
+   ``with_statement`` feature has been enabled.  It will always be enabled in
+   Python 2.6.  This ``__future__`` import statement can be used to enable the
+   feature::
+
+      from __future__ import with_statement
+
+
+.. seealso::
+
+   :pep:`0343` - The "with" statement
+      The specification, background, and examples for the Python :keyword:`with`
+      statement.
+
+
+.. _function:
+
+Function definitions
+====================
+
+.. index::
+   pair: function; definition
+   statement: def
+
+.. index::
+   object: user-defined function
+   object: function
+
+A function definition defines a user-defined function object (see section
+:ref:`types`):
+
+.. productionlist::
+   funcdef: [`decorators`] "def" `funcname` "(" [`parameter_list`] ")" ["->" `expression`]? ":" `suite`
+   decorators: `decorator`+
+   decorator: "@" `dotted_name` ["(" [`argument_list` [","]] ")"] NEWLINE
+   dotted_name: `identifier` ("." `identifier`)*
+   parameter_list: (`defparameter` ",")*
+                 : (  "*" [`parameter`] ("," `defparameter`)*
+                 : [, "**" `parameter`]
+                 : | "**" `parameter`
+                 : | `defparameter` [","] )
+   parameter: `identifier` [":" `expression`]
+   defparameter: `parameter` ["=" `expression`]
+   funcname: `identifier`
+
+.. index::
+   pair: function; name
+   pair: name; binding
+
+A function definition is an executable statement.  Its execution binds the
+function name in the current local namespace to a function object (a wrapper
+around the executable code for the function).  This function object contains a
+reference to the current global namespace as the global namespace to be used
+when the function is called.
+
+The function definition does not execute the function body; this gets executed
+only when the function is called.
+
+A function definition may be wrapped by one or more decorator expressions.
+Decorator expressions are evaluated when the function is defined, in the scope
+that contains the function definition.  The result must be a callable, which is
+invoked with the function object as the only argument. The returned value is
+bound to the function name instead of the function object.  Multiple decorators
+are applied in nested fashion. For example, the following code::
+
+   @f1(arg)
+   @f2
+   def func(): pass
+
+is equivalent to::
+
+   def func(): pass
+   func = f1(arg)(f2(func))
+
+.. index:: triple: default; parameter; value
+
+When one or more parameters have the form *parameter* ``=`` *expression*, the
+function is said to have "default parameter values."  For a parameter with a
+default value, the corresponding argument may be omitted from a call, in which
+case the parameter's default value is substituted.  If a parameter has a default
+value, all following parameters up until the  "``*``" must also have a default
+value --- this is a syntactic  restriction that is not expressed by the grammar.
+
+**Default parameter values are evaluated when the function definition is
+executed.**  This means that the expression is evaluated once, when the function
+is defined, and that that same "pre-computed" value is used for each call.  This
+is especially important to understand when a default parameter is a mutable
+object, such as a list or a dictionary: if the function modifies the object
+(e.g. by appending an item to a list), the default value is in effect modified.
+This is generally not what was intended.  A way around this  is to use ``None``
+as the default, and explicitly test for it in the body of the function, e.g.::
+
+   def whats_on_the_telly(penguin=None):
+       if penguin is None:
+           penguin = []
+       penguin.append("property of the zoo")
+       return penguin
+
+Function call semantics are described in more detail in section :ref:`calls`. A
+function call always assigns values to all parameters mentioned in the parameter
+list, either from position arguments, from keyword arguments, or from default
+values.  If the form "``*identifier``" is present, it is initialized to a tuple
+receiving any excess positional parameters, defaulting to the empty tuple.  If
+the form "``**identifier``" is present, it is initialized to a new dictionary
+receiving any excess keyword arguments, defaulting to a new empty dictionary.
+Parameters after "``*``" or "``*identifier``" are keyword-only parameters and
+may only be passed used keyword arguments.
+
+.. index:: pair: function; annotations
+
+Parameters may have annotations of the form "``: expression``" following the
+parameter name. Any parameter may have an annotation even those of the form
+``*identifier`` or ``**identifier``. Functions may have "return" annotation of
+the form "``-> expression``" after the parameter list. These annotations can be
+any valid Python expression and are evaluated when the function definition is
+executed. Annotations may be evaluated in a different order than they appear in
+the source code. The presence of annotations does not change the semantics of a
+function. The annotation values are available as values of a dictionary  keyed
+by the parameters' names in the :attr:`__annotations__` attribute of the
+function object.
+
+.. index:: pair: lambda; form
+
+It is also possible to create anonymous functions (functions not bound to a
+name), for immediate use in expressions.  This uses lambda forms, described in
+section :ref:`lambda`.  Note that the lambda form is merely a shorthand for a
+simplified function definition; a function defined in a ":keyword:`def`"
+statement can be passed around or assigned to another name just like a function
+defined by a lambda form.  The ":keyword:`def`" form is actually more powerful
+since it allows the execution of multiple statements and annotations.
+
+**Programmer's note:** Functions are first-class objects.  A "``def``" form
+executed inside a function definition defines a local function that can be
+returned or passed around.  Free variables used in the nested function can
+access the local variables of the function containing the def.  See section
+:ref:`naming` for details.
+
+
+.. _class:
+
+Class definitions
+=================
+
+.. index::
+   pair: class; definition
+   statement: class
+
+.. index:: object: class
+
+A class definition defines a class object (see section :ref:`types`):
+
+.. productionlist::
+   classdef: "class" `classname` [`inheritance`] ":" `suite`
+   inheritance: "(" [`expression_list`] ")"
+   classname: `identifier`
+
+.. index::
+   single: inheritance
+   pair: class; name
+   pair: name; binding
+   pair: execution; frame
+
+A class definition is an executable statement.  It first evaluates the
+inheritance list, if present.  Each item in the inheritance list should evaluate
+to a class object or class type which allows subclassing.  The class's suite is
+then executed in a new execution frame (see section :ref:`naming`), using a
+newly created local namespace and the original global namespace. (Usually, the
+suite contains only function definitions.)  When the class's suite finishes
+execution, its execution frame is discarded but its local namespace is saved.  A
+class object is then created using the inheritance list for the base classes and
+the saved local namespace for the attribute dictionary.  The class name is bound
+to this class object in the original local namespace.
+
+**Programmer's note:** Variables defined in the class definition are class
+variables; they are shared by all instances.  To define instance variables, they
+must be given a value in the :meth:`__init__` method or in another method.  Both
+class and instance variables are accessible through the notation
+"``self.name``", and an instance variable hides a class variable with the same
+name when accessed in this way.  Class variables with immutable values can be
+used as defaults for instance variables. For new-style classes, descriptors can
+be used to create instance variables with different implementation details.
+
+.. rubric:: Footnotes
+
+.. [#] The exception is propogated to the invocation stack only if there is no
+   :keyword:`finally` clause that negates the exception.
+
+.. [#] Currently, control "flows off the end" except in the case of an exception or the
+   execution of a :keyword:`return`, :keyword:`continue`, or :keyword:`break`
+   statement.
+
diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
new file mode 100644
index 0000000..2f6013e
--- /dev/null
+++ b/Doc/reference/datamodel.rst
@@ -0,0 +1,2118 @@
+
+.. _datamodel:
+
+**********
+Data model
+**********
+
+
+.. _objects:
+
+Objects, values and types
+=========================
+
+.. index::
+   single: object
+   single: data
+
+:dfn:`Objects` are Python's abstraction for data.  All data in a Python program
+is represented by objects or by relations between objects. (In a sense, and in
+conformance to Von Neumann's model of a "stored program computer," code is also
+represented by objects.)
+
+.. index::
+   builtin: id
+   builtin: type
+   single: identity of an object
+   single: value of an object
+   single: type of an object
+   single: mutable object
+   single: immutable object
+
+Every object has an identity, a type and a value.  An object's *identity* never
+changes once it has been created; you may think of it as the object's address in
+memory.  The ':keyword:`is`' operator compares the identity of two objects; the
+:func:`id` function returns an integer representing its identity (currently
+implemented as its address). An object's :dfn:`type` is also unchangeable. [#]_
+An object's type determines the operations that the object supports (e.g., "does
+it have a length?") and also defines the possible values for objects of that
+type.  The :func:`type` function returns an object's type (which is an object
+itself).  The *value* of some objects can change.  Objects whose value can
+change are said to be *mutable*; objects whose value is unchangeable once they
+are created are called *immutable*. (The value of an immutable container object
+that contains a reference to a mutable object can change when the latter's value
+is changed; however the container is still considered immutable, because the
+collection of objects it contains cannot be changed.  So, immutability is not
+strictly the same as having an unchangeable value, it is more subtle.) An
+object's mutability is determined by its type; for instance, numbers, strings
+and tuples are immutable, while dictionaries and lists are mutable.
+
+.. index::
+   single: garbage collection
+   single: reference counting
+   single: unreachable object
+
+Objects are never explicitly destroyed; however, when they become unreachable
+they may be garbage-collected.  An implementation is allowed to postpone garbage
+collection or omit it altogether --- it is a matter of implementation quality
+how garbage collection is implemented, as long as no objects are collected that
+are still reachable.  (Implementation note: the current implementation uses a
+reference-counting scheme with (optional) delayed detection of cyclically linked
+garbage, which collects most objects as soon as they become unreachable, but is
+not guaranteed to collect garbage containing circular references.  See the
+documentation of the :mod:`gc` module for information on controlling the
+collection of cyclic garbage.)
+
+Note that the use of the implementation's tracing or debugging facilities may
+keep objects alive that would normally be collectable. Also note that catching
+an exception with a ':keyword:`try`...\ :keyword:`except`' statement may keep
+objects alive.
+
+Some objects contain references to "external" resources such as open files or
+windows.  It is understood that these resources are freed when the object is
+garbage-collected, but since garbage collection is not guaranteed to happen,
+such objects also provide an explicit way to release the external resource,
+usually a :meth:`close` method. Programs are strongly recommended to explicitly
+close such objects.  The ':keyword:`try`...\ :keyword:`finally`' statement
+provides a convenient way to do this.
+
+.. index:: single: container
+
+Some objects contain references to other objects; these are called *containers*.
+Examples of containers are tuples, lists and dictionaries.  The references are
+part of a container's value.  In most cases, when we talk about the value of a
+container, we imply the values, not the identities of the contained objects;
+however, when we talk about the mutability of a container, only the identities
+of the immediately contained objects are implied.  So, if an immutable container
+(like a tuple) contains a reference to a mutable object, its value changes if
+that mutable object is changed.
+
+Types affect almost all aspects of object behavior.  Even the importance of
+object identity is affected in some sense: for immutable types, operations that
+compute new values may actually return a reference to any existing object with
+the same type and value, while for mutable objects this is not allowed.  E.g.,
+after ``a = 1; b = 1``, ``a`` and ``b`` may or may not refer to the same object
+with the value one, depending on the implementation, but after ``c = []; d =
+[]``, ``c`` and ``d`` are guaranteed to refer to two different, unique, newly
+created empty lists. (Note that ``c = d = []`` assigns the same object to both
+``c`` and ``d``.)
+
+
+.. _types:
+
+The standard type hierarchy
+===========================
+
+.. index::
+   single: type
+   pair: data; type
+   pair: type; hierarchy
+   pair: extension; module
+   pair: C; language
+
+Below is a list of the types that are built into Python.  Extension modules
+(written in C, Java, or other languages, depending on the implementation) can
+define additional types.  Future versions of Python may add types to the type
+hierarchy (e.g., rational numbers, efficiently stored arrays of integers, etc.).
+
+.. index::
+   single: attribute
+   pair: special; attribute
+   triple: generic; special; attribute
+
+Some of the type descriptions below contain a paragraph listing 'special
+attributes.'  These are attributes that provide access to the implementation and
+are not intended for general use.  Their definition may change in the future.
+
+None
+   .. index:: object: None
+
+   This type has a single value.  There is a single object with this value. This
+   object is accessed through the built-in name ``None``. It is used to signify the
+   absence of a value in many situations, e.g., it is returned from functions that
+   don't explicitly return anything. Its truth value is false.
+
+NotImplemented
+   .. index:: object: NotImplemented
+
+   This type has a single value.  There is a single object with this value. This
+   object is accessed through the built-in name ``NotImplemented``. Numeric methods
+   and rich comparison methods may return this value if they do not implement the
+   operation for the operands provided.  (The interpreter will then try the
+   reflected operation, or some other fallback, depending on the operator.)  Its
+   truth value is true.
+
+Ellipsis
+   .. index:: object: Ellipsis
+
+   This type has a single value.  There is a single object with this value. This
+   object is accessed through the literal ``...`` or the built-in name
+   ``Ellipsis``.  Its truth value is true.
+
+Numbers
+   .. index:: object: numeric
+
+   These are created by numeric literals and returned as results by arithmetic
+   operators and arithmetic built-in functions.  Numeric objects are immutable;
+   once created their value never changes.  Python numbers are of course strongly
+   related to mathematical numbers, but subject to the limitations of numerical
+   representation in computers.
+
+   Python distinguishes between integers, floating point numbers, and complex
+   numbers:
+
+   Integers
+      .. index:: object: integer
+
+      These represent elements from the mathematical set of integers (positive and
+      negative).
+
+      There are three types of integers:
+
+      Plain integers
+         .. index::
+            object: plain integer
+            single: OverflowError (built-in exception)
+
+         These represent numbers in the range -2147483648 through 2147483647. (The range
+         may be larger on machines with a larger natural word size, but not smaller.)
+         When the result of an operation would fall outside this range, the result is
+         normally returned as a long integer (in some cases, the exception
+         :exc:`OverflowError` is raised instead). For the purpose of shift and mask
+         operations, integers are assumed to have a binary, 2's complement notation using
+         32 or more bits, and hiding no bits from the user (i.e., all 4294967296
+         different bit patterns correspond to different values).
+
+      Long integers
+         .. index:: object: long integer
+
+         These represent numbers in an unlimited range, subject to available (virtual)
+         memory only.  For the purpose of shift and mask operations, a binary
+         representation is assumed, and negative numbers are represented in a variant of
+         2's complement which gives the illusion of an infinite string of sign bits
+         extending to the left.
+
+      Booleans
+         .. index::
+            object: Boolean
+            single: False
+            single: True
+
+         These represent the truth values False and True.  The two objects representing
+         the values False and True are the only Boolean objects. The Boolean type is a
+         subtype of plain integers, and Boolean values behave like the values 0 and 1,
+         respectively, in almost all contexts, the exception being that when converted to
+         a string, the strings ``"False"`` or ``"True"`` are returned, respectively.
+
+      .. index:: pair: integer; representation
+
+      The rules for integer representation are intended to give the most meaningful
+      interpretation of shift and mask operations involving negative integers and the
+      least surprises when switching between the plain and long integer domains.  Any
+      operation except left shift, if it yields a result in the plain integer domain
+      without causing overflow, will yield the same result in the long integer domain
+      or when using mixed operands.
+
+      .. % Integers
+
+   Floating point numbers
+      .. index::
+         object: floating point
+         pair: floating point; number
+         pair: C; language
+         pair: Java; language
+
+      These represent machine-level double precision floating point numbers. You are
+      at the mercy of the underlying machine architecture (and C or Java
+      implementation) for the accepted range and handling of overflow. Python does not
+      support single-precision floating point numbers; the savings in processor and
+      memory usage that are usually the reason for using these is dwarfed by the
+      overhead of using objects in Python, so there is no reason to complicate the
+      language with two kinds of floating point numbers.
+
+   Complex numbers
+      .. index::
+         object: complex
+         pair: complex; number
+
+      These represent complex numbers as a pair of machine-level double precision
+      floating point numbers.  The same caveats apply as for floating point numbers.
+      The real and imaginary parts of a complex number ``z`` can be retrieved through
+      the read-only attributes ``z.real`` and ``z.imag``.
+
+   .. % Numbers
+
+Sequences
+   .. index::
+      builtin: len
+      object: sequence
+      single: index operation
+      single: item selection
+      single: subscription
+
+   These represent finite ordered sets indexed by non-negative numbers. The
+   built-in function :func:`len` returns the number of items of a sequence. When
+   the length of a sequence is *n*, the index set contains the numbers 0, 1,
+   ..., *n*-1.  Item *i* of sequence *a* is selected by ``a[i]``.
+
+   .. index:: single: slicing
+
+   Sequences also support slicing: ``a[i:j]`` selects all items with index *k* such
+   that *i* ``<=`` *k* ``<`` *j*.  When used as an expression, a slice is a
+   sequence of the same type.  This implies that the index set is renumbered so
+   that it starts at 0.
+
+   .. index:: single: extended slicing
+
+   Some sequences also support "extended slicing" with a third "step" parameter:
+   ``a[i:j:k]`` selects all items of *a* with index *x* where ``x = i + n*k``, *n*
+   ``>=`` ``0`` and *i* ``<=`` *x* ``<`` *j*.
+
+   Sequences are distinguished according to their mutability:
+
+   Immutable sequences
+      .. index::
+         object: immutable sequence
+         object: immutable
+
+      An object of an immutable sequence type cannot change once it is created.  (If
+      the object contains references to other objects, these other objects may be
+      mutable and may be changed; however, the collection of objects directly
+      referenced by an immutable object cannot change.)
+
+      The following types are immutable sequences:
+
+      Strings
+         .. index::
+            builtin: chr
+            builtin: ord
+            object: string
+            single: character
+            single: byte
+            single: ASCII@ASCII
+
+         The items of a string are characters.  There is no separate character type; a
+         character is represented by a string of one item. Characters represent (at
+         least) 8-bit bytes.  The built-in functions :func:`chr` and :func:`ord` convert
+         between characters and nonnegative integers representing the byte values.  Bytes
+         with the values 0-127 usually represent the corresponding ASCII values, but the
+         interpretation of values is up to the program.  The string data type is also
+         used to represent arrays of bytes, e.g., to hold data read from a file.
+
+         .. index::
+            single: ASCII@ASCII
+            single: EBCDIC
+            single: character set
+            pair: string; comparison
+            builtin: chr
+            builtin: ord
+
+         (On systems whose native character set is not ASCII, strings may use EBCDIC in
+         their internal representation, provided the functions :func:`chr` and
+         :func:`ord` implement a mapping between ASCII and EBCDIC, and string comparison
+         preserves the ASCII order. Or perhaps someone can propose a better rule?)
+
+      Unicode
+         .. index::
+            builtin: unichr
+            builtin: ord
+            builtin: unicode
+            object: unicode
+            single: character
+            single: integer
+            single: Unicode
+
+         The items of a Unicode object are Unicode code units.  A Unicode code unit is
+         represented by a Unicode object of one item and can hold either a 16-bit or
+         32-bit value representing a Unicode ordinal (the maximum value for the ordinal
+         is given in ``sys.maxunicode``, and depends on how Python is configured at
+         compile time).  Surrogate pairs may be present in the Unicode object, and will
+         be reported as two separate items.  The built-in functions :func:`unichr` and
+         :func:`ord` convert between code units and nonnegative integers representing the
+         Unicode ordinals as defined in the Unicode Standard 3.0. Conversion from and to
+         other encodings are possible through the Unicode method :meth:`encode` and the
+         built-in function :func:`unicode`.
+
+      Tuples
+         .. index::
+            object: tuple
+            pair: singleton; tuple
+            pair: empty; tuple
+
+         The items of a tuple are arbitrary Python objects. Tuples of two or more items
+         are formed by comma-separated lists of expressions.  A tuple of one item (a
+         'singleton') can be formed by affixing a comma to an expression (an expression
+         by itself does not create a tuple, since parentheses must be usable for grouping
+         of expressions).  An empty tuple can be formed by an empty pair of parentheses.
+
+      .. % Immutable sequences
+
+   Mutable sequences
+      .. index::
+         object: mutable sequence
+         object: mutable
+         pair: assignment; statement
+         single: delete
+         statement: del
+         single: subscription
+         single: slicing
+
+      Mutable sequences can be changed after they are created.  The subscription and
+      slicing notations can be used as the target of assignment and :keyword:`del`
+      (delete) statements.
+
+      There is currently a single intrinsic mutable sequence type:
+
+      Lists
+         .. index:: object: list
+
+         The items of a list are arbitrary Python objects.  Lists are formed by placing a
+         comma-separated list of expressions in square brackets. (Note that there are no
+         special cases needed to form lists of length 0 or 1.)
+
+      .. index:: module: array
+
+      The extension module :mod:`array` provides an additional example of a mutable
+      sequence type.
+
+      .. % Mutable sequences
+
+   .. % Sequences
+
+Set types
+   .. index::
+      builtin: len
+      object: set type
+
+   These represent unordered, finite sets of unique, immutable objects. As such,
+   they cannot be indexed by any subscript. However, they can be iterated over, and
+   the built-in function :func:`len` returns the number of items in a set. Common
+   uses for sets are fast membership testing, removing duplicates from a sequence,
+   and computing mathematical operations such as intersection, union, difference,
+   and symmetric difference.
+
+   For set elements, the same immutability rules apply as for dictionary keys. Note
+   that numeric types obey the normal rules for numeric comparison: if two numbers
+   compare equal (e.g., ``1`` and ``1.0``), only one of them can be contained in a
+   set.
+
+   There are currently two intrinsic set types:
+
+   Sets
+      .. index:: object: set
+
+      These represent a mutable set. They are created by the built-in :func:`set`
+      constructor and can be modified afterwards by several methods, such as
+      :meth:`add`.
+
+   Frozen sets
+      .. index:: object: frozenset
+
+      These represent an immutable set. They are created by the built-in
+      :func:`frozenset` constructor. As a frozenset is immutable and hashable, it can
+      be used again as an element of another set, or as a dictionary key.
+
+   .. % Set types
+
+Mappings
+   .. index::
+      builtin: len
+      single: subscription
+      object: mapping
+
+   These represent finite sets of objects indexed by arbitrary index sets. The
+   subscript notation ``a[k]`` selects the item indexed by ``k`` from the mapping
+   ``a``; this can be used in expressions and as the target of assignments or
+   :keyword:`del` statements. The built-in function :func:`len` returns the number
+   of items in a mapping.
+
+   There is currently a single intrinsic mapping type:
+
+   Dictionaries
+      .. index:: object: dictionary
+
+      These represent finite sets of objects indexed by nearly arbitrary values.  The
+      only types of values not acceptable as keys are values containing lists or
+      dictionaries or other mutable types that are compared by value rather than by
+      object identity, the reason being that the efficient implementation of
+      dictionaries requires a key's hash value to remain constant. Numeric types used
+      for keys obey the normal rules for numeric comparison: if two numbers compare
+      equal (e.g., ``1`` and ``1.0``) then they can be used interchangeably to index
+      the same dictionary entry.
+
+      Dictionaries are mutable; they can be created by the ``{...}`` notation (see
+      section :ref:`dict`).
+
+      .. index::
+         module: dbm
+         module: gdbm
+         module: bsddb
+
+      The extension modules :mod:`dbm`, :mod:`gdbm`, and :mod:`bsddb` provide
+      additional examples of mapping types.
+
+   .. % Mapping types
+
+Callable types
+   .. index::
+      object: callable
+      pair: function; call
+      single: invocation
+      pair: function; argument
+
+   These are the types to which the function call operation (see section
+   :ref:`calls`) can be applied:
+
+   User-defined functions
+      .. index::
+         pair: user-defined; function
+         object: function
+         object: user-defined function
+
+      A user-defined function object is created by a function definition (see
+      section :ref:`function`).  It should be called with an argument list
+      containing the same number of items as the function's formal parameter
+      list.
+
+      Special attributes:
+
+      +-------------------------+-------------------------------+-----------+
+      | Attribute               | Meaning                       |           |
+      +=========================+===============================+===========+
+      | :attr:`__doc__`         | The function's documentation  | Writable  |
+      |                         | string, or ``None`` if        |           |
+      |                         | unavailable                   |           |
+      +-------------------------+-------------------------------+-----------+
+      | :attr:`__name__`        | The function's name           | Writable  |
+      +-------------------------+-------------------------------+-----------+
+      | :attr:`__module__`      | The name of the module the    | Writable  |
+      |                         | function was defined in, or   |           |
+      |                         | ``None`` if unavailable.      |           |
+      +-------------------------+-------------------------------+-----------+
+      | :attr:`__defaults__`    | A tuple containing default    | Writable  |
+      |                         | argument values for those     |           |
+      |                         | arguments that have defaults, |           |
+      |                         | or ``None`` if no arguments   |           |
+      |                         | have a default value          |           |
+      +-------------------------+-------------------------------+-----------+
+      | :attr:`__code__`        | The code object representing  | Writable  |
+      |                         | the compiled function body.   |           |
+      +-------------------------+-------------------------------+-----------+
+      | :attr:`__globals__`     | A reference to the dictionary | Read-only |
+      |                         | that holds the function's     |           |
+      |                         | global variables --- the      |           |
+      |                         | global namespace of the       |           |
+      |                         | module in which the function  |           |
+      |                         | was defined.                  |           |
+      +-------------------------+-------------------------------+-----------+
+      | :attr:`__dict__`        | The namespace supporting      | Writable  |
+      |                         | arbitrary function            |           |
+      |                         | attributes.                   |           |
+      +-------------------------+-------------------------------+-----------+
+      | :attr:`__closure__`     | ``None`` or a tuple of cells  | Read-only |
+      |                         | that contain bindings for the |           |
+      |                         | function's free variables.    |           |
+      +-------------------------+-------------------------------+-----------+
+      | :attr:`__annotations__` | A dict containing annotations | Writable  |
+      |                         | of parameters.  The keys of   |           |
+      |                         | the dict are the parameter    |           |
+      |                         | names, or ``'return'`` for    |           |
+      |                         | the return annotation, if     |           |
+      |                         | provided.                     |           |
+      +-------------------------+-------------------------------+-----------+
+      | :attr:`__kwdefaults__`  | A dict containing defaults    | Writable  |
+      |                         | for keyword-only parameters.  |           |
+      +-------------------------+-------------------------------+-----------+
+
+      Most of the attributes labelled "Writable" check the type of the assigned value.
+
+      .. versionchanged:: 2.4
+         ``__name__`` is now writable.
+
+      Function objects also support getting and setting arbitrary attributes, which
+      can be used, for example, to attach metadata to functions.  Regular attribute
+      dot-notation is used to get and set such attributes. *Note that the current
+      implementation only supports function attributes on user-defined functions.
+      Function attributes on built-in functions may be supported in the future.*
+
+      Additional information about a function's definition can be retrieved from its
+      code object; see the description of internal types below.
+
+      .. index::
+         single: __doc__ (function attribute)
+         single: __name__ (function attribute)
+         single: __module__ (function attribute)
+         single: __dict__ (function attribute)
+         single: __defaults__ (function attribute)
+         single: __closure__ (function attribute)
+         single: __code__ (function attribute)
+         single: __globals__ (function attribute)
+         single: __annotations__ (function attribute)
+         single: __kwdefaults__ (function attribute)
+         pair: global; namespace
+
+   User-defined methods
+      .. index::
+         object: method
+         object: user-defined method
+         pair: user-defined; method
+
+      A user-defined method object combines a class, a class instance (or ``None``)
+      and any callable object (normally a user-defined function).
+
+      Special read-only attributes: :attr:`im_self` is the class instance object,
+      :attr:`im_func` is the function object; :attr:`im_class` is the class of
+      :attr:`im_self` for bound methods or the class that asked for the method for
+      unbound methods; :attr:`__doc__` is the method's documentation (same as
+      ``im_func.__doc__``); :attr:`__name__` is the method name (same as
+      ``im_func.__name__``); :attr:`__module__` is the name of the module the method
+      was defined in, or ``None`` if unavailable.
+
+      .. versionchanged:: 2.2
+         :attr:`im_self` used to refer to the class that defined the method.
+
+      .. index::
+         single: __doc__ (method attribute)
+         single: __name__ (method attribute)
+         single: __module__ (method attribute)
+         single: im_func (method attribute)
+         single: im_self (method attribute)
+
+      Methods also support accessing (but not setting) the arbitrary function
+      attributes on the underlying function object.
+
+      User-defined method objects may be created when getting an attribute of a class
+      (perhaps via an instance of that class), if that attribute is a user-defined
+      function object, an unbound user-defined method object, or a class method
+      object. When the attribute is a user-defined method object, a new method object
+      is only created if the class from which it is being retrieved is the same as, or
+      a derived class of, the class stored in the original method object; otherwise,
+      the original method object is used as it is.
+
+      .. index::
+         single: im_class (method attribute)
+         single: im_func (method attribute)
+         single: im_self (method attribute)
+
+      When a user-defined method object is created by retrieving a user-defined
+      function object from a class, its :attr:`im_self` attribute is ``None``
+      and the method object is said to be unbound. When one is created by
+      retrieving a user-defined function object from a class via one of its
+      instances, its :attr:`im_self` attribute is the instance, and the method
+      object is said to be bound. In either case, the new method's
+      :attr:`im_class` attribute is the class from which the retrieval takes
+      place, and its :attr:`im_func` attribute is the original function object.
+
+      .. index:: single: im_func (method attribute)
+
+      When a user-defined method object is created by retrieving another method object
+      from a class or instance, the behaviour is the same as for a function object,
+      except that the :attr:`im_func` attribute of the new instance is not the
+      original method object but its :attr:`im_func` attribute.
+
+      .. index::
+         single: im_class (method attribute)
+         single: im_func (method attribute)
+         single: im_self (method attribute)
+
+      When a user-defined method object is created by retrieving a class method object
+      from a class or instance, its :attr:`im_self` attribute is the class itself (the
+      same as the :attr:`im_class` attribute), and its :attr:`im_func` attribute is
+      the function object underlying the class method.
+
+      When an unbound user-defined method object is called, the underlying function
+      (:attr:`im_func`) is called, with the restriction that the first argument must
+      be an instance of the proper class (:attr:`im_class`) or of a derived class
+      thereof.
+
+      When a bound user-defined method object is called, the underlying function
+      (:attr:`im_func`) is called, inserting the class instance (:attr:`im_self`) in
+      front of the argument list.  For instance, when :class:`C` is a class which
+      contains a definition for a function :meth:`f`, and ``x`` is an instance of
+      :class:`C`, calling ``x.f(1)`` is equivalent to calling ``C.f(x, 1)``.
+
+      When a user-defined method object is derived from a class method object, the
+      "class instance" stored in :attr:`im_self` will actually be the class itself, so
+      that calling either ``x.f(1)`` or ``C.f(1)`` is equivalent to calling ``f(C,1)``
+      where ``f`` is the underlying function.
+
+      Note that the transformation from function object to (unbound or bound) method
+      object happens each time the attribute is retrieved from the class or instance.
+      In some cases, a fruitful optimization is to assign the attribute to a local
+      variable and call that local variable. Also notice that this transformation only
+      happens for user-defined functions; other callable objects (and all non-callable
+      objects) are retrieved without transformation.  It is also important to note
+      that user-defined functions which are attributes of a class instance are not
+      converted to bound methods; this *only* happens when the function is an
+      attribute of the class.
+
+   Generator functions
+      .. index::
+         single: generator; function
+         single: generator; iterator
+
+      A function or method which uses the :keyword:`yield` statement (see section
+      :ref:`yield`) is called a :dfn:`generator
+      function`.  Such a function, when called, always returns an iterator object
+      which can be used to execute the body of the function:  calling the iterator's
+      :meth:`__next__` method will cause the function to execute until it provides a
+      value using the :keyword:`yield` statement.  When the function executes a
+      :keyword:`return` statement or falls off the end, a :exc:`StopIteration`
+      exception is raised and the iterator will have reached the end of the set of
+      values to be returned.
+
+   Built-in functions
+      .. index::
+         object: built-in function
+         object: function
+         pair: C; language
+
+      A built-in function object is a wrapper around a C function.  Examples of
+      built-in functions are :func:`len` and :func:`math.sin` (:mod:`math` is a
+      standard built-in module). The number and type of the arguments are
+      determined by the C function. Special read-only attributes:
+      :attr:`__doc__` is the function's documentation string, or ``None`` if
+      unavailable; :attr:`__name__` is the function's name; :attr:`__self__` is
+      set to ``None`` (but see the next item); :attr:`__module__` is the name of
+      the module the function was defined in or ``None`` if unavailable.
+
+   Built-in methods
+      .. index::
+         object: built-in method
+         object: method
+         pair: built-in; method
+
+      This is really a different disguise of a built-in function, this time containing
+      an object passed to the C function as an implicit extra argument.  An example of
+      a built-in method is ``alist.append()``, assuming *alist* is a list object. In
+      this case, the special read-only attribute :attr:`__self__` is set to the object
+      denoted by *list*.
+
+   Class Types
+      Class types, or "new-style classes," are callable.  These objects normally act
+      as factories for new instances of themselves, but variations are possible for
+      class types that override :meth:`__new__`.  The arguments of the call are passed
+      to :meth:`__new__` and, in the typical case, to :meth:`__init__` to initialize
+      the new instance.
+
+   Classic Classes
+      .. index::
+         single: __init__() (object method)
+         object: class
+         object: class instance
+         object: instance
+         pair: class object; call
+
+      Class objects are described below.  When a class object is called, a new class
+      instance (also described below) is created and returned.  This implies a call to
+      the class's :meth:`__init__` method if it has one.  Any arguments are passed on
+      to the :meth:`__init__` method.  If there is no :meth:`__init__` method, the
+      class must be called without arguments.
+
+   Class instances
+      Class instances are described below.  Class instances are callable only when the
+      class has a :meth:`__call__` method; ``x(arguments)`` is a shorthand for
+      ``x.__call__(arguments)``.
+
+Modules
+   .. index::
+      statement: import
+      object: module
+
+   Modules are imported by the :keyword:`import` statement (see section
+   :ref:`import`). A module object has a
+   namespace implemented by a dictionary object (this is the dictionary referenced
+   by the __globals__ attribute of functions defined in the module).  Attribute
+   references are translated to lookups in this dictionary, e.g., ``m.x`` is
+   equivalent to ``m.__dict__["x"]``. A module object does not contain the code
+   object used to initialize the module (since it isn't needed once the
+   initialization is done).
+
+   .. % 
+
+   Attribute assignment updates the module's namespace dictionary, e.g., ``m.x =
+   1`` is equivalent to ``m.__dict__["x"] = 1``.
+
+   .. index:: single: __dict__ (module attribute)
+
+   Special read-only attribute: :attr:`__dict__` is the module's namespace as a
+   dictionary object.
+
+   .. index::
+      single: __name__ (module attribute)
+      single: __doc__ (module attribute)
+      single: __file__ (module attribute)
+      pair: module; namespace
+
+   Predefined (writable) attributes: :attr:`__name__` is the module's name;
+   :attr:`__doc__` is the module's documentation string, or ``None`` if
+   unavailable; :attr:`__file__` is the pathname of the file from which the module
+   was loaded, if it was loaded from a file. The :attr:`__file__` attribute is not
+   present for C modules that are statically linked into the interpreter; for
+   extension modules loaded dynamically from a shared library, it is the pathname
+   of the shared library file.
+
+Classes
+   Class objects are created by class definitions (see section :ref:`class`).  A
+   class has a namespace implemented by a dictionary object. Class attribute
+   references are translated to lookups in this dictionary, e.g., ``C.x`` is
+   translated to ``C.__dict__["x"]``. When the attribute name is not found
+   there, the attribute search continues in the base classes.  The search is
+   depth-first, left-to-right in the order of occurrence in the base class list.
+
+   .. index::
+      object: class
+      object: class instance
+      object: instance
+      pair: class object; call
+      single: container
+      object: dictionary
+      pair: class; attribute
+
+   When a class attribute reference (for class :class:`C`, say) would yield a
+   user-defined function object or an unbound user-defined method object whose
+   associated class is either :class:`C` or one of its base classes, it is
+   transformed into an unbound user-defined method object whose :attr:`im_class`
+   attribute is :class:`C`. When it would yield a class method object, it is
+   transformed into a bound user-defined method object whose :attr:`im_class`
+   and :attr:`im_self` attributes are both :class:`C`.  When it would yield a
+   static method object, it is transformed into the object wrapped by the static
+   method object. See section :ref:`descriptors` for another way in which
+   attributes retrieved from a class may differ from those actually contained in
+   its :attr:`__dict__`.
+
+   .. index:: triple: class; attribute; assignment
+
+   Class attribute assignments update the class's dictionary, never the dictionary
+   of a base class.
+
+   .. index:: pair: class object; call
+
+   A class object can be called (see above) to yield a class instance (see below).
+
+   .. index::
+      single: __name__ (class attribute)
+      single: __module__ (class attribute)
+      single: __dict__ (class attribute)
+      single: __bases__ (class attribute)
+      single: __doc__ (class attribute)
+
+   Special attributes: :attr:`__name__` is the class name; :attr:`__module__` is
+   the module name in which the class was defined; :attr:`__dict__` is the
+   dictionary containing the class's namespace; :attr:`__bases__` is a tuple
+   (possibly empty or a singleton) containing the base classes, in the order of
+   their occurrence in the base class list; :attr:`__doc__` is the class's
+   documentation string, or None if undefined.
+
+Class instances
+   .. index::
+      object: class instance
+      object: instance
+      pair: class; instance
+      pair: class instance; attribute
+
+   A class instance is created by calling a class object (see above). A class
+   instance has a namespace implemented as a dictionary which is the first place in
+   which attribute references are searched.  When an attribute is not found there,
+   and the instance's class has an attribute by that name, the search continues
+   with the class attributes.  If a class attribute is found that is a user-defined
+   function object or an unbound user-defined method object whose associated class
+   is the class (call it :class:`C`) of the instance for which the attribute
+   reference was initiated or one of its bases, it is transformed into a bound
+   user-defined method object whose :attr:`im_class` attribute is :class:`C` and
+   whose :attr:`im_self` attribute is the instance. Static method and class method
+   objects are also transformed, as if they had been retrieved from class
+   :class:`C`; see above under "Classes". See section :ref:`descriptors` for
+   another way in which attributes of a class retrieved via its instances may
+   differ from the objects actually stored in the class's :attr:`__dict__`. If no
+   class attribute is found, and the object's class has a :meth:`__getattr__`
+   method, that is called to satisfy the lookup.
+
+   .. index:: triple: class instance; attribute; assignment
+
+   Attribute assignments and deletions update the instance's dictionary, never a
+   class's dictionary.  If the class has a :meth:`__setattr__` or
+   :meth:`__delattr__` method, this is called instead of updating the instance
+   dictionary directly.
+
+   .. index::
+      object: numeric
+      object: sequence
+      object: mapping
+
+   Class instances can pretend to be numbers, sequences, or mappings if they have
+   methods with certain special names.  See section :ref:`specialnames`.
+
+   .. index::
+      single: __dict__ (instance attribute)
+      single: __class__ (instance attribute)
+
+   Special attributes: :attr:`__dict__` is the attribute dictionary;
+   :attr:`__class__` is the instance's class.
+
+Files
+   .. index::
+      object: file
+      builtin: open
+      single: popen() (in module os)
+      single: makefile() (socket method)
+      single: sys.stdin
+      single: sys.stdout
+      single: sys.stderr
+      single: stdio
+      single: stdin (in module sys)
+      single: stdout (in module sys)
+      single: stderr (in module sys)
+
+   A file object represents an open file.  File objects are created by the
+   :func:`open` built-in function, and also by :func:`os.popen`,
+   :func:`os.fdopen`, and the :meth:`makefile` method of socket objects (and
+   perhaps by other functions or methods provided by extension modules).  The
+   objects ``sys.stdin``, ``sys.stdout`` and ``sys.stderr`` are initialized to
+   file objects corresponding to the interpreter's standard input, output and
+   error streams.  See :ref:`bltin-file-objects` for complete documentation of
+   file objects.
+
+Internal types
+   .. index::
+      single: internal type
+      single: types, internal
+
+   A few types used internally by the interpreter are exposed to the user. Their
+   definitions may change with future versions of the interpreter, but they are
+   mentioned here for completeness.
+
+   Code objects
+      .. index::
+         single: bytecode
+         object: code
+
+      Code objects represent *byte-compiled* executable Python code, or *bytecode*.
+      The difference between a code object and a function object is that the function
+      object contains an explicit reference to the function's globals (the module in
+      which it was defined), while a code object contains no context; also the default
+      argument values are stored in the function object, not in the code object
+      (because they represent values calculated at run-time).  Unlike function
+      objects, code objects are immutable and contain no references (directly or
+      indirectly) to mutable objects.
+
+      Special read-only attributes: :attr:`co_name` gives the function name;
+      :attr:`co_argcount` is the number of positional arguments (including arguments
+      with default values); :attr:`co_nlocals` is the number of local variables used
+      by the function (including arguments); :attr:`co_varnames` is a tuple containing
+      the names of the local variables (starting with the argument names);
+      :attr:`co_cellvars` is a tuple containing the names of local variables that are
+      referenced by nested functions; :attr:`co_freevars` is a tuple containing the
+      names of free variables; :attr:`co_code` is a string representing the sequence
+      of bytecode instructions; :attr:`co_consts` is a tuple containing the literals
+      used by the bytecode; :attr:`co_names` is a tuple containing the names used by
+      the bytecode; :attr:`co_filename` is the filename from which the code was
+      compiled; :attr:`co_firstlineno` is the first line number of the function;
+      :attr:`co_lnotab` is a string encoding the mapping from byte code offsets to
+      line numbers (for details see the source code of the interpreter);
+      :attr:`co_stacksize` is the required stack size (including local variables);
+      :attr:`co_flags` is an integer encoding a number of flags for the interpreter.
+
+      .. index::
+         single: co_argcount (code object attribute)
+         single: co_code (code object attribute)
+         single: co_consts (code object attribute)
+         single: co_filename (code object attribute)
+         single: co_firstlineno (code object attribute)
+         single: co_flags (code object attribute)
+         single: co_lnotab (code object attribute)
+         single: co_name (code object attribute)
+         single: co_names (code object attribute)
+         single: co_nlocals (code object attribute)
+         single: co_stacksize (code object attribute)
+         single: co_varnames (code object attribute)
+         single: co_cellvars (code object attribute)
+         single: co_freevars (code object attribute)
+
+      .. index:: object: generator
+
+      The following flag bits are defined for :attr:`co_flags`: bit ``0x04`` is set if
+      the function uses the ``*arguments`` syntax to accept an arbitrary number of
+      positional arguments; bit ``0x08`` is set if the function uses the
+      ``**keywords`` syntax to accept arbitrary keyword arguments; bit ``0x20`` is set
+      if the function is a generator.
+
+      Future feature declarations (``from __future__ import division``) also use bits
+      in :attr:`co_flags` to indicate whether a code object was compiled with a
+      particular feature enabled: bit ``0x2000`` is set if the function was compiled
+      with future division enabled; bits ``0x10`` and ``0x1000`` were used in earlier
+      versions of Python.
+
+      Other bits in :attr:`co_flags` are reserved for internal use.
+
+      .. index:: single: documentation string
+
+      If a code object represents a function, the first item in :attr:`co_consts` is
+      the documentation string of the function, or ``None`` if undefined.
+
+   Frame objects
+      .. index:: object: frame
+
+      Frame objects represent execution frames.  They may occur in traceback objects
+      (see below).
+
+      .. index::
+         single: f_back (frame attribute)
+         single: f_code (frame attribute)
+         single: f_globals (frame attribute)
+         single: f_locals (frame attribute)
+         single: f_lasti (frame attribute)
+         single: f_builtins (frame attribute)
+
+      Special read-only attributes: :attr:`f_back` is to the previous stack frame
+      (towards the caller), or ``None`` if this is the bottom stack frame;
+      :attr:`f_code` is the code object being executed in this frame; :attr:`f_locals`
+      is the dictionary used to look up local variables; :attr:`f_globals` is used for
+      global variables; :attr:`f_builtins` is used for built-in (intrinsic) names;
+      :attr:`f_lasti` gives the precise instruction (this is an index into the
+      bytecode string of the code object).
+
+      .. index::
+         single: f_trace (frame attribute)
+         single: f_exc_type (frame attribute)
+         single: f_exc_value (frame attribute)
+         single: f_exc_traceback (frame attribute)
+         single: f_lineno (frame attribute)
+
+      Special writable attributes: :attr:`f_trace`, if not ``None``, is a function
+      called at the start of each source code line (this is used by the debugger);
+      :attr:`f_exc_type`, :attr:`f_exc_value`, :attr:`f_exc_traceback` represent the
+      last exception raised in the parent frame provided another exception was ever
+      raised in the current frame (in all other cases they are None); :attr:`f_lineno`
+      is the current line number of the frame --- writing to this from within a trace
+      function jumps to the given line (only for the bottom-most frame).  A debugger
+      can implement a Jump command (aka Set Next Statement) by writing to f_lineno.
+
+   Traceback objects
+      .. index::
+         object: traceback
+         pair: stack; trace
+         pair: exception; handler
+         pair: execution; stack
+         single: exc_info (in module sys)
+         single: exc_traceback (in module sys)
+         single: last_traceback (in module sys)
+         single: sys.exc_info
+         single: sys.last_traceback
+
+      Traceback objects represent a stack trace of an exception.  A traceback object
+      is created when an exception occurs.  When the search for an exception handler
+      unwinds the execution stack, at each unwound level a traceback object is
+      inserted in front of the current traceback.  When an exception handler is
+      entered, the stack trace is made available to the program. (See section
+      :ref:`try`.) It is accessible as the third item of the
+      tuple returned by ``sys.exc_info()``. When the program contains no suitable
+      handler, the stack trace is written (nicely formatted) to the standard error
+      stream; if the interpreter is interactive, it is also made available to the user
+      as ``sys.last_traceback``.
+
+      .. index::
+         single: tb_next (traceback attribute)
+         single: tb_frame (traceback attribute)
+         single: tb_lineno (traceback attribute)
+         single: tb_lasti (traceback attribute)
+         statement: try
+
+      Special read-only attributes: :attr:`tb_next` is the next level in the stack
+      trace (towards the frame where the exception occurred), or ``None`` if there is
+      no next level; :attr:`tb_frame` points to the execution frame of the current
+      level; :attr:`tb_lineno` gives the line number where the exception occurred;
+      :attr:`tb_lasti` indicates the precise instruction.  The line number and last
+      instruction in the traceback may differ from the line number of its frame object
+      if the exception occurred in a :keyword:`try` statement with no matching except
+      clause or with a finally clause.
+
+   Slice objects
+      .. index:: builtin: slice
+
+      Slice objects are used to represent slices when *extended slice syntax* is used.
+      This is a slice using two colons, or multiple slices or ellipses separated by
+      commas, e.g., ``a[i:j:step]``, ``a[i:j, k:l]``, or ``a[..., i:j]``.  They are
+      also created by the built-in :func:`slice` function.
+
+      .. index::
+         single: start (slice object attribute)
+         single: stop (slice object attribute)
+         single: step (slice object attribute)
+
+      Special read-only attributes: :attr:`start` is the lower bound; :attr:`stop` is
+      the upper bound; :attr:`step` is the step value; each is ``None`` if omitted.
+      These attributes can have any type.
+
+      Slice objects support one method:
+
+
+      .. method:: slice.indices(self, length)
+
+         This method takes a single integer argument *length* and computes information
+         about the extended slice that the slice object would describe if applied to a
+         sequence of *length* items.  It returns a tuple of three integers; respectively
+         these are the *start* and *stop* indices and the *step* or stride length of the
+         slice. Missing or out-of-bounds indices are handled in a manner consistent with
+         regular slices.
+
+         .. versionadded:: 2.3
+
+   Static method objects
+      Static method objects provide a way of defeating the transformation of function
+      objects to method objects described above. A static method object is a wrapper
+      around any other object, usually a user-defined method object. When a static
+      method object is retrieved from a class or a class instance, the object actually
+      returned is the wrapped object, which is not subject to any further
+      transformation. Static method objects are not themselves callable, although the
+      objects they wrap usually are. Static method objects are created by the built-in
+      :func:`staticmethod` constructor.
+
+   Class method objects
+      A class method object, like a static method object, is a wrapper around another
+      object that alters the way in which that object is retrieved from classes and
+      class instances. The behaviour of class method objects upon such retrieval is
+      described above, under "User-defined methods". Class method objects are created
+      by the built-in :func:`classmethod` constructor.
+
+   .. % Internal types
+
+.. % Types
+.. % =========================================================================
+
+
+New-style and classic classes
+=============================
+
+Classes and instances come in two flavors: old-style or classic, and new-style.
+
+Up to Python 2.1, old-style classes were the only flavour available to the user.
+The concept of (old-style) class is unrelated to the concept of type: if *x* is
+an instance of an old-style class, then ``x.__class__`` designates the class of
+*x*, but ``type(x)`` is always ``<type 'instance'>``.  This reflects the fact
+that all old-style instances, independently of their class, are implemented with
+a single built-in type, called ``instance``.
+
+New-style classes were introduced in Python 2.2 to unify classes and types.  A
+new-style class neither more nor less than a user-defined type.  If *x* is an
+instance of a new-style class, then ``type(x)`` is the same as ``x.__class__``.
+
+The major motivation for introducing new-style classes is to provide a unified
+object model with a full meta-model.  It also has a number of immediate
+benefits, like the ability to subclass most built-in types, or the introduction
+of "descriptors", which enable computed properties.
+
+For compatibility reasons, classes are still old-style by default.  New-style
+classes are created by specifying another new-style class (i.e. a type) as a
+parent class, or the "top-level type" :class:`object` if no other parent is
+needed.  The behaviour of new-style classes differs from that of old-style
+classes in a number of important details in addition to what :func:`type`
+returns.  Some of these changes are fundamental to the new object model, like
+the way special methods are invoked.  Others are "fixes" that could not be
+implemented before for compatibility concerns, like the method resolution order
+in case of multiple inheritance.
+
+This manual is not up-to-date with respect to new-style classes.  For now,
+please see http://www.python.org/doc/newstyle.html for more information.
+
+.. index::
+   single: class
+   single: class
+   single: class
+
+The plan is to eventually drop old-style classes, leaving only the semantics of
+new-style classes.  This change will probably only be feasible in Python 3.0.
+new-style classic old-style
+
+.. % =========================================================================
+
+
+.. _specialnames:
+
+Special method names
+====================
+
+.. index::
+   pair: operator; overloading
+   single: __getitem__() (mapping object method)
+
+A class can implement certain operations that are invoked by special syntax
+(such as arithmetic operations or subscripting and slicing) by defining methods
+with special names. This is Python's approach to :dfn:`operator overloading`,
+allowing classes to define their own behavior with respect to language
+operators.  For instance, if a class defines a method named :meth:`__getitem__`,
+and ``x`` is an instance of this class, then ``x[i]`` is equivalent [#]_ to
+``x.__getitem__(i)``.  Except where mentioned, attempts to execute an operation
+raise an exception when no appropriate method is defined.
+
+When implementing a class that emulates any built-in type, it is important that
+the emulation only be implemented to the degree that it makes sense for the
+object being modelled.  For example, some sequences may work well with retrieval
+of individual elements, but extracting a slice may not make sense.  (One example
+of this is the :class:`NodeList` interface in the W3C's Document Object Model.)
+
+
+.. _customization:
+
+Basic customization
+-------------------
+
+
+.. method:: object.__new__(cls[, ...])
+
+   Called to create a new instance of class *cls*.  :meth:`__new__` is a static
+   method (special-cased so you need not declare it as such) that takes the class
+   of which an instance was requested as its first argument.  The remaining
+   arguments are those passed to the object constructor expression (the call to the
+   class).  The return value of :meth:`__new__` should be the new object instance
+   (usually an instance of *cls*).
+
+   Typical implementations create a new instance of the class by invoking the
+   superclass's :meth:`__new__` method using ``super(currentclass,
+   cls).__new__(cls[, ...])`` with appropriate arguments and then modifying the
+   newly-created instance as necessary before returning it.
+
+   If :meth:`__new__` returns an instance of *cls*, then the new instance's
+   :meth:`__init__` method will be invoked like ``__init__(self[, ...])``, where
+   *self* is the new instance and the remaining arguments are the same as were
+   passed to :meth:`__new__`.
+
+   If :meth:`__new__` does not return an instance of *cls*, then the new instance's
+   :meth:`__init__` method will not be invoked.
+
+   :meth:`__new__` is intended mainly to allow subclasses of immutable types (like
+   int, str, or tuple) to customize instance creation.
+
+
+.. method:: object.__init__(self[, ...])
+
+   .. index:: pair: class; constructor
+
+   Called when the instance is created.  The arguments are those passed to the
+   class constructor expression.  If a base class has an :meth:`__init__` method,
+   the derived class's :meth:`__init__` method, if any, must explicitly call it to
+   ensure proper initialization of the base class part of the instance; for
+   example: ``BaseClass.__init__(self, [args...])``.  As a special constraint on
+   constructors, no value may be returned; doing so will cause a :exc:`TypeError`
+   to be raised at runtime.
+
+
+.. method:: object.__del__(self)
+
+   .. index::
+      single: destructor
+      statement: del
+
+   Called when the instance is about to be destroyed.  This is also called a
+   destructor.  If a base class has a :meth:`__del__` method, the derived class's
+   :meth:`__del__` method, if any, must explicitly call it to ensure proper
+   deletion of the base class part of the instance.  Note that it is possible
+   (though not recommended!) for the :meth:`__del__` method to postpone destruction
+   of the instance by creating a new reference to it.  It may then be called at a
+   later time when this new reference is deleted.  It is not guaranteed that
+   :meth:`__del__` methods are called for objects that still exist when the
+   interpreter exits.
+
+   .. note::
+
+      ``del x`` doesn't directly call ``x.__del__()`` --- the former decrements
+      the reference count for ``x`` by one, and the latter is only called when
+      ``x``'s reference count reaches zero.  Some common situations that may
+      prevent the reference count of an object from going to zero include:
+      circular references between objects (e.g., a doubly-linked list or a tree
+      data structure with parent and child pointers); a reference to the object
+      on the stack frame of a function that caught an exception (the traceback
+      stored in ``sys.exc_info()[2]`` keeps the stack frame alive); or a
+      reference to the object on the stack frame that raised an unhandled
+      exception in interactive mode (the traceback stored in
+      ``sys.last_traceback`` keeps the stack frame alive).  The first situation
+      can only be remedied by explicitly breaking the cycles; the latter two
+      situations can be resolved by storing ``None`` in ``sys.last_traceback``.
+      Circular references which are garbage are detected when the option cycle
+      detector is enabled (it's on by default), but can only be cleaned up if
+      there are no Python- level :meth:`__del__` methods involved. Refer to the
+      documentation for the :mod:`gc` module for more information about how
+      :meth:`__del__` methods are handled by the cycle detector, particularly
+      the description of the ``garbage`` value.
+
+   .. warning::
+
+      Due to the precarious circumstances under which :meth:`__del__` methods are
+      invoked, exceptions that occur during their execution are ignored, and a warning
+      is printed to ``sys.stderr`` instead.  Also, when :meth:`__del__` is invoked in
+      response to a module being deleted (e.g., when execution of the program is
+      done), other globals referenced by the :meth:`__del__` method may already have
+      been deleted.  For this reason, :meth:`__del__` methods should do the absolute
+      minimum needed to maintain external invariants.  Starting with version 1.5,
+      Python guarantees that globals whose name begins with a single underscore are
+      deleted from their module before other globals are deleted; if no other
+      references to such globals exist, this may help in assuring that imported
+      modules are still available at the time when the :meth:`__del__` method is
+      called.
+
+
+.. method:: object.__repr__(self)
+
+   .. index:: builtin: repr
+
+   Called by the :func:`repr` built-in function and by string conversions (reverse
+   quotes) to compute the "official" string representation of an object.  If at all
+   possible, this should look like a valid Python expression that could be used to
+   recreate an object with the same value (given an appropriate environment).  If
+   this is not possible, a string of the form ``<...some useful description...>``
+   should be returned.  The return value must be a string object. If a class
+   defines :meth:`__repr__` but not :meth:`__str__`, then :meth:`__repr__` is also
+   used when an "informal" string representation of instances of that class is
+   required.
+
+   .. index::
+      pair: string; conversion
+      pair: reverse; quotes
+      pair: backward; quotes
+      single: back-quotes
+
+   This is typically used for debugging, so it is important that the representation
+   is information-rich and unambiguous.
+
+
+.. method:: object.__str__(self)
+
+   .. index::
+      builtin: str
+      statement: print
+
+   Called by the :func:`str` built-in function and by the :keyword:`print`
+   statement to compute the "informal" string representation of an object.  This
+   differs from :meth:`__repr__` in that it does not have to be a valid Python
+   expression: a more convenient or concise representation may be used instead.
+   The return value must be a string object.
+
+
+.. method:: object.__lt__(self, other)
+            object.__le__(self, other)
+            object.__eq__(self, other)
+            object.__ne__(self, other)
+            object.__gt__(self, other)
+            object.__ge__(self, other)
+
+   .. versionadded:: 2.1
+
+   These are the so-called "rich comparison" methods, and are called for comparison
+   operators in preference to :meth:`__cmp__` below. The correspondence between
+   operator symbols and method names is as follows: ``x<y`` calls ``x.__lt__(y)``,
+   ``x<=y`` calls ``x.__le__(y)``, ``x==y`` calls ``x.__eq__(y)``, ``x!=y`` calls
+   ``x.__ne__(y)``, ``x>y`` calls ``x.__gt__(y)``, and ``x>=y`` calls
+   ``x.__ge__(y)``.
+
+   A rich comparison method may return the singleton ``NotImplemented`` if it does
+   not implement the operation for a given pair of arguments. By convention,
+   ``False`` and ``True`` are returned for a successful comparison. However, these
+   methods can return any value, so if the comparison operator is used in a Boolean
+   context (e.g., in the condition of an ``if`` statement), Python will call
+   :func:`bool` on the value to determine if the result is true or false.
+
+   There are no implied relationships among the comparison operators. The truth of
+   ``x==y`` does not imply that ``x!=y`` is false.  Accordingly, when defining
+   :meth:`__eq__`, one should also define :meth:`__ne__` so that the operators will
+   behave as expected.
+
+   There are no reflected (swapped-argument) versions of these methods (to be used
+   when the left argument does not support the operation but the right argument
+   does); rather, :meth:`__lt__` and :meth:`__gt__` are each other's reflection,
+   :meth:`__le__` and :meth:`__ge__` are each other's reflection, and
+   :meth:`__eq__` and :meth:`__ne__` are their own reflection.
+
+   Arguments to rich comparison methods are never coerced.
+
+
+.. method:: object.__cmp__(self, other)
+
+   .. index::
+      builtin: cmp
+      single: comparisons
+
+   Called by comparison operations if rich comparison (see above) is not defined.
+   Should return a negative integer if ``self < other``, zero if ``self == other``,
+   a positive integer if ``self > other``.  If no :meth:`__cmp__`, :meth:`__eq__`
+   or :meth:`__ne__` operation is defined, class instances are compared by object
+   identity ("address").  See also the description of :meth:`__hash__` for some
+   important notes on creating objects which support custom comparison operations
+   and are usable as dictionary keys. (Note: the restriction that exceptions are
+   not propagated by :meth:`__cmp__` has been removed since Python 1.5.)
+
+
+.. method:: object.__rcmp__(self, other)
+
+   .. versionchanged:: 2.1
+      No longer supported.
+
+
+.. method:: object.__hash__(self)
+
+   .. index::
+      object: dictionary
+      builtin: hash
+
+   Called for the key object for dictionary  operations, and by the built-in
+   function :func:`hash`.  Should return a 32-bit integer usable as a hash value
+   for dictionary operations.  The only required property is that objects which
+   compare equal have the same hash value; it is advised to somehow mix together
+   (e.g., using exclusive or) the hash values for the components of the object that
+   also play a part in comparison of objects.  If a class does not define a
+   :meth:`__cmp__` method it should not define a :meth:`__hash__` operation either;
+   if it defines :meth:`__cmp__` or :meth:`__eq__` but not :meth:`__hash__`, its
+   instances will not be usable as dictionary keys.  If a class defines mutable
+   objects and implements a :meth:`__cmp__` or :meth:`__eq__` method, it should not
+   implement :meth:`__hash__`, since the dictionary implementation requires that a
+   key's hash value is immutable (if the object's hash value changes, it will be in
+   the wrong hash bucket).
+
+   .. versionchanged:: 2.5
+      :meth:`__hash__` may now also return a long integer object; the 32-bit integer
+      is then derived from the hash of that object.
+
+   .. index:: single: __cmp__() (object method)
+
+
+.. method:: object.__bool__(self)
+
+   .. index:: single: __len__() (mapping object method)
+
+   Called to implement truth value testing, and the built-in operation ``bool()``;
+   should return ``False`` or ``True``. When this method is not defined,
+   :meth:`__len__` is called, if it is defined (see below) and ``True`` is returned
+   when the length is not zero.  If a class defines neither :meth:`__len__` nor
+   :meth:`__bool__`, all its instances are considered true.
+
+
+.. method:: object.__unicode__(self)
+
+   .. index:: builtin: unicode
+
+   Called to implement :func:`unicode` builtin; should return a Unicode object.
+   When this method is not defined, string conversion is attempted, and the result
+   of string conversion is converted to Unicode using the system default encoding.
+
+
+.. _attribute-access:
+
+Customizing attribute access
+----------------------------
+
+The following methods can be defined to customize the meaning of attribute
+access (use of, assignment to, or deletion of ``x.name``) for class instances.
+
+
+.. method:: object.__getattr__(self, name)
+
+   Called when an attribute lookup has not found the attribute in the usual places
+   (i.e. it is not an instance attribute nor is it found in the class tree for
+   ``self``).  ``name`` is the attribute name. This method should return the
+   (computed) attribute value or raise an :exc:`AttributeError` exception.
+
+   .. index:: single: __setattr__() (object method)
+
+   Note that if the attribute is found through the normal mechanism,
+   :meth:`__getattr__` is not called.  (This is an intentional asymmetry between
+   :meth:`__getattr__` and :meth:`__setattr__`.) This is done both for efficiency
+   reasons and because otherwise :meth:`__setattr__` would have no way to access
+   other attributes of the instance.  Note that at least for instance variables,
+   you can fake total control by not inserting any values in the instance attribute
+   dictionary (but instead inserting them in another object).  See the
+   :meth:`__getattribute__` method below for a way to actually get total control in
+   new-style classes.
+
+
+.. method:: object.__setattr__(self, name, value)
+
+   Called when an attribute assignment is attempted.  This is called instead of the
+   normal mechanism (i.e. store the value in the instance dictionary).  *name* is
+   the attribute name, *value* is the value to be assigned to it.
+
+   .. index:: single: __dict__ (instance attribute)
+
+   If :meth:`__setattr__` wants to assign to an instance attribute, it should not
+   simply execute ``self.name = value`` --- this would cause a recursive call to
+   itself.  Instead, it should insert the value in the dictionary of instance
+   attributes, e.g., ``self.__dict__[name] = value``.  For new-style classes,
+   rather than accessing the instance dictionary, it should call the base class
+   method with the same name, for example, ``object.__setattr__(self, name,
+   value)``.
+
+
+.. method:: object.__delattr__(self, name)
+
+   Like :meth:`__setattr__` but for attribute deletion instead of assignment.  This
+   should only be implemented if ``del obj.name`` is meaningful for the object.
+
+
+.. _new-style-attribute-access:
+
+More attribute access for new-style classes
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+The following methods only apply to new-style classes.
+
+
+.. method:: object.__getattribute__(self, name)
+
+   Called unconditionally to implement attribute accesses for instances of the
+   class. If the class also defines :meth:`__getattr__`, the latter will not be
+   called unless :meth:`__getattribute__` either calls it explicitly or raises an
+   :exc:`AttributeError`. This method should return the (computed) attribute value
+   or raise an :exc:`AttributeError` exception. In order to avoid infinite
+   recursion in this method, its implementation should always call the base class
+   method with the same name to access any attributes it needs, for example,
+   ``object.__getattribute__(self, name)``.
+
+
+.. _descriptors:
+
+Implementing Descriptors
+^^^^^^^^^^^^^^^^^^^^^^^^
+
+The following methods only apply when an instance of the class containing the
+method (a so-called *descriptor* class) appears in the class dictionary of
+another new-style class, known as the *owner* class. In the examples below, "the
+attribute" refers to the attribute whose name is the key of the property in the
+owner class' ``__dict__``.  Descriptors can only be implemented as new-style
+classes themselves.
+
+
+.. method:: object.__get__(self, instance, owner)
+
+   Called to get the attribute of the owner class (class attribute access) or of an
+   instance of that class (instance attribute access). *owner* is always the owner
+   class, while *instance* is the instance that the attribute was accessed through,
+   or ``None`` when the attribute is accessed through the *owner*.  This method
+   should return the (computed) attribute value or raise an :exc:`AttributeError`
+   exception.
+
+
+.. method:: object.__set__(self, instance, value)
+
+   Called to set the attribute on an instance *instance* of the owner class to a
+   new value, *value*.
+
+
+.. method:: object.__delete__(self, instance)
+
+   Called to delete the attribute on an instance *instance* of the owner class.
+
+
+.. _descriptor-invocation:
+
+Invoking Descriptors
+^^^^^^^^^^^^^^^^^^^^
+
+In general, a descriptor is an object attribute with "binding behavior", one
+whose attribute access has been overridden by methods in the descriptor
+protocol:  :meth:`__get__`, :meth:`__set__`, and :meth:`__delete__`. If any of
+those methods are defined for an object, it is said to be a descriptor.
+
+The default behavior for attribute access is to get, set, or delete the
+attribute from an object's dictionary. For instance, ``a.x`` has a lookup chain
+starting with ``a.__dict__['x']``, then ``type(a).__dict__['x']``, and
+continuing through the base classes of ``type(a)`` excluding metaclasses.
+
+However, if the looked-up value is an object defining one of the descriptor
+methods, then Python may override the default behavior and invoke the descriptor
+method instead.  Where this occurs in the precedence chain depends on which
+descriptor methods were defined and how they were called.  Note that descriptors
+are only invoked for new style objects or classes (ones that subclass
+:class:`object()` or :class:`type()`).
+
+The starting point for descriptor invocation is a binding, ``a.x``. How the
+arguments are assembled depends on ``a``:
+
+Direct Call
+   The simplest and least common call is when user code directly invokes a
+   descriptor method:    ``x.__get__(a)``.
+
+Instance Binding
+   If binding to a new-style object instance, ``a.x`` is transformed into the call:
+   ``type(a).__dict__['x'].__get__(a, type(a))``.
+
+Class Binding
+   If binding to a new-style class, ``A.x`` is transformed into the call:
+   ``A.__dict__['x'].__get__(None, A)``.
+
+Super Binding
+   If ``a`` is an instance of :class:`super`, then the binding ``super(B,
+   obj).m()`` searches ``obj.__class__.__mro__`` for the base class ``A``
+   immediately preceding ``B`` and then invokes the descriptor with the call:
+   ``A.__dict__['m'].__get__(obj, A)``.
+
+For instance bindings, the precedence of descriptor invocation depends on the
+which descriptor methods are defined.  Data descriptors define both
+:meth:`__get__` and :meth:`__set__`.  Non-data descriptors have just the
+:meth:`__get__` method.  Data descriptors always override a redefinition in an
+instance dictionary.  In contrast, non-data descriptors can be overridden by
+instances.
+
+Python methods (including :func:`staticmethod` and :func:`classmethod`) are
+implemented as non-data descriptors.  Accordingly, instances can redefine and
+override methods.  This allows individual instances to acquire behaviors that
+differ from other instances of the same class.
+
+The :func:`property` function is implemented as a data descriptor. Accordingly,
+instances cannot override the behavior of a property.
+
+
+.. _slots:
+
+__slots__
+^^^^^^^^^
+
+By default, instances of both old and new-style classes have a dictionary for
+attribute storage.  This wastes space for objects having very few instance
+variables.  The space consumption can become acute when creating large numbers
+of instances.
+
+The default can be overridden by defining *__slots__* in a new-style class
+definition.  The *__slots__* declaration takes a sequence of instance variables
+and reserves just enough space in each instance to hold a value for each
+variable.  Space is saved because *__dict__* is not created for each instance.
+
+
+.. data:: __slots__
+
+   This class variable can be assigned a string, iterable, or sequence of strings
+   with variable names used by instances.  If defined in a new-style class,
+   *__slots__* reserves space for the declared variables and prevents the automatic
+   creation of *__dict__* and *__weakref__* for each instance.
+
+   .. versionadded:: 2.2
+
+Notes on using *__slots__*
+
+* Without a *__dict__* variable, instances cannot be assigned new variables not
+  listed in the *__slots__* definition.  Attempts to assign to an unlisted
+  variable name raises :exc:`AttributeError`. If dynamic assignment of new
+  variables is desired, then add ``'__dict__'`` to the sequence of strings in the
+  *__slots__* declaration.
+
+  .. versionchanged:: 2.3
+     Previously, adding ``'__dict__'`` to the *__slots__* declaration would not
+     enable the assignment of new attributes not specifically listed in the sequence
+     of instance variable names.
+
+* Without a *__weakref__* variable for each instance, classes defining
+  *__slots__* do not support weak references to its instances. If weak reference
+  support is needed, then add ``'__weakref__'`` to the sequence of strings in the
+  *__slots__* declaration.
+
+  .. versionchanged:: 2.3
+     Previously, adding ``'__weakref__'`` to the *__slots__* declaration would not
+     enable support for weak references.
+
+* *__slots__* are implemented at the class level by creating descriptors
+  (:ref:`descriptors`) for each variable name.  As a result, class attributes
+  cannot be used to set default values for instance variables defined by
+  *__slots__*; otherwise, the class attribute would overwrite the descriptor
+  assignment.
+
+* If a class defines a slot also defined in a base class, the instance variable
+  defined by the base class slot is inaccessible (except by retrieving its
+  descriptor directly from the base class). This renders the meaning of the
+  program undefined.  In the future, a check may be added to prevent this.
+
+* The action of a *__slots__* declaration is limited to the class where it is
+  defined.  As a result, subclasses will have a *__dict__* unless they also define
+  *__slots__*.
+
+* *__slots__* do not work for classes derived from "variable-length" built-in
+  types such as :class:`long`, :class:`str` and :class:`tuple`.
+
+* Any non-string iterable may be assigned to *__slots__*. Mappings may also be
+  used; however, in the future, special meaning may be assigned to the values
+  corresponding to each key.
+
+* *__class__* assignment works only if both classes have the same *__slots__*.
+
+  .. versionchanged:: 2.6
+     Previously, *__class__* assignment raised an error if either new or old class
+     had *__slots__*.
+
+
+.. _metaclasses:
+
+Customizing class creation
+--------------------------
+
+By default, new-style classes are constructed using :func:`type`. A class
+definition is read into a separate namespace and the value of class name is
+bound to the result of ``type(name, bases, dict)``.
+
+When the class definition is read, if *__metaclass__* is defined then the
+callable assigned to it will be called instead of :func:`type`. The allows
+classes or functions to be written which monitor or alter the class creation
+process:
+
+* Modifying the class dictionary prior to the class being created.
+
+* Returning an instance of another class -- essentially performing the role of a
+  factory function.
+
+
+.. data:: __metaclass__
+
+   This variable can be any callable accepting arguments for ``name``, ``bases``,
+   and ``dict``.  Upon class creation, the callable is used instead of the built-in
+   :func:`type`.
+
+   .. versionadded:: 2.2
+
+The appropriate metaclass is determined by the following precedence rules:
+
+* If ``dict['__metaclass__']`` exists, it is used.
+
+* Otherwise, if there is at least one base class, its metaclass is used (this
+  looks for a *__class__* attribute first and if not found, uses its type).
+
+* Otherwise, if a global variable named __metaclass__ exists, it is used.
+
+* Otherwise, the old-style, classic metaclass (types.ClassType) is used.
+
+The potential uses for metaclasses are boundless. Some ideas that have been
+explored including logging, interface checking, automatic delegation, automatic
+property creation, proxies, frameworks, and automatic resource
+locking/synchronization.
+
+
+.. _callable-types:
+
+Emulating callable objects
+--------------------------
+
+
+.. method:: object.__call__(self[, args...])
+
+   .. index:: pair: call; instance
+
+   Called when the instance is "called" as a function; if this method is defined,
+   ``x(arg1, arg2, ...)`` is a shorthand for ``x.__call__(arg1, arg2, ...)``.
+
+
+.. _sequence-types:
+
+Emulating container types
+-------------------------
+
+The following methods can be defined to implement container objects.  Containers
+usually are sequences (such as lists or tuples) or mappings (like dictionaries),
+but can represent other containers as well.  The first set of methods is used
+either to emulate a sequence or to emulate a mapping; the difference is that for
+a sequence, the allowable keys should be the integers *k* for which ``0 <= k <
+N`` where *N* is the length of the sequence, or slice objects, which define a
+range of items. (For backwards compatibility, the method :meth:`__getslice__`
+(see below) can also be defined to handle simple, but not extended slices.) It
+is also recommended that mappings provide the methods :meth:`keys`,
+:meth:`values`, :meth:`items`, :meth:`has_key`, :meth:`get`, :meth:`clear`,
+:meth:`setdefault`, :meth:`iterkeys`, :meth:`itervalues`, :meth:`iteritems`,
+:meth:`pop`, :meth:`popitem`, :meth:`copy`, and :meth:`update` behaving similar
+to those for Python's standard dictionary objects.  The :mod:`UserDict` module
+provides a :class:`DictMixin` class to help create those methods from a base set
+of :meth:`__getitem__`, :meth:`__setitem__`, :meth:`__delitem__`, and
+:meth:`keys`. Mutable sequences should provide methods :meth:`append`,
+:meth:`count`, :meth:`index`, :meth:`extend`, :meth:`insert`, :meth:`pop`,
+:meth:`remove`, :meth:`reverse` and :meth:`sort`, like Python standard list
+objects.  Finally, sequence types should implement addition (meaning
+concatenation) and multiplication (meaning repetition) by defining the methods
+:meth:`__add__`, :meth:`__radd__`, :meth:`__iadd__`, :meth:`__mul__`,
+:meth:`__rmul__` and :meth:`__imul__` described below; they should not define
+other numerical operators.  It is recommended that both mappings and sequences
+implement the :meth:`__contains__` method to allow efficient use of the ``in``
+operator; for mappings, ``in`` should be equivalent of :meth:`has_key`; for
+sequences, it should search through the values.  It is further recommended that
+both mappings and sequences implement the :meth:`__iter__` method to allow
+efficient iteration through the container; for mappings, :meth:`__iter__` should
+be the same as :meth:`iterkeys`; for sequences, it should iterate through the
+values.
+
+
+.. method:: object.__len__(self)
+
+   .. index::
+      builtin: len
+      single: __bool__() (object method)
+
+   Called to implement the built-in function :func:`len`.  Should return the length
+   of the object, an integer ``>=`` 0.  Also, an object that doesn't define a
+   :meth:`__bool__` method and whose :meth:`__len__` method returns zero is
+   considered to be false in a Boolean context.
+
+
+.. method:: object.__getitem__(self, key)
+
+   .. index:: object: slice
+
+   Called to implement evaluation of ``self[key]``. For sequence types, the
+   accepted keys should be integers and slice objects.  Note that the special
+   interpretation of negative indexes (if the class wishes to emulate a sequence
+   type) is up to the :meth:`__getitem__` method. If *key* is of an inappropriate
+   type, :exc:`TypeError` may be raised; if of a value outside the set of indexes
+   for the sequence (after any special interpretation of negative values),
+   :exc:`IndexError` should be raised. For mapping types, if *key* is missing (not
+   in the container), :exc:`KeyError` should be raised.
+
+   .. note::
+
+      :keyword:`for` loops expect that an :exc:`IndexError` will be raised for illegal
+      indexes to allow proper detection of the end of the sequence.
+
+
+.. method:: object.__setitem__(self, key, value)
+
+   Called to implement assignment to ``self[key]``.  Same note as for
+   :meth:`__getitem__`.  This should only be implemented for mappings if the
+   objects support changes to the values for keys, or if new keys can be added, or
+   for sequences if elements can be replaced.  The same exceptions should be raised
+   for improper *key* values as for the :meth:`__getitem__` method.
+
+
+.. method:: object.__delitem__(self, key)
+
+   Called to implement deletion of ``self[key]``.  Same note as for
+   :meth:`__getitem__`.  This should only be implemented for mappings if the
+   objects support removal of keys, or for sequences if elements can be removed
+   from the sequence.  The same exceptions should be raised for improper *key*
+   values as for the :meth:`__getitem__` method.
+
+
+.. method:: object.__iter__(self)
+
+   This method is called when an iterator is required for a container. This method
+   should return a new iterator object that can iterate over all the objects in the
+   container.  For mappings, it should iterate over the keys of the container, and
+   should also be made available as the method :meth:`iterkeys`.
+
+   Iterator objects also need to implement this method; they are required to return
+   themselves.  For more information on iterator objects, see :ref:`typeiter`.
+
+The membership test operators (:keyword:`in` and :keyword:`not in`) are normally
+implemented as an iteration through a sequence.  However, container objects can
+supply the following special method with a more efficient implementation, which
+also does not require the object be a sequence.
+
+
+.. method:: object.__contains__(self, item)
+
+   Called to implement membership test operators.  Should return true if *item* is
+   in *self*, false otherwise.  For mapping objects, this should consider the keys
+   of the mapping rather than the values or the key-item pairs.
+
+
+.. _sequence-methods:
+
+Additional methods for emulation of sequence types
+--------------------------------------------------
+
+The following optional methods can be defined to further emulate sequence
+objects.  Immutable sequences methods should at most only define
+:meth:`__getslice__`; mutable sequences might define all three methods.
+
+
+.. method:: object.__getslice__(self, i, j)
+
+   .. deprecated:: 2.0
+      Support slice objects as parameters to the :meth:`__getitem__` method.
+
+   Called to implement evaluation of ``self[i:j]``. The returned object should be
+   of the same type as *self*.  Note that missing *i* or *j* in the slice
+   expression are replaced by zero or ``sys.maxint``, respectively.  If negative
+   indexes are used in the slice, the length of the sequence is added to that
+   index. If the instance does not implement the :meth:`__len__` method, an
+   :exc:`AttributeError` is raised. No guarantee is made that indexes adjusted this
+   way are not still negative.  Indexes which are greater than the length of the
+   sequence are not modified. If no :meth:`__getslice__` is found, a slice object
+   is created instead, and passed to :meth:`__getitem__` instead.
+
+
+.. method:: object.__setslice__(self, i, j, sequence)
+
+   Called to implement assignment to ``self[i:j]``. Same notes for *i* and *j* as
+   for :meth:`__getslice__`.
+
+   This method is deprecated. If no :meth:`__setslice__` is found, or for extended
+   slicing of the form ``self[i:j:k]``, a slice object is created, and passed to
+   :meth:`__setitem__`, instead of :meth:`__setslice__` being called.
+
+
+.. method:: object.__delslice__(self, i, j)
+
+   Called to implement deletion of ``self[i:j]``. Same notes for *i* and *j* as for
+   :meth:`__getslice__`. This method is deprecated. If no :meth:`__delslice__` is
+   found, or for extended slicing of the form ``self[i:j:k]``, a slice object is
+   created, and passed to :meth:`__delitem__`, instead of :meth:`__delslice__`
+   being called.
+
+Notice that these methods are only invoked when a single slice with a single
+colon is used, and the slice method is available.  For slice operations
+involving extended slice notation, or in absence of the slice methods,
+:meth:`__getitem__`, :meth:`__setitem__` or :meth:`__delitem__` is called with a
+slice object as argument.
+
+The following example demonstrate how to make your program or module compatible
+with earlier versions of Python (assuming that methods :meth:`__getitem__`,
+:meth:`__setitem__` and :meth:`__delitem__` support slice objects as
+arguments)::
+
+   class MyClass:
+       ...
+       def __getitem__(self, index):
+           ...
+       def __setitem__(self, index, value):
+           ...
+       def __delitem__(self, index):
+           ...
+
+       if sys.version_info < (2, 0):
+           # They won't be defined if version is at least 2.0 final
+
+           def __getslice__(self, i, j):
+               return self[max(0, i):max(0, j):]
+           def __setslice__(self, i, j, seq):
+               self[max(0, i):max(0, j):] = seq
+           def __delslice__(self, i, j):
+               del self[max(0, i):max(0, j):]
+       ...
+
+Note the calls to :func:`max`; these are necessary because of the handling of
+negative indices before the :meth:`__\*slice__` methods are called.  When
+negative indexes are used, the :meth:`__\*item__` methods receive them as
+provided, but the :meth:`__\*slice__` methods get a "cooked" form of the index
+values.  For each negative index value, the length of the sequence is added to
+the index before calling the method (which may still result in a negative
+index); this is the customary handling of negative indexes by the built-in
+sequence types, and the :meth:`__\*item__` methods are expected to do this as
+well.  However, since they should already be doing that, negative indexes cannot
+be passed in; they must be constrained to the bounds of the sequence before
+being passed to the :meth:`__\*item__` methods. Calling ``max(0, i)``
+conveniently returns the proper value.
+
+
+.. _numeric-types:
+
+Emulating numeric types
+-----------------------
+
+The following methods can be defined to emulate numeric objects. Methods
+corresponding to operations that are not supported by the particular kind of
+number implemented (e.g., bitwise operations for non-integral numbers) should be
+left undefined.
+
+
+.. method:: object.__add__(self, other)
+            object.__sub__(self, other)
+            object.__mul__(self, other)
+            object.__floordiv__(self, other)
+            object.__mod__(self, other)
+            object.__divmod__(self, other)
+            object.__pow__(self, other[, modulo])
+            object.__lshift__(self, other)
+            object.__rshift__(self, other)
+            object.__and__(self, other)
+            object.__xor__(self, other)
+            object.__or__(self, other)
+
+   .. index::
+      builtin: divmod
+      builtin: pow
+      builtin: pow
+
+   These methods are called to implement the binary arithmetic operations (``+``,
+   ``-``, ``*``, ``//``, ``%``, :func:`divmod`, :func:`pow`, ``**``, ``<<``,
+   ``>>``, ``&``, ``^``, ``|``).  For instance, to evaluate the expression
+   *x*``+``*y*, where *x* is an instance of a class that has an :meth:`__add__`
+   method, ``x.__add__(y)`` is called.  The :meth:`__divmod__` method should be the
+   equivalent to using :meth:`__floordiv__` and :meth:`__mod__`; it should not be
+   related to :meth:`__truediv__` (described below).  Note that :meth:`__pow__`
+   should be defined to accept an optional third argument if the ternary version of
+   the built-in :func:`pow` function is to be supported.
+
+   If one of those methods does not support the operation with the supplied
+   arguments, it should return ``NotImplemented``.
+
+
+.. method:: object.__div__(self, other)
+            object.__truediv__(self, other)
+
+   The division operator (``/``) is implemented by these methods.  The
+   :meth:`__truediv__` method is used when ``__future__.division`` is in effect,
+   otherwise :meth:`__div__` is used.  If only one of these two methods is defined,
+   the object will not support division in the alternate context; :exc:`TypeError`
+   will be raised instead.
+
+
+.. method:: object.__radd__(self, other)
+            object.__rsub__(self, other)
+            object.__rmul__(self, other)
+            object.__rdiv__(self, other)
+            object.__rtruediv__(self, other)
+            object.__rfloordiv__(self, other)
+            object.__rmod__(self, other)
+            object.__rdivmod__(self, other)
+            object.__rpow__(self, other)
+            object.__rlshift__(self, other)
+            object.__rrshift__(self, other)
+            object.__rand__(self, other)
+            object.__rxor__(self, other)
+            object.__ror__(self, other)
+
+   .. index::
+      builtin: divmod
+      builtin: pow
+
+   These methods are called to implement the binary arithmetic operations (``+``,
+   ``-``, ``*``, ``/``, ``%``, :func:`divmod`, :func:`pow`, ``**``, ``<<``, ``>>``,
+   ``&``, ``^``, ``|``) with reflected (swapped) operands.  These functions are
+   only called if the left operand does not support the corresponding operation and
+   the operands are of different types. [#]_ For instance, to evaluate the
+   expression *x*``-``*y*, where *y* is an instance of a class that has an
+   :meth:`__rsub__` method, ``y.__rsub__(x)`` is called if ``x.__sub__(y)`` returns
+   *NotImplemented*.
+
+   .. index:: builtin: pow
+
+   Note that ternary :func:`pow` will not try calling :meth:`__rpow__` (the
+   coercion rules would become too complicated).
+
+   .. note::
+
+      If the right operand's type is a subclass of the left operand's type and that
+      subclass provides the reflected method for the operation, this method will be
+      called before the left operand's non-reflected method.  This behavior allows
+      subclasses to override their ancestors' operations.
+
+
+.. method:: object.__iadd__(self, other)
+            object.__isub__(self, other)
+            object.__imul__(self, other)
+            object.__idiv__(self, other)
+            object.__itruediv__(self, other)
+            object.__ifloordiv__(self, other)
+            object.__imod__(self, other)
+            object.__ipow__(self, other[, modulo])
+            object.__ilshift__(self, other)
+            object.__irshift__(self, other)
+            object.__iand__(self, other)
+            object.__ixor__(self, other)
+            object.__ior__(self, other)
+
+   These methods are called to implement the augmented arithmetic operations
+   (``+=``, ``-=``, ``*=``, ``/=``, ``//=``, ``%=``, ``**=``, ``<<=``, ``>>=``,
+   ``&=``, ``^=``, ``|=``).  These methods should attempt to do the operation
+   in-place (modifying *self*) and return the result (which could be, but does
+   not have to be, *self*).  If a specific method is not defined, the augmented
+   operation falls back to the normal methods.  For instance, to evaluate the
+   expression *x*``+=``*y*, where *x* is an instance of a class that has an
+   :meth:`__iadd__` method, ``x.__iadd__(y)`` is called.  If *x* is an instance
+   of a class that does not define a :meth:`__iadd__` method, ``x.__add__(y)``
+   and ``y.__radd__(x)`` are considered, as with the evaluation of *x*``+``*y*.
+
+
+.. method:: object.__neg__(self)
+            object.__pos__(self)
+            object.__abs__(self)
+            object.__invert__(self)
+
+   .. index:: builtin: abs
+
+   Called to implement the unary arithmetic operations (``-``, ``+``, :func:`abs`
+   and ``~``).
+
+
+.. method:: object.__complex__(self)
+            object.__int__(self)
+            object.__long__(self)
+            object.__float__(self)
+
+   .. index::
+      builtin: complex
+      builtin: int
+      builtin: long
+      builtin: float
+
+   Called to implement the built-in functions :func:`complex`, :func:`int`,
+   :func:`long`, and :func:`float`.  Should return a value of the appropriate type.
+
+
+.. method:: object.__index__(self)
+
+   Called to implement :func:`operator.index`.  Also called whenever Python needs
+   an integer object (such as in slicing, or in the built-in :func:`bin`,
+   :func:`hex` and :func:`oct` functions). Must return an integer (int or long).
+
+   .. versionadded:: 2.5
+
+
+.. _context-managers:
+
+With Statement Context Managers
+-------------------------------
+
+.. versionadded:: 2.5
+
+A :dfn:`context manager` is an object that defines the runtime context to be
+established when executing a :keyword:`with` statement. The context manager
+handles the entry into, and the exit from, the desired runtime context for the
+execution of the block of code.  Context managers are normally invoked using the
+:keyword:`with` statement (described in section :ref:`with`), but can also be
+used by directly invoking their methods.
+
+.. index::
+   statement: with
+   single: context manager
+
+Typical uses of context managers include saving and restoring various kinds of
+global state, locking and unlocking resources, closing opened files, etc.
+
+For more information on context managers, see :ref:`typecontextmanager`.
+
+
+.. method:: object.__enter__(self)
+
+   Enter the runtime context related to this object. The :keyword:`with` statement
+   will bind this method's return value to the target(s) specified in the
+   :keyword:`as` clause of the statement, if any.
+
+
+.. method:: object.__exit__(self, exc_type, exc_value, traceback)
+
+   Exit the runtime context related to this object. The parameters describe the
+   exception that caused the context to be exited. If the context was exited
+   without an exception, all three arguments will be :const:`None`.
+
+   If an exception is supplied, and the method wishes to suppress the exception
+   (i.e., prevent it from being propagated), it should return a true value.
+   Otherwise, the exception will be processed normally upon exit from this method.
+
+   Note that :meth:`__exit__` methods should not reraise the passed-in exception;
+   this is the caller's responsibility.
+
+
+.. seealso::
+
+   :pep:`0343` - The "with" statement
+      The specification, background, and examples for the Python :keyword:`with`
+      statement.
+
+.. rubric:: Footnotes
+
+.. [#] Since Python 2.2, a gradual merging of types and classes has been started that
+   makes this and a few other assertions made in this manual not 100% accurate and
+   complete: for example, it *is* now possible in some cases to change an object's
+   type, under certain controlled conditions.  Until this manual undergoes
+   extensive revision, it must now be taken as authoritative only regarding
+   "classic classes", that are still the default, for compatibility purposes, in
+   Python 2.2 and 2.3.  For more information, see
+   http://www.python.org/doc/newstyle.html.
+
+.. [#] This, and other statements, are only roughly true for instances of new-style
+   classes.
+
+.. [#] For operands of the same type, it is assumed that if the non-reflected method
+   (such as :meth:`__add__`) fails the operation is not supported, which is why the
+   reflected method is not called.
+
diff --git a/Doc/reference/executionmodel.rst b/Doc/reference/executionmodel.rst
new file mode 100644
index 0000000..27802c8
--- /dev/null
+++ b/Doc/reference/executionmodel.rst
@@ -0,0 +1,232 @@
+
+.. _execmodel:
+
+***************
+Execution model
+***************
+
+.. index:: single: execution model
+
+
+.. _naming:
+
+Naming and binding
+==================
+
+.. index::
+   pair: code; block
+   single: namespace
+   single: scope
+
+.. index::
+   single: name
+   pair: binding; name
+
+:dfn:`Names` refer to objects.  Names are introduced by name binding operations.
+Each occurrence of a name in the program text refers to the :dfn:`binding` of
+that name established in the innermost function block containing the use.
+
+.. index:: single: block
+
+A :dfn:`block` is a piece of Python program text that is executed as a unit.
+The following are blocks: a module, a function body, and a class definition.
+Each command typed interactively is a block.  A script file (a file given as
+standard input to the interpreter or specified on the interpreter command line
+the first argument) is a code block.  A script command (a command specified on
+the interpreter command line with the '**-c**' option) is a code block.  The string
+argument passed to the built-in functions :func:`eval` and :func:`exec` is a
+code block. The expression read and evaluated by the built-in function
+:func:`input` is a code block.
+
+.. index:: pair: execution; frame
+
+A code block is executed in an :dfn:`execution frame`.  A frame contains some
+administrative information (used for debugging) and determines where and how
+execution continues after the code block's execution has completed.
+
+.. index:: single: scope
+
+A :dfn:`scope` defines the visibility of a name within a block.  If a local
+variable is defined in a block, its scope includes that block.  If the
+definition occurs in a function block, the scope extends to any blocks contained
+within the defining one, unless a contained block introduces a different binding
+for the name.  The scope of names defined in a class block is limited to the
+class block; it does not extend to the code blocks of methods.
+
+.. index:: single: environment
+
+When a name is used in a code block, it is resolved using the nearest enclosing
+scope.  The set of all such scopes visible to a code block is called the block's
+:dfn:`environment`.
+
+.. index:: pair: free; variable
+
+If a name is bound in a block, it is a local variable of that block. If a name
+is bound at the module level, it is a global variable.  (The variables of the
+module code block are local and global.)  If a variable is used in a code block
+but not defined there, it is a :dfn:`free variable`.
+
+.. index::
+   single: NameError (built-in exception)
+   single: UnboundLocalError
+
+When a name is not found at all, a :exc:`NameError` exception is raised.  If the
+name refers to a local variable that has not been bound, a
+:exc:`UnboundLocalError` exception is raised.  :exc:`UnboundLocalError` is a
+subclass of :exc:`NameError`.
+
+.. index:: statement: from
+
+The following constructs bind names: formal parameters to functions,
+:keyword:`import` statements, class and function definitions (these bind the
+class or function name in the defining block), and targets that are identifiers
+if occurring in an assignment, :keyword:`for` loop header, or in the second
+position of an :keyword:`except` clause header.  The :keyword:`import` statement
+of the form "``from ...import *``" binds all names defined in the imported
+module, except those beginning with an underscore.  This form may only be used
+at the module level.
+
+A target occurring in a :keyword:`del` statement is also considered bound for
+this purpose (though the actual semantics are to unbind the name).  It is
+illegal to unbind a name that is referenced by an enclosing scope; the compiler
+will report a :exc:`SyntaxError`.
+
+Each assignment or import statement occurs within a block defined by a class or
+function definition or at the module level (the top-level code block).
+
+If a name binding operation occurs anywhere within a code block, all uses of the
+name within the block are treated as references to the current block.  This can
+lead to errors when a name is used within a block before it is bound. This rule
+is subtle.  Python lacks declarations and allows name binding operations to
+occur anywhere within a code block.  The local variables of a code block can be
+determined by scanning the entire text of the block for name binding operations.
+
+If the global statement occurs within a block, all uses of the name specified in
+the statement refer to the binding of that name in the top-level namespace.
+Names are resolved in the top-level namespace by searching the global namespace,
+i.e. the namespace of the module containing the code block, and the builtin
+namespace, the namespace of the module :mod:`__builtin__`.  The global namespace
+is searched first.  If the name is not found there, the builtin namespace is
+searched.  The global statement must precede all uses of the name.
+
+.. index:: pair: restricted; execution
+
+The built-in namespace associated with the execution of a code block is actually
+found by looking up the name ``__builtins__`` in its global namespace; this
+should be a dictionary or a module (in the latter case the module's dictionary
+is used).  By default, when in the :mod:`__main__` module, ``__builtins__`` is
+the built-in module :mod:`__builtin__` (note: no 's'); when in any other module,
+``__builtins__`` is an alias for the dictionary of the :mod:`__builtin__` module
+itself.  ``__builtins__`` can be set to a user-created dictionary to create a
+weak form of restricted execution.
+
+.. note::
+
+   Users should not touch ``__builtins__``; it is strictly an implementation
+   detail.  Users wanting to override values in the built-in namespace should
+   :keyword:`import` the :mod:`__builtin__` (no 's') module and modify its
+   attributes appropriately.
+
+.. index:: module: __main__
+
+The namespace for a module is automatically created the first time a module is
+imported.  The main module for a script is always called :mod:`__main__`.
+
+The global statement has the same scope as a name binding operation in the same
+block.  If the nearest enclosing scope for a free variable contains a global
+statement, the free variable is treated as a global.
+
+A class definition is an executable statement that may use and define names.
+These references follow the normal rules for name resolution. The namespace of
+the class definition becomes the attribute dictionary of the class.  Names
+defined at the class scope are not visible in methods.
+
+
+.. _dynamic-features:
+
+Interaction with dynamic features
+---------------------------------
+
+There are several cases where Python statements are illegal when used in
+conjunction with nested scopes that contain free variables.
+
+If a variable is referenced in an enclosing scope, it is illegal to delete the
+name.  An error will be reported at compile time.
+
+If the wild card form of import --- ``import *`` --- is used in a function and
+the function contains or is a nested block with free variables, the compiler
+will raise a :exc:`SyntaxError`.
+
+The :func:`eval` and :func:`exec` functions do
+not have access to the full environment for resolving names.  Names may be
+resolved in the local and global namespaces of the caller.  Free variables are
+not resolved in the nearest enclosing namespace, but in the global namespace.
+[#]_ The :func:`exec` and :func:`eval` functions have optional
+arguments to override the global and local namespace.  If only one namespace is
+specified, it is used for both.
+
+
+.. _exceptions:
+
+Exceptions
+==========
+
+.. index:: single: exception
+
+.. index::
+   single: raise an exception
+   single: handle an exception
+   single: exception handler
+   single: errors
+   single: error handling
+
+Exceptions are a means of breaking out of the normal flow of control of a code
+block in order to handle errors or other exceptional conditions.  An exception
+is *raised* at the point where the error is detected; it may be *handled* by the
+surrounding code block or by any code block that directly or indirectly invoked
+the code block where the error occurred.
+
+The Python interpreter raises an exception when it detects a run-time error
+(such as division by zero).  A Python program can also explicitly raise an
+exception with the :keyword:`raise` statement. Exception handlers are specified
+with the :keyword:`try` ... :keyword:`except` statement.  The :keyword:`try` ...
+:keyword:`finally` statement specifies cleanup code which does not handle the
+exception, but is executed whether an exception occurred or not in the preceding
+code.
+
+.. index:: single: termination model
+
+Python uses the "termination" model of error handling: an exception handler can
+find out what happened and continue execution at an outer level, but it cannot
+repair the cause of the error and retry the failing operation (except by
+re-entering the offending piece of code from the top).
+
+.. index:: single: SystemExit (built-in exception)
+
+When an exception is not handled at all, the interpreter terminates execution of
+the program, or returns to its interactive main loop.  In either case, it prints
+a stack backtrace, except when the exception is  :exc:`SystemExit`.
+
+Exceptions are identified by class instances.  The :keyword:`except` clause is
+selected depending on the class of the instance: it must reference the class of
+the instance or a base class thereof.  The instance can be received by the
+handler and can carry additional information about the exceptional condition.
+
+Exceptions can also be identified by strings, in which case the
+:keyword:`except` clause is selected by object identity.  An arbitrary value can
+be raised along with the identifying string which can be passed to the handler.
+
+.. warning::
+
+   Messages to exceptions are not part of the Python API.  Their contents may
+   change from one version of Python to the next without warning and should not be
+   relied on by code which will run under multiple versions of the interpreter.
+
+See also the description of the :keyword:`try` statement in section :ref:`try`
+and :keyword:`raise` statement in section :ref:`raise`.
+
+.. rubric:: Footnotes
+
+.. [#] This limitation occurs because the code that is executed by these operations is
+   not available at the time the module is compiled.
+
diff --git a/Doc/reference/expressions.rst b/Doc/reference/expressions.rst
new file mode 100644
index 0000000..28c1406
--- /dev/null
+++ b/Doc/reference/expressions.rst
@@ -0,0 +1,1283 @@
+
+.. _expressions:
+
+***********
+Expressions
+***********
+
+.. index:: single: expression
+
+This chapter explains the meaning of the elements of expressions in Python.
+
+.. index:: single: BNF
+
+**Syntax Notes:** In this and the following chapters, extended BNF notation will
+be used to describe syntax, not lexical analysis.  When (one alternative of) a
+syntax rule has the form
+
+.. productionlist:: *
+   name: `othername`
+
+.. index:: single: syntax
+
+and no semantics are given, the semantics of this form of ``name`` are the same
+as for ``othername``.
+
+
+.. _conversions:
+
+Arithmetic conversions
+======================
+
+.. index:: pair: arithmetic; conversion
+
+.. XXX no coercion rules are documented anymore
+
+When a description of an arithmetic operator below uses the phrase "the numeric
+arguments are converted to a common type," the arguments are coerced using the
+coercion rules.  If both arguments are standard
+numeric types, the following coercions are applied:
+
+* If either argument is a complex number, the other is converted to complex;
+
+* otherwise, if either argument is a floating point number, the other is
+  converted to floating point;
+
+* otherwise, if either argument is a long integer, the other is converted to
+  long integer;
+
+* otherwise, both must be plain integers and no conversion is necessary.
+
+Some additional rules apply for certain operators (e.g., a string left argument
+to the '%' operator). Extensions can define their own coercions.
+
+
+.. _atoms:
+
+Atoms
+=====
+
+.. index:: single: atom
+
+Atoms are the most basic elements of expressions.  The simplest atoms are
+identifiers or literals.  Forms enclosed in reverse quotes or in parentheses,
+brackets or braces are also categorized syntactically as atoms.  The syntax for
+atoms is:
+
+.. productionlist::
+   atom: `identifier` | `literal` | `enclosure`
+   enclosure: `parenth_form` | `list_display`
+            : | `generator_expression` | `dict_display`
+            : | `string_conversion` | `yield_atom`
+
+
+.. _atom-identifiers:
+
+Identifiers (Names)
+-------------------
+
+.. index::
+   single: name
+   single: identifier
+
+An identifier occurring as an atom is a name.  See section :ref:`identifiers`
+for lexical definition and section :ref:`naming` for documentation of naming and
+binding.
+
+.. index:: exception: NameError
+
+When the name is bound to an object, evaluation of the atom yields that object.
+When a name is not bound, an attempt to evaluate it raises a :exc:`NameError`
+exception.
+
+.. index::
+   pair: name; mangling
+   pair: private; names
+
+**Private name mangling:** When an identifier that textually occurs in a class
+definition begins with two or more underscore characters and does not end in two
+or more underscores, it is considered a :dfn:`private name` of that class.
+Private names are transformed to a longer form before code is generated for
+them.  The transformation inserts the class name in front of the name, with
+leading underscores removed, and a single underscore inserted in front of the
+class name.  For example, the identifier ``__spam`` occurring in a class named
+``Ham`` will be transformed to ``_Ham__spam``.  This transformation is
+independent of the syntactical context in which the identifier is used.  If the
+transformed name is extremely long (longer than 255 characters), implementation
+defined truncation may happen.  If the class name consists only of underscores,
+no transformation is done.
+
+.. % 
+.. % 
+
+
+.. _atom-literals:
+
+Literals
+--------
+
+.. index:: single: literal
+
+Python supports string literals and various numeric literals:
+
+.. productionlist::
+   literal: `stringliteral` | `integer` | `longinteger`
+          : | `floatnumber` | `imagnumber`
+
+Evaluation of a literal yields an object of the given type (string, integer,
+long integer, floating point number, complex number) with the given value.  The
+value may be approximated in the case of floating point and imaginary (complex)
+literals.  See section :ref:`literals` for details.
+
+.. index::
+   triple: immutable; data; type
+   pair: immutable; object
+
+All literals correspond to immutable data types, and hence the object's identity
+is less important than its value.  Multiple evaluations of literals with the
+same value (either the same occurrence in the program text or a different
+occurrence) may obtain the same object or a different object with the same
+value.
+
+
+.. _parenthesized:
+
+Parenthesized forms
+-------------------
+
+.. index:: single: parenthesized form
+
+A parenthesized form is an optional expression list enclosed in parentheses:
+
+.. productionlist::
+   parenth_form: "(" [`expression_list`] ")"
+
+A parenthesized expression list yields whatever that expression list yields: if
+the list contains at least one comma, it yields a tuple; otherwise, it yields
+the single expression that makes up the expression list.
+
+.. index:: pair: empty; tuple
+
+An empty pair of parentheses yields an empty tuple object.  Since tuples are
+immutable, the rules for literals apply (i.e., two occurrences of the empty
+tuple may or may not yield the same object).
+
+.. index::
+   single: comma
+   pair: tuple; display
+
+Note that tuples are not formed by the parentheses, but rather by use of the
+comma operator.  The exception is the empty tuple, for which parentheses *are*
+required --- allowing unparenthesized "nothing" in expressions would cause
+ambiguities and allow common typos to pass uncaught.
+
+
+.. _lists:
+
+List displays
+-------------
+
+.. index::
+   pair: list; display
+   pair: list; comprehensions
+
+A list display is a possibly empty series of expressions enclosed in square
+brackets:
+
+.. productionlist::
+   list_display: "[" [`expression_list` | `list_comprehension`] "]"
+   list_comprehension: `expression` `list_for`
+   list_for: "for" `target_list` "in" `old_expression_list` [`list_iter`]
+   old_expression_list: `old_expression` [("," `old_expression`)+ [","]]
+   list_iter: `list_for` | `list_if`
+   list_if: "if" `old_expression` [`list_iter`]
+
+.. index::
+   pair: list; comprehensions
+   object: list
+   pair: empty; list
+
+A list display yields a new list object.  Its contents are specified by
+providing either a list of expressions or a list comprehension.  When a
+comma-separated list of expressions is supplied, its elements are evaluated from
+left to right and placed into the list object in that order.  When a list
+comprehension is supplied, it consists of a single expression followed by at
+least one :keyword:`for` clause and zero or more :keyword:`for` or :keyword:`if`
+clauses.  In this case, the elements of the new list are those that would be
+produced by considering each of the :keyword:`for` or :keyword:`if` clauses a
+block, nesting from left to right, and evaluating the expression to produce a
+list element each time the innermost block is reached [#]_.
+
+
+.. _genexpr:
+
+Generator expressions
+---------------------
+
+.. index:: pair: generator; expression
+
+A generator expression is a compact generator notation in parentheses:
+
+.. productionlist::
+   generator_expression: "(" `expression` `genexpr_for` ")"
+   genexpr_for: "for" `target_list` "in" `or_test` [`genexpr_iter`]
+   genexpr_iter: `genexpr_for` | `genexpr_if`
+   genexpr_if: "if" `old_expression` [`genexpr_iter`]
+
+.. index:: object: generator
+
+A generator expression yields a new generator object.  It consists of a single
+expression followed by at least one :keyword:`for` clause and zero or more
+:keyword:`for` or :keyword:`if` clauses.  The iterating values of the new
+generator are those that would be produced by considering each of the
+:keyword:`for` or :keyword:`if` clauses a block, nesting from left to right, and
+evaluating the expression to yield a value that is reached the innermost block
+for each iteration.
+
+Variables used in the generator expression are evaluated lazily when the
+:meth:`__next__` method is called for generator object (in the same fashion as
+normal generators). However, the leftmost :keyword:`for` clause is immediately
+evaluated so that error produced by it can be seen before any other possible
+error in the code that handles the generator expression. Subsequent
+:keyword:`for` clauses cannot be evaluated immediately since they may depend on
+the previous :keyword:`for` loop. For example: ``(x*y for x in range(10) for y
+in bar(x))``.
+
+The parentheses can be omitted on calls with only one argument. See section
+:ref:`calls` for the detail.
+
+
+.. _dict:
+
+Dictionary displays
+-------------------
+
+.. index:: pair: dictionary; display
+
+.. index::
+   single: key
+   single: datum
+   single: key/datum pair
+
+A dictionary display is a possibly empty series of key/datum pairs enclosed in
+curly braces:
+
+.. productionlist::
+   dict_display: "{" [`key_datum_list`] "}"
+   key_datum_list: `key_datum` ("," `key_datum`)* [","]
+   key_datum: `expression` ":" `expression`
+
+.. index:: object: dictionary
+
+A dictionary display yields a new dictionary object.
+
+The key/datum pairs are evaluated from left to right to define the entries of
+the dictionary: each key object is used as a key into the dictionary to store
+the corresponding datum.
+
+.. index:: pair: immutable; object
+
+Restrictions on the types of the key values are listed earlier in section
+:ref:`types`.  (To summarize, the key type should be hashable, which excludes
+all mutable objects.)  Clashes between duplicate keys are not detected; the last
+datum (textually rightmost in the display) stored for a given key value
+prevails.
+
+
+.. _yieldexpr:
+
+Yield expressions
+-----------------
+
+.. index::
+   keyword: yield
+   pair: yield; expression
+   pair: generator; function
+
+.. productionlist::
+   yield_atom: "(" `yield_expression` ")"
+   yield_expression: "yield" [`expression_list`]
+
+.. versionadded:: 2.5
+
+The :keyword:`yield` expression is only used when defining a generator function,
+and can only be used in the body of a function definition. Using a
+:keyword:`yield` expression in a function definition is sufficient to cause that
+definition to create a generator function instead of a normal function.
+
+When a generator function is called, it returns an iterator known as a
+generator.  That generator then controls the execution of a generator function.
+The execution starts when one of the generator's methods is called.  At that
+time, the execution proceeds to the first :keyword:`yield` expression, where it
+is suspended again, returning the value of :token:`expression_list` to
+generator's caller.  By suspended we mean that all local state is retained,
+including the current bindings of local variables, the instruction pointer, and
+the internal evaluation stack.  When the execution is resumed by calling one of
+the generator's methods, the function can proceed exactly as if the
+:keyword:`yield` expression was just another external call. The value of the
+:keyword:`yield` expression after resuming depends on the method which resumed
+the execution.
+
+.. index:: single: coroutine
+
+All of this makes generator functions quite similar to coroutines; they yield
+multiple times, they have more than one entry point and their execution can be
+suspended.  The only difference is that a generator function cannot control
+where should the execution continue after it yields; the control is always
+transfered to the generator's caller.
+
+.. index:: object: generator
+
+The following generator's methods can be used to control the execution of a
+generator function:
+
+.. index:: exception: StopIteration
+
+
+.. method:: generator.next()
+
+   Starts the execution of a generator function or resumes it at the last executed
+   :keyword:`yield` expression.  When a generator function is resumed with a
+   :meth:`next` method, the current :keyword:`yield` expression always evaluates to
+   :const:`None`.  The execution then continues to the next :keyword:`yield`
+   expression, where the generator is suspended again, and the value of the
+   :token:`expression_list` is returned to :meth:`next`'s caller. If the generator
+   exits without yielding another value, a :exc:`StopIteration` exception is
+   raised.
+
+
+.. method:: generator.send(value)
+
+   Resumes the execution and "sends" a value into the generator function.  The
+   ``value`` argument becomes the result of the current :keyword:`yield`
+   expression.  The :meth:`send` method returns the next value yielded by the
+   generator, or raises :exc:`StopIteration` if the generator exits without
+   yielding another value. When :meth:`send` is called to start the generator, it
+   must be called with :const:`None` as the argument, because there is no
+   :keyword:`yield` expression that could receieve the value.
+
+
+.. method:: generator.throw(type[, value[, traceback]])
+
+   Raises an exception of type ``type`` at the point where generator was paused,
+   and returns the next value yielded by the generator function.  If the generator
+   exits without yielding another value, a :exc:`StopIteration` exception is
+   raised.  If the generator function does not catch the passed-in exception, or
+   raises a different exception, then that exception propagates to the caller.
+
+.. index:: exception: GeneratorExit
+
+
+.. method:: generator.close()
+
+   Raises a :exc:`GeneratorExit` at the point where the generator function was
+   paused.  If the generator function then raises :exc:`StopIteration` (by exiting
+   normally, or due to already being closed) or :exc:`GeneratorExit` (by not
+   catching the exception), close returns to its caller.  If the generator yields a
+   value, a :exc:`RuntimeError` is raised.  If the generator raises any other
+   exception, it is propagated to the caller.  :meth:`close` does nothing if the
+   generator has already exited due to an exception or normal exit.
+
+Here is a simple example that demonstrates the behavior of generators and
+generator functions::
+
+   >>> def echo(value=None):
+   ...     print "Execution starts when 'next()' is called for the first time."
+   ...     try:
+   ...         while True:
+   ...             try:
+   ...                 value = (yield value)
+   ...             except GeneratorExit:
+   ...                 # never catch GeneratorExit
+   ...                 raise
+   ...             except Exception, e:
+   ...                 value = e
+   ...     finally:
+   ...         print "Don't forget to clean up when 'close()' is called."
+   ...
+   >>> generator = echo(1)
+   >>> print generator.next()
+   Execution starts when 'next()' is called for the first time.
+   1
+   >>> print generator.next()
+   None
+   >>> print generator.send(2)
+   2
+   >>> generator.throw(TypeError, "spam")
+   TypeError('spam',)
+   >>> generator.close()
+   Don't forget to clean up when 'close()' is called.
+
+
+.. seealso::
+
+   :pep:`0342` - Coroutines via Enhanced Generators
+      The proposal to enhance the API and syntax of generators, making them usable as
+      simple coroutines.
+
+
+.. _primaries:
+
+Primaries
+=========
+
+.. index:: single: primary
+
+Primaries represent the most tightly bound operations of the language. Their
+syntax is:
+
+.. productionlist::
+   primary: `atom` | `attributeref` | `subscription` | `slicing` | `call`
+
+
+.. _attribute-references:
+
+Attribute references
+--------------------
+
+.. index:: pair: attribute; reference
+
+An attribute reference is a primary followed by a period and a name:
+
+.. productionlist::
+   attributeref: `primary` "." `identifier`
+
+.. index::
+   exception: AttributeError
+   object: module
+   object: list
+
+The primary must evaluate to an object of a type that supports attribute
+references, e.g., a module, list, or an instance.  This object is then asked to
+produce the attribute whose name is the identifier.  If this attribute is not
+available, the exception :exc:`AttributeError` is raised. Otherwise, the type
+and value of the object produced is determined by the object.  Multiple
+evaluations of the same attribute reference may yield different objects.
+
+
+.. _subscriptions:
+
+Subscriptions
+-------------
+
+.. index:: single: subscription
+
+.. index::
+   object: sequence
+   object: mapping
+   object: string
+   object: tuple
+   object: list
+   object: dictionary
+   pair: sequence; item
+
+A subscription selects an item of a sequence (string, tuple or list) or mapping
+(dictionary) object:
+
+.. productionlist::
+   subscription: `primary` "[" `expression_list` "]"
+
+The primary must evaluate to an object of a sequence or mapping type.
+
+If the primary is a mapping, the expression list must evaluate to an object
+whose value is one of the keys of the mapping, and the subscription selects the
+value in the mapping that corresponds to that key.  (The expression list is a
+tuple except if it has exactly one item.)
+
+If the primary is a sequence, the expression (list) must evaluate to a plain
+integer.  If this value is negative, the length of the sequence is added to it
+(so that, e.g., ``x[-1]`` selects the last item of ``x``.)  The resulting value
+must be a nonnegative integer less than the number of items in the sequence, and
+the subscription selects the item whose index is that value (counting from
+zero).
+
+.. index::
+   single: character
+   pair: string; item
+
+A string's items are characters.  A character is not a separate data type but a
+string of exactly one character.
+
+
+.. _slicings:
+
+Slicings
+--------
+
+.. index::
+   single: slicing
+   single: slice
+
+.. index::
+   object: sequence
+   object: string
+   object: tuple
+   object: list
+
+A slicing selects a range of items in a sequence object (e.g., a string, tuple
+or list).  Slicings may be used as expressions or as targets in assignment or
+:keyword:`del` statements.  The syntax for a slicing:
+
+.. productionlist::
+   slicing: `simple_slicing` | `extended_slicing`
+   simple_slicing: `primary` "[" `short_slice` "]"
+   extended_slicing: `primary` "[" `slice_list` "]" 
+   slice_list: `slice_item` ("," `slice_item`)* [","]
+   slice_item: `expression` | `proper_slice` | `ellipsis`
+   proper_slice: `short_slice` | `long_slice`
+   short_slice: [`lower_bound`] ":" [`upper_bound`]
+   long_slice: `short_slice` ":" [`stride`]
+   lower_bound: `expression`
+   upper_bound: `expression`
+   stride: `expression`
+   ellipsis: "..."
+
+.. index:: pair: extended; slicing
+
+There is ambiguity in the formal syntax here: anything that looks like an
+expression list also looks like a slice list, so any subscription can be
+interpreted as a slicing.  Rather than further complicating the syntax, this is
+disambiguated by defining that in this case the interpretation as a subscription
+takes priority over the interpretation as a slicing (this is the case if the
+slice list contains no proper slice nor ellipses).  Similarly, when the slice
+list has exactly one short slice and no trailing comma, the interpretation as a
+simple slicing takes priority over that as an extended slicing.
+
+The semantics for a simple slicing are as follows.  The primary must evaluate to
+a sequence object.  The lower and upper bound expressions, if present, must
+evaluate to plain integers; defaults are zero and the ``sys.maxint``,
+respectively.  If either bound is negative, the sequence's length is added to
+it.  The slicing now selects all items with index *k* such that ``i <= k < j``
+where *i* and *j* are the specified lower and upper bounds.  This may be an
+empty sequence.  It is not an error if *i* or *j* lie outside the range of valid
+indexes (such items don't exist so they aren't selected).
+
+.. index::
+   single: start (slice object attribute)
+   single: stop (slice object attribute)
+   single: step (slice object attribute)
+
+The semantics for an extended slicing are as follows.  The primary must evaluate
+to a mapping object, and it is indexed with a key that is constructed from the
+slice list, as follows.  If the slice list contains at least one comma, the key
+is a tuple containing the conversion of the slice items; otherwise, the
+conversion of the lone slice item is the key.  The conversion of a slice item
+that is an expression is that expression.  The conversion of a proper slice is a
+slice object (see section :ref:`types`) whose :attr:`start`, :attr:`stop` and
+:attr:`step` attributes are the values of the expressions given as lower bound,
+upper bound and stride, respectively, substituting ``None`` for missing
+expressions.
+
+
+.. _calls:
+
+Calls
+-----
+
+.. index:: single: call
+
+.. index:: object: callable
+
+A call calls a callable object (e.g., a function) with a possibly empty series
+of arguments:
+
+.. productionlist::
+   call: `primary` "(" [`argument_list` [","]
+       : | `expression` `genexpr_for`] ")"
+   argument_list: `positional_arguments` ["," `keyword_arguments`]
+                : ["," "*" `expression`]
+                : ["," "**" `expression`]
+                : | `keyword_arguments` ["," "*" `expression`]
+                : ["," "**" `expression`]
+                : | "*" `expression` ["," "**" `expression`]
+                : | "**" `expression`
+   positional_arguments: `expression` ("," `expression`)*
+   keyword_arguments: `keyword_item` ("," `keyword_item`)*
+   keyword_item: `identifier` "=" `expression`
+
+A trailing comma may be present after the positional and keyword arguments but
+does not affect the semantics.
+
+The primary must evaluate to a callable object (user-defined functions, built-in
+functions, methods of built-in objects, class objects, methods of class
+instances, and certain class instances themselves are callable; extensions may
+define additional callable object types).  All argument expressions are
+evaluated before the call is attempted.  Please refer to section :ref:`function`
+for the syntax of formal parameter lists.
+
+If keyword arguments are present, they are first converted to positional
+arguments, as follows.  First, a list of unfilled slots is created for the
+formal parameters.  If there are N positional arguments, they are placed in the
+first N slots.  Next, for each keyword argument, the identifier is used to
+determine the corresponding slot (if the identifier is the same as the first
+formal parameter name, the first slot is used, and so on).  If the slot is
+already filled, a :exc:`TypeError` exception is raised. Otherwise, the value of
+the argument is placed in the slot, filling it (even if the expression is
+``None``, it fills the slot).  When all arguments have been processed, the slots
+that are still unfilled are filled with the corresponding default value from the
+function definition.  (Default values are calculated, once, when the function is
+defined; thus, a mutable object such as a list or dictionary used as default
+value will be shared by all calls that don't specify an argument value for the
+corresponding slot; this should usually be avoided.)  If there are any unfilled
+slots for which no default value is specified, a :exc:`TypeError` exception is
+raised.  Otherwise, the list of filled slots is used as the argument list for
+the call.
+
+If there are more positional arguments than there are formal parameter slots, a
+:exc:`TypeError` exception is raised, unless a formal parameter using the syntax
+``*identifier`` is present; in this case, that formal parameter receives a tuple
+containing the excess positional arguments (or an empty tuple if there were no
+excess positional arguments).
+
+If any keyword argument does not correspond to a formal parameter name, a
+:exc:`TypeError` exception is raised, unless a formal parameter using the syntax
+``**identifier`` is present; in this case, that formal parameter receives a
+dictionary containing the excess keyword arguments (using the keywords as keys
+and the argument values as corresponding values), or a (new) empty dictionary if
+there were no excess keyword arguments.
+
+If the syntax ``*expression`` appears in the function call, ``expression`` must
+evaluate to a sequence.  Elements from this sequence are treated as if they were
+additional positional arguments; if there are postional arguments *x1*,...,*xN*
+, and ``expression`` evaluates to a sequence *y1*,...,*yM*, this is equivalent
+to a call with M+N positional arguments *x1*,...,*xN*,*y1*,...,*yM*.
+
+A consequence of this is that although the ``*expression`` syntax appears
+*after* any keyword arguments, it is processed *before* the keyword arguments
+(and the ``**expression`` argument, if any -- see below).  So::
+
+   >>> def f(a, b):
+   ...  print a, b
+   ...
+   >>> f(b=1, *(2,))
+   2 1
+   >>> f(a=1, *(2,))
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   TypeError: f() got multiple values for keyword argument 'a'
+   >>> f(1, *(2,))
+   1 2
+
+It is unusual for both keyword arguments and the ``*expression`` syntax to be
+used in the same call, so in practice this confusion does not arise.
+
+If the syntax ``**expression`` appears in the function call, ``expression`` must
+evaluate to a mapping, the contents of which are treated as additional keyword
+arguments.  In the case of a keyword appearing in both ``expression`` and as an
+explicit keyword argument, a :exc:`TypeError` exception is raised.
+
+Formal parameters using the syntax ``*identifier`` or ``**identifier`` cannot be
+used as positional argument slots or as keyword argument names.
+
+A call always returns some value, possibly ``None``, unless it raises an
+exception.  How this value is computed depends on the type of the callable
+object.
+
+If it is---
+
+a user-defined function:
+   .. index::
+      pair: function; call
+      triple: user-defined; function; call
+      object: user-defined function
+      object: function
+
+   The code block for the function is executed, passing it the argument list.  The
+   first thing the code block will do is bind the formal parameters to the
+   arguments; this is described in section :ref:`function`.  When the code block
+   executes a :keyword:`return` statement, this specifies the return value of the
+   function call.
+
+a built-in function or method:
+   .. index::
+      pair: function; call
+      pair: built-in function; call
+      pair: method; call
+      pair: built-in method; call
+      object: built-in method
+      object: built-in function
+      object: method
+      object: function
+
+   The result is up to the interpreter; see :ref:`built-in-funcs` for the
+   descriptions of built-in functions and methods.
+
+a class object:
+   .. index::
+      object: class
+      pair: class object; call
+
+   A new instance of that class is returned.
+
+a class instance method:
+   .. index::
+      object: class instance
+      object: instance
+      pair: class instance; call
+
+   The corresponding user-defined function is called, with an argument list that is
+   one longer than the argument list of the call: the instance becomes the first
+   argument.
+
+a class instance:
+   .. index::
+      pair: instance; call
+      single: __call__() (object method)
+
+   The class must define a :meth:`__call__` method; the effect is then the same as
+   if that method was called.
+
+
+.. _power:
+
+The power operator
+==================
+
+The power operator binds more tightly than unary operators on its left; it binds
+less tightly than unary operators on its right.  The syntax is:
+
+.. productionlist::
+   power: `primary` ["**" `u_expr`]
+
+Thus, in an unparenthesized sequence of power and unary operators, the operators
+are evaluated from right to left (this does not constrain the evaluation order
+for the operands).
+
+The power operator has the same semantics as the built-in :func:`pow` function,
+when called with two arguments: it yields its left argument raised to the power
+of its right argument.  The numeric arguments are first converted to a common
+type.  The result type is that of the arguments after coercion.
+
+With mixed operand types, the coercion rules for binary arithmetic operators
+apply. For int and long int operands, the result has the same type as the
+operands (after coercion) unless the second argument is negative; in that case,
+all arguments are converted to float and a float result is delivered. For
+example, ``10**2`` returns ``100``, but ``10**-2`` returns ``0.01``. (This last
+feature was added in Python 2.2. In Python 2.1 and before, if both arguments
+were of integer types and the second argument was negative, an exception was
+raised).
+
+Raising ``0.0`` to a negative power results in a :exc:`ZeroDivisionError`.
+Raising a negative number to a fractional power results in a :exc:`ValueError`.
+
+
+.. _unary:
+
+Unary arithmetic operations
+===========================
+
+.. index::
+   triple: unary; arithmetic; operation
+   triple: unary; bit-wise; operation
+
+All unary arithmetic (and bit-wise) operations have the same priority:
+
+.. productionlist::
+   u_expr: `power` | "-" `u_expr` | "+" `u_expr` | "~" `u_expr`
+
+.. index::
+   single: negation
+   single: minus
+
+The unary ``-`` (minus) operator yields the negation of its numeric argument.
+
+.. index:: single: plus
+
+The unary ``+`` (plus) operator yields its numeric argument unchanged.
+
+.. index:: single: inversion
+
+The unary ``~`` (invert) operator yields the bit-wise inversion of its plain or
+long integer argument.  The bit-wise inversion of ``x`` is defined as
+``-(x+1)``.  It only applies to integral numbers.
+
+.. index:: exception: TypeError
+
+In all three cases, if the argument does not have the proper type, a
+:exc:`TypeError` exception is raised.
+
+
+.. _binary:
+
+Binary arithmetic operations
+============================
+
+.. index:: triple: binary; arithmetic; operation
+
+The binary arithmetic operations have the conventional priority levels.  Note
+that some of these operations also apply to certain non-numeric types.  Apart
+from the power operator, there are only two levels, one for multiplicative
+operators and one for additive operators:
+
+.. productionlist::
+   m_expr: `u_expr` | `m_expr` "*" `u_expr` | `m_expr` "//" `u_expr` | `m_expr` "/" `u_expr`
+         : | `m_expr` "%" `u_expr`
+   a_expr: `m_expr` | `a_expr` "+" `m_expr` | `a_expr` "-" `m_expr`
+
+.. index:: single: multiplication
+
+The ``*`` (multiplication) operator yields the product of its arguments.  The
+arguments must either both be numbers, or one argument must be an integer (plain
+or long) and the other must be a sequence. In the former case, the numbers are
+converted to a common type and then multiplied together.  In the latter case,
+sequence repetition is performed; a negative repetition factor yields an empty
+sequence.
+
+.. index::
+   exception: ZeroDivisionError
+   single: division
+
+The ``/`` (division) and ``//`` (floor division) operators yield the quotient of
+their arguments.  The numeric arguments are first converted to a common type.
+Plain or long integer division yields an integer of the same type; the result is
+that of mathematical division with the 'floor' function applied to the result.
+Division by zero raises the :exc:`ZeroDivisionError` exception.
+
+.. index:: single: modulo
+
+The ``%`` (modulo) operator yields the remainder from the division of the first
+argument by the second.  The numeric arguments are first converted to a common
+type.  A zero right argument raises the :exc:`ZeroDivisionError` exception.  The
+arguments may be floating point numbers, e.g., ``3.14%0.7`` equals ``0.34``
+(since ``3.14`` equals ``4*0.7 + 0.34``.)  The modulo operator always yields a
+result with the same sign as its second operand (or zero); the absolute value of
+the result is strictly smaller than the absolute value of the second operand
+[#]_.
+
+The integer division and modulo operators are connected by the following
+identity: ``x == (x/y)*y + (x%y)``.  Integer division and modulo are also
+connected with the built-in function :func:`divmod`: ``divmod(x, y) == (x/y,
+x%y)``.  These identities don't hold for floating point numbers; there similar
+identities hold approximately where ``x/y`` is replaced by ``floor(x/y)`` or
+``floor(x/y) - 1`` [#]_.
+
+In addition to performing the modulo operation on numbers, the ``%`` operator is
+also overloaded by string and unicode objects to perform string formatting (also
+known as interpolation). The syntax for string formatting is described in the
+Python Library Reference, section :ref:`string-formatting`.
+
+The floor division operator, the modulo operator, and the :func:`divmod`
+function are not defined for complex numbers.  Instead, convert to a
+floating point number using the :func:`abs` function if appropriate.
+
+.. index:: single: addition
+
+The ``+`` (addition) operator yields the sum of its arguments. The arguments
+must either both be numbers or both sequences of the same type.  In the former
+case, the numbers are converted to a common type and then added together.  In
+the latter case, the sequences are concatenated.
+
+.. index:: single: subtraction
+
+The ``-`` (subtraction) operator yields the difference of its arguments.  The
+numeric arguments are first converted to a common type.
+
+
+.. _shifting:
+
+Shifting operations
+===================
+
+.. index:: pair: shifting; operation
+
+The shifting operations have lower priority than the arithmetic operations:
+
+.. productionlist::
+   shift_expr: `a_expr` | `shift_expr` ( "<<" | ">>" ) `a_expr`
+
+These operators accept plain or long integers as arguments.  The arguments are
+converted to a common type.  They shift the first argument to the left or right
+by the number of bits given by the second argument.
+
+.. index:: exception: ValueError
+
+A right shift by *n* bits is defined as division by ``pow(2,n)``.  A left shift
+by *n* bits is defined as multiplication with ``pow(2,n)``; for plain integers
+there is no overflow check so in that case the operation drops bits and flips
+the sign if the result is not less than ``pow(2,31)`` in absolute value.
+Negative shift counts raise a :exc:`ValueError` exception.
+
+
+.. _bitwise:
+
+Binary bit-wise operations
+==========================
+
+.. index:: triple: binary; bit-wise; operation
+
+Each of the three bitwise operations has a different priority level:
+
+.. productionlist::
+   and_expr: `shift_expr` | `and_expr` "&" `shift_expr`
+   xor_expr: `and_expr` | `xor_expr` "^" `and_expr`
+   or_expr: `xor_expr` | `or_expr` "|" `xor_expr`
+
+.. index:: pair: bit-wise; and
+
+The ``&`` operator yields the bitwise AND of its arguments, which must be plain
+or long integers.  The arguments are converted to a common type.
+
+.. index::
+   pair: bit-wise; xor
+   pair: exclusive; or
+
+The ``^`` operator yields the bitwise XOR (exclusive OR) of its arguments, which
+must be plain or long integers.  The arguments are converted to a common type.
+
+.. index::
+   pair: bit-wise; or
+   pair: inclusive; or
+
+The ``|`` operator yields the bitwise (inclusive) OR of its arguments, which
+must be plain or long integers.  The arguments are converted to a common type.
+
+
+.. _comparisons:
+
+Comparisons
+===========
+
+.. index:: single: comparison
+
+.. index:: pair: C; language
+
+Unlike C, all comparison operations in Python have the same priority, which is
+lower than that of any arithmetic, shifting or bitwise operation.  Also unlike
+C, expressions like ``a < b < c`` have the interpretation that is conventional
+in mathematics:
+
+.. productionlist::
+   comparison: `or_expr` ( `comp_operator` `or_expr` )*
+   comp_operator: "<" | ">" | "==" | ">=" | "<=" | "!="
+                : | "is" ["not"] | ["not"] "in"
+
+Comparisons yield boolean values: ``True`` or ``False``.
+
+.. index:: pair: chaining; comparisons
+
+Comparisons can be chained arbitrarily, e.g., ``x < y <= z`` is equivalent to
+``x < y and y <= z``, except that ``y`` is evaluated only once (but in both
+cases ``z`` is not evaluated at all when ``x < y`` is found to be false).
+
+Formally, if *a*, *b*, *c*, ..., *y*, *z* are expressions and *opa*, *opb*, ...,
+*opy* are comparison operators, then *a opa b opb c* ...*y opy z* is equivalent
+to *a opa b* :keyword:`and` *b opb c* :keyword:`and` ... *y opy z*, except that
+each expression is evaluated at most once.
+
+Note that *a opa b opb c* doesn't imply any kind of comparison between *a* and
+*c*, so that, e.g., ``x < y > z`` is perfectly legal (though perhaps not
+pretty).
+
+The operators ``<``, ``>``, ``==``, ``>=``, ``<=``, and ``!=`` compare the
+values of two objects.  The objects need not have the same type. If both are
+numbers, they are converted to a common type.  Otherwise, objects of different
+types *always* compare unequal, and are ordered consistently but arbitrarily.
+You can control comparison behavior of objects of non-builtin types by defining
+a ``__cmp__`` method or rich comparison methods like ``__gt__``, described in
+section :ref:`specialnames`.
+
+(This unusual definition of comparison was used to simplify the definition of
+operations like sorting and the :keyword:`in` and :keyword:`not in` operators.
+In the future, the comparison rules for objects of different types are likely to
+change.)
+
+Comparison of objects of the same type depends on the type:
+
+* Numbers are compared arithmetically.
+
+* Strings are compared lexicographically using the numeric equivalents (the
+  result of the built-in function :func:`ord`) of their characters.  Unicode and
+  8-bit strings are fully interoperable in this behavior.
+
+* Tuples and lists are compared lexicographically using comparison of
+  corresponding elements.  This means that to compare equal, each element must
+  compare equal and the two sequences must be of the same type and have the same
+  length.
+
+  If not equal, the sequences are ordered the same as their first differing
+  elements.  For example, ``cmp([1,2,x], [1,2,y])`` returns the same as
+  ``cmp(x,y)``.  If the corresponding element does not exist, the shorter sequence
+  is ordered first (for example, ``[1,2] < [1,2,3]``).
+
+* Mappings (dictionaries) compare equal if and only if their sorted (key, value)
+  lists compare equal. [#]_ Outcomes other than equality are resolved
+  consistently, but are not otherwise defined. [#]_
+
+* Most other objects of builtin types compare unequal unless they are the same
+  object; the choice whether one object is considered smaller or larger than
+  another one is made arbitrarily but consistently within one execution of a
+  program.
+
+The operators :keyword:`in` and :keyword:`not in` test for set membership.  ``x
+in s`` evaluates to true if *x* is a member of the set *s*, and false otherwise.
+``x not in s`` returns the negation of ``x in s``. The set membership test has
+traditionally been bound to sequences; an object is a member of a set if the set
+is a sequence and contains an element equal to that object.  However, it is
+possible for an object to support membership tests without being a sequence.  In
+particular, dictionaries support membership testing as a nicer way of spelling
+``key in dict``; other mapping types may follow suit.
+
+For the list and tuple types, ``x in y`` is true if and only if there exists an
+index *i* such that ``x == y[i]`` is true.
+
+For the Unicode and string types, ``x in y`` is true if and only if *x* is a
+substring of *y*.  An equivalent test is ``y.find(x) != -1``.  Note, *x* and *y*
+need not be the same type; consequently, ``u'ab' in 'abc'`` will return
+``True``. Empty strings are always considered to be a substring of any other
+string, so ``"" in "abc"`` will return ``True``.
+
+.. versionchanged:: 2.3
+   Previously, *x* was required to be a string of length ``1``.
+
+For user-defined classes which define the :meth:`__contains__` method, ``x in
+y`` is true if and only if ``y.__contains__(x)`` is true.
+
+For user-defined classes which do not define :meth:`__contains__` and do define
+:meth:`__getitem__`, ``x in y`` is true if and only if there is a non-negative
+integer index *i* such that ``x == y[i]``, and all lower integer indices do not
+raise :exc:`IndexError` exception. (If any other exception is raised, it is as
+if :keyword:`in` raised that exception).
+
+.. index::
+   operator: in
+   operator: not in
+   pair: membership; test
+   object: sequence
+
+The operator :keyword:`not in` is defined to have the inverse true value of
+:keyword:`in`.
+
+.. index::
+   operator: is
+   operator: is not
+   pair: identity; test
+
+The operators :keyword:`is` and :keyword:`is not` test for object identity: ``x
+is y`` is true if and only if *x* and *y* are the same object.  ``x is not y``
+yields the inverse truth value.
+
+
+.. _booleans:
+
+Boolean operations
+==================
+
+.. index::
+   pair: Conditional; expression
+   pair: Boolean; operation
+
+Boolean operations have the lowest priority of all Python operations:
+
+.. productionlist::
+   expression: `conditional_expression` | `lambda_form`
+   old_expression: `or_test` | `old_lambda_form`
+   conditional_expression: `or_test` ["if" `or_test` "else" `expression`]
+   or_test: `and_test` | `or_test` "or" `and_test`
+   and_test: `not_test` | `and_test` "and" `not_test`
+   not_test: `comparison` | "not" `not_test`
+
+In the context of Boolean operations, and also when expressions are used by
+control flow statements, the following values are interpreted as false:
+``False``, ``None``, numeric zero of all types, and empty strings and containers
+(including strings, tuples, lists, dictionaries, sets and frozensets).  All
+other values are interpreted as true.
+
+.. index:: operator: not
+
+The operator :keyword:`not` yields ``True`` if its argument is false, ``False``
+otherwise.
+
+The expression ``x if C else y`` first evaluates *C* (*not* *x*); if *C* is
+true, *x* is evaluated and its value is returned; otherwise, *y* is evaluated
+and its value is returned.
+
+.. versionadded:: 2.5
+
+.. index:: operator: and
+
+The expression ``x and y`` first evaluates *x*; if *x* is false, its value is
+returned; otherwise, *y* is evaluated and the resulting value is returned.
+
+.. index:: operator: or
+
+The expression ``x or y`` first evaluates *x*; if *x* is true, its value is
+returned; otherwise, *y* is evaluated and the resulting value is returned.
+
+(Note that neither :keyword:`and` nor :keyword:`or` restrict the value and type
+they return to ``False`` and ``True``, but rather return the last evaluated
+argument. This is sometimes useful, e.g., if ``s`` is a string that should be
+replaced by a default value if it is empty, the expression ``s or 'foo'`` yields
+the desired value.  Because :keyword:`not` has to invent a value anyway, it does
+not bother to return a value of the same type as its argument, so e.g., ``not
+'foo'`` yields ``False``, not ``''``.)
+
+
+.. _lambdas:
+
+Lambdas
+=======
+
+.. index::
+   pair: lambda; expression
+   pair: lambda; form
+   pair: anonymous; function
+
+.. productionlist::
+   lambda_form: "lambda" [`parameter_list`]: `expression`
+   old_lambda_form: "lambda" [`parameter_list`]: `old_expression`
+
+Lambda forms (lambda expressions) have the same syntactic position as
+expressions.  They are a shorthand to create anonymous functions; the expression
+``lambda arguments: expression`` yields a function object.  The unnamed object
+behaves like a function object defined with ::
+
+   def name(arguments):
+       return expression
+
+See section :ref:`function` for the syntax of parameter lists.  Note that
+functions created with lambda forms cannot contain statements or annotations.
+
+.. _lambda:
+
+
+.. _exprlists:
+
+Expression lists
+================
+
+.. index:: pair: expression; list
+
+.. productionlist::
+   expression_list: `expression` ( "," `expression` )* [","]
+
+.. index:: object: tuple
+
+An expression list containing at least one comma yields a tuple.  The length of
+the tuple is the number of expressions in the list.  The expressions are
+evaluated from left to right.
+
+.. index:: pair: trailing; comma
+
+The trailing comma is required only to create a single tuple (a.k.a. a
+*singleton*); it is optional in all other cases.  A single expression without a
+trailing comma doesn't create a tuple, but rather yields the value of that
+expression. (To create an empty tuple, use an empty pair of parentheses:
+``()``.)
+
+
+.. _evalorder:
+
+Evaluation order
+================
+
+.. index:: pair: evaluation; order
+
+Python evaluates expressions from left to right. Notice that while evaluating an
+assignment, the right-hand side is evaluated before the left-hand side.
+
+In the following lines, expressions will be evaluated in the arithmetic order of
+their suffixes::
+
+   expr1, expr2, expr3, expr4
+   (expr1, expr2, expr3, expr4)
+   {expr1: expr2, expr3: expr4}
+   expr1 + expr2 * (expr3 - expr4)
+   func(expr1, expr2, *expr3, **expr4)
+   expr3, expr4 = expr1, expr2
+
+
+.. _operator-summary:
+
+Summary
+=======
+
+.. index:: pair: operator; precedence
+
+The following table summarizes the operator precedences in Python, from lowest
+precedence (least binding) to highest precedence (most binding). Operators in
+the same box have the same precedence.  Unless the syntax is explicitly given,
+operators are binary.  Operators in the same box group left to right (except for
+comparisons, including tests, which all have the same precedence and chain from
+left to right --- see section :ref:`comparisons` --- and exponentiation, which
+groups from right to left).
+
++----------------------------------------------+-------------------------------------+
+| Operator                                     | Description                         |
++==============================================+=====================================+
+| :keyword:`lambda`                            | Lambda expression                   |
++----------------------------------------------+-------------------------------------+
+| :keyword:`or`                                | Boolean OR                          |
++----------------------------------------------+-------------------------------------+
+| :keyword:`and`                               | Boolean AND                         |
++----------------------------------------------+-------------------------------------+
+| :keyword:`not` *x*                           | Boolean NOT                         |
++----------------------------------------------+-------------------------------------+
+| :keyword:`in`, :keyword:`not` :keyword:`in`  | Membership tests                    |
++----------------------------------------------+-------------------------------------+
+| :keyword:`is`, :keyword:`is not`             | Identity tests                      |
++----------------------------------------------+-------------------------------------+
+| ``<``, ``<=``, ``>``, ``>=``, ``!=``, ``==`` | Comparisons                         |
++----------------------------------------------+-------------------------------------+
+| ``|``                                        | Bitwise OR                          |
++----------------------------------------------+-------------------------------------+
+| ``^``                                        | Bitwise XOR                         |
++----------------------------------------------+-------------------------------------+
+| ``&``                                        | Bitwise AND                         |
++----------------------------------------------+-------------------------------------+
+| ``<<``, ``>>``                               | Shifts                              |
++----------------------------------------------+-------------------------------------+
+| ``+``, ``-``                                 | Addition and subtraction            |
++----------------------------------------------+-------------------------------------+
+| ``*``, ``/``, ``%``                          | Multiplication, division, remainder |
++----------------------------------------------+-------------------------------------+
+| ``+x``, ``-x``                               | Positive, negative                  |
++----------------------------------------------+-------------------------------------+
+| ``~x``                                       | Bitwise not                         |
++----------------------------------------------+-------------------------------------+
+| ``**``                                       | Exponentiation                      |
++----------------------------------------------+-------------------------------------+
+| ``x.attribute``                              | Attribute reference                 |
++----------------------------------------------+-------------------------------------+
+| ``x[index]``                                 | Subscription                        |
++----------------------------------------------+-------------------------------------+
+| ``x[index:index]``                           | Slicing                             |
++----------------------------------------------+-------------------------------------+
+| ``f(arguments...)``                          | Function call                       |
++----------------------------------------------+-------------------------------------+
+| ``(expressions...)``                         | Binding or tuple display            |
++----------------------------------------------+-------------------------------------+
+| ``[expressions...]``                         | List display                        |
++----------------------------------------------+-------------------------------------+
+| ``{key:datum...}``                           | Dictionary display                  |
++----------------------------------------------+-------------------------------------+
+
+.. rubric:: Footnotes
+
+.. [#] In Python 2.3, a list comprehension "leaks" the control variables of each
+   ``for`` it contains into the containing scope.  However, this behavior is
+   deprecated, and relying on it will not work once this bug is fixed in a future
+   release
+
+.. [#] While ``abs(x%y) < abs(y)`` is true mathematically, for floats it may not be
+   true numerically due to roundoff.  For example, and assuming a platform on which
+   a Python float is an IEEE 754 double-precision number, in order that ``-1e-100 %
+   1e100`` have the same sign as ``1e100``, the computed result is ``-1e-100 +
+   1e100``, which is numerically exactly equal to ``1e100``.  Function :func:`fmod`
+   in the :mod:`math` module returns a result whose sign matches the sign of the
+   first argument instead, and so returns ``-1e-100`` in this case. Which approach
+   is more appropriate depends on the application.
+
+.. [#] If x is very close to an exact integer multiple of y, it's possible for
+   ``floor(x/y)`` to be one larger than ``(x-x%y)/y`` due to rounding.  In such
+   cases, Python returns the latter result, in order to preserve that
+   ``divmod(x,y)[0] * y + x % y`` be very close to ``x``.
+
+.. [#] The implementation computes this efficiently, without constructing lists or
+   sorting.
+
+.. [#] Earlier versions of Python used lexicographic comparison of the sorted (key,
+   value) lists, but this was very expensive for the common case of comparing for
+   equality.  An even earlier version of Python compared dictionaries by identity
+   only, but this caused surprises because people expected to be able to test a
+   dictionary for emptiness by comparing it to ``{}``.
+
diff --git a/Doc/reference/index.rst b/Doc/reference/index.rst
new file mode 100644
index 0000000..18bf053
--- /dev/null
+++ b/Doc/reference/index.rst
@@ -0,0 +1,30 @@
+.. _reference-index:
+
+#################################
+  The Python language reference
+#################################
+
+:Release: |version|
+:Date: |today|
+
+This reference manual describes the syntax and "core semantics" of the
+language. It is terse, but attempts to be exact and complete. The semantics of
+non-essential built-in object types and of the built-in functions and modules
+are described in :ref:`library-index`. For an informal introduction to the
+language, see :ref:`tutorial-index`. For C or C++ programmers, two additional
+manuals exist: :ref:`extending-index` describes the high-level picture of how to
+write a Python extension module, and the :ref:`c-api-index` describes the
+interfaces available to C/C++ programmers in detail.
+
+.. toctree::
+   :maxdepth: 2
+
+   introduction.rst
+   lexical_analysis.rst
+   datamodel.rst
+   executionmodel.rst
+   expressions.rst
+   simple_stmts.rst
+   compound_stmts.rst
+   toplevel_components.rst
+
diff --git a/Doc/reference/introduction.rst b/Doc/reference/introduction.rst
new file mode 100644
index 0000000..0d53719
--- /dev/null
+++ b/Doc/reference/introduction.rst
@@ -0,0 +1,138 @@
+
+.. _introduction:
+
+************
+Introduction
+************
+
+This reference manual describes the Python programming language. It is not
+intended as a tutorial.
+
+While I am trying to be as precise as possible, I chose to use English rather
+than formal specifications for everything except syntax and lexical analysis.
+This should make the document more understandable to the average reader, but
+will leave room for ambiguities. Consequently, if you were coming from Mars and
+tried to re-implement Python from this document alone, you might have to guess
+things and in fact you would probably end up implementing quite a different
+language. On the other hand, if you are using Python and wonder what the precise
+rules about a particular area of the language are, you should definitely be able
+to find them here. If you would like to see a more formal definition of the
+language, maybe you could volunteer your time --- or invent a cloning machine
+:-).
+
+It is dangerous to add too many implementation details to a language reference
+document --- the implementation may change, and other implementations of the
+same language may work differently.  On the other hand, there is currently only
+one Python implementation in widespread use (although alternate implementations
+exist), and its particular quirks are sometimes worth being mentioned,
+especially where the implementation imposes additional limitations.  Therefore,
+you'll find short "implementation notes" sprinkled throughout the text.
+
+Every Python implementation comes with a number of built-in and standard
+modules.  These are documented in :ref:`library-index`.  A few built-in modules
+are mentioned when they interact in a significant way with the language
+definition.
+
+
+.. _implementations:
+
+Alternate Implementations
+=========================
+
+Though there is one Python implementation which is by far the most popular,
+there are some alternate implementations which are of particular interest to
+different audiences.
+
+Known implementations include:
+
+CPython
+   This is the original and most-maintained implementation of Python, written in C.
+   New language features generally appear here first.
+
+Jython
+   Python implemented in Java.  This implementation can be used as a scripting
+   language for Java applications, or can be used to create applications using the
+   Java class libraries.  It is also often used to create tests for Java libraries.
+   More information can be found at `the Jython website <http://www.jython.org/>`_.
+
+Python for .NET
+   This implementation actually uses the CPython implementation, but is a managed
+   .NET application and makes .NET libraries available.  This was created by Brian
+   Lloyd.  For more information, see the `Python for .NET home page
+   <http://www.zope.org/Members/Brian/PythonNet>`_.
+
+IronPython
+   An alternate Python for .NET.  Unlike Python.NET, this is a complete Python
+   implementation that generates IL, and compiles Python code directly to .NET
+   assemblies.  It was created by Jim Hugunin, the original creator of Jython.  For
+   more information, see `the IronPython website
+   <http://workspaces.gotdotnet.com/ironpython>`_.
+
+PyPy
+   An implementation of Python written in Python; even the bytecode interpreter is
+   written in Python.  This is executed using CPython as the underlying
+   interpreter.  One of the goals of the project is to encourage experimentation
+   with the language itself by making it easier to modify the interpreter (since it
+   is written in Python).  Additional information is available on `the PyPy
+   project's home page <http://codespeak.net/pypy/>`_.
+
+Each of these implementations varies in some way from the language as documented
+in this manual, or introduces specific information beyond what's covered in the
+standard Python documentation.  Please refer to the implementation-specific
+documentation to determine what else you need to know about the specific
+implementation you're using.
+
+
+.. _notation:
+
+Notation
+========
+
+.. index::
+   single: BNF
+   single: grammar
+   single: syntax
+   single: notation
+
+The descriptions of lexical analysis and syntax use a modified BNF grammar
+notation.  This uses the following style of definition:
+
+.. productionlist:: *
+   name: `lc_letter` (`lc_letter` | "_")*
+   lc_letter: "a"..."z"
+
+The first line says that a ``name`` is an ``lc_letter`` followed by a sequence
+of zero or more ``lc_letter``\ s and underscores.  An ``lc_letter`` in turn is
+any of the single characters ``'a'`` through ``'z'``.  (This rule is actually
+adhered to for the names defined in lexical and grammar rules in this document.)
+
+Each rule begins with a name (which is the name defined by the rule) and
+``::=``.  A vertical bar (``|``) is used to separate alternatives; it is the
+least binding operator in this notation.  A star (``*``) means zero or more
+repetitions of the preceding item; likewise, a plus (``+``) means one or more
+repetitions, and a phrase enclosed in square brackets (``[ ]``) means zero or
+one occurrences (in other words, the enclosed phrase is optional).  The ``*``
+and ``+`` operators bind as tightly as possible; parentheses are used for
+grouping.  Literal strings are enclosed in quotes.  White space is only
+meaningful to separate tokens. Rules are normally contained on a single line;
+rules with many alternatives may be formatted alternatively with each line after
+the first beginning with a vertical bar.
+
+.. index::
+   single: lexical definitions
+   single: ASCII@ASCII
+
+In lexical definitions (as the example above), two more conventions are used:
+Two literal characters separated by three dots mean a choice of any single
+character in the given (inclusive) range of ASCII characters.  A phrase between
+angular brackets (``<...>``) gives an informal description of the symbol
+defined; e.g., this could be used to describe the notion of 'control character'
+if needed.
+
+Even though the notation used is almost the same, there is a big difference
+between the meaning of lexical and syntactic definitions: a lexical definition
+operates on the individual characters of the input source, while a syntax
+definition operates on the stream of tokens generated by the lexical analysis.
+All uses of BNF in the next chapter ("Lexical Analysis") are lexical
+definitions; uses in subsequent chapters are syntactic definitions.
+
diff --git a/Doc/reference/lexical_analysis.rst b/Doc/reference/lexical_analysis.rst
new file mode 100644
index 0000000..35e92cf
--- /dev/null
+++ b/Doc/reference/lexical_analysis.rst
@@ -0,0 +1,758 @@
+
+.. _lexical:
+
+****************
+Lexical analysis
+****************
+
+.. index::
+   single: lexical analysis
+   single: parser
+   single: token
+
+A Python program is read by a *parser*.  Input to the parser is a stream of
+*tokens*, generated by the *lexical analyzer*.  This chapter describes how the
+lexical analyzer breaks a file into tokens.
+
+Python uses the 7-bit ASCII character set for program text.
+
+.. versionadded:: 2.3
+   An encoding declaration can be used to indicate that  string literals and
+   comments use an encoding different from ASCII.
+
+For compatibility with older versions, Python only warns if it finds 8-bit
+characters; those warnings should be corrected by either declaring an explicit
+encoding, or using escape sequences if those bytes are binary data, instead of
+characters.
+
+The run-time character set depends on the I/O devices connected to the program
+but is generally a superset of ASCII.
+
+**Future compatibility note:** It may be tempting to assume that the character
+set for 8-bit characters is ISO Latin-1 (an ASCII superset that covers most
+western languages that use the Latin alphabet), but it is possible that in the
+future Unicode text editors will become common.  These generally use the UTF-8
+encoding, which is also an ASCII superset, but with very different use for the
+characters with ordinals 128-255.  While there is no consensus on this subject
+yet, it is unwise to assume either Latin-1 or UTF-8, even though the current
+implementation appears to favor Latin-1.  This applies both to the source
+character set and the run-time character set.
+
+
+.. _line-structure:
+
+Line structure
+==============
+
+.. index:: single: line structure
+
+A Python program is divided into a number of *logical lines*.
+
+
+.. _logical:
+
+Logical lines
+-------------
+
+.. index::
+   single: logical line
+   single: physical line
+   single: line joining
+   single: NEWLINE token
+
+The end of a logical line is represented by the token NEWLINE.  Statements
+cannot cross logical line boundaries except where NEWLINE is allowed by the
+syntax (e.g., between statements in compound statements). A logical line is
+constructed from one or more *physical lines* by following the explicit or
+implicit *line joining* rules.
+
+
+.. _physical:
+
+Physical lines
+--------------
+
+A physical line is a sequence of characters terminated by an end-of-line
+sequence.  In source files, any of the standard platform line termination
+sequences can be used - the Unix form using ASCII LF (linefeed), the Windows
+form using the ASCII sequence CR LF (return followed by linefeed), or the
+Macintosh form using the ASCII CR (return) character.  All of these forms can be
+used equally, regardless of platform.
+
+When embedding Python, source code strings should be passed to Python APIs using
+the standard C conventions for newline characters (the ``\n`` character,
+representing ASCII LF, is the line terminator).
+
+
+.. _comments:
+
+Comments
+--------
+
+.. index::
+   single: comment
+   single: hash character
+
+A comment starts with a hash character (``#``) that is not part of a string
+literal, and ends at the end of the physical line.  A comment signifies the end
+of the logical line unless the implicit line joining rules are invoked. Comments
+are ignored by the syntax; they are not tokens.
+
+
+.. _encodings:
+
+Encoding declarations
+---------------------
+
+.. index::
+   single: source character set
+   single: encodings
+
+If a comment in the first or second line of the Python script matches the
+regular expression ``coding[=:]\s*([-\w.]+)``, this comment is processed as an
+encoding declaration; the first group of this expression names the encoding of
+the source code file. The recommended forms of this expression are ::
+
+   # -*- coding: <encoding-name> -*-
+
+which is recognized also by GNU Emacs, and ::
+
+   # vim:fileencoding=<encoding-name>
+
+which is recognized by Bram Moolenaar's VIM. In addition, if the first bytes of
+the file are the UTF-8 byte-order mark (``'\xef\xbb\xbf'``), the declared file
+encoding is UTF-8 (this is supported, among others, by Microsoft's
+:program:`notepad`).
+
+If an encoding is declared, the encoding name must be recognized by Python. The
+encoding is used for all lexical analysis, in particular to find the end of a
+string, and to interpret the contents of Unicode literals. String literals are
+converted to Unicode for syntactical analysis, then converted back to their
+original encoding before interpretation starts. The encoding declaration must
+appear on a line of its own.
+
+.. % XXX there should be a list of supported encodings.
+
+
+.. _explicit-joining:
+
+Explicit line joining
+---------------------
+
+.. index::
+   single: physical line
+   single: line joining
+   single: line continuation
+   single: backslash character
+
+Two or more physical lines may be joined into logical lines using backslash
+characters (``\``), as follows: when a physical line ends in a backslash that is
+not part of a string literal or comment, it is joined with the following forming
+a single logical line, deleting the backslash and the following end-of-line
+character.  For example:
+
+.. % 
+
+::
+
+   if 1900 < year < 2100 and 1 <= month <= 12 \
+      and 1 <= day <= 31 and 0 <= hour < 24 \
+      and 0 <= minute < 60 and 0 <= second < 60:   # Looks like a valid date
+           return 1
+
+A line ending in a backslash cannot carry a comment.  A backslash does not
+continue a comment.  A backslash does not continue a token except for string
+literals (i.e., tokens other than string literals cannot be split across
+physical lines using a backslash).  A backslash is illegal elsewhere on a line
+outside a string literal.
+
+
+.. _implicit-joining:
+
+Implicit line joining
+---------------------
+
+Expressions in parentheses, square brackets or curly braces can be split over
+more than one physical line without using backslashes. For example::
+
+   month_names = ['Januari', 'Februari', 'Maart',      # These are the
+                  'April',   'Mei',      'Juni',       # Dutch names
+                  'Juli',    'Augustus', 'September',  # for the months
+                  'Oktober', 'November', 'December']   # of the year
+
+Implicitly continued lines can carry comments.  The indentation of the
+continuation lines is not important.  Blank continuation lines are allowed.
+There is no NEWLINE token between implicit continuation lines.  Implicitly
+continued lines can also occur within triple-quoted strings (see below); in that
+case they cannot carry comments.
+
+
+.. _blank-lines:
+
+Blank lines
+-----------
+
+.. index:: single: blank line
+
+A logical line that contains only spaces, tabs, formfeeds and possibly a
+comment, is ignored (i.e., no NEWLINE token is generated).  During interactive
+input of statements, handling of a blank line may differ depending on the
+implementation of the read-eval-print loop.  In the standard implementation, an
+entirely blank logical line (i.e. one containing not even whitespace or a
+comment) terminates a multi-line statement.
+
+
+.. _indentation:
+
+Indentation
+-----------
+
+.. index::
+   single: indentation
+   single: whitespace
+   single: leading whitespace
+   single: space
+   single: tab
+   single: grouping
+   single: statement grouping
+
+Leading whitespace (spaces and tabs) at the beginning of a logical line is used
+to compute the indentation level of the line, which in turn is used to determine
+the grouping of statements.
+
+First, tabs are replaced (from left to right) by one to eight spaces such that
+the total number of characters up to and including the replacement is a multiple
+of eight (this is intended to be the same rule as used by Unix).  The total
+number of spaces preceding the first non-blank character then determines the
+line's indentation.  Indentation cannot be split over multiple physical lines
+using backslashes; the whitespace up to the first backslash determines the
+indentation.
+
+**Cross-platform compatibility note:** because of the nature of text editors on
+non-UNIX platforms, it is unwise to use a mixture of spaces and tabs for the
+indentation in a single source file.  It should also be noted that different
+platforms may explicitly limit the maximum indentation level.
+
+A formfeed character may be present at the start of the line; it will be ignored
+for the indentation calculations above.  Formfeed characters occurring elsewhere
+in the leading whitespace have an undefined effect (for instance, they may reset
+the space count to zero).
+
+.. index::
+   single: INDENT token
+   single: DEDENT token
+
+The indentation levels of consecutive lines are used to generate INDENT and
+DEDENT tokens, using a stack, as follows.
+
+Before the first line of the file is read, a single zero is pushed on the stack;
+this will never be popped off again.  The numbers pushed on the stack will
+always be strictly increasing from bottom to top.  At the beginning of each
+logical line, the line's indentation level is compared to the top of the stack.
+If it is equal, nothing happens. If it is larger, it is pushed on the stack, and
+one INDENT token is generated.  If it is smaller, it *must* be one of the
+numbers occurring on the stack; all numbers on the stack that are larger are
+popped off, and for each number popped off a DEDENT token is generated.  At the
+end of the file, a DEDENT token is generated for each number remaining on the
+stack that is larger than zero.
+
+Here is an example of a correctly (though confusingly) indented piece of Python
+code::
+
+   def perm(l):
+           # Compute the list of all permutations of l
+       if len(l) <= 1:
+                     return [l]
+       r = []
+       for i in range(len(l)):
+                s = l[:i] + l[i+1:]
+                p = perm(s)
+                for x in p:
+                 r.append(l[i:i+1] + x)
+       return r
+
+The following example shows various indentation errors::
+
+    def perm(l):                       # error: first line indented
+   for i in range(len(l)):             # error: not indented
+       s = l[:i] + l[i+1:]
+           p = perm(l[:i] + l[i+1:])   # error: unexpected indent
+           for x in p:
+                   r.append(l[i:i+1] + x)
+               return r                # error: inconsistent dedent
+
+(Actually, the first three errors are detected by the parser; only the last
+error is found by the lexical analyzer --- the indentation of ``return r`` does
+not match a level popped off the stack.)
+
+
+.. _whitespace:
+
+Whitespace between tokens
+-------------------------
+
+Except at the beginning of a logical line or in string literals, the whitespace
+characters space, tab and formfeed can be used interchangeably to separate
+tokens.  Whitespace is needed between two tokens only if their concatenation
+could otherwise be interpreted as a different token (e.g., ab is one token, but
+a b is two tokens).
+
+
+.. _other-tokens:
+
+Other tokens
+============
+
+Besides NEWLINE, INDENT and DEDENT, the following categories of tokens exist:
+*identifiers*, *keywords*, *literals*, *operators*, and *delimiters*. Whitespace
+characters (other than line terminators, discussed earlier) are not tokens, but
+serve to delimit tokens. Where ambiguity exists, a token comprises the longest
+possible string that forms a legal token, when read from left to right.
+
+
+.. _identifiers:
+
+Identifiers and keywords
+========================
+
+.. index::
+   single: identifier
+   single: name
+
+Identifiers (also referred to as *names*) are described by the following lexical
+definitions:
+
+.. productionlist::
+   identifier: (`letter`|"_") (`letter` | `digit` | "_")*
+   letter: `lowercase` | `uppercase`
+   lowercase: "a"..."z"
+   uppercase: "A"..."Z"
+   digit: "0"..."9"
+
+Identifiers are unlimited in length.  Case is significant.
+
+
+.. _keywords:
+
+Keywords
+--------
+
+.. index::
+   single: keyword
+   single: reserved word
+
+The following identifiers are used as reserved words, or *keywords* of the
+language, and cannot be used as ordinary identifiers.  They must be spelled
+exactly as written here::
+
+   and       def       for       is        raise
+   as        del       from      lambda    return
+   assert    elif      global    not       try
+   break     else      if        or        while
+   class     except    import    pass      with
+   continue  finally   in        print     yield
+
+.. versionchanged:: 2.4
+   :const:`None` became a constant and is now recognized by the compiler as a name
+   for the built-in object :const:`None`.  Although it is not a keyword, you cannot
+   assign a different object to it.
+
+.. versionchanged:: 2.5
+   Both :keyword:`as` and :keyword:`with` are only recognized when the
+   ``with_statement`` future feature has been enabled. It will always be enabled in
+   Python 2.6.  See section :ref:`with` for details.  Note that using :keyword:`as`
+   and :keyword:`with` as identifiers will always issue a warning, even when the
+   ``with_statement`` future directive is not in effect.
+
+
+.. _id-classes:
+
+Reserved classes of identifiers
+-------------------------------
+
+Certain classes of identifiers (besides keywords) have special meanings.  These
+classes are identified by the patterns of leading and trailing underscore
+characters:
+
+``_*``
+   Not imported by ``from module import *``.  The special identifier ``_`` is used
+   in the interactive interpreter to store the result of the last evaluation; it is
+   stored in the :mod:`__builtin__` module.  When not in interactive mode, ``_``
+   has no special meaning and is not defined. See section :ref:`import`.
+
+   .. note::
+
+      The name ``_`` is often used in conjunction with internationalization;
+      refer to the documentation for the :mod:`gettext` module for more
+      information on this convention.
+
+``__*__``
+   System-defined names.  These names are defined by the interpreter and its
+   implementation (including the standard library); applications should not expect
+   to define additional names using this convention.  The set of names of this
+   class defined by Python may be extended in future versions. See section
+   :ref:`specialnames`.
+
+``__*``
+   Class-private names.  Names in this category, when used within the context of a
+   class definition, are re-written to use a mangled form to help avoid name
+   clashes between "private" attributes of base and derived classes. See section
+   :ref:`atom-identifiers`.
+
+
+.. _literals:
+
+Literals
+========
+
+.. index::
+   single: literal
+   single: constant
+
+Literals are notations for constant values of some built-in types.
+
+
+.. _strings:
+
+String literals
+---------------
+
+.. index:: single: string literal
+
+String literals are described by the following lexical definitions:
+
+.. index:: single: ASCII@ASCII
+
+.. productionlist::
+   stringliteral: [`stringprefix`](`shortstring` | `longstring`)
+   stringprefix: "r" | "u" | "ur" | "R" | "U" | "UR" | "Ur" | "uR"
+   shortstring: "'" `shortstringitem`* "'" | '"' `shortstringitem`* '"'
+   longstring: ""'" `longstringitem`* ""'"
+             : | '"""' `longstringitem`* '"""'
+   shortstringitem: `shortstringchar` | `escapeseq`
+   longstringitem: `longstringchar` | `escapeseq`
+   shortstringchar: <any source character except "\" or newline or the quote>
+   longstringchar: <any source character except "\">
+   escapeseq: "\" <any ASCII character>
+
+One syntactic restriction not indicated by these productions is that whitespace
+is not allowed between the :token:`stringprefix` and the rest of the string
+literal. The source character set is defined by the encoding declaration; it is
+ASCII if no encoding declaration is given in the source file; see section
+:ref:`encodings`.
+
+.. index::
+   single: triple-quoted string
+   single: Unicode Consortium
+   single: string; Unicode
+   single: raw string
+
+In plain English: String literals can be enclosed in matching single quotes
+(``'``) or double quotes (``"``).  They can also be enclosed in matching groups
+of three single or double quotes (these are generally referred to as
+*triple-quoted strings*).  The backslash (``\``) character is used to escape
+characters that otherwise have a special meaning, such as newline, backslash
+itself, or the quote character.  String literals may optionally be prefixed with
+a letter ``'r'`` or ``'R'``; such strings are called :dfn:`raw strings` and use
+different rules for interpreting backslash escape sequences.  A prefix of
+``'u'`` or ``'U'`` makes the string a Unicode string.  Unicode strings use the
+Unicode character set as defined by the Unicode Consortium and ISO 10646.  Some
+additional escape sequences, described below, are available in Unicode strings.
+The two prefix characters may be combined; in this case, ``'u'`` must appear
+before ``'r'``.
+
+In triple-quoted strings, unescaped newlines and quotes are allowed (and are
+retained), except that three unescaped quotes in a row terminate the string.  (A
+"quote" is the character used to open the string, i.e. either ``'`` or ``"``.)
+
+.. index::
+   single: physical line
+   single: escape sequence
+   single: Standard C
+   single: C
+
+Unless an ``'r'`` or ``'R'`` prefix is present, escape sequences in strings are
+interpreted according to rules similar to those used by Standard C.  The
+recognized escape sequences are:
+
++-----------------+---------------------------------+-------+
+| Escape Sequence | Meaning                         | Notes |
++=================+=================================+=======+
+| ``\newline``    | Ignored                         |       |
++-----------------+---------------------------------+-------+
+| ``\\``          | Backslash (``\``)               |       |
++-----------------+---------------------------------+-------+
+| ``\'``          | Single quote (``'``)            |       |
++-----------------+---------------------------------+-------+
+| ``\"``          | Double quote (``"``)            |       |
++-----------------+---------------------------------+-------+
+| ``\a``          | ASCII Bell (BEL)                |       |
++-----------------+---------------------------------+-------+
+| ``\b``          | ASCII Backspace (BS)            |       |
++-----------------+---------------------------------+-------+
+| ``\f``          | ASCII Formfeed (FF)             |       |
++-----------------+---------------------------------+-------+
+| ``\n``          | ASCII Linefeed (LF)             |       |
++-----------------+---------------------------------+-------+
+| ``\N{name}``    | Character named *name* in the   |       |
+|                 | Unicode database (Unicode only) |       |
++-----------------+---------------------------------+-------+
+| ``\r``          | ASCII Carriage Return (CR)      |       |
++-----------------+---------------------------------+-------+
+| ``\t``          | ASCII Horizontal Tab (TAB)      |       |
++-----------------+---------------------------------+-------+
+| ``\uxxxx``      | Character with 16-bit hex value | \(1)  |
+|                 | *xxxx* (Unicode only)           |       |
++-----------------+---------------------------------+-------+
+| ``\Uxxxxxxxx``  | Character with 32-bit hex value | \(2)  |
+|                 | *xxxxxxxx* (Unicode only)       |       |
++-----------------+---------------------------------+-------+
+| ``\v``          | ASCII Vertical Tab (VT)         |       |
++-----------------+---------------------------------+-------+
+| ``\ooo``        | Character with octal value      | (3,5) |
+|                 | *ooo*                           |       |
++-----------------+---------------------------------+-------+
+| ``\xhh``        | Character with hex value *hh*   | (4,5) |
++-----------------+---------------------------------+-------+
+
+.. index:: single: ASCII@ASCII
+
+Notes:
+
+(1)
+   Individual code units which form parts of a surrogate pair can be encoded using
+   this escape sequence.
+
+(2)
+   Any Unicode character can be encoded this way, but characters outside the Basic
+   Multilingual Plane (BMP) will be encoded using a surrogate pair if Python is
+   compiled to use 16-bit code units (the default).  Individual code units which
+   form parts of a surrogate pair can be encoded using this escape sequence.
+
+(3)
+   As in Standard C, up to three octal digits are accepted.
+
+(4)
+   Unlike in Standard C, at most two hex digits are accepted.
+
+(5)
+   In a string literal, hexadecimal and octal escapes denote the byte with the
+   given value; it is not necessary that the byte encodes a character in the source
+   character set. In a Unicode literal, these escapes denote a Unicode character
+   with the given value.
+
+.. index:: single: unrecognized escape sequence
+
+Unlike Standard C, all unrecognized escape sequences are left in the string
+unchanged, i.e., *the backslash is left in the string*.  (This behavior is
+useful when debugging: if an escape sequence is mistyped, the resulting output
+is more easily recognized as broken.)  It is also important to note that the
+escape sequences marked as "(Unicode only)" in the table above fall into the
+category of unrecognized escapes for non-Unicode string literals.
+
+When an ``'r'`` or ``'R'`` prefix is present, a character following a backslash
+is included in the string without change, and *all backslashes are left in the
+string*.  For example, the string literal ``r"\n"`` consists of two characters:
+a backslash and a lowercase ``'n'``.  String quotes can be escaped with a
+backslash, but the backslash remains in the string; for example, ``r"\""`` is a
+valid string literal consisting of two characters: a backslash and a double
+quote; ``r"\"`` is not a valid string literal (even a raw string cannot end in
+an odd number of backslashes).  Specifically, *a raw string cannot end in a
+single backslash* (since the backslash would escape the following quote
+character).  Note also that a single backslash followed by a newline is
+interpreted as those two characters as part of the string, *not* as a line
+continuation.
+
+When an ``'r'`` or ``'R'`` prefix is used in conjunction with a ``'u'`` or
+``'U'`` prefix, then the ``\uXXXX`` and ``\UXXXXXXXX`` escape sequences are
+processed while  *all other backslashes are left in the string*. For example,
+the string literal ``ur"\u0062\n"`` consists of three Unicode characters: 'LATIN
+SMALL LETTER B', 'REVERSE SOLIDUS', and 'LATIN SMALL LETTER N'. Backslashes can
+be escaped with a preceding backslash; however, both remain in the string.  As a
+result, ``\uXXXX`` escape sequences are only recognized when there are an odd
+number of backslashes.
+
+
+.. _string-catenation:
+
+String literal concatenation
+----------------------------
+
+Multiple adjacent string literals (delimited by whitespace), possibly using
+different quoting conventions, are allowed, and their meaning is the same as
+their concatenation.  Thus, ``"hello" 'world'`` is equivalent to
+``"helloworld"``.  This feature can be used to reduce the number of backslashes
+needed, to split long strings conveniently across long lines, or even to add
+comments to parts of strings, for example::
+
+   re.compile("[A-Za-z_]"       # letter or underscore
+              "[A-Za-z0-9_]*"   # letter, digit or underscore
+             )
+
+Note that this feature is defined at the syntactical level, but implemented at
+compile time.  The '+' operator must be used to concatenate string expressions
+at run time.  Also note that literal concatenation can use different quoting
+styles for each component (even mixing raw strings and triple quoted strings).
+
+
+.. _numbers:
+
+Numeric literals
+----------------
+
+.. index::
+   single: number
+   single: numeric literal
+   single: integer literal
+   single: plain integer literal
+   single: long integer literal
+   single: floating point literal
+   single: hexadecimal literal
+   single: octal literal
+   single: binary literal
+   single: decimal literal
+   single: imaginary literal
+   single: complex; literal
+
+There are four types of numeric literals: plain integers, long integers,
+floating point numbers, and imaginary numbers.  There are no complex literals
+(complex numbers can be formed by adding a real number and an imaginary number).
+
+Note that numeric literals do not include a sign; a phrase like ``-1`` is
+actually an expression composed of the unary operator '``-``' and the literal
+``1``.
+
+
+.. _integers:
+
+Integer literals
+----------------
+
+Integer literals are described by the following lexical definitions:
+
+.. productionlist::
+   integer: `decimalinteger` | `octinteger` | `hexinteger`
+   decimalinteger: `nonzerodigit` `digit`* | "0"+
+   octinteger: "0" ("o" | "O") `octdigit`+
+   hexinteger: "0" ("x" | "X") `hexdigit`+
+   bininteger: "0" ("b" | "B") `bindigit`+
+   nonzerodigit: "1"..."9"
+   octdigit: "0"..."7"
+   hexdigit: `digit` | "a"..."f" | "A"..."F"
+   bindigit: "0"..."1"
+
+Plain integer literals that are above the largest representable plain integer
+(e.g., 2147483647 when using 32-bit arithmetic) are accepted as if they were
+long integers instead. [#]_  There is no limit for long integer literals apart
+from what can be stored in available memory.
+
+Note that leading zeros in a non-zero decimal number are not allowed. This is
+for disambiguation with C-style octal literals, which Python used before version
+3.0.
+
+Some examples of integer literals::
+
+   7     2147483647                        0o177    0b100110111
+   3     79228162514264337593543950336     0o377    0x100000000
+         79228162514264337593543950336              0xdeadbeef						    
+
+
+.. _floating:
+
+Floating point literals
+-----------------------
+
+Floating point literals are described by the following lexical definitions:
+
+.. productionlist::
+   floatnumber: `pointfloat` | `exponentfloat`
+   pointfloat: [`intpart`] `fraction` | `intpart` "."
+   exponentfloat: (`intpart` | `pointfloat`) `exponent`
+   intpart: `digit`+
+   fraction: "." `digit`+
+   exponent: ("e" | "E") ["+" | "-"] `digit`+
+
+Note that the integer and exponent parts are always interpreted using radix 10.
+For example, ``077e010`` is legal, and denotes the same number as ``77e10``. The
+allowed range of floating point literals is implementation-dependent. Some
+examples of floating point literals::
+
+   3.14    10.    .001    1e100    3.14e-10    0e0
+
+Note that numeric literals do not include a sign; a phrase like ``-1`` is
+actually an expression composed of the unary operator ``-`` and the literal
+``1``.
+
+
+.. _imaginary:
+
+Imaginary literals
+------------------
+
+Imaginary literals are described by the following lexical definitions:
+
+.. productionlist::
+   imagnumber: (`floatnumber` | `intpart`) ("j" | "J")
+
+An imaginary literal yields a complex number with a real part of 0.0.  Complex
+numbers are represented as a pair of floating point numbers and have the same
+restrictions on their range.  To create a complex number with a nonzero real
+part, add a floating point number to it, e.g., ``(3+4j)``.  Some examples of
+imaginary literals::
+
+   3.14j   10.j    10j     .001j   1e100j  3.14e-10j 
+
+
+.. _operators:
+
+Operators
+=========
+
+.. index:: single: operators
+
+The following tokens are operators::
+
+   +       -       *       **      /       //      %
+   <<      >>      &       |       ^       ~
+   <       >       <=      >=      ==      !=
+
+
+.. _delimiters:
+
+Delimiters
+==========
+
+.. index:: single: delimiters
+
+The following tokens serve as delimiters in the grammar::
+
+   (       )       [       ]       {       }      @
+   ,       :       .       `       =       ;
+   +=      -=      *=      /=      //=     %=
+   &=      |=      ^=      >>=     <<=     **=
+
+The period can also occur in floating-point and imaginary literals.  A sequence
+of three periods has a special meaning as an ellipsis in slices. The second half
+of the list, the augmented assignment operators, serve lexically as delimiters,
+but also perform an operation.
+
+The following printing ASCII characters have special meaning as part of other
+tokens or are otherwise significant to the lexical analyzer::
+
+   '       "       #       \
+
+.. index:: single: ASCII@ASCII
+
+The following printing ASCII characters are not used in Python.  Their
+occurrence outside string literals and comments is an unconditional error::
+
+   $       ?
+
+.. rubric:: Footnotes
+
+.. [#] In versions of Python prior to 2.4, octal and hexadecimal literals in the range
+   just above the largest representable plain integer but below the largest
+   unsigned 32-bit number (on a machine using 32-bit arithmetic), 4294967296, were
+   taken as the negative plain integer obtained by subtracting 4294967296 from
+   their unsigned value.
+
diff --git a/Doc/reference/simple_stmts.rst b/Doc/reference/simple_stmts.rst
new file mode 100644
index 0000000..fbc626f
--- /dev/null
+++ b/Doc/reference/simple_stmts.rst
@@ -0,0 +1,825 @@
+
+.. _simple:
+
+*****************
+Simple statements
+*****************
+
+.. index:: pair: simple; statement
+
+Simple statements are comprised within a single logical line. Several simple
+statements may occur on a single line separated by semicolons.  The syntax for
+simple statements is:
+
+.. productionlist::
+   simple_stmt: `expression_stmt`
+              : | `assert_stmt`
+              : | `assignment_stmt`
+              : | `augmented_assignment_stmt`
+              : | `pass_stmt`
+              : | `del_stmt`
+              : | `return_stmt`
+              : | `yield_stmt`
+              : | `raise_stmt`
+              : | `break_stmt`
+              : | `continue_stmt`
+              : | `import_stmt`
+              : | `global_stmt`
+
+
+.. _exprstmts:
+
+Expression statements
+=====================
+
+.. index:: pair: expression; statement
+
+Expression statements are used (mostly interactively) to compute and write a
+value, or (usually) to call a procedure (a function that returns no meaningful
+result; in Python, procedures return the value ``None``).  Other uses of
+expression statements are allowed and occasionally useful.  The syntax for an
+expression statement is:
+
+.. productionlist::
+   expression_stmt: `expression_list`
+
+.. index:: pair: expression; list
+
+An expression statement evaluates the expression list (which may be a single
+expression).
+
+.. index::
+   builtin: repr
+   object: None
+   pair: string; conversion
+   single: output
+   pair: standard; output
+   pair: writing; values
+   pair: procedure; call
+
+In interactive mode, if the value is not ``None``, it is converted to a string
+using the built-in :func:`repr` function and the resulting string is written to
+standard output (see :func:`print`) on a line by itself.  (Expression
+statements yielding ``None`` are not written, so that procedure calls do not
+cause any output.)
+
+
+.. _assert:
+
+Assert statements
+=================
+
+.. index::
+   statement: assert
+   pair: debugging; assertions
+
+Assert statements are a convenient way to insert debugging assertions into a
+program:
+
+.. productionlist::
+   assert_stmt: "assert" `expression` ["," `expression`]
+
+The simple form, ``assert expression``, is equivalent to ::
+
+   if __debug__:
+      if not expression: raise AssertionError
+
+The extended form, ``assert expression1, expression2``, is equivalent to ::
+
+   if __debug__:
+      if not expression1: raise AssertionError, expression2
+
+.. index::
+   single: __debug__
+   exception: AssertionError
+
+These equivalences assume that ``__debug__`` and :exc:`AssertionError` refer to
+the built-in variables with those names.  In the current implementation, the
+built-in variable ``__debug__`` is ``True`` under normal circumstances,
+``False`` when optimization is requested (command line option -O).  The current
+code generator emits no code for an assert statement when optimization is
+requested at compile time.  Note that it is unnecessary to include the source
+code for the expression that failed in the error message; it will be displayed
+as part of the stack trace.
+
+Assignments to ``__debug__`` are illegal.  The value for the built-in variable
+is determined when the interpreter starts.
+
+
+.. _assignment:
+
+Assignment statements
+=====================
+
+.. index::
+   pair: assignment; statement
+   pair: binding; name
+   pair: rebinding; name
+   object: mutable
+   pair: attribute; assignment
+
+Assignment statements are used to (re)bind names to values and to modify
+attributes or items of mutable objects:
+
+.. productionlist::
+   assignment_stmt: (`target_list` "=")+ (`expression_list` | `yield_expression`)
+   target_list: `target` ("," `target`)* [","]
+   target: `identifier`
+         : | "(" `target_list` ")"
+         : | "[" `target_list` "]"
+         : | `attributeref`
+         : | `subscription`
+         : | `slicing`
+
+(See section :ref:`primaries` for the syntax definitions for the last three
+symbols.)
+
+.. index:: pair: expression; list
+
+An assignment statement evaluates the expression list (remember that this can be
+a single expression or a comma-separated list, the latter yielding a tuple) and
+assigns the single resulting object to each of the target lists, from left to
+right.
+
+.. index::
+   single: target
+   pair: target; list
+
+Assignment is defined recursively depending on the form of the target (list).
+When a target is part of a mutable object (an attribute reference, subscription
+or slicing), the mutable object must ultimately perform the assignment and
+decide about its validity, and may raise an exception if the assignment is
+unacceptable.  The rules observed by various types and the exceptions raised are
+given with the definition of the object types (see section :ref:`types`).
+
+.. index:: triple: target; list; assignment
+
+Assignment of an object to a target list is recursively defined as follows.
+
+* If the target list is a single target: The object is assigned to that target.
+
+* If the target list is a comma-separated list of targets: The object must be a
+  sequence with the same number of items as there are targets in the target list,
+  and the items are assigned, from left to right, to the corresponding targets.
+  (This rule is relaxed as of Python 1.5; in earlier versions, the object had to
+  be a tuple.  Since strings are sequences, an assignment like ``a, b = "xy"`` is
+  now legal as long as the string has the right length.)
+
+Assignment of an object to a single target is recursively defined as follows.
+
+* If the target is an identifier (name):
+
+    .. index:: statement: global
+
+* If the name does not occur in a :keyword:`global` statement in the current
+    code block: the name is bound to the object in the current local namespace.
+
+* Otherwise: the name is bound to the object in the current global namespace.
+
+  .. index:: single: destructor
+
+  The name is rebound if it was already bound.  This may cause the reference count
+  for the object previously bound to the name to reach zero, causing the object to
+  be deallocated and its destructor (if it has one) to be called.
+
+  .. % nested
+
+* If the target is a target list enclosed in parentheses or in square brackets:
+  The object must be a sequence with the same number of items as there are targets
+  in the target list, and its items are assigned, from left to right, to the
+  corresponding targets.
+
+  .. index:: pair: attribute; assignment
+
+* If the target is an attribute reference: The primary expression in the
+  reference is evaluated.  It should yield an object with assignable attributes;
+  if this is not the case, :exc:`TypeError` is raised.  That object is then asked
+  to assign the assigned object to the given attribute; if it cannot perform the
+  assignment, it raises an exception (usually but not necessarily
+  :exc:`AttributeError`).
+
+  .. index::
+     pair: subscription; assignment
+     object: mutable
+
+* If the target is a subscription: The primary expression in the reference is
+  evaluated.  It should yield either a mutable sequence object (such as a list) or
+  a mapping object (such as a dictionary). Next, the subscript expression is
+  evaluated.
+
+  .. index::
+     object: sequence
+     object: list
+
+  If the primary is a mutable sequence object (such as a list), the subscript must
+  yield a plain integer.  If it is negative, the sequence's length is added to it.
+  The resulting value must be a nonnegative integer less than the sequence's
+  length, and the sequence is asked to assign the assigned object to its item with
+  that index.  If the index is out of range, :exc:`IndexError` is raised
+  (assignment to a subscripted sequence cannot add new items to a list).
+
+  .. index::
+     object: mapping
+     object: dictionary
+
+  If the primary is a mapping object (such as a dictionary), the subscript must
+  have a type compatible with the mapping's key type, and the mapping is then
+  asked to create a key/datum pair which maps the subscript to the assigned
+  object.  This can either replace an existing key/value pair with the same key
+  value, or insert a new key/value pair (if no key with the same value existed).
+
+  .. index:: pair: slicing; assignment
+
+* If the target is a slicing: The primary expression in the reference is
+  evaluated.  It should yield a mutable sequence object (such as a list).  The
+  assigned object should be a sequence object of the same type.  Next, the lower
+  and upper bound expressions are evaluated, insofar they are present; defaults
+  are zero and the sequence's length.  The bounds should evaluate to (small)
+  integers.  If either bound is negative, the sequence's length is added to it.
+  The resulting bounds are clipped to lie between zero and the sequence's length,
+  inclusive.  Finally, the sequence object is asked to replace the slice with the
+  items of the assigned sequence.  The length of the slice may be different from
+  the length of the assigned sequence, thus changing the length of the target
+  sequence, if the object allows it.
+
+(In the current implementation, the syntax for targets is taken to be the same
+as for expressions, and invalid syntax is rejected during the code generation
+phase, causing less detailed error messages.)
+
+WARNING: Although the definition of assignment implies that overlaps between the
+left-hand side and the right-hand side are 'safe' (for example ``a, b = b, a``
+swaps two variables), overlaps *within* the collection of assigned-to variables
+are not safe!  For instance, the following program prints ``[0, 2]``::
+
+   x = [0, 1]
+   i = 0
+   i, x[i] = 1, 2
+   print x
+
+
+.. _augassign:
+
+Augmented assignment statements
+-------------------------------
+
+.. index::
+   pair: augmented; assignment
+   single: statement; assignment, augmented
+
+Augmented assignment is the combination, in a single statement, of a binary
+operation and an assignment statement:
+
+.. productionlist::
+   augmented_assignment_stmt: `target` `augop` (`expression_list` | `yield_expression`)
+   augop: "+=" | "-=" | "*=" | "/=" | "%=" | "**="
+        : | ">>=" | "<<=" | "&=" | "^=" | "|="
+
+(See section :ref:`primaries` for the syntax definitions for the last three
+symbols.)
+
+An augmented assignment evaluates the target (which, unlike normal assignment
+statements, cannot be an unpacking) and the expression list, performs the binary
+operation specific to the type of assignment on the two operands, and assigns
+the result to the original target.  The target is only evaluated once.
+
+An augmented assignment expression like ``x += 1`` can be rewritten as ``x = x +
+1`` to achieve a similar, but not exactly equal effect. In the augmented
+version, ``x`` is only evaluated once. Also, when possible, the actual operation
+is performed *in-place*, meaning that rather than creating a new object and
+assigning that to the target, the old object is modified instead.
+
+With the exception of assigning to tuples and multiple targets in a single
+statement, the assignment done by augmented assignment statements is handled the
+same way as normal assignments. Similarly, with the exception of the possible
+*in-place* behavior, the binary operation performed by augmented assignment is
+the same as the normal binary operations.
+
+For targets which are attribute references, the initial value is retrieved with
+a :meth:`getattr` and the result is assigned with a :meth:`setattr`.  Notice
+that the two methods do not necessarily refer to the same variable.  When
+:meth:`getattr` refers to a class variable, :meth:`setattr` still writes to an
+instance variable. For example::
+
+   class A:
+       x = 3    # class variable
+   a = A()
+   a.x += 1     # writes a.x as 4 leaving A.x as 3
+
+
+.. _pass:
+
+The :keyword:`pass` statement
+=============================
+
+.. index:: statement: pass
+
+.. productionlist::
+   pass_stmt: "pass"
+
+.. index:: pair: null; operation
+
+:keyword:`pass` is a null operation --- when it is executed, nothing happens.
+It is useful as a placeholder when a statement is required syntactically, but no
+code needs to be executed, for example::
+
+   def f(arg): pass    # a function that does nothing (yet)
+
+   class C: pass       # a class with no methods (yet)
+
+
+.. _del:
+
+The :keyword:`del` statement
+============================
+
+.. index:: statement: del
+
+.. productionlist::
+   del_stmt: "del" `target_list`
+
+.. index::
+   pair: deletion; target
+   triple: deletion; target; list
+
+Deletion is recursively defined very similar to the way assignment is defined.
+Rather that spelling it out in full details, here are some hints.
+
+Deletion of a target list recursively deletes each target, from left to right.
+
+.. index::
+   statement: global
+   pair: unbinding; name
+
+Deletion of a name removes the binding of that name  from the local or global
+namespace, depending on whether the name occurs in a :keyword:`global` statement
+in the same code block.  If the name is unbound, a :exc:`NameError` exception
+will be raised.
+
+.. index:: pair: free; variable
+
+It is illegal to delete a name from the local namespace if it occurs as a free
+variable in a nested block.
+
+.. index:: pair: attribute; deletion
+
+Deletion of attribute references, subscriptions and slicings is passed to the
+primary object involved; deletion of a slicing is in general equivalent to
+assignment of an empty slice of the right type (but even this is determined by
+the sliced object).
+
+
+.. _return:
+
+The :keyword:`return` statement
+===============================
+
+.. index:: statement: return
+
+.. productionlist::
+   return_stmt: "return" [`expression_list`]
+
+.. index::
+   pair: function; definition
+   pair: class; definition
+
+:keyword:`return` may only occur syntactically nested in a function definition,
+not within a nested class definition.
+
+If an expression list is present, it is evaluated, else ``None`` is substituted.
+
+:keyword:`return` leaves the current function call with the expression list (or
+``None``) as return value.
+
+.. index:: keyword: finally
+
+When :keyword:`return` passes control out of a :keyword:`try` statement with a
+:keyword:`finally` clause, that :keyword:`finally` clause is executed before
+really leaving the function.
+
+In a generator function, the :keyword:`return` statement is not allowed to
+include an :token:`expression_list`.  In that context, a bare :keyword:`return`
+indicates that the generator is done and will cause :exc:`StopIteration` to be
+raised.
+
+
+.. _yield:
+
+The :keyword:`yield` statement
+==============================
+
+.. index:: statement: yield
+
+.. productionlist::
+   yield_stmt: `yield_expression`
+
+.. index::
+   single: generator; function
+   single: generator; iterator
+   single: function; generator
+   exception: StopIteration
+
+The :keyword:`yield` statement is only used when defining a generator function,
+and is only used in the body of the generator function. Using a :keyword:`yield`
+statement in a function definition is sufficient to cause that definition to
+create a generator function instead of a normal function.
+
+When a generator function is called, it returns an iterator known as a generator
+iterator, or more commonly, a generator.  The body of the generator function is
+executed by calling the generator's :meth:`__next__` method repeatedly until it
+raises an exception.
+
+When a :keyword:`yield` statement is executed, the state of the generator is
+frozen and the value of :token:`expression_list` is returned to
+:meth:`__next__`'s caller.  By "frozen" we mean that all local state is
+retained, including the current bindings of local variables, the instruction
+pointer, and the internal evaluation stack: enough information is saved so that
+the next time :meth:`__next__` is invoked, the function can proceed exactly as
+if the :keyword:`yield` statement were just another external call.
+
+As of Python version 2.5, the :keyword:`yield` statement is now allowed in the
+:keyword:`try` clause of a :keyword:`try` ...  :keyword:`finally` construct.  If
+the generator is not resumed before it is finalized (by reaching a zero
+reference count or by being garbage collected), the generator-iterator's
+:meth:`close` method will be called, allowing any pending :keyword:`finally`
+clauses to execute.
+
+.. note::
+
+   In Python 2.2, the :keyword:`yield` statement is only allowed when the
+   ``generators`` feature has been enabled.  It will always be enabled in Python
+   2.3.  This ``__future__`` import statement can be used to enable the feature::
+
+      from __future__ import generators
+
+
+.. seealso::
+
+   :pep:`0255` - Simple Generators
+      The proposal for adding generators and the :keyword:`yield` statement to Python.
+
+   :pep:`0342` - Coroutines via Enhanced Generators
+      The proposal that, among other generator enhancements, proposed allowing
+      :keyword:`yield` to appear inside a :keyword:`try` ... :keyword:`finally` block.
+
+
+.. _raise:
+
+The :keyword:`raise` statement
+==============================
+
+.. index:: statement: raise
+
+.. productionlist::
+   raise_stmt: "raise" [`expression` ["," `expression` ["," `expression`]]]
+
+.. index::
+   single: exception
+   pair: raising; exception
+
+If no expressions are present, :keyword:`raise` re-raises the last exception
+that was active in the current scope.  If no exception is active in the current
+scope, a :exc:`TypeError` exception is raised indicating that this is an error
+(if running under IDLE, a :exc:`Queue.Empty` exception is raised instead).
+
+Otherwise, :keyword:`raise` evaluates the expressions to get three objects,
+using ``None`` as the value of omitted expressions.  The first two objects are
+used to determine the *type* and *value* of the exception.
+
+If the first object is an instance, the type of the exception is the class of
+the instance, the instance itself is the value, and the second object must be
+``None``.
+
+If the first object is a class, it becomes the type of the exception. The second
+object is used to determine the exception value: If it is an instance of the
+class, the instance becomes the exception value. If the second object is a
+tuple, it is used as the argument list for the class constructor; if it is
+``None``, an empty argument list is used, and any other object is treated as a
+single argument to the constructor.  The instance so created by calling the
+constructor is used as the exception value.
+
+.. index:: object: traceback
+
+If a third object is present and not ``None``, it must be a traceback object
+(see section :ref:`types`), and it is substituted instead of the current
+location as the place where the exception occurred.  If the third object is
+present and not a traceback object or ``None``, a :exc:`TypeError` exception is
+raised.  The three-expression form of :keyword:`raise` is useful to re-raise an
+exception transparently in an except clause, but :keyword:`raise` with no
+expressions should be preferred if the exception to be re-raised was the most
+recently active exception in the current scope.
+
+Additional information on exceptions can be found in section :ref:`exceptions`,
+and information about handling exceptions is in section :ref:`try`.
+
+
+.. _break:
+
+The :keyword:`break` statement
+==============================
+
+.. index:: statement: break
+
+.. productionlist::
+   break_stmt: "break"
+
+.. index::
+   statement: for
+   statement: while
+   pair: loop; statement
+
+:keyword:`break` may only occur syntactically nested in a :keyword:`for` or
+:keyword:`while` loop, but not nested in a function or class definition within
+that loop.
+
+.. index:: keyword: else
+
+It terminates the nearest enclosing loop, skipping the optional :keyword:`else`
+clause if the loop has one.
+
+.. index:: pair: loop control; target
+
+If a :keyword:`for` loop is terminated by :keyword:`break`, the loop control
+target keeps its current value.
+
+.. index:: keyword: finally
+
+When :keyword:`break` passes control out of a :keyword:`try` statement with a
+:keyword:`finally` clause, that :keyword:`finally` clause is executed before
+really leaving the loop.
+
+
+.. _continue:
+
+The :keyword:`continue` statement
+=================================
+
+.. index:: statement: continue
+
+.. productionlist::
+   continue_stmt: "continue"
+
+.. index::
+   statement: for
+   statement: while
+   pair: loop; statement
+   keyword: finally
+
+:keyword:`continue` may only occur syntactically nested in a :keyword:`for` or
+:keyword:`while` loop, but not nested in a function or class definition or
+:keyword:`finally` statement within that loop. [#]_ It continues with the next
+cycle of the nearest enclosing loop.
+
+
+.. _import:
+
+The :keyword:`import` statement
+===============================
+
+.. index::
+   statement: import
+   single: module; importing
+   pair: name; binding
+   keyword: from
+
+.. productionlist::
+   import_stmt: "import" `module` ["as" `name`] ( "," `module` ["as" `name`] )*
+              : | "from" `relative_module` "import" `identifier` ["as" `name`]
+              : ( "," `identifier` ["as" `name`] )*
+              : | "from" `relative_module` "import" "(" `identifier` ["as" `name`]
+              : ( "," `identifier` ["as" `name`] )* [","] ")"
+              : | "from" `module` "import" "*"
+   module: (`identifier` ".")* `identifier`
+   relative_module: "."* `module` | "."+
+   name: `identifier`
+
+Import statements are executed in two steps: (1) find a module, and initialize
+it if necessary; (2) define a name or names in the local namespace (of the scope
+where the :keyword:`import` statement occurs). The first form (without
+:keyword:`from`) repeats these steps for each identifier in the list.  The form
+with :keyword:`from` performs step (1) once, and then performs step (2)
+repeatedly.
+
+In this context, to "initialize" a built-in or extension module means to call an
+initialization function that the module must provide for the purpose (in the
+reference implementation, the function's name is obtained by prepending string
+"init" to the module's name); to "initialize" a Python-coded module means to
+execute the module's body.
+
+.. index::
+   single: modules (in module sys)
+   single: sys.modules
+   pair: module; name
+   pair: built-in; module
+   pair: user-defined; module
+   module: sys
+   pair: filename; extension
+   triple: module; search; path
+
+The system maintains a table of modules that have been or are being initialized,
+indexed by module name.  This table is accessible as ``sys.modules``.  When a
+module name is found in this table, step (1) is finished.  If not, a search for
+a module definition is started.  When a module is found, it is loaded.  Details
+of the module searching and loading process are implementation and platform
+specific.  It generally involves searching for a "built-in" module with the
+given name and then searching a list of locations given as ``sys.path``.
+
+.. index::
+   pair: module; initialization
+   exception: ImportError
+   single: code block
+   exception: SyntaxError
+
+If a built-in module is found, its built-in initialization code is executed and
+step (1) is finished.  If no matching file is found, :exc:`ImportError` is
+raised. If a file is found, it is parsed, yielding an executable code block.  If
+a syntax error occurs, :exc:`SyntaxError` is raised.  Otherwise, an empty module
+of the given name is created and inserted in the module table, and then the code
+block is executed in the context of this module.  Exceptions during this
+execution terminate step (1).
+
+When step (1) finishes without raising an exception, step (2) can begin.
+
+The first form of :keyword:`import` statement binds the module name in the local
+namespace to the module object, and then goes on to import the next identifier,
+if any.  If the module name is followed by :keyword:`as`, the name following
+:keyword:`as` is used as the local name for the module.
+
+.. index::
+   pair: name; binding
+   exception: ImportError
+
+The :keyword:`from` form does not bind the module name: it goes through the list
+of identifiers, looks each one of them up in the module found in step (1), and
+binds the name in the local namespace to the object thus found.  As with the
+first form of :keyword:`import`, an alternate local name can be supplied by
+specifying ":keyword:`as` localname".  If a name is not found,
+:exc:`ImportError` is raised.  If the list of identifiers is replaced by a star
+(``'*'``), all public names defined in the module are bound in the local
+namespace of the :keyword:`import` statement..
+
+.. index:: single: __all__ (optional module attribute)
+
+The *public names* defined by a module are determined by checking the module's
+namespace for a variable named ``__all__``; if defined, it must be a sequence of
+strings which are names defined or imported by that module.  The names given in
+``__all__`` are all considered public and are required to exist.  If ``__all__``
+is not defined, the set of public names includes all names found in the module's
+namespace which do not begin with an underscore character (``'_'``).
+``__all__`` should contain the entire public API. It is intended to avoid
+accidentally exporting items that are not part of the API (such as library
+modules which were imported and used within the module).
+
+The :keyword:`from` form with ``*`` may only occur in a module scope.  If the
+wild card form of import --- ``import *`` --- is used in a function and the
+function contains or is a nested block with free variables, the compiler will
+raise a :exc:`SyntaxError`.
+
+.. index::
+   keyword: from
+   statement: from
+
+.. index::
+   triple: hierarchical; module; names
+   single: packages
+   single: __init__.py
+
+**Hierarchical module names:** when the module names contains one or more dots,
+the module search path is carried out differently.  The sequence of identifiers
+up to the last dot is used to find a "package"; the final identifier is then
+searched inside the package.  A package is generally a subdirectory of a
+directory on ``sys.path`` that has a file :file:`__init__.py`. [XXX Can't be
+bothered to spell this out right now; see the URL
+http://www.python.org/doc/essays/packages.html for more details, also about how
+the module search works from inside a package.]
+
+.. % 
+
+.. index:: builtin: __import__
+
+The built-in function :func:`__import__` is provided to support applications
+that determine which modules need to be loaded dynamically; refer to
+:ref:`built-in-funcs` for additional information.
+
+
+.. _future:
+
+Future statements
+-----------------
+
+.. index:: pair: future; statement
+
+A :dfn:`future statement` is a directive to the compiler that a particular
+module should be compiled using syntax or semantics that will be available in a
+specified future release of Python.  The future statement is intended to ease
+migration to future versions of Python that introduce incompatible changes to
+the language.  It allows use of the new features on a per-module basis before
+the release in which the feature becomes standard.
+
+.. productionlist:: *
+   future_statement: "from" "__future__" "import" feature ["as" name]
+                   : ("," feature ["as" name])*
+                   : | "from" "__future__" "import" "(" feature ["as" name]
+                   : ("," feature ["as" name])* [","] ")"
+   feature: identifier
+   name: identifier
+
+A future statement must appear near the top of the module.  The only lines that
+can appear before a future statement are:
+
+* the module docstring (if any),
+* comments,
+* blank lines, and
+* other future statements.
+
+The features recognized by Python 2.5 are ``absolute_import``, ``division``,
+``generators``, ``nested_scopes`` and ``with_statement``.  ``generators`` and
+``nested_scopes``  are redundant in Python version 2.3 and above because they
+are always enabled.
+
+A future statement is recognized and treated specially at compile time: Changes
+to the semantics of core constructs are often implemented by generating
+different code.  It may even be the case that a new feature introduces new
+incompatible syntax (such as a new reserved word), in which case the compiler
+may need to parse the module differently.  Such decisions cannot be pushed off
+until runtime.
+
+For any given release, the compiler knows which feature names have been defined,
+and raises a compile-time error if a future statement contains a feature not
+known to it.
+
+The direct runtime semantics are the same as for any import statement: there is
+a standard module :mod:`__future__`, described later, and it will be imported in
+the usual way at the time the future statement is executed.
+
+The interesting runtime semantics depend on the specific feature enabled by the
+future statement.
+
+Note that there is nothing special about the statement::
+
+   import __future__ [as name]
+
+That is not a future statement; it's an ordinary import statement with no
+special semantics or syntax restrictions.
+
+Code compiled by calls to the builtin functions :func:`exec` and :func:`compile`
+that occur in a module :mod:`M` containing a future
+statement will, by default, use the new  syntax or semantics associated with the
+future statement.  This can, starting with Python 2.2 be controlled by optional
+arguments to :func:`compile` --- see the documentation of that function
+for details.
+
+A future statement typed at an interactive interpreter prompt will take effect
+for the rest of the interpreter session.  If an interpreter is started with the
+:option:`-i` option, is passed a script name to execute, and the script includes
+a future statement, it will be in effect in the interactive session started
+after the script is executed.
+
+
+.. _global:
+
+The :keyword:`global` statement
+===============================
+
+.. index:: statement: global
+
+.. productionlist::
+   global_stmt: "global" `identifier` ("," `identifier`)*
+
+.. index:: triple: global; name; binding
+
+The :keyword:`global` statement is a declaration which holds for the entire
+current code block.  It means that the listed identifiers are to be interpreted
+as globals.  It would be impossible to assign to a global variable without
+:keyword:`global`, although free variables may refer to globals without being
+declared global.
+
+Names listed in a :keyword:`global` statement must not be used in the same code
+block textually preceding that :keyword:`global` statement.
+
+Names listed in a :keyword:`global` statement must not be defined as formal
+parameters or in a :keyword:`for` loop control target, :keyword:`class`
+definition, function definition, or :keyword:`import` statement.
+
+(The current implementation does not enforce the latter two restrictions, but
+programs should not abuse this freedom, as future implementations may enforce
+them or silently change the meaning of the program.)
+
+.. index::
+   builtin: exec
+   builtin: eval
+   builtin: compile
+
+**Programmer's note:** the :keyword:`global` is a directive to the parser.  It
+applies only to code parsed at the same time as the :keyword:`global` statement.
+In particular, a :keyword:`global` statement contained in a string or code
+object supplied to the builtin :func:`exec` function does not affect the code
+block *containing* the function call, and code contained in such a string is
+unaffected by :keyword:`global` statements in the code containing the function
+call.  The same applies to the :func:`eval` and :func:`compile` functions.
+
+.. rubric:: Footnotes
+
+.. [#] It may occur within an :keyword:`except` or :keyword:`else` clause.  The
+   restriction on occurring in the :keyword:`try` clause is implementor's laziness
+   and will eventually be lifted.
+
diff --git a/Doc/reference/toplevel_components.rst b/Doc/reference/toplevel_components.rst
new file mode 100644
index 0000000..2149311
--- /dev/null
+++ b/Doc/reference/toplevel_components.rst
@@ -0,0 +1,123 @@
+
+.. _top-level:
+
+********************
+Top-level components
+********************
+
+.. index:: single: interpreter
+
+The Python interpreter can get its input from a number of sources: from a script
+passed to it as standard input or as program argument, typed in interactively,
+from a module source file, etc.  This chapter gives the syntax used in these
+cases.
+
+
+.. _programs:
+
+Complete Python programs
+========================
+
+.. index:: single: program
+
+.. index::
+   module: sys
+   module: __main__
+   module: __builtin__
+
+While a language specification need not prescribe how the language interpreter
+is invoked, it is useful to have a notion of a complete Python program.  A
+complete Python program is executed in a minimally initialized environment: all
+built-in and standard modules are available, but none have been initialized,
+except for :mod:`sys` (various system services), :mod:`__builtin__` (built-in
+functions, exceptions and ``None``) and :mod:`__main__`.  The latter is used to
+provide the local and global namespace for execution of the complete program.
+
+The syntax for a complete Python program is that for file input, described in
+the next section.
+
+.. index::
+   single: interactive mode
+   module: __main__
+
+The interpreter may also be invoked in interactive mode; in this case, it does
+not read and execute a complete program but reads and executes one statement
+(possibly compound) at a time.  The initial environment is identical to that of
+a complete program; each statement is executed in the namespace of
+:mod:`__main__`.
+
+.. index::
+   single: UNIX
+   single: command line
+   single: standard input
+
+Under Unix, a complete program can be passed to the interpreter in three forms:
+with the :option:`-c` *string* command line option, as a file passed as the
+first command line argument, or as standard input. If the file or standard input
+is a tty device, the interpreter enters interactive mode; otherwise, it executes
+the file as a complete program.
+
+
+.. _file-input:
+
+File input
+==========
+
+All input read from non-interactive files has the same form:
+
+.. productionlist::
+   file_input: (NEWLINE | `statement`)*
+
+This syntax is used in the following situations:
+
+* when parsing a complete Python program (from a file or from a string);
+
+* when parsing a module;
+
+* when parsing a string passed to the :func:`exec` function;
+
+
+.. _interactive:
+
+Interactive input
+=================
+
+Input in interactive mode is parsed using the following grammar:
+
+.. productionlist::
+   interactive_input: [`stmt_list`] NEWLINE | `compound_stmt` NEWLINE
+
+Note that a (top-level) compound statement must be followed by a blank line in
+interactive mode; this is needed to help the parser detect the end of the input.
+
+
+.. _expression-input:
+
+Expression input
+================
+
+.. index:: single: input
+
+.. index:: builtin: eval
+
+There are two forms of expression input.  Both ignore leading whitespace. The
+string argument to :func:`eval` must have the following form:
+
+.. productionlist::
+   eval_input: `expression_list` NEWLINE*
+
+.. index:: builtin: input
+
+The input line read by :func:`input` must have the following form:
+
+.. productionlist::
+   input_input: `expression_list` NEWLINE
+
+.. index::
+   object: file
+   single: input; raw
+   single: readline() (file method)
+
+Note: to read 'raw' input line without interpretation, you can use the the
+:meth:`readline` method of file objects, including ``sys.stdin``.
+
diff --git a/Doc/tools/sphinx-build.py b/Doc/tools/sphinx-build.py
new file mode 100644
index 0000000..20516b6
--- /dev/null
+++ b/Doc/tools/sphinx-build.py
@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+"""
+    Sphinx - Python documentation toolchain
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    :copyright: 2007 by Georg Brandl.
+    :license: Python license.
+"""
+
+import sys
+
+if __name__ == '__main__':
+    from sphinx import main
+    sys.exit(main(sys.argv))
diff --git a/Doc/tools/sphinx-web.py b/Doc/tools/sphinx-web.py
new file mode 100644
index 0000000..5f7b50b
--- /dev/null
+++ b/Doc/tools/sphinx-web.py
@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+"""
+    Sphinx - Python documentation webserver
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+    :copyright: 2007 by Georg Brandl.
+    :license: Python license.
+"""
+
+import sys
+
+if __name__ == '__main__':
+    from sphinx.web import main
+    sys.exit(main(sys.argv))
diff --git a/Doc/tutorial/appetite.rst b/Doc/tutorial/appetite.rst
new file mode 100644
index 0000000..f1c80e9
--- /dev/null
+++ b/Doc/tutorial/appetite.rst
@@ -0,0 +1,89 @@
+.. _tut-intro:
+
+**********************
+Whetting Your Appetite
+**********************
+
+If you do much work on computers, eventually you find that there's some task
+you'd like to automate.  For example, you may wish to perform a
+search-and-replace over a large number of text files, or rename and rearrange a
+bunch of photo files in a complicated way. Perhaps you'd like to write a small
+custom database, or a specialized GUI application, or a simple game.
+
+If you're a professional software developer, you may have to work with several
+C/C++/Java libraries but find the usual write/compile/test/re-compile cycle is
+too slow.  Perhaps you're writing a test suite for such a library and find
+writing the testing code a tedious task.  Or maybe you've written a program that
+could use an extension language, and you don't want to design and implement a
+whole new language for your application.
+
+Python is just the language for you.
+
+You could write a Unix shell script or Windows batch files for some of these
+tasks, but shell scripts are best at moving around files and changing text data,
+not well-suited for GUI applications or games. You could write a C/C++/Java
+program, but it can take a lot of development time to get even a first-draft
+program.  Python is simpler to use, available on Windows, MacOS X, and Unix
+operating systems, and will help you get the job done more quickly.
+
+Python is simple to use, but it is a real programming language, offering much
+more structure and support for large programs than shell scripts or batch files
+can offer.  On the other hand, Python also offers much more error checking than
+C, and, being a *very-high-level language*, it has high-level data types built
+in, such as flexible arrays and dictionaries.  Because of its more general data
+types Python is applicable to a much larger problem domain than Awk or even
+Perl, yet many things are at least as easy in Python as in those languages.
+
+Python allows you to split your program into modules that can be reused in other
+Python programs.  It comes with a large collection of standard modules that you
+can use as the basis of your programs --- or as examples to start learning to
+program in Python.  Some of these modules provide things like file I/O, system
+calls, sockets, and even interfaces to graphical user interface toolkits like
+Tk.
+
+Python is an interpreted language, which can save you considerable time during
+program development because no compilation and linking is necessary.  The
+interpreter can be used interactively, which makes it easy to experiment with
+features of the language, to write throw-away programs, or to test functions
+during bottom-up program development. It is also a handy desk calculator.
+
+Python enables programs to be written compactly and readably.  Programs written
+in Python are typically much shorter than equivalent C,  C++, or Java programs,
+for several reasons:
+
+* the high-level data types allow you to express complex operations in a single
+  statement;
+
+* statement grouping is done by indentation instead of beginning and ending
+  brackets;
+
+* no variable or argument declarations are necessary.
+
+Python is *extensible*: if you know how to program in C it is easy to add a new
+built-in function or module to the interpreter, either to perform critical
+operations at maximum speed, or to link Python programs to libraries that may
+only be available in binary form (such as a vendor-specific graphics library).
+Once you are really hooked, you can link the Python interpreter into an
+application written in C and use it as an extension or command language for that
+application.
+
+By the way, the language is named after the BBC show "Monty Python's Flying
+Circus" and has nothing to do with nasty reptiles.  Making references to Monty
+Python skits in documentation is not only allowed, it is encouraged!
+
+Now that you are all excited about Python, you'll want to examine it in some
+more detail.  Since the best way to learn a language is to use it, the tutorial
+invites you to play with the Python interpreter as you read.
+
+.. % \section{Where From Here \label{where}}
+
+In the next chapter, the mechanics of using the interpreter are explained.  This
+is rather mundane information, but essential for trying out the examples shown
+later.
+
+The rest of the tutorial introduces various features of the Python language and
+system through examples, beginning with simple expressions, statements and data
+types, through functions and modules, and finally touching upon advanced
+concepts like exceptions and user-defined classes.
+
+
diff --git a/Doc/tutorial/classes.rst b/Doc/tutorial/classes.rst
new file mode 100644
index 0000000..b733e1e
--- /dev/null
+++ b/Doc/tutorial/classes.rst
@@ -0,0 +1,792 @@
+.. _tut-classes:
+
+*******
+Classes
+*******
+
+Python's class mechanism adds classes to the language with a minimum of new
+syntax and semantics.  It is a mixture of the class mechanisms found in C++ and
+Modula-3.  As is true for modules, classes in Python do not put an absolute
+barrier between definition and user, but rather rely on the politeness of the
+user not to "break into the definition."  The most important features of classes
+are retained with full power, however: the class inheritance mechanism allows
+multiple base classes, a derived class can override any methods of its base
+class or classes, and a method can call the method of a base class with the same
+name.  Objects can contain an arbitrary amount of private data.
+
+In C++ terminology, all class members (including the data members) are *public*,
+and all member functions are *virtual*.  There are no special constructors or
+destructors.  As in Modula-3, there are no shorthands for referencing the
+object's members from its methods: the method function is declared with an
+explicit first argument representing the object, which is provided implicitly by
+the call.  As in Smalltalk, classes themselves are objects, albeit in the wider
+sense of the word: in Python, all data types are objects.  This provides
+semantics for importing and renaming.  Unlike  C++ and Modula-3, built-in types
+can be used as base classes for extension by the user.  Also, like in C++ but
+unlike in Modula-3, most built-in operators with special syntax (arithmetic
+operators, subscripting etc.) can be redefined for class instances.
+
+
+.. _tut-terminology:
+
+A Word About Terminology
+========================
+
+Lacking universally accepted terminology to talk about classes, I will make
+occasional use of Smalltalk and C++ terms.  (I would use Modula-3 terms, since
+its object-oriented semantics are closer to those of Python than C++, but I
+expect that few readers have heard of it.)
+
+Objects have individuality, and multiple names (in multiple scopes) can be bound
+to the same object.  This is known as aliasing in other languages.  This is
+usually not appreciated on a first glance at Python, and can be safely ignored
+when dealing with immutable basic types (numbers, strings, tuples).  However,
+aliasing has an (intended!) effect on the semantics of Python code involving
+mutable objects such as lists, dictionaries, and most types representing
+entities outside the program (files, windows, etc.).  This is usually used to
+the benefit of the program, since aliases behave like pointers in some respects.
+For example, passing an object is cheap since only a pointer is passed by the
+implementation; and if a function modifies an object passed as an argument, the
+caller will see the change --- this eliminates the need for two different
+argument passing mechanisms as in Pascal.
+
+
+.. _tut-scopes:
+
+Python Scopes and Name Spaces
+=============================
+
+Before introducing classes, I first have to tell you something about Python's
+scope rules.  Class definitions play some neat tricks with namespaces, and you
+need to know how scopes and namespaces work to fully understand what's going on.
+Incidentally, knowledge about this subject is useful for any advanced Python
+programmer.
+
+Let's begin with some definitions.
+
+A *namespace* is a mapping from names to objects.  Most namespaces are currently
+implemented as Python dictionaries, but that's normally not noticeable in any
+way (except for performance), and it may change in the future.  Examples of
+namespaces are: the set of built-in names (functions such as :func:`abs`, and
+built-in exception names); the global names in a module; and the local names in
+a function invocation.  In a sense the set of attributes of an object also form
+a namespace.  The important thing to know about namespaces is that there is
+absolutely no relation between names in different namespaces; for instance, two
+different modules may both define a function "maximize" without confusion ---
+users of the modules must prefix it with the module name.
+
+By the way, I use the word *attribute* for any name following a dot --- for
+example, in the expression ``z.real``, ``real`` is an attribute of the object
+``z``.  Strictly speaking, references to names in modules are attribute
+references: in the expression ``modname.funcname``, ``modname`` is a module
+object and ``funcname`` is an attribute of it.  In this case there happens to be
+a straightforward mapping between the module's attributes and the global names
+defined in the module: they share the same namespace!  [#]_
+
+Attributes may be read-only or writable.  In the latter case, assignment to
+attributes is possible.  Module attributes are writable: you can write
+``modname.the_answer = 42``.  Writable attributes may also be deleted with the
+:keyword:`del` statement.  For example, ``del modname.the_answer`` will remove
+the attribute :attr:`the_answer` from the object named by ``modname``.
+
+Name spaces are created at different moments and have different lifetimes.  The
+namespace containing the built-in names is created when the Python interpreter
+starts up, and is never deleted.  The global namespace for a module is created
+when the module definition is read in; normally, module namespaces also last
+until the interpreter quits.  The statements executed by the top-level
+invocation of the interpreter, either read from a script file or interactively,
+are considered part of a module called :mod:`__main__`, so they have their own
+global namespace.  (The built-in names actually also live in a module; this is
+called :mod:`__builtin__`.)
+
+The local namespace for a function is created when the function is called, and
+deleted when the function returns or raises an exception that is not handled
+within the function.  (Actually, forgetting would be a better way to describe
+what actually happens.)  Of course, recursive invocations each have their own
+local namespace.
+
+A *scope* is a textual region of a Python program where a namespace is directly
+accessible.  "Directly accessible" here means that an unqualified reference to a
+name attempts to find the name in the namespace.
+
+Although scopes are determined statically, they are used dynamically. At any
+time during execution, there are at least three nested scopes whose namespaces
+are directly accessible: the innermost scope, which is searched first, contains
+the local names; the namespaces of any enclosing functions, which are searched
+starting with the nearest enclosing scope; the middle scope, searched next,
+contains the current module's global names; and the outermost scope (searched
+last) is the namespace containing built-in names.
+
+If a name is declared global, then all references and assignments go directly to
+the middle scope containing the module's global names. Otherwise, all variables
+found outside of the innermost scope are read-only (an attempt to write to such
+a variable will simply create a *new* local variable in the innermost scope,
+leaving the identically named outer variable unchanged).
+
+Usually, the local scope references the local names of the (textually) current
+function.  Outside functions, the local scope references the same namespace as
+the global scope: the module's namespace. Class definitions place yet another
+namespace in the local scope.
+
+It is important to realize that scopes are determined textually: the global
+scope of a function defined in a module is that module's namespace, no matter
+from where or by what alias the function is called.  On the other hand, the
+actual search for names is done dynamically, at run time --- however, the
+language definition is evolving towards static name resolution, at "compile"
+time, so don't rely on dynamic name resolution!  (In fact, local variables are
+already determined statically.)
+
+A special quirk of Python is that assignments always go into the innermost
+scope.  Assignments do not copy data --- they just bind names to objects.  The
+same is true for deletions: the statement ``del x`` removes the binding of ``x``
+from the namespace referenced by the local scope.  In fact, all operations that
+introduce new names use the local scope: in particular, import statements and
+function definitions bind the module or function name in the local scope.  (The
+:keyword:`global` statement can be used to indicate that particular variables
+live in the global scope.)
+
+
+.. _tut-firstclasses:
+
+A First Look at Classes
+=======================
+
+Classes introduce a little bit of new syntax, three new object types, and some
+new semantics.
+
+
+.. _tut-classdefinition:
+
+Class Definition Syntax
+-----------------------
+
+The simplest form of class definition looks like this::
+
+   class ClassName:
+       <statement-1>
+       .
+       .
+       .
+       <statement-N>
+
+Class definitions, like function definitions (:keyword:`def` statements) must be
+executed before they have any effect.  (You could conceivably place a class
+definition in a branch of an :keyword:`if` statement, or inside a function.)
+
+In practice, the statements inside a class definition will usually be function
+definitions, but other statements are allowed, and sometimes useful --- we'll
+come back to this later.  The function definitions inside a class normally have
+a peculiar form of argument list, dictated by the calling conventions for
+methods --- again, this is explained later.
+
+When a class definition is entered, a new namespace is created, and used as the
+local scope --- thus, all assignments to local variables go into this new
+namespace.  In particular, function definitions bind the name of the new
+function here.
+
+When a class definition is left normally (via the end), a *class object* is
+created.  This is basically a wrapper around the contents of the namespace
+created by the class definition; we'll learn more about class objects in the
+next section.  The original local scope (the one in effect just before the class
+definition was entered) is reinstated, and the class object is bound here to the
+class name given in the class definition header (:class:`ClassName` in the
+example).
+
+
+.. _tut-classobjects:
+
+Class Objects
+-------------
+
+Class objects support two kinds of operations: attribute references and
+instantiation.
+
+*Attribute references* use the standard syntax used for all attribute references
+in Python: ``obj.name``.  Valid attribute names are all the names that were in
+the class's namespace when the class object was created.  So, if the class
+definition looked like this::
+
+   class MyClass:
+       "A simple example class"
+       i = 12345
+       def f(self):
+           return 'hello world'
+
+then ``MyClass.i`` and ``MyClass.f`` are valid attribute references, returning
+an integer and a function object, respectively. Class attributes can also be
+assigned to, so you can change the value of ``MyClass.i`` by assignment.
+:attr:`__doc__` is also a valid attribute, returning the docstring belonging to
+the class: ``"A simple example class"``.
+
+Class *instantiation* uses function notation.  Just pretend that the class
+object is a parameterless function that returns a new instance of the class.
+For example (assuming the above class)::
+
+   x = MyClass()
+
+creates a new *instance* of the class and assigns this object to the local
+variable ``x``.
+
+The instantiation operation ("calling" a class object) creates an empty object.
+Many classes like to create objects with instances customized to a specific
+initial state. Therefore a class may define a special method named
+:meth:`__init__`, like this::
+
+   def __init__(self):
+       self.data = []
+
+When a class defines an :meth:`__init__` method, class instantiation
+automatically invokes :meth:`__init__` for the newly-created class instance.  So
+in this example, a new, initialized instance can be obtained by::
+
+   x = MyClass()
+
+Of course, the :meth:`__init__` method may have arguments for greater
+flexibility.  In that case, arguments given to the class instantiation operator
+are passed on to :meth:`__init__`.  For example, ::
+
+   >>> class Complex:
+   ...     def __init__(self, realpart, imagpart):
+   ...         self.r = realpart
+   ...         self.i = imagpart
+   ... 
+   >>> x = Complex(3.0, -4.5)
+   >>> x.r, x.i
+   (3.0, -4.5)
+
+
+.. _tut-instanceobjects:
+
+Instance Objects
+----------------
+
+Now what can we do with instance objects?  The only operations understood by
+instance objects are attribute references.  There are two kinds of valid
+attribute names, data attributes and methods.
+
+*data attributes* correspond to "instance variables" in Smalltalk, and to "data
+members" in C++.  Data attributes need not be declared; like local variables,
+they spring into existence when they are first assigned to.  For example, if
+``x`` is the instance of :class:`MyClass` created above, the following piece of
+code will print the value ``16``, without leaving a trace::
+
+   x.counter = 1
+   while x.counter < 10:
+       x.counter = x.counter * 2
+   print x.counter
+   del x.counter
+
+The other kind of instance attribute reference is a *method*. A method is a
+function that "belongs to" an object.  (In Python, the term method is not unique
+to class instances: other object types can have methods as well.  For example,
+list objects have methods called append, insert, remove, sort, and so on.
+However, in the following discussion, we'll use the term method exclusively to
+mean methods of class instance objects, unless explicitly stated otherwise.)
+
+.. index:: object: method
+
+Valid method names of an instance object depend on its class.  By definition,
+all attributes of a class that are function  objects define corresponding
+methods of its instances.  So in our example, ``x.f`` is a valid method
+reference, since ``MyClass.f`` is a function, but ``x.i`` is not, since
+``MyClass.i`` is not.  But ``x.f`` is not the same thing as ``MyClass.f`` --- it
+is a *method object*, not a function object.
+
+
+.. _tut-methodobjects:
+
+Method Objects
+--------------
+
+Usually, a method is called right after it is bound::
+
+   x.f()
+
+In the :class:`MyClass` example, this will return the string ``'hello world'``.
+However, it is not necessary to call a method right away: ``x.f`` is a method
+object, and can be stored away and called at a later time.  For example::
+
+   xf = x.f
+   while True:
+       print xf()
+
+will continue to print ``hello world`` until the end of time.
+
+What exactly happens when a method is called?  You may have noticed that
+``x.f()`` was called without an argument above, even though the function
+definition for :meth:`f` specified an argument.  What happened to the argument?
+Surely Python raises an exception when a function that requires an argument is
+called without any --- even if the argument isn't actually used...
+
+Actually, you may have guessed the answer: the special thing about methods is
+that the object is passed as the first argument of the function.  In our
+example, the call ``x.f()`` is exactly equivalent to ``MyClass.f(x)``.  In
+general, calling a method with a list of *n* arguments is equivalent to calling
+the corresponding function with an argument list that is created by inserting
+the method's object before the first argument.
+
+If you still don't understand how methods work, a look at the implementation can
+perhaps clarify matters.  When an instance attribute is referenced that isn't a
+data attribute, its class is searched.  If the name denotes a valid class
+attribute that is a function object, a method object is created by packing
+(pointers to) the instance object and the function object just found together in
+an abstract object: this is the method object.  When the method object is called
+with an argument list, it is unpacked again, a new argument list is constructed
+from the instance object and the original argument list, and the function object
+is called with this new argument list.
+
+
+.. _tut-remarks:
+
+Random Remarks
+==============
+
+.. % [These should perhaps be placed more carefully...]
+
+Data attributes override method attributes with the same name; to avoid
+accidental name conflicts, which may cause hard-to-find bugs in large programs,
+it is wise to use some kind of convention that minimizes the chance of
+conflicts.  Possible conventions include capitalizing method names, prefixing
+data attribute names with a small unique string (perhaps just an underscore), or
+using verbs for methods and nouns for data attributes.
+
+Data attributes may be referenced by methods as well as by ordinary users
+("clients") of an object.  In other words, classes are not usable to implement
+pure abstract data types.  In fact, nothing in Python makes it possible to
+enforce data hiding --- it is all based upon convention.  (On the other hand,
+the Python implementation, written in C, can completely hide implementation
+details and control access to an object if necessary; this can be used by
+extensions to Python written in C.)
+
+Clients should use data attributes with care --- clients may mess up invariants
+maintained by the methods by stamping on their data attributes.  Note that
+clients may add data attributes of their own to an instance object without
+affecting the validity of the methods, as long as name conflicts are avoided ---
+again, a naming convention can save a lot of headaches here.
+
+There is no shorthand for referencing data attributes (or other methods!) from
+within methods.  I find that this actually increases the readability of methods:
+there is no chance of confusing local variables and instance variables when
+glancing through a method.
+
+Often, the first argument of a method is called ``self``.  This is nothing more
+than a convention: the name ``self`` has absolutely no special meaning to
+Python.  (Note, however, that by not following the convention your code may be
+less readable to other Python programmers, and it is also conceivable that a
+*class browser* program might be written that relies upon such a convention.)
+
+Any function object that is a class attribute defines a method for instances of
+that class.  It is not necessary that the function definition is textually
+enclosed in the class definition: assigning a function object to a local
+variable in the class is also ok.  For example::
+
+   # Function defined outside the class
+   def f1(self, x, y):
+       return min(x, x+y)
+
+   class C:
+       f = f1
+       def g(self):
+           return 'hello world'
+       h = g
+
+Now ``f``, ``g`` and ``h`` are all attributes of class :class:`C` that refer to
+function objects, and consequently they are all methods of instances of
+:class:`C` --- ``h`` being exactly equivalent to ``g``.  Note that this practice
+usually only serves to confuse the reader of a program.
+
+Methods may call other methods by using method attributes of the ``self``
+argument::
+
+   class Bag:
+       def __init__(self):
+           self.data = []
+       def add(self, x):
+           self.data.append(x)
+       def addtwice(self, x):
+           self.add(x)
+           self.add(x)
+
+Methods may reference global names in the same way as ordinary functions.  The
+global scope associated with a method is the module containing the class
+definition.  (The class itself is never used as a global scope!)  While one
+rarely encounters a good reason for using global data in a method, there are
+many legitimate uses of the global scope: for one thing, functions and modules
+imported into the global scope can be used by methods, as well as functions and
+classes defined in it.  Usually, the class containing the method is itself
+defined in this global scope, and in the next section we'll find some good
+reasons why a method would want to reference its own class!
+
+
+.. _tut-inheritance:
+
+Inheritance
+===========
+
+Of course, a language feature would not be worthy of the name "class" without
+supporting inheritance.  The syntax for a derived class definition looks like
+this::
+
+   class DerivedClassName(BaseClassName):
+       <statement-1>
+       .
+       .
+       .
+       <statement-N>
+
+The name :class:`BaseClassName` must be defined in a scope containing the
+derived class definition.  In place of a base class name, other arbitrary
+expressions are also allowed.  This can be useful, for example, when the base
+class is defined in another module::
+
+   class DerivedClassName(modname.BaseClassName):
+
+Execution of a derived class definition proceeds the same as for a base class.
+When the class object is constructed, the base class is remembered.  This is
+used for resolving attribute references: if a requested attribute is not found
+in the class, the search proceeds to look in the base class.  This rule is
+applied recursively if the base class itself is derived from some other class.
+
+There's nothing special about instantiation of derived classes:
+``DerivedClassName()`` creates a new instance of the class.  Method references
+are resolved as follows: the corresponding class attribute is searched,
+descending down the chain of base classes if necessary, and the method reference
+is valid if this yields a function object.
+
+Derived classes may override methods of their base classes.  Because methods
+have no special privileges when calling other methods of the same object, a
+method of a base class that calls another method defined in the same base class
+may end up calling a method of a derived class that overrides it.  (For C++
+programmers: all methods in Python are effectively :keyword:`virtual`.)
+
+An overriding method in a derived class may in fact want to extend rather than
+simply replace the base class method of the same name. There is a simple way to
+call the base class method directly: just call ``BaseClassName.methodname(self,
+arguments)``.  This is occasionally useful to clients as well.  (Note that this
+only works if the base class is defined or imported directly in the global
+scope.)
+
+
+.. _tut-multiple:
+
+Multiple Inheritance
+--------------------
+
+Python supports a limited form of multiple inheritance as well.  A class
+definition with multiple base classes looks like this::
+
+   class DerivedClassName(Base1, Base2, Base3):
+       <statement-1>
+       .
+       .
+       .
+       <statement-N>
+
+For old-style classes, the only rule is depth-first, left-to-right.  Thus, if an
+attribute is not found in :class:`DerivedClassName`, it is searched in
+:class:`Base1`, then (recursively) in the base classes of :class:`Base1`, and
+only if it is not found there, it is searched in :class:`Base2`, and so on.
+
+(To some people breadth first --- searching :class:`Base2` and :class:`Base3`
+before the base classes of :class:`Base1` --- looks more natural.  However, this
+would require you to know whether a particular attribute of :class:`Base1` is
+actually defined in :class:`Base1` or in one of its base classes before you can
+figure out the consequences of a name conflict with an attribute of
+:class:`Base2`.  The depth-first rule makes no differences between direct and
+inherited attributes of :class:`Base1`.)
+
+For new-style classes, the method resolution order changes dynamically to
+support cooperative calls to :func:`super`.  This approach is known in some
+other multiple-inheritance languages as call-next-method and is more powerful
+than the super call found in single-inheritance languages.
+
+With new-style classes, dynamic ordering is necessary because all  cases of
+multiple inheritance exhibit one or more diamond relationships (where one at
+least one of the parent classes can be accessed through multiple paths from the
+bottommost class).  For example, all new-style classes inherit from
+:class:`object`, so any case of multiple inheritance provides more than one path
+to reach :class:`object`.  To keep the base classes from being accessed more
+than once, the dynamic algorithm linearizes the search order in a way that
+preserves the left-to-right ordering specified in each class, that calls each
+parent only once, and that is monotonic (meaning that a class can be subclassed
+without affecting the precedence order of its parents).  Taken together, these
+properties make it possible to design reliable and extensible classes with
+multiple inheritance.  For more detail, see
+http://www.python.org/download/releases/2.3/mro/.
+
+
+.. _tut-private:
+
+Private Variables
+=================
+
+There is limited support for class-private identifiers.  Any identifier of the
+form ``__spam`` (at least two leading underscores, at most one trailing
+underscore) is textually replaced with ``_classname__spam``, where ``classname``
+is the current class name with leading underscore(s) stripped.  This mangling is
+done without regard to the syntactic position of the identifier, so it can be
+used to define class-private instance and class variables, methods, variables
+stored in globals, and even variables stored in instances. private to this class
+on instances of *other* classes.  Truncation may occur when the mangled name
+would be longer than 255 characters. Outside classes, or when the class name
+consists of only underscores, no mangling occurs.
+
+Name mangling is intended to give classes an easy way to define "private"
+instance variables and methods, without having to worry about instance variables
+defined by derived classes, or mucking with instance variables by code outside
+the class.  Note that the mangling rules are designed mostly to avoid accidents;
+it still is possible for a determined soul to access or modify a variable that
+is considered private.  This can even be useful in special circumstances, such
+as in the debugger, and that's one reason why this loophole is not closed.
+(Buglet: derivation of a class with the same name as the base class makes use of
+private variables of the base class possible.)
+
+Notice that code passed to ``exec()`` or ``eval()`` does not
+consider the classname of the invoking  class to be the current class; this is
+similar to the effect of the  ``global`` statement, the effect of which is
+likewise restricted to  code that is byte-compiled together.  The same
+restriction applies to ``getattr()``, ``setattr()`` and ``delattr()``, as well
+as when referencing ``__dict__`` directly.
+
+
+.. _tut-odds:
+
+Odds and Ends
+=============
+
+Sometimes it is useful to have a data type similar to the Pascal "record" or C
+"struct", bundling together a few named data items.  An empty class definition
+will do nicely::
+
+   class Employee:
+       pass
+
+   john = Employee() # Create an empty employee record
+
+   # Fill the fields of the record
+   john.name = 'John Doe'
+   john.dept = 'computer lab'
+   john.salary = 1000
+
+A piece of Python code that expects a particular abstract data type can often be
+passed a class that emulates the methods of that data type instead.  For
+instance, if you have a function that formats some data from a file object, you
+can define a class with methods :meth:`read` and :meth:`readline` that get the
+data from a string buffer instead, and pass it as an argument.
+
+.. % (Unfortunately, this
+.. % technique has its limitations: a class can't define operations that
+.. % are accessed by special syntax such as sequence subscripting or
+.. % arithmetic operators, and assigning such a ``pseudo-file'' to
+.. % \code{sys.stdin} will not cause the interpreter to read further input
+.. % from it.)
+
+Instance method objects have attributes, too: ``m.im_self`` is the instance
+object with the method :meth:`m`, and ``m.im_func`` is the function object
+corresponding to the method.
+
+
+.. _tut-exceptionclasses:
+
+Exceptions Are Classes Too
+==========================
+
+User-defined exceptions are identified by classes as well.  Using this mechanism
+it is possible to create extensible hierarchies of exceptions.
+
+There are two new valid (semantic) forms for the raise statement::
+
+   raise Class, instance
+
+   raise instance
+
+In the first form, ``instance`` must be an instance of :class:`Class` or of a
+class derived from it.  The second form is a shorthand for::
+
+   raise instance.__class__, instance
+
+A class in an except clause is compatible with an exception if it is the same
+class or a base class thereof (but not the other way around --- an except clause
+listing a derived class is not compatible with a base class).  For example, the
+following code will print B, C, D in that order::
+
+   class B:
+       pass
+   class C(B):
+       pass
+   class D(C):
+       pass
+
+   for c in [B, C, D]:
+       try:
+           raise c()
+       except D:
+           print "D"
+       except C:
+           print "C"
+       except B:
+           print "B"
+
+Note that if the except clauses were reversed (with ``except B`` first), it
+would have printed B, B, B --- the first matching except clause is triggered.
+
+When an error message is printed for an unhandled exception, the exception's
+class name is printed, then a colon and a space, and finally the instance
+converted to a string using the built-in function :func:`str`.
+
+
+.. _tut-iterators:
+
+Iterators
+=========
+
+By now you have probably noticed that most container objects can be looped over
+using a :keyword:`for` statement::
+
+   for element in [1, 2, 3]:
+       print element
+   for element in (1, 2, 3):
+       print element
+   for key in {'one':1, 'two':2}:
+       print key
+   for char in "123":
+       print char
+   for line in open("myfile.txt"):
+       print line
+
+This style of access is clear, concise, and convenient.  The use of iterators
+pervades and unifies Python.  Behind the scenes, the :keyword:`for` statement
+calls :func:`iter` on the container object.  The function returns an iterator
+object that defines the method :meth:`__next__` which accesses elements in the
+container one at a time.  When there are no more elements, :meth:`__next__`
+raises a :exc:`StopIteration` exception which tells the :keyword:`for` loop to
+terminate.  You can call the :meth:`__next__` method using the :func:`next`
+builtin; this example shows how it all works::
+
+   >>> s = 'abc'
+   >>> it = iter(s)
+   >>> it
+   <iterator object at 0x00A1DB50>
+   >>> next(it)
+   'a'
+   >>> next(it)
+   'b'
+   >>> next(it)
+   'c'
+   >>> next(it)
+
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+       next(it)
+   StopIteration
+
+Having seen the mechanics behind the iterator protocol, it is easy to add
+iterator behavior to your classes.  Define a :meth:`__iter__` method which
+returns an object with a :meth:`__next__` method.  If the class defines
+:meth:`__next__`, then :meth:`__iter__` can just return ``self``::
+
+   class Reverse:
+       "Iterator for looping over a sequence backwards"
+       def __init__(self, data):
+           self.data = data
+           self.index = len(data)
+       def __iter__(self):
+           return self
+       def __next__(self):
+           if self.index == 0:
+               raise StopIteration
+           self.index = self.index - 1
+           return self.data[self.index]
+
+   >>> for char in Reverse('spam'):
+   ...     print char
+   ...
+   m
+   a
+   p
+   s
+
+
+.. _tut-generators:
+
+Generators
+==========
+
+Generators are a simple and powerful tool for creating iterators.  They are
+written like regular functions but use the :keyword:`yield` statement whenever
+they want to return data.  Each time :func:`next` is called on it, the generator
+resumes where it left-off (it remembers all the data values and which statement
+was last executed).  An example shows that generators can be trivially easy to
+create::
+
+   def reverse(data):
+       for index in range(len(data)-1, -1, -1):
+           yield data[index]
+
+   >>> for char in reverse('golf'):
+   ...     print char
+   ...
+   f
+   l
+   o
+   g	
+
+Anything that can be done with generators can also be done with class based
+iterators as described in the previous section.  What makes generators so
+compact is that the :meth:`__iter__` and :meth:`__next__` methods are created
+automatically.
+
+Another key feature is that the local variables and execution state are
+automatically saved between calls.  This made the function easier to write and
+much more clear than an approach using instance variables like ``self.index``
+and ``self.data``.
+
+In addition to automatic method creation and saving program state, when
+generators terminate, they automatically raise :exc:`StopIteration`. In
+combination, these features make it easy to create iterators with no more effort
+than writing a regular function.
+
+
+.. _tut-genexps:
+
+Generator Expressions
+=====================
+
+Some simple generators can be coded succinctly as expressions using a syntax
+similar to list comprehensions but with parentheses instead of brackets.  These
+expressions are designed for situations where the generator is used right away
+by an enclosing function.  Generator expressions are more compact but less
+versatile than full generator definitions and tend to be more memory friendly
+than equivalent list comprehensions.
+
+Examples::
+
+   >>> sum(i*i for i in range(10))                 # sum of squares
+   285
+
+   >>> xvec = [10, 20, 30]
+   >>> yvec = [7, 5, 3]
+   >>> sum(x*y for x,y in zip(xvec, yvec))         # dot product
+   260
+
+   >>> from math import pi, sin
+   >>> sine_table = dict((x, sin(x*pi/180)) for x in range(0, 91))
+
+   >>> unique_words = set(word  for line in page  for word in line.split())
+
+   >>> valedictorian = max((student.gpa, student.name) for student in graduates)
+
+   >>> data = 'golf'
+   >>> list(data[i] for i in range(len(data)-1,-1,-1))
+   ['f', 'l', 'o', 'g']
+
+
+
+.. rubric:: Footnotes
+
+.. [#] Except for one thing.  Module objects have a secret read-only attribute called
+   :attr:`__dict__` which returns the dictionary used to implement the module's
+   namespace; the name :attr:`__dict__` is an attribute but not a global name.
+   Obviously, using this violates the abstraction of namespace implementation, and
+   should be restricted to things like post-mortem debuggers.
+
diff --git a/Doc/tutorial/controlflow.rst b/Doc/tutorial/controlflow.rst
new file mode 100644
index 0000000..f6f41b3
--- /dev/null
+++ b/Doc/tutorial/controlflow.rst
@@ -0,0 +1,574 @@
+.. _tut-morecontrol:
+
+***********************
+More Control Flow Tools
+***********************
+
+Besides the :keyword:`while` statement just introduced, Python knows the usual
+control flow statements known from other languages, with some twists.
+
+
+.. _tut-if:
+
+:keyword:`if` Statements
+========================
+
+Perhaps the most well-known statement type is the :keyword:`if` statement.  For
+example::
+
+   >>> def raw_input(prompt):
+   ...     import sys
+   ...     sys.stdout.write(prompt)
+   ...     sys.stdout.flush()
+   ...     return sys.stdin.readline()
+   ... 
+   >>> x = int(raw_input("Please enter an integer: "))
+   >>> if x < 0:
+   ...      x = 0
+   ...      print 'Negative changed to zero'
+   ... elif x == 0:
+   ...      print 'Zero'
+   ... elif x == 1:
+   ...      print 'Single'
+   ... else:
+   ...      print 'More'
+   ... 
+
+There can be zero or more :keyword:`elif` parts, and the :keyword:`else` part is
+optional.  The keyword ':keyword:`elif`' is short for 'else if', and is useful
+to avoid excessive indentation.  An  :keyword:`if` ... :keyword:`elif` ...
+:keyword:`elif` ... sequence is a substitute for the :keyword:`switch` or
+:keyword:`case` statements found in other languages.
+
+.. % Weird spacings happen here if the wrapping of the source text
+.. % gets changed in the wrong way.
+
+
+.. _tut-for:
+
+:keyword:`for` Statements
+=========================
+
+.. index::
+   statement: for
+   statement: for
+
+The :keyword:`for` statement in Python differs a bit from what you may be used
+to in C or Pascal.  Rather than always iterating over an arithmetic progression
+of numbers (like in Pascal), or giving the user the ability to define both the
+iteration step and halting condition (as C), Python's :keyword:`for` statement
+iterates over the items of any sequence (a list or a string), in the order that
+they appear in the sequence.  For example (no pun intended):
+
+.. % One suggestion was to give a real C example here, but that may only
+.. % serve to confuse non-C programmers.
+
+::
+
+   >>> # Measure some strings:
+   ... a = ['cat', 'window', 'defenestrate']
+   >>> for x in a:
+   ...     print x, len(x)
+   ... 
+   cat 3
+   window 6
+   defenestrate 12
+
+It is not safe to modify the sequence being iterated over in the loop (this can
+only happen for mutable sequence types, such as lists).  If you need to modify
+the list you are iterating over (for example, to duplicate selected items) you
+must iterate over a copy.  The slice notation makes this particularly
+convenient::
+
+   >>> for x in a[:]: # make a slice copy of the entire list
+   ...    if len(x) > 6: a.insert(0, x)
+   ... 
+   >>> a
+   ['defenestrate', 'cat', 'window', 'defenestrate']
+
+
+.. _tut-range:
+
+The :func:`range` Function
+==========================
+
+If you do need to iterate over a sequence of numbers, the built-in function
+:func:`range` comes in handy.  It generates lists containing arithmetic
+progressions::
+
+   >>> range(10)
+   [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]
+
+The given end point is never part of the generated list; ``range(10)`` generates
+a list of 10 values, the legal indices for items of a sequence of length 10.  It
+is possible to let the range start at another number, or to specify a different
+increment (even negative; sometimes this is called the 'step')::
+
+   >>> range(5, 10)
+   [5, 6, 7, 8, 9]
+   >>> range(0, 10, 3)
+   [0, 3, 6, 9]
+   >>> range(-10, -100, -30)
+   [-10, -40, -70]
+
+To iterate over the indices of a sequence, combine :func:`range` and :func:`len`
+as follows::
+
+   >>> a = ['Mary', 'had', 'a', 'little', 'lamb']
+   >>> for i in range(len(a)):
+   ...     print i, a[i]
+   ... 
+   0 Mary
+   1 had
+   2 a
+   3 little
+   4 lamb
+
+
+.. _tut-break:
+
+:keyword:`break` and :keyword:`continue` Statements, and :keyword:`else` Clauses on Loops
+=========================================================================================
+
+The :keyword:`break` statement, like in C, breaks out of the smallest enclosing
+:keyword:`for` or :keyword:`while` loop.
+
+The :keyword:`continue` statement, also borrowed from C, continues with the next
+iteration of the loop.
+
+Loop statements may have an ``else`` clause; it is executed when the loop
+terminates through exhaustion of the list (with :keyword:`for`) or when the
+condition becomes false (with :keyword:`while`), but not when the loop is
+terminated by a :keyword:`break` statement.  This is exemplified by the
+following loop, which searches for prime numbers::
+
+   >>> for n in range(2, 10):
+   ...     for x in range(2, n):
+   ...         if n % x == 0:
+   ...             print n, 'equals', x, '*', n/x
+   ...             break
+   ...     else:
+   ...         # loop fell through without finding a factor
+   ...         print n, 'is a prime number'
+   ... 
+   2 is a prime number
+   3 is a prime number
+   4 equals 2 * 2
+   5 is a prime number
+   6 equals 2 * 3
+   7 is a prime number
+   8 equals 2 * 4
+   9 equals 3 * 3
+
+
+.. _tut-pass:
+
+:keyword:`pass` Statements
+==========================
+
+The :keyword:`pass` statement does nothing. It can be used when a statement is
+required syntactically but the program requires no action. For example::
+
+   >>> while True:
+   ...       pass # Busy-wait for keyboard interrupt
+   ... 
+
+
+.. _tut-functions:
+
+Defining Functions
+==================
+
+We can create a function that writes the Fibonacci series to an arbitrary
+boundary::
+
+   >>> def fib(n):    # write Fibonacci series up to n
+   ...     """Print a Fibonacci series up to n."""
+   ...     a, b = 0, 1
+   ...     while b < n:
+   ...         print b,
+   ...         a, b = b, a+b
+   ... 
+   >>> # Now call the function we just defined:
+   ... fib(2000)
+   1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987 1597
+
+.. index::
+   single: documentation strings
+   single: docstrings
+   single: strings, documentation
+
+The keyword :keyword:`def` introduces a function *definition*.  It must be
+followed by the function name and the parenthesized list of formal parameters.
+The statements that form the body of the function start at the next line, and
+must be indented.  The first statement of the function body can optionally be a
+string literal; this string literal is the function's documentation string, or
+:dfn:`docstring`.
+
+There are tools which use docstrings to automatically produce online or printed
+documentation, or to let the user interactively browse through code; it's good
+practice to include docstrings in code that you write, so try to make a habit of
+it.
+
+The *execution* of a function introduces a new symbol table used for the local
+variables of the function.  More precisely, all variable assignments in a
+function store the value in the local symbol table; whereas variable references
+first look in the local symbol table, then in the global symbol table, and then
+in the table of built-in names. Thus,  global variables cannot be directly
+assigned a value within a function (unless named in a :keyword:`global`
+statement), although they may be referenced.
+
+The actual parameters (arguments) to a function call are introduced in the local
+symbol table of the called function when it is called; thus, arguments are
+passed using *call by value* (where the *value* is always an object *reference*,
+not the value of the object). [#]_ When a function calls another function, a new
+local symbol table is created for that call.
+
+A function definition introduces the function name in the current symbol table.
+The value of the function name has a type that is recognized by the interpreter
+as a user-defined function.  This value can be assigned to another name which
+can then also be used as a function.  This serves as a general renaming
+mechanism::
+
+   >>> fib
+   <function fib at 10042ed0>
+   >>> f = fib
+   >>> f(100)
+   1 1 2 3 5 8 13 21 34 55 89
+
+You might object that ``fib`` is not a function but a procedure.  In Python,
+like in C, procedures are just functions that don't return a value.  In fact,
+technically speaking, procedures do return a value, albeit a rather boring one.
+This value is called ``None`` (it's a built-in name).  Writing the value
+``None`` is normally suppressed by the interpreter if it would be the only value
+written.  You can see it if you really want to::
+
+   >>> print fib(0)
+   None
+
+It is simple to write a function that returns a list of the numbers of the
+Fibonacci series, instead of printing it::
+
+   >>> def fib2(n): # return Fibonacci series up to n
+   ...     """Return a list containing the Fibonacci series up to n."""
+   ...     result = []
+   ...     a, b = 0, 1
+   ...     while b < n:
+   ...         result.append(b)    # see below
+   ...         a, b = b, a+b
+   ...     return result
+   ... 
+   >>> f100 = fib2(100)    # call it
+   >>> f100                # write the result
+   [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
+
+This example, as usual, demonstrates some new Python features:
+
+* The :keyword:`return` statement returns with a value from a function.
+  :keyword:`return` without an expression argument returns ``None``. Falling off
+  the end of a procedure also returns ``None``.
+
+* The statement ``result.append(b)`` calls a *method* of the list object
+  ``result``.  A method is a function that 'belongs' to an object and is named
+  ``obj.methodname``, where ``obj`` is some object (this may be an expression),
+  and ``methodname`` is the name of a method that is defined by the object's type.
+  Different types define different methods.  Methods of different types may have
+  the same name without causing ambiguity.  (It is possible to define your own
+  object types and methods, using *classes*, as discussed later in this tutorial.)
+  The method :meth:`append` shown in the example is defined for list objects; it
+  adds a new element at the end of the list.  In this example it is equivalent to
+  ``result = result + [b]``, but more efficient.
+
+
+.. _tut-defining:
+
+More on Defining Functions
+==========================
+
+It is also possible to define functions with a variable number of arguments.
+There are three forms, which can be combined.
+
+
+.. _tut-defaultargs:
+
+Default Argument Values
+-----------------------
+
+The most useful form is to specify a default value for one or more arguments.
+This creates a function that can be called with fewer arguments than it is
+defined to allow.  For example::
+
+   def raw_input(prompt):
+       import sys
+       sys.stdout.write(prompt)
+       sys.stdout.flush()
+       return sys.stdin.readline()
+
+   def ask_ok(prompt, retries=4, complaint='Yes or no, please!'):
+       while True:
+           ok = raw_input(prompt)
+           if ok in ('y', 'ye', 'yes'): return True
+           if ok in ('n', 'no', 'nop', 'nope'): return False
+           retries = retries - 1
+           if retries < 0: raise IOError, 'refusenik user'
+           print complaint
+
+This function can be called either like this: ``ask_ok('Do you really want to
+quit?')`` or like this: ``ask_ok('OK to overwrite the file?', 2)``.
+
+This example also introduces the :keyword:`in` keyword. This tests whether or
+not a sequence contains a certain value.
+
+The default values are evaluated at the point of function definition in the
+*defining* scope, so that ::
+
+   i = 5
+
+   def f(arg=i):
+       print arg
+
+   i = 6
+   f()
+
+will print ``5``.
+
+**Important warning:**  The default value is evaluated only once. This makes a
+difference when the default is a mutable object such as a list, dictionary, or
+instances of most classes.  For example, the following function accumulates the
+arguments passed to it on subsequent calls::
+
+   def f(a, L=[]):
+       L.append(a)
+       return L
+
+   print f(1)
+   print f(2)
+   print f(3)
+
+This will print ::
+
+   [1]
+   [1, 2]
+   [1, 2, 3]
+
+If you don't want the default to be shared between subsequent calls, you can
+write the function like this instead::
+
+   def f(a, L=None):
+       if L is None:
+           L = []
+       L.append(a)
+       return L
+
+
+.. _tut-keywordargs:
+
+Keyword Arguments
+-----------------
+
+Functions can also be called using keyword arguments of the form ``keyword =
+value``.  For instance, the following function::
+
+   def parrot(voltage, state='a stiff', action='voom', type='Norwegian Blue'):
+       print "-- This parrot wouldn't", action,
+       print "if you put", voltage, "volts through it."
+       print "-- Lovely plumage, the", type
+       print "-- It's", state, "!"
+
+could be called in any of the following ways::
+
+   parrot(1000)
+   parrot(action = 'VOOOOOM', voltage = 1000000)
+   parrot('a thousand', state = 'pushing up the daisies')
+   parrot('a million', 'bereft of life', 'jump')
+
+but the following calls would all be invalid::
+
+   parrot()                     # required argument missing
+   parrot(voltage=5.0, 'dead')  # non-keyword argument following keyword
+   parrot(110, voltage=220)     # duplicate value for argument
+   parrot(actor='John Cleese')  # unknown keyword
+
+In general, an argument list must have any positional arguments followed by any
+keyword arguments, where the keywords must be chosen from the formal parameter
+names.  It's not important whether a formal parameter has a default value or
+not.  No argument may receive a value more than once --- formal parameter names
+corresponding to positional arguments cannot be used as keywords in the same
+calls. Here's an example that fails due to this restriction::
+
+   >>> def function(a):
+   ...     pass
+   ... 
+   >>> function(0, a=0)
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   TypeError: function() got multiple values for keyword argument 'a'
+
+When a final formal parameter of the form ``**name`` is present, it receives a
+dictionary (see :ref:`typesmapping`) containing all keyword arguments except for
+those corresponding to a formal parameter.  This may be combined with a formal
+parameter of the form ``*name`` (described in the next subsection) which
+receives a tuple containing the positional arguments beyond the formal parameter
+list.  (``*name`` must occur before ``**name``.) For example, if we define a
+function like this::
+
+   def cheeseshop(kind, *arguments, **keywords):
+       print "-- Do you have any", kind, '?'
+       print "-- I'm sorry, we're all out of", kind
+       for arg in arguments: print arg
+       print '-'*40
+       keys = keywords.keys()
+       keys.sort()
+       for kw in keys: print kw, ':', keywords[kw]
+
+It could be called like this::
+
+   cheeseshop('Limburger', "It's very runny, sir.",
+              "It's really very, VERY runny, sir.",
+              client='John Cleese',
+              shopkeeper='Michael Palin',
+              sketch='Cheese Shop Sketch')
+
+and of course it would print::
+
+   -- Do you have any Limburger ?
+   -- I'm sorry, we're all out of Limburger
+   It's very runny, sir.
+   It's really very, VERY runny, sir.
+   ----------------------------------------
+   client : John Cleese
+   shopkeeper : Michael Palin
+   sketch : Cheese Shop Sketch
+
+Note that the :meth:`sort` method of the list of keyword argument names is
+called before printing the contents of the ``keywords`` dictionary; if this is
+not done, the order in which the arguments are printed is undefined.
+
+
+.. _tut-arbitraryargs:
+
+Arbitrary Argument Lists
+------------------------
+
+Finally, the least frequently used option is to specify that a function can be
+called with an arbitrary number of arguments.  These arguments will be wrapped
+up in a tuple.  Before the variable number of arguments, zero or more normal
+arguments may occur. ::
+
+   def fprintf(file, format, *args):
+       file.write(format % args)
+
+
+.. _tut-unpacking-arguments:
+
+Unpacking Argument Lists
+------------------------
+
+The reverse situation occurs when the arguments are already in a list or tuple
+but need to be unpacked for a function call requiring separate positional
+arguments.  For instance, the built-in :func:`range` function expects separate
+*start* and *stop* arguments.  If they are not available separately, write the
+function call with the  ``*``\ -operator to unpack the arguments out of a list
+or tuple::
+
+   >>> range(3, 6)             # normal call with separate arguments
+   [3, 4, 5]
+   >>> args = [3, 6]
+   >>> range(*args)            # call with arguments unpacked from a list
+   [3, 4, 5]
+
+In the same fashion, dictionaries can deliver keyword arguments with the ``**``\
+-operator::
+
+   >>> def parrot(voltage, state='a stiff', action='voom'):
+   ...     print "-- This parrot wouldn't", action,
+   ...     print "if you put", voltage, "volts through it.",
+   ...     print "E's", state, "!"
+   ...
+   >>> d = {"voltage": "four million", "state": "bleedin' demised", "action": "VOOM"}
+   >>> parrot(**d)
+   -- This parrot wouldn't VOOM if you put four million volts through it. E's bleedin' demised !
+
+
+.. _tut-lambda:
+
+Lambda Forms
+------------
+
+By popular demand, a few features commonly found in functional programming
+languages like Lisp have been added to Python.  With the :keyword:`lambda`
+keyword, small anonymous functions can be created. Here's a function that
+returns the sum of its two arguments: ``lambda a, b: a+b``.  Lambda forms can be
+used wherever function objects are required.  They are syntactically restricted
+to a single expression.  Semantically, they are just syntactic sugar for a
+normal function definition.  Like nested function definitions, lambda forms can
+reference variables from the containing scope::
+
+   >>> def make_incrementor(n):
+   ...     return lambda x: x + n
+   ...
+   >>> f = make_incrementor(42)
+   >>> f(0)
+   42
+   >>> f(1)
+   43
+
+
+.. _tut-docstrings:
+
+Documentation Strings
+---------------------
+
+.. index::
+   single: docstrings
+   single: documentation strings
+   single: strings, documentation
+
+There are emerging conventions about the content and formatting of documentation
+strings.
+
+The first line should always be a short, concise summary of the object's
+purpose.  For brevity, it should not explicitly state the object's name or type,
+since these are available by other means (except if the name happens to be a
+verb describing a function's operation).  This line should begin with a capital
+letter and end with a period.
+
+If there are more lines in the documentation string, the second line should be
+blank, visually separating the summary from the rest of the description.  The
+following lines should be one or more paragraphs describing the object's calling
+conventions, its side effects, etc.
+
+The Python parser does not strip indentation from multi-line string literals in
+Python, so tools that process documentation have to strip indentation if
+desired.  This is done using the following convention. The first non-blank line
+*after* the first line of the string determines the amount of indentation for
+the entire documentation string.  (We can't use the first line since it is
+generally adjacent to the string's opening quotes so its indentation is not
+apparent in the string literal.)  Whitespace "equivalent" to this indentation is
+then stripped from the start of all lines of the string.  Lines that are
+indented less should not occur, but if they occur all their leading whitespace
+should be stripped.  Equivalence of whitespace should be tested after expansion
+of tabs (to 8 spaces, normally).
+
+Here is an example of a multi-line docstring::
+
+   >>> def my_function():
+   ...     """Do nothing, but document it.
+   ... 
+   ...     No, really, it doesn't do anything.
+   ...     """
+   ...     pass
+   ... 
+   >>> print my_function.__doc__
+   Do nothing, but document it.
+
+       No, really, it doesn't do anything.
+
+
+
+.. rubric:: Footnotes
+
+.. [#] Actually, *call by object reference* would be a better description, since if a
+   mutable object is passed, the caller will see any changes the callee makes to it
+   (items inserted into a list).
+
diff --git a/Doc/tutorial/datastructures.rst b/Doc/tutorial/datastructures.rst
new file mode 100644
index 0000000..d65e55b
--- /dev/null
+++ b/Doc/tutorial/datastructures.rst
@@ -0,0 +1,586 @@
+.. _tut-structures:
+
+***************
+Data Structures
+***************
+
+This chapter describes some things you've learned about already in more detail,
+and adds some new things as well.
+
+
+.. _tut-morelists:
+
+More on Lists
+=============
+
+The list data type has some more methods.  Here are all of the methods of list
+objects:
+
+
+.. method:: list.append(x)
+
+   Add an item to the end of the list; equivalent to ``a[len(a):] = [x]``.
+
+
+.. method:: list.extend(L)
+
+   Extend the list by appending all the items in the given list; equivalent to
+   ``a[len(a):] = L``.
+
+
+.. method:: list.insert(i, x)
+
+   Insert an item at a given position.  The first argument is the index of the
+   element before which to insert, so ``a.insert(0, x)`` inserts at the front of
+   the list, and ``a.insert(len(a), x)`` is equivalent to ``a.append(x)``.
+
+
+.. method:: list.remove(x)
+
+   Remove the first item from the list whose value is *x*. It is an error if there
+   is no such item.
+
+
+.. method:: list.pop([i])
+
+   Remove the item at the given position in the list, and return it.  If no index
+   is specified, ``a.pop()`` removes and returns the last item in the list.  (The
+   square brackets around the *i* in the method signature denote that the parameter
+   is optional, not that you should type square brackets at that position.  You
+   will see this notation frequently in the Python Library Reference.)
+
+
+.. method:: list.index(x)
+
+   Return the index in the list of the first item whose value is *x*. It is an
+   error if there is no such item.
+
+
+.. method:: list.count(x)
+
+   Return the number of times *x* appears in the list.
+
+
+.. method:: list.sort()
+
+   Sort the items of the list, in place.
+
+
+.. method:: list.reverse()
+
+   Reverse the elements of the list, in place.
+
+An example that uses most of the list methods::
+
+   >>> a = [66.25, 333, 333, 1, 1234.5]
+   >>> print a.count(333), a.count(66.25), a.count('x')
+   2 1 0
+   >>> a.insert(2, -1)
+   >>> a.append(333)
+   >>> a
+   [66.25, 333, -1, 333, 1, 1234.5, 333]
+   >>> a.index(333)
+   1
+   >>> a.remove(333)
+   >>> a
+   [66.25, -1, 333, 1, 1234.5, 333]
+   >>> a.reverse()
+   >>> a
+   [333, 1234.5, 1, 333, -1, 66.25]
+   >>> a.sort()
+   >>> a
+   [-1, 1, 66.25, 333, 333, 1234.5]
+
+
+.. _tut-lists-as-stacks:
+
+Using Lists as Stacks
+---------------------
+
+.. sectionauthor:: Ka-Ping Yee <ping@lfw.org>
+
+
+The list methods make it very easy to use a list as a stack, where the last
+element added is the first element retrieved ("last-in, first-out").  To add an
+item to the top of the stack, use :meth:`append`.  To retrieve an item from the
+top of the stack, use :meth:`pop` without an explicit index.  For example::
+
+   >>> stack = [3, 4, 5]
+   >>> stack.append(6)
+   >>> stack.append(7)
+   >>> stack
+   [3, 4, 5, 6, 7]
+   >>> stack.pop()
+   7
+   >>> stack
+   [3, 4, 5, 6]
+   >>> stack.pop()
+   6
+   >>> stack.pop()
+   5
+   >>> stack
+   [3, 4]
+
+
+.. _tut-lists-as-queues:
+
+Using Lists as Queues
+---------------------
+
+.. sectionauthor:: Ka-Ping Yee <ping@lfw.org>
+
+
+You can also use a list conveniently as a queue, where the first element added
+is the first element retrieved ("first-in, first-out").  To add an item to the
+back of the queue, use :meth:`append`.  To retrieve an item from the front of
+the queue, use :meth:`pop` with ``0`` as the index.  For example::
+
+   >>> queue = ["Eric", "John", "Michael"]
+   >>> queue.append("Terry")           # Terry arrives
+   >>> queue.append("Graham")          # Graham arrives
+   >>> queue.pop(0)
+   'Eric'
+   >>> queue.pop(0)
+   'John'
+   >>> queue
+   ['Michael', 'Terry', 'Graham']
+
+
+.. _tut-functional:
+
+Functional Programming Tools
+----------------------------
+
+There are two built-in functions that are very useful when used with lists:
+:func:`filter` and :func:`map`.
+
+``filter(function, sequence)`` returns a sequence consisting of those items from
+the sequence for which ``function(item)`` is true. If *sequence* is a
+:class:`string` or :class:`tuple`, the result will be of the same type;
+otherwise, it is always a :class:`list`. For example, to compute some primes::
+
+   >>> def f(x): return x % 2 != 0 and x % 3 != 0
+   ...
+   >>> filter(f, range(2, 25))
+   [5, 7, 11, 13, 17, 19, 23]
+
+``map(function, sequence)`` calls ``function(item)`` for each of the sequence's
+items and returns a list of the return values.  For example, to compute some
+cubes::
+
+   >>> def cube(x): return x*x*x
+   ...
+   >>> map(cube, range(1, 11))
+   [1, 8, 27, 64, 125, 216, 343, 512, 729, 1000]
+
+More than one sequence may be passed; the function must then have as many
+arguments as there are sequences and is called with the corresponding item from
+each sequence (or ``None`` if some sequence is shorter than another).  For
+example::
+
+   >>> seq = range(8)
+   >>> def add(x, y): return x+y
+   ...
+   >>> map(add, seq, seq)
+   [0, 2, 4, 6, 8, 10, 12, 14]
+
+.. versionadded:: 2.3
+
+
+List Comprehensions
+-------------------
+
+List comprehensions provide a concise way to create lists without resorting to
+use of :func:`map`, :func:`filter` and/or :keyword:`lambda`. The resulting list
+definition tends often to be clearer than lists built using those constructs.
+Each list comprehension consists of an expression followed by a :keyword:`for`
+clause, then zero or more :keyword:`for` or :keyword:`if` clauses.  The result
+will be a list resulting from evaluating the expression in the context of the
+:keyword:`for` and :keyword:`if` clauses which follow it.  If the expression
+would evaluate to a tuple, it must be parenthesized. ::
+
+   >>> freshfruit = ['  banana', '  loganberry ', 'passion fruit  ']
+   >>> [weapon.strip() for weapon in freshfruit]
+   ['banana', 'loganberry', 'passion fruit']
+   >>> vec = [2, 4, 6]
+   >>> [3*x for x in vec]
+   [6, 12, 18]
+   >>> [3*x for x in vec if x > 3]
+   [12, 18]
+   >>> [3*x for x in vec if x < 2]
+   []
+   >>> [[x,x**2] for x in vec]
+   [[2, 4], [4, 16], [6, 36]]
+   >>> [x, x**2 for x in vec]	# error - parens required for tuples
+     File "<stdin>", line 1, in ?
+       [x, x**2 for x in vec]
+                  ^
+   SyntaxError: invalid syntax
+   >>> [(x, x**2) for x in vec]
+   [(2, 4), (4, 16), (6, 36)]
+   >>> vec1 = [2, 4, 6]
+   >>> vec2 = [4, 3, -9]
+   >>> [x*y for x in vec1 for y in vec2]
+   [8, 6, -18, 16, 12, -36, 24, 18, -54]
+   >>> [x+y for x in vec1 for y in vec2]
+   [6, 5, -7, 8, 7, -5, 10, 9, -3]
+   >>> [vec1[i]*vec2[i] for i in range(len(vec1))]
+   [8, 12, -54]
+
+List comprehensions are much more flexible than :func:`map` and can be applied
+to complex expressions and nested functions::
+
+   >>> [str(round(355/113.0, i)) for i in range(1,6)]
+   ['3.1', '3.14', '3.142', '3.1416', '3.14159']
+
+
+.. _tut-del:
+
+The :keyword:`del` statement
+============================
+
+There is a way to remove an item from a list given its index instead of its
+value: the :keyword:`del` statement.  This differs from the :meth:`pop` method
+which returns a value.  The :keyword:`del` statement can also be used to remove
+slices from a list or clear the entire list (which we did earlier by assignment
+of an empty list to the slice).  For example::
+
+   >>> a = [-1, 1, 66.25, 333, 333, 1234.5]
+   >>> del a[0]
+   >>> a
+   [1, 66.25, 333, 333, 1234.5]
+   >>> del a[2:4]
+   >>> a
+   [1, 66.25, 1234.5]
+   >>> del a[:]
+   >>> a
+   []
+
+:keyword:`del` can also be used to delete entire variables::
+
+   >>> del a
+
+Referencing the name ``a`` hereafter is an error (at least until another value
+is assigned to it).  We'll find other uses for :keyword:`del` later.
+
+
+.. _tut-tuples:
+
+Tuples and Sequences
+====================
+
+We saw that lists and strings have many common properties, such as indexing and
+slicing operations.  They are two examples of *sequence* data types (see
+:ref:`typesseq`).  Since Python is an evolving language, other sequence data
+types may be added.  There is also another standard sequence data type: the
+*tuple*.
+
+A tuple consists of a number of values separated by commas, for instance::
+
+   >>> t = 12345, 54321, 'hello!'
+   >>> t[0]
+   12345
+   >>> t
+   (12345, 54321, 'hello!')
+   >>> # Tuples may be nested:
+   ... u = t, (1, 2, 3, 4, 5)
+   >>> u
+   ((12345, 54321, 'hello!'), (1, 2, 3, 4, 5))
+
+As you see, on output tuples are always enclosed in parentheses, so that nested
+tuples are interpreted correctly; they may be input with or without surrounding
+parentheses, although often parentheses are necessary anyway (if the tuple is
+part of a larger expression).
+
+Tuples have many uses.  For example: (x, y) coordinate pairs, employee records
+from a database, etc.  Tuples, like strings, are immutable: it is not possible
+to assign to the individual items of a tuple (you can simulate much of the same
+effect with slicing and concatenation, though).  It is also possible to create
+tuples which contain mutable objects, such as lists.
+
+A special problem is the construction of tuples containing 0 or 1 items: the
+syntax has some extra quirks to accommodate these.  Empty tuples are constructed
+by an empty pair of parentheses; a tuple with one item is constructed by
+following a value with a comma (it is not sufficient to enclose a single value
+in parentheses). Ugly, but effective.  For example::
+
+   >>> empty = ()
+   >>> singleton = 'hello',    # <-- note trailing comma
+   >>> len(empty)
+   0
+   >>> len(singleton)
+   1
+   >>> singleton
+   ('hello',)
+
+The statement ``t = 12345, 54321, 'hello!'`` is an example of *tuple packing*:
+the values ``12345``, ``54321`` and ``'hello!'`` are packed together in a tuple.
+The reverse operation is also possible::
+
+   >>> x, y, z = t
+
+This is called, appropriately enough, *sequence unpacking*. Sequence unpacking
+requires the list of variables on the left to have the same number of elements
+as the length of the sequence.  Note that multiple assignment is really just a
+combination of tuple packing and sequence unpacking!
+
+There is a small bit of asymmetry here:  packing multiple values always creates
+a tuple, and unpacking works for any sequence.
+
+.. % XXX Add a bit on the difference between tuples and lists.
+
+
+.. _tut-sets:
+
+Sets
+====
+
+Python also includes a data type for *sets*.  A set is an unordered collection
+with no duplicate elements.  Basic uses include membership testing and
+eliminating duplicate entries.  Set objects also support mathematical operations
+like union, intersection, difference, and symmetric difference.
+
+Here is a brief demonstration::
+
+   >>> basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']
+   >>> fruit = set(basket)               # create a set without duplicates
+   >>> fruit
+   set(['orange', 'pear', 'apple', 'banana'])
+   >>> 'orange' in fruit                 # fast membership testing
+   True
+   >>> 'crabgrass' in fruit
+   False
+
+   >>> # Demonstrate set operations on unique letters from two words
+   ...
+   >>> a = set('abracadabra')
+   >>> b = set('alacazam')
+   >>> a                                  # unique letters in a
+   set(['a', 'r', 'b', 'c', 'd'])
+   >>> a - b                              # letters in a but not in b
+   set(['r', 'd', 'b'])
+   >>> a | b                              # letters in either a or b
+   set(['a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'])
+   >>> a & b                              # letters in both a and b
+   set(['a', 'c'])
+   >>> a ^ b                              # letters in a or b but not both
+   set(['r', 'd', 'b', 'm', 'z', 'l'])
+
+
+.. _tut-dictionaries:
+
+Dictionaries
+============
+
+Another useful data type built into Python is the *dictionary* (see
+:ref:`typesmapping`). Dictionaries are sometimes found in other languages as
+"associative memories" or "associative arrays".  Unlike sequences, which are
+indexed by a range of numbers, dictionaries are indexed by *keys*, which can be
+any immutable type; strings and numbers can always be keys.  Tuples can be used
+as keys if they contain only strings, numbers, or tuples; if a tuple contains
+any mutable object either directly or indirectly, it cannot be used as a key.
+You can't use lists as keys, since lists can be modified in place using index
+assignments, slice assignments, or methods like :meth:`append` and
+:meth:`extend`.
+
+It is best to think of a dictionary as an unordered set of *key: value* pairs,
+with the requirement that the keys are unique (within one dictionary). A pair of
+braces creates an empty dictionary: ``{}``. Placing a comma-separated list of
+key:value pairs within the braces adds initial key:value pairs to the
+dictionary; this is also the way dictionaries are written on output.
+
+The main operations on a dictionary are storing a value with some key and
+extracting the value given the key.  It is also possible to delete a key:value
+pair with ``del``. If you store using a key that is already in use, the old
+value associated with that key is forgotten.  It is an error to extract a value
+using a non-existent key.
+
+The :meth:`keys` method of a dictionary object returns a list of all the keys
+used in the dictionary, in arbitrary order (if you want it sorted, just apply
+the :meth:`sort` method to the list of keys).  To check whether a single key is
+in the dictionary, either use the dictionary's :meth:`has_key` method or the
+:keyword:`in` keyword.
+
+Here is a small example using a dictionary::
+
+   >>> tel = {'jack': 4098, 'sape': 4139}
+   >>> tel['guido'] = 4127
+   >>> tel
+   {'sape': 4139, 'guido': 4127, 'jack': 4098}
+   >>> tel['jack']
+   4098
+   >>> del tel['sape']
+   >>> tel['irv'] = 4127
+   >>> tel
+   {'guido': 4127, 'irv': 4127, 'jack': 4098}
+   >>> tel.keys()
+   ['guido', 'irv', 'jack']
+   >>> tel.has_key('guido')
+   True
+   >>> 'guido' in tel
+   True
+
+The :func:`dict` constructor builds dictionaries directly from lists of
+key-value pairs stored as tuples.  When the pairs form a pattern, list
+comprehensions can compactly specify the key-value list. ::
+
+   >>> dict([('sape', 4139), ('guido', 4127), ('jack', 4098)])
+   {'sape': 4139, 'jack': 4098, 'guido': 4127}
+   >>> dict([(x, x**2) for x in (2, 4, 6)])     # use a list comprehension
+   {2: 4, 4: 16, 6: 36}
+
+Later in the tutorial, we will learn about Generator Expressions which are even
+better suited for the task of supplying key-values pairs to the :func:`dict`
+constructor.
+
+When the keys are simple strings, it is sometimes easier to specify pairs using
+keyword arguments::
+
+   >>> dict(sape=4139, guido=4127, jack=4098)
+   {'sape': 4139, 'jack': 4098, 'guido': 4127}
+
+
+.. _tut-loopidioms:
+
+Looping Techniques
+==================
+
+When looping through dictionaries, the key and corresponding value can be
+retrieved at the same time using the :meth:`iteritems` method. ::
+
+   >>> knights = {'gallahad': 'the pure', 'robin': 'the brave'}
+   >>> for k, v in knights.iteritems():
+   ...     print k, v
+   ...
+   gallahad the pure
+   robin the brave
+
+When looping through a sequence, the position index and corresponding value can
+be retrieved at the same time using the :func:`enumerate` function. ::
+
+   >>> for i, v in enumerate(['tic', 'tac', 'toe']):
+   ...     print i, v
+   ...
+   0 tic
+   1 tac
+   2 toe
+
+To loop over two or more sequences at the same time, the entries can be paired
+with the :func:`zip` function. ::
+
+   >>> questions = ['name', 'quest', 'favorite color']
+   >>> answers = ['lancelot', 'the holy grail', 'blue']
+   >>> for q, a in zip(questions, answers):
+   ...     print 'What is your %s?  It is %s.' % (q, a)
+   ...	
+   What is your name?  It is lancelot.
+   What is your quest?  It is the holy grail.
+   What is your favorite color?  It is blue.
+
+To loop over a sequence in reverse, first specify the sequence in a forward
+direction and then call the :func:`reversed` function. ::
+
+   >>> for i in reversed(range(1,10,2)):
+   ...     print i
+   ...
+   9
+   7
+   5
+   3
+   1
+
+To loop over a sequence in sorted order, use the :func:`sorted` function which
+returns a new sorted list while leaving the source unaltered. ::
+
+   >>> basket = ['apple', 'orange', 'apple', 'pear', 'orange', 'banana']
+   >>> for f in sorted(set(basket)):
+   ...     print f
+   ... 	
+   apple
+   banana
+   orange
+   pear
+
+
+.. _tut-conditions:
+
+More on Conditions
+==================
+
+The conditions used in ``while`` and ``if`` statements can contain any
+operators, not just comparisons.
+
+The comparison operators ``in`` and ``not in`` check whether a value occurs
+(does not occur) in a sequence.  The operators ``is`` and ``is not`` compare
+whether two objects are really the same object; this only matters for mutable
+objects like lists.  All comparison operators have the same priority, which is
+lower than that of all numerical operators.
+
+Comparisons can be chained.  For example, ``a < b == c`` tests whether ``a`` is
+less than ``b`` and moreover ``b`` equals ``c``.
+
+Comparisons may be combined using the Boolean operators ``and`` and ``or``, and
+the outcome of a comparison (or of any other Boolean expression) may be negated
+with ``not``.  These have lower priorities than comparison operators; between
+them, ``not`` has the highest priority and ``or`` the lowest, so that ``A and
+not B or C`` is equivalent to ``(A and (not B)) or C``. As always, parentheses
+can be used to express the desired composition.
+
+The Boolean operators ``and`` and ``or`` are so-called *short-circuit*
+operators: their arguments are evaluated from left to right, and evaluation
+stops as soon as the outcome is determined.  For example, if ``A`` and ``C`` are
+true but ``B`` is false, ``A and B and C`` does not evaluate the expression
+``C``.  When used as a general value and not as a Boolean, the return value of a
+short-circuit operator is the last evaluated argument.
+
+It is possible to assign the result of a comparison or other Boolean expression
+to a variable.  For example, ::
+
+   >>> string1, string2, string3 = '', 'Trondheim', 'Hammer Dance'
+   >>> non_null = string1 or string2 or string3
+   >>> non_null
+   'Trondheim'
+
+Note that in Python, unlike C, assignment cannot occur inside expressions. C
+programmers may grumble about this, but it avoids a common class of problems
+encountered in C programs: typing ``=`` in an expression when ``==`` was
+intended.
+
+
+.. _tut-comparing:
+
+Comparing Sequences and Other Types
+===================================
+
+Sequence objects may be compared to other objects with the same sequence type.
+The comparison uses *lexicographical* ordering: first the first two items are
+compared, and if they differ this determines the outcome of the comparison; if
+they are equal, the next two items are compared, and so on, until either
+sequence is exhausted. If two items to be compared are themselves sequences of
+the same type, the lexicographical comparison is carried out recursively.  If
+all items of two sequences compare equal, the sequences are considered equal.
+If one sequence is an initial sub-sequence of the other, the shorter sequence is
+the smaller (lesser) one.  Lexicographical ordering for strings uses the ASCII
+ordering for individual characters.  Some examples of comparisons between
+sequences of the same type::
+
+   (1, 2, 3)              < (1, 2, 4)
+   [1, 2, 3]              < [1, 2, 4]
+   'ABC' < 'C' < 'Pascal' < 'Python'
+   (1, 2, 3, 4)           < (1, 2, 4)
+   (1, 2)                 < (1, 2, -1)
+   (1, 2, 3)             == (1.0, 2.0, 3.0)
+   (1, 2, ('aa', 'ab'))   < (1, 2, ('abc', 'a'), 4)
+
+Note that comparing objects of different types is legal.  The outcome is
+deterministic but arbitrary: the types are ordered by their name. Thus, a list
+is always smaller than a string, a string is always smaller than a tuple, etc.
+[#]_ Mixed numeric types are compared according to their numeric value, so 0
+equals 0.0, etc.
+
+
+.. rubric:: Footnotes
+
+.. [#] The rules for comparing objects of different types should not be relied upon;
+   they may change in a future version of the language.
+
diff --git a/Doc/tutorial/errors.rst b/Doc/tutorial/errors.rst
new file mode 100644
index 0000000..99af9c7
--- /dev/null
+++ b/Doc/tutorial/errors.rst
@@ -0,0 +1,418 @@
+.. _tut-errors:
+
+*********************
+Errors and Exceptions
+*********************
+
+Until now error messages haven't been more than mentioned, but if you have tried
+out the examples you have probably seen some.  There are (at least) two
+distinguishable kinds of errors: *syntax errors* and *exceptions*.
+
+
+.. _tut-syntaxerrors:
+
+Syntax Errors
+=============
+
+Syntax errors, also known as parsing errors, are perhaps the most common kind of
+complaint you get while you are still learning Python::
+
+   >>> while True print 'Hello world'
+     File "<stdin>", line 1, in ?
+       while True print 'Hello world'
+                      ^
+   SyntaxError: invalid syntax
+
+The parser repeats the offending line and displays a little 'arrow' pointing at
+the earliest point in the line where the error was detected.  The error is
+caused by (or at least detected at) the token *preceding* the arrow: in the
+example, the error is detected at the keyword :keyword:`print`, since a colon
+(``':'``) is missing before it.  File name and line number are printed so you
+know where to look in case the input came from a script.
+
+
+.. _tut-exceptions:
+
+Exceptions
+==========
+
+Even if a statement or expression is syntactically correct, it may cause an
+error when an attempt is made to execute it. Errors detected during execution
+are called *exceptions* and are not unconditionally fatal: you will soon learn
+how to handle them in Python programs.  Most exceptions are not handled by
+programs, however, and result in error messages as shown here::
+
+   >>> 10 * (1/0)
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   ZeroDivisionError: integer division or modulo by zero
+   >>> 4 + spam*3
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   NameError: name 'spam' is not defined
+   >>> '2' + 2
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   TypeError: cannot concatenate 'str' and 'int' objects
+
+The last line of the error message indicates what happened. Exceptions come in
+different types, and the type is printed as part of the message: the types in
+the example are :exc:`ZeroDivisionError`, :exc:`NameError` and :exc:`TypeError`.
+The string printed as the exception type is the name of the built-in exception
+that occurred.  This is true for all built-in exceptions, but need not be true
+for user-defined exceptions (although it is a useful convention). Standard
+exception names are built-in identifiers (not reserved keywords).
+
+The rest of the line provides detail based on the type of exception and what
+caused it.
+
+The preceding part of the error message shows the context where the exception
+happened, in the form of a stack traceback. In general it contains a stack
+traceback listing source lines; however, it will not display lines read from
+standard input.
+
+:ref:`bltin-exceptions` lists the built-in exceptions and their meanings.
+
+
+.. _tut-handling:
+
+Handling Exceptions
+===================
+
+It is possible to write programs that handle selected exceptions. Look at the
+following example, which asks the user for input until a valid integer has been
+entered, but allows the user to interrupt the program (using :kbd:`Control-C` or
+whatever the operating system supports); note that a user-generated interruption
+is signalled by raising the :exc:`KeyboardInterrupt` exception. ::
+
+   >>> def raw_input(prompt):
+   ...     import sys
+   ...     sys.stdout.write(prompt)
+   ...     sys.stdout.flush()
+   ...     return sys.stdin.readline()
+   ... 
+   >>> while True:
+   ...     try:
+   ...         x = int(raw_input("Please enter a number: "))
+   ...         break
+   ...     except ValueError:
+   ...         print "Oops!  That was no valid number.  Try again..."
+   ...     
+
+The :keyword:`try` statement works as follows.
+
+* First, the *try clause* (the statement(s) between the :keyword:`try` and
+  :keyword:`except` keywords) is executed.
+
+* If no exception occurs, the *except clause* is skipped and execution of the
+  :keyword:`try` statement is finished.
+
+* If an exception occurs during execution of the try clause, the rest of the
+  clause is skipped.  Then if its type matches the exception named after the
+  :keyword:`except` keyword, the except clause is executed, and then execution
+  continues after the :keyword:`try` statement.
+
+* If an exception occurs which does not match the exception named in the except
+  clause, it is passed on to outer :keyword:`try` statements; if no handler is
+  found, it is an *unhandled exception* and execution stops with a message as
+  shown above.
+
+A :keyword:`try` statement may have more than one except clause, to specify
+handlers for different exceptions.  At most one handler will be executed.
+Handlers only handle exceptions that occur in the corresponding try clause, not
+in other handlers of the same :keyword:`try` statement.  An except clause may
+name multiple exceptions as a parenthesized tuple, for example::
+
+   ... except (RuntimeError, TypeError, NameError):
+   ...     pass
+
+The last except clause may omit the exception name(s), to serve as a wildcard.
+Use this with extreme caution, since it is easy to mask a real programming error
+in this way!  It can also be used to print an error message and then re-raise
+the exception (allowing a caller to handle the exception as well)::
+
+   import sys
+
+   try:
+       f = open('myfile.txt')
+       s = f.readline()
+       i = int(s.strip())
+   except IOError as e:
+       (errno, strerror) = e
+       print "I/O error(%s): %s" % (e.errno, e.strerror)
+   except ValueError:
+       print "Could not convert data to an integer."
+   except:
+       print "Unexpected error:", sys.exc_info()[0]
+       raise
+
+The :keyword:`try` ... :keyword:`except` statement has an optional *else
+clause*, which, when present, must follow all except clauses.  It is useful for
+code that must be executed if the try clause does not raise an exception.  For
+example::
+
+   for arg in sys.argv[1:]:
+       try:
+           f = open(arg, 'r')
+       except IOError:
+           print 'cannot open', arg
+       else:
+           print arg, 'has', len(f.readlines()), 'lines'
+           f.close()
+
+The use of the :keyword:`else` clause is better than adding additional code to
+the :keyword:`try` clause because it avoids accidentally catching an exception
+that wasn't raised by the code being protected by the :keyword:`try` ...
+:keyword:`except` statement.
+
+When an exception occurs, it may have an associated value, also known as the
+exception's *argument*. The presence and type of the argument depend on the
+exception type.
+
+The except clause may specify a variable after the exception name (or tuple).
+The variable is bound to an exception instance with the arguments stored in
+``instance.args``.  For convenience, the exception instance defines
+:meth:`__getitem__` and :meth:`__str__` so the arguments can be accessed or
+printed directly without having to reference ``.args``.
+
+But use of ``.args`` is discouraged.  Instead, the preferred use is to pass a
+single argument to an exception (which can be a tuple if multiple arguments are
+needed) and have it bound to the ``message`` attribute.  One may also
+instantiate an exception first before raising it and add any attributes to it as
+desired. ::
+
+   >>> try:
+   ...    raise Exception('spam', 'eggs')
+   ... except Exception as inst:
+   ...    print type(inst)     # the exception instance
+   ...    print inst.args      # arguments stored in .args
+   ...    print inst           # __str__ allows args to printed directly
+   ...    x, y = inst          # __getitem__ allows args to be unpacked directly
+   ...    print 'x =', x
+   ...    print 'y =', y
+   ...
+   <type 'Exception'>
+   ('spam', 'eggs')
+   ('spam', 'eggs')
+   x = spam
+   y = eggs
+
+If an exception has an argument, it is printed as the last part ('detail') of
+the message for unhandled exceptions.
+
+Exception handlers don't just handle exceptions if they occur immediately in the
+try clause, but also if they occur inside functions that are called (even
+indirectly) in the try clause. For example::
+
+   >>> def this_fails():
+   ...     x = 1/0
+   ... 
+   >>> try:
+   ...     this_fails()
+   ... except ZeroDivisionError as detail:
+   ...     print 'Handling run-time error:', detail
+   ... 
+   Handling run-time error: integer division or modulo by zero
+
+
+.. _tut-raising:
+
+Raising Exceptions
+==================
+
+The :keyword:`raise` statement allows the programmer to force a specified
+exception to occur. For example::
+
+   >>> raise NameError, 'HiThere'
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   NameError: HiThere
+
+The first argument to :keyword:`raise` names the exception to be raised.  The
+optional second argument specifies the exception's argument.  Alternatively, the
+above could be written as ``raise NameError('HiThere')``.  Either form works
+fine, but there seems to be a growing stylistic preference for the latter.
+
+If you need to determine whether an exception was raised but don't intend to
+handle it, a simpler form of the :keyword:`raise` statement allows you to
+re-raise the exception::
+
+   >>> try:
+   ...     raise NameError, 'HiThere'
+   ... except NameError:
+   ...     print 'An exception flew by!'
+   ...     raise
+   ...
+   An exception flew by!
+   Traceback (most recent call last):
+     File "<stdin>", line 2, in ?
+   NameError: HiThere
+
+
+.. _tut-userexceptions:
+
+User-defined Exceptions
+=======================
+
+Programs may name their own exceptions by creating a new exception class.
+Exceptions should typically be derived from the :exc:`Exception` class, either
+directly or indirectly.  For example::
+
+   >>> class MyError(Exception):
+   ...     def __init__(self, value):
+   ...         self.value = value
+   ...     def __str__(self):
+   ...         return repr(self.value)
+   ... 
+   >>> try:
+   ...     raise MyError(2*2)
+   ... except MyError as e:
+   ...     print 'My exception occurred, value:', e.value
+   ... 
+   My exception occurred, value: 4
+   >>> raise MyError, 'oops!'
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   __main__.MyError: 'oops!'
+
+In this example, the default :meth:`__init__` of :class:`Exception` has been
+overridden.  The new behavior simply creates the *value* attribute.  This
+replaces the default behavior of creating the *args* attribute.
+
+Exception classes can be defined which do anything any other class can do, but
+are usually kept simple, often only offering a number of attributes that allow
+information about the error to be extracted by handlers for the exception.  When
+creating a module that can raise several distinct errors, a common practice is
+to create a base class for exceptions defined by that module, and subclass that
+to create specific exception classes for different error conditions::
+
+   class Error(Exception):
+       """Base class for exceptions in this module."""
+       pass
+
+   class InputError(Error):
+       """Exception raised for errors in the input.
+
+       Attributes:
+           expression -- input expression in which the error occurred
+           message -- explanation of the error
+       """
+
+       def __init__(self, expression, message):
+           self.expression = expression
+           self.message = message
+
+   class TransitionError(Error):
+       """Raised when an operation attempts a state transition that's not
+       allowed.
+
+       Attributes:
+           previous -- state at beginning of transition
+           next -- attempted new state
+           message -- explanation of why the specific transition is not allowed
+       """
+
+       def __init__(self, previous, next, message):
+           self.previous = previous
+           self.next = next
+           self.message = message
+
+Most exceptions are defined with names that end in "Error," similar to the
+naming of the standard exceptions.
+
+Many standard modules define their own exceptions to report errors that may
+occur in functions they define.  More information on classes is presented in
+chapter :ref:`tut-classes`.
+
+
+.. _tut-cleanup:
+
+Defining Clean-up Actions
+=========================
+
+The :keyword:`try` statement has another optional clause which is intended to
+define clean-up actions that must be executed under all circumstances.  For
+example::
+
+   >>> try:
+   ...     raise KeyboardInterrupt
+   ... finally:
+   ...     print 'Goodbye, world!'
+   ... 
+   Goodbye, world!
+   Traceback (most recent call last):
+     File "<stdin>", line 2, in ?
+   KeyboardInterrupt
+
+A *finally clause* is always executed before leaving the :keyword:`try`
+statement, whether an exception has occurred or not. When an exception has
+occurred in the :keyword:`try` clause and has not been handled by an
+:keyword:`except` clause (or it has occurred in a :keyword:`except` or
+:keyword:`else` clause), it is re-raised after the :keyword:`finally` clause has
+been executed.  The :keyword:`finally` clause is also executed "on the way out"
+when any other clause of the :keyword:`try` statement is left via a
+:keyword:`break`, :keyword:`continue` or :keyword:`return` statement.  A more
+complicated example (having :keyword:`except` and :keyword:`finally` clauses in
+the same :keyword:`try` statement works as of Python 2.5)::
+
+   >>> def divide(x, y):
+   ...     try:
+   ...         result = x / y
+   ...     except ZeroDivisionError:
+   ...         print "division by zero!"
+   ...     else:
+   ...         print "result is", result
+   ...     finally:
+   ...         print "executing finally clause"
+   ...
+   >>> divide(2, 1)
+   result is 2
+   executing finally clause
+   >>> divide(2, 0)
+   division by zero!
+   executing finally clause
+   >>> divide("2", "1")
+   executing finally clause
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+     File "<stdin>", line 3, in divide
+   TypeError: unsupported operand type(s) for /: 'str' and 'str'
+
+As you can see, the :keyword:`finally` clause is executed in any event.  The
+:exc:`TypeError` raised by dividing two strings is not handled by the
+:keyword:`except` clause and therefore re-raised after the :keyword:`finally`
+clauses has been executed.
+
+In real world applications, the :keyword:`finally` clause is useful for
+releasing external resources (such as files or network connections), regardless
+of whether the use of the resource was successful.
+
+
+.. _tut-cleanup-with:
+
+Predefined Clean-up Actions
+===========================
+
+Some objects define standard clean-up actions to be undertaken when the object
+is no longer needed, regardless of whether or not the operation using the object
+succeeded or failed. Look at the following example, which tries to open a file
+and print its contents to the screen. ::
+
+   for line in open("myfile.txt"):
+       print line
+
+The problem with this code is that it leaves the file open for an indeterminate
+amount of time after the code has finished executing. This is not an issue in
+simple scripts, but can be a problem for larger applications. The
+:keyword:`with` statement allows objects like files to be used in a way that
+ensures they are always cleaned up promptly and correctly. ::
+
+   with open("myfile.txt") as f:
+       for line in f:
+           print line
+
+After the statement is executed, the file *f* is always closed, even if a
+problem was encountered while processing the lines. Other objects which provide
+predefined clean-up actions will indicate this in their documentation.
+
+
diff --git a/Doc/tutorial/floatingpoint.rst b/Doc/tutorial/floatingpoint.rst
new file mode 100644
index 0000000..cbf7008
--- /dev/null
+++ b/Doc/tutorial/floatingpoint.rst
@@ -0,0 +1,220 @@
+.. _tut-fp-issues:
+
+**************************************************
+Floating Point Arithmetic:  Issues and Limitations
+**************************************************
+
+.. sectionauthor:: Tim Peters <tim_one@users.sourceforge.net>
+
+
+Floating-point numbers are represented in computer hardware as base 2 (binary)
+fractions.  For example, the decimal fraction ::
+
+   0.125
+
+has value 1/10 + 2/100 + 5/1000, and in the same way the binary fraction ::
+
+   0.001
+
+has value 0/2 + 0/4 + 1/8.  These two fractions have identical values, the only
+real difference being that the first is written in base 10 fractional notation,
+and the second in base 2.
+
+Unfortunately, most decimal fractions cannot be represented exactly as binary
+fractions.  A consequence is that, in general, the decimal floating-point
+numbers you enter are only approximated by the binary floating-point numbers
+actually stored in the machine.
+
+The problem is easier to understand at first in base 10.  Consider the fraction
+1/3.  You can approximate that as a base 10 fraction::
+
+   0.3
+
+or, better, ::
+
+   0.33
+
+or, better, ::
+
+   0.333
+
+and so on.  No matter how many digits you're willing to write down, the result
+will never be exactly 1/3, but will be an increasingly better approximation of
+1/3.
+
+In the same way, no matter how many base 2 digits you're willing to use, the
+decimal value 0.1 cannot be represented exactly as a base 2 fraction.  In base
+2, 1/10 is the infinitely repeating fraction ::
+
+   0.0001100110011001100110011001100110011001100110011...
+
+Stop at any finite number of bits, and you get an approximation.  This is why
+you see things like::
+
+   >>> 0.1
+   0.10000000000000001
+
+On most machines today, that is what you'll see if you enter 0.1 at a Python
+prompt.  You may not, though, because the number of bits used by the hardware to
+store floating-point values can vary across machines, and Python only prints a
+decimal approximation to the true decimal value of the binary approximation
+stored by the machine.  On most machines, if Python were to print the true
+decimal value of the binary approximation stored for 0.1, it would have to
+display ::
+
+   >>> 0.1
+   0.1000000000000000055511151231257827021181583404541015625
+
+instead!  The Python prompt uses the builtin :func:`repr` function to obtain a
+string version of everything it displays.  For floats, ``repr(float)`` rounds
+the true decimal value to 17 significant digits, giving ::
+
+   0.10000000000000001
+
+``repr(float)`` produces 17 significant digits because it turns out that's
+enough (on most machines) so that ``eval(repr(x)) == x`` exactly for all finite
+floats *x*, but rounding to 16 digits is not enough to make that true.
+
+Note that this is in the very nature of binary floating-point: this is not a bug
+in Python, and it is not a bug in your code either.  You'll see the same kind of
+thing in all languages that support your hardware's floating-point arithmetic
+(although some languages may not *display* the difference by default, or in all
+output modes).
+
+Python's builtin :func:`str` function produces only 12 significant digits, and
+you may wish to use that instead.  It's unusual for ``eval(str(x))`` to
+reproduce *x*, but the output may be more pleasant to look at::
+
+   >>> print str(0.1)
+   0.1
+
+It's important to realize that this is, in a real sense, an illusion: the value
+in the machine is not exactly 1/10, you're simply rounding the *display* of the
+true machine value.
+
+Other surprises follow from this one.  For example, after seeing ::
+
+   >>> 0.1
+   0.10000000000000001
+
+you may be tempted to use the :func:`round` function to chop it back to the
+single digit you expect.  But that makes no difference::
+
+   >>> round(0.1, 1)
+   0.10000000000000001
+
+The problem is that the binary floating-point value stored for "0.1" was already
+the best possible binary approximation to 1/10, so trying to round it again
+can't make it better:  it was already as good as it gets.
+
+Another consequence is that since 0.1 is not exactly 1/10, summing ten values of
+0.1 may not yield exactly 1.0, either::
+
+   >>> sum = 0.0
+   >>> for i in range(10):
+   ...     sum += 0.1
+   ...
+   >>> sum
+   0.99999999999999989
+
+Binary floating-point arithmetic holds many surprises like this.  The problem
+with "0.1" is explained in precise detail below, in the "Representation Error"
+section.  See `The Perils of Floating Point <http://www.lahey.com/float.htm>`_
+for a more complete account of other common surprises.
+
+As that says near the end, "there are no easy answers."  Still, don't be unduly
+wary of floating-point!  The errors in Python float operations are inherited
+from the floating-point hardware, and on most machines are on the order of no
+more than 1 part in 2\*\*53 per operation.  That's more than adequate for most
+tasks, but you do need to keep in mind that it's not decimal arithmetic, and
+that every float operation can suffer a new rounding error.
+
+While pathological cases do exist, for most casual use of floating-point
+arithmetic you'll see the result you expect in the end if you simply round the
+display of your final results to the number of decimal digits you expect.
+:func:`str` usually suffices, and for finer control see the discussion of
+Python's ``%`` format operator: the ``%g``, ``%f`` and ``%e`` format codes
+supply flexible and easy ways to round float results for display.
+
+
+.. _tut-fp-error:
+
+Representation Error
+====================
+
+This section explains the "0.1" example in detail, and shows how you can perform
+an exact analysis of cases like this yourself.  Basic familiarity with binary
+floating-point representation is assumed.
+
+:dfn:`Representation error` refers to the fact that some (most, actually)
+decimal fractions cannot be represented exactly as binary (base 2) fractions.
+This is the chief reason why Python (or Perl, C, C++, Java, Fortran, and many
+others) often won't display the exact decimal number you expect::
+
+   >>> 0.1
+   0.10000000000000001
+
+Why is that?  1/10 is not exactly representable as a binary fraction. Almost all
+machines today (November 2000) use IEEE-754 floating point arithmetic, and
+almost all platforms map Python floats to IEEE-754 "double precision".  754
+doubles contain 53 bits of precision, so on input the computer strives to
+convert 0.1 to the closest fraction it can of the form *J*/2\*\**N* where *J* is
+an integer containing exactly 53 bits.  Rewriting ::
+
+   1 / 10 ~= J / (2**N)
+
+as ::
+
+   J ~= 2**N / 10
+
+and recalling that *J* has exactly 53 bits (is ``>= 2**52`` but ``< 2**53``),
+the best value for *N* is 56::
+
+   >>> 2**52
+   4503599627370496L
+   >>> 2**53
+   9007199254740992L
+   >>> 2**56/10
+   7205759403792793L
+
+That is, 56 is the only value for *N* that leaves *J* with exactly 53 bits.  The
+best possible value for *J* is then that quotient rounded::
+
+   >>> q, r = divmod(2**56, 10)
+   >>> r
+   6L
+
+Since the remainder is more than half of 10, the best approximation is obtained
+by rounding up::
+
+   >>> q+1
+   7205759403792794L
+
+Therefore the best possible approximation to 1/10 in 754 double precision is
+that over 2\*\*56, or ::
+
+   7205759403792794 / 72057594037927936
+
+Note that since we rounded up, this is actually a little bit larger than 1/10;
+if we had not rounded up, the quotient would have been a little bit smaller than
+1/10.  But in no case can it be *exactly* 1/10!
+
+So the computer never "sees" 1/10:  what it sees is the exact fraction given
+above, the best 754 double approximation it can get::
+
+   >>> .1 * 2**56
+   7205759403792794.0
+
+If we multiply that fraction by 10\*\*30, we can see the (truncated) value of
+its 30 most significant decimal digits::
+
+   >>> 7205759403792794 * 10**30 / 2**56
+   100000000000000005551115123125L
+
+meaning that the exact number stored in the computer is approximately equal to
+the decimal value 0.100000000000000005551115123125.  Rounding that to 17
+significant digits gives the 0.10000000000000001 that Python displays (well,
+will display on any 754-conforming platform that does best-possible input and
+output conversions in its C library --- yours may not!).
+
+
diff --git a/Doc/tutorial/glossary.rst b/Doc/tutorial/glossary.rst
new file mode 100644
index 0000000..c05d68d
--- /dev/null
+++ b/Doc/tutorial/glossary.rst
@@ -0,0 +1,329 @@
+
+.. _tut-glossary:
+
+********
+Glossary
+********
+
+.. % %% keep the entries sorted and include at least one \index{} item for each
+.. % %% cross-references are marked with \emph{entry}
+
+``>>>``
+   The typical Python prompt of the interactive shell.  Often seen for code
+   examples that can be tried right away in the interpreter.
+
+   .. index:: single: ...
+
+``...``
+   The typical Python prompt of the interactive shell when entering code for an
+   indented code block.
+
+   .. index:: single: BDFL
+
+BDFL
+   Benevolent Dictator For Life, a.k.a. `Guido van Rossum
+   <http://www.python.org/~guido/>`_, Python's creator.
+
+   .. index:: single: byte code
+
+byte code
+   The internal representation of a Python program in the interpreter. The byte
+   code is also cached in ``.pyc`` and ``.pyo`` files so that executing the same
+   file is faster the second time (recompilation from source to byte code can be
+   avoided).  This "intermediate language" is said to run on a "virtual machine"
+   that calls the subroutines corresponding to each bytecode.
+
+   .. index:: single: classic class
+
+classic class
+   Any class which does not inherit from :class:`object`.  See *new-style class*.
+
+   .. index:: single: complex number
+
+complex number
+   An extension of the familiar real number system in which all numbers are
+   expressed as a sum of a real part and an imaginary part.  Imaginary numbers are
+   real multiples of the imaginary unit (the square root of ``-1``), often written
+   ``i`` in mathematics or ``j`` in engineering. Python has builtin support for
+   complex numbers, which are written with this latter notation; the imaginary part
+   is written with a ``j`` suffix, e.g., ``3+1j``.  To get access to complex
+   equivalents of the :mod:`math` module, use :mod:`cmath`.  Use of complex numbers
+   is a fairly advanced mathematical feature.  If you're not aware of a need for
+   them, it's almost certain you can safely ignore them.
+
+   .. index:: single: descriptor
+
+descriptor
+   Any *new-style* object that defines the methods :meth:`__get__`,
+   :meth:`__set__`, or :meth:`__delete__`. When a class attribute is a descriptor,
+   its special binding behavior is triggered upon attribute lookup.  Normally,
+   writing *a.b* looks up the object *b* in the class dictionary for *a*, but if
+   *b* is a descriptor, the defined method gets called. Understanding descriptors
+   is a key to a deep understanding of Python because they are the basis for many
+   features including functions, methods, properties, class methods, static
+   methods, and reference to super classes.
+
+   .. index:: single: dictionary
+
+dictionary
+   An associative array, where arbitrary keys are mapped to values.  The use of
+   :class:`dict` much resembles that for :class:`list`, but the keys can be any
+   object with a :meth:`__hash__` function, not just integers starting from zero.
+   Called a hash in Perl.
+
+   .. index:: single: duck-typing
+
+duck-typing
+   Pythonic programming style that determines an object's type by inspection of its
+   method or attribute signature rather than by explicit relationship to some type
+   object ("If it looks like a duck and quacks like a duck, it must be a duck.")
+   By emphasizing interfaces rather than specific types, well-designed code
+   improves its flexibility by allowing polymorphic substitution.  Duck-typing
+   avoids tests using :func:`type` or :func:`isinstance`. Instead, it typically
+   employs :func:`hasattr` tests or *EAFP* programming.
+
+   .. index:: single: EAFP
+
+EAFP
+   Easier to ask for forgiveness than permission.  This common Python coding style
+   assumes the existence of valid keys or attributes and catches exceptions if the
+   assumption proves false.  This clean and fast style is characterized by the
+   presence of many :keyword:`try` and :keyword:`except` statements.  The technique
+   contrasts with the *LBYL* style that is common in many other languages such as
+   C.
+
+   .. index:: single: __future__
+
+__future__
+   A pseudo module which programmers can use to enable new language features which
+   are not compatible with the current interpreter. To enable ``new_feature`` ::
+
+      from __future__ import new_feature
+
+   By importing the :mod:`__future__` module and evaluating its variables, you
+   can see when a new feature was first added to the language and when it will
+   become the default::
+
+      >>> import __future__
+      >>> __future__.division
+      _Feature((2, 2, 0, 'alpha', 2), (3, 0, 0, 'alpha', 0), 8192)
+
+   .. index:: single: generator
+
+generator
+   A function that returns an iterator.  It looks like a normal function except
+   that values are returned to the caller using a :keyword:`yield` statement
+   instead of a :keyword:`return` statement.  Generator functions often contain one
+   or more :keyword:`for` or :keyword:`while` loops that :keyword:`yield` elements
+   back to the caller.  The function execution is stopped at the :keyword:`yield`
+   keyword (returning the result) and is resumed there when the next element is
+   requested by calling the :meth:`__next__` method of the returned iterator.
+
+   .. index:: single: generator expression
+
+generator expression
+   An expression that returns a generator.  It looks like a normal expression
+   followed by a :keyword:`for` expression defining a loop variable, range, and an
+   optional :keyword:`if` expression.  The combined expression generates values for
+   an enclosing function::
+
+      >>> sum(i*i for i in range(10))         # sum of squares 0, 1, 4, ... 81
+      285
+
+   .. index:: single: GIL
+
+GIL
+   See *global interpreter lock*.
+
+   .. index:: single: global interpreter lock
+
+global interpreter lock
+   The lock used by Python threads to assure that only one thread can be run at
+   a time.  This simplifies Python by assuring that no two processes can access
+   the same memory at the same time.  Locking the entire interpreter makes it
+   easier for the interpreter to be multi-threaded, at the expense of some
+   parallelism on multi-processor machines.  Efforts have been made in the past
+   to create a "free-threaded" interpreter (one which locks shared data at a
+   much finer granularity), but performance suffered in the common
+   single-processor case.
+
+   .. index:: single: IDLE
+
+IDLE
+   An Integrated Development Environment for Python.  IDLE is a basic editor and
+   interpreter environment that ships with the standard distribution of Python.
+   Good for beginners, it also serves as clear example code for those wanting to
+   implement a moderately sophisticated, multi-platform GUI application.
+
+   .. index:: single: immutable
+
+immutable
+   An object with fixed value.  Immutable objects are numbers, strings or tuples
+   (and more).  Such an object cannot be altered.  A new object has to be created
+   if a different value has to be stored.  They play an important role in places
+   where a constant hash value is needed, for example as a key in a dictionary.
+
+   .. index:: single: integer division
+
+integer division
+   Mathematical division including any remainder.  The result will always be a
+   float.  For example, the expression ``11/4`` evaluates to ``2.75``. Integer
+   division can be forced by using the ``//`` operator instead of the ``/``
+   operator.
+
+   .. index:: single: interactive
+
+interactive
+   Python has an interactive interpreter which means that you can try out things
+   and immediately see their results.  Just launch ``python`` with no arguments
+   (possibly by selecting it from your computer's main menu). It is a very powerful
+   way to test out new ideas or inspect modules and packages (remember
+   ``help(x)``).
+
+   .. index:: single: interpreted
+
+interpreted
+   Python is an interpreted language, as opposed to a compiled one.  This means
+   that the source files can be run directly without first creating an executable
+   which is then run.  Interpreted languages typically have a shorter
+   development/debug cycle than compiled ones, though their programs generally also
+   run more slowly.  See also *interactive*.
+
+   .. index:: single: iterable
+
+iterable
+   A container object capable of returning its members one at a time. Examples of
+   iterables include all sequence types (such as :class:`list`, :class:`str`, and
+   :class:`tuple`) and some non-sequence types like :class:`dict` and :class:`file`
+   and objects of any classes you define with an :meth:`__iter__` or
+   :meth:`__getitem__` method.  Iterables can be used in a :keyword:`for` loop and
+   in many other places where a sequence is needed (:func:`zip`, :func:`map`, ...).
+   When an iterable object is passed as an argument to the builtin function
+   :func:`iter`, it returns an iterator for the object.  This iterator is good for
+   one pass over the set of values.  When using iterables, it is usually not
+   necessary to call :func:`iter` or deal with iterator objects yourself.  The
+   ``for`` statement does that automatically for you, creating a temporary unnamed
+   variable to hold the iterator for the duration of the loop.  See also
+   *iterator*, *sequence*, and *generator*.
+
+   .. index:: single: iterator
+
+iterator
+   An object representing a stream of data.  Repeated calls to the iterator's
+   :meth:`__next__` method return successive items in the stream.  When no more
+   data is available a :exc:`StopIteration` exception is raised instead.  At this
+   point, the iterator object is exhausted and any further calls to its
+   :meth:`__next__` method just raise :exc:`StopIteration` again.  Iterators are
+   required to have an :meth:`__iter__` method that returns the iterator object
+   itself so every iterator is also iterable and may be used in most places where
+   other iterables are accepted.  One notable exception is code that attempts
+   multiple iteration passes.  A container object (such as a :class:`list`)
+   produces a fresh new iterator each time you pass it to the :func:`iter` function
+   or use it in a :keyword:`for` loop.  Attempting this with an iterator will just
+   return the same exhausted iterator object used in the previous iteration pass,
+   making it appear like an empty container.
+
+   .. index:: single: LBYL
+
+LBYL
+   Look before you leap.  This coding style explicitly tests for pre-conditions
+   before making calls or lookups.  This style contrasts with the *EAFP* approach
+   and is characterized by the presence of many :keyword:`if` statements.
+
+   .. index:: single: list comprehension
+
+list comprehension
+   A compact way to process all or a subset of elements in a sequence and return a
+   list with the results.  ``result = ["0x%02x" % x for x in range(256) if x % 2 ==
+   0]`` generates a list of strings containing hex numbers (0x..) that are even and
+   in the range from 0 to 255. The :keyword:`if` clause is optional.  If omitted,
+   all elements in ``range(256)`` are processed.
+
+   .. index:: single: mapping
+
+mapping
+   A container object (such as :class:`dict`) that supports arbitrary key lookups
+   using the special method :meth:`__getitem__`.
+
+   .. index:: single: metaclass
+
+metaclass
+   The class of a class.  Class definitions create a class name, a class
+   dictionary, and a list of base classes.  The metaclass is responsible for taking
+   those three arguments and creating the class.  Most object oriented programming
+   languages provide a default implementation.  What makes Python special is that
+   it is possible to create custom metaclasses.  Most users never need this tool,
+   but when the need arises, metaclasses can provide powerful, elegant solutions.
+   They have been used for logging attribute access, adding thread-safety, tracking
+   object creation, implementing singletons, and many other tasks.
+
+   .. index:: single: mutable
+
+mutable
+   Mutable objects can change their value but keep their :func:`id`. See also
+   *immutable*.
+
+   .. index:: single: namespace
+
+namespace
+   The place where a variable is stored.  Namespaces are implemented as
+   dictionaries.  There are the local, global and builtin namespaces as well as
+   nested namespaces in objects (in methods).  Namespaces support modularity by
+   preventing naming conflicts.  For instance, the functions
+   :func:`__builtin__.open` and :func:`os.open` are distinguished by their
+   namespaces.  Namespaces also aid readability and maintainability by making it
+   clear which module implements a function.  For instance, writing
+   :func:`random.seed` or :func:`itertools.izip` makes it clear that those
+   functions are implemented by the :mod:`random` and :mod:`itertools` modules
+   respectively.
+
+   .. index:: single: nested scope
+
+nested scope
+   The ability to refer to a variable in an enclosing definition.  For instance, a
+   function defined inside another function can refer to variables in the outer
+   function.  Note that nested scopes work only for reference and not for
+   assignment which will always write to the innermost scope.  In contrast, local
+   variables both read and write in the innermost scope.  Likewise, global
+   variables read and write to the global namespace.
+
+   .. index:: single: new-style class
+
+new-style class
+   Any class that inherits from :class:`object`.  This includes all built-in types
+   like :class:`list` and :class:`dict`.  Only new-style classes can use Python's
+   newer, versatile features like :meth:`__slots__`, descriptors, properties,
+   :meth:`__getattribute__`, class methods, and static methods.
+
+   .. index:: single: Python3000
+
+Python3000
+   A mythical python release, not required to be backward compatible, with
+   telepathic interface.
+
+   .. index:: single: __slots__
+
+__slots__
+   A declaration inside a *new-style class* that saves memory by pre-declaring
+   space for instance attributes and eliminating instance dictionaries.  Though
+   popular, the technique is somewhat tricky to get right and is best reserved for
+   rare cases where there are large numbers of instances in a memory-critical
+   application.
+
+   .. index:: single: sequence
+
+sequence
+   An *iterable* which supports efficient element access using integer indices via
+   the :meth:`__getitem__` and :meth:`__len__` special methods.  Some built-in
+   sequence types are :class:`list`, :class:`str`, :class:`tuple`, and
+   :class:`unicode`. Note that :class:`dict` also supports :meth:`__getitem__` and
+   :meth:`__len__`, but is considered a mapping rather than a sequence because the
+   lookups use arbitrary *immutable* keys rather than integers.
+
+   .. index:: single: Zen of Python
+
+Zen of Python
+   Listing of Python design principles and philosophies that are helpful in
+   understanding and using the language.  The listing can be found by typing
+   "``import this``" at the interactive prompt.
+
diff --git a/Doc/tutorial/index.rst b/Doc/tutorial/index.rst
new file mode 100644
index 0000000..7309b7c
--- /dev/null
+++ b/Doc/tutorial/index.rst
@@ -0,0 +1,60 @@
+.. _tutorial-index:
+
+######################
+  The Python tutorial 
+######################
+
+:Release: |version|
+:Date: |today|
+
+Python is an easy to learn, powerful programming language. It has efficient
+high-level data structures and a simple but effective approach to
+object-oriented programming. Python's elegant syntax and dynamic typing,
+together with its interpreted nature, make it an ideal language for scripting
+and rapid application development in many areas on most platforms.
+
+The Python interpreter and the extensive standard library are freely available
+in source or binary form for all major platforms from the Python Web site,
+http://www.python.org/, and may be freely distributed. The same site also
+contains distributions of and pointers to many free third party Python modules,
+programs and tools, and additional documentation.
+
+The Python interpreter is easily extended with new functions and data types
+implemented in C or C++ (or other languages callable from C). Python is also
+suitable as an extension language for customizable applications.
+
+This tutorial introduces the reader informally to the basic concepts and
+features of the Python language and system. It helps to have a Python
+interpreter handy for hands-on experience, but all examples are self-contained,
+so the tutorial can be read off-line as well.
+
+For a description of standard objects and modules, see the Python Library
+Reference document. The Python Reference Manual gives a more formal definition
+of the language. To write extensions in C or C++, read Extending and Embedding
+the Python Interpreter and Python/C API Reference. There are also several books
+covering Python in depth.
+
+This tutorial does not attempt to be comprehensive and cover every single
+feature, or even every commonly used feature. Instead, it introduces many of
+Python's most noteworthy features, and will give you a good idea of the
+language's flavor and style. After reading it, you will be able to read and
+write Python modules and programs, and you will be ready to learn more about the
+various Python library modules described in the Python Library Reference.
+
+.. toctree::
+
+   appetite.rst
+   interpreter.rst
+   introduction.rst
+   controlflow.rst
+   datastructures.rst
+   modules.rst
+   inputoutput.rst
+   errors.rst
+   classes.rst
+   stdlib.rst
+   stdlib2.rst
+   whatnow.rst
+   interactive.rst
+   floatingpoint.rst
+   glossary.rst
diff --git a/Doc/tutorial/inputoutput.rst b/Doc/tutorial/inputoutput.rst
new file mode 100644
index 0000000..9c302af
--- /dev/null
+++ b/Doc/tutorial/inputoutput.rst
@@ -0,0 +1,354 @@
+.. _tut-io:
+
+****************
+Input and Output
+****************
+
+There are several ways to present the output of a program; data can be printed
+in a human-readable form, or written to a file for future use. This chapter will
+discuss some of the possibilities.
+
+
+.. _tut-formatting:
+
+Fancier Output Formatting
+=========================
+
+So far we've encountered two ways of writing values: *expression statements* and
+the :keyword:`print` statement.  (A third way is using the :meth:`write` method
+of file objects; the standard output file can be referenced as ``sys.stdout``.
+See the Library Reference for more information on this.)
+
+.. index:: module: string
+
+Often you'll want more control over the formatting of your output than simply
+printing space-separated values.  There are two ways to format your output; the
+first way is to do all the string handling yourself; using string slicing and
+concatenation operations you can create any layout you can imagine.  The
+standard module :mod:`string` contains some useful operations for padding
+strings to a given column width; these will be discussed shortly.  The second
+way is to use the ``%`` operator with a string as the left argument.  The ``%``
+operator interprets the left argument much like a :cfunc:`sprintf`\ -style
+format string to be applied to the right argument, and returns the string
+resulting from this formatting operation.
+
+One question remains, of course: how do you convert values to strings? Luckily,
+Python has ways to convert any value to a string: pass it to the :func:`repr`
+or :func:`str` functions.  Reverse quotes (``````) are equivalent to
+:func:`repr`, but they are no longer used in modern Python code and will likely
+not be in future versions of the language.
+
+The :func:`str` function is meant to return representations of values which are
+fairly human-readable, while :func:`repr` is meant to generate representations
+which can be read by the interpreter (or will force a :exc:`SyntaxError` if
+there is not equivalent syntax).  For objects which don't have a particular
+representation for human consumption, :func:`str` will return the same value as
+:func:`repr`.  Many values, such as numbers or structures like lists and
+dictionaries, have the same representation using either function.  Strings and
+floating point numbers, in particular, have two distinct representations.
+
+Some examples::
+
+   >>> s = 'Hello, world.'
+   >>> str(s)
+   'Hello, world.'
+   >>> repr(s)
+   "'Hello, world.'"
+   >>> str(0.1)
+   '0.1'
+   >>> repr(0.1)
+   '0.10000000000000001'
+   >>> x = 10 * 3.25
+   >>> y = 200 * 200
+   >>> s = 'The value of x is ' + repr(x) + ', and y is ' + repr(y) + '...'
+   >>> print s
+   The value of x is 32.5, and y is 40000...
+   >>> # The repr() of a string adds string quotes and backslashes:
+   ... hello = 'hello, world\n'
+   >>> hellos = repr(hello)
+   >>> print hellos
+   'hello, world\n'
+   >>> # The argument to repr() may be any Python object:
+   ... repr((x, y, ('spam', 'eggs')))
+   "(32.5, 40000, ('spam', 'eggs'))"
+   >>> # reverse quotes are convenient in interactive sessions:
+   ... `x, y, ('spam', 'eggs')`
+   "(32.5, 40000, ('spam', 'eggs'))"
+
+Here are two ways to write a table of squares and cubes::
+
+   >>> for x in range(1, 11):
+   ...     print repr(x).rjust(2), repr(x*x).rjust(3),
+   ...     # Note trailing comma on previous line
+   ...     print repr(x*x*x).rjust(4)
+   ...
+    1   1    1
+    2   4    8
+    3   9   27
+    4  16   64
+    5  25  125
+    6  36  216
+    7  49  343
+    8  64  512
+    9  81  729
+   10 100 1000
+
+   >>> for x in range(1,11):
+   ...     print '%2d %3d %4d' % (x, x*x, x*x*x)
+   ... 
+    1   1    1
+    2   4    8
+    3   9   27
+    4  16   64
+    5  25  125
+    6  36  216
+    7  49  343
+    8  64  512
+    9  81  729
+   10 100 1000
+
+(Note that in the first example, one space between each column was added by the
+way :keyword:`print` works: it always adds spaces between its arguments.)
+
+This example demonstrates the :meth:`rjust` method of string objects, which
+right-justifies a string in a field of a given width by padding it with spaces
+on the left.  There are similar methods :meth:`ljust` and :meth:`center`.  These
+methods do not write anything, they just return a new string.  If the input
+string is too long, they don't truncate it, but return it unchanged; this will
+mess up your column lay-out but that's usually better than the alternative,
+which would be lying about a value.  (If you really want truncation you can
+always add a slice operation, as in ``x.ljust(n)[:n]``.)
+
+There is another method, :meth:`zfill`, which pads a numeric string on the left
+with zeros.  It understands about plus and minus signs::
+
+   >>> '12'.zfill(5)
+   '00012'
+   >>> '-3.14'.zfill(7)
+   '-003.14'
+   >>> '3.14159265359'.zfill(5)
+   '3.14159265359'
+
+Using the ``%`` operator looks like this::
+
+   >>> import math
+   >>> print 'The value of PI is approximately %5.3f.' % math.pi
+   The value of PI is approximately 3.142.
+
+If there is more than one format in the string, you need to pass a tuple as
+right operand, as in this example::
+
+   >>> table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 7678}
+   >>> for name, phone in table.items():
+   ...     print '%-10s ==> %10d' % (name, phone)
+   ... 
+   Jack       ==>       4098
+   Dcab       ==>       7678
+   Sjoerd     ==>       4127
+
+Most formats work exactly as in C and require that you pass the proper type;
+however, if you don't you get an exception, not a core dump. The ``%s`` format
+is more relaxed: if the corresponding argument is not a string object, it is
+converted to string using the :func:`str` built-in function.  Using ``*`` to
+pass the width or precision in as a separate (integer) argument is supported.
+The C formats ``%n`` and ``%p`` are not supported.
+
+If you have a really long format string that you don't want to split up, it
+would be nice if you could reference the variables to be formatted by name
+instead of by position.  This can be done by using form ``%(name)format``, as
+shown here::
+
+   >>> table = {'Sjoerd': 4127, 'Jack': 4098, 'Dcab': 8637678}
+   >>> print 'Jack: %(Jack)d; Sjoerd: %(Sjoerd)d; Dcab: %(Dcab)d' % table
+   Jack: 4098; Sjoerd: 4127; Dcab: 8637678
+
+This is particularly useful in combination with the new built-in :func:`vars`
+function, which returns a dictionary containing all local variables.
+
+
+.. _tut-files:
+
+Reading and Writing Files
+=========================
+
+.. index::
+   builtin: open
+   object: file
+
+:func:`open` returns a file object, and is most commonly used with two
+arguments: ``open(filename, mode)``.
+
+.. % Opening files
+
+::
+
+   >>> f=open('/tmp/workfile', 'w')
+   >>> print f
+   <open file '/tmp/workfile', mode 'w' at 80a0960>
+
+The first argument is a string containing the filename.  The second argument is
+another string containing a few characters describing the way in which the file
+will be used.  *mode* can be ``'r'`` when the file will only be read, ``'w'``
+for only writing (an existing file with the same name will be erased), and
+``'a'`` opens the file for appending; any data written to the file is
+automatically added to the end.  ``'r+'`` opens the file for both reading and
+writing. The *mode* argument is optional; ``'r'`` will be assumed if it's
+omitted.
+
+On Windows and the Macintosh, ``'b'`` appended to the mode opens the file in
+binary mode, so there are also modes like ``'rb'``, ``'wb'``, and ``'r+b'``.
+Windows makes a distinction between text and binary files; the end-of-line
+characters in text files are automatically altered slightly when data is read or
+written.  This behind-the-scenes modification to file data is fine for ASCII
+text files, but it'll corrupt binary data like that in :file:`JPEG` or
+:file:`EXE` files.  Be very careful to use binary mode when reading and writing
+such files.
+
+
+.. _tut-filemethods:
+
+Methods of File Objects
+-----------------------
+
+The rest of the examples in this section will assume that a file object called
+``f`` has already been created.
+
+To read a file's contents, call ``f.read(size)``, which reads some quantity of
+data and returns it as a string.  *size* is an optional numeric argument.  When
+*size* is omitted or negative, the entire contents of the file will be read and
+returned; it's your problem if the file is twice as large as your machine's
+memory. Otherwise, at most *size* bytes are read and returned.  If the end of
+the file has been reached, ``f.read()`` will return an empty string (``""``).
+::
+
+   >>> f.read()
+   'This is the entire file.\n'
+   >>> f.read()
+   ''
+
+``f.readline()`` reads a single line from the file; a newline character (``\n``)
+is left at the end of the string, and is only omitted on the last line of the
+file if the file doesn't end in a newline.  This makes the return value
+unambiguous; if ``f.readline()`` returns an empty string, the end of the file
+has been reached, while a blank line is represented by ``'\n'``, a string
+containing only a single newline.   ::
+
+   >>> f.readline()
+   'This is the first line of the file.\n'
+   >>> f.readline()
+   'Second line of the file\n'
+   >>> f.readline()
+   ''
+
+``f.readlines()`` returns a list containing all the lines of data in the file.
+If given an optional parameter *sizehint*, it reads that many bytes from the
+file and enough more to complete a line, and returns the lines from that.  This
+is often used to allow efficient reading of a large file by lines, but without
+having to load the entire file in memory.  Only complete lines will be returned.
+::
+
+   >>> f.readlines()
+   ['This is the first line of the file.\n', 'Second line of the file\n']
+
+An alternate approach to reading lines is to loop over the file object. This is
+memory efficient, fast, and leads to simpler code::
+
+   >>> for line in f:
+           print line,
+
+   This is the first line of the file.
+   Second line of the file
+
+The alternative approach is simpler but does not provide as fine-grained
+control.  Since the two approaches manage line buffering differently, they
+should not be mixed.
+
+``f.write(string)`` writes the contents of *string* to the file, returning
+``None``.   ::
+
+   >>> f.write('This is a test\n')
+
+To write something other than a string, it needs to be converted to a string
+first::
+
+   >>> value = ('the answer', 42)
+   >>> s = str(value)
+   >>> f.write(s)
+
+``f.tell()`` returns an integer giving the file object's current position in the
+file, measured in bytes from the beginning of the file.  To change the file
+object's position, use ``f.seek(offset, from_what)``.  The position is computed
+from adding *offset* to a reference point; the reference point is selected by
+the *from_what* argument.  A *from_what* value of 0 measures from the beginning
+of the file, 1 uses the current file position, and 2 uses the end of the file as
+the reference point.  *from_what* can be omitted and defaults to 0, using the
+beginning of the file as the reference point. ::
+
+   >>> f = open('/tmp/workfile', 'r+')
+   >>> f.write('0123456789abcdef')
+   >>> f.seek(5)     # Go to the 6th byte in the file
+   >>> f.read(1)        
+   '5'
+   >>> f.seek(-3, 2) # Go to the 3rd byte before the end
+   >>> f.read(1)
+   'd'
+
+When you're done with a file, call ``f.close()`` to close it and free up any
+system resources taken up by the open file.  After calling ``f.close()``,
+attempts to use the file object will automatically fail. ::
+
+   >>> f.close()
+   >>> f.read()
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   ValueError: I/O operation on closed file
+
+File objects have some additional methods, such as :meth:`isatty` and
+:meth:`truncate` which are less frequently used; consult the Library Reference
+for a complete guide to file objects.
+
+
+.. _tut-pickle:
+
+The :mod:`pickle` Module
+------------------------
+
+.. index:: module: pickle
+
+Strings can easily be written to and read from a file. Numbers take a bit more
+effort, since the :meth:`read` method only returns strings, which will have to
+be passed to a function like :func:`int`, which takes a string like ``'123'``
+and returns its numeric value 123.  However, when you want to save more complex
+data types like lists, dictionaries, or class instances, things get a lot more
+complicated.
+
+Rather than have users be constantly writing and debugging code to save
+complicated data types, Python provides a standard module called :mod:`pickle`.
+This is an amazing module that can take almost any Python object (even some
+forms of Python code!), and convert it to a string representation; this process
+is called :dfn:`pickling`.  Reconstructing the object from the string
+representation is called :dfn:`unpickling`.  Between pickling and unpickling,
+the string representing the object may have been stored in a file or data, or
+sent over a network connection to some distant machine.
+
+If you have an object ``x``, and a file object ``f`` that's been opened for
+writing, the simplest way to pickle the object takes only one line of code::
+
+   pickle.dump(x, f)
+
+To unpickle the object again, if ``f`` is a file object which has been opened
+for reading::
+
+   x = pickle.load(f)
+
+(There are other variants of this, used when pickling many objects or when you
+don't want to write the pickled data to a file; consult the complete
+documentation for :mod:`pickle` in the Python Library Reference.)
+
+:mod:`pickle` is the standard way to make Python objects which can be stored and
+reused by other programs or by a future invocation of the same program; the
+technical term for this is a :dfn:`persistent` object.  Because :mod:`pickle` is
+so widely used, many authors who write Python extensions take care to ensure
+that new data types such as matrices can be properly pickled and unpickled.
+
+
diff --git a/Doc/tutorial/interactive.rst b/Doc/tutorial/interactive.rst
new file mode 100644
index 0000000..8eeca2a
--- /dev/null
+++ b/Doc/tutorial/interactive.rst
@@ -0,0 +1,167 @@
+.. _tut-interacting:
+
+**************************************************
+Interactive Input Editing and History Substitution
+**************************************************
+
+Some versions of the Python interpreter support editing of the current input
+line and history substitution, similar to facilities found in the Korn shell and
+the GNU Bash shell.  This is implemented using the *GNU Readline* library, which
+supports Emacs-style and vi-style editing.  This library has its own
+documentation which I won't duplicate here; however, the basics are easily
+explained.  The interactive editing and history described here are optionally
+available in the Unix and Cygwin versions of the interpreter.
+
+This chapter does *not* document the editing facilities of Mark Hammond's
+PythonWin package or the Tk-based environment, IDLE, distributed with Python.
+The command line history recall which operates within DOS boxes on NT and some
+other DOS and Windows flavors  is yet another beast.
+
+
+.. _tut-lineediting:
+
+Line Editing
+============
+
+If supported, input line editing is active whenever the interpreter prints a
+primary or secondary prompt.  The current line can be edited using the
+conventional Emacs control characters.  The most important of these are:
+:kbd:`C-A` (Control-A) moves the cursor to the beginning of the line, :kbd:`C-E`
+to the end, :kbd:`C-B` moves it one position to the left, :kbd:`C-F` to the
+right.  Backspace erases the character to the left of the cursor, :kbd:`C-D` the
+character to its right. :kbd:`C-K` kills (erases) the rest of the line to the
+right of the cursor, :kbd:`C-Y` yanks back the last killed string.
+:kbd:`C-underscore` undoes the last change you made; it can be repeated for
+cumulative effect.
+
+
+.. _tut-history:
+
+History Substitution
+====================
+
+History substitution works as follows.  All non-empty input lines issued are
+saved in a history buffer, and when a new prompt is given you are positioned on
+a new line at the bottom of this buffer. :kbd:`C-P` moves one line up (back) in
+the history buffer, :kbd:`C-N` moves one down.  Any line in the history buffer
+can be edited; an asterisk appears in front of the prompt to mark a line as
+modified.  Pressing the :kbd:`Return` key passes the current line to the
+interpreter.  :kbd:`C-R` starts an incremental reverse search; :kbd:`C-S` starts
+a forward search.
+
+
+.. _tut-keybindings:
+
+Key Bindings
+============
+
+The key bindings and some other parameters of the Readline library can be
+customized by placing commands in an initialization file called
+:file:`~/.inputrc`.  Key bindings have the form ::
+
+   key-name: function-name
+
+or ::
+
+   "string": function-name
+
+and options can be set with ::
+
+   set option-name value
+
+For example::
+
+   # I prefer vi-style editing:
+   set editing-mode vi
+
+   # Edit using a single line:
+   set horizontal-scroll-mode On
+
+   # Rebind some keys:
+   Meta-h: backward-kill-word
+   "\C-u": universal-argument
+   "\C-x\C-r": re-read-init-file
+
+Note that the default binding for :kbd:`Tab` in Python is to insert a :kbd:`Tab`
+character instead of Readline's default filename completion function.  If you
+insist, you can override this by putting ::
+
+   Tab: complete
+
+in your :file:`~/.inputrc`.  (Of course, this makes it harder to type indented
+continuation lines if you're accustomed to using :kbd:`Tab` for that purpose.)
+
+.. index::
+   module: rlcompleter
+   module: readline
+
+Automatic completion of variable and module names is optionally available.  To
+enable it in the interpreter's interactive mode, add the following to your
+startup file: [#]_  ::
+
+   import rlcompleter, readline
+   readline.parse_and_bind('tab: complete')
+
+This binds the :kbd:`Tab` key to the completion function, so hitting the
+:kbd:`Tab` key twice suggests completions; it looks at Python statement names,
+the current local variables, and the available module names.  For dotted
+expressions such as ``string.a``, it will evaluate the expression up to the
+final ``'.'`` and then suggest completions from the attributes of the resulting
+object.  Note that this may execute application-defined code if an object with a
+:meth:`__getattr__` method is part of the expression.
+
+A more capable startup file might look like this example.  Note that this
+deletes the names it creates once they are no longer needed; this is done since
+the startup file is executed in the same namespace as the interactive commands,
+and removing the names avoids creating side effects in the interactive
+environment.  You may find it convenient to keep some of the imported modules,
+such as :mod:`os`, which turn out to be needed in most sessions with the
+interpreter. ::
+
+   # Add auto-completion and a stored history file of commands to your Python
+   # interactive interpreter. Requires Python 2.0+, readline. Autocomplete is
+   # bound to the Esc key by default (you can change it - see readline docs).
+   #
+   # Store the file in ~/.pystartup, and set an environment variable to point
+   # to it:  "export PYTHONSTARTUP=/max/home/itamar/.pystartup" in bash.
+   #
+   # Note that PYTHONSTARTUP does *not* expand "~", so you have to put in the
+   # full path to your home directory.
+
+   import atexit
+   import os
+   import readline
+   import rlcompleter
+
+   historyPath = os.path.expanduser("~/.pyhistory")
+
+   def save_history(historyPath=historyPath):
+       import readline
+       readline.write_history_file(historyPath)
+
+   if os.path.exists(historyPath):
+       readline.read_history_file(historyPath)
+
+   atexit.register(save_history)
+   del os, atexit, readline, rlcompleter, save_history, historyPath
+
+
+.. _tut-commentary:
+
+Commentary
+==========
+
+This facility is an enormous step forward compared to earlier versions of the
+interpreter; however, some wishes are left: It would be nice if the proper
+indentation were suggested on continuation lines (the parser knows if an indent
+token is required next).  The completion mechanism might use the interpreter's
+symbol table.  A command to check (or even suggest) matching parentheses,
+quotes, etc., would also be useful.
+
+
+.. rubric:: Footnotes
+
+.. [#] Python will execute the contents of a file identified by the
+   :envvar:`PYTHONSTARTUP` environment variable when you start an interactive
+   interpreter.
+
diff --git a/Doc/tutorial/interpreter.rst b/Doc/tutorial/interpreter.rst
new file mode 100644
index 0000000..8b42090
--- /dev/null
+++ b/Doc/tutorial/interpreter.rst
@@ -0,0 +1,248 @@
+.. _tut-using:
+
+****************************
+Using the Python Interpreter
+****************************
+
+
+.. _tut-invoking:
+
+Invoking the Interpreter
+========================
+
+The Python interpreter is usually installed as :file:`/usr/local/bin/python` on
+those machines where it is available; putting :file:`/usr/local/bin` in your
+Unix shell's search path makes it possible to start it by typing the command ::
+
+   python
+
+to the shell.  Since the choice of the directory where the interpreter lives is
+an installation option, other places are possible; check with your local Python
+guru or system administrator.  (E.g., :file:`/usr/local/python` is a popular
+alternative location.)
+
+On Windows machines, the Python installation is usually placed in
+:file:`C:\Python30`, though you can change this when you're running the
+installer.  To add this directory to your path,  you can type the following
+command into the command prompt in a DOS box::
+
+   set path=%path%;C:\python30
+
+Typing an end-of-file character (:kbd:`Control-D` on Unix, :kbd:`Control-Z` on
+Windows) at the primary prompt causes the interpreter to exit with a zero exit
+status.  If that doesn't work, you can exit the interpreter by typing the
+following commands: ``import sys; sys.exit()``.
+
+The interpreter's line-editing features usually aren't very sophisticated.  On
+Unix, whoever installed the interpreter may have enabled support for the GNU
+readline library, which adds more elaborate interactive editing and history
+features. Perhaps the quickest check to see whether command line editing is
+supported is typing Control-P to the first Python prompt you get.  If it beeps,
+you have command line editing; see Appendix :ref:`tut-interacting` for an
+introduction to the keys.  If nothing appears to happen, or if ``^P`` is echoed,
+command line editing isn't available; you'll only be able to use backspace to
+remove characters from the current line.
+
+The interpreter operates somewhat like the Unix shell: when called with standard
+input connected to a tty device, it reads and executes commands interactively;
+when called with a file name argument or with a file as standard input, it reads
+and executes a *script* from that file.
+
+A second way of starting the interpreter is ``python -c command [arg] ...``,
+which executes the statement(s) in *command*, analogous to the shell's
+:option:`-c` option.  Since Python statements often contain spaces or other
+characters that are special to the shell, it is best to quote  *command* in its
+entirety with double quotes.
+
+Some Python modules are also useful as scripts.  These can be invoked using
+``python -m module [arg] ...``, which executes the source file for *module* as
+if you had spelled out its full name on the command line.
+
+Note that there is a difference between ``python file`` and ``python <file``.
+In the latter case, input requests from the program, such as calling
+``sys.stdin.read()``, are satisfied from *file*.  Since this file has already
+been read until the end by the parser before the program starts executing, the
+program will encounter end-of-file immediately.  In the former case (which is
+usually what you want) they are satisfied from whatever file or device is
+connected to standard input of the Python interpreter.
+
+When a script file is used, it is sometimes useful to be able to run the script
+and enter interactive mode afterwards.  This can be done by passing :option:`-i`
+before the script.  (This does not work if the script is read from standard
+input, for the same reason as explained in the previous paragraph.)
+
+
+.. _tut-argpassing:
+
+Argument Passing
+----------------
+
+When known to the interpreter, the script name and additional arguments
+thereafter are passed to the script in the variable ``sys.argv``, which is a
+list of strings.  Its length is at least one; when no script and no arguments
+are given, ``sys.argv[0]`` is an empty string.  When the script name is given as
+``'-'`` (meaning  standard input), ``sys.argv[0]`` is set to ``'-'``.  When
+:option:`-c` *command* is used, ``sys.argv[0]`` is set to ``'-c'``.  When
+:option:`-m` *module* is used, ``sys.argv[0]``  is set to the full name of the
+located module.  Options found after  :option:`-c` *command* or :option:`-m`
+*module* are not consumed  by the Python interpreter's option processing but
+left in ``sys.argv`` for  the command or module to handle.
+
+
+.. _tut-interactive:
+
+Interactive Mode
+----------------
+
+When commands are read from a tty, the interpreter is said to be in *interactive
+mode*.  In this mode it prompts for the next command with the *primary prompt*,
+usually three greater-than signs (``>>>``); for continuation lines it prompts
+with the *secondary prompt*, by default three dots (``...``). The interpreter
+prints a welcome message stating its version number and a copyright notice
+before printing the first prompt::
+
+   python
+   Python 1.5.2b2 (#1, Feb 28 1999, 00:02:06)  [GCC 2.8.1] on sunos5
+   Copyright 1991-1995 Stichting Mathematisch Centrum, Amsterdam
+   >>>
+
+Continuation lines are needed when entering a multi-line construct. As an
+example, take a look at this :keyword:`if` statement::
+
+   >>> the_world_is_flat = 1
+   >>> if the_world_is_flat:
+   ...     print "Be careful not to fall off!"
+   ... 
+   Be careful not to fall off!
+
+
+.. _tut-interp:
+
+The Interpreter and Its Environment
+===================================
+
+
+.. _tut-error:
+
+Error Handling
+--------------
+
+When an error occurs, the interpreter prints an error message and a stack trace.
+In interactive mode, it then returns to the primary prompt; when input came from
+a file, it exits with a nonzero exit status after printing the stack trace.
+(Exceptions handled by an :keyword:`except` clause in a :keyword:`try` statement
+are not errors in this context.)  Some errors are unconditionally fatal and
+cause an exit with a nonzero exit; this applies to internal inconsistencies and
+some cases of running out of memory.  All error messages are written to the
+standard error stream; normal output from executed commands is written to
+standard output.
+
+Typing the interrupt character (usually Control-C or DEL) to the primary or
+secondary prompt cancels the input and returns to the primary prompt. [#]_
+Typing an interrupt while a command is executing raises the
+:exc:`KeyboardInterrupt` exception, which may be handled by a :keyword:`try`
+statement.
+
+
+.. _tut-scripts:
+
+Executable Python Scripts
+-------------------------
+
+On BSD'ish Unix systems, Python scripts can be made directly executable, like
+shell scripts, by putting the line ::
+
+   #! /usr/bin/env python
+
+(assuming that the interpreter is on the user's :envvar:`PATH`) at the beginning
+of the script and giving the file an executable mode.  The ``#!`` must be the
+first two characters of the file.  On some platforms, this first line must end
+with a Unix-style line ending (``'\n'``), not a Mac OS (``'\r'``) or Windows
+(``'\r\n'``) line ending.  Note that the hash, or pound, character, ``'#'``, is
+used to start a comment in Python.
+
+The script can be given an executable mode, or permission, using the
+:program:`chmod` command::
+
+   $ chmod +x myscript.py
+
+
+Source Code Encoding
+--------------------
+
+It is possible to use encodings different than ASCII in Python source files. The
+best way to do it is to put one more special comment line right after the ``#!``
+line to define the source file encoding::
+
+   # -*- coding: encoding -*- 
+
+
+With that declaration, all characters in the source file will be treated as
+having the encoding *encoding*, and it will be possible to directly write
+Unicode string literals in the selected encoding.  The list of possible
+encodings can be found in the Python Library Reference, in the section on
+:mod:`codecs`.
+
+For example, to write Unicode literals including the Euro currency symbol, the
+ISO-8859-15 encoding can be used, with the Euro symbol having the ordinal value
+164.  This script will print the value 8364 (the Unicode codepoint corresponding
+to the Euro symbol) and then exit::
+
+   # -*- coding: iso-8859-15 -*-
+
+   currency = u"€"
+   print ord(currency)
+
+If your editor supports saving files as ``UTF-8`` with a UTF-8 *byte order mark*
+(aka BOM), you can use that instead of an encoding declaration. IDLE supports
+this capability if ``Options/General/Default Source Encoding/UTF-8`` is set.
+Notice that this signature is not understood in older Python releases (2.2 and
+earlier), and also not understood by the operating system for script files with
+``#!`` lines (only used on Unix systems).
+
+By using UTF-8 (either through the signature or an encoding declaration),
+characters of most languages in the world can be used simultaneously in string
+literals and comments.  Using non-ASCII characters in identifiers is not
+supported. To display all these characters properly, your editor must recognize
+that the file is UTF-8, and it must use a font that supports all the characters
+in the file.
+
+
+.. _tut-startup:
+
+The Interactive Startup File
+----------------------------
+
+When you use Python interactively, it is frequently handy to have some standard
+commands executed every time the interpreter is started.  You can do this by
+setting an environment variable named :envvar:`PYTHONSTARTUP` to the name of a
+file containing your start-up commands.  This is similar to the :file:`.profile`
+feature of the Unix shells.
+
+.. % XXX This should probably be dumped in an appendix, since most people
+.. % don't use Python interactively in non-trivial ways.
+
+This file is only read in interactive sessions, not when Python reads commands
+from a script, and not when :file:`/dev/tty` is given as the explicit source of
+commands (which otherwise behaves like an interactive session).  It is executed
+in the same namespace where interactive commands are executed, so that objects
+that it defines or imports can be used without qualification in the interactive
+session. You can also change the prompts ``sys.ps1`` and ``sys.ps2`` in this
+file.
+
+If you want to read an additional start-up file from the current directory, you
+can program this in the global start-up file using code like ``if
+os.path.isfile('.pythonrc.py'): exec(open('.pythonrc.py').read())``.
+If you want to use the startup file in a script, you must do this explicitly
+in the script::
+
+   import os
+   filename = os.environ.get('PYTHONSTARTUP')
+   if filename and os.path.isfile(filename):
+       exec(open(filename).read())
+
+
+.. rubric:: Footnotes
+
+.. [#] A problem with the GNU Readline package may prevent this.
+
diff --git a/Doc/tutorial/introduction.rst b/Doc/tutorial/introduction.rst
new file mode 100644
index 0000000..e209bfc
--- /dev/null
+++ b/Doc/tutorial/introduction.rst
@@ -0,0 +1,645 @@
+.. _tut-informal:
+
+**********************************
+An Informal Introduction to Python
+**********************************
+
+In the following examples, input and output are distinguished by the presence or
+absence of prompts (``>>>`` and ``...``): to repeat the example, you must type
+everything after the prompt, when the prompt appears; lines that do not begin
+with a prompt are output from the interpreter. Note that a secondary prompt on a
+line by itself in an example means you must type a blank line; this is used to
+end a multi-line command.
+
+.. % 
+.. % \footnote{
+.. % I'd prefer to use different fonts to distinguish input
+.. % from output, but the amount of LaTeX hacking that would require
+.. % is currently beyond my ability.
+.. % }
+
+Many of the examples in this manual, even those entered at the interactive
+prompt, include comments.  Comments in Python start with the hash character,
+``'#'``, and extend to the end of the physical line.  A comment may appear at
+the start of a line or following whitespace or code, but not within a string
+literal.  A hash  character within a string literal is just a hash character.
+
+Some examples::
+
+   # this is the first comment
+   SPAM = 1                 # and this is the second comment
+                            # ... and now a third!
+   STRING = "# This is not a comment."
+
+
+.. _tut-calculator:
+
+Using Python as a Calculator
+============================
+
+Let's try some simple Python commands.  Start the interpreter and wait for the
+primary prompt, ``>>>``.  (It shouldn't take long.)
+
+
+.. _tut-numbers:
+
+Numbers
+-------
+
+The interpreter acts as a simple calculator: you can type an expression at it
+and it will write the value.  Expression syntax is straightforward: the
+operators ``+``, ``-``, ``*`` and ``/`` work just like in most other languages
+(for example, Pascal or C); parentheses can be used for grouping.  For example::
+
+   >>> 2+2
+   4
+   >>> # This is a comment
+   ... 2+2
+   4
+   >>> 2+2  # and a comment on the same line as code
+   4
+   >>> (50-5*6)/4
+   5
+   >>> # Integer division returns the floor:
+   ... 7/3
+   2
+   >>> 7/-3
+   -3
+
+The equal sign (``'='``) is used to assign a value to a variable. Afterwards, no
+result is displayed before the next interactive prompt::
+
+   >>> width = 20
+   >>> height = 5*9
+   >>> width * height
+   900
+
+A value can be assigned to several variables simultaneously::
+
+   >>> x = y = z = 0  # Zero x, y and z
+   >>> x
+   0
+   >>> y
+   0
+   >>> z
+   0
+
+There is full support for floating point; operators with mixed type operands
+convert the integer operand to floating point::
+
+   >>> 3 * 3.75 / 1.5
+   7.5
+   >>> 7.0 / 2
+   3.5
+
+Complex numbers are also supported; imaginary numbers are written with a suffix
+of ``j`` or ``J``.  Complex numbers with a nonzero real component are written as
+``(real+imagj)``, or can be created with the ``complex(real, imag)`` function.
+::
+
+   >>> 1j * 1J
+   (-1+0j)
+   >>> 1j * complex(0,1)
+   (-1+0j)
+   >>> 3+1j*3
+   (3+3j)
+   >>> (3+1j)*3
+   (9+3j)
+   >>> (1+2j)/(1+1j)
+   (1.5+0.5j)
+
+Complex numbers are always represented as two floating point numbers, the real
+and imaginary part.  To extract these parts from a complex number *z*, use
+``z.real`` and ``z.imag``.   ::
+
+   >>> a=1.5+0.5j
+   >>> a.real
+   1.5
+   >>> a.imag
+   0.5
+
+The conversion functions to floating point and integer (:func:`float`,
+:func:`int` and :func:`long`) don't work for complex numbers --- there is no one
+correct way to convert a complex number to a real number.  Use ``abs(z)`` to get
+its magnitude (as a float) or ``z.real`` to get its real part. ::
+
+   >>> a=3.0+4.0j
+   >>> float(a)
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   TypeError: can't convert complex to float; use abs(z)
+   >>> a.real
+   3.0
+   >>> a.imag
+   4.0
+   >>> abs(a)  # sqrt(a.real**2 + a.imag**2)
+   5.0
+   >>>
+
+In interactive mode, the last printed expression is assigned to the variable
+``_``.  This means that when you are using Python as a desk calculator, it is
+somewhat easier to continue calculations, for example::
+
+   >>> tax = 12.5 / 100
+   >>> price = 100.50
+   >>> price * tax
+   12.5625
+   >>> price + _
+   113.0625
+   >>> round(_, 2)
+   113.06
+   >>>
+
+This variable should be treated as read-only by the user.  Don't explicitly
+assign a value to it --- you would create an independent local variable with the
+same name masking the built-in variable with its magic behavior.
+
+
+.. _tut-strings:
+
+Strings
+-------
+
+Besides numbers, Python can also manipulate strings, which can be expressed in
+several ways.  They can be enclosed in single quotes or double quotes::
+
+   >>> 'spam eggs'
+   'spam eggs'
+   >>> 'doesn\'t'
+   "doesn't"
+   >>> "doesn't"
+   "doesn't"
+   >>> '"Yes," he said.'
+   '"Yes," he said.'
+   >>> "\"Yes,\" he said."
+   '"Yes," he said.'
+   >>> '"Isn\'t," she said.'
+   '"Isn\'t," she said.'
+
+String literals can span multiple lines in several ways.  Continuation lines can
+be used, with a backslash as the last character on the line indicating that the
+next line is a logical continuation of the line::
+
+   hello = "This is a rather long string containing\n\
+   several lines of text just as you would do in C.\n\
+       Note that whitespace at the beginning of the line is\
+    significant."
+
+   print hello
+
+Note that newlines still need to be embedded in the string using ``\n``; the
+newline following the trailing backslash is discarded.  This example would print
+the following::
+
+   This is a rather long string containing
+   several lines of text just as you would do in C.
+       Note that whitespace at the beginning of the line is significant.
+
+If we make the string literal a "raw" string, however, the ``\n`` sequences are
+not converted to newlines, but the backslash at the end of the line, and the
+newline character in the source, are both included in the string as data.  Thus,
+the example::
+
+   hello = r"This is a rather long string containing\n\
+   several lines of text much as you would do in C."
+
+   print hello
+
+would print::
+
+   This is a rather long string containing\n\
+   several lines of text much as you would do in C.
+
+Or, strings can be surrounded in a pair of matching triple-quotes: ``"""`` or
+``'''``.  End of lines do not need to be escaped when using triple-quotes, but
+they will be included in the string. ::
+
+   print """
+   Usage: thingy [OPTIONS] 
+        -h                        Display this usage message
+        -H hostname               Hostname to connect to
+   """
+
+produces the following output::
+
+   Usage: thingy [OPTIONS] 
+        -h                        Display this usage message
+        -H hostname               Hostname to connect to
+
+The interpreter prints the result of string operations in the same way as they
+are typed for input: inside quotes, and with quotes and other funny characters
+escaped by backslashes, to show the precise value.  The string is enclosed in
+double quotes if the string contains a single quote and no double quotes, else
+it's enclosed in single quotes.  (The :keyword:`print` statement, described
+later, can be used to write strings without quotes or escapes.)
+
+Strings can be concatenated (glued together) with the ``+`` operator, and
+repeated with ``*``::
+
+   >>> word = 'Help' + 'A'
+   >>> word
+   'HelpA'
+   >>> '<' + word*5 + '>'
+   '<HelpAHelpAHelpAHelpAHelpA>'
+
+Two string literals next to each other are automatically concatenated; the first
+line above could also have been written ``word = 'Help' 'A'``; this only works
+with two literals, not with arbitrary string expressions::
+
+   >>> 'str' 'ing'                   #  <-  This is ok
+   'string'
+   >>> 'str'.strip() + 'ing'   #  <-  This is ok
+   'string'
+   >>> 'str'.strip() 'ing'     #  <-  This is invalid
+     File "<stdin>", line 1, in ?
+       'str'.strip() 'ing'
+                         ^
+   SyntaxError: invalid syntax
+
+Strings can be subscripted (indexed); like in C, the first character of a string
+has subscript (index) 0.  There is no separate character type; a character is
+simply a string of size one.  Like in Icon, substrings can be specified with the
+*slice notation*: two indices separated by a colon. ::
+
+   >>> word[4]
+   'A'
+   >>> word[0:2]
+   'He'
+   >>> word[2:4]
+   'lp'
+
+Slice indices have useful defaults; an omitted first index defaults to zero, an
+omitted second index defaults to the size of the string being sliced. ::
+
+   >>> word[:2]    # The first two characters
+   'He'
+   >>> word[2:]    # Everything except the first two characters
+   'lpA'
+
+Unlike a C string, Python strings cannot be changed.  Assigning to an  indexed
+position in the string results in an error::
+
+   >>> word[0] = 'x'
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   TypeError: object doesn't support item assignment
+   >>> word[:1] = 'Splat'
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   TypeError: object doesn't support slice assignment
+
+However, creating a new string with the combined content is easy and efficient::
+
+   >>> 'x' + word[1:]
+   'xelpA'
+   >>> 'Splat' + word[4]
+   'SplatA'
+
+Here's a useful invariant of slice operations: ``s[:i] + s[i:]`` equals ``s``.
+::
+
+   >>> word[:2] + word[2:]
+   'HelpA'
+   >>> word[:3] + word[3:]
+   'HelpA'
+
+Degenerate slice indices are handled gracefully: an index that is too large is
+replaced by the string size, an upper bound smaller than the lower bound returns
+an empty string. ::
+
+   >>> word[1:100]
+   'elpA'
+   >>> word[10:]
+   ''
+   >>> word[2:1]
+   ''
+
+Indices may be negative numbers, to start counting from the right. For example::
+
+   >>> word[-1]     # The last character
+   'A'
+   >>> word[-2]     # The last-but-one character
+   'p'
+   >>> word[-2:]    # The last two characters
+   'pA'
+   >>> word[:-2]    # Everything except the last two characters
+   'Hel'
+
+But note that -0 is really the same as 0, so it does not count from the right!
+::
+
+   >>> word[-0]     # (since -0 equals 0)
+   'H'
+
+Out-of-range negative slice indices are truncated, but don't try this for
+single-element (non-slice) indices::
+
+   >>> word[-100:]
+   'HelpA'
+   >>> word[-10]    # error
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   IndexError: string index out of range
+
+One way to remember how slices work is to think of the indices as pointing
+*between* characters, with the left edge of the first character numbered 0.
+Then the right edge of the last character of a string of *n* characters has
+index *n*, for example::
+
+    +---+---+---+---+---+ 
+    | H | e | l | p | A |
+    +---+---+---+---+---+ 
+    0   1   2   3   4   5 
+   -5  -4  -3  -2  -1
+
+The first row of numbers gives the position of the indices 0...5 in the string;
+the second row gives the corresponding negative indices. The slice from *i* to
+*j* consists of all characters between the edges labeled *i* and *j*,
+respectively.
+
+For non-negative indices, the length of a slice is the difference of the
+indices, if both are within bounds.  For example, the length of ``word[1:3]`` is
+2.
+
+The built-in function :func:`len` returns the length of a string::
+
+   >>> s = 'supercalifragilisticexpialidocious'
+   >>> len(s)
+   34
+
+
+.. seealso::
+
+   :ref:`typesseq`
+      Strings, and the Unicode strings described in the next section, are
+      examples of *sequence types*, and support the common operations supported
+      by such types.
+
+   :ref:`string-methods`
+      Both strings and Unicode strings support a large number of methods for
+      basic transformations and searching.
+
+   :ref:`string-formatting`
+      The formatting operations invoked when strings and Unicode strings are the
+      left operand of the ``%`` operator are described in more detail here.
+
+
+.. _tut-unicodestrings:
+
+Unicode Strings
+---------------
+
+.. sectionauthor:: Marc-Andre Lemburg <mal@lemburg.com>
+
+
+Starting with Python 2.0 a new data type for storing text data is available to
+the programmer: the Unicode object. It can be used to store and manipulate
+Unicode data (see http://www.unicode.org/) and integrates well with the existing
+string objects, providing auto-conversions where necessary.
+
+Unicode has the advantage of providing one ordinal for every character in every
+script used in modern and ancient texts. Previously, there were only 256
+possible ordinals for script characters. Texts were typically bound to a code
+page which mapped the ordinals to script characters. This lead to very much
+confusion especially with respect to internationalization (usually written as
+``i18n`` --- ``'i'`` + 18 characters + ``'n'``) of software.  Unicode solves
+these problems by defining one code page for all scripts.
+
+Creating Unicode strings in Python is just as simple as creating normal
+strings::
+
+   >>> u'Hello World !'
+   u'Hello World !'
+
+The small ``'u'`` in front of the quote indicates that a Unicode string is
+supposed to be created. If you want to include special characters in the string,
+you can do so by using the Python *Unicode-Escape* encoding. The following
+example shows how::
+
+   >>> u'Hello\u0020World !'
+   u'Hello World !'
+
+The escape sequence ``\u0020`` indicates to insert the Unicode character with
+the ordinal value 0x0020 (the space character) at the given position.
+
+Other characters are interpreted by using their respective ordinal values
+directly as Unicode ordinals.  If you have literal strings in the standard
+Latin-1 encoding that is used in many Western countries, you will find it
+convenient that the lower 256 characters of Unicode are the same as the 256
+characters of Latin-1.
+
+For experts, there is also a raw mode just like the one for normal strings. You
+have to prefix the opening quote with 'ur' to have Python use the
+*Raw-Unicode-Escape* encoding. It will only apply the above ``\uXXXX``
+conversion if there is an uneven number of backslashes in front of the small
+'u'. ::
+
+   >>> ur'Hello\u0020World !'
+   u'Hello World !'
+   >>> ur'Hello\\u0020World !'
+   u'Hello\\\\u0020World !'
+
+The raw mode is most useful when you have to enter lots of backslashes, as can
+be necessary in regular expressions.
+
+Apart from these standard encodings, Python provides a whole set of other ways
+of creating Unicode strings on the basis of a known encoding.
+
+.. index:: builtin: unicode
+
+The built-in function :func:`unicode` provides access to all registered Unicode
+codecs (COders and DECoders). Some of the more well known encodings which these
+codecs can convert are *Latin-1*, *ASCII*, *UTF-8*, and *UTF-16*. The latter two
+are variable-length encodings that store each Unicode character in one or more
+bytes. The default encoding is normally set to ASCII, which passes through
+characters in the range 0 to 127 and rejects any other characters with an error.
+When a Unicode string is printed, written to a file, or converted with
+:func:`str`, conversion takes place using this default encoding. ::
+
+   >>> u"abc"
+   u'abc'
+   >>> str(u"abc")
+   'abc'
+   >>> u"äöü"
+   u'\xe4\xf6\xfc'
+   >>> str(u"äöü")
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   UnicodeEncodeError: 'ascii' codec can't encode characters in position 0-2: ordinal not in range(128)
+
+To convert a Unicode string into an 8-bit string using a specific encoding,
+Unicode objects provide an :func:`encode` method that takes one argument, the
+name of the encoding.  Lowercase names for encodings are preferred. ::
+
+   >>> u"äöü".encode('utf-8')
+   '\xc3\xa4\xc3\xb6\xc3\xbc'
+
+If you have data in a specific encoding and want to produce a corresponding
+Unicode string from it, you can use the :func:`unicode` function with the
+encoding name as the second argument. ::
+
+   >>> unicode('\xc3\xa4\xc3\xb6\xc3\xbc', 'utf-8')
+   u'\xe4\xf6\xfc'
+
+
+.. _tut-lists:
+
+Lists
+-----
+
+Python knows a number of *compound* data types, used to group together other
+values.  The most versatile is the *list*, which can be written as a list of
+comma-separated values (items) between square brackets.  List items need not all
+have the same type. ::
+
+   >>> a = ['spam', 'eggs', 100, 1234]
+   >>> a
+   ['spam', 'eggs', 100, 1234]
+
+Like string indices, list indices start at 0, and lists can be sliced,
+concatenated and so on::
+
+   >>> a[0]
+   'spam'
+   >>> a[3]
+   1234
+   >>> a[-2]
+   100
+   >>> a[1:-1]
+   ['eggs', 100]
+   >>> a[:2] + ['bacon', 2*2]
+   ['spam', 'eggs', 'bacon', 4]
+   >>> 3*a[:3] + ['Boo!']
+   ['spam', 'eggs', 100, 'spam', 'eggs', 100, 'spam', 'eggs', 100, 'Boo!']
+
+Unlike strings, which are *immutable*, it is possible to change individual
+elements of a list::
+
+   >>> a
+   ['spam', 'eggs', 100, 1234]
+   >>> a[2] = a[2] + 23
+   >>> a
+   ['spam', 'eggs', 123, 1234]
+
+Assignment to slices is also possible, and this can even change the size of the
+list or clear it entirely::
+
+   >>> # Replace some items:
+   ... a[0:2] = [1, 12]
+   >>> a
+   [1, 12, 123, 1234]
+   >>> # Remove some:
+   ... a[0:2] = []
+   >>> a
+   [123, 1234]
+   >>> # Insert some:
+   ... a[1:1] = ['bletch', 'xyzzy']
+   >>> a
+   [123, 'bletch', 'xyzzy', 1234]
+   >>> # Insert (a copy of) itself at the beginning
+   >>> a[:0] = a
+   >>> a
+   [123, 'bletch', 'xyzzy', 1234, 123, 'bletch', 'xyzzy', 1234]
+   >>> # Clear the list: replace all items with an empty list
+   >>> a[:] = []
+   >>> a
+   []
+
+The built-in function :func:`len` also applies to lists::
+
+   >>> len(a)
+   8
+
+It is possible to nest lists (create lists containing other lists), for
+example::
+
+   >>> q = [2, 3]
+   >>> p = [1, q, 4]
+   >>> len(p)
+   3
+   >>> p[1]
+   [2, 3]
+   >>> p[1][0]
+   2
+   >>> p[1].append('xtra')     # See section 5.1
+   >>> p
+   [1, [2, 3, 'xtra'], 4]
+   >>> q
+   [2, 3, 'xtra']
+
+Note that in the last example, ``p[1]`` and ``q`` really refer to the same
+object!  We'll come back to *object semantics* later.
+
+
+.. _tut-firststeps:
+
+First Steps Towards Programming
+===============================
+
+Of course, we can use Python for more complicated tasks than adding two and two
+together.  For instance, we can write an initial sub-sequence of the *Fibonacci*
+series as follows::
+
+   >>> # Fibonacci series:
+   ... # the sum of two elements defines the next
+   ... a, b = 0, 1
+   >>> while b < 10:
+   ...       print b
+   ...       a, b = b, a+b
+   ... 
+   1
+   1
+   2
+   3
+   5
+   8
+
+This example introduces several new features.
+
+* The first line contains a *multiple assignment*: the variables ``a`` and ``b``
+  simultaneously get the new values 0 and 1.  On the last line this is used again,
+  demonstrating that the expressions on the right-hand side are all evaluated
+  first before any of the assignments take place.  The right-hand side expressions
+  are evaluated  from the left to the right.
+
+* The :keyword:`while` loop executes as long as the condition (here: ``b < 10``)
+  remains true.  In Python, like in C, any non-zero integer value is true; zero is
+  false.  The condition may also be a string or list value, in fact any sequence;
+  anything with a non-zero length is true, empty sequences are false.  The test
+  used in the example is a simple comparison.  The standard comparison operators
+  are written the same as in C: ``<`` (less than), ``>`` (greater than), ``==``
+  (equal to), ``<=`` (less than or equal to), ``>=`` (greater than or equal to)
+  and ``!=`` (not equal to).
+
+* The *body* of the loop is *indented*: indentation is Python's way of grouping
+  statements.  Python does not (yet!) provide an intelligent input line editing
+  facility, so you have to type a tab or space(s) for each indented line.  In
+  practice you will prepare more complicated input for Python with a text editor;
+  most text editors have an auto-indent facility.  When a compound statement is
+  entered interactively, it must be followed by a blank line to indicate
+  completion (since the parser cannot guess when you have typed the last line).
+  Note that each line within a basic block must be indented by the same amount.
+
+* The :keyword:`print` statement writes the value of the expression(s) it is
+  given.  It differs from just writing the expression you want to write (as we did
+  earlier in the calculator examples) in the way it handles multiple expressions
+  and strings.  Strings are printed without quotes, and a space is inserted
+  between items, so you can format things nicely, like this::
+
+     >>> i = 256*256
+     >>> print 'The value of i is', i
+     The value of i is 65536
+
+  A trailing comma avoids the newline after the output::
+
+     >>> a, b = 0, 1
+     >>> while b < 1000:
+     ...     print b,
+     ...     a, b = b, a+b
+     ... 
+     1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987
+
+  Note that the interpreter inserts a newline before it prints the next prompt if
+  the last line was not completed.
+
+
diff --git a/Doc/tutorial/modules.rst b/Doc/tutorial/modules.rst
new file mode 100644
index 0000000..0b0dabd
--- /dev/null
+++ b/Doc/tutorial/modules.rst
@@ -0,0 +1,551 @@
+.. _tut-modules:
+
+*******
+Modules
+*******
+
+If you quit from the Python interpreter and enter it again, the definitions you
+have made (functions and variables) are lost. Therefore, if you want to write a
+somewhat longer program, you are better off using a text editor to prepare the
+input for the interpreter and running it with that file as input instead.  This
+is known as creating a *script*.  As your program gets longer, you may want to
+split it into several files for easier maintenance.  You may also want to use a
+handy function that you've written in several programs without copying its
+definition into each program.
+
+To support this, Python has a way to put definitions in a file and use them in a
+script or in an interactive instance of the interpreter. Such a file is called a
+*module*; definitions from a module can be *imported* into other modules or into
+the *main* module (the collection of variables that you have access to in a
+script executed at the top level and in calculator mode).
+
+A module is a file containing Python definitions and statements.  The file name
+is the module name with the suffix :file:`.py` appended.  Within a module, the
+module's name (as a string) is available as the value of the global variable
+``__name__``.  For instance, use your favorite text editor to create a file
+called :file:`fibo.py` in the current directory with the following contents::
+
+   # Fibonacci numbers module
+
+   def fib(n):    # write Fibonacci series up to n
+       a, b = 0, 1
+       while b < n:
+           print b,
+           a, b = b, a+b
+
+   def fib2(n): # return Fibonacci series up to n
+       result = []
+       a, b = 0, 1
+       while b < n:
+           result.append(b)
+           a, b = b, a+b
+       return result
+
+Now enter the Python interpreter and import this module with the following
+command::
+
+   >>> import fibo
+
+This does not enter the names of the functions defined in ``fibo``  directly in
+the current symbol table; it only enters the module name ``fibo`` there. Using
+the module name you can access the functions::
+
+   >>> fibo.fib(1000)
+   1 1 2 3 5 8 13 21 34 55 89 144 233 377 610 987
+   >>> fibo.fib2(100)
+   [1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89]
+   >>> fibo.__name__
+   'fibo'
+
+If you intend to use a function often you can assign it to a local name::
+
+   >>> fib = fibo.fib
+   >>> fib(500)
+   1 1 2 3 5 8 13 21 34 55 89 144 233 377
+
+
+.. _tut-moremodules:
+
+More on Modules
+===============
+
+A module can contain executable statements as well as function definitions.
+These statements are intended to initialize the module. They are executed only
+the *first* time the module is imported somewhere. [#]_
+
+Each module has its own private symbol table, which is used as the global symbol
+table by all functions defined in the module. Thus, the author of a module can
+use global variables in the module without worrying about accidental clashes
+with a user's global variables. On the other hand, if you know what you are
+doing you can touch a module's global variables with the same notation used to
+refer to its functions, ``modname.itemname``.
+
+Modules can import other modules.  It is customary but not required to place all
+:keyword:`import` statements at the beginning of a module (or script, for that
+matter).  The imported module names are placed in the importing module's global
+symbol table.
+
+There is a variant of the :keyword:`import` statement that imports names from a
+module directly into the importing module's symbol table.  For example::
+
+   >>> from fibo import fib, fib2
+   >>> fib(500)
+   1 1 2 3 5 8 13 21 34 55 89 144 233 377
+
+This does not introduce the module name from which the imports are taken in the
+local symbol table (so in the example, ``fibo`` is not defined).
+
+There is even a variant to import all names that a module defines::
+
+   >>> from fibo import *
+   >>> fib(500)
+   1 1 2 3 5 8 13 21 34 55 89 144 233 377
+
+This imports all names except those beginning with an underscore (``_``).
+
+
+.. _tut-modulesasscripts:
+
+Executing modules as scripts
+----------------------------
+
+When you run a Python module with ::
+
+   python fibo.py <arguments>
+
+the code in the module will be executed, just as if you imported it, but with
+the ``__name__`` set to ``"__main__"``.  That means that by adding this code at
+the end of your module::
+
+   if __name__ == "__main__":
+       import sys
+       fib(int(sys.argv[1]))
+
+you can make the file usable as a script as well as an importable module,
+because the code that parses the command line only runs if the module is
+executed as the "main" file::
+
+   $ python fibo.py 50
+   1 1 2 3 5 8 13 21 34
+
+If the module is imported, the code is not run::
+
+   >>> import fibo
+   >>>
+
+This is often used either to provide a convenient user interface to a module, or
+for testing purposes (running the module as a script executes a test suite).
+
+
+.. _tut-searchpath:
+
+The Module Search Path
+----------------------
+
+.. index:: triple: module; search; path
+
+When a module named :mod:`spam` is imported, the interpreter searches for a file
+named :file:`spam.py` in the current directory, and then in the list of
+directories specified by the environment variable :envvar:`PYTHONPATH`.  This
+has the same syntax as the shell variable :envvar:`PATH`, that is, a list of
+directory names.  When :envvar:`PYTHONPATH` is not set, or when the file is not
+found there, the search continues in an installation-dependent default path; on
+Unix, this is usually :file:`.:/usr/local/lib/python`.
+
+Actually, modules are searched in the list of directories given by the variable
+``sys.path`` which is initialized from the directory containing the input script
+(or the current directory), :envvar:`PYTHONPATH` and the installation- dependent
+default.  This allows Python programs that know what they're doing to modify or
+replace the module search path.  Note that because the directory containing the
+script being run is on the search path, it is important that the script not have
+the same name as a standard module, or Python will attempt to load the script as
+a module when that module is imported. This will generally be an error.  See
+section :ref:`tut-standardmodules` for more information.
+
+
+"Compiled" Python files
+-----------------------
+
+As an important speed-up of the start-up time for short programs that use a lot
+of standard modules, if a file called :file:`spam.pyc` exists in the directory
+where :file:`spam.py` is found, this is assumed to contain an
+already-"byte-compiled" version of the module :mod:`spam`. The modification time
+of the version of :file:`spam.py` used to create :file:`spam.pyc` is recorded in
+:file:`spam.pyc`, and the :file:`.pyc` file is ignored if these don't match.
+
+Normally, you don't need to do anything to create the :file:`spam.pyc` file.
+Whenever :file:`spam.py` is successfully compiled, an attempt is made to write
+the compiled version to :file:`spam.pyc`.  It is not an error if this attempt
+fails; if for any reason the file is not written completely, the resulting
+:file:`spam.pyc` file will be recognized as invalid and thus ignored later.  The
+contents of the :file:`spam.pyc` file are platform independent, so a Python
+module directory can be shared by machines of different architectures.
+
+Some tips for experts:
+
+* When the Python interpreter is invoked with the :option:`-O` flag, optimized
+  code is generated and stored in :file:`.pyo` files.  The optimizer currently
+  doesn't help much; it only removes :keyword:`assert` statements.  When
+  :option:`-O` is used, *all* bytecode is optimized; ``.pyc`` files are ignored
+  and ``.py`` files are compiled to optimized bytecode.
+
+* Passing two :option:`-O` flags to the Python interpreter (:option:`-OO`) will
+  cause the bytecode compiler to perform optimizations that could in some rare
+  cases result in malfunctioning programs.  Currently only ``__doc__`` strings are
+  removed from the bytecode, resulting in more compact :file:`.pyo` files.  Since
+  some programs may rely on having these available, you should only use this
+  option if you know what you're doing.
+
+* A program doesn't run any faster when it is read from a :file:`.pyc` or
+  :file:`.pyo` file than when it is read from a :file:`.py` file; the only thing
+  that's faster about :file:`.pyc` or :file:`.pyo` files is the speed with which
+  they are loaded.
+
+* When a script is run by giving its name on the command line, the bytecode for
+  the script is never written to a :file:`.pyc` or :file:`.pyo` file.  Thus, the
+  startup time of a script may be reduced by moving most of its code to a module
+  and having a small bootstrap script that imports that module.  It is also
+  possible to name a :file:`.pyc` or :file:`.pyo` file directly on the command
+  line.
+
+* It is possible to have a file called :file:`spam.pyc` (or :file:`spam.pyo`
+  when :option:`-O` is used) without a file :file:`spam.py` for the same module.
+  This can be used to distribute a library of Python code in a form that is
+  moderately hard to reverse engineer.
+
+  .. index:: module: compileall
+
+* The module :mod:`compileall` can create :file:`.pyc` files (or :file:`.pyo`
+  files when :option:`-O` is used) for all modules in a directory.
+
+  .. % 
+
+
+.. _tut-standardmodules:
+
+Standard Modules
+================
+
+.. index:: module: sys
+
+Python comes with a library of standard modules, described in a separate
+document, the Python Library Reference ("Library Reference" hereafter).  Some
+modules are built into the interpreter; these provide access to operations that
+are not part of the core of the language but are nevertheless built in, either
+for efficiency or to provide access to operating system primitives such as
+system calls.  The set of such modules is a configuration option which also
+depends on the underlying platform For example, the :mod:`winreg` module is only
+provided on Windows systems. One particular module deserves some attention:
+:mod:`sys`, which is built into every Python interpreter.  The variables
+``sys.ps1`` and ``sys.ps2`` define the strings used as primary and secondary
+prompts:
+
+.. % 
+
+::
+
+   >>> import sys
+   >>> sys.ps1
+   '>>> '
+   >>> sys.ps2
+   '... '
+   >>> sys.ps1 = 'C> '
+   C> print 'Yuck!'
+   Yuck!
+   C>
+
+
+These two variables are only defined if the interpreter is in interactive mode.
+
+The variable ``sys.path`` is a list of strings that determines the interpreter's
+search path for modules. It is initialized to a default path taken from the
+environment variable :envvar:`PYTHONPATH`, or from a built-in default if
+:envvar:`PYTHONPATH` is not set.  You can modify it using standard list
+operations::
+
+   >>> import sys
+   >>> sys.path.append('/ufs/guido/lib/python')
+
+
+.. _tut-dir:
+
+The :func:`dir` Function
+========================
+
+The built-in function :func:`dir` is used to find out which names a module
+defines.  It returns a sorted list of strings::
+
+   >>> import fibo, sys
+   >>> dir(fibo)
+   ['__name__', 'fib', 'fib2']
+   >>> dir(sys)
+   ['__displayhook__', '__doc__', '__excepthook__', '__name__', '__stderr__',
+    '__stdin__', '__stdout__', '_getframe', 'api_version', 'argv', 
+    'builtin_module_names', 'byteorder', 'callstats', 'copyright',
+    'displayhook', 'exc_info', 'excepthook',
+    'exec_prefix', 'executable', 'exit', 'getdefaultencoding', 'getdlopenflags',
+    'getrecursionlimit', 'getrefcount', 'hexversion', 'maxint', 'maxunicode',
+    'meta_path', 'modules', 'path', 'path_hooks', 'path_importer_cache',
+    'platform', 'prefix', 'ps1', 'ps2', 'setcheckinterval', 'setdlopenflags',
+    'setprofile', 'setrecursionlimit', 'settrace', 'stderr', 'stdin', 'stdout',
+    'version', 'version_info', 'warnoptions']
+
+Without arguments, :func:`dir` lists the names you have defined currently::
+
+   >>> a = [1, 2, 3, 4, 5]
+   >>> import fibo
+   >>> fib = fibo.fib
+   >>> dir()
+   ['__builtins__', '__doc__', '__file__', '__name__', 'a', 'fib', 'fibo', 'sys']
+
+Note that it lists all types of names: variables, modules, functions, etc.
+
+.. index:: module: __builtin__
+
+:func:`dir` does not list the names of built-in functions and variables.  If you
+want a list of those, they are defined in the standard module
+:mod:`__builtin__`::
+
+   >>> import __builtin__
+   >>> dir(__builtin__)
+   ['ArithmeticError', 'AssertionError', 'AttributeError', 'DeprecationWarning',
+    'EOFError', 'Ellipsis', 'EnvironmentError', 'Exception', 'False',
+    'FloatingPointError', 'FutureWarning', 'IOError', 'ImportError',
+    'IndentationError', 'IndexError', 'KeyError', 'KeyboardInterrupt',
+    'LookupError', 'MemoryError', 'NameError', 'None', 'NotImplemented',
+    'NotImplementedError', 'OSError', 'OverflowError', 
+    'PendingDeprecationWarning', 'ReferenceError', 'RuntimeError',
+    'RuntimeWarning', 'StopIteration', 'SyntaxError',
+    'SyntaxWarning', 'SystemError', 'SystemExit', 'TabError', 'True',
+    'TypeError', 'UnboundLocalError', 'UnicodeDecodeError',
+    'UnicodeEncodeError', 'UnicodeError', 'UnicodeTranslateError',
+    'UserWarning', 'ValueError', 'Warning', 'WindowsError',
+    'ZeroDivisionError', '_', '__debug__', '__doc__', '__import__',
+    '__name__', 'abs', 'basestring', 'bool', 'buffer',
+    'chr', 'classmethod', 'cmp', 'compile',
+    'complex', 'copyright', 'credits', 'delattr', 'dict', 'dir', 'divmod',
+    'enumerate', 'eval', 'exec', 'exit', 'filter', 'float',
+    'frozenset', 'getattr', 'globals', 'hasattr', 'hash', 'help', 'hex',
+    'id', 'input', 'int', 'isinstance', 'issubclass', 'iter',
+    'len', 'license', 'list', 'locals', 'map', 'max', 'min',
+    'object', 'oct', 'open', 'ord', 'pow', 'property', 'quit', 'range',
+    'repr', 'reversed', 'round', 'set',
+    'setattr', 'slice', 'sorted', 'staticmethod', 'str', 'sum', 'super',
+    'tuple', 'type', 'vars', 'zip']
+
+
+.. _tut-packages:
+
+Packages
+========
+
+Packages are a way of structuring Python's module namespace by using "dotted
+module names".  For example, the module name :mod:`A.B` designates a submodule
+named ``B`` in a package named ``A``.  Just like the use of modules saves the
+authors of different modules from having to worry about each other's global
+variable names, the use of dotted module names saves the authors of multi-module
+packages like NumPy or the Python Imaging Library from having to worry about
+each other's module names.
+
+Suppose you want to design a collection of modules (a "package") for the uniform
+handling of sound files and sound data.  There are many different sound file
+formats (usually recognized by their extension, for example: :file:`.wav`,
+:file:`.aiff`, :file:`.au`), so you may need to create and maintain a growing
+collection of modules for the conversion between the various file formats.
+There are also many different operations you might want to perform on sound data
+(such as mixing, adding echo, applying an equalizer function, creating an
+artificial stereo effect), so in addition you will be writing a never-ending
+stream of modules to perform these operations.  Here's a possible structure for
+your package (expressed in terms of a hierarchical filesystem)::
+
+   sound/                          Top-level package
+         __init__.py               Initialize the sound package
+         formats/                  Subpackage for file format conversions
+                 __init__.py
+                 wavread.py
+                 wavwrite.py
+                 aiffread.py
+                 aiffwrite.py
+                 auread.py
+                 auwrite.py
+                 ...
+         effects/                  Subpackage for sound effects
+                 __init__.py
+                 echo.py
+                 surround.py
+                 reverse.py
+                 ...
+         filters/                  Subpackage for filters
+                 __init__.py
+                 equalizer.py
+                 vocoder.py
+                 karaoke.py
+                 ...
+
+When importing the package, Python searches through the directories on
+``sys.path`` looking for the package subdirectory.
+
+The :file:`__init__.py` files are required to make Python treat the directories
+as containing packages; this is done to prevent directories with a common name,
+such as ``string``, from unintentionally hiding valid modules that occur later
+on the module search path. In the simplest case, :file:`__init__.py` can just be
+an empty file, but it can also execute initialization code for the package or
+set the ``__all__`` variable, described later.
+
+Users of the package can import individual modules from the package, for
+example::
+
+   import sound.effects.echo
+
+This loads the submodule :mod:`sound.effects.echo`.  It must be referenced with
+its full name. ::
+
+   sound.effects.echo.echofilter(input, output, delay=0.7, atten=4)
+
+An alternative way of importing the submodule is::
+
+   from sound.effects import echo
+
+This also loads the submodule :mod:`echo`, and makes it available without its
+package prefix, so it can be used as follows::
+
+   echo.echofilter(input, output, delay=0.7, atten=4)
+
+Yet another variation is to import the desired function or variable directly::
+
+   from sound.effects.echo import echofilter
+
+Again, this loads the submodule :mod:`echo`, but this makes its function
+:func:`echofilter` directly available::
+
+   echofilter(input, output, delay=0.7, atten=4)
+
+Note that when using ``from package import item``, the item can be either a
+submodule (or subpackage) of the package, or some  other name defined in the
+package, like a function, class or variable.  The ``import`` statement first
+tests whether the item is defined in the package; if not, it assumes it is a
+module and attempts to load it.  If it fails to find it, an :exc:`ImportError`
+exception is raised.
+
+Contrarily, when using syntax like ``import item.subitem.subsubitem``, each item
+except for the last must be a package; the last item can be a module or a
+package but can't be a class or function or variable defined in the previous
+item.
+
+
+.. _tut-pkg-import-star:
+
+Importing \* From a Package
+---------------------------
+
+.. index:: single: __all__
+
+Now what happens when the user writes ``from sound.effects import *``?  Ideally,
+one would hope that this somehow goes out to the filesystem, finds which
+submodules are present in the package, and imports them all.  Unfortunately,
+this operation does not work very well on Windows platforms, where the
+filesystem does not always have accurate information about the case of a
+filename!  On these platforms, there is no guaranteed way to know whether a file
+:file:`ECHO.PY` should be imported as a module :mod:`echo`, :mod:`Echo` or
+:mod:`ECHO`.  (For example, Windows 95 has the annoying practice of showing all
+file names with a capitalized first letter.)  The DOS 8+3 filename restriction
+adds another interesting problem for long module names.
+
+.. % The \code{__all__} Attribute
+
+The only solution is for the package author to provide an explicit index of the
+package.  The import statement uses the following convention: if a package's
+:file:`__init__.py` code defines a list named ``__all__``, it is taken to be the
+list of module names that should be imported when ``from package import *`` is
+encountered.  It is up to the package author to keep this list up-to-date when a
+new version of the package is released.  Package authors may also decide not to
+support it, if they don't see a use for importing \* from their package.  For
+example, the file :file:`sounds/effects/__init__.py` could contain the following
+code::
+
+   __all__ = ["echo", "surround", "reverse"]
+
+This would mean that ``from sound.effects import *`` would import the three
+named submodules of the :mod:`sound` package.
+
+If ``__all__`` is not defined, the statement ``from sound.effects import *``
+does *not* import all submodules from the package :mod:`sound.effects` into the
+current namespace; it only ensures that the package :mod:`sound.effects` has
+been imported (possibly running any initialization code in :file:`__init__.py`)
+and then imports whatever names are defined in the package.  This includes any
+names defined (and submodules explicitly loaded) by :file:`__init__.py`.  It
+also includes any submodules of the package that were explicitly loaded by
+previous import statements.  Consider this code::
+
+   import sound.effects.echo
+   import sound.effects.surround
+   from sound.effects import *
+
+In this example, the echo and surround modules are imported in the current
+namespace because they are defined in the :mod:`sound.effects` package when the
+``from...import`` statement is executed.  (This also works when ``__all__`` is
+defined.)
+
+Note that in general the practice of importing ``*`` from a module or package is
+frowned upon, since it often causes poorly readable code. However, it is okay to
+use it to save typing in interactive sessions, and certain modules are designed
+to export only names that follow certain patterns.
+
+Remember, there is nothing wrong with using ``from Package import
+specific_submodule``!  In fact, this is the recommended notation unless the
+importing module needs to use submodules with the same name from different
+packages.
+
+
+Intra-package References
+------------------------
+
+The submodules often need to refer to each other.  For example, the
+:mod:`surround` module might use the :mod:`echo` module.  In fact, such
+references are so common that the :keyword:`import` statement first looks in the
+containing package before looking in the standard module search path. Thus, the
+:mod:`surround` module can simply use ``import echo`` or ``from echo import
+echofilter``.  If the imported module is not found in the current package (the
+package of which the current module is a submodule), the :keyword:`import`
+statement looks for a top-level module with the given name.
+
+When packages are structured into subpackages (as with the :mod:`sound` package
+in the example), you can use absolute imports to refer to submodules of siblings
+packages.  For example, if the module :mod:`sound.filters.vocoder` needs to use
+the :mod:`echo` module in the :mod:`sound.effects` package, it can use ``from
+sound.effects import echo``.
+
+Starting with Python 2.5, in addition to the implicit relative imports described
+above, you can write explicit relative imports with the ``from module import
+name`` form of import statement. These explicit relative imports use leading
+dots to indicate the current and parent packages involved in the relative
+import. From the :mod:`surround` module for example, you might use::
+
+   from . import echo
+   from .. import formats
+   from ..filters import equalizer
+
+Note that both explicit and implicit relative imports are based on the name of
+the current module. Since the name of the main module is always ``"__main__"``,
+modules intended for use as the main module of a Python application should
+always use absolute imports.
+
+
+Packages in Multiple Directories
+--------------------------------
+
+Packages support one more special attribute, :attr:`__path__`.  This is
+initialized to be a list containing the name of the directory holding the
+package's :file:`__init__.py` before the code in that file is executed.  This
+variable can be modified; doing so affects future searches for modules and
+subpackages contained in the package.
+
+While this feature is not often needed, it can be used to extend the set of
+modules found in a package.
+
+
+.. rubric:: Footnotes
+
+.. [#] In fact function definitions are also 'statements' that are 'executed'; the
+   execution enters the function name in the module's global symbol table.
+
diff --git a/Doc/tutorial/stdlib.rst b/Doc/tutorial/stdlib.rst
new file mode 100644
index 0000000..7bbc5ef
--- /dev/null
+++ b/Doc/tutorial/stdlib.rst
@@ -0,0 +1,313 @@
+.. _tut-brieftour:
+
+**********************************
+Brief Tour of the Standard Library
+**********************************
+
+
+.. _tut-os-interface:
+
+Operating System Interface
+==========================
+
+The :mod:`os` module provides dozens of functions for interacting with the
+operating system::
+
+   >>> import os
+   >>> os.system('time 0:02')
+   0
+   >>> os.getcwd()      # Return the current working directory
+   'C:\\Python30'
+   >>> os.chdir('/server/accesslogs')
+
+Be sure to use the ``import os`` style instead of ``from os import *``.  This
+will keep :func:`os.open` from shadowing the builtin :func:`open` function which
+operates much differently.
+
+.. index:: builtin: help
+
+The builtin :func:`dir` and :func:`help` functions are useful as interactive
+aids for working with large modules like :mod:`os`::
+
+   >>> import os
+   >>> dir(os)
+   <returns a list of all module functions>
+   >>> help(os)
+   <returns an extensive manual page created from the module's docstrings>
+
+For daily file and directory management tasks, the :mod:`shutil` module provides
+a higher level interface that is easier to use::
+
+   >>> import shutil
+   >>> shutil.copyfile('data.db', 'archive.db')
+   >>> shutil.move('/build/executables', 'installdir')
+
+
+.. _tut-file-wildcards:
+
+File Wildcards
+==============
+
+The :mod:`glob` module provides a function for making file lists from directory
+wildcard searches::
+
+   >>> import glob
+   >>> glob.glob('*.py')
+   ['primes.py', 'random.py', 'quote.py']
+
+
+.. _tut-command-line-arguments:
+
+Command Line Arguments
+======================
+
+Common utility scripts often need to process command line arguments. These
+arguments are stored in the :mod:`sys` module's *argv* attribute as a list.  For
+instance the following output results from running ``python demo.py one two
+three`` at the command line::
+
+   >>> import sys
+   >>> print sys.argv
+   ['demo.py', 'one', 'two', 'three']
+
+The :mod:`getopt` module processes *sys.argv* using the conventions of the Unix
+:func:`getopt` function.  More powerful and flexible command line processing is
+provided by the :mod:`optparse` module.
+
+
+.. _tut-stderr:
+
+Error Output Redirection and Program Termination
+================================================
+
+The :mod:`sys` module also has attributes for *stdin*, *stdout*, and *stderr*.
+The latter is useful for emitting warnings and error messages to make them
+visible even when *stdout* has been redirected::
+
+   >>> sys.stderr.write('Warning, log file not found starting a new one\n')
+   Warning, log file not found starting a new one
+
+The most direct way to terminate a script is to use ``sys.exit()``.
+
+
+.. _tut-string-pattern-matching:
+
+String Pattern Matching
+=======================
+
+The :mod:`re` module provides regular expression tools for advanced string
+processing. For complex matching and manipulation, regular expressions offer
+succinct, optimized solutions::
+
+   >>> import re
+   >>> re.findall(r'\bf[a-z]*', 'which foot or hand fell fastest')
+   ['foot', 'fell', 'fastest']
+   >>> re.sub(r'(\b[a-z]+) \1', r'\1', 'cat in the the hat')
+   'cat in the hat'
+
+When only simple capabilities are needed, string methods are preferred because
+they are easier to read and debug::
+
+   >>> 'tea for too'.replace('too', 'two')
+   'tea for two'
+
+
+.. _tut-mathematics:
+
+Mathematics
+===========
+
+The :mod:`math` module gives access to the underlying C library functions for
+floating point math::
+
+   >>> import math
+   >>> math.cos(math.pi / 4.0)
+   0.70710678118654757
+   >>> math.log(1024, 2)
+   10.0
+
+The :mod:`random` module provides tools for making random selections::
+
+   >>> import random
+   >>> random.choice(['apple', 'pear', 'banana'])
+   'apple'
+   >>> random.sample(range(100), 10)   # sampling without replacement
+   [30, 83, 16, 4, 8, 81, 41, 50, 18, 33]
+   >>> random.random()    # random float
+   0.17970987693706186
+   >>> random.randrange(6)    # random integer chosen from range(6)
+   4   
+
+
+.. _tut-internet-access:
+
+Internet Access
+===============
+
+There are a number of modules for accessing the internet and processing internet
+protocols. Two of the simplest are :mod:`urllib2` for retrieving data from urls
+and :mod:`smtplib` for sending mail::
+
+   >>> import urllib2
+   >>> for line in urllib2.urlopen('http://tycho.usno.navy.mil/cgi-bin/timer.pl'):
+   ...     if 'EST' in line or 'EDT' in line:  # look for Eastern Time
+   ...         print line
+
+   <BR>Nov. 25, 09:43:32 PM EST
+
+   >>> import smtplib
+   >>> server = smtplib.SMTP('localhost')
+   >>> server.sendmail('soothsayer@example.org', 'jcaesar@example.org',
+   """To: jcaesar@example.org
+   From: soothsayer@example.org
+
+   Beware the Ides of March.
+   """)
+   >>> server.quit()
+
+
+.. _tut-dates-and-times:
+
+Dates and Times
+===============
+
+The :mod:`datetime` module supplies classes for manipulating dates and times in
+both simple and complex ways. While date and time arithmetic is supported, the
+focus of the implementation is on efficient member extraction for output
+formatting and manipulation.  The module also supports objects that are timezone
+aware. ::
+
+   # dates are easily constructed and formatted
+   >>> from datetime import date
+   >>> now = date.today()
+   >>> now
+   datetime.date(2003, 12, 2)
+   >>> now.strftime("%m-%d-%y. %d %b %Y is a %A on the %d day of %B.")
+   '12-02-03. 02 Dec 2003 is a Tuesday on the 02 day of December.'
+
+   # dates support calendar arithmetic
+   >>> birthday = date(1964, 7, 31)
+   >>> age = now - birthday
+   >>> age.days
+   14368
+
+
+.. _tut-data-compression:
+
+Data Compression
+================
+
+Common data archiving and compression formats are directly supported by modules
+including: :mod:`zlib`, :mod:`gzip`, :mod:`bz2`, :mod:`zipfile` and
+:mod:`tarfile`. ::
+
+   >>> import zlib
+   >>> s = 'witch which has which witches wrist watch'
+   >>> len(s)
+   41
+   >>> t = zlib.compress(s)
+   >>> len(t)
+   37
+   >>> zlib.decompress(t)
+   'witch which has which witches wrist watch'
+   >>> zlib.crc32(s)
+   226805979
+
+
+.. _tut-performance-measurement:
+
+Performance Measurement
+=======================
+
+Some Python users develop a deep interest in knowing the relative performance of
+different approaches to the same problem. Python provides a measurement tool
+that answers those questions immediately.
+
+For example, it may be tempting to use the tuple packing and unpacking feature
+instead of the traditional approach to swapping arguments. The :mod:`timeit`
+module quickly demonstrates a modest performance advantage::
+
+   >>> from timeit import Timer
+   >>> Timer('t=a; a=b; b=t', 'a=1; b=2').timeit()
+   0.57535828626024577
+   >>> Timer('a,b = b,a', 'a=1; b=2').timeit()
+   0.54962537085770791
+
+In contrast to :mod:`timeit`'s fine level of granularity, the :mod:`profile` and
+:mod:`pstats` modules provide tools for identifying time critical sections in
+larger blocks of code.
+
+
+.. _tut-quality-control:
+
+Quality Control
+===============
+
+One approach for developing high quality software is to write tests for each
+function as it is developed and to run those tests frequently during the
+development process.
+
+The :mod:`doctest` module provides a tool for scanning a module and validating
+tests embedded in a program's docstrings.  Test construction is as simple as
+cutting-and-pasting a typical call along with its results into the docstring.
+This improves the documentation by providing the user with an example and it
+allows the doctest module to make sure the code remains true to the
+documentation::
+
+   def average(values):
+       """Computes the arithmetic mean of a list of numbers.
+
+       >>> print average([20, 30, 70])
+       40.0
+       """
+       return sum(values, 0.0) / len(values)
+
+   import doctest
+   doctest.testmod()   # automatically validate the embedded tests
+
+The :mod:`unittest` module is not as effortless as the :mod:`doctest` module,
+but it allows a more comprehensive set of tests to be maintained in a separate
+file::
+
+   import unittest
+
+   class TestStatisticalFunctions(unittest.TestCase):
+
+       def test_average(self):
+           self.assertEqual(average([20, 30, 70]), 40.0)
+           self.assertEqual(round(average([1, 5, 7]), 1), 4.3)
+           self.assertRaises(ZeroDivisionError, average, [])
+           self.assertRaises(TypeError, average, 20, 30, 70)
+
+   unittest.main() # Calling from the command line invokes all tests
+
+
+.. _tut-batteries-included:
+
+Batteries Included
+==================
+
+Python has a "batteries included" philosophy.  This is best seen through the
+sophisticated and robust capabilities of its larger packages. For example:
+
+* The :mod:`xmlrpclib` and :mod:`SimpleXMLRPCServer` modules make implementing
+  remote procedure calls into an almost trivial task.  Despite the modules
+  names, no direct knowledge or handling of XML is needed.
+
+* The :mod:`email` package is a library for managing email messages, including
+  MIME and other RFC 2822-based message documents. Unlike :mod:`smtplib` and
+  :mod:`poplib` which actually send and receive messages, the email package has
+  a complete toolset for building or decoding complex message structures
+  (including attachments) and for implementing internet encoding and header
+  protocols.
+
+* The :mod:`xml.dom` and :mod:`xml.sax` packages provide robust support for
+  parsing this popular data interchange format. Likewise, the :mod:`csv` module
+  supports direct reads and writes in a common database format. Together, these
+  modules and packages greatly simplify data interchange between python
+  applications and other tools.
+
+* Internationalization is supported by a number of modules including
+  :mod:`gettext`, :mod:`locale`, and the :mod:`codecs` package.
+
+
diff --git a/Doc/tutorial/stdlib2.rst b/Doc/tutorial/stdlib2.rst
new file mode 100644
index 0000000..0ce2757
--- /dev/null
+++ b/Doc/tutorial/stdlib2.rst
@@ -0,0 +1,394 @@
+.. _tut-brieftourtwo:
+
+*********************************************
+Brief Tour of the Standard Library -- Part II
+*********************************************
+
+This second tour covers more advanced modules that support professional
+programming needs.  These modules rarely occur in small scripts.
+
+
+.. _tut-output-formatting:
+
+Output Formatting
+=================
+
+The :mod:`repr` module provides a version of :func:`repr` customized for
+abbreviated displays of large or deeply nested containers::
+
+   >>> import repr   
+   >>> repr.repr(set('supercalifragilisticexpialidocious'))
+   "set(['a', 'c', 'd', 'e', 'f', 'g', ...])"
+
+The :mod:`pprint` module offers more sophisticated control over printing both
+built-in and user defined objects in a way that is readable by the interpreter.
+When the result is longer than one line, the "pretty printer" adds line breaks
+and indentation to more clearly reveal data structure::
+
+   >>> import pprint
+   >>> t = [[[['black', 'cyan'], 'white', ['green', 'red']], [['magenta',
+   ...     'yellow'], 'blue']]]
+   ...
+   >>> pprint.pprint(t, width=30)
+   [[[['black', 'cyan'],
+      'white',
+      ['green', 'red']],
+     [['magenta', 'yellow'],
+      'blue']]]
+
+The :mod:`textwrap` module formats paragraphs of text to fit a given screen
+width::
+
+   >>> import textwrap
+   >>> doc = """The wrap() method is just like fill() except that it returns
+   ... a list of strings instead of one big string with newlines to separate
+   ... the wrapped lines."""
+   ...
+   >>> print textwrap.fill(doc, width=40)
+   The wrap() method is just like fill()
+   except that it returns a list of strings
+   instead of one big string with newlines
+   to separate the wrapped lines.
+
+The :mod:`locale` module accesses a database of culture specific data formats.
+The grouping attribute of locale's format function provides a direct way of
+formatting numbers with group separators::
+
+   >>> import locale
+   >>> locale.setlocale(locale.LC_ALL, 'English_United States.1252')
+   'English_United States.1252'
+   >>> conv = locale.localeconv()          # get a mapping of conventions
+   >>> x = 1234567.8
+   >>> locale.format("%d", x, grouping=True)
+   '1,234,567'
+   >>> locale.format("%s%.*f", (conv['currency_symbol'],
+   ...	      conv['frac_digits'], x), grouping=True)
+   '$1,234,567.80'
+
+
+.. _tut-templating:
+
+Templating
+==========
+
+The :mod:`string` module includes a versatile :class:`Template` class with a
+simplified syntax suitable for editing by end-users.  This allows users to
+customize their applications without having to alter the application.
+
+The format uses placeholder names formed by ``$`` with valid Python identifiers
+(alphanumeric characters and underscores).  Surrounding the placeholder with
+braces allows it to be followed by more alphanumeric letters with no intervening
+spaces.  Writing ``$$`` creates a single escaped ``$``::
+
+   >>> from string import Template
+   >>> t = Template('${village}folk send $$10 to $cause.')
+   >>> t.substitute(village='Nottingham', cause='the ditch fund')
+   'Nottinghamfolk send $10 to the ditch fund.'
+
+The :meth:`substitute` method raises a :exc:`KeyError` when a placeholder is not
+supplied in a dictionary or a keyword argument. For mail-merge style
+applications, user supplied data may be incomplete and the
+:meth:`safe_substitute` method may be more appropriate --- it will leave
+placeholders unchanged if data is missing::
+
+   >>> t = Template('Return the $item to $owner.')
+   >>> d = dict(item='unladen swallow')
+   >>> t.substitute(d)
+   Traceback (most recent call last):
+     . . .
+   KeyError: 'owner'
+   >>> t.safe_substitute(d)
+   'Return the unladen swallow to $owner.'
+
+Template subclasses can specify a custom delimiter.  For example, a batch
+renaming utility for a photo browser may elect to use percent signs for
+placeholders such as the current date, image sequence number, or file format::
+
+   >>> import time, os.path, sys
+   >>> def raw_input(prompt):
+   ...     sys.stdout.write(prompt)
+   ...     sys.stdout.flush()
+   ...     return sys.stdin.readline()
+   ... 
+   >>> photofiles = ['img_1074.jpg', 'img_1076.jpg', 'img_1077.jpg']
+   >>> class BatchRename(Template):
+   ...     delimiter = '%'
+   >>> fmt = raw_input('Enter rename style (%d-date %n-seqnum %f-format):  ')
+   Enter rename style (%d-date %n-seqnum %f-format):  Ashley_%n%f
+
+   >>> t = BatchRename(fmt)
+   >>> date = time.strftime('%d%b%y')
+   >>> for i, filename in enumerate(photofiles):
+   ...     base, ext = os.path.splitext(filename)
+   ...     newname = t.substitute(d=date, n=i, f=ext)
+   ...     print '%s --> %s' % (filename, newname)
+
+   img_1074.jpg --> Ashley_0.jpg
+   img_1076.jpg --> Ashley_1.jpg
+   img_1077.jpg --> Ashley_2.jpg
+
+Another application for templating is separating program logic from the details
+of multiple output formats.  This makes it possible to substitute custom
+templates for XML files, plain text reports, and HTML web reports.
+
+
+.. _tut-binary-formats:
+
+Working with Binary Data Record Layouts
+=======================================
+
+The :mod:`struct` module provides :func:`pack` and :func:`unpack` functions for
+working with variable length binary record formats.  The following example shows
+how to loop through header information in a ZIP file (with pack codes ``"H"``
+and ``"L"`` representing two and four byte unsigned numbers respectively)::
+
+   import struct
+
+   data = open('myfile.zip', 'rb').read()
+   start = 0
+   for i in range(3):                      # show the first 3 file headers
+       start += 14
+       fields = struct.unpack('LLLHH', data[start:start+16])
+       crc32, comp_size, uncomp_size, filenamesize, extra_size = fields
+
+       start += 16
+       filename = data[start:start+filenamesize]
+       start += filenamesize
+       extra = data[start:start+extra_size]
+       print filename, hex(crc32), comp_size, uncomp_size
+
+       start += extra_size + comp_size     # skip to the next header
+
+
+.. _tut-multi-threading:
+
+Multi-threading
+===============
+
+Threading is a technique for decoupling tasks which are not sequentially
+dependent.  Threads can be used to improve the responsiveness of applications
+that accept user input while other tasks run in the background.  A related use
+case is running I/O in parallel with computations in another thread.
+
+The following code shows how the high level :mod:`threading` module can run
+tasks in background while the main program continues to run::
+
+   import threading, zipfile
+
+   class AsyncZip(threading.Thread):
+       def __init__(self, infile, outfile):
+           threading.Thread.__init__(self)        
+           self.infile = infile
+           self.outfile = outfile
+       def run(self):
+           f = zipfile.ZipFile(self.outfile, 'w', zipfile.ZIP_DEFLATED)
+           f.write(self.infile)
+           f.close()
+           print 'Finished background zip of: ', self.infile
+
+   background = AsyncZip('mydata.txt', 'myarchive.zip')
+   background.start()
+   print 'The main program continues to run in foreground.'
+
+   background.join()    # Wait for the background task to finish
+   print 'Main program waited until background was done.'
+
+The principal challenge of multi-threaded applications is coordinating threads
+that share data or other resources.  To that end, the threading module provides
+a number of synchronization primitives including locks, events, condition
+variables, and semaphores.
+
+While those tools are powerful, minor design errors can result in problems that
+are difficult to reproduce.  So, the preferred approach to task coordination is
+to concentrate all access to a resource in a single thread and then use the
+:mod:`Queue` module to feed that thread with requests from other threads.
+Applications using :class:`Queue` objects for inter-thread communication and
+coordination are easier to design, more readable, and more reliable.
+
+
+.. _tut-logging:
+
+Logging
+=======
+
+The :mod:`logging` module offers a full featured and flexible logging system.
+At its simplest, log messages are sent to a file or to ``sys.stderr``::
+
+   import logging
+   logging.debug('Debugging information')
+   logging.info('Informational message')
+   logging.warning('Warning:config file %s not found', 'server.conf')
+   logging.error('Error occurred')
+   logging.critical('Critical error -- shutting down')
+
+This produces the following output::
+
+   WARNING:root:Warning:config file server.conf not found
+   ERROR:root:Error occurred
+   CRITICAL:root:Critical error -- shutting down
+
+By default, informational and debugging messages are suppressed and the output
+is sent to standard error.  Other output options include routing messages
+through email, datagrams, sockets, or to an HTTP Server.  New filters can select
+different routing based on message priority: :const:`DEBUG`, :const:`INFO`,
+:const:`WARNING`, :const:`ERROR`, and :const:`CRITICAL`.
+
+The logging system can be configured directly from Python or can be loaded from
+a user editable configuration file for customized logging without altering the
+application.
+
+
+.. _tut-weak-references:
+
+Weak References
+===============
+
+Python does automatic memory management (reference counting for most objects and
+garbage collection to eliminate cycles).  The memory is freed shortly after the
+last reference to it has been eliminated.
+
+This approach works fine for most applications but occasionally there is a need
+to track objects only as long as they are being used by something else.
+Unfortunately, just tracking them creates a reference that makes them permanent.
+The :mod:`weakref` module provides tools for tracking objects without creating a
+reference.  When the object is no longer needed, it is automatically removed
+from a weakref table and a callback is triggered for weakref objects.  Typical
+applications include caching objects that are expensive to create::
+
+   >>> import weakref, gc
+   >>> class A:
+   ...     def __init__(self, value):
+   ...             self.value = value
+   ...     def __repr__(self):
+   ...             return str(self.value)
+   ...
+   >>> a = A(10)                   # create a reference
+   >>> d = weakref.WeakValueDictionary()
+   >>> d['primary'] = a            # does not create a reference
+   >>> d['primary']                # fetch the object if it is still alive
+   10
+   >>> del a                       # remove the one reference
+   >>> gc.collect()                # run garbage collection right away
+   0
+   >>> d['primary']                # entry was automatically removed
+   Traceback (most recent call last):
+     File "<pyshell#108>", line 1, in -toplevel-
+       d['primary']                # entry was automatically removed
+     File "C:/python30/lib/weakref.py", line 46, in __getitem__
+       o = self.data[key]()
+   KeyError: 'primary'
+
+
+.. _tut-list-tools:
+
+Tools for Working with Lists
+============================
+
+Many data structure needs can be met with the built-in list type. However,
+sometimes there is a need for alternative implementations with different
+performance trade-offs.
+
+The :mod:`array` module provides an :class:`array()` object that is like a list
+that stores only homogenous data and stores it more compactly.  The following
+example shows an array of numbers stored as two byte unsigned binary numbers
+(typecode ``"H"``) rather than the usual 16 bytes per entry for regular lists of
+python int objects::
+
+   >>> from array import array
+   >>> a = array('H', [4000, 10, 700, 22222])
+   >>> sum(a)
+   26932
+   >>> a[1:3]
+   array('H', [10, 700])
+
+The :mod:`collections` module provides a :class:`deque()` object that is like a
+list with faster appends and pops from the left side but slower lookups in the
+middle. These objects are well suited for implementing queues and breadth first
+tree searches::
+
+   >>> from collections import deque
+   >>> d = deque(["task1", "task2", "task3"])
+   >>> d.append("task4")
+   >>> print "Handling", d.popleft()
+   Handling task1
+
+   unsearched = deque([starting_node])
+   def breadth_first_search(unsearched):
+       node = unsearched.popleft()
+       for m in gen_moves(node):
+           if is_goal(m):
+               return m
+           unsearched.append(m)
+
+In addition to alternative list implementations, the library also offers other
+tools such as the :mod:`bisect` module with functions for manipulating sorted
+lists::
+
+   >>> import bisect
+   >>> scores = [(100, 'perl'), (200, 'tcl'), (400, 'lua'), (500, 'python')]
+   >>> bisect.insort(scores, (300, 'ruby'))
+   >>> scores
+   [(100, 'perl'), (200, 'tcl'), (300, 'ruby'), (400, 'lua'), (500, 'python')]
+
+The :mod:`heapq` module provides functions for implementing heaps based on
+regular lists.  The lowest valued entry is always kept at position zero.  This
+is useful for applications which repeatedly access the smallest element but do
+not want to run a full list sort::
+
+   >>> from heapq import heapify, heappop, heappush
+   >>> data = [1, 3, 5, 7, 9, 2, 4, 6, 8, 0]
+   >>> heapify(data)                      # rearrange the list into heap order
+   >>> heappush(data, -5)                 # add a new entry
+   >>> [heappop(data) for i in range(3)]  # fetch the three smallest entries
+   [-5, 0, 1]
+
+
+.. _tut-decimal-fp:
+
+Decimal Floating Point Arithmetic
+=================================
+
+The :mod:`decimal` module offers a :class:`Decimal` datatype for decimal
+floating point arithmetic.  Compared to the built-in :class:`float`
+implementation of binary floating point, the new class is especially helpful for
+financial applications and other uses which require exact decimal
+representation, control over precision, control over rounding to meet legal or
+regulatory requirements, tracking of significant decimal places, or for
+applications where the user expects the results to match calculations done by
+hand.
+
+For example, calculating a 5% tax on a 70 cent phone charge gives different
+results in decimal floating point and binary floating point. The difference
+becomes significant if the results are rounded to the nearest cent::
+
+   >>> from decimal import *       
+   >>> Decimal('0.70') * Decimal('1.05')
+   Decimal("0.7350")
+   >>> .70 * 1.05
+   0.73499999999999999       
+
+The :class:`Decimal` result keeps a trailing zero, automatically inferring four
+place significance from multiplicands with two place significance.  Decimal
+reproduces mathematics as done by hand and avoids issues that can arise when
+binary floating point cannot exactly represent decimal quantities.
+
+Exact representation enables the :class:`Decimal` class to perform modulo
+calculations and equality tests that are unsuitable for binary floating point::
+
+   >>> Decimal('1.00') % Decimal('.10')
+   Decimal("0.00")
+   >>> 1.00 % 0.10
+   0.09999999999999995
+
+   >>> sum([Decimal('0.1')]*10) == Decimal('1.0')
+   True
+   >>> sum([0.1]*10) == 1.0
+   False      
+
+The :mod:`decimal` module provides arithmetic with as much precision as needed::
+
+   >>> getcontext().prec = 36
+   >>> Decimal(1) / Decimal(7)
+   Decimal("0.142857142857142857142857142857142857")
+
+
diff --git a/Doc/tutorial/whatnow.rst b/Doc/tutorial/whatnow.rst
new file mode 100644
index 0000000..599fcbd
--- /dev/null
+++ b/Doc/tutorial/whatnow.rst
@@ -0,0 +1,68 @@
+.. _tut-whatnow:
+
+*********
+What Now?
+*********
+
+Reading this tutorial has probably reinforced your interest in using Python ---
+you should be eager to apply Python to solving your real-world problems. Where
+should you go to learn more?
+
+This tutorial is part of Python's documentation set.   Some other documents in
+the set are:
+
+* :ref:`library-index`:
+
+  You should browse through this manual, which gives complete (though terse)
+  reference material about types, functions, and the modules in the standard
+  library.  The standard Python distribution includes a *lot* of additional code.
+  There are modules to read Unix mailboxes, retrieve documents via HTTP, generate
+  random numbers, parse command-line options, write CGI programs, compress data,
+  and many other tasks. Skimming through the Library Reference will give you an
+  idea of what's available.
+
+* :ref:`install-index` explains how to install external modules written by other
+  Python users.
+
+* :ref:`reference-index`: A detailed explanation of Python's syntax and
+  semantics.  It's heavy reading, but is useful as a complete guide to the
+  language itself.
+
+More Python resources:
+
+* http://www.python.org:  The major Python Web site.  It contains code,
+  documentation, and pointers to Python-related pages around the Web.  This Web
+  site is mirrored in various places around the world, such as Europe, Japan, and
+  Australia; a mirror may be faster than the main site, depending on your
+  geographical location.
+
+* http://docs.python.org:  Fast access to Python's  documentation.
+
+* http://cheeseshop.python.org:  The Python Package Index, nicknamed the Cheese
+  Shop,  is an index of user-created Python modules that are available for
+  download.  Once you begin releasing code, you can register it  here so that
+  others can find it.
+
+* http://aspn.activestate.com/ASPN/Python/Cookbook/: The Python Cookbook is a
+  sizable collection of code examples, larger modules, and useful scripts.
+  Particularly notable contributions are collected in a book also titled Python
+  Cookbook (O'Reilly & Associates, ISBN 0-596-00797-3.)
+
+For Python-related questions and problem reports, you can post to the newsgroup
+:newsgroup:`comp.lang.python`, or send them to the mailing list at
+python-list@python.org.  The newsgroup and mailing list are gatewayed, so
+messages posted to one will automatically be forwarded to the other.  There are
+around 120 postings a day (with peaks up to several hundred), asking (and
+answering) questions, suggesting new features, and announcing new modules.
+Before posting, be sure to check the list of `Frequently Asked Questions
+<http://www.python.org/doc/faq/>`_ (also called the FAQ), or look for it in the
+:file:`Misc/` directory of the Python source distribution.  Mailing list
+archives are available at http://mail.python.org/pipermail/. The FAQ answers
+many of the questions that come up again and again, and may already contain the
+solution for your problem.
+
+.. % Postings figure based on average of last six months activity as
+.. % reported by www.egroups.com; Jan. 2000 - June 2000: 21272 msgs / 182
+.. % days = 116.9 msgs / day and steadily increasing.
+
+
diff --git a/Doc/whatsnew/2.0.rst b/Doc/whatsnew/2.0.rst
new file mode 100644
index 0000000..302986c
--- /dev/null
+++ b/Doc/whatsnew/2.0.rst
@@ -0,0 +1,1207 @@
+****************************
+  What's New in Python 2.0  
+****************************
+
+:Author: A.M. Kuchling and Moshe Zadka
+
+.. |release| replace:: 1.02
+
+.. % $Id: whatsnew20.tex 51211 2006-08-11 14:57:12Z thomas.wouters $
+
+
+Introduction
+============
+
+A new release of Python, version 2.0, was released on October 16, 2000. This
+article covers the exciting new features in 2.0, highlights some other useful
+changes, and points out a few incompatible changes that may require rewriting
+code.
+
+Python's development never completely stops between releases, and a steady flow
+of bug fixes and improvements are always being submitted. A host of minor fixes,
+a few optimizations, additional docstrings, and better error messages went into
+2.0; to list them all would be impossible, but they're certainly significant.
+Consult the publicly-available CVS logs if you want to see the full list.  This
+progress is due to the five developers working for  PythonLabs are now getting
+paid to spend their days fixing bugs, and also due to the improved communication
+resulting  from moving to SourceForge.
+
+.. % ======================================================================
+
+
+What About Python 1.6?
+======================
+
+Python 1.6 can be thought of as the Contractual Obligations Python release.
+After the core development team left CNRI in May 2000, CNRI requested that a 1.6
+release be created, containing all the work on Python that had been performed at
+CNRI.  Python 1.6 therefore represents the state of the CVS tree as of May 2000,
+with the most significant new feature being Unicode support.  Development
+continued after May, of course, so the 1.6 tree received a few fixes to ensure
+that it's forward-compatible with Python 2.0.  1.6 is therefore part of Python's
+evolution, and not a side branch.
+
+So, should you take much interest in Python 1.6?  Probably not.  The 1.6final
+and 2.0beta1 releases were made on the same day (September 5, 2000), the plan
+being to finalize Python 2.0 within a month or so.  If you have applications to
+maintain, there seems little point in breaking things by moving to 1.6, fixing
+them, and then having another round of breakage within a month by moving to 2.0;
+you're better off just going straight to 2.0.  Most of the really interesting
+features described in this document are only in 2.0, because a lot of work was
+done between May and September.
+
+.. % ======================================================================
+
+
+New Development Process
+=======================
+
+The most important change in Python 2.0 may not be to the code at all, but to
+how Python is developed: in May 2000 the Python developers began using the tools
+made available by SourceForge for storing  source code, tracking bug reports,
+and managing the queue of patch submissions.  To report bugs or submit patches
+for Python 2.0, use the bug tracking and patch manager tools available from
+Python's project page, located at http://sourceforge.net/projects/python/.
+
+The most important of the services now hosted at SourceForge is the Python CVS
+tree, the version-controlled repository containing the source code for Python.
+Previously, there were roughly 7 or so people who had write access to the CVS
+tree, and all patches had to be inspected and checked in by one of the people on
+this short list. Obviously, this wasn't very scalable.  By moving the CVS tree
+to SourceForge, it became possible to grant write access to more people; as of
+September 2000 there were 27 people able to check in changes, a fourfold
+increase.  This makes possible large-scale changes that wouldn't be attempted if
+they'd have to be filtered through the small group of core developers.  For
+example, one day Peter Schneider-Kamp took it into his head to drop K&R C
+compatibility and convert the C source for Python to ANSI C. After getting
+approval on the python-dev mailing list, he launched into a flurry of checkins
+that lasted about a week, other developers joined in to help, and the job was
+done.  If there were only 5 people with write access, probably that task would
+have been viewed as "nice, but not worth the time and effort needed" and it
+would never have gotten done.
+
+The shift to using SourceForge's services has resulted in a remarkable increase
+in the speed of development.  Patches now get submitted, commented on, revised
+by people other than the original submitter, and bounced back and forth between
+people until the patch is deemed worth checking in.  Bugs are tracked in one
+central location and can be assigned to a specific person for fixing, and we can
+count the number of open bugs to measure progress.  This didn't come without a
+cost: developers now have more e-mail to deal with, more mailing lists to
+follow, and special tools had to be written for the new environment. For
+example, SourceForge sends default patch and bug notification e-mail messages
+that are completely unhelpful, so Ka-Ping Yee wrote an HTML screen-scraper that
+sends more useful messages.
+
+The ease of adding code caused a few initial growing pains, such as code was
+checked in before it was ready or without getting clear agreement from the
+developer group.  The approval process that has emerged is somewhat similar to
+that used by the Apache group. Developers can vote +1, +0, -0, or -1 on a patch;
++1 and -1 denote acceptance or rejection, while +0 and -0 mean the developer is
+mostly indifferent to the change, though with a slight positive or negative
+slant.  The most significant change from the Apache model is that the voting is
+essentially advisory, letting Guido van Rossum, who has Benevolent Dictator For
+Life status, know what the general opinion is. He can still ignore the result of
+a vote, and approve or reject a change even if the community disagrees with him.
+
+Producing an actual patch is the last step in adding a new feature, and is
+usually easy compared to the earlier task of coming up with a good design.
+Discussions of new features can often explode into lengthy mailing list threads,
+making the discussion hard to follow, and no one can read every posting to
+python-dev.  Therefore, a relatively formal process has been set up to write
+Python Enhancement Proposals (PEPs), modelled on the Internet RFC process.  PEPs
+are draft documents that describe a proposed new feature, and are continually
+revised until the community reaches a consensus, either accepting or rejecting
+the proposal.  Quoting from the introduction to PEP 1, "PEP Purpose and
+Guidelines":
+
+
+.. epigraph::
+
+   PEP stands for Python Enhancement Proposal.  A PEP is a design document
+   providing information to the Python community, or describing a new feature for
+   Python.  The PEP should provide a concise technical specification of the feature
+   and a rationale for the feature.
+
+   We intend PEPs to be the primary mechanisms for proposing new features, for
+   collecting community input on an issue, and for documenting the design decisions
+   that have gone into Python.  The PEP author is responsible for building
+   consensus within the community and documenting dissenting opinions.
+
+Read the rest of PEP 1 for the details of the PEP editorial process, style, and
+format.  PEPs are kept in the Python CVS tree on SourceForge, though they're not
+part of the Python 2.0 distribution, and are also available in HTML form from
+http://www.python.org/peps/.  As of September 2000, there are 25 PEPS, ranging
+from PEP 201, "Lockstep Iteration", to PEP 225, "Elementwise/Objectwise
+Operators".
+
+.. % ======================================================================
+
+
+Unicode
+=======
+
+The largest new feature in Python 2.0 is a new fundamental data type: Unicode
+strings.  Unicode uses 16-bit numbers to represent characters instead of the
+8-bit number used by ASCII, meaning that 65,536 distinct characters can be
+supported.
+
+The final interface for Unicode support was arrived at through countless often-
+stormy discussions on the python-dev mailing list, and mostly implemented by
+Marc-André Lemburg, based on a Unicode string type implementation by Fredrik
+Lundh.  A detailed explanation of the interface was written up as :pep:`100`,
+"Python Unicode Integration". This article will simply cover the most
+significant points about the Unicode interfaces.
+
+In Python source code, Unicode strings are written as ``u"string"``.  Arbitrary
+Unicode characters can be written using a new escape sequence, ``\uHHHH``, where
+*HHHH* is a 4-digit hexadecimal number from 0000 to FFFF.  The existing
+``\xHHHH`` escape sequence can also be used, and octal escapes can be used for
+characters up to U+01FF, which is represented by ``\777``.
+
+Unicode strings, just like regular strings, are an immutable sequence type.
+They can be indexed and sliced, but not modified in place. Unicode strings have
+an ``encode( [encoding] )`` method that returns an 8-bit string in the desired
+encoding.  Encodings are named by strings, such as ``'ascii'``, ``'utf-8'``,
+``'iso-8859-1'``, or whatever.  A codec API is defined for implementing and
+registering new encodings that are then available throughout a Python program.
+If an encoding isn't specified, the default encoding is usually 7-bit ASCII,
+though it can be changed for your Python installation by calling the
+:func:`sys.setdefaultencoding(encoding)` function in a customised version of
+:file:`site.py`.
+
+Combining 8-bit and Unicode strings always coerces to Unicode, using the default
+ASCII encoding; the result of ``'a' + u'bc'`` is ``u'abc'``.
+
+New built-in functions have been added, and existing built-ins modified to
+support Unicode:
+
+* ``unichr(ch)`` returns a Unicode string 1 character long, containing the
+  character *ch*.
+
+* ``ord(u)``, where *u* is a 1-character regular or Unicode string, returns the
+  number of the character as an integer.
+
+* ``unicode(string [, encoding]  [, errors] )`` creates a Unicode string
+  from an 8-bit string.  ``encoding`` is a string naming the encoding to use. The
+  ``errors`` parameter specifies the treatment of characters that are invalid for
+  the current encoding; passing ``'strict'`` as the value causes an exception to
+  be raised on any encoding error, while ``'ignore'`` causes errors to be silently
+  ignored and ``'replace'`` uses U+FFFD, the official replacement character, in
+  case of any problems.
+
+* The :keyword:`exec` statement, and various built-ins such as ``eval()``,
+  ``getattr()``, and ``setattr()`` will also accept Unicode strings as well as
+  regular strings.  (It's possible that the process of fixing this missed some
+  built-ins; if you find a built-in function that accepts strings but doesn't
+  accept Unicode strings at all, please report it as a bug.)
+
+A new module, :mod:`unicodedata`, provides an interface to Unicode character
+properties.  For example, ``unicodedata.category(u'A')`` returns the 2-character
+string 'Lu', the 'L' denoting it's a letter, and 'u' meaning that it's
+uppercase. ``unicodedata.bidirectional(u'\u0660')`` returns 'AN', meaning that
+U+0660 is an Arabic number.
+
+The :mod:`codecs` module contains functions to look up existing encodings and
+register new ones.  Unless you want to implement a new encoding, you'll most
+often use the :func:`codecs.lookup(encoding)` function, which returns a
+4-element tuple: ``(encode_func, decode_func, stream_reader, stream_writer)``.
+
+* *encode_func* is a function that takes a Unicode string, and returns a 2-tuple
+  ``(string, length)``.  *string* is an 8-bit string containing a portion (perhaps
+  all) of the Unicode string converted into the given encoding, and *length* tells
+  you how much of the Unicode string was converted.
+
+* *decode_func* is the opposite of *encode_func*, taking an 8-bit string and
+  returning a 2-tuple ``(ustring, length)``, consisting of the resulting Unicode
+  string *ustring* and the integer *length* telling how much of the 8-bit string
+  was consumed.
+
+* *stream_reader* is a class that supports decoding input from a stream.
+  *stream_reader(file_obj)* returns an object that supports the :meth:`read`,
+  :meth:`readline`, and :meth:`readlines` methods.  These methods will all
+  translate from the given encoding and return Unicode strings.
+
+* *stream_writer*, similarly, is a class that supports encoding output to a
+  stream.  *stream_writer(file_obj)* returns an object that supports the
+  :meth:`write` and :meth:`writelines` methods.  These methods expect Unicode
+  strings, translating them to the given encoding on output.
+
+For example, the following code writes a Unicode string into a file,  encoding
+it as UTF-8::
+
+   import codecs
+
+   unistr = u'\u0660\u2000ab ...'
+
+   (UTF8_encode, UTF8_decode,
+    UTF8_streamreader, UTF8_streamwriter) = codecs.lookup('UTF-8')
+
+   output = UTF8_streamwriter( open( '/tmp/output', 'wb') )
+   output.write( unistr )
+   output.close()
+
+The following code would then read UTF-8 input from the file::
+
+   input = UTF8_streamreader( open( '/tmp/output', 'rb') )
+   print repr(input.read())
+   input.close()
+
+Unicode-aware regular expressions are available through the :mod:`re` module,
+which has a new underlying implementation called SRE written by Fredrik Lundh of
+Secret Labs AB.
+
+A ``-U`` command line option was added which causes the Python compiler to
+interpret all string literals as Unicode string literals. This is intended to be
+used in testing and future-proofing your Python code, since some future version
+of Python may drop support for 8-bit strings and provide only Unicode strings.
+
+.. % ======================================================================
+
+
+List Comprehensions
+===================
+
+Lists are a workhorse data type in Python, and many programs manipulate a list
+at some point.  Two common operations on lists are to loop over them, and either
+pick out the elements that meet a certain criterion, or apply some function to
+each element.  For example, given a list of strings, you might want to pull out
+all the strings containing a given substring, or strip off trailing whitespace
+from each line.
+
+The existing :func:`map` and :func:`filter` functions can be used for this
+purpose, but they require a function as one of their arguments.  This is fine if
+there's an existing built-in function that can be passed directly, but if there
+isn't, you have to create a little function to do the required work, and
+Python's scoping rules make the result ugly if the little function needs
+additional information.  Take the first example in the previous paragraph,
+finding all the strings in the list containing a given substring.  You could
+write the following to do it::
+
+   # Given the list L, make a list of all strings 
+   # containing the substring S.
+   sublist = filter( lambda s, substring=S: 
+                        string.find(s, substring) != -1,
+   	          L)
+
+Because of Python's scoping rules, a default argument is used so that the
+anonymous function created by the :keyword:`lambda` statement knows what
+substring is being searched for.  List comprehensions make this cleaner::
+
+   sublist = [ s for s in L if string.find(s, S) != -1 ]
+
+List comprehensions have the form::
+
+   [ expression for expr in sequence1 
+                for expr2 in sequence2 ...
+   	     for exprN in sequenceN
+                if condition ]
+
+The :keyword:`for`...\ :keyword:`in` clauses contain the sequences to be
+iterated over.  The sequences do not have to be the same length, because they
+are *not* iterated over in parallel, but from left to right; this is explained
+more clearly in the following paragraphs.  The elements of the generated list
+will be the successive values of *expression*.  The final :keyword:`if` clause
+is optional; if present, *expression* is only evaluated and added to the result
+if *condition* is true.
+
+To make the semantics very clear, a list comprehension is equivalent to the
+following Python code::
+
+   for expr1 in sequence1:
+       for expr2 in sequence2:
+       ...
+           for exprN in sequenceN:
+                if (condition):
+                     # Append the value of 
+                     # the expression to the 
+                     # resulting list.
+
+This means that when there are multiple :keyword:`for`...\ :keyword:`in`
+clauses, the resulting list will be equal to the product of the lengths of all
+the sequences.  If you have two lists of length 3, the output list is 9 elements
+long::
+
+   seq1 = 'abc'
+   seq2 = (1,2,3)
+   >>> [ (x,y) for x in seq1 for y in seq2]
+   [('a', 1), ('a', 2), ('a', 3), ('b', 1), ('b', 2), ('b', 3), ('c', 1),
+   ('c', 2), ('c', 3)]
+
+To avoid introducing an ambiguity into Python's grammar, if *expression* is
+creating a tuple, it must be surrounded with parentheses.  The first list
+comprehension below is a syntax error, while the second one is correct::
+
+   # Syntax error
+   [ x,y for x in seq1 for y in seq2]
+   # Correct
+   [ (x,y) for x in seq1 for y in seq2]
+
+The idea of list comprehensions originally comes from the functional programming
+language Haskell (http://www.haskell.org).  Greg Ewing argued most effectively
+for adding them to Python and wrote the initial list comprehension patch, which
+was then discussed for a seemingly endless time on the python-dev mailing list
+and kept up-to-date by Skip Montanaro.
+
+.. % ======================================================================
+
+
+Augmented Assignment
+====================
+
+Augmented assignment operators, another long-requested feature, have been added
+to Python 2.0.  Augmented assignment operators include ``+=``, ``-=``, ``*=``,
+and so forth.  For example, the statement ``a += 2`` increments the value of the
+variable  ``a`` by 2, equivalent to the slightly lengthier ``a = a + 2``.
+
+The full list of supported assignment operators is ``+=``, ``-=``, ``*=``,
+``/=``, ``%=``, ``**=``, ``&=``, ``|=``, ``^=``, ``>>=``, and ``<<=``.  Python
+classes can override the augmented assignment operators by defining methods
+named :meth:`__iadd__`, :meth:`__isub__`, etc.  For example, the following
+:class:`Number` class stores a number and supports using += to create a new
+instance with an incremented value.
+
+.. % The empty groups below prevent conversion to guillemets.
+
+::
+
+   class Number:
+       def __init__(self, value):
+           self.value = value
+       def __iadd__(self, increment):
+   	return Number( self.value + increment)
+
+   n = Number(5)
+   n += 3
+   print n.value
+
+The :meth:`__iadd__` special method is called with the value of the increment,
+and should return a new instance with an appropriately modified value; this
+return value is bound as the new value of the variable on the left-hand side.
+
+Augmented assignment operators were first introduced in the C programming
+language, and most C-derived languages, such as :program:`awk`, C++, Java, Perl,
+and PHP also support them.  The augmented assignment patch was implemented by
+Thomas Wouters.
+
+.. % ======================================================================
+
+
+String Methods
+==============
+
+Until now string-manipulation functionality was in the :mod:`string` module,
+which was usually a front-end for the :mod:`strop` module written in C.  The
+addition of Unicode posed a difficulty for the :mod:`strop` module, because the
+functions would all need to be rewritten in order to accept either 8-bit or
+Unicode strings.  For functions such as :func:`string.replace`, which takes 3
+string arguments, that means eight possible permutations, and correspondingly
+complicated code.
+
+Instead, Python 2.0 pushes the problem onto the string type, making string
+manipulation functionality available through methods on both 8-bit strings and
+Unicode strings.   ::
+
+   >>> 'andrew'.capitalize()
+   'Andrew'
+   >>> 'hostname'.replace('os', 'linux')
+   'hlinuxtname'
+   >>> 'moshe'.find('sh')
+   2
+
+One thing that hasn't changed, a noteworthy April Fools' joke notwithstanding,
+is that Python strings are immutable. Thus, the string methods return new
+strings, and do not modify the string on which they operate.
+
+The old :mod:`string` module is still around for backwards compatibility, but it
+mostly acts as a front-end to the new string methods.
+
+Two methods which have no parallel in pre-2.0 versions, although they did exist
+in JPython for quite some time, are :meth:`startswith` and :meth:`endswith`.
+``s.startswith(t)`` is equivalent to ``s[:len(t)] == t``, while
+``s.endswith(t)`` is equivalent to ``s[-len(t):] == t``.
+
+One other method which deserves special mention is :meth:`join`.  The
+:meth:`join` method of a string receives one parameter, a sequence of strings,
+and is equivalent to the :func:`string.join` function from the old :mod:`string`
+module, with the arguments reversed. In other words, ``s.join(seq)`` is
+equivalent to the old ``string.join(seq, s)``.
+
+.. % ======================================================================
+
+
+Garbage Collection of Cycles
+============================
+
+The C implementation of Python uses reference counting to implement garbage
+collection.  Every Python object maintains a count of the number of references
+pointing to itself, and adjusts the count as references are created or
+destroyed.  Once the reference count reaches zero, the object is no longer
+accessible, since you need to have a reference to an object to access it, and if
+the count is zero, no references exist any longer.
+
+Reference counting has some pleasant properties: it's easy to understand and
+implement, and the resulting implementation is portable, fairly fast, and reacts
+well with other libraries that implement their own memory handling schemes.  The
+major problem with reference counting is that it sometimes doesn't realise that
+objects are no longer accessible, resulting in a memory leak.  This happens when
+there are cycles of references.
+
+Consider the simplest possible cycle,  a class instance which has a reference to
+itself::
+
+   instance = SomeClass()
+   instance.myself = instance
+
+After the above two lines of code have been executed, the reference count of
+``instance`` is 2; one reference is from the variable named ``'instance'``, and
+the other is from the ``myself`` attribute of the instance.
+
+If the next line of code is ``del instance``, what happens?  The reference count
+of ``instance`` is decreased by 1, so it has a reference count of 1; the
+reference in the ``myself`` attribute still exists.  Yet the instance is no
+longer accessible through Python code, and it could be deleted.  Several objects
+can participate in a cycle if they have references to each other, causing all of
+the objects to be leaked.
+
+Python 2.0 fixes this problem by periodically executing a cycle detection
+algorithm which looks for inaccessible cycles and deletes the objects involved.
+A new :mod:`gc` module provides functions to perform a garbage collection,
+obtain debugging statistics, and tuning the collector's parameters.
+
+Running the cycle detection algorithm takes some time, and therefore will result
+in some additional overhead.  It is hoped that after we've gotten experience
+with the cycle collection from using 2.0, Python 2.1 will be able to minimize
+the overhead with careful tuning.  It's not yet obvious how much performance is
+lost, because benchmarking this is tricky and depends crucially on how often the
+program creates and destroys objects.  The detection of cycles can be disabled
+when Python is compiled, if you can't afford even a tiny speed penalty or
+suspect that the cycle collection is buggy, by specifying the
+:option:`--without-cycle-gc` switch when running the :program:`configure`
+script.
+
+Several people tackled this problem and contributed to a solution.  An early
+implementation of the cycle detection approach was written by Toby Kelsey.  The
+current algorithm was suggested by Eric Tiedemann during a visit to CNRI, and
+Guido van Rossum and Neil Schemenauer wrote two different implementations, which
+were later integrated by Neil.  Lots of other people offered suggestions along
+the way; the March 2000 archives of the python-dev mailing list contain most of
+the relevant discussion, especially in the threads titled "Reference cycle
+collection for Python" and "Finalization again".
+
+.. % ======================================================================
+
+
+Other Core Changes
+==================
+
+Various minor changes have been made to Python's syntax and built-in functions.
+None of the changes are very far-reaching, but they're handy conveniences.
+
+
+Minor Language Changes
+----------------------
+
+A new syntax makes it more convenient to call a given function with a tuple of
+arguments and/or a dictionary of keyword arguments. In Python 1.5 and earlier,
+you'd use the :func:`apply` built-in function: ``apply(f, args, kw)`` calls the
+function :func:`f` with the argument tuple *args* and the keyword arguments in
+the dictionary *kw*.  :func:`apply`  is the same in 2.0, but thanks to a patch
+from Greg Ewing, ``f(*args, **kw)`` as a shorter and clearer way to achieve the
+same effect.  This syntax is symmetrical with the syntax for defining
+functions::
+
+   def f(*args, **kw):
+       # args is a tuple of positional args,
+       # kw is a dictionary of keyword args
+       ...
+
+The :keyword:`print` statement can now have its output directed to a file-like
+object by following the :keyword:`print` with  ``>> file``, similar to the
+redirection operator in Unix shells. Previously you'd either have to use the
+:meth:`write` method of the file-like object, which lacks the convenience and
+simplicity of :keyword:`print`, or you could assign a new value to
+``sys.stdout`` and then restore the old value.  For sending output to standard
+error, it's much easier to write this::
+
+   print >> sys.stderr, "Warning: action field not supplied"
+
+Modules can now be renamed on importing them, using the syntax ``import module
+as name`` or ``from module import name as othername``.  The patch was submitted
+by Thomas Wouters.
+
+A new format style is available when using the ``%`` operator; '%r' will insert
+the :func:`repr` of its argument.  This was also added from symmetry
+considerations, this time for symmetry with the existing '%s' format style,
+which inserts the :func:`str` of its argument.  For example, ``'%r %s' % ('abc',
+'abc')`` returns a string containing ``'abc' abc``.
+
+Previously there was no way to implement a class that overrode Python's built-in
+:keyword:`in` operator and implemented a custom version.  ``obj in seq`` returns
+true if *obj* is present in the sequence *seq*; Python computes this by simply
+trying every index of the sequence until either *obj* is found or an
+:exc:`IndexError` is encountered.  Moshe Zadka contributed a patch which adds a
+:meth:`__contains__` magic method for providing a custom implementation for
+:keyword:`in`. Additionally, new built-in objects written in C can define what
+:keyword:`in` means for them via a new slot in the sequence protocol.
+
+Earlier versions of Python used a recursive algorithm for deleting objects.
+Deeply nested data structures could cause the interpreter to fill up the C stack
+and crash; Christian Tismer rewrote the deletion logic to fix this problem.  On
+a related note, comparing recursive objects recursed infinitely and crashed;
+Jeremy Hylton rewrote the code to no longer crash, producing a useful result
+instead.  For example, after this code::
+
+   a = []
+   b = []
+   a.append(a)
+   b.append(b)
+
+The comparison ``a==b`` returns true, because the two recursive data structures
+are isomorphic. See the thread "trashcan and PR#7" in the April 2000 archives of
+the python-dev mailing list for the discussion leading up to this
+implementation, and some useful relevant links.    Note that comparisons can now
+also raise exceptions. In earlier versions of Python, a comparison operation
+such as ``cmp(a,b)`` would always produce an answer, even if a user-defined
+:meth:`__cmp__` method encountered an error, since the resulting exception would
+simply be silently swallowed.
+
+.. % Starting URL:
+.. % http://www.python.org/pipermail/python-dev/2000-April/004834.html
+
+Work has been done on porting Python to 64-bit Windows on the Itanium processor,
+mostly by Trent Mick of ActiveState.  (Confusingly, ``sys.platform`` is still
+``'win32'`` on Win64 because it seems that for ease of porting, MS Visual C++
+treats code as 32 bit on Itanium.) PythonWin also supports Windows CE; see the
+Python CE page at http://starship.python.net/crew/mhammond/ce/ for more
+information.
+
+Another new platform is Darwin/MacOS X; initial support for it is in Python 2.0.
+Dynamic loading works, if you specify "configure --with-dyld --with-suffix=.x".
+Consult the README in the Python source distribution for more instructions.
+
+An attempt has been made to alleviate one of Python's warts, the often-confusing
+:exc:`NameError` exception when code refers to a local variable before the
+variable has been assigned a value.  For example, the following code raises an
+exception on the :keyword:`print` statement in both 1.5.2 and 2.0; in 1.5.2 a
+:exc:`NameError` exception is raised, while 2.0 raises a new
+:exc:`UnboundLocalError` exception. :exc:`UnboundLocalError` is a subclass of
+:exc:`NameError`, so any existing code that expects :exc:`NameError` to be
+raised should still work. ::
+
+   def f():
+       print "i=",i
+       i = i + 1 
+   f()
+
+Two new exceptions, :exc:`TabError` and :exc:`IndentationError`, have been
+introduced.  They're both subclasses of :exc:`SyntaxError`, and are raised when
+Python code is found to be improperly indented.
+
+
+Changes to Built-in Functions
+-----------------------------
+
+A new built-in, :func:`zip(seq1, seq2, ...)`, has been added.  :func:`zip`
+returns a list of tuples where each tuple contains the i-th element from each of
+the argument sequences.  The difference between :func:`zip` and ``map(None,
+seq1, seq2)`` is that :func:`map` pads the sequences with ``None`` if the
+sequences aren't all of the same length, while :func:`zip` truncates the
+returned list to the length of the shortest argument sequence.
+
+The :func:`int` and :func:`long` functions now accept an optional "base"
+parameter when the first argument is a string. ``int('123', 10)`` returns 123,
+while ``int('123', 16)`` returns 291.  ``int(123, 16)`` raises a
+:exc:`TypeError` exception with the message "can't convert non-string with
+explicit base".
+
+A new variable holding more detailed version information has been added to the
+:mod:`sys` module.  ``sys.version_info`` is a tuple ``(major, minor, micro,
+level, serial)`` For example, in a hypothetical 2.0.1beta1, ``sys.version_info``
+would be ``(2, 0, 1, 'beta', 1)``. *level* is a string such as ``"alpha"``,
+``"beta"``, or ``"final"`` for a final release.
+
+Dictionaries have an odd new method, :meth:`setdefault(key, default)`, which
+behaves similarly to the existing :meth:`get` method.  However, if the key is
+missing, :meth:`setdefault` both returns the value of *default* as :meth:`get`
+would do, and also inserts it into the dictionary as the value for *key*.  Thus,
+the following lines of code::
+
+   if dict.has_key( key ): return dict[key]
+   else: 
+       dict[key] = []
+       return dict[key]
+
+can be reduced to a single ``return dict.setdefault(key, [])`` statement.
+
+The interpreter sets a maximum recursion depth in order to catch runaway
+recursion before filling the C stack and causing a core dump or GPF..
+Previously this limit was fixed when you compiled Python, but in 2.0 the maximum
+recursion depth can be read and modified using :func:`sys.getrecursionlimit` and
+:func:`sys.setrecursionlimit`. The default value is 1000, and a rough maximum
+value for a given platform can be found by running a new script,
+:file:`Misc/find_recursionlimit.py`.
+
+.. % ======================================================================
+
+
+Porting to 2.0
+==============
+
+New Python releases try hard to be compatible with previous releases, and the
+record has been pretty good.  However, some changes are considered useful
+enough, usually because they fix initial design decisions that turned out to be
+actively mistaken, that breaking backward compatibility can't always be avoided.
+This section lists the changes in Python 2.0 that may cause old Python code to
+break.
+
+The change which will probably break the most code is tightening up the
+arguments accepted by some methods.  Some methods would take multiple arguments
+and treat them as a tuple, particularly various list methods such as
+:meth:`.append` and :meth:`.insert`. In earlier versions of Python, if ``L`` is
+a list, ``L.append( 1,2 )`` appends the tuple ``(1,2)`` to the list.  In Python
+2.0 this causes a :exc:`TypeError` exception to be raised, with the message:
+'append requires exactly 1 argument; 2 given'.  The fix is to simply add an
+extra set of parentheses to pass both values as a tuple:  ``L.append( (1,2) )``.
+
+The earlier versions of these methods were more forgiving because they used an
+old function in Python's C interface to parse their arguments; 2.0 modernizes
+them to use :func:`PyArg_ParseTuple`, the current argument parsing function,
+which provides more helpful error messages and treats multi-argument calls as
+errors.  If you absolutely must use 2.0 but can't fix your code, you can edit
+:file:`Objects/listobject.c` and define the preprocessor symbol
+``NO_STRICT_LIST_APPEND`` to preserve the old behaviour; this isn't recommended.
+
+Some of the functions in the :mod:`socket` module are still forgiving in this
+way.  For example, :func:`socket.connect( ('hostname', 25) )` is the correct
+form, passing a tuple representing an IP address, but :func:`socket.connect(
+'hostname', 25 )` also works. :func:`socket.connect_ex` and :func:`socket.bind`
+are similarly easy-going.  2.0alpha1 tightened these functions up, but because
+the documentation actually used the erroneous multiple argument form, many
+people wrote code which would break with the stricter checking.  GvR backed out
+the changes in the face of public reaction, so for the :mod:`socket` module, the
+documentation was fixed and the multiple argument form is simply marked as
+deprecated; it *will* be tightened up again in a future Python version.
+
+The ``\x`` escape in string literals now takes exactly 2 hex digits.  Previously
+it would consume all the hex digits following the 'x' and take the lowest 8 bits
+of the result, so ``\x123456`` was equivalent to ``\x56``.
+
+The :exc:`AttributeError` and :exc:`NameError` exceptions have a more friendly
+error message, whose text will be something like ``'Spam' instance has no
+attribute 'eggs'`` or ``name 'eggs' is not defined``.  Previously the error
+message was just the missing attribute name ``eggs``, and code written to take
+advantage of this fact will break in 2.0.
+
+Some work has been done to make integers and long integers a bit more
+interchangeable.  In 1.5.2, large-file support was added for Solaris, to allow
+reading files larger than 2 GiB; this made the :meth:`tell` method of file
+objects return a long integer instead of a regular integer.  Some code would
+subtract two file offsets and attempt to use the result to multiply a sequence
+or slice a string, but this raised a :exc:`TypeError`.  In 2.0, long integers
+can be used to multiply or slice a sequence, and it'll behave as you'd
+intuitively expect it to; ``3L * 'abc'`` produces 'abcabcabc', and
+``(0,1,2,3)[2L:4L]`` produces (2,3). Long integers can also be used in various
+contexts where previously only integers were accepted, such as in the
+:meth:`seek` method of file objects, and in the formats supported by the ``%``
+operator (``%d``, ``%i``, ``%x``, etc.).  For example, ``"%d" % 2L**64`` will
+produce the string ``18446744073709551616``.
+
+The subtlest long integer change of all is that the :func:`str` of a long
+integer no longer has a trailing 'L' character, though :func:`repr` still
+includes it.  The 'L' annoyed many people who wanted to print long integers that
+looked just like regular integers, since they had to go out of their way to chop
+off the character.  This is no longer a problem in 2.0, but code which does
+``str(longval)[:-1]`` and assumes the 'L' is there, will now lose the final
+digit.
+
+Taking the :func:`repr` of a float now uses a different formatting precision
+than :func:`str`.  :func:`repr` uses ``%.17g`` format string for C's
+:func:`sprintf`, while :func:`str` uses ``%.12g`` as before.  The effect is that
+:func:`repr` may occasionally show more decimal places than  :func:`str`, for
+certain numbers.  For example, the number 8.1 can't be represented exactly in
+binary, so ``repr(8.1)`` is ``'8.0999999999999996'``, while str(8.1) is
+``'8.1'``.
+
+The ``-X`` command-line option, which turned all standard exceptions into
+strings instead of classes, has been removed; the standard exceptions will now
+always be classes.  The :mod:`exceptions` module containing the standard
+exceptions was translated from Python to a built-in C module, written by Barry
+Warsaw and Fredrik Lundh.
+
+.. % Commented out for now -- I don't think anyone will care.
+.. % The pattern and match objects provided by SRE are C types, not Python
+.. % class instances as in 1.5.  This means you can no longer inherit from
+.. % \class{RegexObject} or \class{MatchObject}, but that shouldn't be much
+.. % of a problem since no one should have been doing that in the first
+.. % place.
+.. % ======================================================================
+
+
+Extending/Embedding Changes
+===========================
+
+Some of the changes are under the covers, and will only be apparent to people
+writing C extension modules or embedding a Python interpreter in a larger
+application.  If you aren't dealing with Python's C API, you can safely skip
+this section.
+
+The version number of the Python C API was incremented, so C extensions compiled
+for 1.5.2 must be recompiled in order to work with 2.0.  On Windows, it's not
+possible for Python 2.0 to import a third party extension built for Python 1.5.x
+due to how Windows DLLs work, so Python will raise an exception and the import
+will fail.
+
+Users of Jim Fulton's ExtensionClass module will be pleased to find out that
+hooks have been added so that ExtensionClasses are now supported by
+:func:`isinstance` and :func:`issubclass`. This means you no longer have to
+remember to write code such as ``if type(obj) == myExtensionClass``, but can use
+the more natural ``if isinstance(obj, myExtensionClass)``.
+
+The :file:`Python/importdl.c` file, which was a mass of #ifdefs to support
+dynamic loading on many different platforms, was cleaned up and reorganised by
+Greg Stein.  :file:`importdl.c` is now quite small, and platform-specific code
+has been moved into a bunch of :file:`Python/dynload_\*.c` files.  Another
+cleanup: there were also a number of :file:`my\*.h` files in the Include/
+directory that held various portability hacks; they've been merged into a single
+file, :file:`Include/pyport.h`.
+
+Vladimir Marangozov's long-awaited malloc restructuring was completed, to make
+it easy to have the Python interpreter use a custom allocator instead of C's
+standard :func:`malloc`.  For documentation, read the comments in
+:file:`Include/pymem.h` and :file:`Include/objimpl.h`.  For the lengthy
+discussions during which the interface was hammered out, see the Web archives of
+the 'patches' and 'python-dev' lists at python.org.
+
+Recent versions of the GUSI development environment for MacOS support POSIX
+threads.  Therefore, Python's POSIX threading support now works on the
+Macintosh.  Threading support using the user-space GNU ``pth`` library was also
+contributed.
+
+Threading support on Windows was enhanced, too.  Windows supports thread locks
+that use kernel objects only in case of contention; in the common case when
+there's no contention, they use simpler functions which are an order of
+magnitude faster.  A threaded version of Python 1.5.2 on NT is twice as slow as
+an unthreaded version; with the 2.0 changes, the difference is only 10%.  These
+improvements were contributed by Yakov Markovitch.
+
+Python 2.0's source now uses only ANSI C prototypes, so compiling Python now
+requires an ANSI C compiler, and can no longer be done using a compiler that
+only supports K&R C.
+
+Previously the Python virtual machine used 16-bit numbers in its bytecode,
+limiting the size of source files.  In particular, this affected the maximum
+size of literal lists and dictionaries in Python source; occasionally people who
+are generating Python code would run into this limit.  A patch by Charles G.
+Waldman raises the limit from ``2^16`` to ``2^{32}``.
+
+Three new convenience functions intended for adding constants to a module's
+dictionary at module initialization time were added: :func:`PyModule_AddObject`,
+:func:`PyModule_AddIntConstant`, and :func:`PyModule_AddStringConstant`.  Each
+of these functions takes a module object, a null-terminated C string containing
+the name to be added, and a third argument for the value to be assigned to the
+name.  This third argument is, respectively, a Python object, a C long, or a C
+string.
+
+A wrapper API was added for Unix-style signal handlers. :func:`PyOS_getsig` gets
+a signal handler and :func:`PyOS_setsig` will set a new handler.
+
+.. % ======================================================================
+
+
+Distutils: Making Modules Easy to Install
+=========================================
+
+Before Python 2.0, installing modules was a tedious affair -- there was no way
+to figure out automatically where Python is installed, or what compiler options
+to use for extension modules.  Software authors had to go through an arduous
+ritual of editing Makefiles and configuration files, which only really work on
+Unix and leave Windows and MacOS unsupported.  Python users faced wildly
+differing installation instructions which varied between different extension
+packages, which made administering a Python installation something of  a chore.
+
+The SIG for distribution utilities, shepherded by Greg Ward, has created the
+Distutils, a system to make package installation much easier.  They form the
+:mod:`distutils` package, a new part of Python's standard library. In the best
+case, installing a Python module from source will require the same steps: first
+you simply mean unpack the tarball or zip archive, and the run "``python
+setup.py install``".  The platform will be automatically detected, the compiler
+will be recognized, C extension modules will be compiled, and the distribution
+installed into the proper directory.  Optional command-line arguments provide
+more control over the installation process, the distutils package offers many
+places to override defaults -- separating the build from the install, building
+or installing in non-default directories, and more.
+
+In order to use the Distutils, you need to write a :file:`setup.py` script.  For
+the simple case, when the software contains only .py files, a minimal
+:file:`setup.py` can be just a few lines long::
+
+   from distutils.core import setup
+   setup (name = "foo", version = "1.0", 
+          py_modules = ["module1", "module2"])
+
+The :file:`setup.py` file isn't much more complicated if the software consists
+of a few packages::
+
+   from distutils.core import setup
+   setup (name = "foo", version = "1.0", 
+          packages = ["package", "package.subpackage"])
+
+A C extension can be the most complicated case; here's an example taken from
+the PyXML package::
+
+   from distutils.core import setup, Extension
+
+   expat_extension = Extension('xml.parsers.pyexpat',
+   	define_macros = [('XML_NS', None)],
+   	include_dirs = [ 'extensions/expat/xmltok',
+   	                 'extensions/expat/xmlparse' ],
+   	sources = [ 'extensions/pyexpat.c',
+   	            'extensions/expat/xmltok/xmltok.c',
+    		    'extensions/expat/xmltok/xmlrole.c',
+                     ]
+          )
+   setup (name = "PyXML", version = "0.5.4", 
+          ext_modules =[ expat_extension ] )
+
+The Distutils can also take care of creating source and binary distributions.
+The "sdist" command, run by "``python setup.py sdist``', builds a source
+distribution such as :file:`foo-1.0.tar.gz`. Adding new commands isn't
+difficult, "bdist_rpm" and "bdist_wininst" commands have already been
+contributed to create an RPM distribution and a Windows installer for the
+software, respectively.  Commands to create other distribution formats such as
+Debian packages and Solaris :file:`.pkg` files are in various stages of
+development.
+
+All this is documented in a new manual, *Distributing Python Modules*, that
+joins the basic set of Python documentation.
+
+.. % ======================================================================
+
+
+XML Modules
+===========
+
+Python 1.5.2 included a simple XML parser in the form of the :mod:`xmllib`
+module, contributed by Sjoerd Mullender.  Since 1.5.2's release, two different
+interfaces for processing XML have become common: SAX2 (version 2 of the Simple
+API for XML) provides an event-driven interface with some similarities to
+:mod:`xmllib`, and the DOM (Document Object Model) provides a tree-based
+interface, transforming an XML document into a tree of nodes that can be
+traversed and modified.  Python 2.0 includes a SAX2 interface and a stripped-
+down DOM interface as part of the :mod:`xml` package. Here we will give a brief
+overview of these new interfaces; consult the Python documentation or the source
+code for complete details. The Python XML SIG is also working on improved
+documentation.
+
+
+SAX2 Support
+------------
+
+SAX defines an event-driven interface for parsing XML.  To use SAX, you must
+write a SAX handler class.  Handler classes inherit from various classes
+provided by SAX, and override various methods that will then be called by the
+XML parser.  For example, the :meth:`startElement` and :meth:`endElement`
+methods are called for every starting and end tag encountered by the parser, the
+:meth:`characters` method is called for every chunk of character data, and so
+forth.
+
+The advantage of the event-driven approach is that the whole document doesn't
+have to be resident in memory at any one time, which matters if you are
+processing really huge documents.  However, writing the SAX handler class can
+get very complicated if you're trying to modify the document structure in some
+elaborate way.
+
+For example, this little example program defines a handler that prints a message
+for every starting and ending tag, and then parses the file :file:`hamlet.xml`
+using it::
+
+   from xml import sax
+
+   class SimpleHandler(sax.ContentHandler):
+       def startElement(self, name, attrs):
+           print 'Start of element:', name, attrs.keys()
+
+       def endElement(self, name):
+           print 'End of element:', name
+
+   # Create a parser object
+   parser = sax.make_parser()
+
+   # Tell it what handler to use
+   handler = SimpleHandler()
+   parser.setContentHandler( handler )
+
+   # Parse a file!
+   parser.parse( 'hamlet.xml' )
+
+For more information, consult the Python documentation, or the XML HOWTO at
+http://pyxml.sourceforge.net/topics/howto/xml-howto.html.
+
+
+DOM Support
+-----------
+
+The Document Object Model is a tree-based representation for an XML document.  A
+top-level :class:`Document` instance is the root of the tree, and has a single
+child which is the top-level :class:`Element` instance. This :class:`Element`
+has children nodes representing character data and any sub-elements, which may
+have further children of their own, and so forth.  Using the DOM you can
+traverse the resulting tree any way you like, access element and attribute
+values, insert and delete nodes, and convert the tree back into XML.
+
+The DOM is useful for modifying XML documents, because you can create a DOM
+tree, modify it by adding new nodes or rearranging subtrees, and then produce a
+new XML document as output.  You can also construct a DOM tree manually and
+convert it to XML, which can be a more flexible way of producing XML output than
+simply writing ``<tag1>``...\ ``</tag1>`` to a file.
+
+The DOM implementation included with Python lives in the :mod:`xml.dom.minidom`
+module.  It's a lightweight implementation of the Level 1 DOM with support for
+XML namespaces.  The  :func:`parse` and :func:`parseString` convenience
+functions are provided for generating a DOM tree::
+
+   from xml.dom import minidom
+   doc = minidom.parse('hamlet.xml')
+
+``doc`` is a :class:`Document` instance.  :class:`Document`, like all the other
+DOM classes such as :class:`Element` and :class:`Text`, is a subclass of the
+:class:`Node` base class.  All the nodes in a DOM tree therefore support certain
+common methods, such as :meth:`toxml` which returns a string containing the XML
+representation of the node and its children.  Each class also has special
+methods of its own; for example, :class:`Element` and :class:`Document`
+instances have a method to find all child elements with a given tag name.
+Continuing from the previous 2-line example::
+
+   perslist = doc.getElementsByTagName( 'PERSONA' )
+   print perslist[0].toxml()
+   print perslist[1].toxml()
+
+For the *Hamlet* XML file, the above few lines output::
+
+   <PERSONA>CLAUDIUS, king of Denmark. </PERSONA>
+   <PERSONA>HAMLET, son to the late, and nephew to the present king.</PERSONA>
+
+The root element of the document is available as ``doc.documentElement``, and
+its children can be easily modified by deleting, adding, or removing nodes::
+
+   root = doc.documentElement
+
+   # Remove the first child
+   root.removeChild( root.childNodes[0] )
+
+   # Move the new first child to the end
+   root.appendChild( root.childNodes[0] )
+
+   # Insert the new first child (originally,
+   # the third child) before the 20th child.
+   root.insertBefore( root.childNodes[0], root.childNodes[20] )
+
+Again, I will refer you to the Python documentation for a complete listing of
+the different :class:`Node` classes and their various methods.
+
+
+Relationship to PyXML
+---------------------
+
+The XML Special Interest Group has been working on XML-related Python code for a
+while.  Its code distribution, called PyXML, is available from the SIG's Web
+pages at http://www.python.org/sigs/xml-sig/. The PyXML distribution also used
+the package name ``xml``.  If you've written programs that used PyXML, you're
+probably wondering about its compatibility with the 2.0 :mod:`xml` package.
+
+The answer is that Python 2.0's :mod:`xml` package isn't compatible with PyXML,
+but can be made compatible by installing a recent version PyXML.  Many
+applications can get by with the XML support that is included with Python 2.0,
+but more complicated applications will require that the full PyXML package will
+be installed.  When installed, PyXML versions 0.6.0 or greater will replace the
+:mod:`xml` package shipped with Python, and will be a strict superset of the
+standard package, adding a bunch of additional features.  Some of the additional
+features in PyXML include:
+
+* 4DOM, a full DOM implementation from FourThought, Inc.
+
+* The xmlproc validating parser, written by Lars Marius Garshol.
+
+* The :mod:`sgmlop` parser accelerator module, written by Fredrik Lundh.
+
+.. % ======================================================================
+
+
+Module changes
+==============
+
+Lots of improvements and bugfixes were made to Python's extensive standard
+library; some of the affected modules include :mod:`readline`,
+:mod:`ConfigParser`, :mod:`cgi`, :mod:`calendar`, :mod:`posix`, :mod:`readline`,
+:mod:`xmllib`, :mod:`aifc`, :mod:`chunk, wave`, :mod:`random`, :mod:`shelve`,
+and :mod:`nntplib`.  Consult the CVS logs for the exact patch-by-patch details.
+
+Brian Gallew contributed OpenSSL support for the :mod:`socket` module.  OpenSSL
+is an implementation of the Secure Socket Layer, which encrypts the data being
+sent over a socket.  When compiling Python, you can edit :file:`Modules/Setup`
+to include SSL support, which adds an additional function to the :mod:`socket`
+module: :func:`socket.ssl(socket, keyfile, certfile)`, which takes a socket
+object and returns an SSL socket.  The :mod:`httplib` and :mod:`urllib` modules
+were also changed to support "https://" URLs, though no one has implemented FTP
+or SMTP over SSL.
+
+The :mod:`httplib` module has been rewritten by Greg Stein to support HTTP/1.1.
+Backward compatibility with the 1.5 version of :mod:`httplib` is provided,
+though using HTTP/1.1 features such as pipelining will require rewriting code to
+use a different set of interfaces.
+
+The :mod:`Tkinter` module now supports Tcl/Tk version 8.1, 8.2, or 8.3, and
+support for the older 7.x versions has been dropped.  The Tkinter module now
+supports displaying Unicode strings in Tk widgets. Also, Fredrik Lundh
+contributed an optimization which makes operations like ``create_line`` and
+``create_polygon`` much faster, especially when using lots of coordinates.
+
+The :mod:`curses` module has been greatly extended, starting from Oliver
+Andrich's enhanced version, to provide many additional functions from ncurses
+and SYSV curses, such as colour, alternative character set support, pads, and
+mouse support.  This means the module is no longer compatible with operating
+systems that only have BSD curses, but there don't seem to be any currently
+maintained OSes that fall into this category.
+
+As mentioned in the earlier discussion of 2.0's Unicode support, the underlying
+implementation of the regular expressions provided by the :mod:`re` module has
+been changed.  SRE, a new regular expression engine written by Fredrik Lundh and
+partially funded by Hewlett Packard, supports matching against both 8-bit
+strings and Unicode strings.
+
+.. % ======================================================================
+
+
+New modules
+===========
+
+A number of new modules were added.  We'll simply list them with brief
+descriptions; consult the 2.0 documentation for the details of a particular
+module.
+
+* :mod:`atexit`:  For registering functions to be called before the Python
+  interpreter exits. Code that currently sets ``sys.exitfunc`` directly should be
+  changed to  use the :mod:`atexit` module instead, importing :mod:`atexit` and
+  calling :func:`atexit.register` with  the function to be called on exit.
+  (Contributed by Skip Montanaro.)
+
+* :mod:`codecs`, :mod:`encodings`, :mod:`unicodedata`:  Added as part of the new
+  Unicode support.
+
+* :mod:`filecmp`: Supersedes the old :mod:`cmp`, :mod:`cmpcache` and
+  :mod:`dircmp` modules, which have now become deprecated. (Contributed by Gordon
+  MacMillan and Moshe Zadka.)
+
+* :mod:`gettext`: This module provides internationalization (I18N) and
+  localization (L10N) support for Python programs by providing an interface to the
+  GNU gettext message catalog library. (Integrated by Barry Warsaw, from separate
+  contributions by Martin  von Löwis, Peter Funk, and James Henstridge.)
+
+* :mod:`linuxaudiodev`: Support for the :file:`/dev/audio` device on Linux, a
+  twin to the existing :mod:`sunaudiodev` module. (Contributed by Peter Bosch,
+  with fixes by Jeremy Hylton.)
+
+* :mod:`mmap`: An interface to memory-mapped files on both Windows and Unix.  A
+  file's contents can be mapped directly into memory, at which point it behaves
+  like a mutable string, so its contents can be read and modified.  They can even
+  be passed to functions that expect ordinary strings, such as the :mod:`re`
+  module. (Contributed by Sam Rushing, with some extensions by A.M. Kuchling.)
+
+* :mod:`pyexpat`: An interface to the Expat XML parser. (Contributed by Paul
+  Prescod.)
+
+* :mod:`robotparser`: Parse a :file:`robots.txt` file, which is used for writing
+  Web spiders that politely avoid certain areas of a Web site.  The parser accepts
+  the contents of a :file:`robots.txt` file, builds a set of rules from it, and
+  can then answer questions about the fetchability of a given URL.  (Contributed
+  by Skip Montanaro.)
+
+* :mod:`tabnanny`: A module/script to  check Python source code for ambiguous
+  indentation. (Contributed by Tim Peters.)
+
+* :mod:`UserString`: A base class useful for deriving objects that behave like
+  strings.
+
+* :mod:`webbrowser`: A module that provides a platform independent way to launch
+  a web browser on a specific URL. For each platform, various browsers are tried
+  in a specific order. The user can alter which browser is launched by setting the
+  *BROWSER* environment variable.  (Originally inspired by Eric S. Raymond's patch
+  to :mod:`urllib` which added similar functionality, but the final module comes
+  from code originally  implemented by Fred Drake as
+  :file:`Tools/idle/BrowserControl.py`, and adapted for the standard library by
+  Fred.)
+
+* :mod:`_winreg`: An interface to the Windows registry.  :mod:`_winreg` is an
+  adaptation of functions that have been part of PythonWin since 1995, but has now
+  been added to the core  distribution, and enhanced to support Unicode.
+  :mod:`_winreg` was written by Bill Tutt and Mark Hammond.
+
+* :mod:`zipfile`: A module for reading and writing ZIP-format archives.  These
+  are archives produced by :program:`PKZIP` on DOS/Windows or :program:`zip` on
+  Unix, not to be confused with :program:`gzip`\ -format files (which are
+  supported by the :mod:`gzip` module) (Contributed by James C. Ahlstrom.)
+
+* :mod:`imputil`: A module that provides a simpler way for writing customised
+  import hooks, in comparison to the existing :mod:`ihooks` module.  (Implemented
+  by Greg Stein, with much discussion on python-dev along the way.)
+
+.. % ======================================================================
+
+
+IDLE Improvements
+=================
+
+IDLE is the official Python cross-platform IDE, written using Tkinter. Python
+2.0 includes IDLE 0.6, which adds a number of new features and improvements.  A
+partial list:
+
+* UI improvements and optimizations, especially in the area of syntax
+  highlighting and auto-indentation.
+
+* The class browser now shows more information, such as the top level functions
+  in a module.
+
+* Tab width is now a user settable option. When opening an existing Python file,
+  IDLE automatically detects the indentation conventions, and adapts.
+
+* There is now support for calling browsers on various platforms, used to open
+  the Python documentation in a browser.
+
+* IDLE now has a command line, which is largely similar to  the vanilla Python
+  interpreter.
+
+* Call tips were added in many places.
+
+* IDLE can now be installed as a package.
+
+* In the editor window, there is now a line/column bar at the bottom.
+
+* Three new keystroke commands: Check module (Alt-F5), Import module (F5) and
+  Run script (Ctrl-F5).
+
+.. % ======================================================================
+
+
+Deleted and Deprecated Modules
+==============================
+
+A few modules have been dropped because they're obsolete, or because there are
+now better ways to do the same thing.  The :mod:`stdwin` module is gone; it was
+for a platform-independent windowing toolkit that's no longer developed.
+
+A number of modules have been moved to the :file:`lib-old` subdirectory:
+:mod:`cmp`, :mod:`cmpcache`, :mod:`dircmp`, :mod:`dump`,  :mod:`find`,
+:mod:`grep`, :mod:`packmail`,  :mod:`poly`, :mod:`util`, :mod:`whatsound`,
+:mod:`zmod`.  If you have code which relies on a module  that's been moved to
+:file:`lib-old`, you can simply add that directory to ``sys.path``   to get them
+back, but you're encouraged to update any code that uses these modules.
+
+
+Acknowledgements
+================
+
+The authors would like to thank the following people for offering suggestions on
+various drafts of this article: David Bolen, Mark Hammond, Gregg Hauser, Jeremy
+Hylton, Fredrik Lundh, Detlef Lannert, Aahz Maruch, Skip Montanaro, Vladimir
+Marangozov, Tobias Polzin, Guido van Rossum, Neil Schemenauer, and Russ Schmidt.
+
diff --git a/Doc/whatsnew/2.1.rst b/Doc/whatsnew/2.1.rst
new file mode 100644
index 0000000..2be11ba
--- /dev/null
+++ b/Doc/whatsnew/2.1.rst
@@ -0,0 +1,794 @@
+****************************
+  What's New in Python 2.1  
+****************************
+
+:Author: A.M. Kuchling
+
+.. |release| replace:: 1.01
+
+.. % $Id: whatsnew21.tex 51211 2006-08-11 14:57:12Z thomas.wouters $
+
+
+Introduction
+============
+
+This article explains the new features in Python 2.1.  While there aren't as
+many changes in 2.1 as there were in Python 2.0, there are still some pleasant
+surprises in store.  2.1 is the first release to be steered through the use of
+Python Enhancement Proposals, or PEPs, so most of the sizable changes have
+accompanying PEPs that provide more complete documentation and a design
+rationale for the change.  This article doesn't attempt to document the new
+features completely, but simply provides an overview of the new features for
+Python programmers. Refer to the Python 2.1 documentation, or to the specific
+PEP, for more details about any new feature that particularly interests you.
+
+One recent goal of the Python development team has been to accelerate the pace
+of new releases, with a new release coming every 6 to 9 months. 2.1 is the first
+release to come out at this faster pace, with the first alpha appearing in
+January, 3 months after the final version of 2.0 was released.
+
+The final release of Python 2.1 was made on April 17, 2001.
+
+.. % ======================================================================
+
+
+PEP 227: Nested Scopes
+======================
+
+The largest change in Python 2.1 is to Python's scoping rules.  In Python 2.0,
+at any given time there are at most three namespaces used to look up variable
+names: local, module-level, and the built-in namespace.  This often surprised
+people because it didn't match their intuitive expectations.  For example, a
+nested recursive function definition doesn't work::
+
+   def f():
+       ...
+       def g(value):
+           ...
+           return g(value-1) + 1
+       ...
+
+The function :func:`g` will always raise a :exc:`NameError` exception, because
+the binding of the name ``g`` isn't in either its local namespace or in the
+module-level namespace.  This isn't much of a problem in practice (how often do
+you recursively define interior functions like this?), but this also made using
+the :keyword:`lambda` statement clumsier, and this was a problem in practice.
+In code which uses :keyword:`lambda` you can often find local variables being
+copied by passing them as the default values of arguments. ::
+
+   def find(self, name):
+       "Return list of any entries equal to 'name'"
+       L = filter(lambda x, name=name: x == name,
+                  self.list_attribute)
+       return L
+
+The readability of Python code written in a strongly functional style suffers
+greatly as a result.
+
+The most significant change to Python 2.1 is that static scoping has been added
+to the language to fix this problem.  As a first effect, the ``name=name``
+default argument is now unnecessary in the above example.  Put simply, when a
+given variable name is not assigned a value within a function (by an assignment,
+or the :keyword:`def`, :keyword:`class`, or :keyword:`import` statements),
+references to the variable will be looked up in the local namespace of the
+enclosing scope.  A more detailed explanation of the rules, and a dissection of
+the implementation, can be found in the PEP.
+
+This change may cause some compatibility problems for code where the same
+variable name is used both at the module level and as a local variable within a
+function that contains further function definitions. This seems rather unlikely
+though, since such code would have been pretty confusing to read in the first
+place.
+
+One side effect of the change is that the ``from module import *`` and
+:keyword:`exec` statements have been made illegal inside a function scope under
+certain conditions.  The Python reference manual has said all along that ``from
+module import *`` is only legal at the top level of a module, but the CPython
+interpreter has never enforced this before.  As part of the implementation of
+nested scopes, the compiler which turns Python source into bytecodes has to
+generate different code to access variables in a containing scope.  ``from
+module import *`` and :keyword:`exec` make it impossible for the compiler to
+figure this out, because they add names to the local namespace that are
+unknowable at compile time. Therefore, if a function contains function
+definitions or :keyword:`lambda` expressions with free variables, the compiler
+will flag this by raising a :exc:`SyntaxError` exception.
+
+To make the preceding explanation a bit clearer, here's an example::
+
+   x = 1
+   def f():
+       # The next line is a syntax error
+       exec 'x=2'  
+       def g():
+           return x
+
+Line 4 containing the :keyword:`exec` statement is a syntax error, since
+:keyword:`exec` would define a new local variable named ``x`` whose value should
+be accessed by :func:`g`.
+
+This shouldn't be much of a limitation, since :keyword:`exec` is rarely used in
+most Python code (and when it is used, it's often a sign of a poor design
+anyway).
+
+Compatibility concerns have led to nested scopes being introduced gradually; in
+Python 2.1, they aren't enabled by default, but can be turned on within a module
+by using a future statement as described in PEP 236.  (See the following section
+for further discussion of PEP 236.)  In Python 2.2, nested scopes will become
+the default and there will be no way to turn them off, but users will have had
+all of 2.1's lifetime to fix any breakage resulting from their introduction.
+
+
+.. seealso::
+
+   :pep:`227` - Statically Nested Scopes
+      Written and implemented by Jeremy Hylton.
+
+.. % ======================================================================
+
+
+PEP 236: __future__ Directives
+==============================
+
+The reaction to nested scopes was widespread concern about the dangers of
+breaking code with the 2.1 release, and it was strong enough to make the
+Pythoneers take a more conservative approach.  This approach consists of
+introducing a convention for enabling optional functionality in release N that
+will become compulsory in release N+1.
+
+The syntax uses a ``from...import`` statement using the reserved module name
+:mod:`__future__`.  Nested scopes can be enabled by the following statement::
+
+   from __future__ import nested_scopes
+
+While it looks like a normal :keyword:`import` statement, it's not; there are
+strict rules on where such a future statement can be put. They can only be at
+the top of a module, and must precede any Python code or regular
+:keyword:`import` statements.  This is because such statements can affect how
+the Python bytecode compiler parses code and generates bytecode, so they must
+precede any statement that will result in bytecodes being produced.
+
+
+.. seealso::
+
+   :pep:`236` - Back to the :mod:`__future__`
+      Written by Tim Peters, and primarily implemented by Jeremy Hylton.
+
+.. % ======================================================================
+
+
+PEP 207: Rich Comparisons
+=========================
+
+In earlier versions, Python's support for implementing comparisons on user-
+defined classes and extension types was quite simple. Classes could implement a
+:meth:`__cmp__` method that was given two instances of a class, and could only
+return 0 if they were equal or +1 or -1 if they weren't; the method couldn't
+raise an exception or return anything other than a Boolean value.  Users of
+Numeric Python often found this model too weak and restrictive, because in the
+number-crunching programs that numeric Python is used for, it would be more
+useful to be able to perform elementwise comparisons of two matrices, returning
+a matrix containing the results of a given comparison for each element.  If the
+two matrices are of different sizes, then the compare has to be able to raise an
+exception to signal the error.
+
+In Python 2.1, rich comparisons were added in order to support this need.
+Python classes can now individually overload each of the ``<``, ``<=``, ``>``,
+``>=``, ``==``, and ``!=`` operations.  The new magic method names are:
+
++-----------+----------------+
+| Operation | Method name    |
++===========+================+
+| ``<``     | :meth:`__lt__` |
++-----------+----------------+
+| ``<=``    | :meth:`__le__` |
++-----------+----------------+
+| ``>``     | :meth:`__gt__` |
++-----------+----------------+
+| ``>=``    | :meth:`__ge__` |
++-----------+----------------+
+| ``==``    | :meth:`__eq__` |
++-----------+----------------+
+| ``!=``    | :meth:`__ne__` |
++-----------+----------------+
+
+(The magic methods are named after the corresponding Fortran operators ``.LT.``.
+``.LE.``, &c.  Numeric programmers are almost certainly quite familiar with
+these names and will find them easy to remember.)
+
+Each of these magic methods is of the form ``method(self, other)``, where
+``self`` will be the object on the left-hand side of the operator, while
+``other`` will be the object on the right-hand side.  For example, the
+expression ``A < B`` will cause ``A.__lt__(B)`` to be called.
+
+Each of these magic methods can return anything at all: a Boolean, a matrix, a
+list, or any other Python object.  Alternatively they can raise an exception if
+the comparison is impossible, inconsistent, or otherwise meaningless.
+
+The built-in :func:`cmp(A,B)` function can use the rich comparison machinery,
+and now accepts an optional argument specifying which comparison operation to
+use; this is given as one of the strings ``"<"``, ``"<="``, ``">"``, ``">="``,
+``"=="``, or ``"!="``.  If called without the optional third argument,
+:func:`cmp` will only return -1, 0, or +1 as in previous versions of Python;
+otherwise it will call the appropriate method and can return any Python object.
+
+There are also corresponding changes of interest to C programmers; there's a new
+slot ``tp_richcmp`` in type objects and an API for performing a given rich
+comparison.  I won't cover the C API here, but will refer you to PEP 207, or to
+2.1's C API documentation, for the full list of related functions.
+
+
+.. seealso::
+
+   :pep:`207` - Rich Comparisions
+      Written by Guido van Rossum, heavily based on earlier work by David Ascher, and
+      implemented by Guido van Rossum.
+
+.. % ======================================================================
+
+
+PEP 230: Warning Framework
+==========================
+
+Over its 10 years of existence, Python has accumulated a certain number of
+obsolete modules and features along the way.  It's difficult to know when a
+feature is safe to remove, since there's no way of knowing how much code uses it
+--- perhaps no programs depend on the feature, or perhaps many do.  To enable
+removing old features in a more structured way, a warning framework was added.
+When the Python developers want to get rid of a feature, it will first trigger a
+warning in the next version of Python.  The following Python version can then
+drop the feature, and users will have had a full release cycle to remove uses of
+the old feature.
+
+Python 2.1 adds the warning framework to be used in this scheme.  It adds a
+:mod:`warnings` module that provide functions to issue warnings, and to filter
+out warnings that you don't want to be displayed. Third-party modules can also
+use this framework to deprecate old features that they no longer wish to
+support.
+
+For example, in Python 2.1 the :mod:`regex` module is deprecated, so importing
+it causes a warning to be printed::
+
+   >>> import regex
+   __main__:1: DeprecationWarning: the regex module
+            is deprecated; please use the re module
+   >>>
+
+Warnings can be issued by calling the :func:`warnings.warn` function::
+
+   warnings.warn("feature X no longer supported")
+
+The first parameter is the warning message; an additional optional parameters
+can be used to specify a particular warning category.
+
+Filters can be added to disable certain warnings; a regular expression pattern
+can be applied to the message or to the module name in order to suppress a
+warning.  For example, you may have a program that uses the :mod:`regex` module
+and not want to spare the time to convert it to use the :mod:`re` module right
+now.  The warning can be suppressed by calling ::
+
+   import warnings
+   warnings.filterwarnings(action = 'ignore',
+                           message='.*regex module is deprecated',
+                           category=DeprecationWarning,
+                           module = '__main__')
+
+This adds a filter that will apply only to warnings of the class
+:class:`DeprecationWarning` triggered in the :mod:`__main__` module, and applies
+a regular expression to only match the message about the :mod:`regex` module
+being deprecated, and will cause such warnings to be ignored.  Warnings can also
+be printed only once, printed every time the offending code is executed, or
+turned into exceptions that will cause the program to stop (unless the
+exceptions are caught in the usual way, of course).
+
+Functions were also added to Python's C API for issuing warnings; refer to PEP
+230 or to Python's API documentation for the details.
+
+
+.. seealso::
+
+   :pep:`5` - Guidelines for Language Evolution
+      Written by Paul Prescod, to specify procedures to be followed when removing old
+      features from Python.  The policy described in this PEP hasn't been officially
+      adopted, but the eventual policy probably won't be too different from Prescod's
+      proposal.
+
+   :pep:`230` - Warning Framework
+      Written and implemented by Guido van Rossum.
+
+.. % ======================================================================
+
+
+PEP 229: New Build System
+=========================
+
+When compiling Python, the user had to go in and edit the :file:`Modules/Setup`
+file in order to enable various additional modules; the default set is
+relatively small and limited to modules that compile on most Unix platforms.
+This means that on Unix platforms with many more features, most notably Linux,
+Python installations often don't contain all useful modules they could.
+
+Python 2.0 added the Distutils, a set of modules for distributing and installing
+extensions.  In Python 2.1, the Distutils are used to compile much of the
+standard library of extension modules, autodetecting which ones are supported on
+the current machine.  It's hoped that this will make Python installations easier
+and more featureful.
+
+Instead of having to edit the :file:`Modules/Setup` file in order to enable
+modules, a :file:`setup.py` script in the top directory of the Python source
+distribution is run at build time, and attempts to discover which modules can be
+enabled by examining the modules and header files on the system.  If a module is
+configured in :file:`Modules/Setup`, the :file:`setup.py` script won't attempt
+to compile that module and will defer to the :file:`Modules/Setup` file's
+contents.  This provides a way to specific any strange command-line flags or
+libraries that are required for a specific platform.
+
+In another far-reaching change to the build mechanism, Neil Schemenauer
+restructured things so Python now uses a single makefile that isn't recursive,
+instead of makefiles in the top directory and in each of the :file:`Python/`,
+:file:`Parser/`, :file:`Objects/`, and :file:`Modules/` subdirectories.  This
+makes building Python faster and also makes hacking the Makefiles clearer and
+simpler.
+
+
+.. seealso::
+
+   :pep:`229` - Using Distutils to Build Python
+      Written and implemented by A.M. Kuchling.
+
+.. % ======================================================================
+
+
+PEP 205: Weak References
+========================
+
+Weak references, available through the :mod:`weakref` module, are a minor but
+useful new data type in the Python programmer's toolbox.
+
+Storing a reference to an object (say, in a dictionary or a list) has the side
+effect of keeping that object alive forever.  There are a few specific cases
+where this behaviour is undesirable, object caches being the most common one,
+and another being circular references in data structures such as trees.
+
+For example, consider a memoizing function that caches the results of another
+function :func:`f(x)` by storing the function's argument and its result in a
+dictionary::
+
+   _cache = {}
+   def memoize(x):
+       if _cache.has_key(x):
+           return _cache[x]
+
+       retval = f(x)
+
+       # Cache the returned object
+       _cache[x] = retval
+
+       return retval
+
+This version works for simple things such as integers, but it has a side effect;
+the ``_cache`` dictionary holds a reference to the return values, so they'll
+never be deallocated until the Python process exits and cleans up This isn't
+very noticeable for integers, but if :func:`f` returns an object, or a data
+structure that takes up a lot of memory, this can be a problem.
+
+Weak references provide a way to implement a cache that won't keep objects alive
+beyond their time.  If an object is only accessible through weak references, the
+object will be deallocated and the weak references will now indicate that the
+object it referred to no longer exists.  A weak reference to an object *obj* is
+created by calling ``wr = weakref.ref(obj)``.  The object being referred to is
+returned by calling the weak reference as if it were a function: ``wr()``.  It
+will return the referenced object, or ``None`` if the object no longer exists.
+
+This makes it possible to write a :func:`memoize` function whose cache doesn't
+keep objects alive, by storing weak references in the cache. ::
+
+   _cache = {}
+   def memoize(x):
+       if _cache.has_key(x):
+           obj = _cache[x]()
+           # If weak reference object still exists,
+           # return it
+           if obj is not None: return obj
+
+       retval = f(x)
+
+       # Cache a weak reference
+       _cache[x] = weakref.ref(retval)
+
+       return retval
+
+The :mod:`weakref` module also allows creating proxy objects which behave like
+weak references --- an object referenced only by proxy objects is deallocated --
+but instead of requiring an explicit call to retrieve the object, the proxy
+transparently forwards all operations to the object as long as the object still
+exists.  If the object is deallocated, attempting to use a proxy will cause a
+:exc:`weakref.ReferenceError` exception to be raised. ::
+
+   proxy = weakref.proxy(obj)
+   proxy.attr   # Equivalent to obj.attr
+   proxy.meth() # Equivalent to obj.meth()
+   del obj
+   proxy.attr   # raises weakref.ReferenceError
+
+
+.. seealso::
+
+   :pep:`205` - Weak References
+      Written and implemented by Fred L. Drake, Jr.
+
+.. % ======================================================================
+
+
+PEP 232: Function Attributes
+============================
+
+In Python 2.1, functions can now have arbitrary information attached to them.
+People were often using docstrings to hold information about functions and
+methods, because the ``__doc__`` attribute was the only way of attaching any
+information to a function.  For example, in the Zope Web application server,
+functions are marked as safe for public access by having a docstring, and in
+John Aycock's SPARK parsing framework, docstrings hold parts of the BNF grammar
+to be parsed.  This overloading is unfortunate, since docstrings are really
+intended to hold a function's documentation; for example, it means you can't
+properly document functions intended for private use in Zope.
+
+Arbitrary attributes can now be set and retrieved on functions using the regular
+Python syntax::
+
+   def f(): pass
+
+   f.publish = 1
+   f.secure = 1
+   f.grammar = "A ::= B (C D)*"
+
+The dictionary containing attributes can be accessed as the function's
+:attr:`__dict__`. Unlike the :attr:`__dict__` attribute of class instances, in
+functions you can actually assign a new dictionary to :attr:`__dict__`, though
+the new value is restricted to a regular Python dictionary; you *can't* be
+tricky and set it to a :class:`UserDict` instance, or any other random object
+that behaves like a mapping.
+
+
+.. seealso::
+
+   :pep:`232` - Function Attributes
+      Written and implemented by Barry Warsaw.
+
+.. % ======================================================================
+
+
+PEP 235: Importing Modules on Case-Insensitive Platforms
+========================================================
+
+Some operating systems have filesystems that are case-insensitive, MacOS and
+Windows being the primary examples; on these systems, it's impossible to
+distinguish the filenames ``FILE.PY`` and ``file.py``, even though they do store
+the file's name  in its original case (they're case-preserving, too).
+
+In Python 2.1, the :keyword:`import` statement will work to simulate case-
+sensitivity on case-insensitive platforms.  Python will now search for the first
+case-sensitive match by default, raising an :exc:`ImportError` if no such file
+is found, so ``import file`` will not import a module named ``FILE.PY``.  Case-
+insensitive matching can be requested by setting the :envvar:`PYTHONCASEOK`
+environment variable before starting the Python interpreter.
+
+.. % ======================================================================
+
+
+PEP 217: Interactive Display Hook
+=================================
+
+When using the Python interpreter interactively, the output of commands is
+displayed using the built-in :func:`repr` function. In Python 2.1, the variable
+:func:`sys.displayhook` can be set to a callable object which will be called
+instead of :func:`repr`. For example, you can set it to a special pretty-
+printing function::
+
+   >>> # Create a recursive data structure
+   ... L = [1,2,3]
+   >>> L.append(L)
+   >>> L # Show Python's default output
+   [1, 2, 3, [...]]
+   >>> # Use pprint.pprint() as the display function
+   ... import sys, pprint
+   >>> sys.displayhook = pprint.pprint
+   >>> L
+   [1, 2, 3,  <Recursion on list with id=135143996>]
+   >>>
+
+
+.. seealso::
+
+   :pep:`217` - Display Hook for Interactive Use
+      Written and implemented by Moshe Zadka.
+
+.. % ======================================================================
+
+
+PEP 208: New Coercion Model
+===========================
+
+How numeric coercion is done at the C level was significantly modified.  This
+will only affect the authors of C extensions to Python, allowing them more
+flexibility in writing extension types that support numeric operations.
+
+Extension types can now set the type flag ``Py_TPFLAGS_CHECKTYPES`` in their
+``PyTypeObject`` structure to indicate that they support the new coercion model.
+In such extension types, the numeric slot functions can no longer assume that
+they'll be passed two arguments of the same type; instead they may be passed two
+arguments of differing types, and can then perform their own internal coercion.
+If the slot function is passed a type it can't handle, it can indicate the
+failure by returning a reference to the ``Py_NotImplemented`` singleton value.
+The numeric functions of the other type will then be tried, and perhaps they can
+handle the operation; if the other type also returns ``Py_NotImplemented``, then
+a :exc:`TypeError` will be raised.  Numeric methods written in Python can also
+return ``Py_NotImplemented``, causing the interpreter to act as if the method
+did not exist (perhaps raising a :exc:`TypeError`, perhaps trying another
+object's numeric methods).
+
+
+.. seealso::
+
+   :pep:`208` - Reworking the Coercion Model
+      Written and implemented by Neil Schemenauer, heavily based upon earlier work by
+      Marc-André Lemburg.  Read this to understand the fine points of how numeric
+      operations will now be processed at the C level.
+
+.. % ======================================================================
+
+
+PEP 241: Metadata in Python Packages
+====================================
+
+A common complaint from Python users is that there's no single catalog of all
+the Python modules in existence.  T. Middleton's Vaults of Parnassus at
+http://www.vex.net/parnassus/ are the largest catalog of Python modules, but
+registering software at the Vaults is optional, and many people don't bother.
+
+As a first small step toward fixing the problem, Python software packaged using
+the Distutils :command:`sdist` command will include a file named
+:file:`PKG-INFO` containing information about the package such as its name,
+version, and author (metadata, in cataloguing terminology).  PEP 241 contains
+the full list of fields that can be present in the :file:`PKG-INFO` file.  As
+people began to package their software using Python 2.1, more and more packages
+will include metadata, making it possible to build automated cataloguing systems
+and experiment with them.  With the result experience, perhaps it'll be possible
+to design a really good catalog and then build support for it into Python 2.2.
+For example, the Distutils :command:`sdist` and :command:`bdist_\*` commands
+could support a :option:`upload` option that would automatically upload your
+package to a catalog server.
+
+You can start creating packages containing :file:`PKG-INFO` even if you're not
+using Python 2.1, since a new release of the Distutils will be made for users of
+earlier Python versions.  Version 1.0.2 of the Distutils includes the changes
+described in PEP 241, as well as various bugfixes and enhancements.  It will be
+available from  the Distutils SIG at http://www.python.org/sigs/distutils-sig/.
+
+
+.. seealso::
+
+   :pep:`241` - Metadata for Python Software Packages
+      Written and implemented by A.M. Kuchling.
+
+   :pep:`243` - Module Repository Upload Mechanism
+      Written by Sean Reifschneider, this draft PEP describes a proposed mechanism for
+      uploading  Python packages to a central server.
+
+.. % ======================================================================
+
+
+New and Improved Modules
+========================
+
+* Ka-Ping Yee contributed two new modules: :mod:`inspect.py`, a module for
+  getting information about live Python code, and :mod:`pydoc.py`, a module for
+  interactively converting docstrings to HTML or text.  As a bonus,
+  :file:`Tools/scripts/pydoc`, which is now automatically installed, uses
+  :mod:`pydoc.py` to display documentation given a Python module, package, or
+  class name.  For example, ``pydoc xml.dom`` displays the following::
+
+     Python Library Documentation: package xml.dom in xml
+
+     NAME
+         xml.dom - W3C Document Object Model implementation for Python.
+
+     FILE
+         /usr/local/lib/python2.1/xml/dom/__init__.pyc
+
+     DESCRIPTION
+         The Python mapping of the Document Object Model is documented in the
+         Python Library Reference in the section on the xml.dom package.
+
+         This package contains the following modules:
+           ...
+
+  :file:`pydoc` also includes a Tk-based interactive help browser.   :file:`pydoc`
+  quickly becomes addictive; try it out!
+
+* Two different modules for unit testing were added to the standard library.
+  The :mod:`doctest` module, contributed by Tim Peters, provides a testing
+  framework based on running embedded examples in docstrings and comparing the
+  results against the expected output.  PyUnit, contributed by Steve Purcell, is a
+  unit testing framework inspired by JUnit, which was in turn an adaptation of
+  Kent Beck's Smalltalk testing framework.  See http://pyunit.sourceforge.net/ for
+  more information about PyUnit.
+
+* The :mod:`difflib` module contains a class, :class:`SequenceMatcher`, which
+  compares two sequences and computes the changes required to transform one
+  sequence into the other.  For example, this module can be used to write a tool
+  similar to the Unix :program:`diff` program, and in fact the sample program
+  :file:`Tools/scripts/ndiff.py` demonstrates how to write such a script.
+
+* :mod:`curses.panel`, a wrapper for the panel library, part of ncurses and of
+  SYSV curses, was contributed by Thomas Gellekum.  The panel library provides
+  windows with the additional feature of depth. Windows can be moved higher or
+  lower in the depth ordering, and the panel library figures out where panels
+  overlap and which sections are visible.
+
+* The PyXML package has gone through a few releases since Python 2.0, and Python
+  2.1 includes an updated version of the :mod:`xml` package.  Some of the
+  noteworthy changes include support for Expat 1.2 and later versions, the ability
+  for Expat parsers to handle files in any encoding supported by Python, and
+  various bugfixes for SAX, DOM, and the :mod:`minidom` module.
+
+* Ping also contributed another hook for handling uncaught exceptions.
+  :func:`sys.excepthook` can be set to a callable object.  When an exception isn't
+  caught by any :keyword:`try`...\ :keyword:`except` blocks, the exception will be
+  passed to :func:`sys.excepthook`, which can then do whatever it likes.  At the
+  Ninth Python Conference, Ping demonstrated an application for this hook:
+  printing an extended traceback that not only lists the stack frames, but also
+  lists the function arguments and the local variables for each frame.
+
+* Various functions in the :mod:`time` module, such as :func:`asctime` and
+  :func:`localtime`, require a floating point argument containing the time in
+  seconds since the epoch.  The most common use of these functions is to work with
+  the current time, so the floating point argument has been made optional; when a
+  value isn't provided, the current time will be used.  For example, log file
+  entries usually need a string containing the current time; in Python 2.1,
+  ``time.asctime()`` can be used, instead of the lengthier
+  ``time.asctime(time.localtime(time.time()))`` that was previously required.
+
+  This change was proposed and implemented by Thomas Wouters.
+
+* The :mod:`ftplib` module now defaults to retrieving files in passive mode,
+  because passive mode is more likely to work from behind a firewall.  This
+  request came from the Debian bug tracking system, since other Debian packages
+  use :mod:`ftplib` to retrieve files and then don't work from behind a firewall.
+  It's deemed unlikely that this will cause problems for anyone, because Netscape
+  defaults to passive mode and few people complain, but if passive mode is
+  unsuitable for your application or network setup, call :meth:`set_pasv(0)` on
+  FTP objects to disable passive mode.
+
+* Support for raw socket access has been added to the :mod:`socket` module,
+  contributed by Grant Edwards.
+
+* The :mod:`pstats` module now contains a simple interactive statistics browser
+  for displaying timing profiles for Python programs, invoked when the module is
+  run as a script.  Contributed by  Eric S. Raymond.
+
+* A new implementation-dependent function, :func:`sys._getframe([depth])`, has
+  been added to return a given frame object from the current call stack.
+  :func:`sys._getframe` returns the frame at the top of the call stack;  if the
+  optional integer argument *depth* is supplied, the function returns the frame
+  that is *depth* calls below the top of the stack.  For example,
+  ``sys._getframe(1)`` returns the caller's frame object.
+
+  This function is only present in CPython, not in Jython or the .NET
+  implementation.  Use it for debugging, and resist the temptation to put it into
+  production code.
+
+.. % ======================================================================
+
+
+Other Changes and Fixes
+=======================
+
+There were relatively few smaller changes made in Python 2.1 due to the shorter
+release cycle.  A search through the CVS change logs turns up 117 patches
+applied, and 136 bugs fixed; both figures are likely to be underestimates.  Some
+of the more notable changes are:
+
+* A specialized object allocator is now optionally available, that should be
+  faster than the system :func:`malloc` and have less memory overhead.  The
+  allocator uses C's :func:`malloc` function to get large pools of memory, and
+  then fulfills smaller memory requests from these pools.  It can be enabled by
+  providing the :option:`--with-pymalloc` option to the :program:`configure`
+  script; see :file:`Objects/obmalloc.c` for the implementation details.
+
+  Authors of C extension modules should test their code with the object allocator
+  enabled, because some incorrect code may break, causing core dumps at runtime.
+  There are a bunch of memory allocation functions in Python's C API that have
+  previously been just aliases for the C library's :func:`malloc` and
+  :func:`free`, meaning that if you accidentally called mismatched functions, the
+  error wouldn't be noticeable.  When the object allocator is enabled, these
+  functions aren't aliases of :func:`malloc` and :func:`free` any more, and
+  calling the wrong function to free memory will get you a core dump.  For
+  example, if memory was allocated using :func:`PyMem_New`, it has to be freed
+  using :func:`PyMem_Del`, not :func:`free`.  A few modules included with Python
+  fell afoul of this and had to be fixed; doubtless there are more third-party
+  modules that will have the same problem.
+
+  The object allocator was contributed by Vladimir Marangozov.
+
+* The speed of line-oriented file I/O has been improved because people often
+  complain about its lack of speed, and because it's often been used as a naïve
+  benchmark.  The :meth:`readline` method of file objects has therefore been
+  rewritten to be much faster.  The exact amount of the speedup will vary from
+  platform to platform depending on how slow the C library's :func:`getc` was, but
+  is around 66%, and potentially much faster on some particular operating systems.
+  Tim Peters did much of the benchmarking and coding for this change, motivated by
+  a discussion in comp.lang.python.
+
+  A new module and method for file objects was also added, contributed by Jeff
+  Epler. The new method, :meth:`xreadlines`, is similar to the existing
+  :func:`xrange` built-in.  :func:`xreadlines` returns an opaque sequence object
+  that only supports being iterated over, reading a line on every iteration but
+  not reading the entire file into memory as the existing :meth:`readlines` method
+  does. You'd use it like this::
+
+     for line in sys.stdin.xreadlines():
+         # ... do something for each line ...
+         ...
+
+  For a fuller discussion of the line I/O changes, see the python-dev summary for
+  January 1-15, 2001 at http://www.python.org/dev/summary/2001-01-1.html.
+
+* A new method, :meth:`popitem`, was added to dictionaries to enable
+  destructively iterating through the contents of a dictionary; this can be faster
+  for large dictionaries because there's no need to construct a list containing
+  all the keys or values. ``D.popitem()`` removes a random ``(key, value)`` pair
+  from the dictionary ``D`` and returns it as a 2-tuple.  This was implemented
+  mostly by Tim Peters and Guido van Rossum, after a suggestion and preliminary
+  patch by Moshe Zadka.
+
+* Modules can now control which names are imported when ``from module import *``
+  is used, by defining an ``__all__`` attribute containing a list of names that
+  will be imported.  One common complaint is that if the module imports other
+  modules such as :mod:`sys` or :mod:`string`, ``from module import *`` will add
+  them to the importing module's namespace.  To fix this, simply list the public
+  names in ``__all__``::
+
+     # List public names
+     __all__ = ['Database', 'open']
+
+  A stricter version of this patch was first suggested and implemented by Ben
+  Wolfson, but after some python-dev discussion, a weaker final version was
+  checked in.
+
+* Applying :func:`repr` to strings previously used octal escapes for
+  non-printable characters; for example, a newline was ``'\012'``.  This was a
+  vestigial trace of Python's C ancestry, but today octal is of very little
+  practical use.  Ka-Ping Yee suggested using hex escapes instead of octal ones,
+  and using the ``\n``, ``\t``, ``\r`` escapes for the appropriate characters,
+  and implemented this new formatting.
+
+* Syntax errors detected at compile-time can now raise exceptions containing the
+  filename and line number of the error, a pleasant side effect of the compiler
+  reorganization done by Jeremy Hylton.
+
+* C extensions which import other modules have been changed to use
+  :func:`PyImport_ImportModule`, which means that they will use any import hooks
+  that have been installed.  This is also encouraged for third-party extensions
+  that need to import some other module from C code.
+
+* The size of the Unicode character database was shrunk by another 340K thanks
+  to Fredrik Lundh.
+
+* Some new ports were contributed: MacOS X (by Steven Majewski), Cygwin (by
+  Jason Tishler); RISCOS (by Dietmar Schwertberger); Unixware 7  (by Billy G.
+  Allie).
+
+And there's the usual list of minor bugfixes, minor memory leaks, docstring
+edits, and other tweaks, too lengthy to be worth itemizing; see the CVS logs for
+the full details if you want them.
+
+.. % ======================================================================
+
+
+Acknowledgements
+================
+
+The author would like to thank the following people for offering suggestions on
+various drafts of this article: Graeme Cross, David Goodger, Jay Graves, Michael
+Hudson, Marc-André Lemburg, Fredrik Lundh, Neil Schemenauer, Thomas Wouters.
+
diff --git a/Doc/whatsnew/2.2.rst b/Doc/whatsnew/2.2.rst
new file mode 100644
index 0000000..6a7e0e8
--- /dev/null
+++ b/Doc/whatsnew/2.2.rst
@@ -0,0 +1,1269 @@
+****************************
+  What's New in Python 2.2  
+****************************
+
+:Author: A.M. Kuchling
+
+.. |release| replace:: 1.02
+
+.. % $Id: whatsnew22.tex 37315 2004-09-10 19:33:00Z akuchling $
+
+
+Introduction
+============
+
+This article explains the new features in Python 2.2.2, released on October 14,
+2002.  Python 2.2.2 is a bugfix release of Python 2.2, originally released on
+December 21, 2001.
+
+Python 2.2 can be thought of as the "cleanup release".  There are some features
+such as generators and iterators that are completely new, but most of the
+changes, significant and far-reaching though they may be, are aimed at cleaning
+up irregularities and dark corners of the language design.
+
+This article doesn't attempt to provide a complete specification of the new
+features, but instead provides a convenient overview.  For full details, you
+should refer to the documentation for Python 2.2, such as the `Python Library
+Reference <http://www.python.org/doc/2.2/lib/lib.html>`_ and the `Python
+Reference Manual <http://www.python.org/doc/2.2/ref/ref.html>`_.  If you want to
+understand the complete implementation and design rationale for a change, refer
+to the PEP for a particular new feature.
+
+
+.. seealso::
+
+   http://www.unixreview.com/documents/s=1356/urm0109h/0109h.htm
+      "What's So Special About Python 2.2?" is also about the new 2.2 features, and
+      was written by Cameron Laird and Kathryn Soraiz.
+
+.. % ======================================================================
+
+
+PEPs 252 and 253: Type and Class Changes
+========================================
+
+The largest and most far-reaching changes in Python 2.2 are to Python's model of
+objects and classes.  The changes should be backward compatible, so it's likely
+that your code will continue to run unchanged, but the changes provide some
+amazing new capabilities. Before beginning this, the longest and most
+complicated section of this article, I'll provide an overview of the changes and
+offer some comments.
+
+A long time ago I wrote a Web page (http://www.amk.ca/python/writing/warts.html)
+listing flaws in Python's design.  One of the most significant flaws was that
+it's impossible to subclass Python types implemented in C.  In particular, it's
+not possible to subclass built-in types, so you can't just subclass, say, lists
+in order to add a single useful method to them. The :mod:`UserList` module
+provides a class that supports all of the methods of lists and that can be
+subclassed further, but there's lots of C code that expects a regular Python
+list and won't accept a :class:`UserList` instance.
+
+Python 2.2 fixes this, and in the process adds some exciting new capabilities.
+A brief summary:
+
+* You can subclass built-in types such as lists and even integers, and your
+  subclasses should work in every place that requires the original type.
+
+* It's now possible to define static and class methods, in addition to the
+  instance methods available in previous versions of Python.
+
+* It's also possible to automatically call methods on accessing or setting an
+  instance attribute by using a new mechanism called :dfn:`properties`.  Many uses
+  of :meth:`__getattr__` can be rewritten to use properties instead, making the
+  resulting code simpler and faster.  As a small side benefit, attributes can now
+  have docstrings, too.
+
+* The list of legal attributes for an instance can be limited to a particular
+  set using :dfn:`slots`, making it possible to safeguard against typos and
+  perhaps make more optimizations possible in future versions of Python.
+
+Some users have voiced concern about all these changes.  Sure, they say, the new
+features are neat and lend themselves to all sorts of tricks that weren't
+possible in previous versions of Python, but they also make the language more
+complicated.  Some people have said that they've always recommended Python for
+its simplicity, and feel that its simplicity is being lost.
+
+Personally, I think there's no need to worry.  Many of the new features are
+quite esoteric, and you can write a lot of Python code without ever needed to be
+aware of them.  Writing a simple class is no more difficult than it ever was, so
+you don't need to bother learning or teaching them unless they're actually
+needed.  Some very complicated tasks that were previously only possible from C
+will now be possible in pure Python, and to my mind that's all for the better.
+
+I'm not going to attempt to cover every single corner case and small change that
+were required to make the new features work.  Instead this section will paint
+only the broad strokes.  See section :ref:`sect-rellinks`, "Related Links", for
+further sources of information about Python 2.2's new object model.
+
+
+Old and New Classes
+-------------------
+
+First, you should know that Python 2.2 really has two kinds of classes: classic
+or old-style classes, and new-style classes.  The old-style class model is
+exactly the same as the class model in earlier versions of Python.  All the new
+features described in this section apply only to new-style classes. This
+divergence isn't intended to last forever; eventually old-style classes will be
+dropped, possibly in Python 3.0.
+
+So how do you define a new-style class?  You do it by subclassing an existing
+new-style class.  Most of Python's built-in types, such as integers, lists,
+dictionaries, and even files, are new-style classes now.  A new-style class
+named :class:`object`, the base class for all built-in types, has also been
+added so if no built-in type is suitable, you can just subclass
+:class:`object`::
+
+   class C(object):
+       def __init__ (self):
+           ...
+       ...
+
+This means that :keyword:`class` statements that don't have any base classes are
+always classic classes in Python 2.2.  (Actually you can also change this by
+setting a module-level variable named :attr:`__metaclass__` --- see :pep:`253`
+for the details --- but it's easier to just subclass :keyword:`object`.)
+
+The type objects for the built-in types are available as built-ins, named using
+a clever trick.  Python has always had built-in functions named :func:`int`,
+:func:`float`, and :func:`str`.  In 2.2, they aren't functions any more, but
+type objects that behave as factories when called. ::
+
+   >>> int
+   <type 'int'>
+   >>> int('123')
+   123
+
+To make the set of types complete, new type objects such as :func:`dict` and
+:func:`file` have been added.  Here's a more interesting example, adding a
+:meth:`lock` method to file objects::
+
+   class LockableFile(file):
+       def lock (self, operation, length=0, start=0, whence=0):
+           import fcntl
+           return fcntl.lockf(self.fileno(), operation,
+                              length, start, whence)
+
+The now-obsolete :mod:`posixfile` module contained a class that emulated all of
+a file object's methods and also added a :meth:`lock` method, but this class
+couldn't be passed to internal functions that expected a built-in file,
+something which is possible with our new :class:`LockableFile`.
+
+
+Descriptors
+-----------
+
+In previous versions of Python, there was no consistent way to discover what
+attributes and methods were supported by an object. There were some informal
+conventions, such as defining :attr:`__members__` and :attr:`__methods__`
+attributes that were lists of names, but often the author of an extension type
+or a class wouldn't bother to define them.  You could fall back on inspecting
+the :attr:`__dict__` of an object, but when class inheritance or an arbitrary
+:meth:`__getattr__` hook were in use this could still be inaccurate.
+
+The one big idea underlying the new class model is that an API for describing
+the attributes of an object using :dfn:`descriptors` has been formalized.
+Descriptors specify the value of an attribute, stating whether it's a method or
+a field.  With the descriptor API, static methods and class methods become
+possible, as well as more exotic constructs.
+
+Attribute descriptors are objects that live inside class objects, and have a few
+attributes of their own:
+
+* :attr:`__name__` is the attribute's name.
+
+* :attr:`__doc__` is the attribute's docstring.
+
+* :meth:`__get__(object)` is a method that retrieves the attribute value from
+  *object*.
+
+* :meth:`__set__(object, value)` sets the attribute on *object* to *value*.
+
+* :meth:`__delete__(object, value)` deletes the *value*  attribute of *object*.
+
+For example, when you write ``obj.x``, the steps that Python actually performs
+are::
+
+   descriptor = obj.__class__.x
+   descriptor.__get__(obj)
+
+For methods, :meth:`descriptor.__get__` returns a temporary object that's
+callable, and wraps up the instance and the method to be called on it. This is
+also why static methods and class methods are now possible; they have
+descriptors that wrap up just the method, or the method and the class.  As a
+brief explanation of these new kinds of methods, static methods aren't passed
+the instance, and therefore resemble regular functions.  Class methods are
+passed the class of the object, but not the object itself.  Static and class
+methods are defined like this::
+
+   class C(object):
+       def f(arg1, arg2):
+           ...
+       f = staticmethod(f)
+
+       def g(cls, arg1, arg2):
+           ...
+       g = classmethod(g)
+
+The :func:`staticmethod` function takes the function :func:`f`, and returns it
+wrapped up in a descriptor so it can be stored in the class object.  You might
+expect there to be special syntax for creating such methods (``def static f``,
+``defstatic f()``, or something like that) but no such syntax has been defined
+yet; that's been left for future versions of Python.
+
+More new features, such as slots and properties, are also implemented as new
+kinds of descriptors, and it's not difficult to write a descriptor class that
+does something novel.  For example, it would be possible to write a descriptor
+class that made it possible to write Eiffel-style preconditions and
+postconditions for a method.  A class that used this feature might be defined
+like this::
+
+   from eiffel import eiffelmethod
+
+   class C(object):
+       def f(self, arg1, arg2):
+           # The actual function
+           ...
+       def pre_f(self):
+           # Check preconditions
+           ...
+       def post_f(self):
+           # Check postconditions
+           ...
+
+       f = eiffelmethod(f, pre_f, post_f)
+
+Note that a person using the new :func:`eiffelmethod` doesn't have to understand
+anything about descriptors.  This is why I think the new features don't increase
+the basic complexity of the language. There will be a few wizards who need to
+know about it in order to write :func:`eiffelmethod` or the ZODB or whatever,
+but most users will just write code on top of the resulting libraries and ignore
+the implementation details.
+
+
+Multiple Inheritance: The Diamond Rule
+--------------------------------------
+
+Multiple inheritance has also been made more useful through changing the rules
+under which names are resolved.  Consider this set of classes (diagram taken
+from :pep:`253` by Guido van Rossum)::
+
+         class A:
+           ^ ^  def save(self): ...
+          /   \
+         /     \
+        /       \
+       /         \
+   class B     class C:
+       ^         ^  def save(self): ...
+        \       /
+         \     /
+          \   /
+           \ /
+         class D
+
+The lookup rule for classic classes is simple but not very smart; the base
+classes are searched depth-first, going from left to right.  A reference to
+:meth:`D.save` will search the classes :class:`D`, :class:`B`, and then
+:class:`A`, where :meth:`save` would be found and returned.  :meth:`C.save`
+would never be found at all.  This is bad, because if :class:`C`'s :meth:`save`
+method is saving some internal state specific to :class:`C`, not calling it will
+result in that state never getting saved.
+
+New-style classes follow a different algorithm that's a bit more complicated to
+explain, but does the right thing in this situation. (Note that Python 2.3
+changes this algorithm to one that produces the same results in most cases, but
+produces more useful results for really complicated inheritance graphs.)
+
+#. List all the base classes, following the classic lookup rule and include a
+   class multiple times if it's visited repeatedly.  In the above example, the list
+   of visited classes is [:class:`D`, :class:`B`, :class:`A`, :class:`C`,
+   :class:`A`].
+
+#. Scan the list for duplicated classes.  If any are found, remove all but one
+   occurrence, leaving the *last* one in the list.  In the above example, the list
+   becomes [:class:`D`, :class:`B`, :class:`C`, :class:`A`] after dropping
+   duplicates.
+
+Following this rule, referring to :meth:`D.save` will return :meth:`C.save`,
+which is the behaviour we're after.  This lookup rule is the same as the one
+followed by Common Lisp.  A new built-in function, :func:`super`, provides a way
+to get at a class's superclasses without having to reimplement Python's
+algorithm. The most commonly used form will be  :func:`super(class, obj)`, which
+returns  a bound superclass object (not the actual class object).  This form
+will be used in methods to call a method in the superclass; for example,
+:class:`D`'s :meth:`save` method would look like this::
+
+   class D (B,C):
+       def save (self):
+   	# Call superclass .save()
+           super(D, self).save()
+           # Save D's private information here
+           ...
+
+:func:`super` can also return unbound superclass objects when called as
+:func:`super(class)` or :func:`super(class1, class2)`, but this probably won't
+often be useful.
+
+
+Attribute Access
+----------------
+
+A fair number of sophisticated Python classes define hooks for attribute access
+using :meth:`__getattr__`; most commonly this is done for convenience, to make
+code more readable by automatically mapping an attribute access such as
+``obj.parent`` into a method call such as ``obj.get_parent``.  Python 2.2 adds
+some new ways of controlling attribute access.
+
+First, :meth:`__getattr__(attr_name)` is still supported by new-style classes,
+and nothing about it has changed.  As before, it will be called when an attempt
+is made to access ``obj.foo`` and no attribute named ``foo`` is found in the
+instance's dictionary.
+
+New-style classes also support a new method,
+:meth:`__getattribute__(attr_name)`.  The difference between the two methods is
+that :meth:`__getattribute__` is *always* called whenever any attribute is
+accessed, while the old :meth:`__getattr__` is only called if ``foo`` isn't
+found in the instance's dictionary.
+
+However, Python 2.2's support for :dfn:`properties` will often be a simpler way
+to trap attribute references.  Writing a :meth:`__getattr__` method is
+complicated because to avoid recursion you can't use regular attribute accesses
+inside them, and instead have to mess around with the contents of
+:attr:`__dict__`. :meth:`__getattr__` methods also end up being called by Python
+when it checks for other methods such as :meth:`__repr__` or :meth:`__coerce__`,
+and so have to be written with this in mind. Finally, calling a function on
+every attribute access results in a sizable performance loss.
+
+:class:`property` is a new built-in type that packages up three functions that
+get, set, or delete an attribute, and a docstring.  For example, if you want to
+define a :attr:`size` attribute that's computed, but also settable, you could
+write::
+
+   class C(object):
+       def get_size (self):
+           result = ... computation ...
+           return result
+       def set_size (self, size):
+           ... compute something based on the size
+           and set internal state appropriately ...
+
+       # Define a property.  The 'delete this attribute'
+       # method is defined as None, so the attribute
+       # can't be deleted.
+       size = property(get_size, set_size,
+                       None,
+                       "Storage size of this instance")
+
+That is certainly clearer and easier to write than a pair of
+:meth:`__getattr__`/:meth:`__setattr__` methods that check for the :attr:`size`
+attribute and handle it specially while retrieving all other attributes from the
+instance's :attr:`__dict__`.  Accesses to :attr:`size` are also the only ones
+which have to perform the work of calling a function, so references to other
+attributes run at their usual speed.
+
+Finally, it's possible to constrain the list of attributes that can be
+referenced on an object using the new :attr:`__slots__` class attribute. Python
+objects are usually very dynamic; at any time it's possible to define a new
+attribute on an instance by just doing ``obj.new_attr=1``.   A new-style class
+can define a class attribute named :attr:`__slots__` to limit the legal
+attributes  to a particular set of names.  An example will make this clear::
+
+   >>> class C(object):
+   ...     __slots__ = ('template', 'name')
+   ...
+   >>> obj = C()
+   >>> print obj.template
+   None
+   >>> obj.template = 'Test'
+   >>> print obj.template
+   Test
+   >>> obj.newattr = None
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   AttributeError: 'C' object has no attribute 'newattr'
+
+Note how you get an :exc:`AttributeError` on the attempt to assign to an
+attribute not listed in :attr:`__slots__`.
+
+
+.. _sect-rellinks:
+
+Related Links
+-------------
+
+This section has just been a quick overview of the new features, giving enough
+of an explanation to start you programming, but many details have been
+simplified or ignored.  Where should you go to get a more complete picture?
+
+http://www.python.org/2.2/descrintro.html is a lengthy tutorial introduction to
+the descriptor features, written by Guido van Rossum. If my description has
+whetted your appetite, go read this tutorial next, because it goes into much
+more detail about the new features while still remaining quite easy to read.
+
+Next, there are two relevant PEPs, :pep:`252` and :pep:`253`.  :pep:`252` is
+titled "Making Types Look More Like Classes", and covers the descriptor API.
+:pep:`253` is titled "Subtyping Built-in Types", and describes the changes to
+type objects that make it possible to subtype built-in objects.  :pep:`253` is
+the more complicated PEP of the two, and at a few points the necessary
+explanations of types and meta-types may cause your head to explode.  Both PEPs
+were written and implemented by Guido van Rossum, with substantial assistance
+from the rest of the Zope Corp. team.
+
+Finally, there's the ultimate authority: the source code.  Most of the machinery
+for the type handling is in :file:`Objects/typeobject.c`, but you should only
+resort to it after all other avenues have been exhausted, including posting a
+question to python-list or python-dev.
+
+.. % ======================================================================
+
+
+PEP 234: Iterators
+==================
+
+Another significant addition to 2.2 is an iteration interface at both the C and
+Python levels.  Objects can define how they can be looped over by callers.
+
+In Python versions up to 2.1, the usual way to make ``for item in obj`` work is
+to define a :meth:`__getitem__` method that looks something like this::
+
+   def __getitem__(self, index):
+       return <next item>
+
+:meth:`__getitem__` is more properly used to define an indexing operation on an
+object so that you can write ``obj[5]`` to retrieve the sixth element.  It's a
+bit misleading when you're using this only to support :keyword:`for` loops.
+Consider some file-like object that wants to be looped over; the *index*
+parameter is essentially meaningless, as the class probably assumes that a
+series of :meth:`__getitem__` calls will be made with *index* incrementing by
+one each time.  In other words, the presence of the :meth:`__getitem__` method
+doesn't mean that using ``file[5]``  to randomly access the sixth element will
+work, though it really should.
+
+In Python 2.2, iteration can be implemented separately, and :meth:`__getitem__`
+methods can be limited to classes that really do support random access.  The
+basic idea of iterators is  simple.  A new built-in function, :func:`iter(obj)`
+or ``iter(C, sentinel)``, is used to get an iterator. :func:`iter(obj)` returns
+an iterator for the object *obj*, while ``iter(C, sentinel)`` returns an
+iterator that will invoke the callable object *C* until it returns *sentinel* to
+signal that the iterator is done.
+
+Python classes can define an :meth:`__iter__` method, which should create and
+return a new iterator for the object; if the object is its own iterator, this
+method can just return ``self``.  In particular, iterators will usually be their
+own iterators.  Extension types implemented in C can implement a :attr:`tp_iter`
+function in order to return an iterator, and extension types that want to behave
+as iterators can define a :attr:`tp_iternext` function.
+
+So, after all this, what do iterators actually do?  They have one required
+method, :meth:`next`, which takes no arguments and returns the next value.  When
+there are no more values to be returned, calling :meth:`next` should raise the
+:exc:`StopIteration` exception. ::
+
+   >>> L = [1,2,3]
+   >>> i = iter(L)
+   >>> print i
+   <iterator object at 0x8116870>
+   >>> i.next()
+   1
+   >>> i.next()
+   2
+   >>> i.next()
+   3
+   >>> i.next()
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   StopIteration
+   >>>      
+
+In 2.2, Python's :keyword:`for` statement no longer expects a sequence; it
+expects something for which :func:`iter` will return an iterator. For backward
+compatibility and convenience, an iterator is automatically constructed for
+sequences that don't implement :meth:`__iter__` or a :attr:`tp_iter` slot, so
+``for i in [1,2,3]`` will still work.  Wherever the Python interpreter loops
+over a sequence, it's been changed to use the iterator protocol.  This means you
+can do things like this::
+
+   >>> L = [1,2,3]
+   >>> i = iter(L)
+   >>> a,b,c = i
+   >>> a,b,c
+   (1, 2, 3)
+
+Iterator support has been added to some of Python's basic types.   Calling
+:func:`iter` on a dictionary will return an iterator which loops over its keys::
+
+   >>> m = {'Jan': 1, 'Feb': 2, 'Mar': 3, 'Apr': 4, 'May': 5, 'Jun': 6,
+   ...      'Jul': 7, 'Aug': 8, 'Sep': 9, 'Oct': 10, 'Nov': 11, 'Dec': 12}
+   >>> for key in m: print key, m[key]
+   ...
+   Mar 3
+   Feb 2
+   Aug 8
+   Sep 9
+   May 5
+   Jun 6
+   Jul 7
+   Jan 1
+   Apr 4
+   Nov 11
+   Dec 12
+   Oct 10
+
+That's just the default behaviour.  If you want to iterate over keys, values, or
+key/value pairs, you can explicitly call the :meth:`iterkeys`,
+:meth:`itervalues`, or :meth:`iteritems` methods to get an appropriate iterator.
+In a minor related change, the :keyword:`in` operator now works on dictionaries,
+so ``key in dict`` is now equivalent to ``dict.has_key(key)``.
+
+Files also provide an iterator, which calls the :meth:`readline` method until
+there are no more lines in the file.  This means you can now read each line of a
+file using code like this::
+
+   for line in file:
+       # do something for each line
+       ...
+
+Note that you can only go forward in an iterator; there's no way to get the
+previous element, reset the iterator, or make a copy of it. An iterator object
+could provide such additional capabilities, but the iterator protocol only
+requires a :meth:`next` method.
+
+
+.. seealso::
+
+   :pep:`234` - Iterators
+      Written by Ka-Ping Yee and GvR; implemented  by the Python Labs crew, mostly by
+      GvR and Tim Peters.
+
+.. % ======================================================================
+
+
+PEP 255: Simple Generators
+==========================
+
+Generators are another new feature, one that interacts with the introduction of
+iterators.
+
+You're doubtless familiar with how function calls work in Python or C.  When you
+call a function, it gets a private namespace where its local variables are
+created.  When the function reaches a :keyword:`return` statement, the local
+variables are destroyed and the resulting value is returned to the caller.  A
+later call to the same function will get a fresh new set of local variables.
+But, what if the local variables weren't thrown away on exiting a function?
+What if you could later resume the function where it left off?  This is what
+generators provide; they can be thought of as resumable functions.
+
+Here's the simplest example of a generator function::
+
+   def generate_ints(N):
+       for i in range(N):
+           yield i
+
+A new keyword, :keyword:`yield`, was introduced for generators.  Any function
+containing a :keyword:`yield` statement is a generator function; this is
+detected by Python's bytecode compiler which compiles the function specially as
+a result.  Because a new keyword was introduced, generators must be explicitly
+enabled in a module by including a ``from __future__ import generators``
+statement near the top of the module's source code.  In Python 2.3 this
+statement will become unnecessary.
+
+When you call a generator function, it doesn't return a single value; instead it
+returns a generator object that supports the iterator protocol.  On executing
+the :keyword:`yield` statement, the generator outputs the value of ``i``,
+similar to a :keyword:`return` statement.  The big difference between
+:keyword:`yield` and a :keyword:`return` statement is that on reaching a
+:keyword:`yield` the generator's state of execution is suspended and local
+variables are preserved.  On the next call to the generator's ``next()`` method,
+the function will resume executing immediately after the :keyword:`yield`
+statement.  (For complicated reasons, the :keyword:`yield` statement isn't
+allowed inside the :keyword:`try` block of a :keyword:`try`...\
+:keyword:`finally` statement; read :pep:`255` for a full explanation of the
+interaction between :keyword:`yield` and exceptions.)
+
+Here's a sample usage of the :func:`generate_ints` generator::
+
+   >>> gen = generate_ints(3)
+   >>> gen
+   <generator object at 0x8117f90>
+   >>> gen.next()
+   0
+   >>> gen.next()
+   1
+   >>> gen.next()
+   2
+   >>> gen.next()
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+     File "<stdin>", line 2, in generate_ints
+   StopIteration
+
+You could equally write ``for i in generate_ints(5)``, or ``a,b,c =
+generate_ints(3)``.
+
+Inside a generator function, the :keyword:`return` statement can only be used
+without a value, and signals the end of the procession of values; afterwards the
+generator cannot return any further values. :keyword:`return` with a value, such
+as ``return 5``, is a syntax error inside a generator function.  The end of the
+generator's results can also be indicated by raising :exc:`StopIteration`
+manually, or by just letting the flow of execution fall off the bottom of the
+function.
+
+You could achieve the effect of generators manually by writing your own class
+and storing all the local variables of the generator as instance variables.  For
+example, returning a list of integers could be done by setting ``self.count`` to
+0, and having the :meth:`next` method increment ``self.count`` and return it.
+However, for a moderately complicated generator, writing a corresponding class
+would be much messier. :file:`Lib/test/test_generators.py` contains a number of
+more interesting examples.  The simplest one implements an in-order traversal of
+a tree using generators recursively. ::
+
+   # A recursive generator that generates Tree leaves in in-order.
+   def inorder(t):
+       if t:
+           for x in inorder(t.left):
+               yield x
+           yield t.label
+           for x in inorder(t.right):
+               yield x
+
+Two other examples in :file:`Lib/test/test_generators.py` produce solutions for
+the N-Queens problem (placing $N$ queens on an $NxN$ chess board so that no
+queen threatens another) and the Knight's Tour (a route that takes a knight to
+every square of an $NxN$ chessboard without visiting any square twice).
+
+The idea of generators comes from other programming languages, especially Icon
+(http://www.cs.arizona.edu/icon/), where the idea of generators is central.  In
+Icon, every expression and function call behaves like a generator.  One example
+from "An Overview of the Icon Programming Language" at
+http://www.cs.arizona.edu/icon/docs/ipd266.htm gives an idea of what this looks
+like::
+
+   sentence := "Store it in the neighboring harbor"
+   if (i := find("or", sentence)) > 5 then write(i)
+
+In Icon the :func:`find` function returns the indexes at which the substring
+"or" is found: 3, 23, 33.  In the :keyword:`if` statement, ``i`` is first
+assigned a value of 3, but 3 is less than 5, so the comparison fails, and Icon
+retries it with the second value of 23.  23 is greater than 5, so the comparison
+now succeeds, and the code prints the value 23 to the screen.
+
+Python doesn't go nearly as far as Icon in adopting generators as a central
+concept.  Generators are considered a new part of the core Python language, but
+learning or using them isn't compulsory; if they don't solve any problems that
+you have, feel free to ignore them. One novel feature of Python's interface as
+compared to Icon's is that a generator's state is represented as a concrete
+object (the iterator) that can be passed around to other functions or stored in
+a data structure.
+
+
+.. seealso::
+
+   :pep:`255` - Simple Generators
+      Written by Neil Schemenauer, Tim Peters, Magnus Lie Hetland.  Implemented mostly
+      by Neil Schemenauer and Tim Peters, with other fixes from the Python Labs crew.
+
+.. % ======================================================================
+
+
+PEP 237: Unifying Long Integers and Integers
+============================================
+
+In recent versions, the distinction between regular integers, which are 32-bit
+values on most machines, and long integers, which can be of arbitrary size, was
+becoming an annoyance.  For example, on platforms that support files larger than
+``2**32`` bytes, the :meth:`tell` method of file objects has to return a long
+integer. However, there were various bits of Python that expected plain integers
+and would raise an error if a long integer was provided instead.  For example,
+in Python 1.5, only regular integers could be used as a slice index, and
+``'abc'[1L:]`` would raise a :exc:`TypeError` exception with the message 'slice
+index must be int'.
+
+Python 2.2 will shift values from short to long integers as required. The 'L'
+suffix is no longer needed to indicate a long integer literal, as now the
+compiler will choose the appropriate type.  (Using the 'L' suffix will be
+discouraged in future 2.x versions of Python, triggering a warning in Python
+2.4, and probably dropped in Python 3.0.)  Many operations that used to raise an
+:exc:`OverflowError` will now return a long integer as their result.  For
+example::
+
+   >>> 1234567890123
+   1234567890123L
+   >>> 2 ** 64
+   18446744073709551616L
+
+In most cases, integers and long integers will now be treated identically.  You
+can still distinguish them with the :func:`type` built-in function, but that's
+rarely needed.
+
+
+.. seealso::
+
+   :pep:`237` - Unifying Long Integers and Integers
+      Written by Moshe Zadka and Guido van Rossum.  Implemented mostly by Guido van
+      Rossum.
+
+.. % ======================================================================
+
+
+PEP 238: Changing the Division Operator
+=======================================
+
+The most controversial change in Python 2.2 heralds the start of an effort to
+fix an old design flaw that's been in Python from the beginning. Currently
+Python's division operator, ``/``, behaves like C's division operator when
+presented with two integer arguments: it returns an integer result that's
+truncated down when there would be a fractional part.  For example, ``3/2`` is
+1, not 1.5, and ``(-1)/2`` is -1, not -0.5.  This means that the results of
+divison can vary unexpectedly depending on the type of the two operands and
+because Python is dynamically typed, it can be difficult to determine the
+possible types of the operands.
+
+(The controversy is over whether this is *really* a design flaw, and whether
+it's worth breaking existing code to fix this.  It's caused endless discussions
+on python-dev, and in July 2001 erupted into an storm of acidly sarcastic
+postings on :newsgroup:`comp.lang.python`. I won't argue for either side here
+and will stick to describing what's  implemented in 2.2.  Read :pep:`238` for a
+summary of arguments and counter-arguments.)
+
+Because this change might break code, it's being introduced very gradually.
+Python 2.2 begins the transition, but the switch won't be complete until Python
+3.0.
+
+First, I'll borrow some terminology from :pep:`238`.  "True division" is the
+division that most non-programmers are familiar with: 3/2 is 1.5, 1/4 is 0.25,
+and so forth.  "Floor division" is what Python's ``/`` operator currently does
+when given integer operands; the result is the floor of the value returned by
+true division.  "Classic division" is the current mixed behaviour of ``/``; it
+returns the result of floor division when the operands are integers, and returns
+the result of true division when one of the operands is a floating-point number.
+
+Here are the changes 2.2 introduces:
+
+* A new operator, ``//``, is the floor division operator. (Yes, we know it looks
+  like C++'s comment symbol.)  ``//`` *always* performs floor division no matter
+  what the types of its operands are, so ``1 // 2`` is 0 and ``1.0 // 2.0`` is
+  also 0.0.
+
+  ``//`` is always available in Python 2.2; you don't need to enable it using a
+  ``__future__`` statement.
+
+* By including a ``from __future__ import division`` in a module, the ``/``
+  operator will be changed to return the result of true division, so ``1/2`` is
+  0.5.  Without the ``__future__`` statement, ``/`` still means classic division.
+  The default meaning of ``/`` will not change until Python 3.0.
+
+* Classes can define methods called :meth:`__truediv__` and :meth:`__floordiv__`
+  to overload the two division operators.  At the C level, there are also slots in
+  the :ctype:`PyNumberMethods` structure so extension types can define the two
+  operators.
+
+* Python 2.2 supports some command-line arguments for testing whether code will
+  works with the changed division semantics.  Running python with :option:`-Q
+  warn` will cause a warning to be issued whenever division is applied to two
+  integers.  You can use this to find code that's affected by the change and fix
+  it.  By default, Python 2.2 will simply perform classic division without a
+  warning; the warning will be turned on by default in Python 2.3.
+
+
+.. seealso::
+
+   :pep:`238` - Changing the Division Operator
+      Written by Moshe Zadka and  Guido van Rossum.  Implemented by Guido van Rossum..
+
+.. % ======================================================================
+
+
+Unicode Changes
+===============
+
+Python's Unicode support has been enhanced a bit in 2.2.  Unicode strings are
+usually stored as UCS-2, as 16-bit unsigned integers. Python 2.2 can also be
+compiled to use UCS-4, 32-bit unsigned integers, as its internal encoding by
+supplying :option:`--enable-unicode=ucs4` to the configure script.   (It's also
+possible to specify :option:`--disable-unicode` to completely disable Unicode
+support.)
+
+When built to use UCS-4 (a "wide Python"), the interpreter can natively handle
+Unicode characters from U+000000 to U+110000, so the range of legal values for
+the :func:`unichr` function is expanded accordingly.  Using an interpreter
+compiled to use UCS-2 (a "narrow Python"), values greater than 65535 will still
+cause :func:`unichr` to raise a :exc:`ValueError` exception. This is all
+described in :pep:`261`, "Support for 'wide' Unicode characters"; consult it for
+further details.
+
+Another change is simpler to explain. Since their introduction, Unicode strings
+have supported an :meth:`encode` method to convert the string to a selected
+encoding such as UTF-8 or Latin-1.  A symmetric :meth:`decode([*encoding*])`
+method has been added to 8-bit strings (though not to Unicode strings) in 2.2.
+:meth:`decode` assumes that the string is in the specified encoding and decodes
+it, returning whatever is returned by the codec.
+
+Using this new feature, codecs have been added for tasks not directly related to
+Unicode.  For example, codecs have been added for uu-encoding, MIME's base64
+encoding, and compression with the :mod:`zlib` module::
+
+   >>> s = """Here is a lengthy piece of redundant, overly verbose,
+   ... and repetitive text.
+   ... """
+   >>> data = s.encode('zlib')
+   >>> data
+   'x\x9c\r\xc9\xc1\r\x80 \x10\x04\xc0?Ul...'
+   >>> data.decode('zlib')
+   'Here is a lengthy piece of redundant, overly verbose,\nand repetitive text.\n'
+   >>> print s.encode('uu')
+   begin 666 <data>
+   M2&5R92!I<R!A(&QE;F=T:'D@<&EE8V4@;V8@<F5D=6YD86YT+"!O=F5R;'D@
+   >=F5R8F]S92P*86YD(')E<&5T:71I=F4@=&5X="X*
+
+   end
+   >>> "sheesh".encode('rot-13')
+   'furrfu'
+
+To convert a class instance to Unicode, a :meth:`__unicode__` method can be
+defined by a class, analogous to :meth:`__str__`.
+
+:meth:`encode`, :meth:`decode`, and :meth:`__unicode__` were implemented by
+Marc-André Lemburg.  The changes to support using UCS-4 internally were
+implemented by Fredrik Lundh and Martin von Löwis.
+
+
+.. seealso::
+
+   :pep:`261` - Support for 'wide' Unicode characters
+      Written by Paul Prescod.
+
+.. % ======================================================================
+
+
+PEP 227: Nested Scopes
+======================
+
+In Python 2.1, statically nested scopes were added as an optional feature, to be
+enabled by a ``from __future__ import nested_scopes`` directive.  In 2.2 nested
+scopes no longer need to be specially enabled, and are now always present.  The
+rest of this section is a copy of the description of nested scopes from my
+"What's New in Python 2.1" document; if you read it when 2.1 came out, you can
+skip the rest of this section.
+
+The largest change introduced in Python 2.1, and made complete in 2.2, is to
+Python's scoping rules.  In Python 2.0, at any given time there are at most
+three namespaces used to look up variable names: local, module-level, and the
+built-in namespace.  This often surprised people because it didn't match their
+intuitive expectations.  For example, a nested recursive function definition
+doesn't work::
+
+   def f():
+       ...
+       def g(value):
+           ...
+           return g(value-1) + 1
+       ...
+
+The function :func:`g` will always raise a :exc:`NameError` exception, because
+the binding of the name ``g`` isn't in either its local namespace or in the
+module-level namespace.  This isn't much of a problem in practice (how often do
+you recursively define interior functions like this?), but this also made using
+the :keyword:`lambda` statement clumsier, and this was a problem in practice.
+In code which uses :keyword:`lambda` you can often find local variables being
+copied by passing them as the default values of arguments. ::
+
+   def find(self, name):
+       "Return list of any entries equal to 'name'"
+       L = filter(lambda x, name=name: x == name,
+                  self.list_attribute)
+       return L
+
+The readability of Python code written in a strongly functional style suffers
+greatly as a result.
+
+The most significant change to Python 2.2 is that static scoping has been added
+to the language to fix this problem.  As a first effect, the ``name=name``
+default argument is now unnecessary in the above example.  Put simply, when a
+given variable name is not assigned a value within a function (by an assignment,
+or the :keyword:`def`, :keyword:`class`, or :keyword:`import` statements),
+references to the variable will be looked up in the local namespace of the
+enclosing scope.  A more detailed explanation of the rules, and a dissection of
+the implementation, can be found in the PEP.
+
+This change may cause some compatibility problems for code where the same
+variable name is used both at the module level and as a local variable within a
+function that contains further function definitions. This seems rather unlikely
+though, since such code would have been pretty confusing to read in the first
+place.
+
+One side effect of the change is that the ``from module import *`` and
+:keyword:`exec` statements have been made illegal inside a function scope under
+certain conditions.  The Python reference manual has said all along that ``from
+module import *`` is only legal at the top level of a module, but the CPython
+interpreter has never enforced this before.  As part of the implementation of
+nested scopes, the compiler which turns Python source into bytecodes has to
+generate different code to access variables in a containing scope.  ``from
+module import *`` and :keyword:`exec` make it impossible for the compiler to
+figure this out, because they add names to the local namespace that are
+unknowable at compile time. Therefore, if a function contains function
+definitions or :keyword:`lambda` expressions with free variables, the compiler
+will flag this by raising a :exc:`SyntaxError` exception.
+
+To make the preceding explanation a bit clearer, here's an example::
+
+   x = 1
+   def f():
+       # The next line is a syntax error
+       exec 'x=2'  
+       def g():
+           return x
+
+Line 4 containing the :keyword:`exec` statement is a syntax error, since
+:keyword:`exec` would define a new local variable named ``x`` whose value should
+be accessed by :func:`g`.
+
+This shouldn't be much of a limitation, since :keyword:`exec` is rarely used in
+most Python code (and when it is used, it's often a sign of a poor design
+anyway).
+
+
+.. seealso::
+
+   :pep:`227` - Statically Nested Scopes
+      Written and implemented by Jeremy Hylton.
+
+.. % ======================================================================
+
+
+New and Improved Modules
+========================
+
+* The :mod:`xmlrpclib` module was contributed to the standard library by Fredrik
+  Lundh, providing support for writing XML-RPC clients.  XML-RPC is a simple
+  remote procedure call protocol built on top of HTTP and XML. For example, the
+  following snippet retrieves a list of RSS channels from the O'Reilly Network,
+  and then  lists the recent headlines for one channel::
+
+     import xmlrpclib
+     s = xmlrpclib.Server(
+           'http://www.oreillynet.com/meerkat/xml-rpc/server.php')
+     channels = s.meerkat.getChannels()
+     # channels is a list of dictionaries, like this:
+     # [{'id': 4, 'title': 'Freshmeat Daily News'}
+     #  {'id': 190, 'title': '32Bits Online'},
+     #  {'id': 4549, 'title': '3DGamers'}, ... ]
+
+     # Get the items for one channel
+     items = s.meerkat.getItems( {'channel': 4} )
+
+     # 'items' is another list of dictionaries, like this:
+     # [{'link': 'http://freshmeat.net/releases/52719/', 
+     #   'description': 'A utility which converts HTML to XSL FO.', 
+     #   'title': 'html2fo 0.3 (Default)'}, ... ]
+
+  The :mod:`SimpleXMLRPCServer` module makes it easy to create straightforward
+  XML-RPC servers.  See http://www.xmlrpc.com/ for more information about XML-RPC.
+
+* The new :mod:`hmac` module implements the HMAC algorithm described by
+  :rfc:`2104`. (Contributed by Gerhard Häring.)
+
+* Several functions that originally returned lengthy tuples now return pseudo-
+  sequences that still behave like tuples but also have mnemonic attributes such
+  as memberst_mtime or :attr:`tm_year`. The enhanced functions include
+  :func:`stat`, :func:`fstat`, :func:`statvfs`, and :func:`fstatvfs` in the
+  :mod:`os` module, and :func:`localtime`, :func:`gmtime`, and :func:`strptime` in
+  the :mod:`time` module.
+
+  For example, to obtain a file's size using the old tuples, you'd end up writing
+  something like ``file_size = os.stat(filename)[stat.ST_SIZE]``, but now this can
+  be written more clearly as ``file_size = os.stat(filename).st_size``.
+
+  The original patch for this feature was contributed by Nick Mathewson.
+
+* The Python profiler has been extensively reworked and various errors in its
+  output have been corrected.  (Contributed by Fred L. Drake, Jr. and Tim Peters.)
+
+* The :mod:`socket` module can be compiled to support IPv6; specify the
+  :option:`--enable-ipv6` option to Python's configure script.  (Contributed by
+  Jun-ichiro "itojun" Hagino.)
+
+* Two new format characters were added to the :mod:`struct` module for 64-bit
+  integers on platforms that support the C :ctype:`long long` type.  ``q`` is for
+  a signed 64-bit integer, and ``Q`` is for an unsigned one.  The value is
+  returned in Python's long integer type.  (Contributed by Tim Peters.)
+
+* In the interpreter's interactive mode, there's a new built-in function
+  :func:`help` that uses the :mod:`pydoc` module introduced in Python 2.1 to
+  provide interactive help. ``help(object)`` displays any available help text
+  about *object*.  :func:`help` with no argument puts you in an online help
+  utility, where you can enter the names of functions, classes, or modules to read
+  their help text. (Contributed by Guido van Rossum, using Ka-Ping Yee's
+  :mod:`pydoc` module.)
+
+* Various bugfixes and performance improvements have been made to the SRE engine
+  underlying the :mod:`re` module.  For example, the :func:`re.sub` and
+  :func:`re.split` functions have been rewritten in C.  Another contributed patch
+  speeds up certain Unicode character ranges by a factor of two, and a new
+  :meth:`finditer`  method that returns an iterator over all the non-overlapping
+  matches in  a given string.  (SRE is maintained by Fredrik Lundh.  The
+  BIGCHARSET patch was contributed by Martin von Löwis.)
+
+* The :mod:`smtplib` module now supports :rfc:`2487`, "Secure SMTP over TLS", so
+  it's now possible to encrypt the SMTP traffic between a Python program and the
+  mail transport agent being handed a message.  :mod:`smtplib` also supports SMTP
+  authentication.  (Contributed by Gerhard Häring.)
+
+* The :mod:`imaplib` module, maintained by Piers Lauder, has support for several
+  new extensions: the NAMESPACE extension defined in :rfc:`2342`, SORT, GETACL and
+  SETACL.  (Contributed by Anthony Baxter and Michel Pelletier.)
+
+* The :mod:`rfc822` module's parsing of email addresses is now compliant with
+  :rfc:`2822`, an update to :rfc:`822`.  (The module's name is *not* going to be
+  changed to ``rfc2822``.)  A new package, :mod:`email`, has also been added for
+  parsing and generating e-mail messages.  (Contributed by Barry Warsaw, and
+  arising out of his work on Mailman.)
+
+* The :mod:`difflib` module now contains a new :class:`Differ` class for
+  producing human-readable lists of changes (a "delta") between two sequences of
+  lines of text.  There are also two generator functions, :func:`ndiff` and
+  :func:`restore`, which respectively return a delta from two sequences, or one of
+  the original sequences from a delta. (Grunt work contributed by David Goodger,
+  from ndiff.py code by Tim Peters who then did the generatorization.)
+
+* New constants :const:`ascii_letters`, :const:`ascii_lowercase`, and
+  :const:`ascii_uppercase` were added to the :mod:`string` module.  There were
+  several modules in the standard library that used :const:`string.letters` to
+  mean the ranges A-Za-z, but that assumption is incorrect when locales are in
+  use, because :const:`string.letters` varies depending on the set of legal
+  characters defined by the current locale.  The buggy modules have all been fixed
+  to use :const:`ascii_letters` instead. (Reported by an unknown person; fixed by
+  Fred L. Drake, Jr.)
+
+* The :mod:`mimetypes` module now makes it easier to use alternative MIME-type
+  databases by the addition of a :class:`MimeTypes` class, which takes a list of
+  filenames to be parsed.  (Contributed by Fred L. Drake, Jr.)
+
+* A :class:`Timer` class was added to the :mod:`threading` module that allows
+  scheduling an activity to happen at some future time.  (Contributed by Itamar
+  Shtull-Trauring.)
+
+.. % ======================================================================
+
+
+Interpreter Changes and Fixes
+=============================
+
+Some of the changes only affect people who deal with the Python interpreter at
+the C level because they're writing Python extension modules, embedding the
+interpreter, or just hacking on the interpreter itself. If you only write Python
+code, none of the changes described here will affect you very much.
+
+* Profiling and tracing functions can now be implemented in C, which can operate
+  at much higher speeds than Python-based functions and should reduce the overhead
+  of profiling and tracing.  This  will be of interest to authors of development
+  environments for Python.  Two new C functions were added to Python's API,
+  :cfunc:`PyEval_SetProfile` and :cfunc:`PyEval_SetTrace`. The existing
+  :func:`sys.setprofile` and :func:`sys.settrace` functions still exist, and have
+  simply been changed to use the new C-level interface.  (Contributed by Fred L.
+  Drake, Jr.)
+
+* Another low-level API, primarily of interest to implementors of Python
+  debuggers and development tools, was added. :cfunc:`PyInterpreterState_Head` and
+  :cfunc:`PyInterpreterState_Next` let a caller walk through all the existing
+  interpreter objects; :cfunc:`PyInterpreterState_ThreadHead` and
+  :cfunc:`PyThreadState_Next` allow looping over all the thread states for a given
+  interpreter.  (Contributed by David Beazley.)
+
+* The C-level interface to the garbage collector has been changed to make it
+  easier to write extension types that support garbage collection and to debug
+  misuses of the functions. Various functions have slightly different semantics,
+  so a bunch of functions had to be renamed.  Extensions that use the old API will
+  still compile but will *not* participate in garbage collection, so updating them
+  for 2.2 should be considered fairly high priority.
+
+  To upgrade an extension module to the new API, perform the following steps:
+
+* Rename :cfunc:`Py_TPFLAGS_GC` to :cfunc:`PyTPFLAGS_HAVE_GC`.
+
+* Use :cfunc:`PyObject_GC_New` or :cfunc:`PyObject_GC_NewVar` to allocate
+    objects, and :cfunc:`PyObject_GC_Del` to deallocate them.
+
+* Rename :cfunc:`PyObject_GC_Init` to :cfunc:`PyObject_GC_Track` and
+    :cfunc:`PyObject_GC_Fini` to :cfunc:`PyObject_GC_UnTrack`.
+
+* Remove :cfunc:`PyGC_HEAD_SIZE` from object size calculations.
+
+* Remove calls to :cfunc:`PyObject_AS_GC` and :cfunc:`PyObject_FROM_GC`.
+
+* A new ``et`` format sequence was added to :cfunc:`PyArg_ParseTuple`; ``et``
+  takes both a parameter and an encoding name, and converts the parameter to the
+  given encoding if the parameter turns out to be a Unicode string, or leaves it
+  alone if it's an 8-bit string, assuming it to already be in the desired
+  encoding.  This differs from the ``es`` format character, which assumes that
+  8-bit strings are in Python's default ASCII encoding and converts them to the
+  specified new encoding. (Contributed by M.-A. Lemburg, and used for the MBCS
+  support on Windows described in the following section.)
+
+* A different argument parsing function, :cfunc:`PyArg_UnpackTuple`, has been
+  added that's simpler and presumably faster.  Instead of specifying a format
+  string, the caller simply gives the minimum and maximum number of arguments
+  expected, and a set of pointers to :ctype:`PyObject\*` variables that will be
+  filled in with argument values.
+
+* Two new flags :const:`METH_NOARGS` and :const:`METH_O` are available in method
+  definition tables to simplify implementation of methods with no arguments or a
+  single untyped argument. Calling such methods is more efficient than calling a
+  corresponding method that uses :const:`METH_VARARGS`.  Also, the old
+  :const:`METH_OLDARGS` style of writing C methods is  now officially deprecated.
+
+* Two new wrapper functions, :cfunc:`PyOS_snprintf` and :cfunc:`PyOS_vsnprintf`
+  were added to provide  cross-platform implementations for the relatively new
+  :cfunc:`snprintf` and :cfunc:`vsnprintf` C lib APIs. In contrast to the standard
+  :cfunc:`sprintf` and :cfunc:`vsprintf` functions, the Python versions check the
+  bounds of the buffer used to protect against buffer overruns. (Contributed by
+  M.-A. Lemburg.)
+
+* The :cfunc:`_PyTuple_Resize` function has lost an unused parameter, so now it
+  takes 2 parameters instead of 3.  The third argument was never used, and can
+  simply be discarded when porting code from earlier versions to Python 2.2.
+
+.. % ======================================================================
+
+
+Other Changes and Fixes
+=======================
+
+As usual there were a bunch of other improvements and bugfixes scattered
+throughout the source tree.  A search through the CVS change logs finds there
+were 527 patches applied and 683 bugs fixed between Python 2.1 and 2.2; 2.2.1
+applied 139 patches and fixed 143 bugs; 2.2.2 applied 106 patches and fixed 82
+bugs.  These figures are likely to be underestimates.
+
+Some of the more notable changes are:
+
+* The code for the MacOS port for Python, maintained by Jack Jansen, is now kept
+  in the main Python CVS tree, and many changes have been made to support MacOS X.
+
+  The most significant change is the ability to build Python as a framework,
+  enabled by supplying the :option:`--enable-framework` option to the configure
+  script when compiling Python.  According to Jack Jansen, "This installs a self-
+  contained Python installation plus the OS X framework "glue" into
+  :file:`/Library/Frameworks/Python.framework` (or another location of choice).
+  For now there is little immediate added benefit to this (actually, there is the
+  disadvantage that you have to change your PATH to be able to find Python), but
+  it is the basis for creating a full-blown Python application, porting the
+  MacPython IDE, possibly using Python as a standard OSA scripting language and
+  much more."
+
+  Most of the MacPython toolbox modules, which interface to MacOS APIs such as
+  windowing, QuickTime, scripting, etc. have been ported to OS X, but they've been
+  left commented out in :file:`setup.py`.  People who want to experiment with
+  these modules can uncomment them manually.
+
+  .. % Jack's original comments:
+  .. % The main change is the possibility to build Python as a
+  .. % framework. This installs a self-contained Python installation plus the
+  .. % OSX framework "glue" into /Library/Frameworks/Python.framework (or
+  .. % another location of choice). For now there is little immedeate added
+  .. % benefit to this (actually, there is the disadvantage that you have to
+  .. % change your PATH to be able to find Python), but it is the basis for
+  .. % creating a fullblown Python application, porting the MacPython IDE,
+  .. % possibly using Python as a standard OSA scripting language and much
+  .. % more. You enable this with "configure --enable-framework".
+  .. % The other change is that most MacPython toolbox modules, which
+  .. % interface to all the MacOS APIs such as windowing, quicktime,
+  .. % scripting, etc. have been ported. Again, most of these are not of
+  .. % immedeate use, as they need a full application to be really useful, so
+  .. % they have been commented out in setup.py. People wanting to experiment
+  .. % can uncomment them. Gestalt and Internet Config modules are enabled by
+  .. % default.
+
+* Keyword arguments passed to builtin functions that don't take them now cause a
+  :exc:`TypeError` exception to be raised, with the message "*function* takes no
+  keyword arguments".
+
+* Weak references, added in Python 2.1 as an extension module, are now part of
+  the core because they're used in the implementation of new-style classes.  The
+  :exc:`ReferenceError` exception has therefore moved from the :mod:`weakref`
+  module to become a built-in exception.
+
+* A new script, :file:`Tools/scripts/cleanfuture.py` by Tim Peters,
+  automatically removes obsolete ``__future__`` statements from Python source
+  code.
+
+* An additional *flags* argument has been added to the built-in function
+  :func:`compile`, so the behaviour of ``__future__`` statements can now be
+  correctly observed in simulated shells, such as those presented by IDLE and
+  other development environments.  This is described in :pep:`264`. (Contributed
+  by Michael Hudson.)
+
+* The new license introduced with Python 1.6 wasn't GPL-compatible.  This is
+  fixed by some minor textual changes to the 2.2 license, so it's now legal to
+  embed Python inside a GPLed program again.  Note that Python itself is not
+  GPLed, but instead is under a license that's essentially equivalent to the BSD
+  license, same as it always was.  The license changes were also applied to the
+  Python 2.0.1 and 2.1.1 releases.
+
+* When presented with a Unicode filename on Windows, Python will now convert it
+  to an MBCS encoded string, as used by the Microsoft file APIs.  As MBCS is
+  explicitly used by the file APIs, Python's choice of ASCII as the default
+  encoding turns out to be an annoyance.  On Unix, the locale's character set is
+  used if :func:`locale.nl_langinfo(CODESET)` is available.  (Windows support was
+  contributed by Mark Hammond with assistance from Marc-André Lemburg. Unix
+  support was added by Martin von Löwis.)
+
+* Large file support is now enabled on Windows.  (Contributed by Tim Peters.)
+
+* The :file:`Tools/scripts/ftpmirror.py` script now parses a :file:`.netrc`
+  file, if you have one. (Contributed by Mike Romberg.)
+
+* Some features of the object returned by the :func:`xrange` function are now
+  deprecated, and trigger warnings when they're accessed; they'll disappear in
+  Python 2.3. :class:`xrange` objects tried to pretend they were full sequence
+  types by supporting slicing, sequence multiplication, and the :keyword:`in`
+  operator, but these features were rarely used and therefore buggy.  The
+  :meth:`tolist` method and the :attr:`start`, :attr:`stop`, and :attr:`step`
+  attributes are also being deprecated.  At the C level, the fourth argument to
+  the :cfunc:`PyRange_New` function, ``repeat``, has also been deprecated.
+
+* There were a bunch of patches to the dictionary implementation, mostly to fix
+  potential core dumps if a dictionary contains objects that sneakily changed
+  their hash value, or mutated the dictionary they were contained in. For a while
+  python-dev fell into a gentle rhythm of Michael Hudson finding a case that
+  dumped core, Tim Peters fixing the bug, Michael finding another case, and round
+  and round it went.
+
+* On Windows, Python can now be compiled with Borland C thanks to a number of
+  patches contributed by Stephen Hansen, though the result isn't fully functional
+  yet.  (But this *is* progress...)
+
+* Another Windows enhancement: Wise Solutions generously offered PythonLabs use
+  of their InstallerMaster 8.1 system.  Earlier PythonLabs Windows installers used
+  Wise 5.0a, which was beginning to show its age.  (Packaged up by Tim Peters.)
+
+* Files ending in ``.pyw`` can now be imported on Windows. ``.pyw`` is a
+  Windows-only thing, used to indicate that a script needs to be run using
+  PYTHONW.EXE instead of PYTHON.EXE in order to prevent a DOS console from popping
+  up to display the output.  This patch makes it possible to import such scripts,
+  in case they're also usable as modules.  (Implemented by David Bolen.)
+
+* On platforms where Python uses the C :cfunc:`dlopen` function  to load
+  extension modules, it's now possible to set the flags used  by :cfunc:`dlopen`
+  using the :func:`sys.getdlopenflags` and :func:`sys.setdlopenflags` functions.
+  (Contributed by Bram Stolk.)
+
+* The :func:`pow` built-in function no longer supports 3 arguments when
+  floating-point numbers are supplied. ``pow(x, y, z)`` returns ``(x**y) % z``,
+  but this is never useful for floating point numbers, and the final result varies
+  unpredictably depending on the platform.  A call such as ``pow(2.0, 8.0, 7.0)``
+  will now raise a :exc:`TypeError` exception.
+
+.. % ======================================================================
+
+
+Acknowledgements
+================
+
+The author would like to thank the following people for offering suggestions,
+corrections and assistance with various drafts of this article: Fred Bremmer,
+Keith Briggs, Andrew Dalke, Fred L. Drake, Jr., Carel Fellinger, David Goodger,
+Mark Hammond, Stephen Hansen, Michael Hudson, Jack Jansen, Marc-André Lemburg,
+Martin von Löwis, Fredrik Lundh, Michael McLay, Nick Mathewson, Paul Moore,
+Gustavo Niemeyer, Don O'Donnell, Joonas Paalasma, Tim Peters, Jens Quade, Tom
+Reinhardt, Neil Schemenauer, Guido van Rossum, Greg Ward, Edward Welbourne.
+
diff --git a/Doc/whatsnew/2.3.rst b/Doc/whatsnew/2.3.rst
new file mode 100644
index 0000000..7dd4930
--- /dev/null
+++ b/Doc/whatsnew/2.3.rst
@@ -0,0 +1,2084 @@
+****************************
+  What's New in Python 2.3  
+****************************
+
+:Author: A.M. Kuchling
+
+.. |release| replace:: 1.01
+
+.. % $Id: whatsnew23.tex 55005 2007-04-27 19:54:29Z guido.van.rossum $
+
+This article explains the new features in Python 2.3.  Python 2.3 was released
+on July 29, 2003.
+
+The main themes for Python 2.3 are polishing some of the features added in 2.2,
+adding various small but useful enhancements to the core language, and expanding
+the standard library.  The new object model introduced in the previous version
+has benefited from 18 months of bugfixes and from optimization efforts that have
+improved the performance of new-style classes.  A few new built-in functions
+have been added such as :func:`sum` and :func:`enumerate`.  The :keyword:`in`
+operator can now be used for substring searches (e.g. ``"ab" in "abc"`` returns
+:const:`True`).
+
+Some of the many new library features include Boolean, set, heap, and date/time
+data types, the ability to import modules from ZIP-format archives, metadata
+support for the long-awaited Python catalog, an updated version of IDLE, and
+modules for logging messages, wrapping text, parsing CSV files, processing
+command-line options, using BerkeleyDB databases...  the list of new and
+enhanced modules is lengthy.
+
+This article doesn't attempt to provide a complete specification of the new
+features, but instead provides a convenient overview.  For full details, you
+should refer to the documentation for Python 2.3, such as the Python Library
+Reference and the Python Reference Manual.  If you want to understand the
+complete implementation and design rationale, refer to the PEP for a particular
+new feature.
+
+.. % ======================================================================
+
+
+PEP 218: A Standard Set Datatype
+================================
+
+The new :mod:`sets` module contains an implementation of a set datatype.  The
+:class:`Set` class is for mutable sets, sets that can have members added and
+removed.  The :class:`ImmutableSet` class is for sets that can't be modified,
+and instances of :class:`ImmutableSet` can therefore be used as dictionary keys.
+Sets are built on top of dictionaries, so the elements within a set must be
+hashable.
+
+Here's a simple example::
+
+   >>> import sets
+   >>> S = sets.Set([1,2,3])
+   >>> S
+   Set([1, 2, 3])
+   >>> 1 in S
+   True
+   >>> 0 in S
+   False
+   >>> S.add(5)
+   >>> S.remove(3)
+   >>> S
+   Set([1, 2, 5])
+   >>>
+
+The union and intersection of sets can be computed with the :meth:`union` and
+:meth:`intersection` methods; an alternative notation uses the bitwise operators
+``&`` and ``|``. Mutable sets also have in-place versions of these methods,
+:meth:`union_update` and :meth:`intersection_update`. ::
+
+   >>> S1 = sets.Set([1,2,3])
+   >>> S2 = sets.Set([4,5,6])
+   >>> S1.union(S2)
+   Set([1, 2, 3, 4, 5, 6])
+   >>> S1 | S2                  # Alternative notation
+   Set([1, 2, 3, 4, 5, 6])
+   >>> S1.intersection(S2)
+   Set([])
+   >>> S1 & S2                  # Alternative notation
+   Set([])
+   >>> S1.union_update(S2)
+   >>> S1
+   Set([1, 2, 3, 4, 5, 6])
+   >>>
+
+It's also possible to take the symmetric difference of two sets.  This is the
+set of all elements in the union that aren't in the intersection.  Another way
+of putting it is that the symmetric difference contains all elements that are in
+exactly one set.  Again, there's an alternative notation (``^``), and an in-
+place version with the ungainly name :meth:`symmetric_difference_update`. ::
+
+   >>> S1 = sets.Set([1,2,3,4])
+   >>> S2 = sets.Set([3,4,5,6])
+   >>> S1.symmetric_difference(S2)
+   Set([1, 2, 5, 6])
+   >>> S1 ^ S2
+   Set([1, 2, 5, 6])
+   >>>
+
+There are also :meth:`issubset` and :meth:`issuperset` methods for checking
+whether one set is a subset or superset of another::
+
+   >>> S1 = sets.Set([1,2,3])
+   >>> S2 = sets.Set([2,3])
+   >>> S2.issubset(S1)
+   True
+   >>> S1.issubset(S2)
+   False
+   >>> S1.issuperset(S2)
+   True
+   >>>
+
+
+.. seealso::
+
+   :pep:`218` - Adding a Built-In Set Object Type
+      PEP written by Greg V. Wilson. Implemented by Greg V. Wilson, Alex Martelli, and
+      GvR.
+
+.. % ======================================================================
+
+
+.. _section-generators:
+
+PEP 255: Simple Generators
+==========================
+
+In Python 2.2, generators were added as an optional feature, to be enabled by a
+``from __future__ import generators`` directive.  In 2.3 generators no longer
+need to be specially enabled, and are now always present; this means that
+:keyword:`yield` is now always a keyword.  The rest of this section is a copy of
+the description of generators from the "What's New in Python 2.2" document; if
+you read it back when Python 2.2 came out, you can skip the rest of this
+section.
+
+You're doubtless familiar with how function calls work in Python or C. When you
+call a function, it gets a private namespace where its local variables are
+created.  When the function reaches a :keyword:`return` statement, the local
+variables are destroyed and the resulting value is returned to the caller.  A
+later call to the same function will get a fresh new set of local variables.
+But, what if the local variables weren't thrown away on exiting a function?
+What if you could later resume the function where it left off?  This is what
+generators provide; they can be thought of as resumable functions.
+
+Here's the simplest example of a generator function::
+
+   def generate_ints(N):
+       for i in range(N):
+           yield i
+
+A new keyword, :keyword:`yield`, was introduced for generators.  Any function
+containing a :keyword:`yield` statement is a generator function; this is
+detected by Python's bytecode compiler which compiles the function specially as
+a result.
+
+When you call a generator function, it doesn't return a single value; instead it
+returns a generator object that supports the iterator protocol.  On executing
+the :keyword:`yield` statement, the generator outputs the value of ``i``,
+similar to a :keyword:`return` statement.  The big difference between
+:keyword:`yield` and a :keyword:`return` statement is that on reaching a
+:keyword:`yield` the generator's state of execution is suspended and local
+variables are preserved.  On the next call to the generator's ``.next()``
+method, the function will resume executing immediately after the
+:keyword:`yield` statement.  (For complicated reasons, the :keyword:`yield`
+statement isn't allowed inside the :keyword:`try` block of a :keyword:`try`...\
+:keyword:`finally` statement; read :pep:`255` for a full explanation of the
+interaction between :keyword:`yield` and exceptions.)
+
+Here's a sample usage of the :func:`generate_ints` generator::
+
+   >>> gen = generate_ints(3)
+   >>> gen
+   <generator object at 0x8117f90>
+   >>> gen.next()
+   0
+   >>> gen.next()
+   1
+   >>> gen.next()
+   2
+   >>> gen.next()
+   Traceback (most recent call last):
+     File "stdin", line 1, in ?
+     File "stdin", line 2, in generate_ints
+   StopIteration
+
+You could equally write ``for i in generate_ints(5)``, or ``a,b,c =
+generate_ints(3)``.
+
+Inside a generator function, the :keyword:`return` statement can only be used
+without a value, and signals the end of the procession of values; afterwards the
+generator cannot return any further values. :keyword:`return` with a value, such
+as ``return 5``, is a syntax error inside a generator function.  The end of the
+generator's results can also be indicated by raising :exc:`StopIteration`
+manually, or by just letting the flow of execution fall off the bottom of the
+function.
+
+You could achieve the effect of generators manually by writing your own class
+and storing all the local variables of the generator as instance variables.  For
+example, returning a list of integers could be done by setting ``self.count`` to
+0, and having the :meth:`next` method increment ``self.count`` and return it.
+However, for a moderately complicated generator, writing a corresponding class
+would be much messier. :file:`Lib/test/test_generators.py` contains a number of
+more interesting examples.  The simplest one implements an in-order traversal of
+a tree using generators recursively. ::
+
+   # A recursive generator that generates Tree leaves in in-order.
+   def inorder(t):
+       if t:
+           for x in inorder(t.left):
+               yield x
+           yield t.label
+           for x in inorder(t.right):
+               yield x
+
+Two other examples in :file:`Lib/test/test_generators.py` produce solutions for
+the N-Queens problem (placing $N$ queens on an $NxN$ chess board so that no
+queen threatens another) and the Knight's Tour (a route that takes a knight to
+every square of an $NxN$ chessboard without visiting any square twice).
+
+The idea of generators comes from other programming languages, especially Icon
+(http://www.cs.arizona.edu/icon/), where the idea of generators is central.  In
+Icon, every expression and function call behaves like a generator.  One example
+from "An Overview of the Icon Programming Language" at
+http://www.cs.arizona.edu/icon/docs/ipd266.htm gives an idea of what this looks
+like::
+
+   sentence := "Store it in the neighboring harbor"
+   if (i := find("or", sentence)) > 5 then write(i)
+
+In Icon the :func:`find` function returns the indexes at which the substring
+"or" is found: 3, 23, 33.  In the :keyword:`if` statement, ``i`` is first
+assigned a value of 3, but 3 is less than 5, so the comparison fails, and Icon
+retries it with the second value of 23.  23 is greater than 5, so the comparison
+now succeeds, and the code prints the value 23 to the screen.
+
+Python doesn't go nearly as far as Icon in adopting generators as a central
+concept.  Generators are considered part of the core Python language, but
+learning or using them isn't compulsory; if they don't solve any problems that
+you have, feel free to ignore them. One novel feature of Python's interface as
+compared to Icon's is that a generator's state is represented as a concrete
+object (the iterator) that can be passed around to other functions or stored in
+a data structure.
+
+
+.. seealso::
+
+   :pep:`255` - Simple Generators
+      Written by Neil Schemenauer, Tim Peters, Magnus Lie Hetland.  Implemented mostly
+      by Neil Schemenauer and Tim Peters, with other fixes from the Python Labs crew.
+
+.. % ======================================================================
+
+
+.. _section-encodings:
+
+PEP 263: Source Code Encodings
+==============================
+
+Python source files can now be declared as being in different character set
+encodings.  Encodings are declared by including a specially formatted comment in
+the first or second line of the source file.  For example, a UTF-8 file can be
+declared with::
+
+   #!/usr/bin/env python
+   # -*- coding: UTF-8 -*-
+
+Without such an encoding declaration, the default encoding used is 7-bit ASCII.
+Executing or importing modules that contain string literals with 8-bit
+characters and have no encoding declaration will result in a
+:exc:`DeprecationWarning` being signalled by Python 2.3; in 2.4 this will be a
+syntax error.
+
+The encoding declaration only affects Unicode string literals, which will be
+converted to Unicode using the specified encoding.  Note that Python identifiers
+are still restricted to ASCII characters, so you can't have variable names that
+use characters outside of the usual alphanumerics.
+
+
+.. seealso::
+
+   :pep:`263` - Defining Python Source Code Encodings
+      Written by Marc-André Lemburg and Martin von Löwis; implemented by Suzuki Hisao
+      and Martin von Löwis.
+
+.. % ======================================================================
+
+
+PEP 273: Importing Modules from ZIP Archives
+============================================
+
+The new :mod:`zipimport` module adds support for importing modules from a ZIP-
+format archive.  You don't need to import the module explicitly; it will be
+automatically imported if a ZIP archive's filename is added to ``sys.path``.
+For example::
+
+   amk@nyman:~/src/python$ unzip -l /tmp/example.zip
+   Archive:  /tmp/example.zip
+     Length     Date   Time    Name
+    --------    ----   ----    ----
+        8467  11-26-02 22:30   jwzthreading.py
+    --------                   -------
+        8467                   1 file
+   amk@nyman:~/src/python$ ./python
+   Python 2.3 (#1, Aug 1 2003, 19:54:32) 
+   >>> import sys
+   >>> sys.path.insert(0, '/tmp/example.zip')  # Add .zip file to front of path
+   >>> import jwzthreading
+   >>> jwzthreading.__file__
+   '/tmp/example.zip/jwzthreading.py'
+   >>>
+
+An entry in ``sys.path`` can now be the filename of a ZIP archive. The ZIP
+archive can contain any kind of files, but only files named :file:`\*.py`,
+:file:`\*.pyc`, or :file:`\*.pyo` can be imported.  If an archive only contains
+:file:`\*.py` files, Python will not attempt to modify the archive by adding the
+corresponding :file:`\*.pyc` file, meaning that if a ZIP archive doesn't contain
+:file:`\*.pyc` files, importing may be rather slow.
+
+A path within the archive can also be specified to only import from a
+subdirectory; for example, the path :file:`/tmp/example.zip/lib/` would only
+import from the :file:`lib/` subdirectory within the archive.
+
+
+.. seealso::
+
+   :pep:`273` - Import Modules from Zip Archives
+      Written by James C. Ahlstrom,  who also provided an implementation. Python 2.3
+      follows the specification in :pep:`273`,  but uses an implementation written by
+      Just van Rossum  that uses the import hooks described in :pep:`302`. See section
+      :ref:`section-pep302` for a description of the new import hooks.
+
+.. % ======================================================================
+
+
+PEP 277: Unicode file name support for Windows NT
+=================================================
+
+On Windows NT, 2000, and XP, the system stores file names as Unicode strings.
+Traditionally, Python has represented file names as byte strings, which is
+inadequate because it renders some file names inaccessible.
+
+Python now allows using arbitrary Unicode strings (within the limitations of the
+file system) for all functions that expect file names, most notably the
+:func:`open` built-in function. If a Unicode string is passed to
+:func:`os.listdir`, Python now returns a list of Unicode strings.  A new
+function, :func:`os.getcwdu`, returns the current directory as a Unicode string.
+
+Byte strings still work as file names, and on Windows Python will transparently
+convert them to Unicode using the ``mbcs`` encoding.
+
+Other systems also allow Unicode strings as file names but convert them to byte
+strings before passing them to the system, which can cause a :exc:`UnicodeError`
+to be raised. Applications can test whether arbitrary Unicode strings are
+supported as file names by checking :attr:`os.path.supports_unicode_filenames`,
+a Boolean value.
+
+Under MacOS, :func:`os.listdir` may now return Unicode filenames.
+
+
+.. seealso::
+
+   :pep:`277` - Unicode file name support for Windows NT
+      Written by Neil Hodgson; implemented by Neil Hodgson, Martin von Löwis, and Mark
+      Hammond.
+
+.. % ======================================================================
+
+
+PEP 278: Universal Newline Support
+==================================
+
+The three major operating systems used today are Microsoft Windows, Apple's
+Macintosh OS, and the various Unix derivatives.  A minor irritation of cross-
+platform work  is that these three platforms all use different characters to
+mark the ends of lines in text files.  Unix uses the linefeed (ASCII character
+10), MacOS uses the carriage return (ASCII character 13), and Windows uses a
+two-character sequence of a carriage return plus a newline.
+
+Python's file objects can now support end of line conventions other than the one
+followed by the platform on which Python is running. Opening a file with the
+mode ``'U'`` or ``'rU'`` will open a file for reading in universal newline mode.
+All three line ending conventions will be translated to a ``'\n'`` in the
+strings returned by the various file methods such as :meth:`read` and
+:meth:`readline`.
+
+Universal newline support is also used when importing modules and when executing
+a file with the :func:`execfile` function.  This means that Python modules can
+be shared between all three operating systems without needing to convert the
+line-endings.
+
+This feature can be disabled when compiling Python by specifying the
+:option:`--without-universal-newlines` switch when running Python's
+:program:`configure` script.
+
+
+.. seealso::
+
+   :pep:`278` - Universal Newline Support
+      Written and implemented by Jack Jansen.
+
+.. % ======================================================================
+
+
+.. _section-enumerate:
+
+PEP 279: enumerate()
+====================
+
+A new built-in function, :func:`enumerate`, will make certain loops a bit
+clearer.  ``enumerate(thing)``, where *thing* is either an iterator or a
+sequence, returns a iterator that will return ``(0, thing[0])``, ``(1,
+thing[1])``, ``(2, thing[2])``, and so forth.
+
+A common idiom to change every element of a list looks like this::
+
+   for i in range(len(L)):
+       item = L[i]
+       # ... compute some result based on item ...
+       L[i] = result
+
+This can be rewritten using :func:`enumerate` as::
+
+   for i, item in enumerate(L):
+       # ... compute some result based on item ...
+       L[i] = result
+
+
+.. seealso::
+
+   :pep:`279` - The enumerate() built-in function
+      Written and implemented by Raymond D. Hettinger.
+
+.. % ======================================================================
+
+
+PEP 282: The logging Package
+============================
+
+A standard package for writing logs, :mod:`logging`, has been added to Python
+2.3.  It provides a powerful and flexible mechanism for generating logging
+output which can then be filtered and processed in various ways.  A
+configuration file written in a standard format can be used to control the
+logging behavior of a program.  Python includes handlers that will write log
+records to standard error or to a file or socket, send them to the system log,
+or even e-mail them to a particular address; of course, it's also possible to
+write your own handler classes.
+
+The :class:`Logger` class is the primary class. Most application code will deal
+with one or more :class:`Logger` objects, each one used by a particular
+subsystem of the application. Each :class:`Logger` is identified by a name, and
+names are organized into a hierarchy using ``.``  as the component separator.
+For example, you might have :class:`Logger` instances named ``server``,
+``server.auth`` and ``server.network``.  The latter two instances are below
+``server`` in the hierarchy.  This means that if you turn up the verbosity for
+``server`` or direct ``server`` messages to a different handler, the changes
+will also apply to records logged to ``server.auth`` and ``server.network``.
+There's also a root :class:`Logger` that's the parent of all other loggers.
+
+For simple uses, the :mod:`logging` package contains some convenience functions
+that always use the root log::
+
+   import logging
+
+   logging.debug('Debugging information')
+   logging.info('Informational message')
+   logging.warning('Warning:config file %s not found', 'server.conf')
+   logging.error('Error occurred')
+   logging.critical('Critical error -- shutting down')
+
+This produces the following output::
+
+   WARNING:root:Warning:config file server.conf not found
+   ERROR:root:Error occurred
+   CRITICAL:root:Critical error -- shutting down
+
+In the default configuration, informational and debugging messages are
+suppressed and the output is sent to standard error.  You can enable the display
+of informational and debugging messages by calling the :meth:`setLevel` method
+on the root logger.
+
+Notice the :func:`warning` call's use of string formatting operators; all of the
+functions for logging messages take the arguments ``(msg, arg1, arg2, ...)`` and
+log the string resulting from ``msg % (arg1, arg2, ...)``.
+
+There's also an :func:`exception` function that records the most recent
+traceback.  Any of the other functions will also record the traceback if you
+specify a true value for the keyword argument *exc_info*. ::
+
+   def f():
+       try:    1/0
+       except: logging.exception('Problem recorded')
+
+   f()
+
+This produces the following output::
+
+   ERROR:root:Problem recorded
+   Traceback (most recent call last):
+     File "t.py", line 6, in f
+       1/0
+   ZeroDivisionError: integer division or modulo by zero
+
+Slightly more advanced programs will use a logger other than the root logger.
+The :func:`getLogger(name)` function is used to get a particular log, creating
+it if it doesn't exist yet. :func:`getLogger(None)` returns the root logger. ::
+
+   log = logging.getLogger('server')
+    ...
+   log.info('Listening on port %i', port)
+    ...
+   log.critical('Disk full')
+    ...
+
+Log records are usually propagated up the hierarchy, so a message logged to
+``server.auth`` is also seen by ``server`` and ``root``, but a :class:`Logger`
+can prevent this by setting its :attr:`propagate` attribute to :const:`False`.
+
+There are more classes provided by the :mod:`logging` package that can be
+customized.  When a :class:`Logger` instance is told to log a message, it
+creates a :class:`LogRecord` instance that is sent to any number of different
+:class:`Handler` instances.  Loggers and handlers can also have an attached list
+of filters, and each filter can cause the :class:`LogRecord` to be ignored or
+can modify the record before passing it along.  When they're finally output,
+:class:`LogRecord` instances are converted to text by a :class:`Formatter`
+class.  All of these classes can be replaced by your own specially-written
+classes.
+
+With all of these features the :mod:`logging` package should provide enough
+flexibility for even the most complicated applications.  This is only an
+incomplete overview of its features, so please see the package's reference
+documentation for all of the details.  Reading :pep:`282` will also be helpful.
+
+
+.. seealso::
+
+   :pep:`282` - A Logging System
+      Written by Vinay Sajip and Trent Mick; implemented by Vinay Sajip.
+
+.. % ======================================================================
+
+
+.. _section-bool:
+
+PEP 285: A Boolean Type
+=======================
+
+A Boolean type was added to Python 2.3.  Two new constants were added to the
+:mod:`__builtin__` module, :const:`True` and :const:`False`.  (:const:`True` and
+:const:`False` constants were added to the built-ins in Python 2.2.1, but the
+2.2.1 versions are simply set to integer values of 1 and 0 and aren't a
+different type.)
+
+The type object for this new type is named :class:`bool`; the constructor for it
+takes any Python value and converts it to :const:`True` or :const:`False`. ::
+
+   >>> bool(1)
+   True
+   >>> bool(0)
+   False
+   >>> bool([])
+   False
+   >>> bool( (1,) )
+   True
+
+Most of the standard library modules and built-in functions have been changed to
+return Booleans. ::
+
+   >>> obj = []
+   >>> hasattr(obj, 'append')
+   True
+   >>> isinstance(obj, list)
+   True
+   >>> isinstance(obj, tuple)
+   False
+
+Python's Booleans were added with the primary goal of making code clearer.  For
+example, if you're reading a function and encounter the statement ``return 1``,
+you might wonder whether the ``1`` represents a Boolean truth value, an index,
+or a coefficient that multiplies some other quantity.  If the statement is
+``return True``, however, the meaning of the return value is quite clear.
+
+Python's Booleans were *not* added for the sake of strict type-checking.  A very
+strict language such as Pascal would also prevent you performing arithmetic with
+Booleans, and would require that the expression in an :keyword:`if` statement
+always evaluate to a Boolean result.  Python is not this strict and never will
+be, as :pep:`285` explicitly says.  This means you can still use any expression
+in an :keyword:`if` statement, even ones that evaluate to a list or tuple or
+some random object.  The Boolean type is a subclass of the :class:`int` class so
+that arithmetic using a Boolean still works. ::
+
+   >>> True + 1
+   2
+   >>> False + 1
+   1
+   >>> False * 75
+   0
+   >>> True * 75
+   75
+
+To sum up :const:`True` and :const:`False` in a sentence: they're alternative
+ways to spell the integer values 1 and 0, with the single difference that
+:func:`str` and :func:`repr` return the strings ``'True'`` and ``'False'``
+instead of ``'1'`` and ``'0'``.
+
+
+.. seealso::
+
+   :pep:`285` - Adding a bool type
+      Written and implemented by GvR.
+
+.. % ======================================================================
+
+
+PEP 293: Codec Error Handling Callbacks
+=======================================
+
+When encoding a Unicode string into a byte string, unencodable characters may be
+encountered.  So far, Python has allowed specifying the error processing as
+either "strict" (raising :exc:`UnicodeError`), "ignore" (skipping the
+character), or "replace" (using a question mark in the output string), with
+"strict" being the default behavior. It may be desirable to specify alternative
+processing of such errors, such as inserting an XML character reference or HTML
+entity reference into the converted string.
+
+Python now has a flexible framework to add different processing strategies.  New
+error handlers can be added with :func:`codecs.register_error`, and codecs then
+can access the error handler with :func:`codecs.lookup_error`. An equivalent C
+API has been added for codecs written in C. The error handler gets the necessary
+state information such as the string being converted, the position in the string
+where the error was detected, and the target encoding.  The handler can then
+either raise an exception or return a replacement string.
+
+Two additional error handlers have been implemented using this framework:
+"backslashreplace" uses Python backslash quoting to represent unencodable
+characters and "xmlcharrefreplace" emits XML character references.
+
+
+.. seealso::
+
+   :pep:`293` - Codec Error Handling Callbacks
+      Written and implemented by Walter Dörwald.
+
+.. % ======================================================================
+
+
+.. _section-pep301:
+
+PEP 301: Package Index and Metadata for Distutils
+=================================================
+
+Support for the long-requested Python catalog makes its first appearance in 2.3.
+
+The heart of the catalog is the new Distutils :command:`register` command.
+Running ``python setup.py register`` will collect the metadata describing a
+package, such as its name, version, maintainer, description, &c., and send it to
+a central catalog server.  The resulting catalog is available from
+http://www.python.org/pypi.
+
+To make the catalog a bit more useful, a new optional *classifiers* keyword
+argument has been added to the Distutils :func:`setup` function.  A list of
+`Trove <http://catb.org/~esr/trove/>`_-style strings can be supplied to help
+classify the software.
+
+Here's an example :file:`setup.py` with classifiers, written to be compatible
+with older versions of the Distutils::
+
+   from distutils import core
+   kw = {'name': "Quixote",
+         'version': "0.5.1",
+         'description': "A highly Pythonic Web application framework",
+         # ...
+         }
+
+   if (hasattr(core, 'setup_keywords') and 
+       'classifiers' in core.setup_keywords):
+       kw['classifiers'] = \
+           ['Topic :: Internet :: WWW/HTTP :: Dynamic Content',
+            'Environment :: No Input/Output (Daemon)',
+            'Intended Audience :: Developers'],
+
+   core.setup(**kw)
+
+The full list of classifiers can be obtained by running  ``python setup.py
+register --list-classifiers``.
+
+
+.. seealso::
+
+   :pep:`301` - Package Index and Metadata for Distutils
+      Written and implemented by Richard Jones.
+
+.. % ======================================================================
+
+
+.. _section-pep302:
+
+PEP 302: New Import Hooks
+=========================
+
+While it's been possible to write custom import hooks ever since the
+:mod:`ihooks` module was introduced in Python 1.3, no one has ever been really
+happy with it because writing new import hooks is difficult and messy.  There
+have been various proposed alternatives such as the :mod:`imputil` and :mod:`iu`
+modules, but none of them has ever gained much acceptance, and none of them were
+easily usable from C code.
+
+:pep:`302` borrows ideas from its predecessors, especially from Gordon
+McMillan's :mod:`iu` module.  Three new items  are added to the :mod:`sys`
+module:
+
+* ``sys.path_hooks`` is a list of callable objects; most  often they'll be
+  classes.  Each callable takes a string containing a path and either returns an
+  importer object that will handle imports from this path or raises an
+  :exc:`ImportError` exception if it can't handle this path.
+
+* ``sys.path_importer_cache`` caches importer objects for each path, so
+  ``sys.path_hooks`` will only need to be traversed once for each path.
+
+* ``sys.meta_path`` is a list of importer objects that will be traversed before
+  ``sys.path`` is checked.  This list is initially empty, but user code can add
+  objects to it.  Additional built-in and frozen modules can be imported by an
+  object added to this list.
+
+Importer objects must have a single method, :meth:`find_module(fullname,
+path=None)`.  *fullname* will be a module or package name, e.g. ``string`` or
+``distutils.core``.  :meth:`find_module` must return a loader object that has a
+single method, :meth:`load_module(fullname)`, that creates and returns the
+corresponding module object.
+
+Pseudo-code for Python's new import logic, therefore, looks something like this
+(simplified a bit; see :pep:`302` for the full details)::
+
+   for mp in sys.meta_path:
+       loader = mp(fullname)
+       if loader is not None:
+           <module> = loader.load_module(fullname)
+
+   for path in sys.path:
+       for hook in sys.path_hooks:
+           try:
+               importer = hook(path)
+           except ImportError:
+               # ImportError, so try the other path hooks
+               pass
+           else:
+               loader = importer.find_module(fullname)
+               <module> = loader.load_module(fullname)
+
+   # Not found!
+   raise ImportError
+
+
+.. seealso::
+
+   :pep:`302` - New Import Hooks
+      Written by Just van Rossum and Paul Moore. Implemented by Just van Rossum.
+
+.. % ======================================================================
+
+
+.. _section-pep305:
+
+PEP 305: Comma-separated Files
+==============================
+
+Comma-separated files are a format frequently used for exporting data from
+databases and spreadsheets.  Python 2.3 adds a parser for comma-separated files.
+
+Comma-separated format is deceptively simple at first glance::
+
+   Costs,150,200,3.95
+
+Read a line and call ``line.split(',')``: what could be simpler? But toss in
+string data that can contain commas, and things get more complicated::
+
+   "Costs",150,200,3.95,"Includes taxes, shipping, and sundry items"
+
+A big ugly regular expression can parse this, but using the new  :mod:`csv`
+package is much simpler::
+
+   import csv
+
+   input = open('datafile', 'rb')
+   reader = csv.reader(input)
+   for line in reader:
+       print line
+
+The :func:`reader` function takes a number of different options. The field
+separator isn't limited to the comma and can be changed to any character, and so
+can the quoting and line-ending characters.
+
+Different dialects of comma-separated files can be defined and registered;
+currently there are two dialects, both used by Microsoft Excel. A separate
+:class:`csv.writer` class will generate comma-separated files from a succession
+of tuples or lists, quoting strings that contain the delimiter.
+
+
+.. seealso::
+
+   :pep:`305` - CSV File API
+      Written and implemented  by Kevin Altis, Dave Cole, Andrew McNamara, Skip
+      Montanaro, Cliff Wells.
+
+.. % ======================================================================
+
+
+.. _section-pep307:
+
+PEP 307: Pickle Enhancements
+============================
+
+The :mod:`pickle` and :mod:`cPickle` modules received some attention during the
+2.3 development cycle.  In 2.2, new-style classes could be pickled without
+difficulty, but they weren't pickled very compactly; :pep:`307` quotes a trivial
+example where a new-style class results in a pickled string three times longer
+than that for a classic class.
+
+The solution was to invent a new pickle protocol.  The :func:`pickle.dumps`
+function has supported a text-or-binary flag  for a long time.  In 2.3, this
+flag is redefined from a Boolean to an integer: 0 is the old text-mode pickle
+format, 1 is the old binary format, and now 2 is a new 2.3-specific format.  A
+new constant, :const:`pickle.HIGHEST_PROTOCOL`, can be used to select the
+fanciest protocol available.
+
+Unpickling is no longer considered a safe operation.  2.2's :mod:`pickle`
+provided hooks for trying to prevent unsafe classes from being unpickled
+(specifically, a :attr:`__safe_for_unpickling__` attribute), but none of this
+code was ever audited and therefore it's all been ripped out in 2.3.  You should
+not unpickle untrusted data in any version of Python.
+
+To reduce the pickling overhead for new-style classes, a new interface for
+customizing pickling was added using three special methods:
+:meth:`__getstate__`, :meth:`__setstate__`, and :meth:`__getnewargs__`.  Consult
+:pep:`307` for the full semantics  of these methods.
+
+As a way to compress pickles yet further, it's now possible to use integer codes
+instead of long strings to identify pickled classes. The Python Software
+Foundation will maintain a list of standardized codes; there's also a range of
+codes for private use.  Currently no codes have been specified.
+
+
+.. seealso::
+
+   :pep:`307` - Extensions to the pickle protocol
+      Written and implemented  by Guido van Rossum and Tim Peters.
+
+.. % ======================================================================
+
+
+.. _section-slices:
+
+Extended Slices
+===============
+
+Ever since Python 1.4, the slicing syntax has supported an optional third "step"
+or "stride" argument.  For example, these are all legal Python syntax:
+``L[1:10:2]``, ``L[:-1:1]``, ``L[::-1]``.  This was added to Python at the
+request of the developers of Numerical Python, which uses the third argument
+extensively.  However, Python's built-in list, tuple, and string sequence types
+have never supported this feature, raising a :exc:`TypeError` if you tried it.
+Michael Hudson contributed a patch to fix this shortcoming.
+
+For example, you can now easily extract the elements of a list that have even
+indexes::
+
+   >>> L = range(10)
+   >>> L[::2]
+   [0, 2, 4, 6, 8]
+
+Negative values also work to make a copy of the same list in reverse order::
+
+   >>> L[::-1]
+   [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
+
+This also works for tuples, arrays, and strings::
+
+   >>> s='abcd'
+   >>> s[::2]
+   'ac'
+   >>> s[::-1]
+   'dcba'
+
+If you have a mutable sequence such as a list or an array you can assign to or
+delete an extended slice, but there are some differences between assignment to
+extended and regular slices.  Assignment to a regular slice can be used to
+change the length of the sequence::
+
+   >>> a = range(3)
+   >>> a
+   [0, 1, 2]
+   >>> a[1:3] = [4, 5, 6]
+   >>> a
+   [0, 4, 5, 6]
+
+Extended slices aren't this flexible.  When assigning to an extended slice, the
+list on the right hand side of the statement must contain the same number of
+items as the slice it is replacing::
+
+   >>> a = range(4)
+   >>> a
+   [0, 1, 2, 3]
+   >>> a[::2]
+   [0, 2]
+   >>> a[::2] = [0, -1]
+   >>> a
+   [0, 1, -1, 3]
+   >>> a[::2] = [0,1,2]
+   Traceback (most recent call last):
+     File "<stdin>", line 1, in ?
+   ValueError: attempt to assign sequence of size 3 to extended slice of size 2
+
+Deletion is more straightforward::
+
+   >>> a = range(4)
+   >>> a
+   [0, 1, 2, 3]
+   >>> a[::2]
+   [0, 2]
+   >>> del a[::2]
+   >>> a
+   [1, 3]
+
+One can also now pass slice objects to the :meth:`__getitem__` methods of the
+built-in sequences::
+
+   >>> range(10).__getitem__(slice(0, 5, 2))
+   [0, 2, 4]
+
+Or use slice objects directly in subscripts::
+
+   >>> range(10)[slice(0, 5, 2)]
+   [0, 2, 4]
+
+To simplify implementing sequences that support extended slicing, slice objects
+now have a method :meth:`indices(length)` which, given the length of a sequence,
+returns a ``(start, stop, step)`` tuple that can be passed directly to
+:func:`range`. :meth:`indices` handles omitted and out-of-bounds indices in a
+manner consistent with regular slices (and this innocuous phrase hides a welter
+of confusing details!).  The method is intended to be used like this::
+
+   class FakeSeq:
+       ...
+       def calc_item(self, i):
+           ...
+       def __getitem__(self, item):
+           if isinstance(item, slice):
+               indices = item.indices(len(self))
+               return FakeSeq([self.calc_item(i) for i in range(*indices)])
+           else:
+               return self.calc_item(i)
+
+From this example you can also see that the built-in :class:`slice` object is
+now the type object for the slice type, and is no longer a function.  This is
+consistent with Python 2.2, where :class:`int`, :class:`str`, etc., underwent
+the same change.
+
+.. % ======================================================================
+
+
+Other Language Changes
+======================
+
+Here are all of the changes that Python 2.3 makes to the core Python language.
+
+* The :keyword:`yield` statement is now always a keyword, as described in
+  section :ref:`section-generators` of this document.
+
+* A new built-in function :func:`enumerate` was added, as described in section
+  :ref:`section-enumerate` of this document.
+
+* Two new constants, :const:`True` and :const:`False` were added along with the
+  built-in :class:`bool` type, as described in section :ref:`section-bool` of this
+  document.
+
+* The :func:`int` type constructor will now return a long integer instead of
+  raising an :exc:`OverflowError` when a string or floating-point number is too
+  large to fit into an integer.  This can lead to the paradoxical result that
+  ``isinstance(int(expression), int)`` is false, but that seems unlikely to cause
+  problems in practice.
+
+* Built-in types now support the extended slicing syntax, as described in
+  section :ref:`section-slices` of this document.
+
+* A new built-in function, :func:`sum(iterable, start=0)`,  adds up the numeric
+  items in the iterable object and returns their sum.  :func:`sum` only accepts
+  numbers, meaning that you can't use it to concatenate a bunch of strings.
+  (Contributed by Alex Martelli.)
+
+* ``list.insert(pos, value)`` used to  insert *value* at the front of the list
+  when *pos* was negative.  The behaviour has now been changed to be consistent
+  with slice indexing, so when *pos* is -1 the value will be inserted before the
+  last element, and so forth.
+
+* ``list.index(value)``, which searches for *value*  within the list and returns
+  its index, now takes optional  *start* and *stop* arguments to limit the search
+  to  only part of the list.
+
+* Dictionaries have a new method, :meth:`pop(key[, *default*])`, that returns
+  the value corresponding to *key* and removes that key/value pair from the
+  dictionary.  If the requested key isn't present in the dictionary, *default* is
+  returned if it's specified and :exc:`KeyError` raised if it isn't. ::
+
+     >>> d = {1:2}
+     >>> d
+     {1: 2}
+     >>> d.pop(4)
+     Traceback (most recent call last):
+       File "stdin", line 1, in ?
+     KeyError: 4
+     >>> d.pop(1)
+     2
+     >>> d.pop(1)
+     Traceback (most recent call last):
+       File "stdin", line 1, in ?
+     KeyError: 'pop(): dictionary is empty'
+     >>> d
+     {}
+     >>>
+
+  There's also a new class method,  :meth:`dict.fromkeys(iterable, value)`, that
+  creates a dictionary with keys taken from the supplied iterator *iterable* and
+  all values set to *value*, defaulting to ``None``.
+
+  (Patches contributed by Raymond Hettinger.)
+
+  Also, the :func:`dict` constructor now accepts keyword arguments to simplify
+  creating small dictionaries::
+
+     >>> dict(red=1, blue=2, green=3, black=4)
+     {'blue': 2, 'black': 4, 'green': 3, 'red': 1}    
+
+  (Contributed by Just van Rossum.)
+
+* The :keyword:`assert` statement no longer checks the ``__debug__`` flag, so
+  you can no longer disable assertions by assigning to ``__debug__``. Running
+  Python with the :option:`-O` switch will still generate code that doesn't
+  execute any assertions.
+
+* Most type objects are now callable, so you can use them to create new objects
+  such as functions, classes, and modules.  (This means that the :mod:`new` module
+  can be deprecated in a future Python version, because you can now use the type
+  objects available in the :mod:`types` module.) For example, you can create a new
+  module object with the following code:
+
+  .. % XXX should new.py use PendingDeprecationWarning?
+
+  ::
+
+     >>> import types
+     >>> m = types.ModuleType('abc','docstring')
+     >>> m
+     <module 'abc' (built-in)>
+     >>> m.__doc__
+     'docstring'
+
+* A new warning, :exc:`PendingDeprecationWarning` was added to indicate features
+  which are in the process of being deprecated.  The warning will *not* be printed
+  by default.  To check for use of features that will be deprecated in the future,
+  supply :option:`-Walways::PendingDeprecationWarning::` on the command line or
+  use :func:`warnings.filterwarnings`.
+
+* The process of deprecating string-based exceptions, as in ``raise "Error
+  occurred"``, has begun.  Raising a string will now trigger
+  :exc:`PendingDeprecationWarning`.
+
+* Using ``None`` as a variable name will now result in a :exc:`SyntaxWarning`
+  warning.  In a future version of Python, ``None`` may finally become a keyword.
+
+* The :meth:`xreadlines` method of file objects, introduced in Python 2.1, is no
+  longer necessary because files now behave as their own iterator.
+  :meth:`xreadlines` was originally introduced as a faster way to loop over all
+  the lines in a file, but now you can simply write ``for line in file_obj``.
+  File objects also have a new read-only :attr:`encoding` attribute that gives the
+  encoding used by the file; Unicode strings written to the file will be
+  automatically  converted to bytes using the given encoding.
+
+* The method resolution order used by new-style classes has changed, though
+  you'll only notice the difference if you have a really complicated inheritance
+  hierarchy.  Classic classes are unaffected by this change.  Python 2.2
+  originally used a topological sort of a class's ancestors, but 2.3 now uses the
+  C3 algorithm as described in the paper `"A Monotonic Superclass Linearization
+  for Dylan" <http://www.webcom.com/haahr/dylan/linearization-oopsla96.html>`_. To
+  understand the motivation for this change,  read Michele Simionato's article
+  `"Python 2.3 Method Resolution Order" <http://www.python.org/2.3/mro.html>`_, or
+  read the thread on python-dev starting with the message at
+  http://mail.python.org/pipermail/python-dev/2002-October/029035.html. Samuele
+  Pedroni first pointed out the problem and also implemented the fix by coding the
+  C3 algorithm.
+
+* Python runs multithreaded programs by switching between threads after
+  executing N bytecodes.  The default value for N has been increased from 10 to
+  100 bytecodes, speeding up single-threaded applications by reducing the
+  switching overhead.  Some multithreaded applications may suffer slower response
+  time, but that's easily fixed by setting the limit back to a lower number using
+  :func:`sys.setcheckinterval(N)`. The limit can be retrieved with the new
+  :func:`sys.getcheckinterval` function.
+
+* One minor but far-reaching change is that the names of extension types defined
+  by the modules included with Python now contain the module and a ``'.'`` in
+  front of the type name.  For example, in Python 2.2, if you created a socket and
+  printed its :attr:`__class__`, you'd get this output::
+
+     >>> s = socket.socket()
+     >>> s.__class__
+     <type 'socket'>
+
+  In 2.3, you get this::
+
+     >>> s.__class__
+     <type '_socket.socket'>
+
+* One of the noted incompatibilities between old- and new-style classes has been
+  removed: you can now assign to the :attr:`__name__` and :attr:`__bases__`
+  attributes of new-style classes.  There are some restrictions on what can be
+  assigned to :attr:`__bases__` along the lines of those relating to assigning to
+  an instance's :attr:`__class__` attribute.
+
+.. % ======================================================================
+
+
+String Changes
+--------------
+
+* The :keyword:`in` operator now works differently for strings. Previously, when
+  evaluating ``X in Y`` where *X* and *Y* are strings, *X* could only be a single
+  character. That's now changed; *X* can be a string of any length, and ``X in Y``
+  will return :const:`True` if *X* is a substring of *Y*.  If *X* is the empty
+  string, the result is always :const:`True`. ::
+
+     >>> 'ab' in 'abcd'
+     True
+     >>> 'ad' in 'abcd'
+     False
+     >>> '' in 'abcd'
+     True
+
+  Note that this doesn't tell you where the substring starts; if you need that
+  information, use the :meth:`find` string method.
+
+* The :meth:`strip`, :meth:`lstrip`, and :meth:`rstrip` string methods now have
+  an optional argument for specifying the characters to strip.  The default is
+  still to remove all whitespace characters::
+
+     >>> '   abc '.strip()
+     'abc'
+     >>> '><><abc<><><>'.strip('<>')
+     'abc'
+     >>> '><><abc<><><>\n'.strip('<>')
+     'abc<><><>\n'
+     >>> u'\u4000\u4001abc\u4000'.strip(u'\u4000')
+     u'\u4001abc'
+     >>>
+
+  (Suggested by Simon Brunning and implemented by Walter Dörwald.)
+
+* The :meth:`startswith` and :meth:`endswith` string methods now accept negative
+  numbers for the *start* and *end* parameters.
+
+* Another new string method is :meth:`zfill`, originally a function in the
+  :mod:`string` module.  :meth:`zfill` pads a numeric string with zeros on the
+  left until it's the specified width. Note that the ``%`` operator is still more
+  flexible and powerful than :meth:`zfill`. ::
+
+     >>> '45'.zfill(4)
+     '0045'
+     >>> '12345'.zfill(4)
+     '12345'
+     >>> 'goofy'.zfill(6)
+     '0goofy'
+
+  (Contributed by Walter Dörwald.)
+
+* A new type object, :class:`basestring`, has been added. Both 8-bit strings and
+  Unicode strings inherit from this type, so ``isinstance(obj, basestring)`` will
+  return :const:`True` for either kind of string.  It's a completely abstract
+  type, so you can't create :class:`basestring` instances.
+
+* Interned strings are no longer immortal and will now be garbage-collected in
+  the usual way when the only reference to them is from the internal dictionary of
+  interned strings.  (Implemented by Oren Tirosh.)
+
+.. % ======================================================================
+
+
+Optimizations
+-------------
+
+* The creation of new-style class instances has been made much faster; they're
+  now faster than classic classes!
+
+* The :meth:`sort` method of list objects has been extensively rewritten by Tim
+  Peters, and the implementation is significantly faster.
+
+* Multiplication of large long integers is now much faster thanks to an
+  implementation of Karatsuba multiplication, an algorithm that scales better than
+  the O(n\*n) required for the grade-school multiplication algorithm.  (Original
+  patch by Christopher A. Craig, and significantly reworked by Tim Peters.)
+
+* The ``SET_LINENO`` opcode is now gone.  This may provide a small speed
+  increase, depending on your compiler's idiosyncrasies. See section
+  :ref:`section-other` for a longer explanation. (Removed by Michael Hudson.)
+
+* :func:`xrange` objects now have their own iterator, making ``for i in
+  xrange(n)`` slightly faster than ``for i in range(n)``.  (Patch by Raymond
+  Hettinger.)
+
+* A number of small rearrangements have been made in various hotspots to improve
+  performance, such as inlining a function or removing some code.  (Implemented
+  mostly by GvR, but lots of people have contributed single changes.)
+
+The net result of the 2.3 optimizations is that Python 2.3 runs the  pystone
+benchmark around 25% faster than Python 2.2.
+
+.. % ======================================================================
+
+
+New, Improved, and Deprecated Modules
+=====================================
+
+As usual, Python's standard library received a number of enhancements and bug
+fixes.  Here's a partial list of the most notable changes, sorted alphabetically
+by module name. Consult the :file:`Misc/NEWS` file in the source tree for a more
+complete list of changes, or look through the CVS logs for all the details.
+
+* The :mod:`array` module now supports arrays of Unicode characters using the
+  ``'u'`` format character.  Arrays also now support using the ``+=`` assignment
+  operator to add another array's contents, and the ``*=`` assignment operator to
+  repeat an array. (Contributed by Jason Orendorff.)
+
+* The :mod:`bsddb` module has been replaced by version 4.1.6 of the `PyBSDDB
+  <http://pybsddb.sourceforge.net>`_ package, providing a more complete interface
+  to the transactional features of the BerkeleyDB library.
+
+  The old version of the module has been renamed to  :mod:`bsddb185` and is no
+  longer built automatically; you'll  have to edit :file:`Modules/Setup` to enable
+  it.  Note that the new :mod:`bsddb` package is intended to be compatible with
+  the  old module, so be sure to file bugs if you discover any incompatibilities.
+  When upgrading to Python 2.3, if the new interpreter is compiled with a new
+  version of  the underlying BerkeleyDB library, you will almost certainly have to
+  convert your database files to the new version.  You can do this fairly easily
+  with the new scripts :file:`db2pickle.py` and :file:`pickle2db.py` which you
+  will find in the distribution's :file:`Tools/scripts` directory.  If you've
+  already been using the PyBSDDB package and importing it as :mod:`bsddb3`, you
+  will have to change your ``import`` statements to import it as :mod:`bsddb`.
+
+* The new :mod:`bz2` module is an interface to the bz2 data compression library.
+  bz2-compressed data is usually smaller than  corresponding :mod:`zlib`\
+  -compressed data. (Contributed by Gustavo Niemeyer.)
+
+* A set of standard date/time types has been added in the new :mod:`datetime`
+  module.  See the following section for more details.
+
+* The Distutils :class:`Extension` class now supports an extra constructor
+  argument named *depends* for listing additional source files that an extension
+  depends on.  This lets Distutils recompile the module if any of the dependency
+  files are modified.  For example, if :file:`sampmodule.c` includes the header
+  file :file:`sample.h`, you would create the :class:`Extension` object like
+  this::
+
+     ext = Extension("samp",
+                     sources=["sampmodule.c"],
+                     depends=["sample.h"])
+
+  Modifying :file:`sample.h` would then cause the module to be recompiled.
+  (Contributed by Jeremy Hylton.)
+
+* Other minor changes to Distutils: it now checks for the :envvar:`CC`,
+  :envvar:`CFLAGS`, :envvar:`CPP`, :envvar:`LDFLAGS`, and :envvar:`CPPFLAGS`
+  environment variables, using them to override the settings in Python's
+  configuration (contributed by Robert Weber).
+
+* Previously the :mod:`doctest` module would only search the docstrings of
+  public methods and functions for test cases, but it now also examines private
+  ones as well.  The :func:`DocTestSuite(` function creates a
+  :class:`unittest.TestSuite` object from a set of :mod:`doctest` tests.
+
+* The new :func:`gc.get_referents(object)` function returns a list of all the
+  objects referenced by *object*.
+
+* The :mod:`getopt` module gained a new function, :func:`gnu_getopt`, that
+  supports the same arguments as the existing :func:`getopt` function but uses
+  GNU-style scanning mode. The existing :func:`getopt` stops processing options as
+  soon as a non-option argument is encountered, but in GNU-style mode processing
+  continues, meaning that options and arguments can be mixed.  For example::
+
+     >>> getopt.getopt(['-f', 'filename', 'output', '-v'], 'f:v')
+     ([('-f', 'filename')], ['output', '-v'])
+     >>> getopt.gnu_getopt(['-f', 'filename', 'output', '-v'], 'f:v')
+     ([('-f', 'filename'), ('-v', '')], ['output'])
+
+  (Contributed by Peter Åstrand.)
+
+* The :mod:`grp`, :mod:`pwd`, and :mod:`resource` modules now return enhanced
+  tuples::
+
+     >>> import grp
+     >>> g = grp.getgrnam('amk')
+     >>> g.gr_name, g.gr_gid
+     ('amk', 500)
+
+* The :mod:`gzip` module can now handle files exceeding 2 GiB.
+
+* The new :mod:`heapq` module contains an implementation of a heap queue
+  algorithm.  A heap is an array-like data structure that keeps items in a
+  partially sorted order such that, for every index *k*, ``heap[k] <=
+  heap[2*k+1]`` and ``heap[k] <= heap[2*k+2]``.  This makes it quick to remove the
+  smallest item, and inserting a new item while maintaining the heap property is
+  O(lg n).  (See http://www.nist.gov/dads/HTML/priorityque.html for more
+  information about the priority queue data structure.)
+
+  The :mod:`heapq` module provides :func:`heappush` and :func:`heappop` functions
+  for adding and removing items while maintaining the heap property on top of some
+  other mutable Python sequence type.  Here's an example that uses a Python list::
+
+     >>> import heapq
+     >>> heap = []
+     >>> for item in [3, 7, 5, 11, 1]:
+     ...    heapq.heappush(heap, item)
+     ...
+     >>> heap
+     [1, 3, 5, 11, 7]
+     >>> heapq.heappop(heap)
+     1
+     >>> heapq.heappop(heap)
+     3
+     >>> heap
+     [5, 7, 11]
+
+  (Contributed by Kevin O'Connor.)
+
+* The IDLE integrated development environment has been updated using the code
+  from the IDLEfork project (http://idlefork.sf.net).  The most notable feature is
+  that the code being developed is now executed in a subprocess, meaning that
+  there's no longer any need for manual ``reload()`` operations. IDLE's core code
+  has been incorporated into the standard library as the :mod:`idlelib` package.
+
+* The :mod:`imaplib` module now supports IMAP over SSL. (Contributed by Piers
+  Lauder and Tino Lange.)
+
+* The :mod:`itertools` contains a number of useful functions for use with
+  iterators, inspired by various functions provided by the ML and Haskell
+  languages.  For example, ``itertools.ifilter(predicate, iterator)`` returns all
+  elements in the iterator for which the function :func:`predicate` returns
+  :const:`True`, and ``itertools.repeat(obj, N)`` returns ``obj`` *N* times.
+  There are a number of other functions in the module; see the package's reference
+  documentation for details.
+  (Contributed by Raymond Hettinger.)
+
+* Two new functions in the :mod:`math` module, :func:`degrees(rads)` and
+  :func:`radians(degs)`, convert between radians and degrees.  Other functions in
+  the :mod:`math` module such as :func:`math.sin` and :func:`math.cos` have always
+  required input values measured in radians.  Also, an optional *base* argument
+  was added to :func:`math.log` to make it easier to compute logarithms for bases
+  other than ``e`` and ``10``.  (Contributed by Raymond Hettinger.)
+
+* Several new POSIX functions (:func:`getpgid`, :func:`killpg`, :func:`lchown`,
+  :func:`loadavg`, :func:`major`, :func:`makedev`, :func:`minor`, and
+  :func:`mknod`) were added to the :mod:`posix` module that underlies the
+  :mod:`os` module. (Contributed by Gustavo Niemeyer, Geert Jansen, and Denis S.
+  Otkidach.)
+
+* In the :mod:`os` module, the :func:`\*stat` family of functions can now report
+  fractions of a second in a timestamp.  Such time stamps are represented as
+  floats, similar to the value returned by :func:`time.time`.
+
+  During testing, it was found that some applications will break if time stamps
+  are floats.  For compatibility, when using the tuple interface of the
+  :class:`stat_result` time stamps will be represented as integers. When using
+  named fields (a feature first introduced in Python 2.2), time stamps are still
+  represented as integers, unless :func:`os.stat_float_times` is invoked to enable
+  float return values::
+
+     >>> os.stat("/tmp").st_mtime
+     1034791200
+     >>> os.stat_float_times(True)
+     >>> os.stat("/tmp").st_mtime
+     1034791200.6335014
+
+  In Python 2.4, the default will change to always returning floats.
+
+  Application developers should enable this feature only if all their libraries
+  work properly when confronted with floating point time stamps, or if they use
+  the tuple API. If used, the feature should be activated on an application level
+  instead of trying to enable it on a per-use basis.
+
+* The :mod:`optparse` module contains a new parser for command-line arguments
+  that can convert option values to a particular Python type  and will
+  automatically generate a usage message.  See the following section for  more
+  details.
+
+* The old and never-documented :mod:`linuxaudiodev` module has been deprecated,
+  and a new version named :mod:`ossaudiodev` has been added.  The module was
+  renamed because the OSS sound drivers can be used on platforms other than Linux,
+  and the interface has also been tidied and brought up to date in various ways.
+  (Contributed by Greg Ward and Nicholas FitzRoy-Dale.)
+
+* The new :mod:`platform` module contains a number of functions that try to
+  determine various properties of the platform you're running on.  There are
+  functions for getting the architecture, CPU type, the Windows OS version, and
+  even the Linux distribution version. (Contributed by Marc-André Lemburg.)
+
+* The parser objects provided by the :mod:`pyexpat` module can now optionally
+  buffer character data, resulting in fewer calls to your character data handler
+  and therefore faster performance.  Setting the parser object's
+  :attr:`buffer_text` attribute to :const:`True` will enable buffering.
+
+* The :func:`sample(population, k)` function was added to the :mod:`random`
+  module.  *population* is a sequence or :class:`xrange` object containing the
+  elements of a population, and :func:`sample` chooses *k* elements from the
+  population without replacing chosen elements.  *k* can be any value up to
+  ``len(population)``. For example::
+
+     >>> days = ['Mo', 'Tu', 'We', 'Th', 'Fr', 'St', 'Sn']
+     >>> random.sample(days, 3)      # Choose 3 elements
+     ['St', 'Sn', 'Th']
+     >>> random.sample(days, 7)      # Choose 7 elements
+     ['Tu', 'Th', 'Mo', 'We', 'St', 'Fr', 'Sn']
+     >>> random.sample(days, 7)      # Choose 7 again
+     ['We', 'Mo', 'Sn', 'Fr', 'Tu', 'St', 'Th']
+     >>> random.sample(days, 8)      # Can't choose eight
+     Traceback (most recent call last):
+       File "<stdin>", line 1, in ?
+       File "random.py", line 414, in sample
+           raise ValueError, "sample larger than population"
+     ValueError: sample larger than population
+     >>> random.sample(xrange(1,10000,2), 10)   # Choose ten odd nos. under 10000
+     [3407, 3805, 1505, 7023, 2401, 2267, 9733, 3151, 8083, 9195]
+
+  The :mod:`random` module now uses a new algorithm, the Mersenne Twister,
+  implemented in C.  It's faster and more extensively studied than the previous
+  algorithm.
+
+  (All changes contributed by Raymond Hettinger.)
+
+* The :mod:`readline` module also gained a number of new functions:
+  :func:`get_history_item`, :func:`get_current_history_length`, and
+  :func:`redisplay`.
+
+* The :mod:`rexec` and :mod:`Bastion` modules have been declared dead, and
+  attempts to import them will fail with a :exc:`RuntimeError`.  New-style classes
+  provide new ways to break out of the restricted execution environment provided
+  by :mod:`rexec`, and no one has interest in fixing them or time to do so.  If
+  you have applications using :mod:`rexec`, rewrite them to use something else.
+
+  (Sticking with Python 2.2 or 2.1 will not make your applications any safer
+  because there are known bugs in the :mod:`rexec` module in those versions.  To
+  repeat: if you're using :mod:`rexec`, stop using it immediately.)
+
+* The :mod:`rotor` module has been deprecated because the  algorithm it uses for
+  encryption is not believed to be secure.  If you need encryption, use one of the
+  several AES Python modules that are available separately.
+
+* The :mod:`shutil` module gained a :func:`move(src, dest)` function that
+  recursively moves a file or directory to a new location.
+
+* Support for more advanced POSIX signal handling was added to the :mod:`signal`
+  but then removed again as it proved impossible to make it work reliably across
+  platforms.
+
+* The :mod:`socket` module now supports timeouts.  You can call the
+  :meth:`settimeout(t)` method on a socket object to set a timeout of *t* seconds.
+  Subsequent socket operations that take longer than *t* seconds to complete will
+  abort and raise a :exc:`socket.timeout` exception.
+
+  The original timeout implementation was by Tim O'Malley.  Michael Gilfix
+  integrated it into the Python :mod:`socket` module and shepherded it through a
+  lengthy review.  After the code was checked in, Guido van Rossum rewrote parts
+  of it.  (This is a good example of a collaborative development process in
+  action.)
+
+* On Windows, the :mod:`socket` module now ships with Secure  Sockets Layer
+  (SSL) support.
+
+* The value of the C :const:`PYTHON_API_VERSION` macro is now exposed at the
+  Python level as ``sys.api_version``.  The current exception can be cleared by
+  calling the new :func:`sys.exc_clear` function.
+
+* The new :mod:`tarfile` module  allows reading from and writing to
+  :program:`tar`\ -format archive files. (Contributed by Lars Gustäbel.)
+
+* The new :mod:`textwrap` module contains functions for wrapping strings
+  containing paragraphs of text.  The :func:`wrap(text, width)` function takes a
+  string and returns a list containing the text split into lines of no more than
+  the chosen width.  The :func:`fill(text, width)` function returns a single
+  string, reformatted to fit into lines no longer than the chosen width. (As you
+  can guess, :func:`fill` is built on top of :func:`wrap`.  For example::
+
+     >>> import textwrap
+     >>> paragraph = "Not a whit, we defy augury: ... more text ..."
+     >>> textwrap.wrap(paragraph, 60)
+     ["Not a whit, we defy augury: there's a special providence in",
+      "the fall of a sparrow. If it be now, 'tis not to come; if it",
+      ...]
+     >>> print textwrap.fill(paragraph, 35)
+     Not a whit, we defy augury: there's
+     a special providence in the fall of
+     a sparrow. If it be now, 'tis not
+     to come; if it be not to come, it
+     will be now; if it be not now, yet
+     it will come: the readiness is all.
+     >>>
+
+  The module also contains a :class:`TextWrapper` class that actually implements
+  the text wrapping strategy.   Both the :class:`TextWrapper` class and the
+  :func:`wrap` and :func:`fill` functions support a number of additional keyword
+  arguments for fine-tuning the formatting; consult the module's documentation
+  for details. (Contributed by Greg Ward.)
+
+* The :mod:`thread` and :mod:`threading` modules now have companion modules,
+  :mod:`dummy_thread` and :mod:`dummy_threading`, that provide a do-nothing
+  implementation of the :mod:`thread` module's interface for platforms where
+  threads are not supported.  The intention is to simplify thread-aware modules
+  (ones that *don't* rely on threads to run) by putting the following code at the
+  top::
+
+     try:
+         import threading as _threading
+     except ImportError:
+         import dummy_threading as _threading
+
+  In this example, :mod:`_threading` is used as the module name to make it clear
+  that the module being used is not necessarily the actual :mod:`threading`
+  module. Code can call functions and use classes in :mod:`_threading` whether or
+  not threads are supported, avoiding an :keyword:`if` statement and making the
+  code slightly clearer.  This module will not magically make multithreaded code
+  run without threads; code that waits for another thread to return or to do
+  something will simply hang forever.
+
+* The :mod:`time` module's :func:`strptime` function has long been an annoyance
+  because it uses the platform C library's :func:`strptime` implementation, and
+  different platforms sometimes have odd bugs.  Brett Cannon contributed a
+  portable implementation that's written in pure Python and should behave
+  identically on all platforms.
+
+* The new :mod:`timeit` module helps measure how long snippets of Python code
+  take to execute.  The :file:`timeit.py` file can be run directly from the
+  command line, or the module's :class:`Timer` class can be imported and used
+  directly.  Here's a short example that figures out whether it's faster to
+  convert an 8-bit string to Unicode by appending an empty Unicode string to it or
+  by using the :func:`unicode` function::
+
+     import timeit
+
+     timer1 = timeit.Timer('unicode("abc")')
+     timer2 = timeit.Timer('"abc" + u""')
+
+     # Run three trials
+     print timer1.repeat(repeat=3, number=100000)
+     print timer2.repeat(repeat=3, number=100000)
+
+     # On my laptop this outputs:
+     # [0.36831796169281006, 0.37441694736480713, 0.35304892063140869]
+     # [0.17574405670166016, 0.18193507194519043, 0.17565798759460449]
+
+* The :mod:`Tix` module has received various bug fixes and updates for the
+  current version of the Tix package.
+
+* The :mod:`Tkinter` module now works with a thread-enabled  version of Tcl.
+  Tcl's threading model requires that widgets only be accessed from the thread in
+  which they're created; accesses from another thread can cause Tcl to panic.  For
+  certain Tcl interfaces, :mod:`Tkinter` will now automatically avoid this  when a
+  widget is accessed from a different thread by marshalling a command, passing it
+  to the correct thread, and waiting for the results.  Other interfaces can't be
+  handled automatically but :mod:`Tkinter` will now raise an exception on such an
+  access so that you can at least find out about the problem.  See
+  http://mail.python.org/pipermail/python-dev/2002-December/031107.html for a more
+  detailed explanation of this change.  (Implemented by Martin von Löwis.)
+
+  .. % 
+
+* Calling Tcl methods through :mod:`_tkinter` no longer  returns only strings.
+  Instead, if Tcl returns other objects those objects are converted to their
+  Python equivalent, if one exists, or wrapped with a :class:`_tkinter.Tcl_Obj`
+  object if no Python equivalent exists. This behavior can be controlled through
+  the :meth:`wantobjects` method of :class:`tkapp` objects.
+
+  When using :mod:`_tkinter` through the :mod:`Tkinter` module (as most Tkinter
+  applications will), this feature is always activated. It should not cause
+  compatibility problems, since Tkinter would always convert string results to
+  Python types where possible.
+
+  If any incompatibilities are found, the old behavior can be restored by setting
+  the :attr:`wantobjects` variable in the :mod:`Tkinter` module to false before
+  creating the first :class:`tkapp` object. ::
+
+     import Tkinter
+     Tkinter.wantobjects = 0
+
+  Any breakage caused by this change should be reported as a bug.
+
+* The :mod:`UserDict` module has a new :class:`DictMixin` class which defines
+  all dictionary methods for classes that already have a minimum mapping
+  interface.  This greatly simplifies writing classes that need to be
+  substitutable for dictionaries, such as the classes in  the :mod:`shelve`
+  module.
+
+  Adding the mix-in as a superclass provides the full dictionary interface
+  whenever the class defines :meth:`__getitem__`, :meth:`__setitem__`,
+  :meth:`__delitem__`, and :meth:`keys`. For example::
+
+     >>> import UserDict
+     >>> class SeqDict(UserDict.DictMixin):
+     ...     """Dictionary lookalike implemented with lists."""
+     ...     def __init__(self):
+     ...         self.keylist = []
+     ...         self.valuelist = []
+     ...     def __getitem__(self, key):
+     ...         try:
+     ...             i = self.keylist.index(key)
+     ...         except ValueError:
+     ...             raise KeyError
+     ...         return self.valuelist[i]
+     ...     def __setitem__(self, key, value):
+     ...         try:
+     ...             i = self.keylist.index(key)
+     ...             self.valuelist[i] = value
+     ...         except ValueError:
+     ...             self.keylist.append(key)
+     ...             self.valuelist.append(value)
+     ...     def __delitem__(self, key):
+     ...         try:
+     ...             i = self.keylist.index(key)
+     ...         except ValueError:
+     ...             raise KeyError
+     ...         self.keylist.pop(i)
+     ...         self.valuelist.pop(i)
+     ...     def keys(self):
+     ...         return list(self.keylist)
+     ... 
+     >>> s = SeqDict()
+     >>> dir(s)      # See that other dictionary methods are implemented
+     ['__cmp__', '__contains__', '__delitem__', '__doc__', '__getitem__',
+      '__init__', '__iter__', '__len__', '__module__', '__repr__',
+      '__setitem__', 'clear', 'get', 'has_key', 'items', 'iteritems',
+      'iterkeys', 'itervalues', 'keylist', 'keys', 'pop', 'popitem',
+      'setdefault', 'update', 'valuelist', 'values']
+
+  (Contributed by Raymond Hettinger.)
+
+* The DOM implementation in :mod:`xml.dom.minidom` can now generate XML output
+  in a particular encoding by providing an optional encoding argument to the
+  :meth:`toxml` and :meth:`toprettyxml` methods of DOM nodes.
+
+* The :mod:`xmlrpclib` module now supports an XML-RPC extension for handling nil
+  data values such as Python's ``None``.  Nil values are always supported on
+  unmarshalling an XML-RPC response.  To generate requests containing ``None``,
+  you must supply a true value for the *allow_none* parameter when creating a
+  :class:`Marshaller` instance.
+
+* The new :mod:`DocXMLRPCServer` module allows writing self-documenting XML-RPC
+  servers. Run it in demo mode (as a program) to see it in action.   Pointing the
+  Web browser to the RPC server produces pydoc-style documentation; pointing
+  xmlrpclib to the server allows invoking the actual methods. (Contributed by
+  Brian Quinlan.)
+
+* Support for internationalized domain names (RFCs 3454, 3490, 3491, and 3492)
+  has been added. The "idna" encoding can be used to convert between a Unicode
+  domain name and the ASCII-compatible encoding (ACE) of that name. ::
+
+     >{}>{}> u"www.Alliancefrançaise.nu".encode("idna")
+     'www.xn--alliancefranaise-npb.nu'
+
+  The :mod:`socket` module has also been extended to transparently convert
+  Unicode hostnames to the ACE version before passing them to the C library.
+  Modules that deal with hostnames such as :mod:`httplib` and :mod:`ftplib`)
+  also support Unicode host names; :mod:`httplib` also sends HTTP ``Host``
+  headers using the ACE version of the domain name.  :mod:`urllib` supports
+  Unicode URLs with non-ASCII host names as long as the ``path`` part of the URL
+  is ASCII only.
+
+  To implement this change, the :mod:`stringprep` module, the  ``mkstringprep``
+  tool and the ``punycode`` encoding have been added.
+
+.. % ======================================================================
+
+
+Date/Time Type
+--------------
+
+Date and time types suitable for expressing timestamps were added as the
+:mod:`datetime` module.  The types don't support different calendars or many
+fancy features, and just stick to the basics of representing time.
+
+The three primary types are: :class:`date`, representing a day, month, and year;
+:class:`time`, consisting of hour, minute, and second; and :class:`datetime`,
+which contains all the attributes of both :class:`date` and :class:`time`.
+There's also a :class:`timedelta` class representing differences between two
+points in time, and time zone logic is implemented by classes inheriting from
+the abstract :class:`tzinfo` class.
+
+You can create instances of :class:`date` and :class:`time` by either supplying
+keyword arguments to the appropriate constructor, e.g.
+``datetime.date(year=1972, month=10, day=15)``, or by using one of a number of
+class methods.  For example, the :meth:`date.today` class method returns the
+current local date.
+
+Once created, instances of the date/time classes are all immutable. There are a
+number of methods for producing formatted strings from objects::
+
+   >>> import datetime
+   >>> now = datetime.datetime.now()
+   >>> now.isoformat()
+   '2002-12-30T21:27:03.994956'
+   >>> now.ctime()  # Only available on date, datetime
+   'Mon Dec 30 21:27:03 2002'
+   >>> now.strftime('%Y %d %b')
+   '2002 30 Dec'
+
+The :meth:`replace` method allows modifying one or more fields  of a
+:class:`date` or :class:`datetime` instance, returning a new instance::
+
+   >>> d = datetime.datetime.now()
+   >>> d
+   datetime.datetime(2002, 12, 30, 22, 15, 38, 827738)
+   >>> d.replace(year=2001, hour = 12)
+   datetime.datetime(2001, 12, 30, 12, 15, 38, 827738)
+   >>>
+
+Instances can be compared, hashed, and converted to strings (the result is the
+same as that of :meth:`isoformat`).  :class:`date` and :class:`datetime`
+instances can be subtracted from each other, and added to :class:`timedelta`
+instances.  The largest missing feature is that there's no standard library
+support for parsing strings and getting back a :class:`date` or
+:class:`datetime`.
+
+For more information, refer to the module's reference documentation.
+(Contributed by Tim Peters.)
+
+.. % ======================================================================
+
+
+The optparse Module
+-------------------
+
+The :mod:`getopt` module provides simple parsing of command-line arguments.  The
+new :mod:`optparse` module (originally named Optik) provides more elaborate
+command-line parsing that follows the Unix conventions, automatically creates
+the output for :option:`--help`, and can perform different actions for different
+options.
+
+You start by creating an instance of :class:`OptionParser` and telling it what
+your program's options are. ::
+
+   import sys
+   from optparse import OptionParser
+
+   op = OptionParser()
+   op.add_option('-i', '--input',
+                 action='store', type='string', dest='input',
+                 help='set input filename')
+   op.add_option('-l', '--length',
+                 action='store', type='int', dest='length',
+                 help='set maximum length of output')
+
+Parsing a command line is then done by calling the :meth:`parse_args` method. ::
+
+   options, args = op.parse_args(sys.argv[1:])
+   print options
+   print args
+
+This returns an object containing all of the option values, and a list of
+strings containing the remaining arguments.
+
+Invoking the script with the various arguments now works as you'd expect it to.
+Note that the length argument is automatically converted to an integer. ::
+
+   $ ./python opt.py -i data arg1
+   <Values at 0x400cad4c: {'input': 'data', 'length': None}>
+   ['arg1']
+   $ ./python opt.py --input=data --length=4
+   <Values at 0x400cad2c: {'input': 'data', 'length': 4}>
+   []
+   $
+
+The help message is automatically generated for you::
+
+   $ ./python opt.py --help
+   usage: opt.py [options]
+
+   options:
+     -h, --help            show this help message and exit
+     -iINPUT, --input=INPUT
+                           set input filename
+     -lLENGTH, --length=LENGTH
+                           set maximum length of output
+   $ 
+
+See the module's documentation for more details.
+
+
+Optik was written by Greg Ward, with suggestions from the readers of the Getopt
+SIG.
+
+.. % ======================================================================
+
+
+.. _section-pymalloc:
+
+Pymalloc: A Specialized Object Allocator
+========================================
+
+Pymalloc, a specialized object allocator written by Vladimir Marangozov, was a
+feature added to Python 2.1.  Pymalloc is intended to be faster than the system
+:cfunc:`malloc` and to have less memory overhead for allocation patterns typical
+of Python programs. The allocator uses C's :cfunc:`malloc` function to get large
+pools of memory and then fulfills smaller memory requests from these pools.
+
+In 2.1 and 2.2, pymalloc was an experimental feature and wasn't enabled by
+default; you had to explicitly enable it when compiling Python by providing the
+:option:`--with-pymalloc` option to the :program:`configure` script.  In 2.3,
+pymalloc has had further enhancements and is now enabled by default; you'll have
+to supply :option:`--without-pymalloc` to disable it.
+
+This change is transparent to code written in Python; however, pymalloc may
+expose bugs in C extensions.  Authors of C extension modules should test their
+code with pymalloc enabled, because some incorrect code may cause core dumps at
+runtime.
+
+There's one particularly common error that causes problems.  There are a number
+of memory allocation functions in Python's C API that have previously just been
+aliases for the C library's :cfunc:`malloc` and :cfunc:`free`, meaning that if
+you accidentally called mismatched functions the error wouldn't be noticeable.
+When the object allocator is enabled, these functions aren't aliases of
+:cfunc:`malloc` and :cfunc:`free` any more, and calling the wrong function to
+free memory may get you a core dump.  For example, if memory was allocated using
+:cfunc:`PyObject_Malloc`, it has to be freed using :cfunc:`PyObject_Free`, not
+:cfunc:`free`.  A few modules included with Python fell afoul of this and had to
+be fixed; doubtless there are more third-party modules that will have the same
+problem.
+
+As part of this change, the confusing multiple interfaces for allocating memory
+have been consolidated down into two API families. Memory allocated with one
+family must not be manipulated with functions from the other family.  There is
+one family for allocating chunks of memory and another family of functions
+specifically for allocating Python objects.
+
+* To allocate and free an undistinguished chunk of memory use the "raw memory"
+  family: :cfunc:`PyMem_Malloc`, :cfunc:`PyMem_Realloc`, and :cfunc:`PyMem_Free`.
+
+* The "object memory" family is the interface to the pymalloc facility described
+  above and is biased towards a large number of "small" allocations:
+  :cfunc:`PyObject_Malloc`, :cfunc:`PyObject_Realloc`, and :cfunc:`PyObject_Free`.
+
+* To allocate and free Python objects, use the "object" family
+  :cfunc:`PyObject_New`, :cfunc:`PyObject_NewVar`, and :cfunc:`PyObject_Del`.
+
+Thanks to lots of work by Tim Peters, pymalloc in 2.3 also provides debugging
+features to catch memory overwrites and doubled frees in both extension modules
+and in the interpreter itself.  To enable this support, compile a debugging
+version of the Python interpreter by running :program:`configure` with
+:option:`--with-pydebug`.
+
+To aid extension writers, a header file :file:`Misc/pymemcompat.h` is
+distributed with the source to Python 2.3 that allows Python extensions to use
+the 2.3 interfaces to memory allocation while compiling against any version of
+Python since 1.5.2.  You would copy the file from Python's source distribution
+and bundle it with the source of your extension.
+
+
+.. seealso::
+
+   http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/python/python/dist/src/Objects/obmalloc.c
+      For the full details of the pymalloc implementation, see the comments at the top
+      of the file :file:`Objects/obmalloc.c` in the Python source code.  The above
+      link points to the file within the SourceForge CVS browser.
+
+.. % ======================================================================
+
+
+Build and C API Changes
+=======================
+
+Changes to Python's build process and to the C API include:
+
+* The cycle detection implementation used by the garbage collection has proven
+  to be stable, so it's now been made mandatory.  You can no longer compile Python
+  without it, and the :option:`--with-cycle-gc` switch to :program:`configure` has
+  been removed.
+
+* Python can now optionally be built as a shared library
+  (:file:`libpython2.3.so`) by supplying :option:`--enable-shared` when running
+  Python's :program:`configure` script.  (Contributed by Ondrej Palkovsky.)
+
+* The :cmacro:`DL_EXPORT` and :cmacro:`DL_IMPORT` macros are now deprecated.
+  Initialization functions for Python extension modules should now be declared
+  using the new macro :cmacro:`PyMODINIT_FUNC`, while the Python core will
+  generally use the :cmacro:`PyAPI_FUNC` and :cmacro:`PyAPI_DATA` macros.
+
+* The interpreter can be compiled without any docstrings for the built-in
+  functions and modules by supplying :option:`--without-doc-strings` to the
+  :program:`configure` script. This makes the Python executable about 10% smaller,
+  but will also mean that you can't get help for Python's built-ins.  (Contributed
+  by Gustavo Niemeyer.)
+
+* The :cfunc:`PyArg_NoArgs` macro is now deprecated, and code that uses it
+  should be changed.  For Python 2.2 and later, the method definition table can
+  specify the :const:`METH_NOARGS` flag, signalling that there are no arguments,
+  and the argument checking can then be removed.  If compatibility with pre-2.2
+  versions of Python is important, the code could use ``PyArg_ParseTuple(args,
+  "")`` instead, but this will be slower than using :const:`METH_NOARGS`.
+
+* :cfunc:`PyArg_ParseTuple` accepts new format characters for various sizes of
+  unsigned integers: ``B`` for :ctype:`unsigned char`, ``H`` for :ctype:`unsigned
+  short int`,  ``I`` for :ctype:`unsigned int`,  and ``K`` for :ctype:`unsigned
+  long long`.
+
+* A new function, :cfunc:`PyObject_DelItemString(mapping, char \*key)` was added
+  as shorthand for ``PyObject_DelItem(mapping, PyString_New(key))``.
+
+* File objects now manage their internal string buffer differently, increasing
+  it exponentially when needed.  This results in the benchmark tests in
+  :file:`Lib/test/test_bufio.py` speeding up considerably (from 57 seconds to 1.7
+  seconds, according to one measurement).
+
+* It's now possible to define class and static methods for a C extension type by
+  setting either the :const:`METH_CLASS` or :const:`METH_STATIC` flags in a
+  method's :ctype:`PyMethodDef` structure.
+
+* Python now includes a copy of the Expat XML parser's source code, removing any
+  dependence on a system version or local installation of Expat.
+
+* If you dynamically allocate type objects in your extension, you should be
+  aware of a change in the rules relating to the :attr:`__module__` and
+  :attr:`__name__` attributes.  In summary, you will want to ensure the type's
+  dictionary contains a ``'__module__'`` key; making the module name the part of
+  the type name leading up to the final period will no longer have the desired
+  effect.  For more detail, read the API reference documentation or the  source.
+
+.. % ======================================================================
+
+
+Port-Specific Changes
+---------------------
+
+Support for a port to IBM's OS/2 using the EMX runtime environment was merged
+into the main Python source tree.  EMX is a POSIX emulation layer over the OS/2
+system APIs.  The Python port for EMX tries to support all the POSIX-like
+capability exposed by the EMX runtime, and mostly succeeds; :func:`fork` and
+:func:`fcntl` are restricted by the limitations of the underlying emulation
+layer.  The standard OS/2 port, which uses IBM's Visual Age compiler, also
+gained support for case-sensitive import semantics as part of the integration of
+the EMX port into CVS.  (Contributed by Andrew MacIntyre.)
+
+On MacOS, most toolbox modules have been weaklinked to improve backward
+compatibility.  This means that modules will no longer fail to load if a single
+routine is missing on the current OS version. Instead calling the missing
+routine will raise an exception. (Contributed by Jack Jansen.)
+
+The RPM spec files, found in the :file:`Misc/RPM/` directory in the Python
+source distribution, were updated for 2.3.  (Contributed by Sean Reifschneider.)
+
+Other new platforms now supported by Python include AtheOS
+(http://www.atheos.cx/), GNU/Hurd, and OpenVMS.
+
+.. % ======================================================================
+
+
+.. _section-other:
+
+Other Changes and Fixes
+=======================
+
+As usual, there were a bunch of other improvements and bugfixes scattered
+throughout the source tree.  A search through the CVS change logs finds there
+were 523 patches applied and 514 bugs fixed between Python 2.2 and 2.3.  Both
+figures are likely to be underestimates.
+
+Some of the more notable changes are:
+
+* If the :envvar:`PYTHONINSPECT` environment variable is set, the Python
+  interpreter will enter the interactive prompt after running a Python program, as
+  if Python had been invoked with the :option:`-i` option. The environment
+  variable can be set before running the Python interpreter, or it can be set by
+  the Python program as part of its execution.
+
+* The :file:`regrtest.py` script now provides a way to allow "all resources
+  except *foo*."  A resource name passed to the :option:`-u` option can now be
+  prefixed with a hyphen (``'-'``) to mean "remove this resource."  For example,
+  the option '``-uall,-bsddb``' could be used to enable the use of all resources
+  except ``bsddb``.
+
+* The tools used to build the documentation now work under Cygwin as well as
+  Unix.
+
+* The ``SET_LINENO`` opcode has been removed.  Back in the mists of time, this
+  opcode was needed to produce line numbers in tracebacks and support trace
+  functions (for, e.g., :mod:`pdb`). Since Python 1.5, the line numbers in
+  tracebacks have been computed using a different mechanism that works with
+  "python -O".  For Python 2.3 Michael Hudson implemented a similar scheme to
+  determine when to call the trace function, removing the need for ``SET_LINENO``
+  entirely.
+
+  It would be difficult to detect any resulting difference from Python code, apart
+  from a slight speed up when Python is run without :option:`-O`.
+
+  C extensions that access the :attr:`f_lineno` field of frame objects should
+  instead call ``PyCode_Addr2Line(f->f_code, f->f_lasti)``. This will have the
+  added effect of making the code work as desired under "python -O" in earlier
+  versions of Python.
+
+  A nifty new feature is that trace functions can now assign to the
+  :attr:`f_lineno` attribute of frame objects, changing the line that will be
+  executed next.  A ``jump`` command has been added to the :mod:`pdb` debugger
+  taking advantage of this new feature. (Implemented by Richie Hindle.)
+
+.. % ======================================================================
+
+
+Porting to Python 2.3
+=====================
+
+This section lists previously described changes that may require changes to your
+code:
+
+* :keyword:`yield` is now always a keyword; if it's used as a variable name in
+  your code, a different name must be chosen.
+
+* For strings *X* and *Y*, ``X in Y`` now works if *X* is more than one
+  character long.
+
+* The :func:`int` type constructor will now return a long integer instead of
+  raising an :exc:`OverflowError` when a string or floating-point number is too
+  large to fit into an integer.
+
+* If you have Unicode strings that contain 8-bit characters, you must declare
+  the file's encoding (UTF-8, Latin-1, or whatever) by adding a comment to the top
+  of the file.  See section :ref:`section-encodings` for more information.
+
+* Calling Tcl methods through :mod:`_tkinter` no longer  returns only strings.
+  Instead, if Tcl returns other objects those objects are converted to their
+  Python equivalent, if one exists, or wrapped with a :class:`_tkinter.Tcl_Obj`
+  object if no Python equivalent exists.
+
+* Large octal and hex literals such as ``0xffffffff`` now trigger a
+  :exc:`FutureWarning`. Currently they're stored as 32-bit numbers and result in a
+  negative value, but in Python 2.4 they'll become positive long integers.
+
+  There are a few ways to fix this warning.  If you really need a positive number,
+  just add an ``L`` to the end of the literal.  If you're trying to get a 32-bit
+  integer with low bits set and have previously used an expression such as ``~(1
+  << 31)``, it's probably clearest to start with all bits set and clear the
+  desired upper bits. For example, to clear just the top bit (bit 31), you could
+  write ``0xffffffffL &~(1L<<31)``.
+
+  .. % The empty groups below prevent conversion to guillemets.
+
+* You can no longer disable assertions by assigning to ``__debug__``.
+
+* The Distutils :func:`setup` function has gained various new keyword arguments
+  such as *depends*.  Old versions of the Distutils will abort if passed unknown
+  keywords.  A solution is to check for the presence of the new
+  :func:`get_distutil_options` function in your :file:`setup.py` and only uses the
+  new keywords with a version of the Distutils that supports them::
+
+     from distutils import core
+
+     kw = {'sources': 'foo.c', ...}
+     if hasattr(core, 'get_distutil_options'):
+         kw['depends'] = ['foo.h']
+     ext = Extension(**kw)
+
+* Using ``None`` as a variable name will now result in a :exc:`SyntaxWarning`
+  warning.
+
+* Names of extension types defined by the modules included with Python now
+  contain the module and a ``'.'`` in front of the type name.
+
+.. % ======================================================================
+
+
+.. _acks:
+
+Acknowledgements
+================
+
+The author would like to thank the following people for offering suggestions,
+corrections and assistance with various drafts of this article: Jeff Bauer,
+Simon Brunning, Brett Cannon, Michael Chermside, Andrew Dalke, Scott David
+Daniels, Fred L. Drake, Jr., David Fraser,  Kelly Gerber, Raymond Hettinger,
+Michael Hudson, Chris Lambert, Detlef Lannert, Martin von Löwis, Andrew
+MacIntyre, Lalo Martins, Chad Netzer, Gustavo Niemeyer, Neal Norwitz, Hans
+Nowak, Chris Reedy, Francesco Ricciardi, Vinay Sajip, Neil Schemenauer, Roman
+Suzi, Jason Tishler, Just van Rossum.
+
diff --git a/Doc/whatsnew/2.4.rst b/Doc/whatsnew/2.4.rst
new file mode 100644
index 0000000..d782f5d
--- /dev/null
+++ b/Doc/whatsnew/2.4.rst
@@ -0,0 +1,1571 @@
+****************************
+  What's New in Python 2.4  
+****************************
+
+:Author: A.M. Kuchling
+
+.. |release| replace:: 1.02
+
+.. % $Id: whatsnew24.tex 55005 2007-04-27 19:54:29Z guido.van.rossum $
+.. % Don't write extensive text for new sections; I'll do that.
+.. % Feel free to add commented-out reminders of things that need
+.. % to be covered.  --amk
+
+This article explains the new features in Python 2.4.1, released on March 30,
+2005.
+
+Python 2.4 is a medium-sized release.  It doesn't introduce as many changes as
+the radical Python 2.2, but introduces more features than the conservative 2.3
+release.  The most significant new language features are function decorators and
+generator expressions; most other changes are to the standard library.
+
+According to the CVS change logs, there were 481 patches applied and 502 bugs
+fixed between Python 2.3 and 2.4.  Both figures are likely to be underestimates.
+
+This article doesn't attempt to provide a complete specification of every single
+new feature, but instead provides a brief introduction to each feature.  For
+full details, you should refer to the documentation for Python 2.4, such as the
+Python Library Reference and the Python Reference Manual.  Often you will be
+referred to the PEP for a particular new feature for explanations of the
+implementation and design rationale.
+
+.. % ======================================================================
+
+
+PEP 218: Built-In Set Objects
+=============================
+
+Python 2.3 introduced the :mod:`sets` module.  C implementations of set data
+types have now been added to the Python core as two new built-in types,
+:func:`set(iterable)` and :func:`frozenset(iterable)`.  They provide high speed
+operations for membership testing, for eliminating duplicates from sequences,
+and for mathematical operations like unions, intersections, differences, and
+symmetric differences. ::
+
+   >>> a = set('abracadabra')              # form a set from a string
+   >>> 'z' in a                            # fast membership testing
+   False
+   >>> a                                   # unique letters in a
+   set(['a', 'r', 'b', 'c', 'd'])
+   >>> ''.join(a)                          # convert back into a string
+   'arbcd'
+
+   >>> b = set('alacazam')                 # form a second set
+   >>> a - b                               # letters in a but not in b
+   set(['r', 'd', 'b'])
+   >>> a | b                               # letters in either a or b
+   set(['a', 'c', 'r', 'd', 'b', 'm', 'z', 'l'])
+   >>> a & b                               # letters in both a and b
+   set(['a', 'c'])
+   >>> a ^ b                               # letters in a or b but not both
+   set(['r', 'd', 'b', 'm', 'z', 'l'])
+
+   >>> a.add('z')                          # add a new element
+   >>> a.update('wxy')                     # add multiple new elements
+   >>> a
+   set(['a', 'c', 'b', 'd', 'r', 'w', 'y', 'x', 'z'])       
+   >>> a.remove('x')                       # take one element out
+   >>> a
+   set(['a', 'c', 'b', 'd', 'r', 'w', 'y', 'z'])       
+
+The :func:`frozenset` type is an immutable version of :func:`set`. Since it is
+immutable and hashable, it may be used as a dictionary key or as a member of
+another set.
+
+The :mod:`sets` module remains in the standard library, and may be useful if you
+wish to subclass the :class:`Set` or :class:`ImmutableSet` classes.  There are
+currently no plans to deprecate the module.
+
+
+.. seealso::
+
+   :pep:`218` - Adding a Built-In Set Object Type
+      Originally proposed by Greg Wilson and ultimately implemented by Raymond
+      Hettinger.
+
+.. % ======================================================================
+
+
+PEP 237: Unifying Long Integers and Integers
+============================================
+
+The lengthy transition process for this PEP, begun in Python 2.2, takes another
+step forward in Python 2.4.  In 2.3, certain integer operations that would
+behave differently after int/long unification triggered :exc:`FutureWarning`
+warnings and returned values limited to 32 or 64 bits (depending on your
+platform).  In 2.4, these expressions no longer produce a warning and instead
+produce a different result that's usually a long integer.
+
+The problematic expressions are primarily left shifts and lengthy hexadecimal
+and octal constants.  For example, ``2 << 32`` results in a warning in 2.3,
+evaluating to 0 on 32-bit platforms.  In Python 2.4, this expression now returns
+the correct answer, 8589934592.
+
+
+.. seealso::
+
+   :pep:`237` - Unifying Long Integers and Integers
+      Original PEP written by Moshe Zadka and GvR.  The changes for 2.4 were
+      implemented by  Kalle Svensson.
+
+.. % ======================================================================
+
+
+PEP 289: Generator Expressions
+==============================
+
+The iterator feature introduced in Python 2.2 and the :mod:`itertools` module
+make it easier to write programs that loop through large data sets without
+having the entire data set in memory at one time.  List comprehensions don't fit
+into this picture very well because they produce a Python list object containing
+all of the items.  This unavoidably pulls all of the objects into memory, which
+can be a problem if your data set is very large.  When trying to write a
+functionally-styled program, it would be natural to write something like::
+
+   links = [link for link in get_all_links() if not link.followed]
+   for link in links:
+       ...
+
+instead of  ::
+
+   for link in get_all_links():
+       if link.followed:
+           continue
+       ...
+
+The first form is more concise and perhaps more readable, but if you're dealing
+with a large number of link objects you'd have to write the second form to avoid
+having all link objects in memory at the same time.
+
+Generator expressions work similarly to list comprehensions but don't
+materialize the entire list; instead they create a generator that will return
+elements one by one.  The above example could be written as::
+
+   links = (link for link in get_all_links() if not link.followed)
+   for link in links:
+       ...
+
+Generator expressions always have to be written inside parentheses, as in the
+above example.  The parentheses signalling a function call also count, so if you
+want to create an iterator that will be immediately passed to a function you
+could write::
+
+   print sum(obj.count for obj in list_all_objects())
+
+Generator expressions differ from list comprehensions in various small ways.
+Most notably, the loop variable (*obj* in the above example) is not accessible
+outside of the generator expression.  List comprehensions leave the variable
+assigned to its last value; future versions of Python will change this, making
+list comprehensions match generator expressions in this respect.
+
+
+.. seealso::
+
+   :pep:`289` - Generator Expressions
+      Proposed by Raymond Hettinger and implemented by Jiwon Seo with early efforts
+      steered by Hye-Shik Chang.
+
+.. % ======================================================================
+
+
+PEP 292: Simpler String Substitutions
+=====================================
+
+Some new classes in the standard library provide an alternative mechanism for
+substituting variables into strings; this style of substitution may be better
+for applications where untrained users need to edit templates.
+
+The usual way of substituting variables by name is the ``%`` operator::
+
+   >>> '%(page)i: %(title)s' % {'page':2, 'title': 'The Best of Times'}
+   '2: The Best of Times'
+
+When writing the template string, it can be easy to forget the ``i`` or ``s``
+after the closing parenthesis.  This isn't a big problem if the template is in a
+Python module, because you run the code, get an "Unsupported format character"
+:exc:`ValueError`, and fix the problem.  However, consider an application such
+as Mailman where template strings or translations are being edited by users who
+aren't aware of the Python language.  The format string's syntax is complicated
+to explain to such users, and if they make a mistake, it's difficult to provide
+helpful feedback to them.
+
+PEP 292 adds a :class:`Template` class to the :mod:`string` module that uses
+``$`` to indicate a substitution::
+
+   >>> import string
+   >>> t = string.Template('$page: $title')
+   >>> t.substitute({'page':2, 'title': 'The Best of Times'})
+   '2: The Best of Times'
+
+If a key is missing from the dictionary, the :meth:`substitute` method will
+raise a :exc:`KeyError`.  There's also a :meth:`safe_substitute` method that
+ignores missing keys:
+
+.. % $ Terminate $-mode for Emacs
+
+::
+
+   >>> t = string.Template('$page: $title')
+   >>> t.safe_substitute({'page':3})
+   '3: $title'
+
+.. % $ Terminate math-mode for Emacs
+
+
+.. seealso::
+
+   :pep:`292` - Simpler String Substitutions
+      Written and implemented  by Barry Warsaw.
+
+.. % ======================================================================
+
+
+PEP 318: Decorators for Functions and Methods
+=============================================
+
+Python 2.2 extended Python's object model by adding static methods and class
+methods, but it didn't extend Python's syntax to provide any new way of defining
+static or class methods.  Instead, you had to write a :keyword:`def` statement
+in the usual way, and pass the resulting method to a :func:`staticmethod` or
+:func:`classmethod` function that would wrap up the function as a method of the
+new type. Your code would look like this::
+
+   class C:
+      def meth (cls):
+          ...
+
+      meth = classmethod(meth)   # Rebind name to wrapped-up class method
+
+If the method was very long, it would be easy to miss or forget the
+:func:`classmethod` invocation after the function body.
+
+The intention was always to add some syntax to make such definitions more
+readable, but at the time of 2.2's release a good syntax was not obvious.  Today
+a good syntax *still* isn't obvious but users are asking for easier access to
+the feature; a new syntactic feature has been added to meet this need.
+
+The new feature is called "function decorators".  The name comes from the idea
+that :func:`classmethod`, :func:`staticmethod`, and friends are storing
+additional information on a function object; they're *decorating* functions with
+more details.
+
+The notation borrows from Java and uses the ``'@'`` character as an indicator.
+Using the new syntax, the example above would be written::
+
+   class C:
+
+      @classmethod
+      def meth (cls):
+          ...
+
+
+The ``@classmethod`` is shorthand for the ``meth=classmethod(meth)`` assignment.
+More generally, if you have the following::
+
+   @A
+   @B
+   @C
+   def f ():
+       ...
+
+It's equivalent to the following pre-decorator code::
+
+   def f(): ...
+   f = A(B(C(f)))
+
+Decorators must come on the line before a function definition, one decorator per
+line, and can't be on the same line as the def statement, meaning that ``@A def
+f(): ...`` is illegal.  You can only decorate function definitions, either at
+the module level or inside a class; you can't decorate class definitions.
+
+A decorator is just a function that takes the function to be decorated as an
+argument and returns either the same function or some new object.  The return
+value of the decorator need not be callable (though it typically is), unless
+further decorators will be applied to the result.  It's easy to write your own
+decorators.  The following simple example just sets an attribute on the function
+object::
+
+   >>> def deco(func):
+   ...    func.attr = 'decorated'
+   ...    return func
+   ...
+   >>> @deco
+   ... def f(): pass
+   ...
+   >>> f
+   <function f at 0x402ef0d4>
+   >>> f.attr
+   'decorated'
+   >>>
+
+As a slightly more realistic example, the following decorator checks that the
+supplied argument is an integer::
+
+   def require_int (func):
+       def wrapper (arg):
+           assert isinstance(arg, int)
+           return func(arg)
+
+       return wrapper
+
+   @require_int
+   def p1 (arg):
+       print arg
+
+   @require_int
+   def p2(arg):
+       print arg*2
+
+An example in :pep:`318` contains a fancier version of this idea that lets you
+both specify the required type and check the returned type.
+
+Decorator functions can take arguments.  If arguments are supplied, your
+decorator function is called with only those arguments and must return a new
+decorator function; this function must take a single function and return a
+function, as previously described.  In other words, ``@A @B @C(args)`` becomes::
+
+   def f(): ...
+   _deco = C(args)
+   f = A(B(_deco(f)))
+
+Getting this right can be slightly brain-bending, but it's not too difficult.
+
+A small related change makes the :attr:`func_name` attribute of functions
+writable.  This attribute is used to display function names in tracebacks, so
+decorators should change the name of any new function that's constructed and
+returned.
+
+
+.. seealso::
+
+   :pep:`318` - Decorators for Functions, Methods and Classes
+      Written  by Kevin D. Smith, Jim Jewett, and Skip Montanaro.  Several people
+      wrote patches implementing function decorators, but the one that was actually
+      checked in was patch #979728, written by Mark Russell.
+
+   http://www.python.org/moin/PythonDecoratorLibrary
+      This Wiki page contains several examples of decorators.
+
+.. % ======================================================================
+
+
+PEP 322: Reverse Iteration
+==========================
+
+A new built-in function, :func:`reversed(seq)`, takes a sequence and returns an
+iterator that loops over the elements of the sequence  in reverse order.   ::
+
+   >>> for i in reversed(xrange(1,4)):
+   ...    print i
+   ... 
+   3
+   2
+   1
+
+Compared to extended slicing, such as ``range(1,4)[::-1]``, :func:`reversed` is
+easier to read, runs faster, and uses substantially less memory.
+
+Note that :func:`reversed` only accepts sequences, not arbitrary iterators.  If
+you want to reverse an iterator, first convert it to  a list with :func:`list`.
+::
+
+   >>> input = open('/etc/passwd', 'r')
+   >>> for line in reversed(list(input)):
+   ...   print line
+   ... 
+   root:*:0:0:System Administrator:/var/root:/bin/tcsh
+     ...
+
+
+.. seealso::
+
+   :pep:`322` - Reverse Iteration
+      Written and implemented by Raymond Hettinger.
+
+.. % ======================================================================
+
+
+PEP 324: New subprocess Module
+==============================
+
+The standard library provides a number of ways to execute a subprocess, offering
+different features and different levels of complexity.
+:func:`os.system(command)` is easy to use, but slow (it runs a shell process
+which executes the command) and dangerous (you have to be careful about escaping
+the shell's metacharacters).  The :mod:`popen2` module offers classes that can
+capture standard output and standard error from the subprocess, but the naming
+is confusing.  The :mod:`subprocess` module cleans  this up, providing a unified
+interface that offers all the features you might need.
+
+Instead of :mod:`popen2`'s collection of classes, :mod:`subprocess` contains a
+single class called :class:`Popen`  whose constructor supports a number of
+different keyword arguments. ::
+
+   class Popen(args, bufsize=0, executable=None,
+   	    stdin=None, stdout=None, stderr=None,
+   	    preexec_fn=None, close_fds=False, shell=False,
+   	    cwd=None, env=None, universal_newlines=False,
+   	    startupinfo=None, creationflags=0):
+
+*args* is commonly a sequence of strings that will be the arguments to the
+program executed as the subprocess.  (If the *shell* argument is true, *args*
+can be a string which will then be passed on to the shell for interpretation,
+just as :func:`os.system` does.)
+
+*stdin*, *stdout*, and *stderr* specify what the subprocess's input, output, and
+error streams will be.  You can provide a file object or a file descriptor, or
+you can use the constant ``subprocess.PIPE`` to create a pipe between the
+subprocess and the parent.
+
+The constructor has a number of handy options:
+
+* *close_fds* requests that all file descriptors be closed before running the
+  subprocess.
+
+* *cwd* specifies the working directory in which the subprocess will be executed
+  (defaulting to whatever the parent's working directory is).
+
+* *env* is a dictionary specifying environment variables.
+
+* *preexec_fn* is a function that gets called before the child is started.
+
+* *universal_newlines* opens the child's input and output using Python's
+  universal newline feature.
+
+Once you've created the :class:`Popen` instance,  you can call its :meth:`wait`
+method to pause until the subprocess has exited, :meth:`poll` to check if it's
+exited without pausing,  or :meth:`communicate(data)` to send the string *data*
+to the subprocess's standard input.   :meth:`communicate(data)`  then reads any
+data that the subprocess has sent to its standard output  or standard error,
+returning a tuple ``(stdout_data, stderr_data)``.
+
+:func:`call` is a shortcut that passes its arguments along to the :class:`Popen`
+constructor, waits for the command to complete, and returns the status code of
+the subprocess.  It can serve as a safer analog to :func:`os.system`::
+
+   sts = subprocess.call(['dpkg', '-i', '/tmp/new-package.deb'])
+   if sts == 0:
+       # Success
+       ...
+   else:
+       # dpkg returned an error
+       ...
+
+The command is invoked without use of the shell.  If you really do want to  use
+the shell, you can add ``shell=True`` as a keyword argument and provide a string
+instead of a sequence::
+
+   sts = subprocess.call('dpkg -i /tmp/new-package.deb', shell=True)
+
+The PEP takes various examples of shell and Python code and shows how they'd be
+translated into Python code that uses :mod:`subprocess`.  Reading this section
+of the PEP is highly recommended.
+
+
+.. seealso::
+
+   :pep:`324` - subprocess - New process module
+      Written and implemented by Peter Åstrand, with assistance from Fredrik Lundh and
+      others.
+
+.. % ======================================================================
+
+
+PEP 327: Decimal Data Type
+==========================
+
+Python has always supported floating-point (FP) numbers, based on the underlying
+C :ctype:`double` type, as a data type.  However, while most programming
+languages provide a floating-point type, many people (even programmers) are
+unaware that floating-point numbers don't represent certain decimal fractions
+accurately.  The new :class:`Decimal` type can represent these fractions
+accurately, up to a user-specified precision limit.
+
+
+Why is Decimal needed?
+----------------------
+
+The limitations arise from the representation used for floating-point numbers.
+FP numbers are made up of three components:
+
+* The sign, which is positive or negative.
+
+* The mantissa, which is a single-digit binary number   followed by a fractional
+  part.  For example, ``1.01`` in base-2 notation is ``1 + 0/2 + 1/4``, or 1.25 in
+  decimal notation.
+
+* The exponent, which tells where the decimal point is located in the number
+  represented.
+
+For example, the number 1.25 has positive sign, a mantissa value of 1.01 (in
+binary), and an exponent of 0 (the decimal point doesn't need to be shifted).
+The number 5 has the same sign and mantissa, but the exponent is 2 because the
+mantissa is multiplied by 4 (2 to the power of the exponent 2); 1.25 \* 4 equals
+5.
+
+Modern systems usually provide floating-point support that conforms to a
+standard called IEEE 754.  C's :ctype:`double` type is usually implemented as a
+64-bit IEEE 754 number, which uses 52 bits of space for the mantissa.  This
+means that numbers can only be specified to 52 bits of precision.  If you're
+trying to represent numbers whose expansion repeats endlessly, the expansion is
+cut off after 52 bits. Unfortunately, most software needs to produce output in
+base 10, and common fractions in base 10 are often repeating decimals in binary.
+For example, 1.1 decimal is binary ``1.0001100110011 ...``; .1 = 1/16 + 1/32 +
+1/256 plus an infinite number of additional terms.  IEEE 754 has to chop off
+that infinitely repeated decimal after 52 digits, so the representation is
+slightly inaccurate.
+
+Sometimes you can see this inaccuracy when the number is printed::
+
+   >>> 1.1
+   1.1000000000000001
+
+The inaccuracy isn't always visible when you print the number because the FP-to-
+decimal-string conversion is provided by the C library, and most C libraries try
+to produce sensible output.  Even if it's not displayed, however, the inaccuracy
+is still there and subsequent operations can magnify the error.
+
+For many applications this doesn't matter.  If I'm plotting points and
+displaying them on my monitor, the difference between 1.1 and 1.1000000000000001
+is too small to be visible.  Reports often limit output to a certain number of
+decimal places, and if you round the number to two or three or even eight
+decimal places, the error is never apparent.  However, for applications where it
+does matter,  it's a lot of work to implement your own custom arithmetic
+routines.
+
+Hence, the :class:`Decimal` type was created.
+
+
+The :class:`Decimal` type
+-------------------------
+
+A new module, :mod:`decimal`, was added to Python's standard library.  It
+contains two classes, :class:`Decimal` and :class:`Context`.  :class:`Decimal`
+instances represent numbers, and :class:`Context` instances are used to wrap up
+various settings such as the precision and default rounding mode.
+
+:class:`Decimal` instances are immutable, like regular Python integers and FP
+numbers; once it's been created, you can't change the value an instance
+represents.  :class:`Decimal` instances can be created from integers or
+strings::
+
+   >>> import decimal
+   >>> decimal.Decimal(1972)
+   Decimal("1972")
+   >>> decimal.Decimal("1.1")
+   Decimal("1.1")
+
+You can also provide tuples containing the sign, the mantissa represented  as a
+tuple of decimal digits, and the exponent::
+
+   >>> decimal.Decimal((1, (1, 4, 7, 5), -2))
+   Decimal("-14.75")
+
+Cautionary note: the sign bit is a Boolean value, so 0 is positive and 1 is
+negative.
+
+Converting from floating-point numbers poses a bit of a problem: should the FP
+number representing 1.1 turn into the decimal number for exactly 1.1, or for 1.1
+plus whatever inaccuracies are introduced? The decision was to dodge the issue
+and leave such a conversion out of the API.  Instead, you should convert the
+floating-point number into a string using the desired precision and pass the
+string to the :class:`Decimal` constructor::
+
+   >>> f = 1.1
+   >>> decimal.Decimal(str(f))
+   Decimal("1.1")
+   >>> decimal.Decimal('%.12f' % f)
+   Decimal("1.100000000000")
+
+Once you have :class:`Decimal` instances, you can perform the usual mathematical
+operations on them.  One limitation: exponentiation requires an integer
+exponent::
+
+   >>> a = decimal.Decimal('35.72')
+   >>> b = decimal.Decimal('1.73')
+   >>> a+b
+   Decimal("37.45")
+   >>> a-b
+   Decimal("33.99")
+   >>> a*b
+   Decimal("61.7956")
+   >>> a/b
+   Decimal("20.64739884393063583815028902")
+   >>> a ** 2
+   Decimal("1275.9184")
+   >>> a**b
+   Traceback (most recent call last):
+     ...
+   decimal.InvalidOperation: x ** (non-integer)
+
+You can combine :class:`Decimal` instances with integers, but not with floating-
+point numbers::
+
+   >>> a + 4
+   Decimal("39.72")
+   >>> a + 4.5
+   Traceback (most recent call last):
+     ...
+   TypeError: You can interact Decimal only with int, long or Decimal data types.
+   >>>
+
+:class:`Decimal` numbers can be used with the :mod:`math` and :mod:`cmath`
+modules, but note that they'll be immediately converted to  floating-point
+numbers before the operation is performed, resulting in a possible loss of
+precision and accuracy.  You'll also get back a regular floating-point number
+and not a :class:`Decimal`.   ::
+
+   >>> import math, cmath
+   >>> d = decimal.Decimal('123456789012.345')
+   >>> math.sqrt(d)
+   351364.18288201344
+   >>> cmath.sqrt(-d)
+   351364.18288201344j
+
+:class:`Decimal` instances have a :meth:`sqrt` method that returns a
+:class:`Decimal`, but if you need other things such as trigonometric functions
+you'll have to implement them. ::
+
+   >>> d.sqrt()
+   Decimal("351364.1828820134592177245001")
+
+
+The :class:`Context` type
+-------------------------
+
+Instances of the :class:`Context` class encapsulate several settings for
+decimal operations:
+
+* :attr:`prec` is the precision, the number of decimal places.
+
+* :attr:`rounding` specifies the rounding mode.  The :mod:`decimal` module has
+  constants for the various possibilities: :const:`ROUND_DOWN`,
+  :const:`ROUND_CEILING`,  :const:`ROUND_HALF_EVEN`, and various others.
+
+* :attr:`traps` is a dictionary specifying what happens on encountering certain
+  error conditions: either  an exception is raised or  a value is returned.  Some
+  examples of error conditions are division by zero, loss of precision, and
+  overflow.
+
+There's a thread-local default context available by calling :func:`getcontext`;
+you can change the properties of this context to alter the default precision,
+rounding, or trap handling.  The following example shows the effect of changing
+the precision of the default context::
+
+   >>> decimal.getcontext().prec
+   28
+   >>> decimal.Decimal(1) / decimal.Decimal(7)
+   Decimal("0.1428571428571428571428571429")
+   >>> decimal.getcontext().prec = 9 
+   >>> decimal.Decimal(1) / decimal.Decimal(7)
+   Decimal("0.142857143")
+
+The default action for error conditions is selectable; the module can either
+return a special value such as infinity or not-a-number, or exceptions can be
+raised::
+
+   >>> decimal.Decimal(1) / decimal.Decimal(0)
+   Traceback (most recent call last):
+     ...
+   decimal.DivisionByZero: x / 0
+   >>> decimal.getcontext().traps[decimal.DivisionByZero] = False
+   >>> decimal.Decimal(1) / decimal.Decimal(0)
+   Decimal("Infinity")
+   >>> 
+
+The :class:`Context` instance also has various methods for formatting  numbers
+such as :meth:`to_eng_string` and :meth:`to_sci_string`.
+
+For more information, see the documentation for the :mod:`decimal` module, which
+includes a quick-start tutorial and a reference.
+
+
+.. seealso::
+
+   :pep:`327` - Decimal Data Type
+      Written by Facundo Batista and implemented by Facundo Batista, Eric Price,
+      Raymond Hettinger, Aahz, and Tim Peters.
+
+   http://research.microsoft.com/~hollasch/cgindex/coding/ieeefloat.html
+      A more detailed overview of the IEEE-754 representation.
+
+   http://www.lahey.com/float.htm
+      The article uses Fortran code to illustrate many of the problems that floating-
+      point inaccuracy can cause.
+
+   http://www2.hursley.ibm.com/decimal/
+      A description of a decimal-based representation.  This representation is being
+      proposed as a standard, and underlies the new Python decimal type.  Much of this
+      material was written by Mike Cowlishaw, designer of the Rexx language.
+
+.. % ======================================================================
+
+
+PEP 328: Multi-line Imports
+===========================
+
+One language change is a small syntactic tweak aimed at making it easier to
+import many names from a module.  In a ``from module import names`` statement,
+*names* is a sequence of names separated by commas.  If the sequence is  very
+long, you can either write multiple imports from the same module, or you can use
+backslashes to escape the line endings like this::
+
+   from SimpleXMLRPCServer import SimpleXMLRPCServer,\
+               SimpleXMLRPCRequestHandler,\
+               CGIXMLRPCRequestHandler,\
+               resolve_dotted_attribute
+
+The syntactic change in Python 2.4 simply allows putting the names within
+parentheses.  Python ignores newlines within a parenthesized expression, so the
+backslashes are no longer needed::
+
+   from SimpleXMLRPCServer import (SimpleXMLRPCServer,
+                                   SimpleXMLRPCRequestHandler,
+                                   CGIXMLRPCRequestHandler,
+                                   resolve_dotted_attribute)
+
+The PEP also proposes that all :keyword:`import` statements be absolute imports,
+with a leading ``.`` character to indicate a relative import.  This part of the
+PEP was not implemented for Python 2.4, but was completed for Python 2.5.
+
+
+.. seealso::
+
+   :pep:`328` - Imports: Multi-Line and Absolute/Relative
+      Written by Aahz.  Multi-line imports were implemented by Dima Dorfman.
+
+.. % ======================================================================
+
+
+PEP 331: Locale-Independent Float/String Conversions
+====================================================
+
+The :mod:`locale` modules lets Python software select various conversions and
+display conventions that are localized to a particular country or language.
+However, the module was careful to not change the numeric locale because various
+functions in Python's implementation required that the numeric locale remain set
+to the ``'C'`` locale.  Often this was because the code was using the C
+library's :cfunc:`atof` function.
+
+Not setting the numeric locale caused trouble for extensions that used third-
+party C libraries, however, because they wouldn't have the correct locale set.
+The motivating example was GTK+, whose user interface widgets weren't displaying
+numbers in the current locale.
+
+The solution described in the PEP is to add three new functions to the Python
+API that perform ASCII-only conversions, ignoring the locale setting:
+
+* :cfunc:`PyOS_ascii_strtod(str, ptr)`  and :cfunc:`PyOS_ascii_atof(str, ptr)`
+  both convert a string to a C :ctype:`double`.
+
+* :cfunc:`PyOS_ascii_formatd(buffer, buf_len, format, d)` converts a
+  :ctype:`double` to an ASCII string.
+
+The code for these functions came from the GLib library
+(http://developer.gnome.org/arch/gtk/glib.html), whose developers kindly
+relicensed the relevant functions and donated them to the Python Software
+Foundation.  The :mod:`locale` module  can now change the numeric locale,
+letting extensions such as GTK+  produce the correct results.
+
+
+.. seealso::
+
+   :pep:`331` - Locale-Independent Float/String Conversions
+      Written by Christian R. Reis, and implemented by Gustavo Carneiro.
+
+.. % ======================================================================
+
+
+Other Language Changes
+======================
+
+Here are all of the changes that Python 2.4 makes to the core Python language.
+
+* Decorators for functions and methods were added (:pep:`318`).
+
+* Built-in :func:`set` and :func:`frozenset` types were  added (:pep:`218`).
+  Other new built-ins include the :func:`reversed(seq)` function (:pep:`322`).
+
+* Generator expressions were added (:pep:`289`).
+
+* Certain numeric expressions no longer return values restricted to 32 or 64
+  bits (:pep:`237`).
+
+* You can now put parentheses around the list of names in a ``from module import
+  names`` statement (:pep:`328`).
+
+* The :meth:`dict.update` method now accepts the same argument forms as the
+  :class:`dict` constructor.  This includes any mapping, any iterable of key/value
+  pairs, and keyword arguments. (Contributed by Raymond Hettinger.)
+
+* The string methods :meth:`ljust`, :meth:`rjust`, and :meth:`center` now take
+  an optional argument for specifying a fill character other than a space.
+  (Contributed by Raymond Hettinger.)
+
+* Strings also gained an :meth:`rsplit` method that works like the :meth:`split`
+  method but splits from the end of the string.   (Contributed by Sean
+  Reifschneider.) ::
+
+     >>> 'www.python.org'.split('.', 1)
+     ['www', 'python.org']
+     'www.python.org'.rsplit('.', 1)
+     ['www.python', 'org']        
+
+* Three keyword parameters, *cmp*, *key*, and *reverse*, were added to the
+  :meth:`sort` method of lists. These parameters make some common usages of
+  :meth:`sort` simpler. All of these parameters are optional.
+
+  For the *cmp* parameter, the value should be a comparison function that takes
+  two parameters and returns -1, 0, or +1 depending on how the parameters compare.
+  This function will then be used to sort the list.  Previously this was the only
+  parameter that could be provided to :meth:`sort`.
+
+  *key* should be a single-parameter function that takes a list element and
+  returns a comparison key for the element.  The list is then sorted using the
+  comparison keys.  The following example sorts a list case-insensitively::
+
+     >>> L = ['A', 'b', 'c', 'D']
+     >>> L.sort()                 # Case-sensitive sort
+     >>> L
+     ['A', 'D', 'b', 'c']
+     >>> # Using 'key' parameter to sort list
+     >>> L.sort(key=lambda x: x.lower())
+     >>> L
+     ['A', 'b', 'c', 'D']
+     >>> # Old-fashioned way
+     >>> L.sort(cmp=lambda x,y: cmp(x.lower(), y.lower()))
+     >>> L
+     ['A', 'b', 'c', 'D']
+
+  The last example, which uses the *cmp* parameter, is the old way to perform a
+  case-insensitive sort.  It works but is slower than using a *key* parameter.
+  Using *key* calls :meth:`lower` method once for each element in the list while
+  using *cmp* will call it twice for each comparison, so using *key* saves on
+  invocations of the :meth:`lower` method.
+
+  For simple key functions and comparison functions, it is often possible to avoid
+  a :keyword:`lambda` expression by using an unbound method instead.  For example,
+  the above case-insensitive sort is best written as::
+
+     >>> L.sort(key=str.lower)
+     >>> L
+     ['A', 'b', 'c', 'D']
+
+  Finally, the *reverse* parameter takes a Boolean value.  If the value is true,
+  the list will be sorted into reverse order. Instead of ``L.sort() ;
+  L.reverse()``, you can now write ``L.sort(reverse=True)``.
+
+  The results of sorting are now guaranteed to be stable.  This means that two
+  entries with equal keys will be returned in the same order as they were input.
+  For example, you can sort a list of people by name, and then sort the list by
+  age, resulting in a list sorted by age where people with the same age are in
+  name-sorted order.
+
+  (All changes to :meth:`sort` contributed by Raymond Hettinger.)
+
+* There is a new built-in function :func:`sorted(iterable)` that works like the
+  in-place :meth:`list.sort` method but can be used in expressions.  The
+  differences are:
+
+* the input may be any iterable;
+
+* a newly formed copy is sorted, leaving the original intact; and
+
+* the expression returns the new sorted copy
+
+  ::
+
+     >>> L = [9,7,8,3,2,4,1,6,5]
+     >>> [10+i for i in sorted(L)]       # usable in a list comprehension
+     [11, 12, 13, 14, 15, 16, 17, 18, 19]
+     >>> L                               # original is left unchanged
+     [9,7,8,3,2,4,1,6,5]
+     >>> sorted('Monty Python')          # any iterable may be an input
+     [' ', 'M', 'P', 'h', 'n', 'n', 'o', 'o', 't', 't', 'y', 'y']
+
+     >>> # List the contents of a dict sorted by key values
+     >>> colormap = dict(red=1, blue=2, green=3, black=4, yellow=5)
+     >>> for k, v in sorted(colormap.iteritems()):
+     ...     print k, v
+     ...
+     black 4
+     blue 2
+     green 3
+     red 1
+     yellow 5
+
+  (Contributed by Raymond Hettinger.)
+
+* Integer operations will no longer trigger an :exc:`OverflowWarning`. The
+  :exc:`OverflowWarning` warning will disappear in Python 2.5.
+
+* The interpreter gained a new switch, :option:`-m`, that takes a name, searches
+  for the corresponding  module on ``sys.path``, and runs the module as a script.
+  For example,  you can now run the Python profiler with ``python -m profile``.
+  (Contributed by Nick Coghlan.)
+
+* The :func:`eval(expr, globals, locals)` and :func:`execfile(filename, globals,
+  locals)` functions and the :keyword:`exec` statement now accept any mapping type
+  for the *locals* parameter.  Previously this had to be a regular Python
+  dictionary.  (Contributed by Raymond Hettinger.)
+
+* The :func:`zip` built-in function and :func:`itertools.izip` now return an
+  empty list if called with no arguments. Previously they raised a
+  :exc:`TypeError` exception.  This makes them more suitable for use with variable
+  length argument lists::
+
+     >>> def transpose(array):
+     ...    return zip(*array)
+     ...
+     >>> transpose([(1,2,3), (4,5,6)])
+     [(1, 4), (2, 5), (3, 6)]
+     >>> transpose([])
+     []
+
+  (Contributed by Raymond Hettinger.)
+
+* Encountering a failure while importing a module no longer leaves a partially-
+  initialized module object in ``sys.modules``.  The incomplete module object left
+  behind would fool further imports of the same module into succeeding, leading to
+  confusing errors.   (Fixed by Tim Peters.)
+
+* :const:`None` is now a constant; code that binds a new value to  the name
+  ``None`` is now a syntax error. (Contributed by Raymond Hettinger.)
+
+.. % ======================================================================
+
+
+Optimizations
+-------------
+
+* The inner loops for list and tuple slicing were optimized and now run about
+  one-third faster.  The inner loops for dictionaries were also optimized,
+  resulting in performance boosts for :meth:`keys`, :meth:`values`, :meth:`items`,
+  :meth:`iterkeys`, :meth:`itervalues`, and :meth:`iteritems`. (Contributed by
+  Raymond Hettinger.)
+
+* The machinery for growing and shrinking lists was optimized for speed and for
+  space efficiency.  Appending and popping from lists now runs faster due to more
+  efficient code paths and less frequent use of the underlying system
+  :cfunc:`realloc`.  List comprehensions also benefit.   :meth:`list.extend` was
+  also optimized and no longer converts its argument into a temporary list before
+  extending the base list.  (Contributed by Raymond Hettinger.)
+
+* :func:`list`, :func:`tuple`, :func:`map`, :func:`filter`, and :func:`zip` now
+  run several times faster with non-sequence arguments that supply a
+  :meth:`__len__` method.  (Contributed by Raymond Hettinger.)
+
+* The methods :meth:`list.__getitem__`, :meth:`dict.__getitem__`, and
+  :meth:`dict.__contains__` are are now implemented as :class:`method_descriptor`
+  objects rather than :class:`wrapper_descriptor` objects.  This form of  access
+  doubles their performance and makes them more suitable for use as arguments to
+  functionals: ``map(mydict.__getitem__, keylist)``. (Contributed by Raymond
+  Hettinger.)
+
+* Added a new opcode, ``LIST_APPEND``, that simplifies the generated bytecode
+  for list comprehensions and speeds them up by about a third.  (Contributed by
+  Raymond Hettinger.)
+
+* The peephole bytecode optimizer has been improved to  produce shorter, faster
+  bytecode; remarkably, the resulting bytecode is  more readable.  (Enhanced by
+  Raymond Hettinger.)
+
+* String concatenations in statements of the form ``s = s + "abc"`` and ``s +=
+  "abc"`` are now performed more efficiently in certain circumstances.  This
+  optimization won't be present in other Python implementations such as Jython, so
+  you shouldn't rely on it; using the :meth:`join` method of strings is still
+  recommended when you want to efficiently glue a large number of strings
+  together. (Contributed by Armin Rigo.)
+
+The net result of the 2.4 optimizations is that Python 2.4 runs the pystone
+benchmark around 5% faster than Python 2.3 and 35% faster than Python 2.2.
+(pystone is not a particularly good benchmark, but it's the most commonly used
+measurement of Python's performance.  Your own applications may show greater or
+smaller benefits from Python 2.4.)
+
+.. % pystone is almost useless for comparing different versions of Python;
+.. % instead, it excels at predicting relative Python performance on
+.. % different machines.
+.. % So, this section would be more informative if it used other tools
+.. % such as pybench and parrotbench.  For a more application oriented
+.. % benchmark, try comparing the timings of test_decimal.py under 2.3
+.. % and 2.4.
+
+.. % ======================================================================
+
+
+New, Improved, and Deprecated Modules
+=====================================
+
+As usual, Python's standard library received a number of enhancements and bug
+fixes.  Here's a partial list of the most notable changes, sorted alphabetically
+by module name. Consult the :file:`Misc/NEWS` file in the source tree for a more
+complete list of changes, or look through the CVS logs for all the details.
+
+* The :mod:`asyncore` module's :func:`loop` function now has a *count* parameter
+  that lets you perform a limited number of passes through the polling loop.  The
+  default is still to loop forever.
+
+* The :mod:`base64` module now has more complete RFC 3548 support for Base64,
+  Base32, and Base16 encoding and decoding, including optional case folding and
+  optional alternative alphabets. (Contributed by Barry Warsaw.)
+
+* The :mod:`bisect` module now has an underlying C implementation for improved
+  performance. (Contributed by Dmitry Vasiliev.)
+
+* The CJKCodecs collections of East Asian codecs, maintained by Hye-Shik Chang,
+  was integrated into 2.4.   The new encodings are:
+
+* Chinese (PRC): gb2312, gbk, gb18030, big5hkscs, hz
+
+* Chinese (ROC): big5, cp950
+
+* Japanese: cp932, euc-jis-2004, euc-jp, euc-jisx0213, iso-2022-jp,
+    iso-2022-jp-1, iso-2022-jp-2, iso-2022-jp-3, iso-2022-jp-ext, iso-2022-jp-2004,
+    shift-jis, shift-jisx0213, shift-jis-2004
+
+* Korean: cp949, euc-kr, johab, iso-2022-kr
+
+* Some other new encodings were added: HP Roman8,  ISO_8859-11, ISO_8859-16,
+  PCTP-154, and TIS-620.
+
+* The UTF-8 and UTF-16 codecs now cope better with receiving partial input.
+  Previously the :class:`StreamReader` class would try to read more data, making
+  it impossible to resume decoding from the stream.  The :meth:`read` method will
+  now return as much data as it can and future calls will resume decoding where
+  previous ones left off.  (Implemented by Walter Dörwald.)
+
+* There is a new :mod:`collections` module for  various specialized collection
+  datatypes.   Currently it contains just one type, :class:`deque`,  a double-
+  ended queue that supports efficiently adding and removing elements from either
+  end::
+
+     >>> from collections import deque
+     >>> d = deque('ghi')        # make a new deque with three items
+     >>> d.append('j')           # add a new entry to the right side
+     >>> d.appendleft('f')       # add a new entry to the left side
+     >>> d                       # show the representation of the deque
+     deque(['f', 'g', 'h', 'i', 'j'])
+     >>> d.pop()                 # return and remove the rightmost item
+     'j'
+     >>> d.popleft()             # return and remove the leftmost item
+     'f'
+     >>> list(d)                 # list the contents of the deque
+     ['g', 'h', 'i']
+     >>> 'h' in d                # search the deque
+     True  
+
+  Several modules, such as the :mod:`Queue` and :mod:`threading` modules, now take
+  advantage of :class:`collections.deque` for improved performance.  (Contributed
+  by Raymond Hettinger.)
+
+* The :mod:`ConfigParser` classes have been enhanced slightly. The :meth:`read`
+  method now returns a list of the files that were successfully parsed, and the
+  :meth:`set` method raises :exc:`TypeError` if passed a *value* argument that
+  isn't a string.   (Contributed by John Belmonte and David Goodger.)
+
+* The :mod:`curses` module now supports the ncurses extension
+  :func:`use_default_colors`.  On platforms where the terminal supports
+  transparency, this makes it possible to use a transparent background.
+  (Contributed by Jörg Lehmann.)
+
+* The :mod:`difflib` module now includes an :class:`HtmlDiff` class that creates
+  an HTML table showing a side by side comparison of two versions of a text.
+  (Contributed by Dan Gass.)
+
+* The :mod:`email` package was updated to version 3.0,  which dropped various
+  deprecated APIs and removes support for Python versions earlier than 2.3.  The
+  3.0 version of the package uses a new incremental parser for MIME messages,
+  available in the :mod:`email.FeedParser` module.  The new parser doesn't require
+  reading the entire message into memory, and doesn't throw exceptions if a
+  message is malformed; instead it records any problems in the  :attr:`defect`
+  attribute of the message.  (Developed by Anthony Baxter, Barry Warsaw, Thomas
+  Wouters, and others.)
+
+* The :mod:`heapq` module has been converted to C.  The resulting tenfold
+  improvement in speed makes the module suitable for handling high volumes of
+  data.  In addition, the module has two new functions :func:`nlargest` and
+  :func:`nsmallest` that use heaps to find the N largest or smallest values in a
+  dataset without the expense of a full sort.  (Contributed by Raymond Hettinger.)
+
+* The :mod:`httplib` module now contains constants for HTTP status codes defined
+  in various HTTP-related RFC documents.  Constants have names such as
+  :const:`OK`, :const:`CREATED`, :const:`CONTINUE`, and
+  :const:`MOVED_PERMANENTLY`; use pydoc to get a full list.  (Contributed by
+  Andrew Eland.)
+
+* The :mod:`imaplib` module now supports IMAP's THREAD command (contributed by
+  Yves Dionne) and new :meth:`deleteacl` and :meth:`myrights` methods (contributed
+  by Arnaud Mazin).
+
+* The :mod:`itertools` module gained a :func:`groupby(iterable[, *func*])`
+  function. *iterable* is something that can be iterated over to return a stream
+  of elements, and the optional *func* parameter is a function that takes an
+  element and returns a key value; if omitted, the key is simply the element
+  itself.  :func:`groupby` then groups the elements into subsequences which have
+  matching values of the key, and returns a series of 2-tuples containing the key
+  value and an iterator over the subsequence.
+
+  Here's an example to make this clearer.  The *key* function simply returns
+  whether a number is even or odd, so the result of :func:`groupby` is to return
+  consecutive runs of odd or even numbers. ::
+
+     >>> import itertools
+     >>> L = [2, 4, 6, 7, 8, 9, 11, 12, 14]
+     >>> for key_val, it in itertools.groupby(L, lambda x: x % 2):
+     ...    print key_val, list(it)
+     ... 
+     0 [2, 4, 6]
+     1 [7]
+     0 [8]
+     1 [9, 11]
+     0 [12, 14]
+     >>> 
+
+  :func:`groupby` is typically used with sorted input.  The logic for
+  :func:`groupby` is similar to the Unix ``uniq`` filter which makes it handy for
+  eliminating, counting, or identifying duplicate elements::
+
+     >>> word = 'abracadabra'
+     >>> letters = sorted(word)   # Turn string into a sorted list of letters
+     >>> letters 
+     ['a', 'a', 'a', 'a', 'a', 'b', 'b', 'c', 'd', 'r', 'r']
+     >>> for k, g in itertools.groupby(letters):
+     ...    print k, list(g)
+     ... 
+     a ['a', 'a', 'a', 'a', 'a']
+     b ['b', 'b']
+     c ['c']
+     d ['d']
+     r ['r', 'r']
+     >>> # List unique letters
+     >>> [k for k, g in groupby(letters)]                     
+     ['a', 'b', 'c', 'd', 'r']
+     >>> # Count letter occurrences
+     >>> [(k, len(list(g))) for k, g in groupby(letters)]     
+     [('a', 5), ('b', 2), ('c', 1), ('d', 1), ('r', 2)]
+
+  (Contributed by Hye-Shik Chang.)
+
+* :mod:`itertools` also gained a function named :func:`tee(iterator, N)` that
+  returns *N* independent iterators that replicate *iterator*.  If *N* is omitted,
+  the default is 2. ::
+
+     >>> L = [1,2,3]
+     >>> i1, i2 = itertools.tee(L)
+     >>> i1,i2
+     (<itertools.tee object at 0x402c2080>, <itertools.tee object at 0x402c2090>)
+     >>> list(i1)               # Run the first iterator to exhaustion
+     [1, 2, 3]
+     >>> list(i2)               # Run the second iterator to exhaustion
+     [1, 2, 3]
+
+  Note that :func:`tee` has to keep copies of the values returned  by the
+  iterator; in the worst case, it may need to keep all of them.   This should
+  therefore be used carefully if the leading iterator can run far ahead of the
+  trailing iterator in a long stream of inputs. If the separation is large, then
+  you might as well use  :func:`list` instead.  When the iterators track closely
+  with one another, :func:`tee` is ideal.  Possible applications include
+  bookmarking, windowing, or lookahead iterators. (Contributed by Raymond
+  Hettinger.)
+
+* A number of functions were added to the :mod:`locale`  module, such as
+  :func:`bind_textdomain_codeset` to specify a particular encoding and a family of
+  :func:`l\*gettext` functions that return messages in the chosen encoding.
+  (Contributed by Gustavo Niemeyer.)
+
+* Some keyword arguments were added to the :mod:`logging` package's
+  :func:`basicConfig` function to simplify log configuration.  The default
+  behavior is to log messages to standard error, but various keyword arguments can
+  be specified to log to a particular file, change the logging format, or set the
+  logging level. For example::
+
+     import logging
+     logging.basicConfig(filename='/var/log/application.log',
+         level=0,  # Log all messages
+         format='%(levelname):%(process):%(thread):%(message)')	            
+
+  Other additions to the :mod:`logging` package include a :meth:`log(level, msg)`
+  convenience method, as well as a :class:`TimedRotatingFileHandler` class that
+  rotates its log files at a timed interval.  The module already had
+  :class:`RotatingFileHandler`, which rotated logs once the file exceeded a
+  certain size.  Both classes derive from a new :class:`BaseRotatingHandler` class
+  that can be used to implement other rotating handlers.
+
+  (Changes implemented by Vinay Sajip.)
+
+* The :mod:`marshal` module now shares interned strings on unpacking a  data
+  structure.  This may shrink the size of certain pickle strings, but the primary
+  effect is to make :file:`.pyc` files significantly smaller. (Contributed by
+  Martin von Löwis.)
+
+* The :mod:`nntplib` module's :class:`NNTP` class gained :meth:`description` and
+  :meth:`descriptions` methods to retrieve  newsgroup descriptions for a single
+  group or for a range of groups. (Contributed by Jürgen A. Erhard.)
+
+* Two new functions were added to the :mod:`operator` module,
+  :func:`attrgetter(attr)` and :func:`itemgetter(index)`. Both functions return
+  callables that take a single argument and return the corresponding attribute or
+  item; these callables make excellent data extractors when used with :func:`map`
+  or :func:`sorted`.  For example::
+
+     >>> L = [('c', 2), ('d', 1), ('a', 4), ('b', 3)]
+     >>> map(operator.itemgetter(0), L)
+     ['c', 'd', 'a', 'b']
+     >>> map(operator.itemgetter(1), L)
+     [2, 1, 4, 3]
+     >>> sorted(L, key=operator.itemgetter(1)) # Sort list by second tuple item
+     [('d', 1), ('c', 2), ('b', 3), ('a', 4)]
+
+  (Contributed by Raymond Hettinger.)
+
+* The :mod:`optparse` module was updated in various ways.  The module now passes
+  its messages through :func:`gettext.gettext`, making it possible to
+  internationalize Optik's help and error messages.  Help messages for options can
+  now include the string ``'%default'``, which will be replaced by the option's
+  default value.  (Contributed by Greg Ward.)
+
+* The long-term plan is to deprecate the :mod:`rfc822` module in some future
+  Python release in favor of the :mod:`email` package. To this end, the
+  :func:`email.Utils.formatdate` function has been changed to make it usable as a
+  replacement for :func:`rfc822.formatdate`.  You may want to write new e-mail
+  processing code with this in mind.  (Change implemented by Anthony Baxter.)
+
+* A new :func:`urandom(n)` function was added to the :mod:`os` module, returning
+  a string containing *n* bytes of random data.  This function provides access to
+  platform-specific sources of randomness such as :file:`/dev/urandom` on Linux or
+  the Windows CryptoAPI.  (Contributed by Trevor Perrin.)
+
+* Another new function: :func:`os.path.lexists(path)`  returns true if the file
+  specified by *path* exists, whether or not it's a symbolic link.  This differs
+  from the existing :func:`os.path.exists(path)` function, which returns false if
+  *path* is a symlink that points to a destination that doesn't exist.
+  (Contributed by Beni Cherniavsky.)
+
+* A new :func:`getsid` function was added to the :mod:`posix` module that
+  underlies the :mod:`os` module. (Contributed by J. Raynor.)
+
+* The :mod:`poplib` module now supports POP over SSL.  (Contributed by Hector
+  Urtubia.)
+
+* The :mod:`profile` module can now profile C extension functions. (Contributed
+  by Nick Bastin.)
+
+* The :mod:`random` module has a new method called :meth:`getrandbits(N)` that
+  returns a long integer *N* bits in length.  The existing :meth:`randrange`
+  method now uses :meth:`getrandbits` where appropriate, making generation of
+  arbitrarily large random numbers more efficient.  (Contributed by Raymond
+  Hettinger.)
+
+* The regular expression language accepted by the :mod:`re` module was extended
+  with simple conditional expressions, written as ``(?(group)A|B)``.  *group* is
+  either a numeric group ID or a group name defined with ``(?P<group>...)``
+  earlier in the expression.  If the specified group matched, the regular
+  expression pattern *A* will be tested against the string; if the group didn't
+  match, the pattern *B* will be used instead. (Contributed by Gustavo Niemeyer.)
+
+* The :mod:`re` module is also no longer recursive, thanks to a massive amount
+  of work by Gustavo Niemeyer.  In a recursive regular expression engine, certain
+  patterns result in a large amount of C stack space being consumed, and it was
+  possible to overflow the stack. For example, if you matched a 30000-byte string
+  of ``a`` characters against the expression ``(a|b)+``, one stack frame was
+  consumed per character.  Python 2.3 tried to check for stack overflow and raise
+  a :exc:`RuntimeError` exception, but certain patterns could sidestep the
+  checking and if you were unlucky Python could segfault. Python 2.4's regular
+  expression engine can match this pattern without problems.
+
+* The :mod:`signal` module now performs tighter error-checking on the parameters
+  to the :func:`signal.signal` function.  For example, you can't set a handler on
+  the :const:`SIGKILL` signal; previous versions of Python would quietly accept
+  this, but 2.4 will raise a :exc:`RuntimeError` exception.
+
+* Two new functions were added to the :mod:`socket` module. :func:`socketpair`
+  returns a pair of connected sockets and :func:`getservbyport(port)` looks up the
+  service name for a given port number. (Contributed by Dave Cole and Barry
+  Warsaw.)
+
+* The :func:`sys.exitfunc` function has been deprecated.  Code should be using
+  the existing :mod:`atexit` module, which correctly handles calling multiple exit
+  functions.  Eventually :func:`sys.exitfunc` will become a purely internal
+  interface, accessed only by :mod:`atexit`.
+
+* The :mod:`tarfile` module now generates GNU-format tar files by default.
+  (Contributed by Lars Gustaebel.)
+
+* The :mod:`threading` module now has an elegantly simple way to support
+  thread-local data.  The module contains a :class:`local` class whose attribute
+  values are local to different threads. ::
+
+     import threading
+
+     data = threading.local()
+     data.number = 42
+     data.url = ('www.python.org', 80)
+
+  Other threads can assign and retrieve their own values for the :attr:`number`
+  and :attr:`url` attributes.  You can subclass :class:`local` to initialize
+  attributes or to add methods. (Contributed by Jim Fulton.)
+
+* The :mod:`timeit` module now automatically disables periodic garbage
+  collection during the timing loop.  This change makes consecutive timings more
+  comparable.  (Contributed by Raymond Hettinger.)
+
+* The :mod:`weakref` module now supports a wider variety of objects including
+  Python functions, class instances, sets, frozensets, deques, arrays, files,
+  sockets, and regular expression pattern objects. (Contributed by Raymond
+  Hettinger.)
+
+* The :mod:`xmlrpclib` module now supports a multi-call extension for
+  transmitting multiple XML-RPC calls in a single HTTP operation. (Contributed by
+  Brian Quinlan.)
+
+* The :mod:`mpz`, :mod:`rotor`, and :mod:`xreadlines` modules have  been
+  removed.
+
+.. % ======================================================================
+.. % whole new modules get described in subsections here
+.. % =====================
+
+
+cookielib
+---------
+
+The :mod:`cookielib` library supports client-side handling for HTTP cookies,
+mirroring the :mod:`Cookie` module's server-side cookie support. Cookies are
+stored in cookie jars; the library transparently stores cookies offered by the
+web server in the cookie jar, and fetches the cookie from the jar when
+connecting to the server. As in web browsers, policy objects control whether
+cookies are accepted or not.
+
+In order to store cookies across sessions, two implementations of cookie jars
+are provided: one that stores cookies in the Netscape format so applications can
+use the Mozilla or Lynx cookie files, and one that stores cookies in the same
+format as the Perl libwww library.
+
+:mod:`urllib2` has been changed to interact with :mod:`cookielib`:
+:class:`HTTPCookieProcessor` manages a cookie jar that is used when accessing
+URLs.
+
+This module was contributed by John J. Lee.
+
+.. % ==================
+
+
+doctest
+-------
+
+The :mod:`doctest` module underwent considerable refactoring thanks to Edward
+Loper and Tim Peters.  Testing can still be as simple as running
+:func:`doctest.testmod`, but the refactorings allow customizing the module's
+operation in various ways
+
+The new :class:`DocTestFinder` class extracts the tests from a given  object's
+docstrings::
+
+   def f (x, y):
+       """>>> f(2,2)
+   4
+   >>> f(3,2)
+   6
+       """
+       return x*y
+
+   finder = doctest.DocTestFinder()
+
+   # Get list of DocTest instances
+   tests = finder.find(f)
+
+The new :class:`DocTestRunner` class then runs individual tests and can produce
+a summary of the results::
+
+   runner = doctest.DocTestRunner()
+   for t in tests:
+       tried, failed = runner.run(t)
+
+   runner.summarize(verbose=1)
+
+The above example produces the following output::
+
+   1 items passed all tests:
+      2 tests in f
+   2 tests in 1 items.
+   2 passed and 0 failed.
+   Test passed.
+
+:class:`DocTestRunner` uses an instance of the :class:`OutputChecker` class to
+compare the expected output with the actual output.  This class takes a number
+of different flags that customize its behaviour; ambitious users can also write
+a completely new subclass of :class:`OutputChecker`.
+
+The default output checker provides a number of handy features. For example,
+with the :const:`doctest.ELLIPSIS` option flag, an ellipsis (``...``) in the
+expected output matches any substring,  making it easier to accommodate outputs
+that vary in minor ways::
+
+   def o (n):
+       """>>> o(1)
+   <__main__.C instance at 0x...>
+   >>>
+   """
+
+Another special string, ``<BLANKLINE>``, matches a blank line::
+
+   def p (n):
+       """>>> p(1)
+   <BLANKLINE>
+   >>>
+   """
+
+Another new capability is producing a diff-style display of the output by
+specifying the :const:`doctest.REPORT_UDIFF` (unified diffs),
+:const:`doctest.REPORT_CDIFF` (context diffs), or :const:`doctest.REPORT_NDIFF`
+(delta-style) option flags.  For example::
+
+   def g (n):
+       """>>> g(4)
+   here
+   is
+   a
+   lengthy
+   >>>"""
+       L = 'here is a rather lengthy list of words'.split()
+       for word in L[:n]:
+           print word
+
+Running the above function's tests with :const:`doctest.REPORT_UDIFF` specified,
+you get the following output::
+
+   **********************************************************************
+   File ``t.py'', line 15, in g
+   Failed example:
+       g(4)
+   Differences (unified diff with -expected +actual):
+       @@ -2,3 +2,3 @@
+        is
+        a
+       -lengthy
+       +rather
+   **********************************************************************
+
+.. % ======================================================================
+
+
+Build and C API Changes
+=======================
+
+Some of the changes to Python's build process and to the C API are:
+
+* Three new convenience macros were added for common return values from
+  extension functions: :cmacro:`Py_RETURN_NONE`, :cmacro:`Py_RETURN_TRUE`, and
+  :cmacro:`Py_RETURN_FALSE`. (Contributed by Brett Cannon.)
+
+* Another new macro, :cmacro:`Py_CLEAR(obj)`,  decreases the reference count of
+  *obj* and sets *obj* to the null pointer.  (Contributed by Jim Fulton.)
+
+* A new function, :cfunc:`PyTuple_Pack(N, obj1, obj2, ..., objN)`, constructs
+  tuples from a variable length argument list of Python objects.  (Contributed by
+  Raymond Hettinger.)
+
+* A new function, :cfunc:`PyDict_Contains(d, k)`, implements fast dictionary
+  lookups without masking exceptions raised during the look-up process.
+  (Contributed by Raymond Hettinger.)
+
+* The :cmacro:`Py_IS_NAN(X)` macro returns 1 if  its float or double argument
+  *X* is a NaN.   (Contributed by Tim Peters.)
+
+* C code can avoid unnecessary locking by using the new
+  :cfunc:`PyEval_ThreadsInitialized` function to tell  if any thread operations
+  have been performed.  If this function  returns false, no lock operations are
+  needed. (Contributed by Nick Coghlan.)
+
+* A new function, :cfunc:`PyArg_VaParseTupleAndKeywords`, is the same as
+  :cfunc:`PyArg_ParseTupleAndKeywords` but takes a  :ctype:`va_list` instead of a
+  number of arguments. (Contributed by Greg Chapman.)
+
+* A new method flag, :const:`METH_COEXISTS`, allows a function defined in slots
+  to co-exist with a :ctype:`PyCFunction` having the same name.  This can halve
+  the access time for a method such as :meth:`set.__contains__`.  (Contributed by
+  Raymond Hettinger.)
+
+* Python can now be built with additional profiling for the interpreter itself,
+  intended as an aid to people developing the Python core.  Providing
+  :option:`----enable-profiling` to the :program:`configure` script will let you
+  profile the interpreter with :program:`gprof`, and providing the
+  :option:`----with-tsc` switch enables profiling using the Pentium's Time-Stamp-
+  Counter register.  Note that the :option:`----with-tsc` switch is slightly
+  misnamed, because the profiling feature also works on the PowerPC platform,
+  though that processor architecture doesn't call that register "the TSC
+  register".  (Contributed by Jeremy Hylton.)
+
+* The :ctype:`tracebackobject` type has been renamed to
+  :ctype:`PyTracebackObject`.
+
+.. % ======================================================================
+
+
+Port-Specific Changes
+---------------------
+
+* The Windows port now builds under MSVC++ 7.1 as well as version 6.
+  (Contributed by Martin von Löwis.)
+
+.. % ======================================================================
+
+
+Porting to Python 2.4
+=====================
+
+This section lists previously described changes that may require changes to your
+code:
+
+* Left shifts and hexadecimal/octal constants that are too  large no longer
+  trigger a :exc:`FutureWarning` and return  a value limited to 32 or 64 bits;
+  instead they return a long integer.
+
+* Integer operations will no longer trigger an :exc:`OverflowWarning`. The
+  :exc:`OverflowWarning` warning will disappear in Python 2.5.
+
+* The :func:`zip` built-in function and :func:`itertools.izip` now return  an
+  empty list instead of raising a :exc:`TypeError` exception if called with no
+  arguments.
+
+* You can no longer compare the :class:`date` and :class:`datetime` instances
+  provided by the :mod:`datetime` module.  Two  instances of different classes
+  will now always be unequal, and  relative comparisons (``<``, ``>``) will raise
+  a :exc:`TypeError`.
+
+* :func:`dircache.listdir` now passes exceptions to the caller instead of
+  returning empty lists.
+
+* :func:`LexicalHandler.startDTD` used to receive the public and system IDs in
+  the wrong order.  This has been corrected; applications relying on the wrong
+  order need to be fixed.
+
+* :func:`fcntl.ioctl` now warns if the *mutate*  argument is omitted and
+  relevant.
+
+* The :mod:`tarfile` module now generates GNU-format tar files by default.
+
+* Encountering a failure while importing a module no longer leaves a partially-
+  initialized module object in ``sys.modules``.
+
+* :const:`None` is now a constant; code that binds a new value to  the name
+  ``None`` is now a syntax error.
+
+* The :func:`signals.signal` function now raises a :exc:`RuntimeError` exception
+  for certain illegal values; previously these errors would pass silently.  For
+  example, you can no longer set a handler on the :const:`SIGKILL` signal.
+
+.. % ======================================================================
+
+
+.. _acks:
+
+Acknowledgements
+================
+
+The author would like to thank the following people for offering suggestions,
+corrections and assistance with various drafts of this article: Koray Can, Hye-
+Shik Chang, Michael Dyck, Raymond Hettinger, Brian Hurt, Hamish Lawson, Fredrik
+Lundh, Sean Reifschneider, Sadruddin Rejeb.
+
diff --git a/Doc/whatsnew/2.5.rst b/Doc/whatsnew/2.5.rst
new file mode 100644
index 0000000..f0429ec
--- /dev/null
+++ b/Doc/whatsnew/2.5.rst
@@ -0,0 +1,2286 @@
+****************************
+  What's New in Python 2.5  
+****************************
+
+:Author: A.M. Kuchling
+
+.. |release| replace:: 1.01
+
+.. % $Id: whatsnew25.tex 56611 2007-07-29 08:26:10Z georg.brandl $
+.. % Fix XXX comments
+
+This article explains the new features in Python 2.5.  The final release of
+Python 2.5 is scheduled for August 2006; :pep:`356` describes the planned
+release schedule.
+
+The changes in Python 2.5 are an interesting mix of language and library
+improvements. The library enhancements will be more important to Python's user
+community, I think, because several widely-useful packages were added.  New
+modules include ElementTree for XML processing (section :ref:`module-etree`),
+the SQLite database module (section :ref:`module-sqlite`), and the :mod:`ctypes`
+module for calling C functions (section :ref:`module-ctypes`).
+
+The language changes are of middling significance.  Some pleasant new features
+were added, but most of them aren't features that you'll use every day.
+Conditional expressions were finally added to the language using a novel syntax;
+see section :ref:`pep-308`.  The new ':keyword:`with`' statement will make
+writing cleanup code easier (section :ref:`pep-343`).  Values can now be passed
+into generators (section :ref:`pep-342`).  Imports are now visible as either
+absolute or relative (section :ref:`pep-328`).  Some corner cases of exception
+handling are handled better (section :ref:`pep-341`).  All these improvements
+are worthwhile, but they're improvements to one specific language feature or
+another; none of them are broad modifications to Python's semantics.
+
+As well as the language and library additions, other improvements and bugfixes
+were made throughout the source tree.  A search through the SVN change logs
+finds there were 353 patches applied and 458 bugs fixed between Python 2.4 and
+2.5.  (Both figures are likely to be underestimates.)
+
+This article doesn't try to be a complete specification of the new features;
+instead changes are briefly introduced using helpful examples.  For full
+details, you should always refer to the documentation for Python 2.5 at
+http://docs.python.org. If you want to understand the complete implementation
+and design rationale, refer to the PEP for a particular new feature.
+
+Comments, suggestions, and error reports for this document are welcome; please
+e-mail them to the author or open a bug in the Python bug tracker.
+
+.. % ======================================================================
+
+
+.. _pep-308:
+
+PEP 308: Conditional Expressions
+================================
+
+For a long time, people have been requesting a way to write conditional
+expressions, which are expressions that return value A or value B depending on
+whether a Boolean value is true or false.  A conditional expression lets you
+write a single assignment statement that has the same effect as the following::
+
+   if condition:
+       x = true_value
+   else:
+       x = false_value
+
+There have been endless tedious discussions of syntax on both python-dev and
+comp.lang.python.  A vote was even held that found the majority of voters wanted
+conditional expressions in some form, but there was no syntax that was preferred
+by a clear majority. Candidates included C's ``cond ? true_v : false_v``, ``if
+cond then true_v else false_v``, and 16 other variations.
+
+Guido van Rossum eventually chose a surprising syntax::
+
+   x = true_value if condition else false_value
+
+Evaluation is still lazy as in existing Boolean expressions, so the order of
+evaluation jumps around a bit.  The *condition* expression in the middle is
+evaluated first, and the *true_value* expression is evaluated only if the
+condition was true.  Similarly, the *false_value* expression is only evaluated
+when the condition is false.
+
+This syntax may seem strange and backwards; why does the condition go in the
+*middle* of the expression, and not in the front as in C's ``c ? x : y``?  The
+decision was checked by applying the new syntax to the modules in the standard
+library and seeing how the resulting code read.  In many cases where a
+conditional expression is used, one value seems to be the 'common case' and one
+value is an 'exceptional case', used only on rarer occasions when the condition
+isn't met.  The conditional syntax makes this pattern a bit more obvious::
+
+   contents = ((doc + '\n') if doc else '')
+
+I read the above statement as meaning "here *contents* is  usually assigned a
+value of ``doc+'\n'``; sometimes  *doc* is empty, in which special case an empty
+string is returned."   I doubt I will use conditional expressions very often
+where there  isn't a clear common and uncommon case.
+
+There was some discussion of whether the language should require surrounding
+conditional expressions with parentheses.  The decision was made to *not*
+require parentheses in the Python language's grammar, but as a matter of style I
+think you should always use them. Consider these two statements::
+
+   # First version -- no parens
+   level = 1 if logging else 0
+
+   # Second version -- with parens
+   level = (1 if logging else 0)
+
+In the first version, I think a reader's eye might group the statement into
+'level = 1', 'if logging', 'else 0', and think that the condition decides
+whether the assignment to *level* is performed.  The second version reads
+better, in my opinion, because it makes it clear that the assignment is always
+performed and the choice is being made between two values.
+
+Another reason for including the brackets: a few odd combinations of list
+comprehensions and lambdas could look like incorrect conditional expressions.
+See :pep:`308` for some examples.  If you put parentheses around your
+conditional expressions, you won't run into this case.
+
+
+.. seealso::
+
+   :pep:`308` - Conditional Expressions
+      PEP written by Guido van Rossum and Raymond D. Hettinger; implemented by Thomas
+      Wouters.
+
+.. % ======================================================================
+
+
+.. _pep-309:
+
+PEP 309: Partial Function Application
+=====================================
+
+The :mod:`functools` module is intended to contain tools for functional-style
+programming.
+
+One useful tool in this module is the :func:`partial` function. For programs
+written in a functional style, you'll sometimes want to construct variants of
+existing functions that have some of the parameters filled in.  Consider a
+Python function ``f(a, b, c)``; you could create a new function ``g(b, c)`` that
+was equivalent to ``f(1, b, c)``.  This is called "partial function
+application".
+
+:func:`partial` takes the arguments ``(function, arg1, arg2, ... kwarg1=value1,
+kwarg2=value2)``.  The resulting object is callable, so you can just call it to
+invoke *function* with the filled-in arguments.
+
+Here's a small but realistic example::
+
+   import functools
+
+   def log (message, subsystem):
+       "Write the contents of 'message' to the specified subsystem."
+       print '%s: %s' % (subsystem, message)
+       ...
+
+   server_log = functools.partial(log, subsystem='server')
+   server_log('Unable to open socket')
+
+Here's another example, from a program that uses PyGTK.  Here a context-
+sensitive pop-up menu is being constructed dynamically.  The callback provided
+for the menu option is a partially applied version of the :meth:`open_item`
+method, where the first argument has been provided. ::
+
+   ...
+   class Application:
+       def open_item(self, path):
+          ...
+       def init (self):
+           open_func = functools.partial(self.open_item, item_path)
+           popup_menu.append( ("Open", open_func, 1) )
+
+Another function in the :mod:`functools` module is the
+:func:`update_wrapper(wrapper, wrapped)` function that helps you write well-
+behaved decorators.  :func:`update_wrapper` copies the name, module, and
+docstring attribute to a wrapper function so that tracebacks inside the wrapped
+function are easier to understand.  For example, you might write::
+
+   def my_decorator(f):
+       def wrapper(*args, **kwds):
+           print 'Calling decorated function'
+           return f(*args, **kwds)
+       functools.update_wrapper(wrapper, f)
+       return wrapper
+
+:func:`wraps` is a decorator that can be used inside your own decorators to copy
+the wrapped function's information.  An alternate  version of the previous
+example would be::
+
+   def my_decorator(f):
+       @functools.wraps(f)
+       def wrapper(*args, **kwds):
+           print 'Calling decorated function'
+           return f(*args, **kwds)
+       return wrapper
+
+
+.. seealso::
+
+   :pep:`309` - Partial Function Application
+      PEP proposed and written by Peter Harris; implemented by Hye-Shik Chang and Nick
+      Coghlan, with adaptations by Raymond Hettinger.
+
+.. % ======================================================================
+
+
+.. _pep-314:
+
+PEP 314: Metadata for Python Software Packages v1.1
+===================================================
+
+Some simple dependency support was added to Distutils.  The :func:`setup`
+function now has ``requires``, ``provides``, and ``obsoletes`` keyword
+parameters.  When you build a source distribution using the ``sdist`` command,
+the dependency information will be recorded in the :file:`PKG-INFO` file.
+
+Another new keyword parameter is ``download_url``, which should be set to a URL
+for the package's source code.  This means it's now possible to look up an entry
+in the package index, determine the dependencies for a package, and download the
+required packages. ::
+
+   VERSION = '1.0'
+   setup(name='PyPackage', 
+         version=VERSION,
+         requires=['numarray', 'zlib (>=1.1.4)'],
+         obsoletes=['OldPackage']
+         download_url=('http://www.example.com/pypackage/dist/pkg-%s.tar.gz'
+                       % VERSION),
+        )
+
+Another new enhancement to the Python package index at
+http://cheeseshop.python.org is storing source and binary archives for a
+package.  The new :command:`upload` Distutils command will upload a package to
+the repository.
+
+Before a package can be uploaded, you must be able to build a distribution using
+the :command:`sdist` Distutils command.  Once that works, you can run ``python
+setup.py upload`` to add your package to the PyPI archive.  Optionally you can
+GPG-sign the package by supplying the :option:`--sign` and :option:`--identity`
+options.
+
+Package uploading was implemented by Martin von Löwis and Richard Jones.
+
+
+.. seealso::
+
+   :pep:`314` - Metadata for Python Software Packages v1.1
+      PEP proposed and written by A.M. Kuchling, Richard Jones, and Fred Drake;
+      implemented by Richard Jones and Fred Drake.
+
+.. % ======================================================================
+
+
+.. _pep-328:
+
+PEP 328: Absolute and Relative Imports
+======================================
+
+The simpler part of PEP 328 was implemented in Python 2.4: parentheses could now
+be used to enclose the names imported from a module using the ``from ... import
+...`` statement, making it easier to import many different names.
+
+The more complicated part has been implemented in Python 2.5: importing a module
+can be specified to use absolute or package-relative imports.  The plan is to
+move toward making absolute imports the default in future versions of Python.
+
+Let's say you have a package directory like this::
+
+   pkg/
+   pkg/__init__.py
+   pkg/main.py
+   pkg/string.py
+
+This defines a package named :mod:`pkg` containing the :mod:`pkg.main` and
+:mod:`pkg.string` submodules.
+
+Consider the code in the :file:`main.py` module.  What happens if it executes
+the statement ``import string``?  In Python 2.4 and earlier, it will first look
+in the package's directory to perform a relative import, finds
+:file:`pkg/string.py`, imports the contents of that file as the
+:mod:`pkg.string` module, and that module is bound to the name ``string`` in the
+:mod:`pkg.main` module's namespace.
+
+That's fine if :mod:`pkg.string` was what you wanted.  But what if you wanted
+Python's standard :mod:`string` module?  There's no clean way to ignore
+:mod:`pkg.string` and look for the standard module; generally you had to look at
+the contents of ``sys.modules``, which is slightly unclean.    Holger Krekel's
+:mod:`py.std` package provides a tidier way to perform imports from the standard
+library, ``import py ; py.std.string.join()``, but that package isn't available
+on all Python installations.
+
+Reading code which relies on relative imports is also less clear, because a
+reader may be confused about which module, :mod:`string` or :mod:`pkg.string`,
+is intended to be used.  Python users soon learned not to duplicate the names of
+standard library modules in the names of their packages' submodules, but you
+can't protect against having your submodule's name being used for a new module
+added in a future version of Python.
+
+In Python 2.5, you can switch :keyword:`import`'s behaviour to  absolute imports
+using a ``from __future__ import absolute_import`` directive.  This absolute-
+import behaviour will become the default in a future version (probably Python
+2.7).  Once absolute imports  are the default, ``import string`` will always
+find the standard library's version. It's suggested that users should begin
+using absolute imports as much as possible, so it's preferable to begin writing
+``from pkg import string`` in your code.
+
+Relative imports are still possible by adding a leading period  to the module
+name when using the ``from ... import`` form::
+
+   # Import names from pkg.string
+   from .string import name1, name2
+   # Import pkg.string
+   from . import string
+
+This imports the :mod:`string` module relative to the current package, so in
+:mod:`pkg.main` this will import *name1* and *name2* from :mod:`pkg.string`.
+Additional leading periods perform the relative import starting from the parent
+of the current package.  For example, code in the :mod:`A.B.C` module can do::
+
+   from . import D                 # Imports A.B.D
+   from .. import E                # Imports A.E
+   from ..F import G               # Imports A.F.G
+
+Leading periods cannot be used with the ``import modname``  form of the import
+statement, only the ``from ... import`` form.
+
+
+.. seealso::
+
+   :pep:`328` - Imports: Multi-Line and Absolute/Relative
+      PEP written by Aahz; implemented by Thomas Wouters.
+
+   http://codespeak.net/py/current/doc/index.html
+      The py library by Holger Krekel, which contains the :mod:`py.std` package.
+
+.. % ======================================================================
+
+
+.. _pep-338:
+
+PEP 338: Executing Modules as Scripts
+=====================================
+
+The :option:`-m` switch added in Python 2.4 to execute a module as a script
+gained a few more abilities.  Instead of being implemented in C code inside the
+Python interpreter, the switch now uses an implementation in a new module,
+:mod:`runpy`.
+
+The :mod:`runpy` module implements a more sophisticated import mechanism so that
+it's now possible to run modules in a package such as :mod:`pychecker.checker`.
+The module also supports alternative import mechanisms such as the
+:mod:`zipimport` module.  This means you can add a .zip archive's path to
+``sys.path`` and then use the :option:`-m` switch to execute code from the
+archive.
+
+
+.. seealso::
+
+   :pep:`338` - Executing modules as scripts
+      PEP written and  implemented by Nick Coghlan.
+
+.. % ======================================================================
+
+
+.. _pep-341:
+
+PEP 341: Unified try/except/finally
+===================================
+
+Until Python 2.5, the :keyword:`try` statement came in two flavours. You could
+use a :keyword:`finally` block to ensure that code is always executed, or one or
+more :keyword:`except` blocks to catch  specific exceptions.  You couldn't
+combine both :keyword:`except` blocks and a :keyword:`finally` block, because
+generating the right bytecode for the combined version was complicated and it
+wasn't clear what the semantics of the combined statement should be.
+
+Guido van Rossum spent some time working with Java, which does support the
+equivalent of combining :keyword:`except` blocks and a :keyword:`finally` block,
+and this clarified what the statement should mean.  In Python 2.5, you can now
+write::
+
+   try:
+       block-1 ...
+   except Exception1:
+       handler-1 ...
+   except Exception2:
+       handler-2 ...
+   else:
+       else-block
+   finally:
+       final-block 
+
+The code in *block-1* is executed.  If the code raises an exception, the various
+:keyword:`except` blocks are tested: if the exception is of class
+:class:`Exception1`, *handler-1* is executed; otherwise if it's of class
+:class:`Exception2`, *handler-2* is executed, and so forth.  If no exception is
+raised, the *else-block* is executed.
+
+No matter what happened previously, the *final-block* is executed once the code
+block is complete and any raised exceptions handled. Even if there's an error in
+an exception handler or the *else-block* and a new exception is raised, the code
+in the *final-block* is still run.
+
+
+.. seealso::
+
+   :pep:`341` - Unifying try-except and try-finally
+      PEP written by Georg Brandl;  implementation by Thomas Lee.
+
+.. % ======================================================================
+
+
+.. _pep-342:
+
+PEP 342: New Generator Features
+===============================
+
+Python 2.5 adds a simple way to pass values *into* a generator. As introduced in
+Python 2.3, generators only produce output; once a generator's code was invoked
+to create an iterator, there was no way to pass any new information into the
+function when its execution is resumed.  Sometimes the ability to pass in some
+information would be useful.  Hackish solutions to this include making the
+generator's code look at a global variable and then changing the global
+variable's value, or passing in some mutable object that callers then modify.
+
+To refresh your memory of basic generators, here's a simple example::
+
+   def counter (maximum):
+       i = 0
+       while i < maximum:
+           yield i
+           i += 1
+
+When you call ``counter(10)``, the result is an iterator that returns the values
+from 0 up to 9.  On encountering the :keyword:`yield` statement, the iterator
+returns the provided value and suspends the function's execution, preserving the
+local variables. Execution resumes on the following call to the iterator's
+:meth:`next` method, picking up after the :keyword:`yield` statement.
+
+In Python 2.3, :keyword:`yield` was a statement; it didn't return any value.  In
+2.5, :keyword:`yield` is now an expression, returning a value that can be
+assigned to a variable or otherwise operated on::
+
+   val = (yield i)
+
+I recommend that you always put parentheses around a :keyword:`yield` expression
+when you're doing something with the returned value, as in the above example.
+The parentheses aren't always necessary, but it's easier to always add them
+instead of having to remember when they're needed.
+
+(:pep:`342` explains the exact rules, which are that a :keyword:`yield`\
+-expression must always be parenthesized except when it occurs at the top-level
+expression on the right-hand side of an assignment.  This means you can write
+``val = yield i`` but have to use parentheses when there's an operation, as in
+``val = (yield i) + 12``.)
+
+Values are sent into a generator by calling its :meth:`send(value)` method.  The
+generator's code is then resumed and the :keyword:`yield` expression returns the
+specified *value*.  If the regular :meth:`next` method is called, the
+:keyword:`yield` returns :const:`None`.
+
+Here's the previous example, modified to allow changing the value of the
+internal counter. ::
+
+   def counter (maximum):
+       i = 0
+       while i < maximum:
+           val = (yield i)
+           # If value provided, change counter
+           if val is not None:
+               i = val
+           else:
+               i += 1
+
+And here's an example of changing the counter::
+
+   >>> it = counter(10)
+   >>> print it.next()
+   0
+   >>> print it.next()
+   1
+   >>> print it.send(8)
+   8
+   >>> print it.next()
+   9
+   >>> print it.next()
+   Traceback (most recent call last):
+     File ``t.py'', line 15, in ?
+       print it.next()
+   StopIteration
+
+:keyword:`yield` will usually return :const:`None`, so you should always check
+for this case.  Don't just use its value in expressions unless you're sure that
+the :meth:`send` method will be the only method used to resume your generator
+function.
+
+In addition to :meth:`send`, there are two other new methods on generators:
+
+* :meth:`throw(type, value=None, traceback=None)` is used to raise an exception
+  inside the generator; the exception is raised by the :keyword:`yield` expression
+  where the generator's execution is paused.
+
+* :meth:`close` raises a new :exc:`GeneratorExit` exception inside the generator
+  to terminate the iteration.  On receiving this exception, the generator's code
+  must either raise :exc:`GeneratorExit` or :exc:`StopIteration`.  Catching the
+  :exc:`GeneratorExit` exception and returning a value is illegal and will trigger
+  a :exc:`RuntimeError`; if the function raises some other exception, that
+  exception is propagated to the caller.  :meth:`close` will also be called by
+  Python's garbage collector when the generator is garbage-collected.
+
+  If you need to run cleanup code when a :exc:`GeneratorExit` occurs, I suggest
+  using a ``try: ... finally:`` suite instead of  catching :exc:`GeneratorExit`.
+
+The cumulative effect of these changes is to turn generators from one-way
+producers of information into both producers and consumers.
+
+Generators also become *coroutines*, a more generalized form of subroutines.
+Subroutines are entered at one point and exited at another point (the top of the
+function, and a :keyword:`return` statement), but coroutines can be entered,
+exited, and resumed at many different points (the :keyword:`yield` statements).
+We'll have to figure out patterns for using coroutines effectively in Python.
+
+The addition of the :meth:`close` method has one side effect that isn't obvious.
+:meth:`close` is called when a generator is garbage-collected, so this means the
+generator's code gets one last chance to run before the generator is destroyed.
+This last chance means that ``try...finally`` statements in generators can now
+be guaranteed to work; the :keyword:`finally` clause will now always get a
+chance to run.  The syntactic restriction that you couldn't mix :keyword:`yield`
+statements with a ``try...finally`` suite has therefore been removed.  This
+seems like a minor bit of language trivia, but using generators and
+``try...finally`` is actually necessary in order to implement the
+:keyword:`with` statement described by PEP 343.  I'll look at this new statement
+in the following  section.
+
+Another even more esoteric effect of this change: previously, the
+:attr:`gi_frame` attribute of a generator was always a frame object. It's now
+possible for :attr:`gi_frame` to be ``None`` once the generator has been
+exhausted.
+
+
+.. seealso::
+
+   :pep:`342` - Coroutines via Enhanced Generators
+      PEP written by  Guido van Rossum and Phillip J. Eby; implemented by Phillip J.
+      Eby.  Includes examples of  some fancier uses of generators as coroutines.
+
+      Earlier versions of these features were proposed in  :pep:`288` by Raymond
+      Hettinger and :pep:`325` by Samuele Pedroni.
+
+   http://en.wikipedia.org/wiki/Coroutine
+      The Wikipedia entry for  coroutines.
+
+   http://www.sidhe.org/~dan/blog/archives/000178.html
+      An explanation of coroutines from a Perl point of view, written by Dan Sugalski.
+
+.. % ======================================================================
+
+
+.. _pep-343:
+
+PEP 343: The 'with' statement
+=============================
+
+The ':keyword:`with`' statement clarifies code that previously would use
+``try...finally`` blocks to ensure that clean-up code is executed.  In this
+section, I'll discuss the statement as it will commonly be used.  In the next
+section, I'll examine the implementation details and show how to write objects
+for use with this statement.
+
+The ':keyword:`with`' statement is a new control-flow structure whose basic
+structure is::
+
+   with expression [as variable]:
+       with-block
+
+The expression is evaluated, and it should result in an object that supports the
+context management protocol (that is, has :meth:`__enter__` and :meth:`__exit__`
+methods.
+
+The object's :meth:`__enter__` is called before *with-block* is executed and
+therefore can run set-up code. It also may return a value that is bound to the
+name *variable*, if given.  (Note carefully that *variable* is *not* assigned
+the result of *expression*.)
+
+After execution of the *with-block* is finished, the object's :meth:`__exit__`
+method is called, even if the block raised an exception, and can therefore run
+clean-up code.
+
+To enable the statement in Python 2.5, you need to add the following directive
+to your module::
+
+   from __future__ import with_statement
+
+The statement will always be enabled in Python 2.6.
+
+Some standard Python objects now support the context management protocol and can
+be used with the ':keyword:`with`' statement. File objects are one example::
+
+   with open('/etc/passwd', 'r') as f:
+       for line in f:
+           print line
+           ... more processing code ...
+
+After this statement has executed, the file object in *f* will have been
+automatically closed, even if the :keyword:`for` loop raised an exception part-
+way through the block.
+
+.. note::
+
+   In this case, *f* is the same object created by :func:`open`, because
+   :meth:`file.__enter__` returns *self*.
+
+The :mod:`threading` module's locks and condition variables  also support the
+':keyword:`with`' statement::
+
+   lock = threading.Lock()
+   with lock:
+       # Critical section of code
+       ...
+
+The lock is acquired before the block is executed and always released once  the
+block is complete.
+
+The new :func:`localcontext` function in the :mod:`decimal` module makes it easy
+to save and restore the current decimal context, which encapsulates the desired
+precision and rounding characteristics for computations::
+
+   from decimal import Decimal, Context, localcontext
+
+   # Displays with default precision of 28 digits
+   v = Decimal('578')
+   print v.sqrt()
+
+   with localcontext(Context(prec=16)):
+       # All code in this block uses a precision of 16 digits.
+       # The original context is restored on exiting the block.
+       print v.sqrt()
+
+
+.. _context-managers:
+
+Writing Context Managers
+------------------------
+
+Under the hood, the ':keyword:`with`' statement is fairly complicated. Most
+people will only use ':keyword:`with`' in company with existing objects and
+don't need to know these details, so you can skip the rest of this section if
+you like.  Authors of new objects will need to understand the details of the
+underlying implementation and should keep reading.
+
+A high-level explanation of the context management protocol is:
+
+* The expression is evaluated and should result in an object called a "context
+  manager".  The context manager must have :meth:`__enter__` and :meth:`__exit__`
+  methods.
+
+* The context manager's :meth:`__enter__` method is called.  The value returned
+  is assigned to *VAR*.  If no ``'as VAR'`` clause is present, the value is simply
+  discarded.
+
+* The code in *BLOCK* is executed.
+
+* If *BLOCK* raises an exception, the :meth:`__exit__(type, value, traceback)`
+  is called with the exception details, the same values returned by
+  :func:`sys.exc_info`.  The method's return value controls whether the exception
+  is re-raised: any false value re-raises the exception, and ``True`` will result
+  in suppressing it.  You'll only rarely want to suppress the exception, because
+  if you do the author of the code containing the ':keyword:`with`' statement will
+  never realize anything went wrong.
+
+* If *BLOCK* didn't raise an exception,  the :meth:`__exit__` method is still
+  called, but *type*, *value*, and *traceback* are all ``None``.
+
+Let's think through an example.  I won't present detailed code but will only
+sketch the methods necessary for a database that supports transactions.
+
+(For people unfamiliar with database terminology: a set of changes to the
+database are grouped into a transaction.  Transactions can be either committed,
+meaning that all the changes are written into the database, or rolled back,
+meaning that the changes are all discarded and the database is unchanged.  See
+any database textbook for more information.)
+
+Let's assume there's an object representing a database connection. Our goal will
+be to let the user write code like this::
+
+   db_connection = DatabaseConnection()
+   with db_connection as cursor:
+       cursor.execute('insert into ...')
+       cursor.execute('delete from ...')
+       # ... more operations ...
+
+The transaction should be committed if the code in the block runs flawlessly or
+rolled back if there's an exception. Here's the basic interface for
+:class:`DatabaseConnection` that I'll assume::
+
+   class DatabaseConnection:
+       # Database interface
+       def cursor (self):
+           "Returns a cursor object and starts a new transaction"
+       def commit (self):
+           "Commits current transaction"
+       def rollback (self):
+           "Rolls back current transaction"
+
+The :meth:`__enter__` method is pretty easy, having only to start a new
+transaction.  For this application the resulting cursor object would be a useful
+result, so the method will return it.  The user can then add ``as cursor`` to
+their ':keyword:`with`' statement to bind the cursor to a variable name. ::
+
+   class DatabaseConnection:
+       ...
+       def __enter__ (self):
+           # Code to start a new transaction
+           cursor = self.cursor()
+           return cursor
+
+The :meth:`__exit__` method is the most complicated because it's where most of
+the work has to be done.  The method has to check if an exception occurred.  If
+there was no exception, the transaction is committed.  The transaction is rolled
+back if there was an exception.
+
+In the code below, execution will just fall off the end of the function,
+returning the default value of ``None``.  ``None`` is false, so the exception
+will be re-raised automatically.  If you wished, you could be more explicit and
+add a :keyword:`return` statement at the marked location. ::
+
+   class DatabaseConnection:
+       ...
+       def __exit__ (self, type, value, tb):
+           if tb is None:
+               # No exception, so commit
+               self.commit()
+           else:
+               # Exception occurred, so rollback.
+               self.rollback()
+               # return False
+
+
+.. _module-contextlib:
+
+The contextlib module
+---------------------
+
+The new :mod:`contextlib` module provides some functions and a decorator that
+are useful for writing objects for use with the ':keyword:`with`' statement.
+
+The decorator is called :func:`contextmanager`, and lets you write a single
+generator function instead of defining a new class.  The generator should yield
+exactly one value.  The code up to the :keyword:`yield` will be executed as the
+:meth:`__enter__` method, and the value yielded will be the method's return
+value that will get bound to the variable in the ':keyword:`with`' statement's
+:keyword:`as` clause, if any.  The code after the :keyword:`yield` will be
+executed in the :meth:`__exit__` method.  Any exception raised in the block will
+be raised by the :keyword:`yield` statement.
+
+Our database example from the previous section could be written  using this
+decorator as::
+
+   from contextlib import contextmanager
+
+   @contextmanager
+   def db_transaction (connection):
+       cursor = connection.cursor()
+       try:
+           yield cursor
+       except:
+           connection.rollback()
+           raise
+       else:
+           connection.commit()
+
+   db = DatabaseConnection()
+   with db_transaction(db) as cursor:
+       ...
+
+The :mod:`contextlib` module also has a :func:`nested(mgr1, mgr2, ...)` function
+that combines a number of context managers so you don't need to write nested
+':keyword:`with`' statements.  In this example, the single ':keyword:`with`'
+statement both starts a database transaction and acquires a thread lock::
+
+   lock = threading.Lock()
+   with nested (db_transaction(db), lock) as (cursor, locked):
+       ...
+
+Finally, the :func:`closing(object)` function returns *object* so that it can be
+bound to a variable, and calls ``object.close`` at the end of the block. ::
+
+   import urllib, sys
+   from contextlib import closing
+
+   with closing(urllib.urlopen('http://www.yahoo.com')) as f:
+       for line in f:
+           sys.stdout.write(line)
+
+
+.. seealso::
+
+   :pep:`343` - The "with" statement
+      PEP written by Guido van Rossum and Nick Coghlan; implemented by Mike Bland,
+      Guido van Rossum, and Neal Norwitz.  The PEP shows the code generated for a
+      ':keyword:`with`' statement, which can be helpful in learning how the statement
+      works.
+
+   The documentation  for the :mod:`contextlib` module.
+
+.. % ======================================================================
+
+
+.. _pep-352:
+
+PEP 352: Exceptions as New-Style Classes
+========================================
+
+Exception classes can now be new-style classes, not just classic classes, and
+the built-in :exc:`Exception` class and all the standard built-in exceptions
+(:exc:`NameError`, :exc:`ValueError`, etc.) are now new-style classes.
+
+The inheritance hierarchy for exceptions has been rearranged a bit. In 2.5, the
+inheritance relationships are::
+
+   BaseException       # New in Python 2.5
+   |- KeyboardInterrupt
+   |- SystemExit
+   |- Exception
+      |- (all other current built-in exceptions)
+
+This rearrangement was done because people often want to catch all exceptions
+that indicate program errors.  :exc:`KeyboardInterrupt` and :exc:`SystemExit`
+aren't errors, though, and usually represent an explicit action such as the user
+hitting Control-C or code calling :func:`sys.exit`.  A bare ``except:`` will
+catch all exceptions, so you commonly need to list :exc:`KeyboardInterrupt` and
+:exc:`SystemExit` in order to re-raise them.  The usual pattern is::
+
+   try:
+       ...
+   except (KeyboardInterrupt, SystemExit):
+       raise
+   except: 
+       # Log error...  
+       # Continue running program...
+
+In Python 2.5, you can now write ``except Exception`` to achieve the same
+result, catching all the exceptions that usually indicate errors  but leaving
+:exc:`KeyboardInterrupt` and :exc:`SystemExit` alone.  As in previous versions,
+a bare ``except:`` still catches all exceptions.
+
+The goal for Python 3.0 is to require any class raised as an exception to derive
+from :exc:`BaseException` or some descendant of :exc:`BaseException`, and future
+releases in the Python 2.x series may begin to enforce this constraint.
+Therefore, I suggest you begin making all your exception classes derive from
+:exc:`Exception` now.  It's been suggested that the bare ``except:`` form should
+be removed in Python 3.0, but Guido van Rossum hasn't decided whether to do this
+or not.
+
+Raising of strings as exceptions, as in the statement ``raise "Error
+occurred"``, is deprecated in Python 2.5 and will trigger a warning.  The aim is
+to be able to remove the string-exception feature in a few releases.
+
+
+.. seealso::
+
+   :pep:`352` - Required Superclass for Exceptions
+      PEP written by  Brett Cannon and Guido van Rossum; implemented by Brett Cannon.
+
+.. % ======================================================================
+
+
+.. _pep-353:
+
+PEP 353: Using ssize_t as the index type
+========================================
+
+A wide-ranging change to Python's C API, using a new  :ctype:`Py_ssize_t` type
+definition instead of :ctype:`int`,  will permit the interpreter to handle more
+data on 64-bit platforms. This change doesn't affect Python's capacity on 32-bit
+platforms.
+
+Various pieces of the Python interpreter used C's :ctype:`int` type to store
+sizes or counts; for example, the number of items in a list or tuple were stored
+in an :ctype:`int`.  The C compilers for most 64-bit platforms still define
+:ctype:`int` as a 32-bit type, so that meant that lists could only hold up to
+``2**31 - 1`` = 2147483647 items. (There are actually a few different
+programming models that 64-bit C compilers can use -- see
+http://www.unix.org/version2/whatsnew/lp64_wp.html for a discussion -- but the
+most commonly available model leaves :ctype:`int` as 32 bits.)
+
+A limit of 2147483647 items doesn't really matter on a 32-bit platform because
+you'll run out of memory before hitting the length limit. Each list item
+requires space for a pointer, which is 4 bytes, plus space for a
+:ctype:`PyObject` representing the item.  2147483647\*4 is already more bytes
+than a 32-bit address space can contain.
+
+It's possible to address that much memory on a 64-bit platform, however.  The
+pointers for a list that size would only require 16 GiB of space, so it's not
+unreasonable that Python programmers might construct lists that large.
+Therefore, the Python interpreter had to be changed to use some type other than
+:ctype:`int`, and this will be a 64-bit type on 64-bit platforms.  The change
+will cause incompatibilities on 64-bit machines, so it was deemed worth making
+the transition now, while the number of 64-bit users is still relatively small.
+(In 5 or 10 years, we may *all* be on 64-bit machines, and the transition would
+be more painful then.)
+
+This change most strongly affects authors of C extension modules.   Python
+strings and container types such as lists and tuples  now use
+:ctype:`Py_ssize_t` to store their size.   Functions such as
+:cfunc:`PyList_Size`  now return :ctype:`Py_ssize_t`.  Code in extension modules
+may therefore need to have some variables changed to :ctype:`Py_ssize_t`.
+
+The :cfunc:`PyArg_ParseTuple` and :cfunc:`Py_BuildValue` functions have a new
+conversion code, ``n``, for :ctype:`Py_ssize_t`.   :cfunc:`PyArg_ParseTuple`'s
+``s#`` and ``t#`` still output :ctype:`int` by default, but you can define the
+macro  :cmacro:`PY_SSIZE_T_CLEAN` before including :file:`Python.h`  to make
+them return :ctype:`Py_ssize_t`.
+
+:pep:`353` has a section on conversion guidelines that  extension authors should
+read to learn about supporting 64-bit platforms.
+
+
+.. seealso::
+
+   :pep:`353` - Using ssize_t as the index type
+      PEP written and implemented by Martin von Löwis.
+
+.. % ======================================================================
+
+
+.. _pep-357:
+
+PEP 357: The '__index__' method
+===============================
+
+The NumPy developers had a problem that could only be solved by adding a new
+special method, :meth:`__index__`.  When using slice notation, as in
+``[start:stop:step]``, the values of the *start*, *stop*, and *step* indexes
+must all be either integers or long integers.  NumPy defines a variety of
+specialized integer types corresponding to unsigned and signed integers of 8,
+16, 32, and 64 bits, but there was no way to signal that these types could be
+used as slice indexes.
+
+Slicing can't just use the existing :meth:`__int__` method because that method
+is also used to implement coercion to integers.  If slicing used
+:meth:`__int__`, floating-point numbers would also become legal slice indexes
+and that's clearly an undesirable behaviour.
+
+Instead, a new special method called :meth:`__index__` was added.  It takes no
+arguments and returns an integer giving the slice index to use.  For example::
+
+   class C:
+       def __index__ (self):
+           return self.value  
+
+The return value must be either a Python integer or long integer. The
+interpreter will check that the type returned is correct, and raises a
+:exc:`TypeError` if this requirement isn't met.
+
+A corresponding :attr:`nb_index` slot was added to the C-level
+:ctype:`PyNumberMethods` structure to let C extensions implement this protocol.
+:cfunc:`PyNumber_Index(obj)` can be used in extension code to call the
+:meth:`__index__` function and retrieve its result.
+
+
+.. seealso::
+
+   :pep:`357` - Allowing Any Object to be Used for Slicing
+      PEP written  and implemented by Travis Oliphant.
+
+.. % ======================================================================
+
+
+.. _other-lang:
+
+Other Language Changes
+======================
+
+Here are all of the changes that Python 2.5 makes to the core Python language.
+
+* The :class:`dict` type has a new hook for letting subclasses provide a default
+  value when a key isn't contained in the dictionary. When a key isn't found, the
+  dictionary's :meth:`__missing__(key)` method will be called.  This hook is used
+  to implement the new :class:`defaultdict` class in the :mod:`collections`
+  module.  The following example defines a dictionary  that returns zero for any
+  missing key::
+
+     class zerodict (dict):
+         def __missing__ (self, key):
+             return 0
+
+     d = zerodict({1:1, 2:2})
+     print d[1], d[2]   # Prints 1, 2
+     print d[3], d[4]   # Prints 0, 0
+
+* Both 8-bit and Unicode strings have new :meth:`partition(sep)`  and
+  :meth:`rpartition(sep)` methods that simplify a common use case.
+
+  The :meth:`find(S)` method is often used to get an index which is then used to
+  slice the string and obtain the pieces that are before and after the separator.
+  :meth:`partition(sep)` condenses this pattern into a single method call that
+  returns a 3-tuple containing the substring before the separator, the separator
+  itself, and the substring after the separator.  If the separator isn't found,
+  the first element of the tuple is the entire string and the other two elements
+  are empty.  :meth:`rpartition(sep)` also returns a 3-tuple but starts searching
+  from the end of the string; the ``r`` stands for 'reverse'.
+
+  Some examples::
+
+     >>> ('http://www.python.org').partition('://')
+     ('http', '://', 'www.python.org')
+     >>> ('file:/usr/share/doc/index.html').partition('://')
+     ('file:/usr/share/doc/index.html', '', '')
+     >>> (u'Subject: a quick question').partition(':')
+     (u'Subject', u':', u' a quick question')
+     >>> 'www.python.org'.rpartition('.')
+     ('www.python', '.', 'org')
+     >>> 'www.python.org'.rpartition(':')
+     ('', '', 'www.python.org')
+
+  (Implemented by Fredrik Lundh following a suggestion by Raymond Hettinger.)
+
+* The :meth:`startswith` and :meth:`endswith` methods of string types now accept
+  tuples of strings to check for. ::
+
+     def is_image_file (filename):
+         return filename.endswith(('.gif', '.jpg', '.tiff'))
+
+  (Implemented by Georg Brandl following a suggestion by Tom Lynn.)
+
+  .. % RFE #1491485
+
+* The :func:`min` and :func:`max` built-in functions gained a ``key`` keyword
+  parameter analogous to the ``key`` argument for :meth:`sort`.  This parameter
+  supplies a function that takes a single argument and is called for every value
+  in the list; :func:`min`/:func:`max` will return the element with the
+  smallest/largest return value from this function. For example, to find the
+  longest string in a list, you can do::
+
+     L = ['medium', 'longest', 'short']
+     # Prints 'longest'
+     print max(L, key=len)              
+     # Prints 'short', because lexicographically 'short' has the largest value
+     print max(L)         
+
+  (Contributed by Steven Bethard and Raymond Hettinger.)
+
+* Two new built-in functions, :func:`any` and :func:`all`, evaluate whether an
+  iterator contains any true or false values.  :func:`any` returns :const:`True`
+  if any value returned by the iterator is true; otherwise it will return
+  :const:`False`.  :func:`all` returns :const:`True` only if all of the values
+  returned by the iterator evaluate as true. (Suggested by Guido van Rossum, and
+  implemented by Raymond Hettinger.)
+
+* The result of a class's :meth:`__hash__` method can now be either a long
+  integer or a regular integer.  If a long integer is returned, the hash of that
+  value is taken.  In earlier versions the hash value was required to be a
+  regular integer, but in 2.5 the :func:`id` built-in was changed to always
+  return non-negative numbers, and users often seem to use ``id(self)`` in
+  :meth:`__hash__` methods (though this is discouraged).
+
+  .. % Bug #1536021
+
+* ASCII is now the default encoding for modules.  It's now  a syntax error if a
+  module contains string literals with 8-bit characters but doesn't have an
+  encoding declaration.  In Python 2.4 this triggered a warning, not a syntax
+  error.  See :pep:`263`  for how to declare a module's encoding; for example, you
+  might add  a line like this near the top of the source file::
+
+     # -*- coding: latin1 -*-
+
+* A new warning, :class:`UnicodeWarning`, is triggered when  you attempt to
+  compare a Unicode string and an 8-bit string  that can't be converted to Unicode
+  using the default ASCII encoding.   The result of the comparison is false::
+
+     >>> chr(128) == unichr(128)   # Can't convert chr(128) to Unicode
+     __main__:1: UnicodeWarning: Unicode equal comparison failed 
+       to convert both arguments to Unicode - interpreting them 
+       as being unequal
+     False
+     >>> chr(127) == unichr(127)   # chr(127) can be converted
+     True
+
+  Previously this would raise a :class:`UnicodeDecodeError` exception, but in 2.5
+  this could result in puzzling problems when accessing a dictionary.  If you
+  looked up ``unichr(128)`` and ``chr(128)`` was being used as a key, you'd get a
+  :class:`UnicodeDecodeError` exception.  Other changes in 2.5 resulted in this
+  exception being raised instead of suppressed by the code in :file:`dictobject.c`
+  that implements dictionaries.
+
+  Raising an exception for such a comparison is strictly correct, but the change
+  might have broken code, so instead  :class:`UnicodeWarning` was introduced.
+
+  (Implemented by Marc-André Lemburg.)
+
+* One error that Python programmers sometimes make is forgetting to include an
+  :file:`__init__.py` module in a package directory. Debugging this mistake can be
+  confusing, and usually requires running Python with the :option:`-v` switch to
+  log all the paths searched. In Python 2.5, a new :exc:`ImportWarning` warning is
+  triggered when an import would have picked up a directory as a package but no
+  :file:`__init__.py` was found.  This warning is silently ignored by default;
+  provide the :option:`-Wd` option when running the Python executable to display
+  the warning message. (Implemented by Thomas Wouters.)
+
+* The list of base classes in a class definition can now be empty.   As an
+  example, this is now legal::
+
+     class C():
+         pass
+
+  (Implemented by Brett Cannon.)
+
+.. % ======================================================================
+
+
+.. _interactive:
+
+Interactive Interpreter Changes
+-------------------------------
+
+In the interactive interpreter, ``quit`` and ``exit``  have long been strings so
+that new users get a somewhat helpful message when they try to quit::
+
+   >>> quit
+   'Use Ctrl-D (i.e. EOF) to exit.'
+
+In Python 2.5, ``quit`` and ``exit`` are now objects that still produce string
+representations of themselves, but are also callable. Newbies who try ``quit()``
+or ``exit()`` will now exit the interpreter as they expect.  (Implemented by
+Georg Brandl.)
+
+The Python executable now accepts the standard long options  :option:`--help`
+and :option:`--version`; on Windows,  it also accepts the :option:`/?` option
+for displaying a help message. (Implemented by Georg Brandl.)
+
+.. % ======================================================================
+
+
+.. _opts:
+
+Optimizations
+-------------
+
+Several of the optimizations were developed at the NeedForSpeed sprint, an event
+held in Reykjavik, Iceland, from May 21--28 2006. The sprint focused on speed
+enhancements to the CPython implementation and was funded by EWT LLC with local
+support from CCP Games.  Those optimizations added at this sprint are specially
+marked in the following list.
+
+* When they were introduced  in Python 2.4, the built-in :class:`set` and
+  :class:`frozenset` types were built on top of Python's dictionary type.   In 2.5
+  the internal data structure has been customized for implementing sets, and as a
+  result sets will use a third less memory and are somewhat faster. (Implemented
+  by Raymond Hettinger.)
+
+* The speed of some Unicode operations, such as finding substrings, string
+  splitting, and character map encoding and decoding, has been improved.
+  (Substring search and splitting improvements were added by Fredrik Lundh and
+  Andrew Dalke at the NeedForSpeed sprint. Character maps were improved by Walter
+  Dörwald and Martin von Löwis.)
+
+  .. % Patch 1313939, 1359618
+
+* The :func:`long(str, base)` function is now faster on long digit strings
+  because fewer intermediate results are calculated.  The peak is for strings of
+  around 800--1000 digits where  the function is 6 times faster. (Contributed by
+  Alan McIntyre and committed at the NeedForSpeed sprint.)
+
+  .. % Patch 1442927
+
+* It's now illegal to mix iterating over a file  with ``for line in file`` and
+  calling  the file object's :meth:`read`/:meth:`readline`/:meth:`readlines`
+  methods.  Iteration uses an internal buffer and the  :meth:`read\*` methods
+  don't use that buffer.   Instead they would return the data following the
+  buffer, causing the data to appear out of order.  Mixing iteration and these
+  methods will now trigger a :exc:`ValueError` from the :meth:`read\*` method.
+  (Implemented by Thomas Wouters.)
+
+  .. % Patch 1397960
+
+* The :mod:`struct` module now compiles structure format  strings into an
+  internal representation and caches this representation, yielding a 20% speedup.
+  (Contributed by Bob Ippolito at the NeedForSpeed sprint.)
+
+* The :mod:`re` module got a 1 or 2% speedup by switching to  Python's allocator
+  functions instead of the system's  :cfunc:`malloc` and :cfunc:`free`.
+  (Contributed by Jack Diederich at the NeedForSpeed sprint.)
+
+* The code generator's peephole optimizer now performs simple constant folding
+  in expressions.  If you write something like ``a = 2+3``, the code generator
+  will do the arithmetic and produce code corresponding to ``a = 5``.  (Proposed
+  and implemented  by Raymond Hettinger.)
+
+* Function calls are now faster because code objects now keep  the most recently
+  finished frame (a "zombie frame") in an internal field of the code object,
+  reusing it the next time the code object is invoked.  (Original patch by Michael
+  Hudson, modified by Armin Rigo and Richard Jones; committed at the NeedForSpeed
+  sprint.)  Frame objects are also slightly smaller, which may improve cache
+  locality and reduce memory usage a bit.  (Contributed by Neal Norwitz.)
+
+  .. % Patch 876206
+  .. % Patch 1337051
+
+* Python's built-in exceptions are now new-style classes, a change that speeds
+  up instantiation considerably.  Exception handling in Python 2.5 is therefore
+  about 30% faster than in 2.4. (Contributed by Richard Jones, Georg Brandl and
+  Sean Reifschneider at the NeedForSpeed sprint.)
+
+* Importing now caches the paths tried, recording whether  they exist or not so
+  that the interpreter makes fewer  :cfunc:`open` and :cfunc:`stat` calls on
+  startup. (Contributed by Martin von Löwis and Georg Brandl.)
+
+  .. % Patch 921466
+
+.. % ======================================================================
+
+
+.. _modules:
+
+New, Improved, and Removed Modules
+==================================
+
+The standard library received many enhancements and bug fixes in Python 2.5.
+Here's a partial list of the most notable changes, sorted alphabetically by
+module name. Consult the :file:`Misc/NEWS` file in the source tree for a more
+complete list of changes, or look through the SVN logs for all the details.
+
+* The :mod:`audioop` module now supports the a-LAW encoding, and the code for
+  u-LAW encoding has been improved.  (Contributed by Lars Immisch.)
+
+* The :mod:`codecs` module gained support for incremental codecs.  The
+  :func:`codec.lookup` function now returns a :class:`CodecInfo` instance instead
+  of a tuple. :class:`CodecInfo` instances behave like a 4-tuple to preserve
+  backward compatibility but also have the attributes :attr:`encode`,
+  :attr:`decode`, :attr:`incrementalencoder`, :attr:`incrementaldecoder`,
+  :attr:`streamwriter`, and :attr:`streamreader`.  Incremental codecs  can receive
+  input and produce output in multiple chunks; the output is the same as if the
+  entire input was fed to the non-incremental codec. See the :mod:`codecs` module
+  documentation for details. (Designed and implemented by Walter Dörwald.)
+
+  .. % Patch  1436130
+
+* The :mod:`collections` module gained a new type, :class:`defaultdict`, that
+  subclasses the standard :class:`dict` type.  The new type mostly behaves like a
+  dictionary but constructs a default value when a key isn't present,
+  automatically adding it to the dictionary for the requested key value.
+
+  The first argument to :class:`defaultdict`'s constructor is a factory function
+  that gets called whenever a key is requested but not found. This factory
+  function receives no arguments, so you can use built-in type constructors such
+  as :func:`list` or :func:`int`.  For example,  you can make an index of words
+  based on their initial letter like this::
+
+     words = """Nel mezzo del cammin di nostra vita
+     mi ritrovai per una selva oscura
+     che la diritta via era smarrita""".lower().split()
+
+     index = defaultdict(list)
+
+     for w in words:
+         init_letter = w[0]
+         index[init_letter].append(w)
+
+  Printing ``index`` results in the following output::
+
+     defaultdict(<type 'list'>, {'c': ['cammin', 'che'], 'e': ['era'], 
+             'd': ['del', 'di', 'diritta'], 'm': ['mezzo', 'mi'], 
+             'l': ['la'], 'o': ['oscura'], 'n': ['nel', 'nostra'], 
+             'p': ['per'], 's': ['selva', 'smarrita'], 
+             'r': ['ritrovai'], 'u': ['una'], 'v': ['vita', 'via']}
+
+  (Contributed by Guido van Rossum.)
+
+* The :class:`deque` double-ended queue type supplied by the :mod:`collections`
+  module now has a :meth:`remove(value)` method that removes the first occurrence
+  of *value* in the queue, raising :exc:`ValueError` if the value isn't found.
+  (Contributed by Raymond Hettinger.)
+
+* New module: The :mod:`contextlib` module contains helper functions for use
+  with the new ':keyword:`with`' statement.  See section :ref:`module-contextlib`
+  for more about this module.
+
+* New module: The :mod:`cProfile` module is a C implementation of  the existing
+  :mod:`profile` module that has much lower overhead. The module's interface is
+  the same as :mod:`profile`: you run ``cProfile.run('main()')`` to profile a
+  function, can save profile data to a file, etc.  It's not yet known if the
+  Hotshot profiler, which is also written in C but doesn't match the
+  :mod:`profile` module's interface, will continue to be maintained in future
+  versions of Python.  (Contributed by Armin Rigo.)
+
+  Also, the :mod:`pstats` module for analyzing the data measured by the profiler
+  now supports directing the output to any file object by supplying a *stream*
+  argument to the :class:`Stats` constructor. (Contributed by Skip Montanaro.)
+
+* The :mod:`csv` module, which parses files in comma-separated value format,
+  received several enhancements and a number of bugfixes.  You can now set the
+  maximum size in bytes of a field by calling the
+  :meth:`csv.field_size_limit(new_limit)` function; omitting the *new_limit*
+  argument will return the currently-set limit.  The :class:`reader` class now has
+  a :attr:`line_num` attribute that counts the number of physical lines read from
+  the source; records can span multiple physical lines, so :attr:`line_num` is not
+  the same as the number of records read.
+
+  The CSV parser is now stricter about multi-line quoted fields. Previously, if a
+  line ended within a quoted field without a terminating newline character, a
+  newline would be inserted into the returned field. This behavior caused problems
+  when reading files that contained carriage return characters within fields, so
+  the code was changed to return the field without inserting newlines. As a
+  consequence, if newlines embedded within fields are important, the input should
+  be split into lines in a manner that preserves the newline characters.
+
+  (Contributed by Skip Montanaro and Andrew McNamara.)
+
+* The :class:`datetime` class in the :mod:`datetime`  module now has a
+  :meth:`strptime(string, format)`  method for parsing date strings, contributed
+  by Josh Spoerri. It uses the same format characters as :func:`time.strptime` and
+  :func:`time.strftime`::
+
+     from datetime import datetime
+
+     ts = datetime.strptime('10:13:15 2006-03-07',
+                            '%H:%M:%S %Y-%m-%d')
+
+* The :meth:`SequenceMatcher.get_matching_blocks` method in the :mod:`difflib`
+  module now guarantees to return a minimal list of blocks describing matching
+  subsequences.  Previously, the algorithm would occasionally break a block of
+  matching elements into two list entries. (Enhancement by Tim Peters.)
+
+* The :mod:`doctest` module gained a ``SKIP`` option that keeps an example from
+  being executed at all.  This is intended for code snippets that are usage
+  examples intended for the reader and aren't actually test cases.
+
+  An *encoding* parameter was added to the :func:`testfile` function and the
+  :class:`DocFileSuite` class to specify the file's encoding.  This makes it
+  easier to use non-ASCII characters in  tests contained within a docstring.
+  (Contributed by Bjorn Tillenius.)
+
+  .. % Patch 1080727
+
+* The :mod:`email` package has been updated to version 4.0. (Contributed by
+  Barry Warsaw.)
+
+  .. % XXX need to provide some more detail here
+
+* The :mod:`fileinput` module was made more flexible. Unicode filenames are now
+  supported, and a *mode* parameter that defaults to ``"r"`` was added to the
+  :func:`input` function to allow opening files in binary or universal-newline
+  mode.  Another new parameter, *openhook*, lets you use a function other than
+  :func:`open`  to open the input files.  Once you're iterating over  the set of
+  files, the :class:`FileInput` object's new :meth:`fileno` returns the file
+  descriptor for the currently opened file. (Contributed by Georg Brandl.)
+
+* In the :mod:`gc` module, the new :func:`get_count` function returns a 3-tuple
+  containing the current collection counts for the three GC generations.  This is
+  accounting information for the garbage collector; when these counts reach a
+  specified threshold, a garbage collection sweep will be made.  The existing
+  :func:`gc.collect` function now takes an optional *generation* argument of 0, 1,
+  or 2 to specify which generation to collect. (Contributed by Barry Warsaw.)
+
+* The :func:`nsmallest` and  :func:`nlargest` functions in the :mod:`heapq`
+  module  now support a ``key`` keyword parameter similar to the one provided by
+  the :func:`min`/:func:`max` functions and the :meth:`sort` methods.  For
+  example::
+
+     >>> import heapq
+     >>> L = ["short", 'medium', 'longest', 'longer still']
+     >>> heapq.nsmallest(2, L)  # Return two lowest elements, lexicographically
+     ['longer still', 'longest']
+     >>> heapq.nsmallest(2, L, key=len)   # Return two shortest elements
+     ['short', 'medium']
+
+  (Contributed by Raymond Hettinger.)
+
+* The :func:`itertools.islice` function now accepts ``None`` for the start and
+  step arguments.  This makes it more compatible with the attributes of slice
+  objects, so that you can now write the following::
+
+     s = slice(5)     # Create slice object
+     itertools.islice(iterable, s.start, s.stop, s.step)
+
+  (Contributed by Raymond Hettinger.)
+
+* The :func:`format` function in the :mod:`locale` module has been modified and
+  two new functions were added, :func:`format_string` and :func:`currency`.
+
+  The :func:`format` function's *val* parameter could previously be a string as
+  long as no more than one %char specifier appeared; now the parameter must be
+  exactly one %char specifier with no surrounding text.  An optional *monetary*
+  parameter was also added which, if ``True``, will use the locale's rules for
+  formatting currency in placing a separator between groups of three digits.
+
+  To format strings with multiple %char specifiers, use the new
+  :func:`format_string` function that works like :func:`format` but also supports
+  mixing %char specifiers with arbitrary text.
+
+  A new :func:`currency` function was also added that formats a number according
+  to the current locale's settings.
+
+  (Contributed by Georg Brandl.)
+
+  .. % Patch 1180296
+
+* The :mod:`mailbox` module underwent a massive rewrite to add the capability to
+  modify mailboxes in addition to reading them.  A new set of classes that include
+  :class:`mbox`, :class:`MH`, and :class:`Maildir` are used to read mailboxes, and
+  have an :meth:`add(message)` method to add messages, :meth:`remove(key)` to
+  remove messages, and :meth:`lock`/:meth:`unlock` to lock/unlock the mailbox.
+  The following example converts a maildir-format mailbox into an mbox-format
+  one::
+
+     import mailbox
+
+     # 'factory=None' uses email.Message.Message as the class representing
+     # individual messages.
+     src = mailbox.Maildir('maildir', factory=None)
+     dest = mailbox.mbox('/tmp/mbox')
+
+     for msg in src:
+         dest.add(msg)
+
+  (Contributed by Gregory K. Johnson.  Funding was provided by Google's 2005
+  Summer of Code.)
+
+* New module: the :mod:`msilib` module allows creating Microsoft Installer
+  :file:`.msi` files and CAB files.  Some support for reading the :file:`.msi`
+  database is also included. (Contributed by Martin von Löwis.)
+
+* The :mod:`nis` module now supports accessing domains other than the system
+  default domain by supplying a *domain* argument to the :func:`nis.match` and
+  :func:`nis.maps` functions. (Contributed by Ben Bell.)
+
+* The :mod:`operator` module's :func:`itemgetter`  and :func:`attrgetter`
+  functions now support multiple fields.   A call such as
+  ``operator.attrgetter('a', 'b')`` will return a function  that retrieves the
+  :attr:`a` and :attr:`b` attributes.  Combining  this new feature with the
+  :meth:`sort` method's ``key`` parameter  lets you easily sort lists using
+  multiple fields. (Contributed by Raymond Hettinger.)
+
+* The :mod:`optparse` module was updated to version 1.5.1 of the Optik library.
+  The :class:`OptionParser` class gained an :attr:`epilog` attribute, a string
+  that will be printed after the help message, and a :meth:`destroy` method to
+  break reference cycles created by the object. (Contributed by Greg Ward.)
+
+* The :mod:`os` module underwent several changes.  The :attr:`stat_float_times`
+  variable now defaults to true, meaning that :func:`os.stat` will now return time
+  values as floats.  (This doesn't necessarily mean that :func:`os.stat` will
+  return times that are precise to fractions of a second; not all systems support
+  such precision.)
+
+  Constants named :attr:`os.SEEK_SET`, :attr:`os.SEEK_CUR`, and
+  :attr:`os.SEEK_END` have been added; these are the parameters to the
+  :func:`os.lseek` function.  Two new constants for locking are
+  :attr:`os.O_SHLOCK` and :attr:`os.O_EXLOCK`.
+
+  Two new functions, :func:`wait3` and :func:`wait4`, were added.  They're similar
+  the :func:`waitpid` function which waits for a child process to exit and returns
+  a tuple of the process ID and its exit status, but :func:`wait3` and
+  :func:`wait4` return additional information.  :func:`wait3` doesn't take a
+  process ID as input, so it waits for any child process to exit and returns a
+  3-tuple of *process-id*, *exit-status*, *resource-usage* as returned from the
+  :func:`resource.getrusage` function. :func:`wait4(pid)` does take a process ID.
+  (Contributed by Chad J. Schroeder.)
+
+  On FreeBSD, the :func:`os.stat` function now returns  times with nanosecond
+  resolution, and the returned object now has :attr:`st_gen` and
+  :attr:`st_birthtime`. The :attr:`st_flags` member is also available, if the
+  platform supports it. (Contributed by Antti Louko and  Diego Pettenò.)
+
+  .. % (Patch 1180695, 1212117)
+
+* The Python debugger provided by the :mod:`pdb` module can now store lists of
+  commands to execute when a breakpoint is reached and execution stops.  Once
+  breakpoint #1 has been created, enter ``commands 1`` and enter a series of
+  commands to be executed, finishing the list with ``end``.  The command list can
+  include commands that resume execution, such as ``continue`` or ``next``.
+  (Contributed by Grégoire Dooms.)
+
+  .. % Patch 790710
+
+* The :mod:`pickle` and :mod:`cPickle` modules no longer accept a return value
+  of ``None`` from the :meth:`__reduce__` method; the method must return a tuple
+  of arguments instead.  The ability to return ``None`` was deprecated in Python
+  2.4, so this completes the removal of the feature.
+
+* The :mod:`pkgutil` module, containing various utility functions for finding
+  packages, was enhanced to support PEP 302's import hooks and now also works for
+  packages stored in ZIP-format archives. (Contributed by Phillip J. Eby.)
+
+* The pybench benchmark suite by Marc-André Lemburg is now included in the
+  :file:`Tools/pybench` directory.  The pybench suite is an improvement on the
+  commonly used :file:`pystone.py` program because pybench provides a more
+  detailed measurement of the interpreter's speed.  It times particular operations
+  such as function calls, tuple slicing, method lookups, and numeric operations,
+  instead of performing many different operations and reducing the result to a
+  single number as :file:`pystone.py` does.
+
+* The :mod:`pyexpat` module now uses version 2.0 of the Expat parser.
+  (Contributed by Trent Mick.)
+
+* The :class:`Queue` class provided by the :mod:`Queue` module gained two new
+  methods.  :meth:`join` blocks until all items in the queue have been retrieved
+  and all processing work on the items  have been completed.  Worker threads call
+  the other new method,  :meth:`task_done`, to signal that processing for an item
+  has been completed.  (Contributed by Raymond Hettinger.)
+
+* The old :mod:`regex` and :mod:`regsub` modules, which have been  deprecated
+  ever since Python 2.0, have finally been deleted.   Other deleted modules:
+  :mod:`statcache`, :mod:`tzparse`, :mod:`whrandom`.
+
+* Also deleted: the :file:`lib-old` directory, which includes ancient modules
+  such as :mod:`dircmp` and :mod:`ni`, was removed.  :file:`lib-old` wasn't on the
+  default ``sys.path``, so unless your programs explicitly added the directory to
+  ``sys.path``, this removal shouldn't affect your code.
+
+* The :mod:`rlcompleter` module is no longer  dependent on importing the
+  :mod:`readline` module and therefore now works on non-Unix platforms. (Patch
+  from Robert Kiendl.)
+
+  .. % Patch #1472854
+
+* The :mod:`SimpleXMLRPCServer` and :mod:`DocXMLRPCServer`  classes now have a
+  :attr:`rpc_paths` attribute that constrains XML-RPC operations to a limited set
+  of URL paths; the default is to allow only ``'/'`` and ``'/RPC2'``.  Setting
+  :attr:`rpc_paths` to ``None`` or an empty tuple disables  this path checking.
+
+  .. % Bug #1473048
+
+* The :mod:`socket` module now supports :const:`AF_NETLINK` sockets on Linux,
+  thanks to a patch from Philippe Biondi.   Netlink sockets are a Linux-specific
+  mechanism for communications between a user-space process and kernel code; an
+  introductory  article about them is at http://www.linuxjournal.com/article/7356.
+  In Python code, netlink addresses are represented as a tuple of 2 integers,
+  ``(pid, group_mask)``.
+
+  Two new methods on socket objects, :meth:`recv_into(buffer)` and
+  :meth:`recvfrom_into(buffer)`, store the received data in an object  that
+  supports the buffer protocol instead of returning the data as a string.  This
+  means you can put the data directly into an array or a memory-mapped file.
+
+  Socket objects also gained :meth:`getfamily`, :meth:`gettype`, and
+  :meth:`getproto` accessor methods to retrieve the family, type, and protocol
+  values for the socket.
+
+* New module: the :mod:`spwd` module provides functions for accessing the shadow
+  password database on systems that support  shadow passwords.
+
+* The :mod:`struct` is now faster because it  compiles format strings into
+  :class:`Struct` objects with :meth:`pack` and :meth:`unpack` methods.  This is
+  similar to how the :mod:`re` module lets you create compiled regular expression
+  objects.  You can still use the module-level  :func:`pack` and :func:`unpack`
+  functions; they'll create  :class:`Struct` objects and cache them.  Or you can
+  use  :class:`Struct` instances directly::
+
+     s = struct.Struct('ih3s')
+
+     data = s.pack(1972, 187, 'abc')
+     year, number, name = s.unpack(data)
+
+  You can also pack and unpack data to and from buffer objects directly using the
+  :meth:`pack_into(buffer, offset, v1, v2, ...)` and :meth:`unpack_from(buffer,
+  offset)` methods.  This lets you store data directly into an array or a memory-
+  mapped file.
+
+  (:class:`Struct` objects were implemented by Bob Ippolito at the NeedForSpeed
+  sprint.  Support for buffer objects was added by Martin Blais, also at the
+  NeedForSpeed sprint.)
+
+* The Python developers switched from CVS to Subversion during the 2.5
+  development process.  Information about the exact build version is available as
+  the ``sys.subversion`` variable, a 3-tuple of ``(interpreter-name, branch-name,
+  revision-range)``.  For example, at the time of writing my copy of 2.5 was
+  reporting ``('CPython', 'trunk', '45313:45315')``.
+
+  This information is also available to C extensions via the
+  :cfunc:`Py_GetBuildInfo` function that returns a  string of build information
+  like this: ``"trunk:45355:45356M, Apr 13 2006, 07:42:19"``.   (Contributed by
+  Barry Warsaw.)
+
+* Another new function, :func:`sys._current_frames`, returns the current stack
+  frames for all running threads as a dictionary mapping thread identifiers to the
+  topmost stack frame currently active in that thread at the time the function is
+  called.  (Contributed by Tim Peters.)
+
+* The :class:`TarFile` class in the :mod:`tarfile` module now has an
+  :meth:`extractall` method that extracts all members from the archive into the
+  current working directory.  It's also possible to set a different directory as
+  the extraction target, and to unpack only a subset of the archive's members.
+
+  The compression used for a tarfile opened in stream mode can now be autodetected
+  using the mode ``'r|*'``. (Contributed by Lars Gustäbel.)
+
+  .. % patch 918101
+
+* The :mod:`threading` module now lets you set the stack size used when new
+  threads are created. The :func:`stack_size([*size*])` function returns the
+  currently configured stack size, and supplying the optional *size* parameter
+  sets a new value.  Not all platforms support changing the stack size, but
+  Windows, POSIX threading, and OS/2 all do. (Contributed by Andrew MacIntyre.)
+
+  .. % Patch 1454481
+
+* The :mod:`unicodedata` module has been updated to use version 4.1.0 of the
+  Unicode character database.  Version 3.2.0 is required  by some specifications,
+  so it's still available as  :attr:`unicodedata.ucd_3_2_0`.
+
+* New module: the  :mod:`uuid` module generates  universally unique identifiers
+  (UUIDs) according to :rfc:`4122`.  The RFC defines several different UUID
+  versions that are generated from a starting string, from system properties, or
+  purely randomly.  This module contains a :class:`UUID` class and  functions
+  named :func:`uuid1`, :func:`uuid3`, :func:`uuid4`,  and  :func:`uuid5` to
+  generate different versions of UUID.  (Version 2 UUIDs  are not specified in
+  :rfc:`4122` and are not supported by this module.) ::
+
+     >>> import uuid
+     >>> # make a UUID based on the host ID and current time
+     >>> uuid.uuid1()
+     UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')
+
+     >>> # make a UUID using an MD5 hash of a namespace UUID and a name
+     >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
+     UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')
+
+     >>> # make a random UUID
+     >>> uuid.uuid4()
+     UUID('16fd2706-8baf-433b-82eb-8c7fada847da')
+
+     >>> # make a UUID using a SHA-1 hash of a namespace UUID and a name
+     >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
+     UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')
+
+  (Contributed by Ka-Ping Yee.)
+
+* The :mod:`weakref` module's :class:`WeakKeyDictionary` and
+  :class:`WeakValueDictionary` types gained new methods for iterating over the
+  weak references contained in the dictionary.  :meth:`iterkeyrefs` and
+  :meth:`keyrefs` methods were added to :class:`WeakKeyDictionary`, and
+  :meth:`itervaluerefs` and :meth:`valuerefs` were added to
+  :class:`WeakValueDictionary`.  (Contributed by Fred L. Drake, Jr.)
+
+* The :mod:`webbrowser` module received a number of enhancements. It's now
+  usable as a script with ``python -m webbrowser``, taking a URL as the argument;
+  there are a number of switches  to control the behaviour (:option:`-n` for a new
+  browser window,  :option:`-t` for a new tab).  New module-level functions,
+  :func:`open_new` and :func:`open_new_tab`, were added  to support this.  The
+  module's :func:`open` function supports an additional feature, an *autoraise*
+  parameter that signals whether to raise the open window when possible. A number
+  of additional browsers were added to the supported list such as Firefox, Opera,
+  Konqueror, and elinks.  (Contributed by Oleg Broytmann and Georg Brandl.)
+
+  .. % Patch #754022
+
+* The :mod:`xmlrpclib` module now supports returning  :class:`datetime` objects
+  for the XML-RPC date type.  Supply  ``use_datetime=True`` to the :func:`loads`
+  function or the :class:`Unmarshaller` class to enable this feature. (Contributed
+  by Skip Montanaro.)
+
+  .. % Patch 1120353
+
+* The :mod:`zipfile` module now supports the ZIP64 version of the  format,
+  meaning that a .zip archive can now be larger than 4 GiB and can contain
+  individual files larger than 4 GiB.  (Contributed by Ronald Oussoren.)
+
+  .. % Patch 1446489
+
+* The :mod:`zlib` module's :class:`Compress` and :class:`Decompress` objects now
+  support a :meth:`copy` method that makes a copy of the  object's internal state
+  and returns a new  :class:`Compress` or :class:`Decompress` object.
+  (Contributed by Chris AtLee.)
+
+  .. % Patch 1435422
+
+.. % ======================================================================
+
+
+.. _module-ctypes:
+
+The ctypes package
+------------------
+
+The :mod:`ctypes` package, written by Thomas Heller, has been added  to the
+standard library.  :mod:`ctypes` lets you call arbitrary functions  in shared
+libraries or DLLs.  Long-time users may remember the :mod:`dl` module, which
+provides functions for loading shared libraries and calling functions in them.
+The :mod:`ctypes` package is much fancier.
+
+To load a shared library or DLL, you must create an instance of the
+:class:`CDLL` class and provide the name or path of the shared library or DLL.
+Once that's done, you can call arbitrary functions by accessing them as
+attributes of the :class:`CDLL` object.   ::
+
+   import ctypes
+
+   libc = ctypes.CDLL('libc.so.6')
+   result = libc.printf("Line of output\n")
+
+Type constructors for the various C types are provided: :func:`c_int`,
+:func:`c_float`, :func:`c_double`, :func:`c_char_p` (equivalent to :ctype:`char
+\*`), and so forth.  Unlike Python's types, the C versions are all mutable; you
+can assign to their :attr:`value` attribute to change the wrapped value.  Python
+integers and strings will be automatically converted to the corresponding C
+types, but for other types you  must call the correct type constructor.  (And I
+mean *must*;  getting it wrong will often result in the interpreter crashing
+with a segmentation fault.)
+
+You shouldn't use :func:`c_char_p` with a Python string when the C function will
+be modifying the memory area, because Python strings are  supposed to be
+immutable; breaking this rule will cause puzzling bugs.  When you need a
+modifiable memory area, use :func:`create_string_buffer`::
+
+   s = "this is a string"
+   buf = ctypes.create_string_buffer(s)
+   libc.strfry(buf)
+
+C functions are assumed to return integers, but you can set the :attr:`restype`
+attribute of the function object to  change this::
+
+   >>> libc.atof('2.71828')
+   -1783957616
+   >>> libc.atof.restype = ctypes.c_double
+   >>> libc.atof('2.71828')
+   2.71828
+
+:mod:`ctypes` also provides a wrapper for Python's C API  as the
+``ctypes.pythonapi`` object.  This object does *not*  release the global
+interpreter lock before calling a function, because the lock must be held when
+calling into the interpreter's code.   There's a :class:`py_object()` type
+constructor that will create a  :ctype:`PyObject \*` pointer.  A simple usage::
+
+   import ctypes
+
+   d = {}
+   ctypes.pythonapi.PyObject_SetItem(ctypes.py_object(d),
+             ctypes.py_object("abc"),  ctypes.py_object(1))
+   # d is now {'abc', 1}.
+
+Don't forget to use :class:`py_object()`; if it's omitted you end  up with a
+segmentation fault.
+
+:mod:`ctypes` has been around for a while, but people still write  and
+distribution hand-coded extension modules because you can't rely on
+:mod:`ctypes` being present. Perhaps developers will begin to write  Python
+wrappers atop a library accessed through :mod:`ctypes` instead of extension
+modules, now that :mod:`ctypes` is included with core Python.
+
+
+.. seealso::
+
+   http://starship.python.net/crew/theller/ctypes/
+      The ctypes web page, with a tutorial, reference, and FAQ.
+
+   The documentation  for the :mod:`ctypes` module.
+
+.. % ======================================================================
+
+
+.. _module-etree:
+
+The ElementTree package
+-----------------------
+
+A subset of Fredrik Lundh's ElementTree library for processing XML has been
+added to the standard library as :mod:`xml.etree`.  The available modules are
+:mod:`ElementTree`, :mod:`ElementPath`, and :mod:`ElementInclude` from
+ElementTree 1.2.6.    The :mod:`cElementTree` accelerator module is also
+included.
+
+The rest of this section will provide a brief overview of using ElementTree.
+Full documentation for ElementTree is available at http://effbot.org/zone
+/element-index.htm.
+
+ElementTree represents an XML document as a tree of element nodes. The text
+content of the document is stored as the :attr:`.text` and :attr:`.tail`
+attributes of  (This is one of the major differences between ElementTree and
+the Document Object Model; in the DOM there are many different types of node,
+including :class:`TextNode`.)
+
+The most commonly used parsing function is :func:`parse`, that takes either a
+string (assumed to contain a filename) or a file-like object and returns an
+:class:`ElementTree` instance::
+
+   from xml.etree import ElementTree as ET
+
+   tree = ET.parse('ex-1.xml')
+
+   feed = urllib.urlopen(
+             'http://planet.python.org/rss10.xml')
+   tree = ET.parse(feed)
+
+Once you have an :class:`ElementTree` instance, you can call its :meth:`getroot`
+method to get the root :class:`Element` node.
+
+There's also an :func:`XML` function that takes a string literal and returns an
+:class:`Element` node (not an :class:`ElementTree`).   This function provides a
+tidy way to incorporate XML fragments, approaching the convenience of an XML
+literal::
+
+   svg = ET.XML("""<svg width="10px" version="1.0">
+                </svg>""")
+   svg.set('height', '320px')
+   svg.append(elem1)
+
+Each XML element supports some dictionary-like and some list-like access
+methods.  Dictionary-like operations are used to access attribute values, and
+list-like operations are used to access child nodes.
+
++-------------------------------+--------------------------------------------+
+| Operation                     | Result                                     |
++===============================+============================================+
+| ``elem[n]``                   | Returns n'th child element.                |
++-------------------------------+--------------------------------------------+
+| ``elem[m:n]``                 | Returns list of m'th through n'th child    |
+|                               | elements.                                  |
++-------------------------------+--------------------------------------------+
+| ``len(elem)``                 | Returns number of child elements.          |
++-------------------------------+--------------------------------------------+
+| ``list(elem)``                | Returns list of child elements.            |
++-------------------------------+--------------------------------------------+
+| ``elem.append(elem2)``        | Adds *elem2* as a child.                   |
++-------------------------------+--------------------------------------------+
+| ``elem.insert(index, elem2)`` | Inserts *elem2* at the specified location. |
++-------------------------------+--------------------------------------------+
+| ``del elem[n]``               | Deletes n'th child element.                |
++-------------------------------+--------------------------------------------+
+| ``elem.keys()``               | Returns list of attribute names.           |
++-------------------------------+--------------------------------------------+
+| ``elem.get(name)``            | Returns value of attribute *name*.         |
++-------------------------------+--------------------------------------------+
+| ``elem.set(name, value)``     | Sets new value for attribute *name*.       |
++-------------------------------+--------------------------------------------+
+| ``elem.attrib``               | Retrieves the dictionary containing        |
+|                               | attributes.                                |
++-------------------------------+--------------------------------------------+
+| ``del elem.attrib[name]``     | Deletes attribute *name*.                  |
++-------------------------------+--------------------------------------------+
+
+Comments and processing instructions are also represented as :class:`Element`
+nodes.  To check if a node is a comment or processing instructions::
+
+   if elem.tag is ET.Comment:
+       ...
+   elif elem.tag is ET.ProcessingInstruction:
+       ...
+
+To generate XML output, you should call the :meth:`ElementTree.write` method.
+Like :func:`parse`, it can take either a string or a file-like object::
+
+   # Encoding is US-ASCII
+   tree.write('output.xml')
+
+   # Encoding is UTF-8
+   f = open('output.xml', 'w')
+   tree.write(f, encoding='utf-8')
+
+(Caution: the default encoding used for output is ASCII.  For general XML work,
+where an element's name may contain arbitrary Unicode characters, ASCII isn't a
+very useful encoding because it will raise an exception if an element's name
+contains any characters with values greater than 127.  Therefore, it's best to
+specify a different encoding such as UTF-8 that can handle any Unicode
+character.)
+
+This section is only a partial description of the ElementTree interfaces. Please
+read the package's official documentation for more details.
+
+
+.. seealso::
+
+   http://effbot.org/zone/element-index.htm
+      Official documentation for ElementTree.
+
+.. % ======================================================================
+
+
+.. _module-hashlib:
+
+The hashlib package
+-------------------
+
+A new :mod:`hashlib` module, written by Gregory P. Smith,  has been added to
+replace the :mod:`md5` and :mod:`sha` modules.  :mod:`hashlib` adds support for
+additional secure hashes (SHA-224, SHA-256, SHA-384, and SHA-512). When
+available, the module uses OpenSSL for fast platform optimized implementations
+of algorithms.
+
+The old :mod:`md5` and :mod:`sha` modules still exist as wrappers around hashlib
+to preserve backwards compatibility.  The new module's interface is very close
+to that of the old modules, but not identical. The most significant difference
+is that the constructor functions for creating new hashing objects are named
+differently. ::
+
+   # Old versions
+   h = md5.md5()   
+   h = md5.new()   
+
+   # New version 
+   h = hashlib.md5()
+
+   # Old versions
+   h = sha.sha()   
+   h = sha.new()   
+
+   # New version 
+   h = hashlib.sha1()
+
+   # Hash that weren't previously available
+   h = hashlib.sha224()
+   h = hashlib.sha256()
+   h = hashlib.sha384()
+   h = hashlib.sha512()
+
+   # Alternative form
+   h = hashlib.new('md5')          # Provide algorithm as a string
+
+Once a hash object has been created, its methods are the same as before:
+:meth:`update(string)` hashes the specified string into the  current digest
+state, :meth:`digest` and :meth:`hexdigest` return the digest value as a binary
+string or a string of hex digits, and :meth:`copy` returns a new hashing object
+with the same digest state.
+
+
+.. seealso::
+
+   The documentation  for the :mod:`hashlib` module.
+
+.. % ======================================================================
+
+
+.. _module-sqlite:
+
+The sqlite3 package
+-------------------
+
+The pysqlite module (http://www.pysqlite.org), a wrapper for the SQLite embedded
+database, has been added to the standard library under the package name
+:mod:`sqlite3`.
+
+SQLite is a C library that provides a lightweight disk-based database that
+doesn't require a separate server process and allows accessing the database
+using a nonstandard variant of the SQL query language. Some applications can use
+SQLite for internal data storage.  It's also possible to prototype an
+application using SQLite and then port the code to a larger database such as
+PostgreSQL or Oracle.
+
+pysqlite was written by Gerhard Häring and provides a SQL interface compliant
+with the DB-API 2.0 specification described by :pep:`249`.
+
+If you're compiling the Python source yourself, note that the source tree
+doesn't include the SQLite code, only the wrapper module. You'll need to have
+the SQLite libraries and headers installed before compiling Python, and the
+build process will compile the module when the necessary headers are available.
+
+To use the module, you must first create a :class:`Connection` object that
+represents the database.  Here the data will be stored in the
+:file:`/tmp/example` file::
+
+   conn = sqlite3.connect('/tmp/example')
+
+You can also supply the special name ``:memory:`` to create a database in RAM.
+
+Once you have a :class:`Connection`, you can create a :class:`Cursor`  object
+and call its :meth:`execute` method to perform SQL commands::
+
+   c = conn.cursor()
+
+   # Create table
+   c.execute('''create table stocks
+   (date text, trans text, symbol text,
+    qty real, price real)''')
+
+   # Insert a row of data
+   c.execute("""insert into stocks
+             values ('2006-01-05','BUY','RHAT',100,35.14)""")
+
+Usually your SQL operations will need to use values from Python variables.  You
+shouldn't assemble your query using Python's string operations because doing so
+is insecure; it makes your program vulnerable to an SQL injection attack.
+
+Instead, use the DB-API's parameter substitution.  Put ``?`` as a placeholder
+wherever you want to use a value, and then provide a tuple of values as the
+second argument to the cursor's :meth:`execute` method.  (Other database modules
+may use a different placeholder, such as ``%s`` or ``:1``.) For example::
+
+   # Never do this -- insecure!
+   symbol = 'IBM'
+   c.execute("... where symbol = '%s'" % symbol)
+
+   # Do this instead
+   t = (symbol,)
+   c.execute('select * from stocks where symbol=?', t)
+
+   # Larger example
+   for t in (('2006-03-28', 'BUY', 'IBM', 1000, 45.00),
+             ('2006-04-05', 'BUY', 'MSOFT', 1000, 72.00),
+             ('2006-04-06', 'SELL', 'IBM', 500, 53.00),
+            ):
+       c.execute('insert into stocks values (?,?,?,?,?)', t)
+
+To retrieve data after executing a SELECT statement, you can either  treat the
+cursor as an iterator, call the cursor's :meth:`fetchone` method to retrieve a
+single matching row,  or call :meth:`fetchall` to get a list of the matching
+rows.
+
+This example uses the iterator form::
+
+   >>> c = conn.cursor()
+   >>> c.execute('select * from stocks order by price')
+   >>> for row in c:
+   ...    print row
+   ...
+   (u'2006-01-05', u'BUY', u'RHAT', 100, 35.140000000000001)
+   (u'2006-03-28', u'BUY', u'IBM', 1000, 45.0)
+   (u'2006-04-06', u'SELL', u'IBM', 500, 53.0)
+   (u'2006-04-05', u'BUY', u'MSOFT', 1000, 72.0)
+   >>>
+
+For more information about the SQL dialect supported by SQLite, see
+http://www.sqlite.org.
+
+
+.. seealso::
+
+   http://www.pysqlite.org
+      The pysqlite web page.
+
+   http://www.sqlite.org
+      The SQLite web page; the documentation describes the syntax and the available
+      data types for the supported SQL dialect.
+
+   The documentation  for the :mod:`sqlite3` module.
+
+   :pep:`249` - Database API Specification 2.0
+      PEP written by Marc-André Lemburg.
+
+.. % ======================================================================
+
+
+.. _module-wsgiref:
+
+The wsgiref package
+-------------------
+
+The Web Server Gateway Interface (WSGI) v1.0 defines a standard interface
+between web servers and Python web applications and is described in :pep:`333`.
+The :mod:`wsgiref` package is a reference implementation of the WSGI
+specification.
+
+.. % XXX should this be in a PEP 333 section instead?
+
+The package includes a basic HTTP server that will run a WSGI application; this
+server is useful for debugging but isn't intended for  production use.  Setting
+up a server takes only a few lines of code::
+
+   from wsgiref import simple_server
+
+   wsgi_app = ...
+
+   host = ''
+   port = 8000
+   httpd = simple_server.make_server(host, port, wsgi_app)
+   httpd.serve_forever()
+
+.. % XXX discuss structure of WSGI applications?
+.. % XXX provide an example using Django or some other framework?
+
+
+.. seealso::
+
+   http://www.wsgi.org
+      A central web site for WSGI-related resources.
+
+   :pep:`333` - Python Web Server Gateway Interface v1.0
+      PEP written by Phillip J. Eby.
+
+.. % ======================================================================
+
+
+.. _build-api:
+
+Build and C API Changes
+=======================
+
+Changes to Python's build process and to the C API include:
+
+* The Python source tree was converted from CVS to Subversion,  in a complex
+  migration procedure that was supervised and flawlessly carried out by Martin von
+  Löwis.  The procedure was developed as :pep:`347`.
+
+* Coverity, a company that markets a source code analysis tool called Prevent,
+  provided the results of their examination of the Python source code.  The
+  analysis found about 60 bugs that  were quickly fixed.  Many of the bugs were
+  refcounting problems, often occurring in error-handling code.  See
+  http://scan.coverity.com for the statistics.
+
+* The largest change to the C API came from :pep:`353`, which modifies the
+  interpreter to use a :ctype:`Py_ssize_t` type definition instead of
+  :ctype:`int`.  See the earlier section :ref:`pep-353` for a discussion of this
+  change.
+
+* The design of the bytecode compiler has changed a great deal,  no longer
+  generating bytecode by traversing the parse tree.  Instead the parse tree is
+  converted to an abstract syntax tree (or AST), and it is  the abstract syntax
+  tree that's traversed to produce the bytecode.
+
+  It's possible for Python code to obtain AST objects by using the
+  :func:`compile` built-in and specifying ``_ast.PyCF_ONLY_AST`` as the value of
+  the  *flags* parameter::
+
+     from _ast import PyCF_ONLY_AST
+     ast = compile("""a=0
+     for i in range(10):
+         a += i
+     """, "<string>", 'exec', PyCF_ONLY_AST)
+
+     assignment = ast.body[0]
+     for_loop = ast.body[1]
+
+  No official documentation has been written for the AST code yet, but :pep:`339`
+  discusses the design.  To start learning about the code, read the definition of
+  the various AST nodes in :file:`Parser/Python.asdl`.  A Python script reads this
+  file and generates a set of C structure definitions in
+  :file:`Include/Python-ast.h`.  The :cfunc:`PyParser_ASTFromString` and
+  :cfunc:`PyParser_ASTFromFile`, defined in :file:`Include/pythonrun.h`, take
+  Python source as input and return the root of an AST representing the contents.
+  This AST can then be turned into a code object by :cfunc:`PyAST_Compile`.  For
+  more information, read the source code, and then ask questions on python-dev.
+
+  The AST code was developed under Jeremy Hylton's management, and implemented by
+  (in alphabetical order) Brett Cannon, Nick Coghlan, Grant Edwards, John
+  Ehresman, Kurt Kaiser, Neal Norwitz, Tim Peters, Armin Rigo, and Neil
+  Schemenauer, plus the participants in a number of AST sprints at conferences
+  such as PyCon.
+
+  .. % List of names taken from Jeremy's python-dev post at
+  .. % http://mail.python.org/pipermail/python-dev/2005-October/057500.html
+
+* Evan Jones's patch to obmalloc, first described in a talk at PyCon DC 2005,
+  was applied.  Python 2.4 allocated small objects in 256K-sized arenas, but never
+  freed arenas.  With this patch, Python will free arenas when they're empty.  The
+  net effect is that on some platforms, when you allocate many objects, Python's
+  memory usage may actually drop when you delete them and the memory may be
+  returned to the operating system.  (Implemented by Evan Jones, and reworked by
+  Tim Peters.)
+
+  Note that this change means extension modules must be more careful when
+  allocating memory.  Python's API has many different functions for allocating
+  memory that are grouped into families.  For example, :cfunc:`PyMem_Malloc`,
+  :cfunc:`PyMem_Realloc`, and :cfunc:`PyMem_Free` are one family that allocates
+  raw memory, while :cfunc:`PyObject_Malloc`, :cfunc:`PyObject_Realloc`, and
+  :cfunc:`PyObject_Free` are another family that's supposed to be used for
+  creating Python objects.
+
+  Previously these different families all reduced to the platform's
+  :cfunc:`malloc` and :cfunc:`free` functions.  This meant  it didn't matter if
+  you got things wrong and allocated memory with the :cfunc:`PyMem` function but
+  freed it with the :cfunc:`PyObject` function.  With 2.5's changes to obmalloc,
+  these families now do different things and mismatches will probably result in a
+  segfault.  You should carefully test your C extension modules with Python 2.5.
+
+* The built-in set types now have an official C API.  Call :cfunc:`PySet_New`
+  and :cfunc:`PyFrozenSet_New` to create a new set, :cfunc:`PySet_Add` and
+  :cfunc:`PySet_Discard` to add and remove elements, and :cfunc:`PySet_Contains`
+  and :cfunc:`PySet_Size` to examine the set's state. (Contributed by Raymond
+  Hettinger.)
+
+* C code can now obtain information about the exact revision of the Python
+  interpreter by calling the  :cfunc:`Py_GetBuildInfo` function that returns a
+  string of build information like this: ``"trunk:45355:45356M, Apr 13 2006,
+  07:42:19"``.   (Contributed by Barry Warsaw.)
+
+* Two new macros can be used to indicate C functions that are local to the
+  current file so that a faster calling convention can be used.
+  :cfunc:`Py_LOCAL(type)` declares the function as returning a value of the
+  specified *type* and uses a fast-calling qualifier.
+  :cfunc:`Py_LOCAL_INLINE(type)` does the same thing and also requests the
+  function be inlined.  If :cfunc:`PY_LOCAL_AGGRESSIVE` is defined before
+  :file:`python.h` is included, a set of more aggressive optimizations are enabled
+  for the module; you should benchmark the results to find out if these
+  optimizations actually make the code faster.  (Contributed by Fredrik Lundh at
+  the NeedForSpeed sprint.)
+
+* :cfunc:`PyErr_NewException(name, base, dict)` can now accept a tuple of base
+  classes as its *base* argument.  (Contributed by Georg Brandl.)
+
+* The :cfunc:`PyErr_Warn` function for issuing warnings is now deprecated in
+  favour of :cfunc:`PyErr_WarnEx(category, message, stacklevel)` which lets you
+  specify the number of stack frames separating this function and the caller.  A
+  *stacklevel* of 1 is the function calling :cfunc:`PyErr_WarnEx`, 2 is the
+  function above that, and so forth.  (Added by Neal Norwitz.)
+
+* The CPython interpreter is still written in C, but  the code can now be
+  compiled with a C++ compiler without errors.   (Implemented by Anthony Baxter,
+  Martin von Löwis, Skip Montanaro.)
+
+* The :cfunc:`PyRange_New` function was removed.  It was never documented, never
+  used in the core code, and had dangerously lax error checking.  In the unlikely
+  case that your extensions were using it, you can replace it by something like
+  the following::
+
+     range = PyObject_CallFunction((PyObject*) &PyRange_Type, "lll", 
+                                   start, stop, step);
+
+.. % ======================================================================
+
+
+.. _ports:
+
+Port-Specific Changes
+---------------------
+
+* MacOS X (10.3 and higher): dynamic loading of modules now uses the
+  :cfunc:`dlopen` function instead of MacOS-specific functions.
+
+* MacOS X: a :option:`--enable-universalsdk` switch was added to the
+  :program:`configure` script that compiles the interpreter as a universal binary
+  able to run on both PowerPC and Intel processors. (Contributed by Ronald
+  Oussoren.)
+
+* Windows: :file:`.dll` is no longer supported as a filename extension for
+  extension modules.  :file:`.pyd` is now the only filename extension that will be
+  searched for.
+
+.. % ======================================================================
+
+
+.. _porting:
+
+Porting to Python 2.5
+=====================
+
+This section lists previously described changes that may require changes to your
+code:
+
+* ASCII is now the default encoding for modules.  It's now  a syntax error if a
+  module contains string literals with 8-bit characters but doesn't have an
+  encoding declaration.  In Python 2.4 this triggered a warning, not a syntax
+  error.
+
+* Previously, the :attr:`gi_frame` attribute of a generator was always a frame
+  object.  Because of the :pep:`342` changes described in section :ref:`pep-342`,
+  it's now possible for :attr:`gi_frame` to be ``None``.
+
+* A new warning, :class:`UnicodeWarning`, is triggered when  you attempt to
+  compare a Unicode string and an 8-bit string that can't be converted to Unicode
+  using the default ASCII encoding.  Previously such comparisons would raise a
+  :class:`UnicodeDecodeError` exception.
+
+* Library: the :mod:`csv` module is now stricter about multi-line quoted fields.
+  If your files contain newlines embedded within fields, the input should be split
+  into lines in a manner which preserves the newline characters.
+
+* Library: the :mod:`locale` module's  :func:`format` function's would
+  previously  accept any string as long as no more than one %char specifier
+  appeared.  In Python 2.5, the argument must be exactly one %char specifier with
+  no surrounding text.
+
+* Library: The :mod:`pickle` and :mod:`cPickle` modules no longer accept a
+  return value of ``None`` from the :meth:`__reduce__` method; the method must
+  return a tuple of arguments instead.  The modules also no longer accept the
+  deprecated *bin* keyword parameter.
+
+* Library: The :mod:`SimpleXMLRPCServer` and :mod:`DocXMLRPCServer`  classes now
+  have a :attr:`rpc_paths` attribute that constrains XML-RPC operations to a
+  limited set of URL paths; the default is to allow only ``'/'`` and ``'/RPC2'``.
+  Setting  :attr:`rpc_paths` to ``None`` or an empty tuple disables  this path
+  checking.
+
+* C API: Many functions now use :ctype:`Py_ssize_t`  instead of :ctype:`int` to
+  allow processing more data on 64-bit machines.  Extension code may need to make
+  the same change to avoid warnings and to support 64-bit machines.  See the
+  earlier section :ref:`pep-353` for a discussion of this change.
+
+* C API:  The obmalloc changes mean that  you must be careful to not mix usage
+  of the :cfunc:`PyMem_\*` and :cfunc:`PyObject_\*` families of functions. Memory
+  allocated with  one family's :cfunc:`\*_Malloc` must be  freed with the
+  corresponding family's :cfunc:`\*_Free` function.
+
+.. % ======================================================================
+
+
+.. _acks:
+
+Acknowledgements
+================
+
+The author would like to thank the following people for offering suggestions,
+corrections and assistance with various drafts of this article: Georg Brandl,
+Nick Coghlan, Phillip J. Eby, Lars Gustäbel, Raymond Hettinger, Ralf W. Grosse-
+Kunstleve, Kent Johnson, Iain Lowe, Martin von Löwis, Fredrik Lundh, Andrew
+McNamara, Skip Montanaro, Gustavo Niemeyer, Paul Prescod, James Pryor, Mike
+Rovner, Scott Weikart, Barry Warsaw, Thomas Wouters.
+
diff --git a/Doc/whatsnew/2.6.rst b/Doc/whatsnew/2.6.rst
new file mode 100644
index 0000000..b0e731a
--- /dev/null
+++ b/Doc/whatsnew/2.6.rst
@@ -0,0 +1,236 @@
+****************************
+  What's New in Python 2.6  
+****************************
+
+:Author: A.M. Kuchling
+:Release: |release|
+:Date: |today|
+
+.. % $Id: whatsnew26.tex 55963 2007-06-13 18:07:49Z guido.van.rossum $
+.. % Rules for maintenance:
+.. % 
+.. % * Anyone can add text to this document.  Do not spend very much time
+.. % on the wording of your changes, because your text will probably
+.. % get rewritten to some degree.
+.. % 
+.. % * The maintainer will go through Misc/NEWS periodically and add
+.. % changes; it's therefore more important to add your changes to
+.. % Misc/NEWS than to this file.
+.. % 
+.. % * This is not a complete list of every single change; completeness
+.. % is the purpose of Misc/NEWS.  Some changes I consider too small
+.. % or esoteric to include.  If such a change is added to the text,
+.. % I'll just remove it.  (This is another reason you shouldn't spend
+.. % too much time on writing your addition.)
+.. % 
+.. % * If you want to draw your new text to the attention of the
+.. % maintainer, add 'XXX' to the beginning of the paragraph or
+.. % section.
+.. % 
+.. % * It's OK to just add a fragmentary note about a change.  For
+.. % example: "XXX Describe the transmogrify() function added to the
+.. % socket module."  The maintainer will research the change and
+.. % write the necessary text.
+.. % 
+.. % * You can comment out your additions if you like, but it's not
+.. % necessary (especially when a final release is some months away).
+.. % 
+.. % * Credit the author of a patch or bugfix.   Just the name is
+.. % sufficient; the e-mail address isn't necessary.
+.. % 
+.. % * It's helpful to add the bug/patch number as a comment:
+.. % 
+.. % % Patch 12345
+.. % XXX Describe the transmogrify() function added to the socket
+.. % module.
+.. % (Contributed by P.Y. Developer.)
+.. % 
+.. % This saves the maintainer the effort of going through the SVN log
+.. % when researching a change.
+
+This article explains the new features in Python 2.6.  No release date for
+Python 2.6 has been set; it will probably be released in mid 2008.
+
+This article doesn't attempt to provide a complete specification of the new
+features, but instead provides a convenient overview.  For full details, you
+should refer to the documentation for Python 2.6. If you want to understand the
+complete implementation and design rationale, refer to the PEP for a particular
+new feature.
+
+.. % Compare with previous release in 2 - 3 sentences here.
+.. % add hyperlink when the documentation becomes available online.
+
+.. % ======================================================================
+.. % Large, PEP-level features and changes should be described here.
+.. % Should there be a new section here for 3k migration?
+.. % Or perhaps a more general section describing module changes/deprecation?
+.. % sets module deprecated
+.. % ======================================================================
+
+
+Other Language Changes
+======================
+
+Here are all of the changes that Python 2.6 makes to the core Python language.
+
+* An obscure change: when you use the the :func:`locals` function inside a
+  :keyword:`class` statement, the resulting dictionary no longer returns free
+  variables.  (Free variables, in this case, are variables referred to in the
+  :keyword:`class` statement  that aren't attributes of the class.)
+
+.. % ======================================================================
+
+
+Optimizations
+-------------
+
+* Internally, a bit is now set in type objects to indicate some of the standard
+  built-in types.  This speeds up checking if an object is a subclass of one of
+  these types.  (Contributed by Neal Norwitz.)
+
+The net result of the 2.6 optimizations is that Python 2.6 runs the pystone
+benchmark around XX% faster than Python 2.5.
+
+.. % ======================================================================
+
+
+New, Improved, and Deprecated Modules
+=====================================
+
+As usual, Python's standard library received a number of enhancements and bug
+fixes.  Here's a partial list of the most notable changes, sorted alphabetically
+by module name. Consult the :file:`Misc/NEWS` file in the source tree for a more
+complete list of changes, or look through the CVS logs for all the details.
+
+* A new data type in the :mod:`collections` module: :class:`NamedTuple(typename,
+  fieldnames)` is a factory function that creates subclasses of the standard tuple
+  whose fields are accessible by name as well as index.  For example::
+
+     var_type = collections.NamedTuple('variable', 
+                  'id name type size')
+     var = var_type(1, 'frequency', 'int', 4)
+
+     print var[0], var.id		# Equivalent
+     print var[2], var.type          # Equivalent
+
+  (Contributed by Raymond Hettinger.)
+
+* A new method in the :mod:`curses` module: for a window, :meth:`chgat` changes
+  the display characters for a  certain number of characters on a single line. ::
+
+     # Boldface text starting at y=0,x=21 
+     # and affecting the rest of the line.
+     stdscr.chgat(0,21, curses.A_BOLD)  
+
+  (Contributed by Fabian Kreutz.)
+
+* The :func:`glob.glob` function can now return Unicode filenames if 
+  a Unicode path was used and Unicode filenames are matched within the directory.
+
+  .. % Patch #1001604
+
+* The :mod:`gopherlib` module has been removed.
+
+* A new function in the :mod:`heapq` module: ``merge(iter1, iter2, ...)``
+  takes any number of iterables that return data  *in sorted order*,  and  returns
+  a new iterator that returns the contents of all the iterators, also in sorted
+  order.  For example::
+
+     heapq.merge([1, 3, 5, 9], [2, 8, 16]) ->
+       [1, 2, 3, 5, 8, 9, 16]
+
+  (Contributed by Raymond Hettinger.)
+
+* A new function in the :mod:`itertools` module: ``izip_longest(iter1, iter2,
+  ...[, fillvalue])`` makes tuples from each of the elements; if some of the
+  iterables are shorter than others, the missing values  are set to *fillvalue*.
+  For example::
+
+     itertools.izip_longest([1,2,3], [1,2,3,4,5]) ->
+       [(1, 1), (2, 2), (3, 3), (None, 4), (None, 5)]
+
+  (Contributed by Raymond Hettinger.)
+
+* The :mod:`macfs` module has been removed.  This in turn required the
+  :func:`macostools.touched` function to be removed because it depended on the
+  :mod:`macfs` module.
+
+  .. % Patch #1490190
+
+* New functions in the :mod:`posix` module: :func:`chflags` and :func:`lchflags`
+  are wrappers for the corresponding system calls (where they're available).
+  Constants for the flag values are defined in the :mod:`stat` module; some
+  possible values include :const:`UF_IMMUTABLE` to signal the file may not be
+  changed and :const:`UF_APPEND` to indicate that data can only be appended to the
+  file.  (Contributed by M. Levinson.)
+
+* The :mod:`rgbimg` module has been removed.
+
+* The :mod:`smtplib` module now supports SMTP over  SSL thanks to the addition
+  of the :class:`SMTP_SSL` class. This class supports an interface identical to
+  the existing :class:`SMTP`  class. (Contributed by Monty Taylor.)
+
+* The :mod:`test.test_support` module now contains a :func:`EnvironmentVarGuard`
+  context manager that  supports temporarily changing environment variables and
+  automatically restores them to their old values. (Contributed by Brett Cannon.)
+
+.. % ======================================================================
+.. % whole new modules get described in \subsections here
+
+.. % ======================================================================
+
+
+Build and C API Changes
+=======================
+
+Changes to Python's build process and to the C API include:
+
+* Detailed changes are listed here.
+
+.. % ======================================================================
+
+
+Port-Specific Changes
+---------------------
+
+Platform-specific changes go here.
+
+.. % ======================================================================
+
+
+.. _section-other:
+
+Other Changes and Fixes
+=======================
+
+As usual, there were a bunch of other improvements and bugfixes scattered
+throughout the source tree.  A search through the change logs finds there were
+XXX patches applied and YYY bugs fixed between Python 2.5 and 2.6.  Both figures
+are likely to be underestimates.
+
+Some of the more notable changes are:
+
+* Details go here.
+
+.. % ======================================================================
+
+
+Porting to Python 2.6
+=====================
+
+This section lists previously described changes that may require changes to your
+code:
+
+* Everything is all in the details!
+
+.. % ======================================================================
+
+
+.. _acks:
+
+Acknowledgements
+================
+
+The author would like to thank the following people for offering suggestions,
+corrections and assistance with various drafts of this article: .
+
diff --git a/Doc/whatsnew/3.0.rst b/Doc/whatsnew/3.0.rst
new file mode 100644
index 0000000..ac82317
--- /dev/null
+++ b/Doc/whatsnew/3.0.rst
@@ -0,0 +1,161 @@
+****************************
+  What's New in Python 3.0  
+****************************
+
+:Author: A.M. Kuchling
+
+.. |release| replace:: 0.0
+
+.. % $Id: whatsnew26.tex 55506 2007-05-22 07:43:29Z neal.norwitz $
+.. % Rules for maintenance:
+.. % 
+.. % * Anyone can add text to this document.  Do not spend very much time
+.. % on the wording of your changes, because your text will probably
+.. % get rewritten to some degree.
+.. % 
+.. % * The maintainer will go through Misc/NEWS periodically and add
+.. % changes; it's therefore more important to add your changes to
+.. % Misc/NEWS than to this file.
+.. % 
+.. % * This is not a complete list of every single change; completeness
+.. % is the purpose of Misc/NEWS.  Some changes I consider too small
+.. % or esoteric to include.  If such a change is added to the text,
+.. % I'll just remove it.  (This is another reason you shouldn't spend
+.. % too much time on writing your addition.)
+.. % 
+.. % * If you want to draw your new text to the attention of the
+.. % maintainer, add 'XXX' to the beginning of the paragraph or
+.. % section.
+.. % 
+.. % * It's OK to just add a fragmentary note about a change.  For
+.. % example: "XXX Describe the transmogrify() function added to the
+.. % socket module."  The maintainer will research the change and
+.. % write the necessary text.
+.. % 
+.. % * You can comment out your additions if you like, but it's not
+.. % necessary (especially when a final release is some months away).
+.. % 
+.. % * Credit the author of a patch or bugfix.   Just the name is
+.. % sufficient; the e-mail address isn't necessary.
+.. % 
+.. % * It's helpful to add the bug/patch number as a comment:
+.. % 
+.. % % Patch 12345
+.. % XXX Describe the transmogrify() function added to the socket
+.. % module.
+.. % (Contributed by P.Y. Developer.)
+.. % 
+.. % This saves the maintainer the effort of going through the SVN log
+.. % when researching a change.
+
+This article explains the new features in Python 3.0.  No release date for
+Python 3.0 has been set; it will probably be released in mid 2008.
+
+This article doesn't attempt to provide a complete specification of the new
+features, but instead provides a convenient overview.  For full details, you
+should refer to the documentation for Python 3.0. If you want to understand the
+complete implementation and design rationale, refer to the PEP for a particular
+new feature.
+
+.. % Compare with previous release in 2 - 3 sentences here.
+.. % add hyperlink when the documentation becomes available online.
+
+.. % ======================================================================
+.. % Large, PEP-level features and changes should be described here.
+.. % Should there be a new section here for 3k migration?
+.. % Or perhaps a more general section describing module changes/deprecation?
+.. % sets module deprecated
+.. % ======================================================================
+
+
+Other Language Changes
+======================
+
+Here are all of the changes that Python 2.6 makes to the core Python language.
+
+* Detailed changes are listed here.
+
+.. % ======================================================================
+
+
+Optimizations
+-------------
+
+* Detailed changes are listed here.
+
+The net result of the 3.0 optimizations is that Python 3.0 runs the pystone
+benchmark around XX% slower than Python 2.6.
+
+.. % ======================================================================
+
+
+New, Improved, and Deprecated Modules
+=====================================
+
+As usual, Python's standard library received a number of enhancements and bug
+fixes.  Here's a partial list of the most notable changes, sorted alphabetically
+by module name. Consult the :file:`Misc/NEWS` file in the source tree for a more
+complete list of changes, or look through the CVS logs for all the details.
+
+* Detailed changes are listed here.
+
+.. % ======================================================================
+.. % whole new modules get described in \subsections here
+
+.. % ======================================================================
+
+
+Build and C API Changes
+=======================
+
+Changes to Python's build process and to the C API include:
+
+* Detailed changes are listed here.
+
+.. % ======================================================================
+
+
+Port-Specific Changes
+---------------------
+
+Platform-specific changes go here.
+
+.. % ======================================================================
+
+
+.. _section-other:
+
+Other Changes and Fixes
+=======================
+
+As usual, there were a bunch of other improvements and bugfixes scattered
+throughout the source tree.  A search through the change logs finds there were
+XXX patches applied and YYY bugs fixed between Python 2.6 and 3.0.  Both figures
+are likely to be underestimates.
+
+Some of the more notable changes are:
+
+* Details go here.
+
+.. % ======================================================================
+
+
+Porting to Python 3.0
+=====================
+
+This section lists previously described changes that may require changes to your
+code:
+
+* Everything is all in the details!
+
+.. % ======================================================================
+
+
+.. _acks:
+
+Acknowledgements
+================
+
+The author would like to thank the following people for offering suggestions,
+corrections and assistance with various drafts of this article: .
+
-- 
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